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  • 1
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    Leading specialist of fish processing industry, scientist and lecturer Vinnov Aleksey Sergeevich (2019)
    Details
    Publication Date: 2021-05-19
    Description: Aleksey Sergeevich Vinnov (25.05.1958 – 04.06.2019) was a Candidate of Sciences (Engineering), an Associate Professor, a talented lecturer, a rector of the Kerch Maritime Technological Institute (KMTI) in 2000–2005, a Senior Researcher in the FSBSI “Southern Scientific Research Institute of Marine Fisheries and Oceanography” (YugNIRO), and a Deputy Head for Operation and Quality of the Limited Liability Company under the Laws of Russian Federation “Aquamarine”. A.S. Vinnov made a great contribution into the development of education and science in the field of fisheries. Aleksey Sergeevich began his professional life as a Junior Researcher in the Astrakhan Technical Institute of Fishing Industry and Economy and defended his Candidate's Thesis in 1988. He dedicated the major part of his working career to the Kerch State Maritime Technological University, where he had been employed for 21 years, taking positions from a senior lecturer of the Department of Fish Processing Technology, an Associate Professor, the Dean of the Technological Faculty, the vice-rector for academic affairs, to the rector of the University. A.S. Vinnov was known for his rational thinking and professional integrity; he was diplomatic and considerate, and proved to be a competent leader. Vinnov's research works were dedicated to the issues of development of production technology for canned fish and fish protein mass, of kinetics of enzymatic hydrolysis, and many other subjects. A.S. Vinnov was honored with several badges of distinction due to his high professional expertise and personal contribution to the development of fisheries field, particularly education.
    Description: Алексей Сергеевич Виннов (25.05.1958 – 04.06.2019 гг.) — кандидат технических наук, доцент, талантливый преподаватель, ректор Керченского морского технологического института с 2000 по 2005 г. (КМТИ), старший научный сотрудник ФГБНУ «Южный научно-исследовательский институт рыбного хозяйства и океанографии» (ЮгНИРО), заместитель директора по производству и качеству ООО «Аквамарин». А.С. Виннов внес огромный вклад в развитие образования и науки рыбной отрасли. Свою трудовую деятельность Алексей Сергеевич начал в должности младшего научного сотрудника Астраханского технического института рыбной промышленности и хозяйства, успешно защитив в 1988 г. кандидатскую диссертацию. Большую часть своей трудовой деятельности он посвятил Керченскому государственному морскому технологическому университету, проработав здесь 21 год в должностях от старшего преподавателя кафедры технологии рыбных продуктов, доцента, декана технологического факультета, проректора по учебной работе до ректора университета. А.С. Виннов обладал рациональным мышлением, был очень грамотным, тактичным человеком, умелым руководителем. Научная деятельность Алексея Сергеевича была посвящена изучению вопросов усовершенствования технологии рыбных консервов, рыбных белковых масс, кинетики ферментативного гидролиза, а также многим другим. За личный вклад в развитие образования и рыбной отрасли, за высокий профессионализм А.С. Виннов был удостоен ряда почетных знаков отличия.
    Description: Published
    Keywords: Researchers ; Engineering ; Fish processing ; Canned food ; Rector ; Proteins ; Hydrolysis
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.91-95
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  • 2
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    Study of Ecology and the Potential for Exploiting Saline Surface Waters of Fars Province in Aquaculture- Dehram River (2018)
    Iranian Fisheries Science Research Institute | Tehran, Iran
    Details
    Publication Date: 2021-05-19
    Description: Aquaculture activity is restricted mainly to rainbow trout in cold waters and carps in warm waters in inland waters of Iran as well as Fars Province. Probably for this reason saline waters of south and southeast Fars have not been used for aquaculture. These rivers are ecosystems with a diverse biota, it is predictable that can be found some there endemic aquatic organisms with a potential for aquaculture. Finding a suitable organism can help increase wise use of this natural resource, and local production and recruitment. However, it is highly needed to investigate various environmental elements prior to any use to obtain an estimation of the environmental consequences, parallel to finding usage potentials. In This study, we investigated Dehram saline river in south of Fars Province. Hydrological and physiographical properties, chemical composition of the river, and aquatic populations were sampled and measured monthly in 3 stations in one year. Salinity, electrical conductivity, and total dissolved solids increased from station 1 to 3, reaching from 6.6 g/L, 14.3 g/L, and 12800 µs/cm to 13.5 g/L, 17.7 g/L, and 16500 µs/cm, respectively. Dissolved oxygen and oxygen saturation were higher in station 3, and in autumn and winter. Nitrite showed lowest values in winter (0.006 mg/L) and highest values in spring (0.013 mg/L). Nitrate showed the lowest concentration in station 3 (0.43 mg/L), but no differences were seen among seasons. Ammonium showed no differences among stations or seasons. Phosphate levels in station 1 and 3 were 0.13 mg/L‌to 0.17 mg/L, with the highest level (0.29 mg/L) seen in the spring. Five species of fishes were identified in the river, which all were widely favored by local people. Some of these have been categorized as edible in previous studies, others as ornamental. On the other hand, intensive growth of an algal species throughout the river demonstrates a potential for algal cultivation. Significant role of algae in production of food for both man and livestock is now well recognized in aquaculture industry.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Ecology ; Dehram River ; Limnology ; Saline water ; Physico-chemical parameters ; Aquaculture
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 62pp.
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  • 3
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    Limnological survey about brakish water pond culture of rainbow trout (2018)
    Iranian Fisheries Science Research Institute | Tehran, Iran
    Details
    Publication Date: 2021-05-19
    Description: Limnological factors of brackish water pounds of the rainbow trout, Onchorhynchus mykiss were studied at Bafgh region in Yazd province. Physicochemical factors, phytoplankton, zooplankton and benthic populations of pools, supply and drainage channels from different farms were studied in aquaculture cycle in 2002 and 2003. Means were compared using Tukey HSD and t tests. Meanings of factors in 2002 and 2003 were respectively: and 9.3 0.2ppt; dissolved oxygen 7.9 0.2mg/l water temperature 13.8 0.3°c and 14.9 0.6°c; salinity 12.3 0.2ppt and 7.2 0.1mg/l; pH between 7.8 to 9.2 and 8.1 to 9.5; depth of hyalinity 0.85 0.1m and 1.1 0.1m; ammonium 0.1-0.5mg/l; and nitrate 1.8-21mg/l. Main phytoplankton were diatoms specially Chaetoceros, and Cyanophyta. Rotifera were the dominant zooplankton. Benthic fauna mainly included immature Chironomids. Final mean lengths were between 24.7cm to 31.5cm, mean weights between 11179.9gr to 434.6gr. FCR between 1.16 to 1.6; DGR between 1.04gr/day to 3.03gr/day; production 0.03kg/m2 to 0.84 kg/m2. Supply channels had the optimum limnological condition for trout aquaculture. Limnological factors were often not significantly different between pools and drainage channels. Saeeid and Rangin-Kaman farms were the most successful farms.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Limnology ; Brackish water ; Onchorhynchus mykiss ; Rainbow trout ; Phytoplankton ; Zooplankton ; Chaetoceros ; Survey ; Pond culture
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 175pp.
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  • 4
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    Limnological investigating on Gahar-roud River and study of feasibility of exopoliting for cold-water fish culture (2018)
    Iranian Fisheries Science Research Institute | Tehran, Iran
    Details
    Publication Date: 2021-05-19
    Description: Gahar-roud is in 18 kilometer far from Doroud city from East of lorestan province . This river orginated from internal part of Oshteran-kouh mountain altitude and Gahar-Lake . Survey on Gahar roud Limnology began from the end of 2001 year and during the 18 month achived, at first on the length of 20 kilometer five station of sampling was selected and biological, physical and chemical character of this river was surveyed this river in all path of it feeding with large and small spring, little rivers and water of icehouse. The amount water of this river is different and maximum water is about 21 m/s in April month. Specifity of this river is be enough the temperature of water for fish. Minimum in the Jan is about 3 centigrad deegree and maximum is July and Aug about 24 centigrade deegree phis between 6.5-8.2 and is few basic . solauble oxigen is enough and is between 8.5-13 mg/lit.during the year.This river is very bright and haven t the source of polution and during the path of river and be enaugh the dosage of mineral in water are the important physical and chemical character of this river. Gahar-roud is not biological hardness quality. About 31 genus and species from 5 family of phytoplangton and 42 genus from 26 family from the order of insects, molusca, worms and crustacea and 9 species from 12 family from the side aquatic. Plants was collected and recognized. Based on ecological potential of this region, because Gahar- roud river is poor for food material and classified in oligotroph river and hasn t high biological value. And also have a few population and in fact haven t any population and based on the safer system belong to the quatiy elass of oligotroph and amount of water, regular circulation of water with microclima condition rate of natural resource land around river, having program for culture of cold water fish is important but it is better that use from culture of fish, be regulated key word limnology, Gahar-roud, river plangton, bentoz, fish.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Limnology ; Fish ; Bentos ; Plankton
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 84pp.
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  • 5
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    Effects of drought on ecological properties and water quality of Dorudzan Reservoir (2018)
    Iranian Fisheries Science Research Institute | Tehran, Iran
    Details
    Publication Date: 2021-05-19
    Description: Dorudzan reservoir is the main provider of drinking water for the capital Shiraz, as well as the most significant storage of water in the Kor river course. In addition of eroded material, a load of agricultural outputs from upstream are moved to the lake every year. Main physiographic, physical and chemical, and biological components of the lake were monthly sampled and analysed from Novembr 2010 to October 2011. Mean annual measures were water temperature 16.7 ˚C (SD=5.8), pH 8.2 (SD=0.3), dissolved oxygen 7.6 mg/l (SD=1.7), ammonium 0.05 mg/l (SD=0.08), nitrite 0.004 mg/l (SD=0.003), nitrate 0.44 mg/l (SD=0.44), phosphate 0.20 mg/l (SD=0.23), silicate 7.00 mg/l (SD=2.49), BOD 2.29 mg/l (SD=1.00), COD 24.49 mg/l (SD=15.47), electrical conductivity 720 µs/cm (SD=219), total dissolved solids 457.67 mg/l (SD=138.72), calcium hardness 61.30 mg/l (SD=13.45), and magnesium hardness 20.23 mg/l (SD=9.18). Living parts of the ecosystem including species of fish, orders and families of benthic invertebrates, zooplanktons, and phytoplanktons were investigated. Benthic macroinvertebrates included various nematodes, oligochates, gastropods, bivalves, and insect larvae (dipteral and coleptera), most abundant of which were dipteran larvae, mollusks, and nematodes. Dominant zooplankton was Bosmina, with Daphnia and Cyclops in next ranks. Among rotifer, Trichocera was more abundant than Lecanae. Bosmina showed the most abundance in summer and Daphnia in spring. Trichocera had its most abundance in summer as well, while Lecanae was more abundant in Automn and winter. A total of 41 algal genera from 8 divisions were found. Dominant phytoplankton division was Chlorophyta, with genus Pediastrum. Dominant microalga was Dynobrion (Chrysophyta) in Spring, Cylindrospermum and (both Cyanophyta) in Summer, Microsystis in Automn, and Ceratium (Dynophyta) in Winter. Ceratium were found in all seasons in most of the sampling sites, and showed highest abundance compared to other genera of its division. Dominant genus of diatoms was Fragilaria. Fish populations include Alburnus mossulensis, Capoeta aculeate, Capoeta damascina, Carasobarbus luteus, Carassius gibelio, Cyprinus carpio, and Hypophthalmichthys molitrix. Main different parts of the lake showed quite different composition of fish species. An epidemic occurance of the crustacean ectoparasite Lernea cyprinacea among most fishes was another important finding. These findings will serve as a base for future studies as a set point of drought situations.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Limnology ; Reservoir ; Plankton ; Fish ; Alburnus mossulensis ; Capoeta aculeate ; Capoeta damascina ; Carasobarbus luteus ; Carassius gibelio ; Cyprinus carpio ; Hypophthalmichthys molitrix
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 72pp.
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  • 6
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    Study of limnology of Abbaric river in Kerman Province (2018)
    Iranian Fisheries Science Research Institute | Tehran, Iran
    Details
    Publication Date: 2021-05-19
    Description: Abbarik River is an important river in Kerman. Study of limnology of Abbarik River for aquatics & culture was started from Mehr 1381 to Day 1382. Base of this study was physical- chemical and Biological factors. In this research 3 stations was appointed. PH- oxygen- salinity- Ca- Mg- Na- K- Cl and was majored and bentetic- fish was recognized. This study was achievement in 4 season and twice in month. Bentosis recognize was Ephemeroptera- Diptera- Anisoptera- Cleoptera Trichoptera Fishes recognize was Capoeta damascina- Nemachilus sargadensis- Cyprinion watsoni.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Physical ; Chemical ; Biological ; Limnology ; Bentosis fish ; Aquatic ; Culture ; PH ; Salinity ; Oxygen ; Ephemeroptera ; Diptera ; Anisoptera ; Cleoptera Trichoptera ; Capoeta damascina ; Nemachilus sargadensis ; Cyprinion watsoni
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 44pp.
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  • 7
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    The Accomplition of limnologic Study of Shiroud River (West of Mazandaran) (2018)
    Iranian Fisheries Science Research Institute | Tehran, Iran
    Details
    Publication Date: 2021-05-19
    Description: The shiroud river is one of the important riveres in point of view of fisheries matter which located in western part of Mazndran provience. The project of Limnological study have done in this river during June/ 2002 - Jun / 2003 for more and better underestanding situations, of biological and nonbiological parameters like as phytoplankton, zooplonkton, benthoses, Ichthyology, physico - chemical and pesticides of water. - Physico- chemical paramaters by ASTM methods and spectrophotometer and pestisides by US-EPA- method and GC- ECD determined. The procedures of detemination of zooplanklon and phytoplankton by manuals of Newell, 1970 and Sorina, 1974 idantify and determined respectinely. In Ichthyology, by manual procedure Berg, 1949 identifind. The sampeling have been in four stations during four seasons and result as follow: - The maximum and minimum amount of pH were in station 5 (spring) and Station no. 4 (summer) 8.19 and 7.75 respectively. - The maximum and minimum temperature of water were in station no. 8 (summer) and stations no. 2 (winter) 27.7 c and 7.7c respectively. The fluctuatcions of nutroients datas of this study and other studies done during last 5 years showed, there were not big diffrence between them but also these datas were very close to each other. - The maximum residues of pesticides for heptachlor Epoxide (Winter ) and Lindane (spring) betweenresidues of sixteen pesticdes were 79.4 and 3.7 ppb respectively. - The maximum and minimum amount of phytoplankton biomass belong to chrysophyta during four seasons were 2572 through 1081 mg/m3. - The percentage of zooplankton belong to Rotatoria , Protozoa , Copepoda , Cladocera and Zoobenthos were in 41 , 31 , 12 , 4 and 12 percent recpectively. - The maximum aboundant percentage of bentheic animals belong to Diptera with 42 percent and were dominate whole sampeling stations . - The abundence of fishes in this river belong to two species of C. capoeta gracilis and Al. bipunctatus were catched in four seasons at eight stations . The percentages of C. capoeta gracilis species were catched in four seasons at eight stations during winter, summer , spring and fall with 96 ,81 , 73 and 67 percent respectively. The percentages of Al. bipunctatus species were catched in four seasons at eight stations during winter, summer , spring and fall with 47 , 44 , 43 and 40 percent respectively.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Pesticdes residues ; Phytoplankton ; Zooplankton ; Riverine fishes ; Nutrients ; Limnology ; ASTM ; Rotatoria ; Protozoa ; Copepoda ; Cladocera ; Zoobenthos
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 127pp.
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  • 8
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    История исследований и разработок орудий и техники лова лабораторией промышленного рыболовства ЮгНИРО (2018)
    Kerch Branch ("YugNIRO") of FSBSI "AzNIIRKH" | Kerch, Crimea
    Details
    Publication Date: 2021-05-19
    Description: Наряду с исследованиями по определению сырьевой базы Азово-Черноморского бассейна, при создании института АзЧерНИРО в 1933 г. была сразу организована научно-исследовательская лаборатория техники лова рыбы. За все время функционирования этого подразделения такие специалисты, как С.С. Виннов, О.И. Саковец, С.Я. Наместников, Е.Е. Шапунов, В.М. Кириллов, В.Г. Герасимов, В.С. Долбиш, Н.Г. Думин, В.Г. Васильев, А.А. Яковлев, Е.С. Деньгин, В.И. Абакаров, В.Н. Миронов, В.В. Стрельцов, А.С. Вайнерман, В.К. Яшкин, Ю.В. Шишов, А.М. Стафикопуло в течение многих лет вносили огромный вклад в развитие рыболовства в Азово-Черноморском бассейне и Мировом океане. До 1950 г. траловый промысел в Черном море отсутствовал, хотя были известны попытки внедрить этот вид лова в черноморское рыболовство. Так, в начале 1909 г. в северо-западной части Черного моря работал траулер «Федя». К концу 1911 г. количество траулеров, которые работали в данном регионе моря, увеличилось до 9 судов. Уловы состояли на 98-99 % из осетровых и на 1-2 % из камбалы. Ввиду очень большого вылова молоди осетровых рыб траловый промысел вскоре был запрещен. В 1932 г. из Мурманска для выяснения эффективности тралового лова в Черном море был послан рыболовный траулер «Абрек». Почти у всего черноморского побережья пробовали ловить отечественным промысловым тралом, применяемым в Баренцевом море для добычи трески. При этом отмечалось, что уловы камбалы были очень низкими. Очевидно, одной из причин была неприспособленность самой конструкции трала для лова этого вида рыб. В конце 1933 г. траулер вернулся в Мурманск. В 1949 г. Черноморская научно-промысловая экспедиция возобновила работы по освоению тралового лова в Черном море. Перед экспедицией стояла задача всесторонне изучить ихтиофауну моря и выяснить возможности применения ряда поисковых орудий лова, в том числе донного трала. С этой целью было разработано и испытано несколько типов донных тралов. С конца 1949 г. были начаты исследования по разработке конструкции разноглубинного трала для Черного моря. К тому времени инженерами М.К. Кокоревым, В.Ф. Шушпановым и А.Н. Потехиным была разработана специальная подъемно-распорная система. В соответствии с ее техническими данными в дальнейшем проектировались сетные части трала. Первый проект опытного рыболовного разноглубинного морского трала разрабатывался для лова мелких черноморских пелагических рыб в толще воды, на глубинах от 0 до 100 м, с одного судна. Большой вклад в развитие тралового промысла в Черном море внес А.Н. Самарянов.
    Description: Published
    Keywords: Engineering ; Fishing gear ; Fishing fleet ; Fishing vessels ; Trawlers ; Anchovy fisheries ; Sprat fisheries ; Purse fishing ; Commercial species ; Mullets
    Repository Name: AquaDocs
    Type: Conference Material , Non Refereed
    Format: pp.247-254
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  • 9
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    Matamek annual report for 1977 (2018)
    Woods Hole Oceanographic Institution
    Details
    Publication Date: 2022-05-26
    Description: This is a report describing activities associated with the Matamek program in 1977. Research was conducted on biological, chemical and physical factors related to salmonid production in Matamek River and Matamek Lake. Canadian universities, the Quebec government and Woods Hole Oceanographic Institution cooperated in the program.
    Description: Supported by Woods Hole Oceanographic Institution and the Department of Tourism, Fish and Game of the Province of Quebec.
    Keywords: Ecology ; Limnology
    Repository Name: Woods Hole Open Access Server
    Type: Technical Report
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  • 10
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    Spraying makes it smoother (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-08-17
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 11
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    3D printed polyamide membranes for desalination (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-08-17
    Description: Polyamide thickness and roughness have been identified as critical properties that affect thin-film composite membrane performance for reverse osmosis. Conventional formation methodologies lack the ability to control these properties independently with high resolution or precision. An additive approach is presented that uses electrospraying to deposit monomers directly onto a substrate, where they react to form polyamide. The small droplet size coupled with low monomer concentrations result in polyamide films that are smoother and thinner than conventional polyamides, while the additive nature of the approach allows for control of thickness and roughness. Polyamide films are formed with a thickness that is controllable down to 4-nanometer increments and a roughness as low as 2 nanometers while still exhibiting good permselectivity relative to a commercial benchmarking membrane.
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 12
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    Zeolitic imidazolate framework membranes made by ligand-induced permselectivation (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-09-07
    Description: Zeolitic imidazolate framework (ZIF) membranes are emerging as a promising energy-efficient separation technology. However, their reliable and scalable manufacturing remains a challenge. We demonstrate the fabrication of ZIF nanocomposite membranes by means of an all-vapor-phase processing method based on atomic layer deposition (ALD) of ZnO in a porous support followed by ligand-vapor treatment. After ALD, the obtained nanocomposite exhibits low flux and is not selective, whereas after ligand-vapor (2-methylimidazole) treatment, it is partially transformed to ZIF and shows stable performance with high mixture separation factor for propylene over propane (an energy-intensive high-volume separation) and high propylene flux. Membrane synthesis through ligand-induced permselectivation of a nonselective and impermeable deposit is shown to be simple and highly reproducible and holds promise for scalability.
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 13
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    Robotic-flapper maneuvers and fruitfly turns (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-09-14
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    A tailless aerial robotic flapper reveals that flies use torque coupling in rapid banked turns (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-09-14
    Description: Insects are among the most agile natural flyers. Hypotheses on their flight control cannot always be validated by experiments with animals or tethered robots. To this end, we developed a programmable and agile autonomous free-flying robot controlled through bio-inspired motion changes of its flapping wings. Despite being 55 times the size of a fruit fly, the robot can accurately mimic the rapid escape maneuvers of flies, including a correcting yaw rotation toward the escape heading. Because the robot’s yaw control was turned off, we showed that these yaw rotations result from passive, translation-induced aerodynamic coupling between the yaw torque and the roll and pitch torques produced throughout the maneuver. The robot enables new methods for studying animal flight, and its flight characteristics allow for real-world flight missions.
    Keywords: Engineering
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Hop, skip, jump, or massive leap (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-04-27
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Flying fast and free (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-09-14
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Behind the scenes of the built environment (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-03-09
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    The art of manufacturing molecules (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-01-19
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Variabilidade ambiental e a distribuição de abundância de copépodes (Crustacea: Copepoda) de planícies de inundação neotropicais. (2017)
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Details
    Publication Date: 2022-05-13
    Description: The environmental variables are important in the functioning and dynamics of freshwater ecosystems, since changes in physical and chemical conditions of these environments contribute to alterations in the ecological functioning. This research was conducted in four neotropical flood plains: Amazônica, Araguaia, Pantanal e Paraná. The samples of zooplankton were performed in the subsurface region of limnetic lakes each floodplain, in the years 2011 and 2012 (dry and wet). At the same time the environmental variables were measured and obtained water samples for later laboratory analysis. Our goal was to investigate the effect of environmental variables in the abundance of copepods, and the following hypothesis was tested: HI) the abundance of copepods has a great set with environmental variables, and extremes range of environmental variation, the lower the abundance of these organisms, unimodal effect. Local factors (physical and chemical environmental conditions) determined the abundance of copepods, as well as the environmental gradient showed a close relationship in the spatial and temporal distribution of the species, being possible to observe higher abundance at specific levels of environmental variables (toward the great). Studies that focus on tolerance limits of the species and their relationships with environmental conditions has risen in recent years, as the anthropogenic changes in climate and natural environments has caused significant changes in community structure, facilitating the invasion by non-native species and loss species diversity and the consequent change in ecosystem functioning. However, the hypothesis (HI) was partially supported, as the abundance follows a pattern of rise towards the great, but it was not possible to clearly unimodal effect on abundance for many species.
    Description: As variáveis ambientais têm papel relevante no funcionamento e dinâmica de ambientes aquáticos continentais, uma vez que, mudanças nas condições físicas e químicas desses ambientes contribuem para alterações no padrão de funcionamento ecológico. Esta investigação foi realizada em quatro planícies de inundação neotropicais: Amazônica, Araguaia, Pantanal e Paraná. As coletas de organismos zooplanctônicos foram realizadas na subsuperfície da região limnética das lagoas de cada planície de inundação, nos anos de 2011 e 2012 (seca e cheia). Ao mesmo tempo foram medidas as variáveis ambientais e obtidas amostras de água para posterior análise em laboratório. O nosso objetivo foi investigar o efeito das variáveis ambientais na abundância dos copépodes, e foi testada a seguinte hipótese: HI) a abundância de copépodes possui um ótimo estabelecido com as variáveis ambientais, e em extremos de amplitude de variação ambiental, menor será a abundância desses organismos, efeito uninodal. Os fatores locais (condições físicas e químicas do ambiente) determinaram a abundância de copépodes, bem como a variação ambiental apresentou uma estreita relação na distribuição espacial e temporal das espécies, sendo possível observar maiores valores de abundância em níveis específicos das variáveis ambientais (direção ao ótimo). Estudos que focam nos limites de tolerância das espécies e suas relações com as condições ambientais tem ressurgido nos últimos anos, pois as alterações antropogênicas no clima e nos ambientes naturais tem causado expressivas mudanças na estrutura da comunidade, facilitação à invasão por espécies não nativas e perda da diversidade de espécies e a consequente alteração no funcionamento ecossistêmico. Contudo, a hipótese (HI) foi parcialmente corroborada, pois a abundância segue um padrão de ascensão em direção ao ótimo, porém não foi possível estabelecer claramente para muitas espécies um efeito unimodal na distribuição da abundância.
    Description: Masters
    Keywords: Copepoda ; Ciências Ambientais ; Ecology ; Community ; Abundance ; Spatial distribution ; Niche ; Brazil ; Temporal distribution ; Abundância ; Limnologia ; Distribuição espacial ; Nicho ; Copépodes (Crustacea: Copepoda) ; Planícies de inundação ; Comunidades, Ecologia de ; Brasil ; Distribuição temporal ; Limnology
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 37pp.
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    The volume and mean depth of Earth's lakes (2017)
    John Wiley & Sons
    Details
    Publication Date: 2022-05-26
    Description: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Geophysical Research Letters 44 (2017): 209–218, doi:10.1002/2016GL071378.
    Description: Global lake volume estimates are scarce, highly variable, and poorly documented. We developed a rigorous method for estimating global lake depth and volume based on the Hurst coefficient of Earth's surface, which provides a mechanistic connection between lake area and volume. Volume-area scaling based on the Hurst coefficient is accurate and consistent when applied to lake data sets spanning diverse regions. We applied these relationships to a global lake area census to estimate global lake volume and depth. The volume of Earth's lakes is 199,000 km3 (95% confidence interval 196,000–202,000 km3). This volume is in the range of historical estimates (166,000–280,000 km3), but the overall mean depth of 41.8 m (95% CI 41.2–42.4 m) is significantly lower than previous estimates (62–151 m). These results highlight and constrain the relative scarcity of lake waters in the hydrosphere and have implications for the role of lakes in global biogeochemical cycles.
    Description: Knut and Alice Wallenberg Foundation; National Science Foundation Graduate Research Fellowship Program Grant Number: 2388357; National Science Foundation Grant Number: OCE-1315201
    Keywords: Limnology ; Topograhy ; Scaling ; Volume ; Mean depth
    Repository Name: Woods Hole Open Access Server
    Type: Article
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    Fast exoskeleton optimization (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-06-23
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Optimum human input (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-06-23
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    [Editors' Choice] Lighting the way to fluorine placement (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-03-03
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Filtering through to what's important (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-06-16
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Human-in-the-loop optimization of exoskeleton assistance during walking (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-06-23
    Description: Exoskeletons and active prostheses promise to enhance human mobility, but few have succeeded. Optimizing device characteristics on the basis of measured human performance could lead to improved designs. We have developed a method for identifying the exoskeleton assistance that minimizes human energy cost during walking. Optimized torque patterns from an exoskeleton worn on one ankle reduced metabolic energy consumption by 24.2 ± 7.4% compared to no torque. The approach was effective with exoskeletons worn on one or both ankles, during a variety of walking conditions, during running, and when optimizing muscle activity. Finding a good generic assistance pattern, customizing it to individual needs, and helping users learn to take advantage of the device all contributed to improved economy. Optimization methods with these features can substantially improve performance.
    Keywords: Engineering
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Making the future (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-11-24
    Keywords: Engineering
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Comment on "Water harvesting from air with metal-organic frameworks powered by natural sunlight" (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-12-01
    Description: Kim et al . (Reports, 28 April 2017, p. 430) presented results for the solar-driven harvesting of water from air via metal-organic frameworks as a prodigious potential advance toward remedying global water shortages. Basic thermodynamics and a survey of multiple off-the-shelf technologies show that their approach is vastly inferior in efficiency (and thereby in feasibility) to available alternatives.
    Keywords: Engineering
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    To frack or not to frack (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-12-01
    Keywords: Engineering
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 29
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    Response to Comment on "Water harvesting from air with metal-organic frameworks powered by natural sunlight" (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-12-01
    Description: In their comment, Bui et al . argue that the approach we described in our report is vastly inferior in efficiency to alternative off-the-shelf technologies. Their conclusion is invalid, as they compare efficiencies in completely different operating conditions. Here, using heat transfer and thermodynamics principles, we show how Bui et al .’s conclusions about the efficiencies of off-the-shelf technologies are fundamentally flawed and inaccurate for the operating conditions described in our study.
    Keywords: Engineering
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Coupling between distant biofilms and emergence of nutrient time-sharing (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-05-12
    Description: Bacteria within communities can interact to organize their behavior. It has been unclear whether such interactions can extend beyond a single community to coordinate the behavior of distant populations. We discovered that two Bacillus subtilis biofilm communities undergoing metabolic oscillations can become coupled through electrical signaling and synchronize their growth dynamics. Coupling increases competition by also synchronizing demand for limited nutrients. As predicted by mathematical modeling, we confirm that biofilms resolve this conflict by switching from in-phase to antiphase oscillations. This results in time-sharing behavior, where each community takes turns consuming nutrients. Time-sharing enables biofilms to counterintuitively increase growth under reduced nutrient supply. Distant biofilms can thus coordinate their behavior to resolve nutrient competition through time-sharing, a strategy used in engineered systems to allocate limited resources.
    Keywords: Engineering
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Maximizing growth by sharing (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-05-12
    Keywords: Engineering
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    [This Week in Science] Stitching a belt out of carbon rings (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-04-14
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    [Perspective] Allotropy by design—Carbon nanohoops (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-04-14
    Description: The allotropes formed by carbon reflect differences in its bonding: single bonds in diamond, double bonds in graphite and graphene, and triple bonds in polyynes. Fashioning graphene sheets into bowls, monkey saddles, balls, and tubes has led to a number of molecular allotropes of carbon or carbon-rich quasi-allotropes with novel topologies and shapes. A simple ring of carbon can be reduced to practice in various forms (1): a cyclic array of carbon atoms, a “pearl necklace” of benzene rings, or a cylindrical hoop of flank-fused benzenes, just to name a few. On page 172 of this issue, Povie et al. (2) report on the synthesis of an angular-fused hoop structure, which has been a long-standing target. Author: Jay S. Siegel
    Keywords: Organic Chemistry
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    [This Week in Science] Stitching one alkyl group to another (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-04-14
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    [This Week in Science] Boron choreographs a double reaction (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-03-03
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    [Book Review] Building the future (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-02-17
    Description: Engineering has an image problem. The phrase "engineering disaster" rolls off the tongue, while great technical achievements are more often heralded as "scientific miracles." Enter Dream Big. Sponsored by the American Society of Civil Engineers with support from Bechtel Corporation, the film sets out to reframe engineering as a force for good and a profession in service to people and the planet. Author: Donna Riley
    Keywords: Engineering
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    A cirrus cloud climate dial? (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-07-21
    Keywords: Engineering
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Sulfur injections for a cooler planet (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-07-21
    Keywords: Engineering
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 39
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    [This Week in Science] Turning benzene into a C–H bond cleaver (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-04-01
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Turbines can use CO2 to cut CO2 (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-05-26
    Keywords: Engineering
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Engineered emotions (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-11-10
    Keywords: Engineering
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 42
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    [This Week in Science] A cyclic catalyst to pair up sugars (2017)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2017-01-13
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    Contribution à l'étude écologique du lac Ichkeul (Tunisie septentrionale). (2016)
    Details
    Publication Date: 2021-05-19
    Description: This work includes a study of the ecological characteristics and of the distribution of floristic and faunistic communities in a muddy lagoon with large fluctuations of salinity.
    Description: Ce travail est une étude des conditions écologiques générales et de la répartition des peuplements végétaux et animaux dans une lagune envasée soumise à de grandes fluctuations de salinité.
    Description: Published
    Keywords: Salinity ; Lakes ; Climate ; Limnology ; Water analysis ; Sediment analysis ; Freshwater ecology ; Brackish ; Freshwater
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp 115-124
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    [Perspective] Solar-powering the Internet of Things (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2016-07-08
    Description: The Internet connects billions of computational platforms of various sizes, from supercomputers to smart phones. However, the same types of data transmission can connect computational resources to much simpler sensors “at the edge of the net” that collect, analyze, and transmit data, as well as controllers that receive instructions. Devices deployed in the environment, homes and offices, and even our bodies would expand the number of connected devices to the trillions. This “Internet of Things” (IoT) underlies the vision of smart homes and buildings that could sense and transmit their status and respond appropriately (1), or track and report on the state of objects (vehicles, goods, or even animals) in the environment. However, the practical implementation of the IoT has been relatively slow, in part because all of these edge devices must draw electrical power from their local environment. We analyze the use of photovoltaics (PV) to power devices and help bring the IoT to fruition. Authors: Richard Haight, Wilfried Haensch, Daniel Friedman
    Keywords: Engineering
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    [Editors' Choice] Carboxylating stubborn alkyl chlorides (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-07-08
    Description: Author: Phil Szuromi
    Keywords: Organic Chemistry
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    [This Week in Science] Olefins enlisted to attack ketones (2016)
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    In: Science
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    Publication Date: 2016-07-08
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    [This Week in Science] A radical route to ophiobolin rings (2016)
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    In: Science
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    Publication Date: 2016-05-27
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    [This Week in Science] A light approach to C-N bond formation (2016)
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    In: Science
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    Publication Date: 2016-07-15
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 49
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    [Editors' Choice] Iron takes alcohols to carboxylic acids (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2016-07-22
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 50
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    [This Week in Science] Catalysis gets all tied up in knots (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-06-24
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 51
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    [This Week in Science] Adding two fluorines to just one carbon (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-07-01
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 52
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    [Perspective] Three catalysts for activating carbon-hydrogen bonds (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2016-06-10
    Description: Transition metal–catalyzed arylation of C–H bonds has been intensively studied for forming C–C bonds in complex-molecule synthesis (1). An acidic C–H bond (for example, one near a double bond or an O atom) is cleaved to form a carbon–metal bond, which then couples to arene. Many of these organometallic species can be generated catalytically. Much less research has dealt with unreactive nonacidic sp3 C–H bond functionalization (3). On page 1304 of this issue, Shaw et al. (3) report an efficient and general method that focuses on arylation of sp3 C–H bonds at carbon atoms adjacent to amines and to cyclic ethers by combining nickel, visible-light photoredox, and hydrogen-atom transfer (HAT) catalysis. Author: Corinne Fruit
    Keywords: Organic Chemistry
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 53
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    [This Week in Science] A tip of the HAT to C-C bond formation (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2016-06-10
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 54
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    [This Week in Science] A rhodium route from C-H to C-N bonds (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-09-09
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 55
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    [This Week in Science] Copper-catalyzed radical relay (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-09-07
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 56
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    [In Depth] A modular route to new antibiotics (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-05-20
    Description: Antibiotics have been taking it on the chin lately. Not only has resistance to the anti-infective medications been growing, but drug companies have been dropping antibiotic research programs, because the drugs are difficult and expensive to make. Now, new help is on the way. Researchers report this week that they've found a way to churn out new members of one of the most widely used classes of antibiotics. These drugs, called macrolides, were first developed in the 1950s and now represent a major bulwark against infections. A bevy of possible new drugs in this class could lead to new weapons against antibiotic-resistant infections, and possibly save millions of lives. Author: Robert F. Service
    Keywords: Organic Chemistry
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  • 57
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    [This Week in Science] Copper adds alkyls asymmetrically (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-04-22
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
    Print ISSN: 0036-8075
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 58
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    [This Week in Science] EZ catalyst control in olefin metathesis (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-04-29
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 59
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    [This Week in Science] Carbon links without helpful neighbors (2016)
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    In: Science
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    Publication Date: 2016-05-13
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 60
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    [Book Review] A monumental challenge (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-04-22
    Description: So prized by the ancient Romans were Egyptian obelisks that, at one time, more of them stood in Rome than in Egypt. In the 19th century, France, Britain, and the United States—inspired by Napoleon Bonaparte's expedition to Egypt in 1798— acquired their own major obelisks from Alexandria and Luxor. Cleopatra's Needles, by Egyptologist Bob Brier, explores the engineering challenges associated with building and erecting these massive monuments. Author: Andrew Robinson
    Keywords: Engineering
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  • 61
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    [Perspective] Rethinking the SN2 reaction (2016)
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    In: Science
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    Publication Date: 2016-04-01
    Description: The SN2 nucleophilic substitution reaction, X− + RY → XR + Y−, is a paradigm reaction in organic chemistry (1). The modern understanding of the SN2 reaction mechanism is based on work of Hughes and Ingold (2), who proposed that the nucleophile (X−) approaches the carbon atom that bears the leaving group (Y−). As a result, the bond between the carbon atom and the leaving group becomes weakened. As this bond breaks and a new bond forms between the nucleophile and the carbon atom, the configuration of the carbon atom is inverted. Analyses of gas-phase reaction rates led to the suggestion of a potential energy surface (PES) with two wells connected by a central barrier transition state (3). Electronic structure calculations have confirmed this picture for some SN2 reactions (4), but recent studies have shown that the actual reaction dynamics may be considerably more complex (see the figure) (5–8). Authors: Jing Xie, William L. Hase
    Keywords: Organic Chemistry
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  • 62
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    [This Week in Science] Beyond textbook SN2 chemistry (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-04-01
    Description: Author: Julia Fahrenkamp-Uppenbrink
    Keywords: Organic Chemistry
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  • 63
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    [This Week in Science] CO takes the lead to make β-lactam rings (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-11-18
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 64
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    [This Week in Science] Pluses and minuses of BTX behavior (2016)
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    In: Science
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    Publication Date: 2016-11-18
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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    [Book Review] Street smart (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-10-21
    Description: A physicist reveals the engineering marvels that underlie the modern metropolis Author: Sybil Derrible
    Keywords: Engineering
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  • 66
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    [This Week in Science] Catching a break in polyphenol synthesis (2016)
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    In: Science
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    Publication Date: 2016-12-09
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 67
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    [This Week in Science] How to turn olefins into nucleophiles (2016)
    American Association for the Advancement of Science (AAAS)
    In: Science
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    Publication Date: 2016-10-21
    Description: Author: Jake Yeston
    Keywords: Organic Chemistry
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    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 68
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    An overview of the present status of Water Quality of Lake Victoria, Kenya: a limnological perspective. (2015)
    Ministry of Environment and Natural Resources, LVEMP Water Quality Component | Kisumu, Kenya
    Details
    Publication Date: 2021-05-19
    Description: Sampling for nutrients, Chrolophyll-a and total suspended solids was done in 9 in-lake stations in the Kenyan part of Lake Victoria between December 2000 and October 2001. In-situ measurements of temperature, dissolved oxygen and water transparency were also carried out. PO4-P was found to range from 0.007mg/l to 0.057 mg/l and was higher in the pelagic stations than in littoral stations. NO3-N concentrations of 0.005-0.037 mg/l were recorded and were found to be relatively higher in the littoral stations than in the pelagic stations. TN:TP ration of the lake was found to be 6.78 indicating a possibility of heterocystous blue-green algae dominating. The ratio of 8.6 in the littoral stations showed a potential for higher photosynthetic rates in this part of the lake than in the pelagic zones. SRSi levels in the pelagic zones were found to have reduced significantly compared to those reported by Talling (1965), whereas those in the littoral zone was within the reported range. Water temperature was found to have increased and transparency values decreased compared to those measured by Worthington (1930) for both the open waters and within the gulf. Anoxic conditions (DO 〈1mg/l) were measured in depths of up to 30m.
    Description: Published
    Keywords: Water quality ; Limnology ; Nutrients (mineral)
    Repository Name: AquaDocs
    Type: Report , Not Known
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    Lake Victoria monitoring of the pelagic, littoral, river mouths and near shore urban environments, Kenya. (2015)
    Lake Victoria Environment Management Project (LVEMP) | Kisumu, Kanya
    Details
    Publication Date: 2021-05-19
    Description: The objectives of the Lake Victoria environment monitoring were to obtain data for: (1) Determination of the present state of the lake water quality and ecosystem. (2) Analysis of the relative importance of the biological processes and limiting factors in the eutrophication of the lake. (3) Calibration of the Lake Victoria Water Quality Framework Model. (4) Long -term monitoring of changes taking place in the lake. To achieve these objectives a programme for monthly lake monitoring on the lake was established to gather data on the quality of the waters of the lake and the lake’s limnology through in-situ measurements, and laboratory analysis of samples.
    Description: Published
    Keywords: Water quality ; Urbanization ; Eutrophication ; Limnology
    Repository Name: AquaDocs
    Type: Book Section , Not Known
    Format: pp.164- 212 [Chapter 8]
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    Eutrophication of Lake Victoria, Kenya: lessons for Water quality management. (2015)
    Lake Victoria Environment Management Project (LVEMP) | Kisumu, Kenya
    Details
    Publication Date: 2021-05-19
    Description: This paper reports on the major limnological and water quality findings in Lake Victoria, Kenya and offers suggestions on sustainable management of lake water quality.
    Description: Published
    Keywords: Water quality ; Eutrophication ; Resource management ; Limnology
    Repository Name: AquaDocs
    Type: Book Section , Not Known
    Format: pp.239-261 [Chapter 10]
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  • 71
    Electronic Resource
    Electronic Resource
    Masthead (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989) 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720101
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  • 72
    Electronic Resource
    Electronic Resource
    The Conformation of Cycloartenol Investigated by NMR and Molecular Mechanics (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 1-13 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cycloartenol (4), a natural plant sterol, was shown to be an effective membrane reinforcer; this was attributed to its conformation. We now present a conformational analysis of 4 by molecular modeling and NMR. Molecular modeling suggests that two conformations I and II coexist, differing mainly at the level of ring C, and of nearly equal energy, I and II each having ring A and B in a chair and half-chair conformation, respectively, with ring C 1,3-diplanar in I (solid-state structure as determined by X-ray crystallography) and in chair conformation in II. A complete assignment of the 1H- and 13C-NMR spectra of 4 and the entire coupling network in rings A and B is determined by various modern NMR techniques. The conformation of rings A and B thus determined is in agreement with conformations I and II. Low-temperature NMR experiments show a fast equilibrium between two conformations, presumably I and II. It is concluded, therefore, that the cyclopropane ring of 4 produces a flexibility at the level of ring C which may be important for the membrane properties.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720102
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  • 73
    Electronic Resource
    Electronic Resource
    Palladium(0)-Catalyzed Cyclizations of Simple 1-Aryl-1,7-octadien-3-yl Acetates. Preliminary communicationPresented (W.O.) at the ‘3e Congrès national de la Société Française de Chimie’, Nice, September 5, 1988. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 14-16 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dienyl acetates 2 lacking a geminal disulfone or a malonate group cyclize selectively to (E)-l-methylidene-2-styrylcyclopentanes 4 in the presence of 7 mol-% of [Pd(PPh3)4].
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720103
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  • 74
    Electronic Resource
    Electronic Resource
    Über den Einfluss des Akzeptor-Teilchromophors bei Dimethin-merocyanin-Farbstoffen auf das Aggregationsverhalten in wässriger Lösung (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 17-28 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the Influence of the Acceptor Part of the Chromophor of Dimethinemerocyanine Dyes upon the Aggregation Tendency in Aqueous SolutionA series of novel long-chain alkyl-dimethinemerocyanine dyes containing sulfonate groups is synthesized in good yield and their aggregation tendency in H2O and in organic solvent/H2O mixtures investigated. The merocyanine dyes 11 and 15 only exhibit an intense, red-shifted absorption band due to J-aggregation in H2O without addition of salt. The influence of cationic and anionic tensides and other compounds as urea, glucose, and polysaccharides upon the J-aggregation tendency is investigated.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720104
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  • 75
    Electronic Resource
    Electronic Resource
    Generation and Trapping of TriafulveneFulvene, Fulvalenes, Part 55; Part 54: [1].Short communication: [2]. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 29-40 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Substituted methylidenecyclopropanes 12a-d, being easily available from 1,1-dibromo-2-(phenylthio)-cyclopropane (9a), are attractive precursors of triafulvene (2-methylidene-1-cyclopropene; 1). Both the sulfoxide 12b and the sulfone 12c react with an excess of alkoxides (t-BuOK and NaOMe) to give 12e and 12f, respectively, while the sulfinyl group of 12b may be replaced by the PhCH2S substituent in the presence of PhCH2SH/t-BuOK. These reactions (Scheme 4) may be explained by assuming 1 as a reactive intermediate, although an alternative sequence including carbene 20 (Scheme 6) is not completely ruled out. D-labelling experiments (Scheme 5) do not give conclusive evidence due to D scrambling, but deprotonation/methylation sequences show that H—C(2) of 12a-c is the most acidic proton. Final evidence for 1 results from the reaction of 12d with cyclopentadienide (Scheme 7): the reaction of 1 with cyclopentadiene produces the expected [4 + 2]-cycloaddition product 23, while some mechanistic insight results from the sequence 12d → 24 → 25.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720105
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  • 76
    Electronic Resource
    Electronic Resource
    A Nonconcerted Intramolecular Diels-Alder Reaction of Chiral Allenic-Acid Derivatives (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 59-64 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction between the chiral allenic acid (+)-(S)-1 and the carbodiimides 2a-d and the keten-imine 6 gives, under mild conditions, the tricyclic compounds 3-5, 7, and 8. Low diastereoselectivity and a partial loss of optical activity are observed. A stepwise mechanistic pathway via a biradical intermediate is postulated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720108
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  • 77
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    Electronic Resource
    Konkurrenz von Endoperoxid- und Hydroperoxid-Bildung bei der Umsetzung von Singulett-Sauerstoff mit cyclischen, konjugierten Dienen. Teil I (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 51-58 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Competition of Endoperoxide and Hydroperoxide Formation in the Reaction of Singlet Oxygen with Cyclic, Conjugated DienesRose-bengal-sensitized photooxygenation of (-)-(R)-α-phellandrene (1) in MeOH at room temperature yielded a complex mixture of products, contrary to previous reports describing cis-(3S, 6R)-epidioxy-p-menthene (2) and trans-(3R, 6S)-epidioxy-p-menthene (3) as the only products. The mixture was separated by prep. HPLC (silica gel, pentane/Et2O 9:1). Besides the known endoperoxides 2 (yield 39%) and 3 (26%), all those hydroper-oxides, which can be deduced from an ene reaction of 1O2 with 1, were isolated, i.e. 4β-p-mentha-2,5-dien-1β-yl hydroperoxide (4) (14%), 4β-p-mentha-2,5-dien-1α-yl hydroperoxide (5) (9%), (2R, 4R)-p-mentha-1(7), 5-dien-2-yl hydroperoxide (6) (2,1%), (2S, 4R)-p-mentha-1(7),5-dien-2-yl hydroperoxide (7) (1,5%) and (1R)-p-mentha-3,6-dien-yl hydroperoxide (8; 1,5%; Scheme 1). Furthermore, the constant cis/trans ratio for all diastereoisomeric pairs (2/2, 4/2, 6/2) was striking. With the help of the two possible conformers 1a and 1b of the starting material a model of a common first step for endoperoxide as well as for hydroperoxide formation is developed. A photooxygenation at -50° supports this model. The absolute value of the cis/trans ratio changes in the same way for the endoperoxides and the hydroperoxides.
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    Versuche zur Synthese von Calicen aus trisubstituierten Cyclopropanen und Cyclopentenon56. Mitt. über Fulvene, Fulvalene; 55. Mitt. [1]: Kurzmitt. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 41-50 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Attempted Synthesis of Calicene from Trisubstitued Cyclopropanes and CyclopentenoneThe Li carbenoids 4, prepared by treatment of substituted 1,1-dihalocyclopropanes with BuLi, are reacted with cyclopent-2-enone under thermodynamic and kinetic control (Scheme 1). In general, the latter procedure gives better yields of cyclopropylcyclopentenols 5a-e, but the reaction seems to be controlled mainly by the steric and electronic properties of the substituent Y. So, with 4b and 4e, the main reaction is the attack of the carbenoid at C(1) of cyclopent-2-enone, while 4a (Y = PhS) predominantly deprotonates the ketone (Scheme 4). Whereas 5d and 5e can easily be converted to the dihydrocalicenes 6d and 6e (Scheme 6), the attempted elimination of H2O from 5a-c leads to the rearranged products 13-2 due to the opening of the cyclopropane ring (Scheme 5). Finally, the generation of the parent compound 2 from the silylated precursor 6d is attempted: treatment with MeO- gives the addition products 18A/18B, while the reaction with Br2 provides 19 by a bromination/dehydrobromination sequence (Scheme 7).
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  • 79
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    Locoselective [4 + 2] Cycloadditions of Vinylindoles with Inverse Electron Demand: A new access of indolyl-substituted and annellated pyridazinesDedicated to Prof. Dr. C. H. Brieskorn (Würzburg, FRG) on the occasion of his 75th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 65-72 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Vinylindole (1a) and its donor- and acceptor-substituted (E)-derivatives 1b-e react highly locoselectively with dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate (3) to form the novel (indol-2-yl)-1,4-dihydropyridazines 4a and 7 as well as the heterocyclic annellated pyridazines 4b, 5, and 6. The reactions of the structurally related 3-vinylindoles 2a-e with 3 also gave rise to new indol-3-ylpyridazines 8, 9, and 10. The locoselectivities of these Diels-Alder reactions were controlled mainly by steric effects.
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  • 80
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    Photochemistry of Thiophen-2(5H)-onesDedicated to Prof. Dr. O. E. Polansky on the occasion of his 70th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 83-92 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mechanistic evidence for the light-induced ring opening of thiophen-2(5H)-ones 1 in alcohols affording α, β-unsaturated mercapto esters 2 is presented. Regio-and stereochemical aspects of the ring closure of alkenylthio (type 3) radicals 15 and 17 to S-heterocycles 16 and 18, of 3-thiahex-5-enyl radicals 4 to (tetrahydrothien-3-yl)methyl radicals 6 and of (2,3-dihydrothien-3-yl)methyl radicals 30 (type 7, but-3-enyl radicals) to cyclopropane-methyl radicals 29 are discussed. Irradiation (λ 350 nm) of 1 in cyclohexane in the presence of 2,3-dimethylbut-2-ene affords [2 + 2] cycloadducts 14 albeit in very low yields.
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  • 81
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    Electronic and Molecular Structure of the C8H10+· Valence Isomers 1,3,5-Cyclooctatriene+· and Bicyclo[4.2.0]octa-2,4-diene+· from their Electronic absorption Spectra in Freon (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 73-82 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The molecular cations of 1,3,5-cyclooctatriene (COT+·) and bicyclo[4.2.0]octa-2,4-diene (BCO+·) can be observed intact in γ-irradiated Freon glasses, as opposed to Ar matrices where ionization is accompanied by extensive rearrangements. This proves the superiority of the Freon-glass method for the generation of metastable primary cations. The electronic absorption (EA) spectra reveal a) that a previous analysis of the BCO+· electronic structure on the basis of the ultraviolet photoelectron (UP( spectrum of BCO was incomplete, and b) that COT undergoes planarization upon ionization, in accord with qualitative expectations and MNDO calculations. A previously proposed LCBO model was used to assess the influence of the above geometry change on the electronic structure of COT+·.
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  • 82
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    Cyclization Studies with N-Mannich bases of 2-substituted indoles (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 93-100 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of the indoles 7, 15, 16 with a 3-methoxyphenyl group, attached via an α-side chain of 1,2,or 3 CH2 units, is reported. These compounds, after appropriate protection at C(3), were transformed into the N-[(dimethylamino)methyl]indoles 22, 23, and 24, respectively. When treated with AcCl, these N-Mannich bases gave, in two cases, stable N-(chloromethyl)indoles 25 and 26. In the presence of SnCl4, ring closure occurred via electrophilic attack of 1-methylideneindolium ions on the methoxyphenyl group. Formation of seven-membered rings (→ 27, 28) and eight-membered rings (→ 29) was found to be a favorable process. Cyclization to six-membered rings did not occur within this series.
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  • 83
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    Template-Dependent Incorporation of Spin-Labeled Thymidine Analogs into Viral DNA (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 110-116 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of novel pppUd analogs substituted at position C(5) with tethered nitroxide radicals is reported. It is shown that these analogs can serve as good substrates for E. coli DNA polymerase (Pol I) and T-4 DNA polymerase using lambda-phage DNA as template. The template-dependent incorporation of the substrates was established by radio-labeling and ESR experiments.
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  • 84
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    Stereoselektive Synthesen von Taxan-Derivaten (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 101-109 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Stereoselective Synthesis of Taxane DerivativesSubstituted racemic 4,8,12-trinortaxanes were prepared stereoselectively in several steps from the dienone 10. A variant of the de Mayo reaction with bicyclononenones 4 and cyclohexen produced the desired configuration at C(8) of the taxane framework. Retro-aldol cleavage of the tetracycle 5 led to the taxane skeleton 6. Stereoselective reduction followed by treatment with base afforded 7b. Hydrolysis of the acetal group and further reduction yielded 9 in which the relative configuration corresponds to the one of the natural products.
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  • 85
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    Asymmetric Diels-Alder reactions: X-Ray crystal-structure analysis of [N-((E)-But-2-enoyl)bornane-10,2-sultam]tetrachlorotitaniumPresented (WO) at the Annual Congress of the Royal Society of Chemistry, Canterbury, April, 1988. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 123-130 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An X-ray diffraction analysis of the crystalline complex 2b (MLn — TiCl4) shows a chelation of the carbonyl O-atom and the upper SO2 O-atom by TiCl4, a slightly pyramidal N-atom, and a π -face-stereoselective shielding of the C(α)-Si face by the CH2(3) group. The Ti-atom is in a pseudo-octahedral environment.
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  • 86
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    Metal Complexes with Macrocyclic Ligands. Part XXVIIPart XXVI. Cu2+-promoted hydrolysis of carboxylic- and phosphonic-acid esters in the side chain of tetraazamacrocycles (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 131-138 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The X-ray structures of the Cu2+ complexes of 1,4,8,11-tetraazacyclotetradecane derivatives with an ethylpro-pionate and diethylphosphonate group, 5 and 6, respectively, indicate that the metal ion is pentacoordinated by the four N-atoms of the macrocycle and one O-atom. In the case of 5, it is the carbonyl O-atom of the carboxylate group, whereas for 6 it is the phosphonyl O-atom of the phosphonate group. The hydrolysis kinetics of the functional group in the Cu2+ complexes with the 1,4,8,11-tetraazacyclotetradecanes 3-6 have been measured by pH-stat and stopped-flow techniques. The rate law for the hydrolysis of the carboxylates 3-5 is proportional to the complex concentration and to [OH-] up to pH 13, whereas that of the phosphonate 6 is proportional to [OH-] up to pH 11.5, becoming independent of [OH-] at pH 〉 11.5. The mechanisms of these two reactions are discussed, considering the possibility of an intra- or an intermolecular OH- attack and the results of the X-ray structure analyses.
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  • 87
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    A New Method for the Preparation of (E)-3-Acylprop-2-enoic AcidsPresented in part at the autumn meeting of the Swiss Chemical Society in Bern on October 21, 1988.Dedicated to Prof. R. E. Ireland on the occasion of his 60th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 117-122 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new method for the preparation of (E)-3-acylprop-2-enoic acids ( = (E)-3-acylacrylic acids) of type II via acid-catalyzed isomerization of the corresponding 3-acylprop-2-ynal acetals of type I (Scheme 1) has been found. The described reaction gives a rapid and quite general access to these compounds known to exhibit a number of interesting biological activities. Some studies toward the elucidation of the reaction mechanism have been made, and a hypothetical mechanism is proposed.
    Additional Material: 2 Tab.
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  • 88
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    6-Thia-1-aza-5λ5-phosphabicyclo[3.2.0]hept-3-ene und Isothiocyanatophosphin-sulfide aus (Methylidenamino)phosphinen, Schwefelkohlenstoff und Acetylen- oder Ethylen-Derivaten (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 139-146 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 6-Thia-l-aza-5λ5-phosphabicyclo[3.2.0]hept-3-enes and Isothiocyanatophosphine-sulfides from (Methylidenamino)phosphines, Carbon Disulfide, and Acetylene- or Ethylene Derivatives(Methylidenamino)phosphines react with carbon disulfide to 1,3,2-thiazaphosphete derivatives 2. Acetylenedicarboxylates give with 2 6-thia-l-aza-5λ5-phosphabicyclo[3.2.0]hept-3-enes 4a, b, and acrylates yield isothio-cyanatophosphin-sulfides 5a-c. The structures of 4a and 5a are proven by an X-ray diffraction analysis.
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  • 89
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    C45 und C50-Carotinoide. 6. Mitteilung5. Mitteilung, s. [1]. Synthese eines optisch aktiven cyclischen C20-Bausteins und von Decaprenoxanthin (= (2R, 6R, 2′R, 6′R)-2,2′-Bis(4-hydroxy-3-methylbut-2-enyl)-∊, ∊-carotin) (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 151-157 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: C45- and C50-Carotenoids: Synthesis of an Optically Active Cyclic C20-Building Block and of Decaprenoxanthin ( = (2R, 6R, 2′R, 6′R)-2,2′-Bis(4-hydroxy-3-methylbut-2-enyl)-∊, ∊-carotene)The synthesis of the optically active cyclic C20-building block (R, R)-15 and of the optically active C50-carotenoid (2R, 6R, 2′R, 6′R)-decaprenoxanthin (1) starting from (-)-β-pinene ((S)-2) is reported.
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  • 90
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    Formation of the First Trimeric Monoterpenoid Indole Alkaloids (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 147-150 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Under O2, the Aspidosperma alkaloid tabersonine (1) was converted by a crude enzyme preparation from leaves of mature plants of Catharanthus roseus G DON into the trimeric 3-hydroxy-14′-(3α″-tabersonyl)voafrine B (4) which was easily reduced by NaBH4 to 14′-(3α″-tabersonyl)voafrine B ( = tertabersonine; 5). Compounds such as 4 and 5 are the first trimeric alkaloids in the series of monoterpenoid indole alkaloids.
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    URL: http://dx.doi.org/10.1002/hlca.19890720119
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  • 91
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    Polynuclear Iron and Rhodium Complexes of 7-Oxa[2.2.1]hericene (2,3,5,6-tetramethylidenebicyclo[2.2.1]heptan-7-one) (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 158-164 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: μ-Carbonyl(Rh—Rh)di(η5-indenyl)[(2R,3S)-C,2,3,C-η-(2,3,4,5-tetramethylidenebicyclo[2.2.1]heptan-7-one)]]-dirhodium(I)(Rh—Rh) (7) and cis-μ-[(2R,3S,5R,6S))-C,2,3,C-η:C,5,6,C-η-(2,3,5,6-tetramethylidenebicyclo[2.2.1]heptan-7-one)]bis[μ-carbonyldi(η5-indenyl)dirhodium(I)(Rh—Rh)] (8) have been prepared. Complex 7 reacts with Fe2(CO)9 in hexane/MeOH and gives cis-μ-[(2R,3S,5R,6S] (9), trans-μ-[(2R,3S,5S,6R)-C,2,3,C-η: C,5,6, C-η-(2,3,5,6-tetramethylidenebicyclo[2.2.1]heptan-7-one)-μ-carbonyldi(η5-indenyl)dirhodium(I)(Rh—Rh)-(tricarbonyliron) (10), and, μ-carbonyl(Rh—Rh)[(2R,3S)-C,2,3,C-η-(2,3-dimethyl-5,6-dimethylidenebicyclo-[2.2.1]hept-2-en-7-one)]di(η5-indenyl)dirhodium(I)(Rh—Rh) (11). Treatment of 7-oxa[2.2.1]hericene (4) with Fe2(CO)9 or (cyclooctene)2Fe(CO)3 gave a 1:2 mixture of cis-μ-[(2R,3S,5R,6S)-] (12) and trans-μ-[(2R,3S,5S,6R)-C,2,3,C-η:C,5,6,C-η-(2,3,5,6-tetramethylidenebicyclo[2.2.1]heptan-7-one)]bis(tricarbonyliron)(13).
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    Eine neue Aminoazirin-Reaktion. Bildung von 3,6-Dihydropyrazin-2(1H)-onen (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 172-179 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A New Aminoazirine Reaction. Formation of 3,6-Dihydropyrazin-2(1H)-onesThe reaction of 3-(dimethylamino)-2H-azirines 1 and 2-(trifluoromethyl)-1,3-oxazol-5(2H)-ones 5 in MeCN or THF at 50-80° leads to 5-(dimethylamino)-3,6-dihydropyrazin-2(1H)-ones 6 (Scheme 3). Reaction mechanisms for the formation of 6 are discussed: either the oxazolones 5 react as CH-acidic heterocycles with 1 (Scheme 4), or the azirines 1 undergo a nucleophilic attack onto the carbonyl group of 5 (Scheme 6). The reaction via intermediate formation of N-(trifluoroacetyl)dipeptide amide 8 (Scheme 5) is excluded.
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    Synthesis of the Oviposition-Deterring Pheromone (ODP) in Rhagoletis cerasi L. Preliminary communication (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 165-171 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For the assignment of the configuration at C(8) and C(15) of the natural oviposition-deterring pheromone 1 in Rhagoletis cerasi L., the four possible stereoisomers of 1 are synthesized. By condensing the C6 building blocks (5R)-4 and (5S)-4 with the boron enolates of the C10 building blocks (4S)-13 and (4R)-13, followed by decarboxylative dehydration, all stereoisomers of 16 are available (Scheme 5). Glucosylation of 16 followed by formation of the taurin amide gives, after deprotection, the four stereoisomers (8R,15S)-1, (8R,15R)-1, (8R,15S)-1, and (8S,15S)-1 (Scheme 6).
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    Mitteilungen (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 185-192 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    URL: http://dx.doi.org/10.1002/hlca.19890720125
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    New Spermine Alkaloids from Aphelandra tetragona (VAHL) NEESDedicated to Prof. Dr. D. Gröger on the occasion of his 60th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 180-184 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 18-O-Methylchaenorpine (1a) and iso-18-O-methylchaenorpine (1b) two novel stereoisomeric spermine alkaloids were isolated from the roots of Aphelandra tetragona (VAHL) NEES. Their structures were established by chemical and spectroscopic studies.
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  • 96
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    Masthead (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989) 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    URL: http://dx.doi.org/10.1002/hlca.19890720201
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    1,5,7-Triazabicyclo[4.4.0]dec-5-en als Reaktionsmedium: Präparativ ergiebige einstufige Herstellung von Etioporphyrin aus Protoporphyrin (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 185-195 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,5,7-Triazabicyclo[4.4.0]dec-5-ene as Reaction Medium: An Efficient One-Step Formation of Etioporphyrine from ProtoporphyrineHeating the commercially available protoporphyrine (4) in molten 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) at 200° for 4 h under exclusion of O2 produces etioporphyrine (6) in 60-70% yield by bisdecarboxylation and concomitant reduction of the two vinyl groups. Mesoporphyrine (5) is bisdecarboxylated to 6 in over 80% yield under these conditions in TBD as well as in DBU as the reaction medium.
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    URL: http://dx.doi.org/10.1002/hlca.19890720202
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  • 98
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    The Chemistry of Thujone. Part XIV.Part XIII [1]. Synthesis of biologically active aryl terpenoid analogues (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 205-212 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Employing thujone-derived intermediates, a series of achiral (9a-d; Scheme 1) and chiral (11b and 11d; Scheme 2) terpene analogues related to the biologically active ‘terpenoid’ hybrids have been prepared. The stereochemistry of the key epoxidation reaction was established by correlation of the product 11b with the previously reported alcohol (R)-20 of known absolute configuration (Scheme 3).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720204
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  • 99
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    Vinyl Carbanions. Part 36.Part 35: [9]. Synthesis of 3-deoxy-D-manno-2-octulosonic acid (KDO) and derivatives (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 213-223 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The β-C-lithiated acrylamide 3A has been proven to be an ideal pyruvate β-carbanion equivalent useful in a highly diastereoselective KDO synthesis. The starting material 3 was prepared from pyruvate diethyl acetal in four convenient steps. Direct lithiation with 2 equiv. of LDA generated the dilithiated species 3A quantitatively. Reaction with 2,3:4,5-di-O-isopropylidene-D-arabinose (11) was highly D-manno-selective. The product 12 was obtained readily from the reaction mixture via crystallization. Ring closure to the butenolide 13, subsequent PhS-group removal with Bu3SnH and pyridinium bromide, and hydrogenolytic debenzylation afforded the known butenolide 19; this KDO precursor gives KDO in two convenient steps. Butenolide 19 was also transformed via two high-yielding steps into the 4,5:7,8-di-O-cyclohexylidene-KDO derivative 22, a valuable starting material for KDO α-glycoside syntheses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720205
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  • 100
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    Colchicine models: Synthesis and Antitubulin Activity of 2′-Monosubstituted and 2′, 5-Disubstituted 2,3,4,4′-Tetramethoxy-1,1′-biphenyls. Synthesis of 4,4′, 5′, 6′-tetramethoxy-1,1′-biphenyl-2,3′-dicarboxylic acidThis paper is dedicated to our friend and colleague Dr. Tetsuji Kametani, Hoshi College of Pharmacy, Tokyo, Japan, who died on October 11, 1988 (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 196-204 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reductive amination of 2,3,4,4′-tetramethoxtybiphenyl-2-carbaldehyde (4) with MeNH2 afforded methylamine 5 (Scheme 1), Hydroxymethylation of amine 8, prepared similarly from 4 by reductive amination with benzylamine followed by N-methylation, afforded alcohol 12 which was converted the 5-methyl-substituted methylamine 14 by conventional chemical reactions (Scheme 2), Methylamine 14 was also obtained from ester 16 after hydroxymethylation to alcohol 17 and conventional manipulation of alcohol and ester functions (Scheme 2). Both amines 5 and 14 as well as the 2′, 5-dimethyl-substituted biphenyl 26 prepared from the dialdehyde 25 by a Wolff-Kishner reduction, did not show noteworthy activity in the tubulin binding assay or as inhibitors of tubulin polymerization (Table). However, the 2′ethyl-substituted biphebyl 11 prepared from 4 by reaction with MeLi followed by dehyderation and catalytic reduction of styrene 10 (Scheme 1) showed appreciable activity in both assays, coming close to that of known phenyltropolone models. The X-ray analysis of 14·HCl and 11 showed significant difference in the orientation of the rings with respect to one another (Fig.).
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    URL: http://dx.doi.org/10.1002/hlca.19890720203
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