ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Animals  (106)
  • Chemical Engineering  (67)
  • Humans  (58)
  • Life and Medical Sciences  (54)
  • COMMUNICATIONS AND RADAR
  • FLUID MECHANICS AND HEAT TRANSFER
  • STRUCTURAL MECHANICS
  • 1990-1994
  • 1980-1984  (351)
  • 1981  (351)
Collection
Keywords
Years
  • 1990-1994
  • 1980-1984  (351)
Year
  • 1
    ISSN: 0197-8462
    Keywords: millimeter-wave radiation ; BHK-21/C13 cells in monolayer culture ; scanning electron microscopy ; transmission electron microscopy ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Both thermal and athermal effects of millimeter-wave radiation on BHK-21/C13 cells were sought using scanning and transmission electron microscopy in conjunction with an in vitro technique that allows direct exposure of monolayer cultures to high average power densities. Culture dishes were irradiated by placing them on the open end of an E- or U-band wave guide. This technique exposes different regions of the cell monolayer lying along the longer axis of the wave guide aperture to varying power densities ranging from zero at each edge to twice the average power density at the center.Cell ultrastructure was unaffected by microwave radiation for 1 hour (41.8 or 74.0 GHz, average power densitites = 320 or 450 mW/cm2, respectively) with or without cooling by rapid recirculation of the culture medium. Temperature in recirculated cultures was held at 37.2 °C, and that in noncooled cultures never exceeded 42 °C during irradiation at either power density. In contrast, cell morphology was affected by microwave exposure whenever irradiation conditions were altered so that the temperature of the monolayer reached or exceeded 44.5 °C. Ultrastructural alterations included breakage of cell processes, progressive detachment of cells from the substrate, increased clumping of heterochromatin in the nuclei, and the appearance of large empty vesicles in the cytoplasm. Such morphological changes resulted from either application of higher average power densities or irradiation at the power densities described above at a higher ambient temperature (〉38.5°C).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0197-8462
    Keywords: millimeter-wave radiation ; BHK-21/C13 cells in monolayer culture ; quantitative autoradiography ; ribonucleic acid (RNA) synthesis ; protein synthesis ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: A method has been devised whereby both the thermal and possible athermal biological effects resulting from microwave radiation can be assessed. Monolayer cultures of BHK-21/C13 cells were grown on microwave-transparent polystyrene coverslips, placed directly on the open end of a wave guide, and irradiated for 1 hour. In experiments seeking athermal biological effects of millimeter waves, culture medium was continuously recirculated over the cells to prevent temperature increases greater than 0.1 °C. Incorporation of 3H-uridine into RNA and of 3H-methionine into protein was quantified by measurement of optical densities of the autoradiographs in contiguous rectangular regions corresponding to portions of the cell monolayer immediately above the wave guide aperture and lying along its longer axis. Since power density was shown to vary with position along this axis according to a cosine2 relationship, it was possible to assess the extent of microwave effects on macromolecular synthesis at power densities ranging from zero at each edge to twice the average power density at the center of the waveguide.Monolayer cultures maintained at 37.2 °C by recirculation of the medium did not show microwave-induced changes in synthesis of RNA and protein (41.8 or 74.0 GHz at average power densities of 320 or 450 mW/cm2, respectively). Since macromolecular synthesis was examined both during and after irradiation, our results exclude both transient and persistent athermal biological effects of acute exposure to millimeter waves. In contrast, irradiation of cultures incubated in a small volume of nonrecirculated medium resulted in 1) marked heating of the monolayer, 2) a graded decline in macromolecular synthesis with increasing incident power, and 3), in some cases, destruction of the cell monolayer in the region immediately above the center of the waveguide aperture.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0197-8462
    Keywords: protein synthesis ; quantitative autoradiography ; BHK-21/C13 cells ; millimeter-wave radiation ; frequency-specific biological effects ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: A method recently developed in this laboratory has been used to directly expose BHK-21/C13 cells to high levels of microwave radiation without significant microwave-induced heating (≤ 0.1 °C). Monolayer cultures were grown on microwave-transparent polystyrene coverslips, placed on the open end of a wave guide, and maintained at 37.2 °C during irradiation at frequencies in both the E- and U-bands (average power densities 292 and 177 mW/cm2, respectively). Effects of microwave radiation were assessed at 0.1 GHz increments in the ranges of 38-48 GHz and 65-75 GHz. Protein synthesis was measured in quadruplicate cultures that were allowed to incorporate labeled methionine during the 15-minute period of microwave irradiation. Autoradiographs of each monolayer culture were scanned along the region corresponding to the longer axis of the wave guide aperture using a microdensitometer to quantify incorporation. Since microwave power incident on the cells was previously shown to vary along this axis according to a cosine2 relationship from zero at each edge of the wave guide to twice the average power density at the center of the wave guide, this technique should reveal biological effects that might only be manifested in narrow amplitude domains or “power windows.” Observations of protein synthesis in monolayer cultures irradiated at 202 closely spaced frequencies in the E- and U-bands failed to reveal changes associated with microwave exposure. Thus no evidence was obtained in support of the existence of frequency-specific athermal biological effects of microwaves. In addition, no support was found for the existence of amplitude-specific “power windows”.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 1981-05-22
    Description: Extracts of samples of a Caribbean tunicate (ascidian, sea squirt) of the family Didemnidae inhibit in vitro at low concentrations the growth of DNA and RNA viruses as well as L1210 leukemic cells. The active compounds isolated from the tunicate, didemnins A, B, and C, are depsipeptides, and didemnin B (a derivative of didemnin A) is the component active at the lowest concentration in inhibiting viral replication in vitro and P388 leukemia in vivo.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Rinehart, K L Jr -- Gloer, J B -- Hughes, R G Jr -- Renis, H E -- McGovren, J P -- Swynenberg, E B -- Stringfellow, D A -- Kuentzel, S L -- Li, L H -- AI 04769/AI/NIAID NIH HHS/ -- GM 27029/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1981 May 22;212(4497):933-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7233187" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Antibiotics, Antineoplastic/*isolation & purification ; Antiviral Agents/*isolation & purification ; *Depsipeptides ; Leukemia, Experimental/*drug therapy ; Peptides, Cyclic/*isolation & purification/therapeutic use ; Structure-Activity Relationship ; Urochordata/*analysis
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 1981-08-21
    Description: Sunlight photodegradation of 2,2', 4,4', 5,5' -hexabromobiphenyl, the major component of Firemaster, gave a mixture that produces severe hyperkeratosis of the rabbit ear. This component in its pure state does not cause hyperkeratosis. One or more of the four major photolysis products must be responsible for this activity. A similar photodegradation pattern was observed for 2,2', 3,4,4', 5,5' -heptabromobiphenyl, the second largest component of Firemaster.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Patterson, D G -- Hill, R H -- Needham, L L -- Orti, D L -- Kimbrough, R D -- Liddle, J A -- New York, N.Y. -- Science. 1981 Aug 21;213(4510):901-2.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6266016" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Biphenyl Compounds/radiation effects ; Chemical Industry ; Disease Models, Animal ; Environmental Exposure ; Keratosis/*chemically induced ; Michigan ; Photochemistry ; *Polybrominated Biphenyls/radiation effects ; Rabbits ; Sunlight
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 1981-06-12
    Description: Somatomedin-C stimulates somatostatin release to a maximum of 390 percent of basal release during short-term (20-minute) incubation of rat hypothalamus. It has no effect on basal or stimulated growth hormone release from primary cultures of rat adenohypophyseal cells during a 4-hour incubation, but inhibits stimulated release by more that 90 percent after 24 hours. These findings suggest that somatomedin-C participates in the growth hormone negative feedback loop with an immediate effect on hypothalamic somatostatin and a delayed effect on the anterior pituitary.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Berelowitz, M -- Szabo, M -- Frohman, L A -- Firestone, S -- Chu, L -- Hintz, R L -- AM 18722/AM/NIADDK NIH HHS/ -- AM 24085/AM/NIADDK NIH HHS/ -- New York, N.Y. -- Science. 1981 Jun 12;212(4500):1279-81.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6262917" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Bucladesine/pharmacology ; Cells, Cultured ; Dose-Response Relationship, Drug ; Feedback ; Growth Hormone/pharmacology/*secretion ; Hypothalamus/drug effects/*physiology ; Insulin-Like Growth Factor I ; Kinetics ; Pituitary Gland, Anterior/drug effects/*secretion ; Rats ; Somatomedins/*pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 1981-12-04
    Description: The guanosine analog 8-aminoguanosine is an effective inhibitor of the purine degradative enzyme purine nucleoside phosphorylase, both in vitro and in intact lymphoid cells. In a human lymphoblast tissue culture system, 8-aminoguanosine, in combination with low concentrations of 2'-deoxyguanosine, causes toxicity toward T cells but not B cells. The selective T cell toxicity correlates with increased accumulation of deoxyguanosine triphosphate in the treated T lymphoblasts.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kazmers, I S -- Mitchell, B S -- Dadonna, P E -- Wotring, L L -- Townsend, L B -- Kelley, W N -- AM 19045/AM/NIADDK NIH HHS/ -- CA 26032/CA/NCI NIH HHS/ -- CA 26284/CA/NCI NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1981 Dec 4;214(4525):1137-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6795718" target="_blank"〉PubMed〈/a〉
    Keywords: B-Lymphocytes/enzymology ; Cell Line ; Deoxyguanosine/pharmacology ; Guanosine/*analogs & derivatives/pharmacology ; Humans ; Kinetics ; Pentosyltransferases/*antagonists & inhibitors ; Purine-Nucleoside Phosphorylase/*antagonists & inhibitors ; T-Lymphocytes/drug effects/*enzymology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 1981-08-28
    Description: Benzoyl peroxide, a widely used free radical-generating compound, promoted both papillomas and carcinomas when it was topically applied to mice after 7,12-dimethylbenz[a]anthracene initiation. Benzoyl peroxide was inactive on the skin as a complete carcinogen or as a tumor initiator. A single topical application of benzoyl peroxide produced a marked epidermal hyperplasia and induced a large number of dark basal keratinocytes, effects similar to those produced by the potent tumor promoter 12-O-tetradecanoyl phorbol-13-acetate. Benzoyl peroxide, like other known tumor promoters, also inhibited metabolic cooperation (intercellular communication) in Chinese hamster cells. In view of these results caution should be recommended in the use of this and other free radical-generating compounds.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Slaga, T J -- Klein-Szanto, A J -- Triplett, L L -- Yotti, L P -- Trosko, K E -- CA 21104/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1981 Aug 28;213(4511):1023-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/6791284" target="_blank"〉PubMed〈/a〉
    Keywords: 9,10-Dimethyl-1,2-benzanthracene ; Animals ; *Benzoyl Peroxide ; *Cocarcinogenesis ; Free Radicals ; Mice ; Neoplasms, Experimental ; *Peroxides ; Skin Neoplasms/*chemically induced ; Tetradecanoylphorbol Acetate
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2019-06-28
    Description: Candidate data communication techniques are identified, including dedicated links, local buses, broadcast buses, multiplex buses, and mesh networks. The design methodology for mesh networks is then discussed, including network topology and node architecture. Several concepts of power distribution are reviewed, including current limiting and mesh networks for power. The technology issues of packaging, transmission media, and lightning are addressed, and, finally, the analysis tools developed to aid in the communication design process are described. There are special tools to analyze the reliability and connectivity of networks and more general reliability analysis tools for all types of systems.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NASA-CR-165773 , NAS 1.26:165773 , R-1469-VOL-1
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2019-06-28
    Description: The application of communication structures to advanced transport aircraft are addressed. First, a set of avionic functional requirements is established, and a baseline set of avionics equipment is defined that will meet the requirements. Three alternative configurations for this equipment are then identified that represent the evolution toward more dispersed systems. Candidate communication structures are proposed for each system configuration, and these are compared using trade off analyses; these analyses emphasize reliability but also address complexity. Multiplex buses are recognized as the likely near term choice with mesh networks being desirable for advanced, highly dispersed systems.
    Keywords: COMMUNICATIONS AND RADAR
    Type: NASA-CR-165774 , NAS 1.26:165774 , R-1469-VOL-2
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...