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  • 1
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 28 (1994), S. 1259-1266 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Two new polymeric materials (polymers A and B) containing covalently bound iodine were prepared. These polymers were evaluated with respect to their possible use as radiopaque implant biomaterials - that is, materials that are visible in a noninvasive manner using routine X-ray absorption imaging techniques. Polymer A is a copolymer of methyl methacrylate (MMA) and 1 (80 and 20 mol%, respectively). Polymer B was prepared from MMA, 1, and 2-hydroxyethyl methacrylate (HEMA) (mol ratio 65:20:15, respectively). Compound 1 was synthesized from 4-io-dophenol and methacryloyl chloride. The resulting polymers were characterized with GPC, DSC, NMR, and by measuring both the advancing and receding contact angles. Thrombogenicity of the polymers was determined by an in vitro thrombin generation test procedure. The maximum concentration of free thrombin was 76 ± 1 nM for polymer A, and 64 ± 3 nM for polymer B. The lag times (i.e., time onset of thrombin generation) were 392 seconds for polymer A and 553 seconds for polymer B. For PVC-T, which is known as a passive material, a lag time of 583 seconds was found. This indicates that polymer B is comparable to PVCT, and more passive than polymer A. Polymer A exhibited minor activation of platelets. Polymer B did not induce platelet activation at all. The polymers exhibited, even as fibers with a diameter of ca. 0.3 mm, good radiopacity with routine imaging X-ray techniques in the clinic. It is argued that polymers A and B - which actually represent a whole family of radiopaque polymeric biomaterials - exhibit promising properties with respect to applications as construction materials for a new generation of endovascular stents. © 1994 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: A methacrylic monomer containing three iodine atoms, 2-[2′,3′,5′-triiodobenzoyl]-ethyl methacrylate (compound 1), was prepared in pure form. Compound 1 can be reacted with other methacrylates, such as methyl methacrylate (MMA), and 2-hydroxyethyl methacrylate (HEMA) with high conversion. Typically, less than 0.5% of free monomer is left after polymerization. For example, compound 1 was reacted with MMA and HEMA in the molar ratio 7:73:20, respectively. This yielded a terpolymer with Tg = 86°C, Mw = 47,000 g/mol and Mn = 22,800 g/mol. This material was characterized by various physicochemical techniques, including gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, and nuclear magnetic resonance (NMR) spectroscopy (1H at 400 MHz, DMSO-d6 solution). In addition the material was found to exhibit low surface thrombogenicity in vitro and a low propensity to activate contacting blood platelets. Furthermore it was found that the terpolymer is markedly radiopaque: even thin objects (〈0.5 mm) could be easily visualized using X-ray fluoroscopic techniques as are routinely used in the clinic, e.g., during coronary angiography. The combined results obtained with the present terpolymer (particularly its in vitro hemocompatibility and its radiopacity) leads to the suggestion that this type of polymer could be used as cardiovascular biomaterials, for instance for the construction of a new type of endovascular stents. These would be expected to show improved biocompatibility if compared with metallic stents which are currently used, for instance in conjunction with percutaneous transluminal coronary angioplasty (PTCA). A stent prototype, constructed from the present radiopaque terpolymer, is shown and discussed briefly. © 1996 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
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  • 3
    Publication Date: 2020-07-02
    Description: The use of deinking paper sludge (DPS) as a fertilizer instead of sending it to landfill could play a role in reducing greenhouse gases and improving soil properties. The objectives of this study were (1) to evaluate the changes in the physical (permeability and structural stability), chemical (particularly soil pH), and biological (microbial metabolic quotient (qCO2), microbial biomass soil CO2 emissions) of a calcareous agricultural soil following two successive annual amendments with three treatments (0, 30, and 60 Mg DPS ha−1—control, DPS30, and DPS60, respectively); and (2) to determine whether the addition of N-fertilizer to these treatments (controlF, DPS30F, and DPS60F, respectively) causes changes to soil fertility. The DPS application increased soil organic matter (+0.80%: DPS60 vs. control; and +0.35%: controlF vs. DPS60F), available phosphorus (+23.14 mg kg−1: DPS60 vs. control; and +14.34 mg kg−1: DPS60F vs. controlF), potassium (+0.6 g kg−1: controlF vs. DPS30F), and calcium (+0.28 g kg−1: DPS60 vs. control). The 60 Mg DPS ha−1 rate improved permeability and structural stability, regardless of the presence or absence of N-fertilizer. On the other hand, the 60 Mg DPS ha−1 rate without N-fertilizer lead to a decrease in total mineralization rate and qCO2, thereby indicating a reduction in CO2 emissions. The rate of 60 Mg ha−1 DPS could be effectively used to enhance the permeability and stability (soil restoration) and mitigate CO2 emissions, whereas the 30 Mg ha−1 rate could be used as fertilizer to improve the fertility of calcareous soils.
    Electronic ISSN: 2073-4395
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Economics
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  • 4
    Publication Date: 2018-06-15
    Description: In the present work, the treatment of a leachate from Fez city urban sanitary landfill (Morocco) was evaluated using different advanced oxidation processes (AOPs), such as, Fenton (Fe 2+ /H 2 O 2 ), photo-Fenton (Fe 2+ /H 2 O 2 /UV-A), UV-A and UV-A/H 2 O 2 . The leachate was characterized by high chemical oxygen demand (COD), low biodegradability and intense dark color. The treatment efficiency was evaluated as a function of different operation variables ([H 2 O 2 ], [Fe 2+ ], UV-A irradiance), resulting in COD removals between 30% and 77%. Removal efficiencies decreased in the following order: photo-Fenton〉 Fenton〉 UV-A/H 2 O 2 〉 UV-A. Thus, a detailed experimental analysis was carried out to analyze the effect of hydrogen peroxide and iron concentration in the photo-Fenton process. It was observed that: (a) COD removal ranged from 4% to 84% depending o...
    Print ISSN: 1755-1307
    Electronic ISSN: 1755-1315
    Topics: Geography , Geosciences , Physics
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  • 5
    Publication Date: 2020-11-06
    Description: Serum prostate-specific antigen (sPSA) testing has helped to increase early detection of and decrease mortality from prostate cancer. However, since sPSA lacks specificity, an invasive prostate tissue biopsy is required to confirm cancer diagnosis. Using urinary extracellular vesicles (EVs) as a minimally invasive biomarker source, our goal was to develop a biomarker panel able to distinguish prostate cancer from benign conditions with high accuracy. We enrolled 56 patients in our study, 28 negative and 28 positive for cancer based on tissue biopsy results. Using our Vn96 peptide affinity method, we isolated EVs from post-digital rectal exam urines and used quantitative polymerase chain reaction to measure several mRNA and miRNA targets. We identified a panel of seven mRNA biomarkers whose expression ratio discriminated non-cancer from cancer with an area under the curve (AUC) of 0.825, sensitivity of 75% and specificity of 84%. We also identified two miRNAs whose combined score yielded an AUC of 0.744. A model pairing the seven mRNA and two miRNA panels yielded an AUC of 0.843, sensitivity of 79% and specificity of 89%. Addition of EV-derived PCA3 levels and clinical characteristics to the biomarker model further improved test accuracy. An AUC of 0.955, sensitivity of 86% and specificity of 93% were obtained. Hence, Vn96-isolated urinary EVs are a clinically applicable and minimally invasive source of mRNA and miRNA biomarkers with potential to improve on the accuracy of prostate cancer screening and diagnosis.
    Print ISSN: 1661-6596
    Electronic ISSN: 1422-0067
    Topics: Chemistry and Pharmacology
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  • 6
    Publication Date: 2021-04-08
    Description: This study evaluated the effects of de-inking paper sludge (DPS) and sewage sludge (SS) application on soil properties, and durum wheat growth and yield. A pot experiment was performed on Calcaric cambisol (clCM) and Cromic Luvisol (coLV) soils. Three DPS rates (0, 30, and 60 Mg ha−1) were studied with and without nitrogen fertilizer (280 kg NH4NO3 ha−1). DPS was also mixed with SS at two rates (5 and 10 Mg ha−1) to highlight the benefits of organic nitrogen compared to mineral nitrogen. DPS improved total organic carbon and nitrogen, mineral nitrogen, and soils cation exchange capacity, the 30% rate provided the greatest improvement in both soils. DPS increased grain and root P, K, Ca, and Mg contents in both soils. It also increased wheat straw N, P, Mg, and Ca for the same soil compared to the control. Mixed DPS treatments with nitrogen fertilizer enhanced grain yield by up to 38% and increased root biomass in the studied soils. Thus, DPS is a potential source of organic matter and a liming agent for acid soils when appropriate supplemental fertilizer is provided.
    Electronic ISSN: 2073-4395
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Economics
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