343 research outputs found

    Photochemical Thiolation of Carbon Particles with Mercaptoproyltrimethoxysilane

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    Surface modification of carbon black (CB) is an important tool to refashion properties of its composites. CB surface modification is usually practiced through thermal procedures. However, environmental concerns have provided the base to rethink for alternate methods, particularly photochemical methods that are considered comparatively eco-friendly due to reduced chemical and thermal waste. Present investigation is based on a photochemical method for CB surface modification that has effectively modified particle surface with alkoxysilane. This method carries the active centers, generated by photoinitiator, to the shaded areas which otherwise are not possible to reach. Hence, this reaction scheme has prevailed over huge activation barrier without thermal support. A photo-thermal modification method has also been utilized for comparative analysis. Effectiveness of photochemical modification method to alter the surface of CB has been confirmed through different instrumental techniques, including XPS, TGA, FTIR, Raman and SEM

    Evaluation of Novel Bio-friendly Two-step Process in the Removal of Heavy Metals from the Wastewater

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    Two-step treatment technique was developed for the treatment of water by Pseudomonas aeroginosa in a bioreactor in a first phase and then the bacterial treated water was treated with the vetiver grass, cattails and water hyacinth in second phase. Two-step process of bioremediation of 13 days was found to be satisfactory for As, Ba, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn in compared to the direct treatments with vetiver grass, cattails and water hyacinth in 20 days. As the plants cannot work or tolerate the higher concentrations of heavy metals, so with the first step on an average 52.48% reduction of heavy metals were done within 5 days. It was observed that 100% removal of Pb was found by two-step process of Pseudomas aeroginosa with cattails and water hyacinth, respectively in 13 days, while 98.16% removal of Pb was found by direct plant treatment of water hyacinth in 20 days. It was clear that the two-step treatment for vetiver grass, cattails and water hyacinth were found as the most effective treatments

    Allelopathic Potential of Rice Varieties against Spinach (Spinacia oleracea)

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    Two laboratory experiments were conducted to investigate the allelopathic effects of rice varieties on spinach (Spinacia aleracea L.). Fifteen rice varieties were included for evaluation. Two methods viz. Sandwich method and Relay seeding method were used to observe the allelopathic effects of rice varieties on seed germination, mean germination time, shoot and root length and dry matter production of spinach as a test crop. Average inhibition in spinach growth was calculated to evaluate the allelopathic potential of the rice varieties. All the selected varieties of rice were more or less detrimental to studied characters of spinach. WITA12 resulted in about 48% average percent inhibition of spinach growth. On the basis of average percent inhibition rice varieties ranked in order of WITA12>Dular>WITA3>BR26>BRRI dhan42>BRRI dhan39>BRRI dhan31>BRRI dhan44>BRRI dhan40>BR19>BRRI dhan43>BRRI dhan46>BRRI dhan47>BRRI dhan45>BRRI dhan28. Both the evaluation methods were positively correlated in determining percent reduction in most of the parameters of spinach due to allelopathic effects of rice

    Structural dynamic response of an unreinforced masonry house using non-destructive forced vibration

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    The results of non-destructive forced vibration tests on a small-scale unreinforced masonry house with a flexible timber diaphragm are presented. The primary purpose of this study was to investigate the dynamic responses between the as-built and retrofitted structures. This includes assessment of diaphragm response, wall-diaphragm connection details, in-plane wall response, out-of-plane wall response, and the response of wall corners. The test protocols were designed to investigate two types of retrofit techniques consisting of a plywood-retrofit on the diaphragm, and a connection-retrofit between the wall and diaphragm. From the results, one can see that the natural frequency and mode shapes of the first translational mode were affected. The force transfer mechanism of the as-built structure was significantly improved after applying both retrofits whereas each technique shows distinctive enhancements on the structure overall response

    Morphological variations of explosive residue particles and implications for understanding detonation mechanisms

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    The possibility of recovering undetonated explosive residues following detonation events is well-known; however, the morphology and chemical identity of these condensed phase postblast particles remains undetermined. An understanding of the postblast explosive particle morphology would provide vital information during forensic examinations, allowing rapid initial indication of the explosive material to be microscopically determined prior to any chemical analyses and thereby saving time and resources at the crucial stage of an investigation. In this study, condensed phase particles collected from around the detonations of aluminized ammonium nitrate and RDX-based explosive charges were collected in a novel manner utilizing SEM stubs. By incorporating the use of a focused ion beam during analysis, for the first time it is possible to determine that such particles have characteristic shapes, sizes, and internal structures depending on the explosive and the distance from the detonation at which the particles are recovered. Spheroidal particles (10–210 μm) with microsurface features recovered following inorganic charge detonations were dissimilar to the irregularly shaped particles (5–100 μm) recovered following organic charge firings. Confirmatory analysis to conclude that the particles were indeed explosive included HPLC-MS, Raman spectroscopy, and mega-electron volt–secondary ionization mass spectrometry. These results may impact not only forensic investigations but also the theoretical constructs that govern detonation theory by indicating the potential mechanisms by which these particles survive and how they vary between the different explosive types.EPSRC Grant EP/G037264/

    The effect of completeness of revascularization during CABG with single versus multiple arterial grafts

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    IntroductionIncomplete coronary revascularization is associated with suboptimal outcomes. We investigated the longâ term effects of Incomplete, Complete, and Supraâ complete revascularization and whether these effects differed in the setting of singleâ arterial and multiâ arterial coronary artery bypass graft (CABG).MethodsWe analyzed 15â year mortality in 7157 CABG patients (64.1â ±â 10.5 years; 30% women). All patients received a left internal thoracic artery to left anterior descending coronary artery graft with additional venous grafts only (singleâ arterial) or with at least one additional arterial graft (multiâ arterial) and were grouped based on a completeness of revascularization index (CRIâ =â number of grafts minus the number of diseased principal coronary arteries): Incomplete (CRIâ â ¤â â 1 [Nâ =â 320;4.5%]); Complete (CRIâ =â 0 [Nâ =â 2882;40.3%]; reference group); and two Supraâ complete categories (CRIâ =â +1[Nâ =â 3050; 42.6%]; CRIâ â ¥â +â 2 [Nâ =â 905; 12.6%]). Riskâ adjusted mortality hazard ratios (AHR) were calculated using comprehensive propensity score adjustment by Cox regression.ResultsIncomplete revascularization was rare (4.5%) but associated with increased mortality in all patients (AHR [95% confidence interval]â =â 1.53 [1.29â 1.80]), those undergoing singleâ arterial CABG (AHRâ =â 1.27 [1.04â 1.54]) and multiâ arterial CABG (AHRâ =â 2.18 [1.60â 2.99]), as well as in patients with 3â Vessel (AHRâ =â 1.37 [1.16â 1.62]) and, to a lesser degree, with 2â Vessel (AHRâ =â 1.67 [0.53â 5.23]) coronary disease. Supraâ complete revascularization was generally associated with incrementally decreased mortality in all patients (AHR [CRIâ =â +1]â =â 0.94 [0.87â 1.03]); AHR [CRIâ â ¥â +2]â =â 0.74 [0.64â 0.85]), and was driven by a significantly decreased mortality risk in singleâ arterial CABG (AHR [CRIâ =â +1]â =â 0.90 [0.81â 0.99]; AHR [CRIâ â ¥â +2]â =â 0.64 [0.53â 0.78]); and 3â Vessel disease patients (AHR [CRIâ =â +1]â =â 0.94 [0.86â 1.04]; and AHR [CRIâ â ¥â +2]â =â 0.75 [0.63â 0.88]) with no impact in multiâ arterial CABG (AHR [CRIâ =â +1]â =â 1.07 [0.91â 1.26]; AHR [CRIâ â ¥â +2]â =â 0.93 [0.73â 1.17]).ConclusionsIncomplete revascularization is associated with decreased late survival, irrespective of grafting strategy. Alternatively, supraâ complete revascularization is associated with improved survival in patients with 3â Vessel CAD, and in singleâ arterial but not multiâ arterial CABG.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146364/1/jocs13810.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146364/2/jocs13810_am.pd

    Radiation Therapy in Addition to Gross Total Resection of Retroperitoneal Sarcoma Results in Prolonged Survival: Results from a Single Institutional Study

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    Purpose. Typical treatment of retroperitoneal sarcomas (RPSs) is surgery with or without radiation therapy for localized disease. With surgery alone, local failure rates are as high as 90%; this led to radiation therapy playing an important role in the treatment of RPSs. Methods. Thirty-one patients with retroperitoneal sarcoma treated with gross total resection and radiation therapy make up this retrospective analysis. Nineteen were treated preoperatively and 12 postoperatively (median dose, 59.4 Gy)—sixteen also received intraoperative radiation therapy (IORT) (median dose, 11 Gy). Patients were followed with stringent regimens, including frequent CT scans of the chest, abdomen, and pelvis. Results. With a median follow-up of 19 months (range 1–66 months), the 2-year overall survival (OS) rate is 70% (median, 52 months). The 2-year locoregional control (LRC) rate is 77% (median, 61.6 months). The 2-year distant disease free survival (DDFS) rate is 70% (median not reached). There were no differences in radiation-related acute and late toxicities among patients treated pre- versus postoperatively, whether with or without IORT. Conclusions. Compared to surgery alone, neoadjuvant or adjuvant radiation therapy offers patients with RPS an excellent chance for long-term LRC, DDS, and OS. The integration of modern treatment planning for external beam radiation therapy and IORT allows for higher doses to be delivered with acceptable toxicities

    production and characterization of ni and cu composite coatings by electrodeposition reinforced with carbon nanotubes or graphite nanoplatelets

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    Electrodeposition is well-known as a versatile and economical processing technique to produce metal coatings on conductive substrates. Recently, it has been gaining increasing interest also for the production of tailored composite coatings, containing for instance floropolymers or silicon carbide. A more novel approach concerns the use of carbon nanotubes or even graphene, in the form of graphite nano-platelets. The production of Ni- and Cu-based nanocomposites containing carbon nanoreinforcements was carried out by using standard electrodeposition conditions, but with a particular attention to the dispersion of the nanotubes. The obtained coatings were strong and well adherent to the steel substrate, and presented rather well dispersed carbon nanotubes or graphite nanoplatelets, even if some agglomerates could be present in samples obtained from highly concentrated suspensions. In the case of nickel-based composite coatings, the size of nickel grains was reduced, and pin-on-disc tests demonstrated a significant increase in the life of the coating. In the case of copper-based composite coatings, thermal diffusivity measurements demonstrated that the carbon nanomaterial does not reduce the conductivity of the pure copper coating

    A study of employee affective organisational commitment and retention in Pakistan:the roles of psychological contract breach and norms of reciprocity

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    Social exchange theory and notions of reciprocity have long been assumed to explain the relationship between psychological contract breach and important employee outcomes. To date, however, there has been no explicit testing of these assumptions. This research, therefore, explores the mediating role of negative, generalized, and balanced reciprocity, in the relationships between psychological contract breach and employees’ affective organizational commitment and turnover intentions. A survey of 247 Pakistani employees of a large public university was analyzed using structural equation modeling and bootstrapping techniques, and provided excellent support for our model. As predicted, psychological contract breach was positively related to negative reciprocity norms and negatively related to generalized and balanced reciprocity norms. Negative and generalized (but not balanced) reciprocity were negatively and positively (respectively) related to employees’ affective organizational commitment and fully mediated the relationship between psychological contract breach and affective organizational commitment. Moreover, affective organizational commitment fully mediated the relationship between generalized and negative reciprocity and employees’ turnover intentions. Implications for theory and practice are discussed

    Safety and pharmacokinetics of anti-TFPI antibody (concizumab) in healthy volunteers and patients with hemophilia: a randomized first human dose trial

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    BACKGROUND: Prophylaxis with either intravenous (i.v.) factor VIII (FVIII) or FIX is the gold standard of care for patients with severe hemophilia. A monoclonal antibody (concizumab) targeting tissue factor pathway inhibitor (TFPI) that can be administered subcutaneously (s.c.) has the potential to alter current concepts of prophylaxis in hemophilia. OBJECTIVES: To evaluate the safety and describe the pharmacokinetics and pharmacodynamics of single-dose concizumab in healthy volunteers and patients with hemophilia A or B. METHODS: In this first human dose, phase 1, multicenter, randomized, double-blind, placebo-controlled trial escalating single i.v. (0.5-9000 μg kg(-1) ) or s.c. (50-3000 μg kg(-1) ) doses of concizumab were administered to healthy volunteers (n = 28) and hemophilia patients (n = 24). RESULTS: Concizumab had a favorable safety profile after single i.v. or s.c. administration. There were no serious adverse events and no anti-concizumab antibodies. No clinically relevant changes in platelets, prothrombin time, activated partial thromboplastin time, fibrinogen, or antithrombin were found. A dose-dependent procoagulant effect of concizumab was seen as increased levels of D-dimers and prothrombin fragment 1 + 2. Nonlinear pharmacokinetics of concizumab was observed due to target-mediated clearance. A maximum mean AUC0-∞ of 33 960 h μg mL(-1) and a maximum mean concentration of 247 μg mL(-1) was measured at the highest dose. CONCLUSIONS: Concizumab showed a favorable safety profile after i.v. or s.c. administration and nonlinear pharmacokinetics was observed due to target-mediated clearance. A concentration-dependent procoagulant effect of concizumab was observed, supporting further study into the potential use of s.c. concizumab for hemophilia treatment
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