328 research outputs found

    Supported Aqueous-Phase Catalysis for Atom Transfer Radical Polymerization

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    Atom transfer radical polymerization (ATRP) which utilizes transition metal based catalysts is a versatile methodology for the synthesis of a wide spectrum of polymers with controlled architectures. However, high concentrations of soluble catalyst required in an ATRP process makes the final polymer colored and toxic. Thus, the catalyst removal/reduction/recycling remains a challenge in the field of ATRP. Supported catalysts on insoluble solids such as silica gel, polystyrene beads, etc. have been used in ATRP to facilitate the catalyst recovery and recycling. However, the ability of the supported catalysts to mediate a polymerization is substantially reduced due to their reduced mobility and leaching problems. In this thesis, we report a series of novel and recyclable physisorbed CuBr2/N, N, N’, N’’-pentamethyldiethylene-triamine supported catalytic systems operating in conjunction with hydration. Supported aqueous-phase catalysis (SAPC) for ATRP was evaluated for different inorganic (Na-clay, silica and zeolite) and organic (polysaccharides) supports. The hydrated physisorbed supported catalysts were used for the polymerization of benzyl methacrylate and methyl methacrylate using an activator generated electron transfer ATRP process. The catalyst was effectively retained on the surface of supports through hydration as was verified by UV-Vis measurements. The supported catalyst was easily removed from the polymerization by simple filtration process affording a colorless polymer solution. The polymerizations produced high conversion and colorless polymers with moderately narrow polydispersity indices (PDI). The catalyst maintained high activity during the recycling experiments. We also investigated the kinetic and mechanistic behavior of these solid supported polymerization systems. Based on split kinetics experiments and UV-Vis studies it was believed that the activation and deactivation processes took place at the diffused hydrated interface between the solid support and organic phase. The branched (stars and graft) polymers were also synthesized using Na-clay supported catalyst. The produced polymers had narrow PDI and good initiator efficiencies. The functionality of the star polymers was confirmed using 1H NMR and dilute solution properties. The synthesis of graft-copolymer was confirmed by 1H NMR and atomic force microscopy. This thesis demonstrates the successful use of SAPC for ATRP to produce contamination free linear and branched polymers with moderately narrow PDI and high recycling efficiency

    Provisions & Issues Relating to Bail Laws In India

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    The primary object, to hold and arrest a person accused, is to ensure that his / her appearance is at the time of trial and to ensure that in case he/she is convicted guilty he is available to receive the result. The common question is that if the presence of the accused before the court of law could reasonably be ensured without captivating him, it would be unjust and unfair to deprive the accused of his liberty during the pendency of the criminal proceedings against him. The release on the lease is very important to an accused because the result of pre-trial detention is itself very critical as the accused will be subjected to the psychological and physical deprivation of jail life, the accused will lose his / her job, and prevents him from contributing effectively to the preparation of his defense and most importantly the burden of detention often falls on the innocent members of his family. The article briefly tries to discuss the impact of the law in India on its poor subjects, by briefly emphasizing the history of the lease system to the current prevailing practice in India

    Research Infrastructure Challenges for Graduate Programs in STEM Disciplines at Minority Institutions

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    It is much more challenging to perform experimental research functions at many minority institutions, because of lack of adequate research infrastructure. This is especially true if one wishes to initiate and implement masters and doctoral degree program in physics. In the present paper, an attempt is made to discuss the various hurdles encountered by the authors in the establishment of Master's and Doctoral degree programs in physics at one of the HBCUs (Historically Black Colleges and Universities). The department got no special or necessary treatment and faculty members are asked to teach as much course work as any other undergraduate department on the campus. It was very hard to convince university administration that giving less teaching load to research producing department faculty, shall culminate in abundant funding for the future years. This scenario created an extra heavy pressure on the faculty to continue the program. Some of the challenges included the resistance of some faculty and administrators to change, lack of sufficient release time for research producing faculty, and potential variation in funding or support with changes in the state education budget proration or members of the administration. In spite of the indirect cost recovery, very little infrastructure facilities was provided and the federal funding agencies did not want to interfere in the administration of the university. Various issues of recruiting and mentoring minority students, retention in the STEM disciplines as well as research infrastructure challenges at an HBCU university are presented

    Scimitar syndrome - A rare cause of recurrent pneumonia

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    Scimitar syndrome is a congenital anomaly characterized by anomalous drainage of the right lung into inferior vena cava. This may be associated with other anomalies in the form of pulmonary hypoplasia, systemic arterial supply of right lung, and congenital heart diseases. We report an infant with recurrent pneumonia who turned out to be a case of scimitar syndrome on further workup. The patient was managed surgically by selective embolization of the artery from celiac trunk to sequestered lung. This case report highlights the fact that scimitar syndrome should be suspected in a patient with recurrent pneumonia with typical chest X-ray findings

    A Deep Learning Approach to Helmet Detection for Road Safety

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    509-512The rapid growth in the commute and vehicles has made exponential growth in the progress of mankind. This growth besides its positive aspects comes with a concern of saving life on road due to accidents. And, hence the technological advancements in the field of machine learning are required to cope up with the challenges such as road safety and traffic rule violations. According to the survey the majority of the life lost in road accidents is due to the negligence of wearing a helmet on a two wheeler vehicle. The enforcement of the traffic rules regarding this violation proves to be a challenge due to dense population and low rate of detection which is primarily caused by the lack of an automated system to detect the violation and take the necessary action. The growing population and the growing number of vehicles cause the manual systems in place to fail in curbing the issue. The recent advancements in Deep Learning and Image Processing provide an opportunity to solve this problem. This manuscript presents the implementation of a system which detects three objects namely the vehicle, non-usage of a helmet and the number plate of the vehicle under consideration using Tensorflow. Deep learning using the SSD MobileNet V2 is the primary technique used to implement the system. The system has been tested under different use cases with successful results

    Delirium Associated with Olanzapine Therapy in an Elderly Male with Bipolar Affective Disorder

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    Atypical antipsychotic medications are commonly used to treat symptoms of delirium. Olanzapine has been successfully used in the treatment of delirium. However, there have been few case reports of delirium associated with olanzapine. We hereby report a case of delirium associated with olanzapine therapy. Possible risk factors and underlying pathogenesis is discussed

    Pulsed Laser Deposition of Nanoporous Cobalt Thin Films

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    Nanoporous cobalt thin films were deposited on anodized aluminum oxide (AAO) membranes at room temperature using pulsed laser deposition. Scanning electron microscopy demonstrated that the nanoporous cobalt thin films retained the monodisperse pore size and high porosity of the anodized aluminum oxide substrates. Temperature- and field-dependent magnetic data obtained between 10 K and 350 K showed large hysteresis behavior in these materials. The increase of coercivity values was larger for nanoporous cobalt thin films than for multilayered cobalt/alumina thin films. The average diameter of the cobalt nanograins in the nanoporous cobalt thin films was estimated to be ~5 nm for blocking temperatures near room temperature. These results suggest that pulsed laser deposition may be used to fabricate nanoporous magnetic materials with unusual properties for biosensing, drug delivery, data storage, and other technological applications

    Defining the Enablers and Barriers to the Implementation of Large-scale, Health Care-Related Mobile Technology: Qualitative Case Study in a Tertiary Hospital Setting

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    BACKGROUND: The successful implementation of clinical smartphone apps in hospital settings requires close collaboration with industry partners. A large-scale, hospital-wide implementation of a clinical mobile app for health care professionals developed in partnership with Google Health and academic partners was deployed on a bring-your-own-device basis using mobile device management at our UK academic hospital. As this was the first large-scale implementation of this type of innovation in the UK health system, important insights and lessons learned from the deployment may be useful to other organizations considering implementing similar technology in partnership with commercial companies. OBJECTIVE: The aims of this study are to define the key enablers and barriers and to propose a road map for the implementation of a hospital-wide clinical mobile app developed in collaboration with an industry partner as a data processor and an academic partner for independent evaluation. METHODS: Semistructured interviews were conducted with high-level stakeholders from industry, academia, and health care providers who had instrumental roles in the implementation of the app at our hospital. The interviews explored the participants' views on the enablers and barriers to the implementation process. The interviews were analyzed using a broadly deductive approach to thematic analysis. RESULTS: In total, 14 participants were interviewed. Key enablers identified were the establishment of a steering committee with high-level clinical involvement, well-defined roles and responsibilities between partners, effective communication strategies with end users, safe information governance precautions, and increased patient engagement and transparency. Barriers identified were the lack of dedicated resources for mobile change at our hospital, risk aversion, unclear strategy and regulation, and the implications of bring-your-own-device and mobile device management policies. The key lessons learned from the deployment process were highlighted, and a road map for the implementation of large-scale clinical mobile apps in hospital settings was proposed. CONCLUSIONS: Despite partnering with one of the world's biggest technology companies, the cultural and technological change required for mobile working and implementation in health care was found to be a significant challenge. With an increasing requirement for health care organizations to partner with industry for advanced mobile technologies, the lessons learned from our implementation can influence how other health care organizations undertake a similar mobile change and improve the chances of successful widespread mobile transformation

    Association of common genetic variants with lipid traits in the Indian population.

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    Genome-wide association studies (GWAS) have been instrumental in identifying novel genetic variants associated with altered plasma lipid levels. However, these quantitative trait loci have not been tested in the Indian population, where there is a poorly understood and growing burden of cardiometabolic disorders. We present the association of six single nucleotide polymorphisms in 1671 sib pairs (3342 subjects) with four lipid traits: total cholesterol, triglycerides, high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C). We also investigated the interaction effects of gender, location, fat intake and physical activity. Each copy of the risk allele of rs964184 at APOA1 was associated with 1.06 mmol/l increase in triglycerides (SE = 0.049; p = 0.006), rs3764261 at CETP with 1.02 mmol/l increase in both total cholesterol (SE = 0.042; p = 0.017) and HDL-C (SE = 0.041; p = 0.008), rs646776 at CELSR2-PSRC1-SORT1 with 0.96 mmol/l decrease in cholesterol (SE = 0.043; p = 0.0003) and 0.15 mmol/l decrease in LDL-C levels (SE = 0.043; p = 0.0003) and rs2954029 at TRIB1 with 1.02 mmol/l increase in HDL-C (SE = 0.039; p = 0.047). A combined risk score of APOA1 and CETP loci predicted an increase of 1.25 mmol/l in HDL-C level (SE = 0.312; p = 0.0007). Urban location and sex had strong interaction effects on the genetic association of most of the studied loci with lipid traits. To conclude, we validated four genetic variants (identified by GWAS in western populations) associated with lipid traits in the Indian population. The interaction effects found here may explain the sex-specific differences in lipid levels and their heritability. Urbanization appears to influence the nature of the association with GWAS lipid loci in this population. However, these findings will require replication in other Indian populations
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