2,653 research outputs found

    Evaluating the pre-treatment protocol required to produce an effective carbonized waste adsorbent for organic pollution control

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    With the goal of fostering the circular economy, the present work was devised to minimize and manage agricultural waste by transforming it into biochar; a versatile dye removal adsorbent. Waterways across the globe are frequently fouled and contaminated with organic materials, especially via unregulated industrial effluents, producing toxic water supplies. Rhodamine B (RhB) and Methylene blue (MB) dyes were used as model organic pollutants in water. The contaminants were then readily extracted from environmental samples using sustainable wheat straw derived biochars. These materials were utilized in an effort to link the circular economy directly to environmental protection, reducing organic contamination by using a low carbon solution. Herein, two methods were adopted to refine a low temperature carbonized material, dependent on initial pre-treatment; leaching followed by milling (method-I) and milling followed by leaching (method-II). Scanning Electron Microscopy (SEM), nitrogen physisorption, proximate and ultimate analysis and Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) were used to examine the properties of the synthesized materials. It was found that by altering the process of initial waste pre-treatment, an increase in available surface area (6.284 m2g−1–20.754 m2g−1) and pore structure can be found post feedstock pyrolysis. Additionally, FTIR of the biochar post extraction supported the adsorption process of both dyes, demonstrating a change in dye-adsorbent bonding, depending on the initial waste pre-treatment for the biochar. In batch mode, several operating parameters including pH, concentration, duration, and dose were optimized. Kinetics and adsorption isotherm studies for biochar synthesized by method-II pre-treatment (BC-II) revealed that the system follows Pseudo-first-order kinetics and Freundlich adsorption isotherm model with the relative R2 of 0.9989 and 0.9880 for RhB, comparing with 0.9933 and 0.9932 for MB. The optimal produced biochar, BC-II effectively removed 91.06% of RhB from solution at pH 4 and 92.43% for MB at pH 8. This study brings forth a solution to enhance waste management by creating a circular scenario and alleviate environmental contamination by utilizing wheat straw as a biochar adsorbent, produced under controlled and low temperature conditions

    Effect of Cationic Surfactant Head Groups on Synthesis, Growth and Agglomeration Behavior of ZnS Nanoparticles

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    Colloidal nanodispersions of ZnS have been prepared using aqueous micellar solution of two cationic surfactants of trimethylammonium/pyridinium series with different head groups i.e., cetyltrimethylammonium chloride (CTAC) and cetyltrimethylpyridinium chloride (CPyC). The role of these surfactants in controlling size, agglomeration behavior and photophysical properties of ZnS nanoparticles has been discussed. UV–visible spectroscopy has been carried out for determination of optical band gap and size of ZnS nanoparticles. Transmission electron microscopy and dynamic light scattering were used to measure sizes and size distribution of ZnS nanoparticles. Powder X-ray analysis (Powder XRD) reveals the cubic structure of nanocrystallite in powdered sample. The photoluminescence emission band exhibits red shift for ZnS nanoparticles in CTAC compared to those in CPyC. The aggregation behavior in two surfactants has been compared using turbidity measurements after redispersing the nanoparticles in water. In situ evolution and growth of ZnS nanoparticles in two different surfactants have been compared through time-dependent absorption behavior and UV irradiation studies. Electrical conductivity measurements reveal that CPyC micelles better stabilize the nanoparticles than that of CTAC

    Microbiological Lessons Learned from the Space Shuttle

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    After 30 years of being the centerpiece of NASA s human spacecraft, the Space Shuttle will retire. This highly successful program provided many valuable lessons for the International Space Station (ISS) and future spacecraft. Major microbiological risks to crewmembers include food, water, air, surfaces, payloads, animals, other crewmembers, and ground support personnel. Adverse effects of microorganisms are varied and can jeopardize crew health and safety, spacecraft systems, and mission objectives. Engineering practices and operational procedures can minimize the negative effects of microorganisms. To minimize problems associated with microorganisms, appropriate steps must begin in the design phase of new spacecraft or space habitats. Spacecraft design must include requirements to control accumulation of water including humidity, leaks, and condensate on surfaces. Materials used in habitable volumes must not contribute to microbial growth. Use of appropriate materials and the implementation of robust housekeeping that utilizes periodic cleaning and disinfection will prevent high levels of microbial growth on surfaces. Air filtration can ensure low levels of bioaerosols and particulates in the breathing air. The use of physical and chemical steps to disinfect drinking water coupled with filtration can provide safe drinking water. Thorough preflight examination of flight crews, consumables, and the environment can greatly reduce pathogens in spacecraft. The advances in knowledge of living and working onboard the Space Shuttle formed the foundation for environmental microbiology requirements and operations for the International Space Station (ISS) and future spacecraft. Research conducted during the Space Shuttle Program resulted in an improved understanding of the effects of spaceflight on human physiology, microbial properties, and specifically the host-microbe interactions. Host-microbe interactions are substantially affected by spaceflight. Astronaut immune functions were found to be altered. Selected microorganisms were found to become more virulent during spaceflight. The increased knowledge gained on the Space Shuttle resulted in further studies of the host-microbe interactions on the ISS to determine if countermeasures were necessary. Lessons learned from the Space Shuttle Program were integrated into the ISS resulting in the safest space habitat to date

    A Systematic Review of Clinical Practice Guidelines for Identification and Management of Frailty.

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    OBJECTIVE: This study aims to appraise and summarize consistent recommendations from clinical practice guidelines (CPGs) for identification and management of frailty to maintain and improve functional independence of elderly population. METHODS: A systematic search of Ovid MEDLINE, Embase, PubMed, PsycINFO, and CINAHL electronic databases using database-specific search terms in two broad areas "guidelines" and "frailty", and a manual search of websites with the key phrase "frailty guideline" was performed. The inclusion criteria included CPGs focusing on identifying and managing frailty in population >65 years old, published in English since January 2010. Three reviewers independently assessed guideline quality using the AGREE II instrument. Data extraction was performed, followed by compilation and comparison of all recommendations to identify the key consistent recommendations. RESULTS: Six CPGs met the inclusion criteria; however, only three CPGs had high methodological quality in accordance with AGREE II appraisal. The average AGREE II scores of all six CPGs were: 84.5%, 68%, 46.5%, 81.5%, 56.3%, and 60.2% for domains 1-6 (scope and purpose, stakeholder involvement, rigour of development, clarity of presentation, applicability, and editorial independence) respectively. A total of 54 recommendations were identified, with 12 key recommendations suggested frequently by the CPGs. CONCLUSION: The AGREE II instrument identified strengths and weaknesses of the CPGs, but failed to assess clinical implications and feasibility of the guidelines. Further research is needed to improve clinical relevance of CPGs in the identification and management of frailty. The feasibility in implementing these guidelines with regards to cost-effectiveness of frailty screening warrants further investigation

    Imaging in population science: cardiovascular magnetic resonance in 100,000 participants of UK Biobank - rationale, challenges and approaches

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    PMCID: PMC3668194SEP was directly funded by the National Institute for Health Research Cardiovascular Biomedical Research Unit at Barts. SN acknowledges support from the Oxford NIHR Biomedical Research Centre and from the Oxford British Heart Foundation Centre of Research Excellence. SP and PL are funded by a BHF Senior Clinical Research fellowship. RC is supported by a BHF Research Chair and acknowledges the support of the Oxford BHF Centre for Research Excellence and the MRC and Wellcome Trust. PMM gratefully acknowledges training fellowships supporting his laboratory from the Wellcome Trust, GlaxoSmithKline and the Medical Research Council

    Prevalence of Malaria and Anaemia among HIV Infected Pregnant women Receiving Co-trimoxazole Prophylaxis in Tanzania: A Cross Sectional Study in Kinondoni Municipality.

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    HIV-infected pregnant women are particularly more susceptible to the deleterious effects of malaria infection particularly anaemia. In order to prevent opportunistic infections and malaria, a policy of daily co-trimoxazole prophylaxis without the standard Suphadoxine-Pyrimethamine intermittent preventive treatment (SP-IPT) was introduced to all HIV infected pregnant women in the year 2011. However, there is limited information about the effectiveness of this policy. This was a cross sectional study conducted among HIV-infected pregnant women receiving co-trimoxazole prophylaxis in eight public health facilities in Kinondoni Municipality from February to April 2013. Blood was tested for malaria infection and anaemia (haemoglobin <11 g/dl). Data were collected on the adherence to co-trimoxazole prophylaxis and other risk factors for malaria infection and anaemia. Pearson chi-square test, Fischer's exact test and multivariate logistic regression were used in the statistical analysis. This study enrolled 420 HIV infected pregnant women. The prevalence of malaria infection was 4.5%, while that of anaemia was 54%. The proportion of subjects with poor adherence to co-trimoxazole was 50.5%. As compared to HIV infected pregnant women with good adherence to co-trimoxazole prophylaxis, the poor adherents were more likely to have a malaria infection (Adjusted Odds Ratio, AOR = 6.81, 95%CI = 1.35-34.43, P = 0.02) or anaemia (AOR = 1.75, 95%CI = 1.03-2.98, P = 0.039). Other risk factors associated with anaemia were advanced WHO clinical stages, current malaria infection and history of episodes of malaria illness during the index pregnancy. The prevalence of malaria was low; however, a significant proportion of subjects had anaemia. Good adherence to co-trimoxazole prophylaxis was associated with reduction of both malaria infection and anaemia among HIV infected pregnant women
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