3,089 research outputs found

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

    Get PDF
    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

    Get PDF
    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

    Get PDF
    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.

    Full text link
    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

    Ocular injuries in survivors of improvised explosive devices (IED) in commuter trains

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Ocular injuries are common in survivors of terror incidents that involve the use of explosive materials. These explosives are commonly of a High Explosive type (HE) and may be fashioned into improvised explosive devices (IED) that incorporate additional materials to maximise trauma and injuries. Serial IED explosions have occurred in commuter trains in several cities including London and Madrid but data on ocular injuries is limited. We report the ocular injuries of the survivors of a series of IED explosions in crowded commuter trains.</p> <p>Methods</p> <p>28 patients (56 eyes, 28 male, ages ranging from 22 to 52 years (mean 35.27 years) were screened in the triage area or the Intensive Care Unit (ICU). Testing included bedside visual acuity testing, torchlight examination of the anterior segment and dilated (or if necessary, undilated) fundus examination. Selected patients underwent B-scan examination, magnetic resonance imaging of the brain, orbits and the optic nerves or visual evoked potential assessment. The injuries, investigations and procedures were entered into the patient's case sheet as well as into a standardised format suggested by the Indian eye injury registry (IER).</p> <p>Results</p> <p>16 of 28 patients (57.1%) had ocular injuries whereas 12 (42.8%) were found to be normal. Injuries were seen unilaterally in 10 patients and bilaterally in six yielding a total of 22 injured eyes. The common injuries were periorbital haemorrhages (09 eyes, 40%); first or second degree burns to the upper or lower lids (seen in 07 eyes, 31.8 %) and corneal injuries (seen in 08 eyes, 36.3%). Open globe injuries were seen in two eyes of two patients (09%). One patient (4.5%) had a traumatic optic neuropathy.</p> <p>Conclusion</p> <p>Ophthalmologists and traumatologists should be aware of these patterns of ocular injuries. Protocols need to include the screening of large numbers of patients in a short time, diagnostic tests (B scan, visual evoked potential (VEP) etc) and early surgery preferably at the initial triage itself as most of the serious injuries in our studies had been missed or not treated at an initial assessment.</p

    Circulating extracellular vesicles induce monocyte dysfunction and are associated with sepsis and high mortality in cirrhosis

    Get PDF
    BACKGROUND: Sepsis is common in cirrhosis and is often a result of immune dysregulation. Specific stimuli and pathways of inter-cellular communications between immune cells in cirrhosis and sepsis are incompletely understood. Immune cell-derived Extracellular Vesicles (EV) were studied to understand mechanisms of sepsis in cirrhosis. METHODS: Immune-cell derived EV were measured in cirrhosis patients [Child-Turcotte-Pugh (Child) score A, n=15; B n=16; C n=43 and Child-C with sepsis (n=38)], and healthy controls (HC, n=11). In-vitro and in-vivo functional relevance of EV in cirrhosis and associated sepsis was investigated. RESULTS: Monocyte, neutrophil and hematopoietic stem cells associated EV progressively increased with higher Child score (p0.3, p<0.001), which further increased in Child C sepsis than without sepsis(p<0.001); monocyte EV showing the highest association with disease stage [p=0.013; Odds ratio-4.14(1.34-12.42)]. A threshold level of monocyte EV of 53/µl predicted mortality in patients of Child C with sepsis [Odds ratio-6.2 (2.4-15.9), AUROC=0.76, p<0.01]. In vitro EV from cirrhotic with sepsis compared without sepsis, induced mobilization arrest in healthy monocytes within 4 hours (p=0.004), reduced basal oxygen consumption rate (p<0.001) and induced pro-inflammatory genes (p<0.05). The septic-EV on adoptive transfer to C57/BL6J mice, induced sepsis like condition within 24h with leukocytopenia (p=0.005), intrahepatic inflammation with increased CD11b+ cells (p=0.03) and bone marrow hyperplasia (p<0.01). CONCLUSION: Extracellular vesicles induce functional impairment in circulating monocytes and contribute to the development and perpetuation of sepsis. High levels of monocyte EV correlate with mortality and can help early stratification of sicker patients
    • …
    corecore