Chemical reduction of nitrate by zerovalent iron nanoparticles adsorbed radiation-grafted copolymer matrix

This research specifi cally focused on the development of a novel methodology to reduce excess nitrate in drinking water utilizing zerovalent iron nanoparticles (nZVI)-stabilized radiation-grafted copolymer matrix. nZVI was synthesized by borohydrate reduction of FeCl3 and stabilized on acrylic acid (AAc)-grafted non-woven polyethylene/polypropylene (NWPE/PP-g-AAc) copolymer matrix, which was grafted using gamma radiation. The use of nZVI for environmental applications is challenging because of the formation of an oxide layer rapidly in the presence of oxygen. Therefore, radiation-grafted NWPE/PP synthetic fabric was used as the functional carrier to anchor nZVI and enhance its spreading and stability. The chemical reduction of nitrate by nZVI-adsorbed NWPE/PP-g-AAc (nZVI-Ads-NWP) fabric was examined in batch experiments at different pH values. At low pH values, the protective layers on nZVI particles can be readily dissolved, exposing the pure iron particles for effi cient chemical reduction of nitrate. After about 24 h, at pH 3, almost 96% of nitrate was degraded, suggesting that this reduction process is an acid-driven, surface-mediated process. The nZVI-water interface has been characterized by the 1-pK Basic Stern Model (BSM). An Eley-Rideal like mechanism well described the nitrate reduction kinetics. In accordance with green technology, the newly synthesized nZVI-Ads--NWP has great potential for improving nitrate reduction processes required for the drinking water industry

Risk factors for deliberate self-harm in young people in rural Sri Lanka: a prospective cohort study of 22,000 individuals

Background: Over 90% of youth suicide deaths occur in low- and middle-income countries. Despite this relatively little is known about risk factors in this context. Aims: Investigate risk factors for deliberate self-harm (non-fatal) in young people in rural Sri Lanka. Methods: A prospective cohort study of 22,401 individuals aged 12-18 years with complete data on sex, student status, household asset score, household access to pesticides and household problematic alcohol use. Deliberate self-harm was measured prospectively by reviewing hospital records. Poisson regression estimated incidence rate ratios (IRRs) for the association of risk factors with deliberate self-harm. Results: Females were at higher risk of deliberate self-harm compared to males (IRR 2.05; 95%CI 1.75 – 2.40). Lower asset scores (low compared to high: IRR 1.46, 95%CI 1.12 - 2.00) and having left education (IRR 1.61 95%CI 1.31 – 1.98) were associated with higher risks of deliberate self-harm, with evidence that the effect of not being in school was more pronounced in males (IRR 1.94; 95%CI 1.40 – 2.70) than females. There was no evidence of an association between household pesticide access and deliberate self-harm risk, but problematic household alcohol use was associated with increased risk (IRR 1.23; 95%CI 1.04 – 1.45), with evidence that this was more pronounced in females than males (IRR for females 1.42; 95%CI 1.17 – 1.72). There was no evidence of deliberate self-harm risk being higher at times of school exam stress. Conclusion: Indicators of lower socioeconomic status, not being in school, and problematic alcohol use in households, were associated with increased deliberate self-harm risk in young people

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely