Phytochemical studies, antioxidant activities and identification of active compounds using GC–MS of Dryopteris cochleata leaves

The increasing interest in powerful biological activity of plant phenolics and flavonoids outlined the necessity of determining their contents in Dryopteris cochleata leaves. The present investigation comprises, estimation of total phenolics, flavonoids, flavonols, tannins, carbohydrates, vitamin-C and protein content accompanied by an important in vitro antioxidant assays like DPPH-radical scavenging activity and reducing power for various leaf extracts. Quantitative screening provided a gateway to assess all the estimations, among which the significant role was played by the acetone extract. IC50 and EC50 of the in vitro assays of acetone depicted striking evidence in contrast to the other extracts. Supportively, GC–MS analysis revealed that many useful constituents indicating D. cochleata leaves could be useful for preparation of neutraceuticals as potent antioxidant to treat various human diseases and its complications

Sulfur Vacancy-Driven Band Splitting and Phonon Anharmonicity Enhance the Thermoelectric Performance in <i>n</i>‑Type CuFeS₂

Ternary chalcogenides of CuFeS2–x (x = 0.00–0.20) chalcopyrites were synthesized via vacuum melting reaction/uniaxial hot pressing, and their thermoelectrical properties were investigated at temperatures ranging from 315 to 605 K. The crystal structures and microstructures of all samples were examined using powder X-ray diffraction and scanning electron microscopy, respectively. X-ray photoelectron spectroscopy (XPS) was utilized to validate the oxidation states of Cu1+, Fe3+, and S2– in CuFeS2–x. As sulfur vacancy increased, the power factor, S2σ, increased from ∼0.18 mW/mK2 for CuFeS2 to ∼0.20 mW/mK2 for CuFeS1.8 at 605 K due to an increase in the carrier concentration, as evidenced by theoretical calculations using density functional theory (DFT). Additionally, the total thermal conductivity, κtotal, was significantly reduced from ∼2.26 to ∼0.83 W/mK at 605 K for the compositions of CuFeS2 and CuFeS1.8, respectively, owing to the enhanced phonon scattering from the strong acoustic phonon coupling, Umklapp process, and sulfur vacancy-driven low group velocity. Consequently, the sulfur-deficient CuFeS1.8 sample exhibited the highest thermoelectric figure of merit, zT, of 0.14 at 605 K with a notably high hardness of 158 Hv, proving that it is an efficient thermoelectric material for intermediate temperatures

Prospective observational cohort study on grading the severity of postoperative complications in global surgery research

Background The Clavien–Dindo classification is perhaps the most widely used approach for reporting postoperative complications in clinical trials. This system classifies complication severity by the treatment provided. However, it is unclear whether the Clavien–Dindo system can be used internationally in studies across differing healthcare systems in high- (HICs) and low- and middle-income countries (LMICs). Methods This was a secondary analysis of the International Surgical Outcomes Study (ISOS), a prospective observational cohort study of elective surgery in adults. Data collection occurred over a 7-day period. Severity of complications was graded using Clavien–Dindo and the simpler ISOS grading (mild, moderate or severe, based on guided investigator judgement). Severity grading was compared using the intraclass correlation coefficient (ICC). Data are presented as frequencies and ICC values (with 95 per cent c.i.). The analysis was stratified by income status of the country, comparing HICs with LMICs. Results A total of 44 814 patients were recruited from 474 hospitals in 27 countries (19 HICs and 8 LMICs). Some 7508 patients (16·8 per cent) experienced at least one postoperative complication, equivalent to 11 664 complications in total. Using the ISOS classification, 5504 of 11 664 complications (47·2 per cent) were graded as mild, 4244 (36·4 per cent) as moderate and 1916 (16·4 per cent) as severe. Using Clavien–Dindo, 6781 of 11 664 complications (58·1 per cent) were graded as I or II, 1740 (14·9 per cent) as III, 2408 (20·6 per cent) as IV and 735 (6·3 per cent) as V. Agreement between classification systems was poor overall (ICC 0·41, 95 per cent c.i. 0·20 to 0·55), and in LMICs (ICC 0·23, 0·05 to 0·38) and HICs (ICC 0·46, 0·25 to 0·59). Conclusion Caution is recommended when using a treatment approach to grade complications in global surgery studies, as this may introduce bias unintentionally

The surgical safety checklist and patient outcomes after surgery: a prospective observational cohort study, systematic review and meta-analysis

© 2017 British Journal of Anaesthesia Background: The surgical safety checklist is widely used to improve the quality of perioperative care. However, clinicians continue to debate the clinical effectiveness of this tool. Methods: Prospective analysis of data from the International Surgical Outcomes Study (ISOS), an international observational study of elective in-patient surgery, accompanied by a systematic review and meta-analysis of published literature. The exposure was surgical safety checklist use. The primary outcome was in-hospital mortality and the secondary outcome was postoperative complications. In the ISOS cohort, a multivariable multi-level generalized linear model was used to test associations. To further contextualise these findings, we included the results from the ISOS cohort in a meta-analysis. Results are reported as odds ratios (OR) with 95% confidence intervals. Results: We included 44 814 patients from 497 hospitals in 27 countries in the ISOS analysis. There were 40 245 (89.8%) patients exposed to the checklist, whilst 7508 (16.8%) sustained ≥1 postoperative complications and 207 (0.5%) died before hospital discharge. Checklist exposure was associated with reduced mortality [odds ratio (OR) 0.49 (0.32–0.77); P\u3c0.01], but no difference in complication rates [OR 1.02 (0.88–1.19); P=0.75]. In a systematic review, we screened 3732 records and identified 11 eligible studies of 453 292 patients including the ISOS cohort. Checklist exposure was associated with both reduced postoperative mortality [OR 0.75 (0.62–0.92); P\u3c0.01; I2=87%] and reduced complication rates [OR 0.73 (0.61–0.88); P\u3c0.01; I2=89%). Conclusions: Patients exposed to a surgical safety checklist experience better postoperative outcomes, but this could simply reflect wider quality of care in hospitals where checklist use is routine

Critical care admission following elective surgery was not associated with survival benefit: prospective analysis of data from 27 countries

This was an investigator initiated study funded by Nestle Health Sciences through an unrestricted research grant, and by a National Institute for Health Research (UK) Professorship held by RP. The study was sponsored by Queen Mary University of London