Development of Analytical Method for the Detection of Nemacur Residues in Cucumber Fruits

Application of Nemacur (Fenamiphos) for pest control may contaminate soil, water and plant with harmful residues and pose threats to human life. This study developed an easy method for the determination of Nemacur residues in cucumber fruits collected from the central markets and from the farm. The method is based on extracting the active ingredients of Nemacur from the commercial formulation and used as a standard material to calibrate the HPLC to determine Nemacur residues in cucumber fruits collected from the central market. Results showed that more than 70% of the active ingredient was extracted from the commercial formulations. Standardization of HPLC with extracted materials showed strong positive association between concentration and peak area relationship. Bioassay investigation showed high mortality of tested organism (fish). Statistical analysis of mortality % between the commercial formulation and those of the extracted ingredient showed no significant differences. These results demonstrated the effectiveness of extracted Nemacur to calibrate HPLC and in bioassay test. Nemacur residues in Cucumber fruits collected from the market were below the detection limit of HPLC, recovery % of Nemacur from control group of cucumber was above 80%. It can be concluded that the method is easily developed and validated by bioassay and chemo-assay

Variation in Early Management Practices in Moderate-to-Severe ARDS in the United States: The Severe ARDS: Generating Evidence Study.

BackgroundAlthough specific interventions previously demonstrated benefit in patients with ARDS, use of these interventions is inconsistent, and patient mortality remains high. The impact of variability in center management practices on ARDS mortality rates remains unknown.Research questionWhat is the impact of treatment variability on mortality in patients with moderate to severe ARDS in the United States?Study design and methodsWe conducted a multicenter, observational cohort study of mechanically ventilated adults with ARDS and Pao2 to Fio2 ratio of ≤ 150 with positive end-expiratory pressure of ≥ 5 cm H2O, who were admitted to 29 US centers between October 1, 2016, and April 30, 2017. The primary outcome was 28-day in-hospital mortality. Center variation in ventilator management, adjunctive therapy use, and mortality also were assessed.ResultsA total of 2,466 patients were enrolled. Median baseline Pao2 to Fio2 ratio was 105 (interquartile range, 78.0-129.0). In-hospital 28-day mortality was 40.7%. Initial adherence to lung protective ventilation (LPV; tidal volume, ≤ 6.5 mL/kg predicted body weight; plateau pressure, or when unavailable, peak inspiratory pressure, ≤ 30 mm H2O) was 31.4% and varied between centers (0%-65%), as did rates of adjunctive therapy use (27.1%-96.4%), methods used (neuromuscular blockade, prone positioning, systemic steroids, pulmonary vasodilators, and extracorporeal support), and mortality (16.7%-73.3%). Center standardized mortality ratios (SMRs), calculated using baseline patient-level characteristics to derive expected mortality rate, ranged from 0.33 to 1.98. Of the treatment-level factors explored, only center adherence to early LPV was correlated with SMR.InterpretationSubstantial center-to-center variability exists in ARDS management, suggesting that further opportunities for improving ARDS outcomes exist. Early adherence to LPV was associated with lower center mortality and may be a surrogate for overall quality of care processes. Future collaboration is needed to identify additional treatment-level factors influencing center-level outcomes.Trial registryClinicalTrials.gov; No.: NCT03021824; URL: www.clinicaltrials.gov

Single-step plasma synthesis of carbon-coated silicon nanoparticles

We have developed a novel single-step technique based on nonthermal, radio frequency (rf) plasmas to synthesize sub-10 nm, core-shell, carbon-coated crystalline Si (c-Si) nanoparticles (NPs) for potential application in Li+ batteries and as fluorescent markers. Hydrogen-terminated c-Si NPs nucleate and grow in a SiH4-containing, low-temperature plasma in the upstream section of a tubular quartz reactor. The c-Si NPs are then transported downstream by gas flow, and are coated with amorphous carbon (a-C) in a second C2H2-containing plasma. X-ray diffraction (XRD), X-ray photoelectron spectroscopy, and in situ attenuated total reflection Fourier transform infrared spectroscopy show that a thin, < 1 nm, 3C-SiC layer forms at the c-Si/a-C interface. By varying the downstream C2H2 plasma rf power, we can alter the nature of the a-C coating as well as the thickness of the interfacial 3C-SiC layer. The transmission electron microscopy (TEM) analysis is in agreement with the Si NP core size determined by Raman spectroscopy, photoluminescence spectroscopy, and XRD analysis. The size of the c-Si NP core, and the corresponding light emission from these NPs, was directly controlled by varying the thickness of the interfacial 3C-SiC layer. This size tunable emission thus also demonstrates the versatility of this technique for synthesizing c-Si NPs for potential applications in light emitting diodes, biological markers, and nanocrystal inks