Direct nitrogen fixation at the edges of graphene nanoplatelets as efficient electrocatalysts for energy conversion

Nitrogen fixation is essential for the synthesis of many important chemicals (e.g., fertilizers, explosives) and basic building blocks for all forms of life (e.g., nucleotides for DNA and RNA, amino acids for proteins). However, direct nitrogen fixation is challenging as nitrogen (N2) does not easily react with other chemicals. By dry ball-milling graphite with N2, we have discovered a simple, but versatile, scalable and eco-friendly, approach to direct fixation of N2 at the edges of graphene nanoplatelets (GnPs). The mechanochemical cracking of graphitic C-C bonds generated active carbon species that react directly with N2 to form five- and six-membered aromatic rings at the broken edges, leading to solution-processable edge-nitrogenated graphene nanoplatelets (NGnPs) with superb catalytic performance in both dye-sensitized solar cells and fuel cells to replace conventional Pt-based catalysts for energy conversion.open302

Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

Biomarkers in Colorectal Cancer

Colorectal cancer remains one of the most frequently diagnosed cancers in the developed world. The advent of new therapeutic agents has further expanded our treatment options. Epidermal growth factor receptor (EGFR) inhibitors have been shown to improve survival in metastatic cancer. However, there remain a substantial proportion of patients who do not benefit from this treatment. KRAS mutation status has been validated to predict the response to EGFR inhibitors with mutant status predicting non-responders. The validation of other predictive and prognostic markers will result in further optimization of the care plan for patient with colorectal cancer; maximising benefits while minimising toxicities. This article aims to provide an update of the various molecular markers for use in detection, prognostication and predicting responses in colon cancer

Cardiologist Evaluation and Approval Was the Primary Predictor of Kidney Transplant Candidacy and Transplantation Among Patients With Reduced Left Ventricular Ejection Fraction

Background. End-stage kidney disease patients with concomitant heart failure (HF) with reduced ejection fraction are often denied kidney transplantation. The aims of this study were to explore factors predictive of suitability for kidney transplant and to assess cardiovascular outcomes in patients with impaired left ventricular ejection fraction (LVEF) after transplant. Methods. We evaluated 109 consecutive adults with LVEF ≤40% at the time of initial kidney transplant evaluation between 2013 and 2018. Posttransplant cardiovascular outcomes were defined as nonfatal myocardial infarction (MI), admission for HF, cardiovascular death, and all-cause mortality. Results. A cardiologist participated in kidney transplant evaluation for 87% of patients and was present at 49% of transplant selection conferences. Twenty-four patients (22%) were denied by a cardiologist for kidney transplant‚ and 59 (54%) were denied by the selection committee, of whom 43 were because of cardiovascular risk. Forty-two (38%) patients were approved for kidney transplant. On univariate analysis, the variables associated with denial for kidney transplant included cardiologist denial, higher cardiac troponin T, prior coronary intervention, cardiovascular event, positive stress study, lower ejection fraction, and lower VO2 max (all P < 0.05). Cardiologist denial was the most significant predictor of denial for kidney transplant in different multivariate models. At a median follow-up of 15 mo, 5 (5%) suffered nonfatal MI, 13 (12%) were hospitalized for HF exacerbation, and 17 (16%) died. Only 22 patients, 52% of those approved, underwent kidney transplant. After kidney transplant, there was 1 death, 1 nonfatal MI, and 3 hospitalizations for HF. Median LVEF improved from 38% before listing to 55% posttransplant. Conclusions. Cardiologist denial was the primary predictor of rejection for kidney transplant. Despite careful selection, prevalence of cardiovascular events and mortality after kidney transplant was 23%. There is need for a structured multidisciplinary approach for patients with impaired LVEF

Singapore SPICE: sedation practices in intensive care evaluation in Singapore - a prospective cohort study of the public healthcare system

INTRODUCTION: A study was conducted to describe the sedation practices of intensive care units (ICUs) in Singapore in terms of drug use, sedation depth and the incidence of delirium in both early ( 48 hours) periods of ICU admission. METHODS: A prospective multicentre cohort study was conducted on patients who were expected to be sedated and ventilated for over 24 hours in seven ICUs (surgical ICU, n = 4; medical ICU, n = 3) of four major public hospitals in Singapore. Patients were followed up to 28 days or until ICU discharge, with four-hourly sedation monitoring and daily delirium assessment by trained nurses. The Richmond Agitation and Sedation Scale (RASS) and Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) were used. RESULTS: We enrolled 198 patients over a five-month period. The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 25.3 ± 9.2, and 90.9% were emergency hospital admissions. Patients were followed up for 1,417 ICU patient days, of which 396 days were in the early period and 1,021 days were in the late period. 7,354 RASS assessments were performed. Propofol and fentanyl were the sedative agents of choice in the early and late periods, respectively. Patients were mostly in the light sedation range, especially in the late period. At least one episode of delirium was seen in 23.7% of patients. CONCLUSION: Sedation practices in Singapore ICUs are characterised by light sedation depth and low incidence of delirium, possibly due to the drugs used

Determining the optimal time to report mortality after lobectomy for lung cancer: An analysis of the time-varying risk of deathCentral MessagePerspective

Objective: Surgical mortality has traditionally been assessed at arbitrary intervals out to 1 year, without an agreed optimum time point. The aim of our study was to investigate the time-varying risk of death after lobectomy to determine the optimum period to evaluate surgical mortality rate after lobectomy for lung cancer. Methods: We performed a retrospective study of patients undergoing lobectomy for lung cancer at our institution from 2015 to 2022. Parametric survival models were assessed and compared with a nonparametric kernel estimate. The hazard function was plotted over time according to the best-fit statistical distribution. The time points at which instantaneous hazard rate peaked and stabilized in the 1-year period after surgery were then determined. Results: During the study period, 2284 patients underwent lobectomy for lung cancer. Cumulative mortality at 30, 90, and 180 days was 1.3%, 2.9%, and 4.9%, respectively. Log-logistic distribution showed the best fit compared with other statistical distribution, indicated by the lowest Akaike information criteria value. The instantaneous hazard rate was greatest during the immediate postoperative period (0.129; 95% confidence interval, 0.087-0.183) and diminishes rapidly within the first 30 days after surgery. Instantaneous hazard rate continued to decrease past 90 days and stabilized only at approximately 180 days. Conclusions: In-hospital mortality is the optimal follow-up period that captures the early-phase hazard during the immediate postoperative period after lobectomy. Thirty-day mortality is not synonymous to “early mortality,” as instantaneous hazard rate remains elevated well past the 90-day time point and only stabilizes at approximately 180 days after lobectomy

Stellated Ag-Pt bimetallic nanoparticles: An effective platform for catalytic activity tuning

10.1038/srep03969Scientific Reports4