Microwave-assisted depolymerization of various types of waste lignins over two-dimensional CuO/BCN catalysts

© 2020 The Royal Society of Chemistry. Valorization of lignin to valuable chemicals and biofuels increases the economic viability of sustainable biorefineries. This work aimed at elucidating how the lignin structures recovered from various agricultural and industrial residues governed the downstream catalytic conversion. Three types of lignins, namely bio-enzymatic lignin (BL), organosolv lignin (OL), and Kraft lignin (KL), were fully characterized by HSQC-NMR, TGA, FTIR, and SEM to obtain a detailed description of their structures. In consideration of redox-active CuO and highly active carbon-modified boron nitride (BCN) in oxidative dehydrogenation, a two-dimensional CuO/BCN catalyst was prepared and explored in microwave-assisted lignin conversion to improve the yields of aromatic monomers. BL achieved the highest yield of monomers (10 wt%) over the CuO/BCN catalyst after the 3rd cycle in 30 min under mild conditions (200 °C). The yields of bio-oils reached 70 wt% in 10 min when BL and OL were used as the substrate. High efficiency of the microwave-assisted reaction was illustrated by comparing with that of the hydrothermal reaction. This work demonstrated strong dependence of the conversion efficiency on the interunit linkages and functional groups of lignin structures. The strong metal-support interaction between CuO and BCN not only facilitated lignin depolymerization via the promoted electron transfer, but also enhanced the stability of Cu catalysts under hydrothermal conditions. In addition, elucidation of the catalyst redox evolution shed light on the role of the CuO/BCN catalyst in lignin depolymerization in recycle runs

In Search of Excellence: Convex versus Concave Noble Metal Nanostructures for Electrocatalytic Applications

Controlling the shape of noble metal nanoparticles is a challenging but important task in electrocatalysis. Apart from hollow and nanocage structures, concave noble metal nanoparticles are considered a new class of unconventional electrocatalysts that exhibit superior electrocatalytic properties as compared with those of conventional nanoparticles (including convex and flat ones). Herein, several facile and highly reproducible routes for synthesizing nanostructured concave noble metal materials reported in the literature are discussed, together with their advantages over noble metal nanoparticles with convex shapes. In addition, possible ways of optimizing the synthesis procedure and enhancing the electrocatalytic characteristics of concave metal nanoparticles are suggested. Nanostructured noble metals with concave features are found to show better catalytic activity and stability hence improve their practical applicability in electrocatalysis

Effect of N2 flow rate on kinetic investigation of lignin pyrolysis

Fast pyrolysis of lignin can obtain valuable products such as bio-oil, bio-chemical, syngas, and biochar. In this study, two types of lignin known as brown solid from the byproduct of cellulosic ethanol fermentation and commercial dealkaline lignin from the papermaking process were used for pyrolysis in a 3-L batch reactor at 300–450 °C. The product composition in the liquid and gas phases were analyzed by using gas chromatography-mass spectrometry/Flame-ionization detector/thermal conductivity detector (GC-MS/FID/TCD). Increasing the N flow rate to 150 mL/min was sufficient to increase the production of bio-oil/bio-organics up to 15% for brown solid pyrolysis. In contrast, the biochemical production during dealkaline lignin pyrolysis was not sensitive to the change of the N flow rate. The amount of biochar produced in the pyrolysis (~60%) slightly changed at various pyrolysis temperature and gas flow rate, which could be due to the relatively low pyrolysis temperature that was insufficient to decompose the lignin. The GC-MS analysis also revealed that C7–C8 compounds, which represented the phenolic compounds, were the most abundant in the liquid products. Kinetic models of the pyrolysis were established based on the thermogravimetric analysis

High surface area nanoporous carbon derived from high quality jute from Bangladesh

We report an economically viable and environment-friendly strategy for the preparation of nanoporous carbon (NC) from jute which is one of the most abundant natural fibers produced in Bangladesh and some South Asian countries. Nitrogen adsorption-desorption isotherms, X-ray diffraction, Raman spectroscopy, UV spectroscopy, and scanning/transmission electron microscopy were performed to characterize the obtained NC. Three different types of jute-derived NCs have been synthesized at three different temperatures, 700 °C, 800 °C and 900 °C. The NC prepared at 800 °C resulted in a high surface area (981 m g) and was associated with the retention of the original fibrous shapes. This study shows a promising future for jute as a natural precursor for NCs for a myriad of applications ranging from water purification to gas separation to energy conversion and storage

Androgens in men study (AIMS) : Protocol for meta-analyses of individual participant data investigating associations of androgens with health outcomes in men

Introduction This study aims to clarify the role(s) of endogenous sex hormones to influence health outcomes in men, specifically to define the associations of plasma testosterone with incidence of cardiovascular events, cancer, dementia and mortality risk, and to identify factors predicting testosterone concentrations. Data will be accrued from at least three Australian, two European and four North American population-based cohorts involving approximately 20 000 men. Methods and analysis Eligible studies include prospective cohort studies with baseline testosterone concentrations measured using mass spectrometry and 5 years of follow-up data on incident cardiovascular events, mortality, cancer diagnoses or deaths, new-onset dementia or decline in cognitive function recorded. Data for men, who were not taking androgens or drugs suppressing testosterone production, metabolism or action; and had no prior orchidectomy, are eligible. Systematic literature searches were conducted from 14 June 2019 to 31 December 2019, with no date range set for searches. Aggregate level data will be sought where individual participant data (IPD) are not available. One-stage IPD random-effects meta-analyses will be performed, using linear mixed models, generalised linear mixed models and either stratified or frailty-augmented Cox regression models. Heterogeneity in estimates from different studies will be quantified and bias investigated using funnel plots. Effect size estimates will be presented in forest plots and non-negligible heterogeneity and bias investigated using subgroup or meta-regression analyses. Ethics and dissemination Ethics approvals obtained for each of the participating cohorts state that participants have consented to have their data collected and used for research purposes. The Androgens In Men Study has been assessed as exempt from ethics review by the Human Ethics office at the University of Western Australia (file reference number RA/4/20/5014). Each of the component studies had obtained ethics approvals; please refer to respective component studies for details. Research findings will be disseminated to the scientific and broader community via the publication of four research articles, with each involving a separate set of IPD meta-analyses (articles will investigate different, distinct outcomes), at scientific conferences and meetings of relevant professional societies. Collaborating cohort studies will disseminate findings to study participants and local communities. PROSPERO registration number CRD42019139668

Whole-genome sequencing reveals host factors underlying critical COVID-19

Altres ajuts: Department of Health and Social Care (DHSC); Illumina; LifeArc; Medical Research Council (MRC); UKRI; Sepsis Research (the Fiona Elizabeth Agnew Trust); the Intensive Care Society, Wellcome Trust Senior Research Fellowship (223164/Z/21/Z); BBSRC Institute Program Support Grant to the Roslin Institute (BBS/E/D/20002172, BBS/E/D/10002070, BBS/E/D/30002275); UKRI grants (MC_PC_20004, MC_PC_19025, MC_PC_1905, MRNO2995X/1); UK Research and Innovation (MC_PC_20029); the Wellcome PhD training fellowship for clinicians (204979/Z/16/Z); the Edinburgh Clinical Academic Track (ECAT) programme; the National Institute for Health Research, the Wellcome Trust; the MRC; Cancer Research UK; the DHSC; NHS England; the Smilow family; the National Center for Advancing Translational Sciences of the National Institutes of Health (CTSA award number UL1TR001878); the Perelman School of Medicine at the University of Pennsylvania; National Institute on Aging (NIA U01AG009740); the National Institute on Aging (RC2 AG036495, RC4 AG039029); the Common Fund of the Office of the Director of the National Institutes of Health; NCI; NHGRI; NHLBI; NIDA; NIMH; NINDS.Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care or hospitalization after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes-including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)-in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease