Despite the growing demand for hydrogen peroxide it is almost exclusively manufactured by the energy-intensive anthraquinone process. Alternatively, H2O2 can be produced electrochemically via the ...two-electron oxygen reduction reaction, although the performance of the state-of-the-art electrocatalysts is insufficient to meet the demands for industrialization. Interestingly, guided by first-principles calculations, we found that the catalytic properties of the Co–N4 moiety can be tailored by fine-tuning its surrounding atomic configuration to resemble the structure-dependent catalytic properties of metalloenzymes. Using this principle, we designed and synthesized a single-atom electrocatalyst that comprises an optimized Co–N4 moiety incorporated in nitrogen-doped graphene for H2O2 production and exhibits a kinetic current density of 2.8 mA cm−2 (at 0.65 V versus the reversible hydrogen electrode) and a mass activity of 155 A g−1 (at 0.65 V versus the reversible hydrogen electrode) with negligible activity loss over 110 hours.Producing H2O2 electrochemically currently use electrocatalysts that are insufficient to meet the demands for industrialization. A single-atom electrocatalyst with an optimized Co–N4 moiety incorporated in nitrogen-doped graphene is shown to exhibit enhanced performance for H2O2 production.
...to deaths during the compensated stage, which are largely due to cardiovascular disease, malignancy, and renal disease, deaths during the decompensated stage result from hepatic and extrahepatic ...organ failure. 1 The clinical course of LC is not linear but punctuated with episode(s) of acute deterioration (called AD, acute decompensation). ...low physical performance is considered a predictor for poor outcomes; thus, such measures are useful to classify the severity of sarcopenia. 4 In patients with LC, factors contributing to sarcopenia in an interrelated manner could be categorized as (1) malnutrition (including inadequate intake and uptake; a state of ‘accelerated starvation’), (2) cirrhosis-related (including synthetic dysfunction; hyperammonaemia, which is myotoxic; anabolic resistance), (3) other systems-related (including systemic inflammation; gut dysbiosis and altered gut permeability; metabolic dysregulation), (4) physical inactivity, and (5) environmental/organizational factors. 6 Unlike the geriatric literature, computed tomography (CT) imaging is currently the gold standard for the assessment of muscle mass in cirrhosis. 6,7 When abdominal CT imaging is performed for clinical reasons, muscle mass measurement can be obtained using quantitative morphomics software as the skeletal muscle mass (SMI) at the third lumbar vertebra (L3). In a Canadian study of 669 cirrhotic patients who were evaluated for LT, Montano-Loza et al. reported that the modification of MELD to include sarcopenia (MELD-sarcopenia) is associated with an improvement in the prediction of mortality in patients with cirrhosis, and the observed benefit of modifying MELD to include sarcopenia was greatest in patients with low MELD scores, who are traditionally deemed to have a low risk of death. 15 Similarly, in a Korean study, although cirrhotic patients with sarcopenia had higher MELD scores, sarcopenia was associated with mortality in compensated and early decompensated cirrhosis. 16 Kang et al. showed that the impact of sarcopenia was stronger in patients with low MELD scores (MELD score < 15), Child–Pugh class A/B, and hepatic venous pressure gradient (HVPG) < 20 mmHg. In a recent study of US veterans, Shah et al. demonstrated that frailty increases the likelihood of ACLF hospitalization among patients with cirrhosis, but it does not impact short-term ACLF mortality. 18 These findings may be because once ACLF has been triggered, the most critical factor might be organ dysfunction, which drives mortality, as opposed to risk factors leading to inciting ACLF events, such as sarcopenia and frailty. ...there might be a possibility of errors in determining the independent effect of sarcopenia on mortality in patients with Child–Pugh class C or high MELD, who are prone to develop ACLF if they are not analysed separately.
This study investigates the role of content and noncontent cues of tourism information quality in forming users’ destination image in social media. Empirical analysis based on data collected from ...Sina Weibo users suggests that several content cues and web page design as a noncontent cue are positively related with cognitive and affective images, which lead to a conative image. This study contributes to the body of knowledge on the role of tourism information quality in social media by providing empirical evidence on destination image formation. It also helps tourism managers build their marketing strategies to attract more tourists through social media.
More than half of the adult population worldwide is overweight or obese, while excess adiposity has been linked to chronic low-grade inflammation, contributing to the development of chronic diseases. ...Recent studies have showed that diet-induced alterations to the gut microbiota composition play a pivotal role in the development of obesity. However, the cause-effect relationship between obesity and gut microbiota composition is not yet fully understood. In this study, we investigated the short-term responses of gut microbiota composition to diets with different fat contents and their associations with inflammatory biomarkers.
Sixty male C57BL/6 J mice were fed a normal diet (ND; 15% fat) or a high-fat diet (HFD; 45% fat) for 10 or 20 weeks. The relative proportion of the phylum Actinobacteria was elevated by the HFD and was positively associated with body weight and proinflammatory cytokines including TNF-α, IL-1β, and IL-6. The proportion of the phylum Firmicutes increased with aging and was also positively correlated with proinflammatory cytokines. The proportions of Actinobacteria and Firmicutes were inversely associated with tight junction proteins claudin-1 and E-cadherin, respectively. The proportions of the class Clostridia and the family Ruminococcaceae within the phylum Firmicutes were affected by both diet and age. In addition, the proportions of the phylum Bacteroidetes, the family Bacteroidaceae, and the genus Bacteroides decreased with aging and were inversely correlated with colonic proinflammatory cytokines representing a positive association with tight junction proteins.
Host age and dietary fat intake are important elements that induce proportional changes in gut microbiota, and these changes are also associated with systemic inflammation. This study provides evidence that diet affects the gut microbiota composition within a short period of time.
Single‐atom M‒N‒C catalysts have attracted tremendous attention for their application to electrocatalysis. Nitrogen‐coordinated mononuclear metal moieties (MNx moities) are bio‐inspired active sites ...that are analogous to various metal‐porphyrin cofactors. Given that the functions of metal‐porphyrin cofactors are highly dependent on the local coordination environments around the mononuclear active site, engineering MNx active sites in heterogeneous M‒N‒C catalysts would provide an additional degree of freedom for boosting their electrocatalytic activity. This work presents a local coordination structure modification of FeN4 moieties via morphological engineering of graphene support. Introducing highly wrinkled structure in graphene matrix induces nonplanar distortion of FeN4 moieties, resulting in the modification of electronic structure of mononuclear Fe. Electrochemical analysis combined with first‐principles calculations reveal that enhanced electrocatalytic lithium polysulfide conversion, especially the Li2S redox step, is attributed to the local structure modified FeN4 active sites, while increased specific surface area also contributes to improved performance at low C‐rates. Owing to the synergistic combination of atomic‐level modified FeN4 active sites and morphological advantage of graphene support, Fe‒N‒C catalysts with wrinkled graphene morphology show superior lithium–sulfur battery performance at both low and high C‐rates (particularly 915.9 mAh g−1 at 5 C) with promising cycling stability.
Atomic‐level engineering of MNx active sites is a desirable strategy to enhance and fine‐tune electrocatalytic performance of M‒N‒C catalysts. FeN4 active sites on wrinkled graphene support exhibits different structural and electronic properties compared to square‐planar FeN4 moieties. The synergistic combination of modified FeN4 active sites and morphological advantage of wrinkled graphene support improves the electrocatalytic performance for lithium–sulfur conversion chemistry.
Flammulina velutipes is a fungus with health and medicinal benefits that has been used for consumption and cultivation in East Asia. F. velutipes is also known to degrade lignocellulose and produce ...ethanol. The overlapping interests of mushroom production and wood bioconversion make F. velutipes an attractive new model for fungal wood related studies. Here, we present the complete sequence of the F. velutipes genome. This is the first sequenced genome for a commercially produced edible mushroom that also degrades wood. The 35.6-Mb genome contained 12,218 predicted protein-encoding genes and 287 tRNA genes assembled into 11 scaffolds corresponding with the 11 chromosomes of strain KACC42780. The 88.4-kb mitochondrial genome contained 35 genes. Well-developed wood degrading machinery with strong potential for lignin degradation (69 auxiliary activities, formerly FOLymes) and carbohydrate degradation (392 CAZymes), along with 58 alcohol dehydrogenase genes were highly expressed in the mycelium, demonstrating the potential application of this organism to bioethanol production. Thus, the newly uncovered wood degrading capacity and sequential nature of this process in F. velutipes, offer interesting possibilities for more detailed studies on either lignin or (hemi-) cellulose degradation in complex wood substrates. The mutual interest in wood degradation by the mushroom industry and (ligno-)cellulose biomass related industries further increase the significance of F. velutipes as a new model.
Polymeric microcomponents are widely used in microelectromechanical systems (MEMS) and lab-on-a-chip devices, but they suffer from the lack of complex motion, effective addressability and precise ...shape control. To address these needs, we fabricated polymeric nanocomposite microactuators driven by programmable heterogeneous magnetic anisotropy. Spatially modulated photopatterning was applied in a shape-independent manner to microactuator components by successive confinement of self-assembled magnetic nanoparticles in a fixed polymer matrix. By freely programming the rotational axis of each component, we demonstrate that the polymeric microactuators can undergo predesigned, complex two- and three-dimensional motion.
Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most ...advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including "safe harboring" techniques shown in other organisms.
Colorectal cancer is one of the most common causes ofcancer morbidity both in men and in women. However,females over 65 years old show higher mortality andlower 5-year survival rate of colorectal ...cancer comparedto their age-matched male counterparts. The objectiveof this review is to suggest gender-based innovationsto improve colorectal cancer outcomes in females.Women have a higher risk of developing right-sided（proximal） colon cancer than men, which is associatedwith more aggressive form of neoplasia compared toleft-sided （distal） colon cancer. Despite differencesin tumor location between women and men, most ofscientific researchers do not consider sex specificityfor study design and interpretation. Also, colorectalcancer screening guidelines do not distinguish femalesfrom male, which may explain the higher frequencyof more advanced neoplasia when tumors are firstdetected and false negative results in colonoscopyin females. Moreover, socio-cultural barriers withinfemales are present to delay screening and diagnosis.Few studies, among studies that included both menand women, have reported sex-specific estimatesof dietary risk factors which are crucial to establishcancer prevention guidelines despite sex- and genderassociateddifferences in nutrient metabolism anddietary practices. Furthermore, anti-cancer drug usefor colorectal cancer treatment can cause toxicityto the reproductive system, and gender-specificrecurrence and survival rates are reported. Therefore,by understanding sex- and gender-related biologicaland socio-cultural differences in colorectal cancer risk,gender-specific strategies for screening, treatment andprevention protocols can be established to reduce themortality and improve the quality of life.
The effect of porous structures on the electrocatalytic activity of N-doped carbon is studied by using electrochemical analysis techniques and the result is applied to synthesize highly active and ...stable Fe–N–C catalyst for oxygen reduction reaction (ORR). We developed synthetic procedures to prepare three types of N-doped carbon model catalysts that are designed for systematic comparison of the porous structures. The difference in their catalytic activity is investigated in relation to the surface area and the electrochemical parameters. We found that macro- and mesoporous structures contribute to different stages of the reaction kinetics. The catalytic activity is further enhanced by loading the optimized amount of Fe to prepare Fe–N–C catalyst. In both N-doped carbon and Fe–N–C catalysts, the hierarchical porous structure improved electrocatalytic performance in acidic and alkaline media. The optimized catalyst exhibits one of the best ORR performance in alkaline medium with excellent long-term stability in anion exchange membrane fuel cell and accelerated durability test. Our study establishes a basis for rationale design of the porous carbon structure for electrocatalytic applications.
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