265 research outputs found
Dramatic Increases of Soil Microbial Functional Gene Diversity at the Treeline Ecotone of Changbai Mountain.
The elevational and latitudinal diversity patterns of microbial taxa have attracted great attention in the past decade. Recently, the distribution of functional attributes has been in the spotlight. Here, we report a study profiling soil microbial communities along an elevation gradient (500-2200 m) on Changbai Mountain. Using a comprehensive functional gene microarray (GeoChip 5.0), we found that microbial functional gene richness exhibited a dramatic increase at the treeline ecotone, but the bacterial taxonomic and phylogenetic diversity based on 16S rRNA gene sequencing did not exhibit such a similar trend. However, the β-diversity (compositional dissimilarity among sites) pattern for both bacterial taxa and functional genes was similar, showing significant elevational distance-decay patterns which presented increased dissimilarity with elevation. The bacterial taxonomic diversity/structure was strongly influenced by soil pH, while the functional gene diversity/structure was significantly correlated with soil dissolved organic carbon (DOC). This finding highlights that soil DOC may be a good predictor in determining the elevational distribution of microbial functional genes. The finding of significant shifts in functional gene diversity at the treeline ecotone could also provide valuable information for predicting the responses of microbial functions to climate change
Genetic Evolution and Molecular Selection of the HE Gene of Influenza C Virus
Influenza C virus (ICV) was first identified in humans and swine, but recently also in cattle, indicating a wider host range and potential threat to both the livestock industry and public health than was originally anticipated. The ICV hemagglutinin-esterase (HE) glycoprotein has multiple functions in the viral replication cycle and is the major determinant of antigenicity. Here, we developed a comparative approach integrating genetics, molecular selection analysis, and structural biology to identify the codon usage and adaptive evolution of ICV. We show that ICV can be classified into six lineages, consistent with previous studies. The HE gene has a low codon usage bias, which may facilitate ICV replication by reducing competition during evolution. Natural selection, dinucleotide composition, and mutation pressure shape the codon usage patterns of the ICV HE gene, with natural selection being the most important factor. Codon adaptation index (CAI) and relative codon deoptimization index (RCDI) analysis revealed that the greatest adaption of ICV was to humans, followed by cattle and swine. Additionally, similarity index (SiD) analysis revealed that swine exerted a stronger evolutionary pressure on ICV than humans, which is considered the primary reservoir. Furthermore, a similar tendency was also observed in the M gene. Of note, we found HE residues 176, 194, and 198 to be under positive selection, which may be the result of escape from antibody responses. Our study provides useful information on the genetic evolution of ICV from a new perspective that can help devise prevention and control strategies
Outcomes of single- vs two-stage primary joint arthroplasty for septic arthritis: a systematic review and meta-analysis
Purpose: Septic arthritis (SA) is an intra-articular infection caused by purulent bacteria and the only effective method is surgical intervention. Two-stage arthroplasty is considered the gold standard treatment for SA, but recent studies have found that single-stage arthroplasty can achieve the same efficacy as two-stage arthroplasty. This study aimed to compare the efficacy of single- vs two-stage arthroplasty in the treatment of (acute or quiescent) SA.
Methods: The review process was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched the PubMed, EMBASE, Medline, and Cochrane Library databases to identify all literature on the treatment of SA using single- and two-stage arthroplasty from the date of database inception to November 10, 2022. Data on reinfection rates were expressed as odds ratios and 95% CIs.
Results: Seven retrospective studies with a total of 413 patients were included. Pooled analysis showed no difference in the reinfection rate between single- and two-stage arthroplasty. Subgroup analysis found no difference between the single- and two-stage arthroplasty groups in the incidence of purulent infection of the hip and knee. Cumulative meta-analysis showed gradual stabilization of outcomes.
Conclusions: Based on our meta-analysis of available retrospective studies, we found no significant difference in reinfection rates between single- and two-stage arthroplasty for SA. Further prospective cohort studies are needed to confirm our results, although our meta-analysis provides important insights into the current literature on this topic
Recruitment of Atg9 to the preautophagosomal structure by Atg11 is essential for selective autophagy in budding yeast
Autophagy is a conserved degradative pathway that is induced in response to various stress and developmental conditions in eukaryotic cells. It allows the elimination of cytosolic proteins and organelles in the lysosome/vacuole. In the yeast Saccharomyces cerevisiae, the integral membrane protein Atg9 (autophagy-related protein 9) cycles between mitochondria and the preautophagosomal structure (PAS), the nucleating site for formation of the sequestering vesicle, suggesting a role in supplying membrane for vesicle formation and/or expansion during autophagy. To better understand the mechanisms involved in Atg9 cycling, we performed a yeast two-hybrid–based screen and identified a peripheral membrane protein, Atg11, that interacts with Atg9. We show that Atg11 governs Atg9 cycling through the PAS during specific autophagy. We also demonstrate that the integrity of the actin cytoskeleton is essential for correct targeting of Atg11 to the PAS. We propose that a pool of Atg11 mediates the anterograde transport of Atg9 to the PAS that is dependent on the actin cytoskeleton during yeast vegetative growth
MOF-derived ultrathin cobalt molybdenum phosphide nanosheets for efficient electrochemical overall water splitting
Altres ajuts: IREC is funded by the CERCA Programme/Generalitat de Catalunya. ICN2 is funded by the CERCA Programme/Generalitat de Catalunya.The development of high-performance and cost-effective earth-abundant transition metal-based electrocatalysts is of major interest for several key energy technologies, including water splitting. Herein, we report the synthesis of ultrathin CoMoP nanosheets through a simple ion etching and phosphorization method. The obtained catalyst exhibits outstanding electrocatalytic activity and stability towards oxygen and hydrogen evolution reactions (OER and HER), with overpotentials down to 273 and 89 mV at 10 mA cm −2, respectively. The produced CoMoP nanosheets are also characterized by very small Tafel slopes, 54.9 and 69.7 mV dec −1 for OER and HER, respectively. When used as both cathode and anode electrocatalyst in the overall water splitting reaction, CoMoP-based cells require just 1.56 V to reach 10 mA cm −2 in alkaline media. This outstanding performance is attributed to the proper composition, weak crystallinity and two-dimensional nanosheet structure of the electrocatalyst
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Thermoelectric Properties of Novel Semimetals: A Case Study of YbMnSb2
The emerging class of topological materials provides a platform to engineer exotic electronic structures for a variety of applications. As complex band structures and Fermi surfaces can directly benefit thermoelectric performance it is important to identify the role of featured topological bands in thermoelectrics particularly when there are coexisting classic regular bands. In this work, the contribution of Dirac bands to thermoelectric performance and their ability to concurrently achieve large thermopower and low resistivity in novel semimetals is investigated. By examining the YbMnSb2 nodal line semimetal as an example, the Dirac bands appear to provide a low resistivity along the direction in which they are highly dispersive. Moreover, because of the regular-band-provided density of states, a large Seebeck coefficient over 160 µV K−1 at 300 K is achieved in both directions, which is very high for a semimetal with high carrier concentration. The combined highly dispersive Dirac and regular bands lead to ten times increase in power factor, reaching a value of 2.1 mW m−1 K−2 at 300 K. The present work highlights the potential of such novel semimetals for unusual electronic transport properties and guides strategies towards high thermoelectric performance. © 2020 The Authors. Advanced Materials published by Wiley-VCH Gmb
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