Nano-Architecture of nitrogen-doped graphene films synthesized from a solid CN source

New synthesis routes to tailor graphene properties by controlling the concentration and chemical configuration of dopants show great promise. Herein we report the direct reproducible synthesis of 2-3% nitrogen-doped ‘few-layer’ graphene from a solid state nitrogen carbide a-C:N source synthesized by femtosecond pulsed laser ablation. Analytical investigations, including synchrotron facilities, made it possible to identify the configuration and chemistry of the nitrogen-doped graphene films. Auger mapping successfully quantified the 2D distribution of the number of graphene layers over the surface, and hence offers a new original way to probe the architecture of graphene sheets. The films mainly consist in a Bernal ABA stacking three-layer architecture, with a layer number distribution ranging from 2 to 6. Nitrogen doping affects the charge carrier distribution but has no significant effects on the number of lattice defects or disorders, compared to undoped graphene synthetized in similar conditions. Pyridinic, quaternary and pyrrolic nitrogen are the dominant chemical configurations, pyridinic N being preponderant at the scale of the film architecture. This work opens highly promising perspectives for the development of self-organized nitrogen-doped graphene materials, as synthetized from solid carbon nitride, with various functionalities, and for the characterization of 2D materials using a significant new methodology

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

2010: A library odyssey

The paper aims to provide an overview of how The University of Queensland Library has prepared itself for the changes and challenges of the future and positioned itself in readiness for some of the forecast mega trends of 2020. The experience of the complete makeover of the UQ Library is used as a case study to demonstrate how a library has responded to the challenges from planning to the implementation stages

Effects of Static Heat and Dynamic Current on Al/Zn∙Cu/Sn Solder/Ag Interfaces of Sn Photovoltaic Al-Ribbon Modules

This present study applied Cu∙Zn/Al ribbon in place of a traditional Cu ribbon to a photovoltaic (PV) ribbon. A hot-dipped and an electroplated Sn PV ribbon reflowed onto an Ag electrode on a Si solar cell and estimated the feasibility of the tested module (Ag/Solder/Cu∙Zn/Al). After bias-aging, a bias-induced thermal diffusion and an electromigration promoted the growth of intermetallic compounds (IMCs) (Cu6Sn5, Ag3Sn). To simulate a photo-generated current in the series connection of solar cells, an electron with Ag-direction (electron flows from Ag to Al) and Al-direction (electron flows from Al to Ag) was passed through the Al/Zn∙Cu/Solder/Ag structure to clarify the growth mechanism of IMCs. An increase in resistance of the Ag-direction-biased module was higher than that of the Al-direction biased one due to the intense growth of Cu6Sn5 and Ag3Sn IMCs. The coated solder of the electroplated PV ribbon was less than that of the hot-dipped one, and thus decreased the growth reaction of IMCs and the cost of PV ribbon

The Relationship of Fracture Mechanism between High Temperature Tensile Mechanical Properties and Particle Erosion Resistance of Selective Laser Melting Ti-6Al-4V Alloy

In this study, selective laser melting (SLM) Ti-6Al-4V is subjected to heat treatment for 4 h at 400 °C, 600 °C, and 800 °C, followed by air cooling. After heat treatment at 400 °C and 600 °C, the ductility was lower (strength increased). This was could be for two reasons: (1) high temperature tensile properties, and (2) particle erosion wear induced phase transformation. Finally, the particle erosion rates of as-SLM Ti-6Al-4V and heat treatment for 4 h at 800 °C (labeled 800-AC) were investigated and compared; the lamellar α + β phases in 800-AC are difficult to destroy with erosion particles, resulting in the erosion resistance of 800-AC being higher than that of the martensitic α’ needles in the as-SLM Ti-6Al-4V at all impact angles (even the hardness of the 800-AC specimen was lower). The as-SLM Ti-6Al-4V alloy needs heat treatment to have better wear resistance

Weibull Statistics for Evaluating Failure Behaviors and Joining Reliability of Friction Stir Spot Welded 5052 Aluminum Alloy

Friction stir spot welding (FSSW) was applied to make lap-joints of 5052 rolled (5052-R) aluminum alloys. The resulting microstructural observation, microhardness, tensile shear failure load and failure morphologies are reported, including a brief look into failure behaviors in the present study. The metallurgical bonded TMAZ region with a plastic metal flow is obviously created around the probe, and the microhardness is significantly increased at the TMAZ region for FSSW-joined 5052 aluminum alloys. The FSSW lap-joints with an obvious metallurgical bonded TMAZ region generally display a higher failure load and ductile failure morphologies with dimples fracture. In addition, the failure load of FSSW lap-joints was increased with increasing the probe penetration depth and the welding time. Based on the data fluctuation of tensile shear failure load, the Weibull model provided a statistical analysis method for assessing the minimum failure, the failure mechanism and the joining reliability for the FSSW lap-joints. Through the statistical analysis of the Weibull distribution function, FSSW-joined aluminum alloys with a wear-out failure model are recognized as reliable lap-joints for further engineering application

Identification of loci controlling adaptation in Chinese soya bean landraces via a combination of conventional and bioclimatic GWAS

Landraces often contain genetic diversity that has been lost in modern cultivars, including alleles that confer enhanced local adaptation. To comprehensively identify loci associated with adaptive traits in soya bean landraces, for example flowering time, a population of 1938 diverse landraces and 97 accessions of the wild progenitor of cultivated soya bean, Glycine soja was genotyped using tGBS. Based on 99 085 high-quality SNPs, landraces were classified into three subpopulations which exhibit geographical genetic differentiation. Clustering was inferred from STRUCTURE, principal component analyses and neighbour-joining tree analyses. Using phenotypic data collected at two locations separated by 10 degrees of latitude, 17 trait-associated SNPs (TASs) for flowering time were identified, including a stable locus Chr12:5914898 and previously undetected candidate QTL/genes for flowering time in the vicinity of the previously cloned flowering genes, E1 and E2. Using passport data associated with the collection sites of the landraces, 27 SNPs associated with adaptation to three bioclimatic variables (temperature, daylength, and precipitation) were identified. A series of candidate flowering genes were detected within linkage disequilibrium (LD) blocks surrounding 12 bioclimatic TASs. Nine of these TASs exhibit significant differences in flowering time between alleles within one or more of the three individual sub-populations. Signals of selection during domestication and/or subsequent landrace diversification and adaptation were detected at 38 of the 44 flowering and bioclimatic TASs. Hence, this study lays the groundwork to begin breeding for novel environments predicted to arise following global climate change

Heart failure and depression: A perspective from bibliometric analysis

Background: Depression commonly occurs in heart failure patients, and negatively influences quality of life and disease prognosis. This study explored heart failure and depression-related research from a bibliometric perspective. Methods: Relevant publications were searched on June 24, 2022. The Bibliometrix package in R was used to conduct quantitative analyses including the trends in publications, and related countries, articles, authors and keywords. VOSviewer software was used to conduct the visualization map on co-word, co-author, and institution co-authorship analyses. CiteSpace software was used to illustrate the top keywords with citation burst. Results: A total of 8,221 publications in the heart failure and depression related research field were published between 1983 and 2022. In this field, the United States had the most publications (N = 3,013; 36.65%) and highest total citation (N = 149, 376), followed by China, Germany, Italy and Japan. Author Moser and Duke University were the most productive author and institution, respectively. Circulation is the most influential journal. Apart from “heart failure” and “depression,” “quality of life,” “mortality” and “myocardial infarction” were the most frequently used keywords in this research area; whereas more recently, “self care” and “anxiety” have been used more frequently. Conclusion: This bibliometric analysis showed a rapid growth of research related to heart failure and depression from 1989 to 2021, which was mostly led by North America and Europe. Future directions in this research area include issues concerning self-care and anxiety about heart failure. As most of the existing literature were published in English, publications in other languages should be examined in the future

Randomized controlled trial of transcutaneous electrical nerve stimulation for pain relief during transvaginal oocyte retrieval using conscious sedation: study protocol for a randomized controlled trial

Abstract Background Transvaginal oocytes retrieval is an essential step in in-vitro fertilization treatment. There are different pain relief methods, but none has been shown to be superior than the others. Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological and non-invasive pain relief method. This study aims to compare the pain levels experienced by the women using the conscious sedation and those who had TENS in addition to conscious sedation. Methods and analysis This is a double-blinded randomized trial that will be carried out in a university-assisted conception unit. Women who will undergo oocyte retrieval under conscious sedation will be recruited. After randomization, women will be allocated to either the active TENS group or placebo TENS group (the TENS machine will not emit active impulse), in addition to the paracervical block and conscious sedation. The primary outcome is pain levels of women during the retrieval assessed by the visual analog scale. Secondary outcomes include satisfaction of women and postoperative side effects. Discussion TENS is an effective non-pharmacological and non-invasive method for pain relief in a number of clinical conditions. Both women and assisted conception unit can benefit if the addition of non-invasive, simple, and low-cost TENS application is proven to be superior than using conscious sedation and paracervical block alone. Trial registration ClinicalTrials.gov, NCT03472430. Registered on 3 May 2018