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The non-racemic enantiomers may exist with very small %ee values, which formed by some asymmetric factors (such as symmetry breaking) during their synthesis in the prebiotic pool in the absence of other chiral sources. We now conclude a mathematic formula by concerning the organic reaction principles. We found that the tiny %ee (%ee1) values of non-racemic enantiomers can be enhanced to a reasonable large %ee values (%ee2) after the non-racemic enantiomers react with bis-functional group reagents (such as oxalaldehyde). Theoretically, if the %ee1 is extremely small, the enhancement/amplification multiples (%ee2/%ee1) should increase greatly. The is necessary to enrich the %ee values in prebiotic pool for the chiral compounds (such as L-amino acids) with very small %ee values. Finally, about 1% of L-tryptophan methyl ester （L-TME） was used to react with CHOCHO, and the %ee2 of the L-TME remained in solution increased to 3.4%. The largest amplification multiple is 1.9 (from 6.1% of %ee1 to enrich to 11.7% (%ee2)); The largest increasement of the %ee (Δ%ee=%ee2-%ee1) is 12.3% (from 44.2% to 56.5%).

Abstract Background Ectromelia virus (ECTV) is the causative agent of mousepox in mice. In the past century, ECTV was a serious threat to laboratory mouse colonies worldwide. Recombinase polymerase amplification (RPA), which is widely used in virus detection, is an isothermal amplification method. Results In this study, a probe-based RPA detection method was established for rapid and sensitive detection of ECTV.Primers were designed for the highly conserved region of the crmD gene, the main core protein of recessive poxvirus, and standard plasmids were constructed. The lowest detection limit of the ECTV RT- RPA assay was 100 copies of DNA mol-ecules per reaction. In addition, the method showed high specificity and did not cross-react with other common mouse viruses.Therefore, the practicability of the RPA method in the field was confirmed by the detection of 135 clinical samples. The real-time RPA assay was very similar to the ECTV real-time PCR assay, with 100% agreement. Conclusions In conclusion, this RPA assay offers a novel alternative for the simple, sensitive, and specific identification of ECTV, especially in low-resource settings.

Abstract Background Goose astrovirus (GoAstV) is an important pathogen that causes joint and visceral gout in goslings. It has been circulating in many provinces of China since 2017. Goose astrovirus genotypes 2 (GoAstV-2) is the main epidemic strain, and its high morbidity and mortality have caused huge economic losses to the goose industry. An accurate point-of-care detection for GoAstV-2 is of great significance. In this study, we developed a real-time reverse transcription recombinase polymerase amplification (RT-RPA) method for the on-site detection of GoAstV-2 infection. Results The real-time RT-RPA reaction was carried out at a constant temperature of 39 °C, and the entire detection time from nucleic acid preparation to the end of amplification was only 25 min using the portable device. The results of a specificity analysis showed that no cross-reaction was observed with other related pathogens. The detection limit of the assay was 100 RNA copies/μL. The low coefficient of variation value indicated excellent repeatability. We used 270 clinical samples to evaluate the performance of our established method, the positive concordance rates with RT-qPCR were 99.6%, and the linear regression analysis revealed a strong correlation. Conclusions The established real-time RT-RPA assay showed high rapidity, specificity and sensitivity, which can be widely applied in the laboratory, field and especially in the resource-limited settings for GoAstV-2 point-of-care diagnosis.

Abstract Backscatter communication relies on passive reflections of the existing radio frequency (RF) signals, making it suitable for low-power and low-complexity communication in IoT applications. However, the performance of existing systems severely degrades in real-life environments, due to irregular “on” and “off” states of ambient signals like WiFi, which are not controllable. In this paper, we propose a joint coding and framing scheme for the backscattering physical layer to fight against the off-state in the excitation signal. We first design transmission schemes including both the Reed-Solomon (RS) codes and the frame structure, to correct the burst error caused by the off states. In order to implement the codes at the resource-constrained tag, we design a look-up table for the encoding process. We prototype our system NuWa that could efficiently backscatter with uncontrolled traffics generated randomly. We demonstrate that NuWa could achieve a 1 Mbps transmission throughput when the tag is over 1 m away from the receiver in high traffic load and 150 kbps in low traffic load. Finally, we evaluate the throughput with respect to the distance change between the tag and the receiver, and 950 kbps is achieved at a distance of $$6\,m$$ 6 m .

With the rapid development of the internet of things (IoT) era, IoT devices may face limitations in battery capacity and computational capability. Simultaneous wireless information and power transfer (SWIPT) and mobile edge computing (MEC) have emerged as promising technologies to address these challenges. Due to wireless channel fading and susceptibility to obstacles, this paper introduces intelligent reflecting surfaces (IRS) to enhance the spectral and energy efficiency of wireless networks. We propose a system model for IRS-assisted uplink offloading computation, downlink offloading computation results, and simultaneous energy transfer. Considering constraints such as IRS phase shifts, latency, energy harvesting, and offloading transmit power, we jointly optimize the CPU frequency of IoT devices, offloading transmit power, local computation workload, power splitting (PS) ratio, and IRS phase shifts. This establishes a multi-variate coupled nonlinear problem aimed at minimizing IoT devices energy consumption. We design an effective alternating optimization (AO) iterative algorithm based on block coordinate descent, and utilize closed-form solutions, Dinkelbach-based Lagrange dual method, and semidefinite relaxation (SDR) method to minimize IoT devices energy consumption. Simulation results demonstrate that the proposed scheme achieves lower energy consumption compared to other resource allocation strategies.

Grain size is a primary determinant of grain weight, which is one of the three essential components of rice grain yield. Mining the genes that control grain size plays an important role in analyzing the regulation mechanism of grain size and improving grain appearance quality. In this study, two closely linked quantitative trait loci (QTL) controlling grain size, were dissected and fine-mapped in a 515.6-kb region on the long arm of chromosome 10 by using six near isogenic line populations. One of them, qGS10.2, which controlled 1000 grain weight (TGW) and grain width (GW), was delimited into a 68.1-kb region containing 14 annotated genes. The Teqing allele increased TGW and GW by 0.17 g and 0.011 mm with the R2 of 12.7% and 11.8%, respectively. The other one, qGL10.2, which controlled grain length (GL), was delimited into a 137.3-kb region containing 22 annotated genes. The IRBB52 allele increased GL by 0.018 mm with the R2 of 6.8%. Identification of these two QTL provides candidate regions for cloning of grain size genes.

Abstract Lamellar graphene oxide (GO) membranes have gained substantial interest for molecular separation processes. However, GO membranes have shown inefficient separation performance levels due to their possession of sufficient functional groups that lead to swelling under applied hydraulic pressure. Herein, we demonstrate a highly stable and ultrafast filtrable graphene oxide-boron nitride (GOBN) hybrid membrane by incorporating boron nitride (BN) nanosheets into a GO membrane to restrict swelling and provide efficient hydraulic pressure separation characteristics. This new heterostructure retains the GOBN membrane microstructure and provides more nanochannels around the incorporation sites due to the small size of BN nanosheets; this phenomenon increases the permeance to 1310 Lm−2h−1bar−1, which is nearly six times higher than that of the pure GO membrane, with a high rejection reaching 99.2% for aqueous organic dyes. More importantly, the GOBN hybrid membrane shows an impressive permeance and dye molecule rejection performance characteristic across a range of organic solvents, such as methanol, ethanol, and isopropyl alcohol; the performance characteristics are better than those for the GO membrane. Our GOBN membrane with a stable microstructure opens opportunities for developing a high-performance multiple solvent nanofiltration membrane that surpasses the permeability-selectivity trade-off.

Abstract Background Swine acute diarrhea syndrome coronavirus (SADS-CoV) causes acute vomiting and diarrhea in piglets, leading to significant financial losses for the pig industry. Recombinase polymerase amplification (RPA) is a rapid nucleic acid amplification technology used under constant temperature conditions. The study established a real-time reverse transcription (RT)-RPA assay for early diagnosis of SADS-CoV. Results The detection limit of the real-time RT-RPA was 74 copies/µL of SADS-CoV genomic standard recombinant plasmid in 95% of cases. The assay was performed in less than 30 min and no cross-reactions were observed with eight other common viruses that affect swine, including classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), pseudo rabies virus (PRV), swine influenza virus (SIV), seneca valley virus (SVA), transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV). The coefficient of variation (C.V.) values of the two standards dilutions and three positive clinical sample ranged from 2.95% to 4.71%. A total of 72 clinical fecal samples from swine with diarrheal symptoms were analyzed with the developed RT-RPA and quantitative RT-PCR. There was 98.61% agreement between the RT-RPA and the quantitative real-time PCR results. Conclusions These results indicated that the developed RT-RPA assay had good specificity, sensitivity, stability and repeatability. The study successfully established a broadly reactive RT-RPA assay for SADS-CoV detection.

Nanoparticle-assisted polymerase chain reaction (nanoPCR) is a novel method for the rapid detection of pathogens. A sensitive and specific multiple nanoPCR assay was developed for simultaneous detection of avian leucosis virus (ALV) subgroups A, B and J. In this study, three pairs of primers were designed, based on the conserved region of the gp85 gene. An exploration of the optimal primer concentration and annealing temperature were carried out, for better performance of the nanoPCR assay. According to the results, the multiple nanoPCR assay amplified 336 pb, 625 bp and 167 bp fragments of ALV-A, -B and -J, respectively, and showed no cross-reactivity with irrelevant pathogens, suggesting the excellent specificity of the assay. The constructed standard DNA templates were used to estimate the limit of detection. As shown by the results, the detection limit of the nanoPCR assay was nearly 10 copies/μL. To further evaluate the detection ability of the assay, 186 clinical samples were detected using the nanoPCR assay, among which, 14 samples were confirmed as ALV positive; the results were further confirmed by sequencing. In conclusion, a highly specific and sensitive nanoPCR assay was successfully developed, which could be a useful tool for clinical diagnosis as well as for the discrimination of ALV-A, -B and -J.

Energy system optimization models play an essential role in current decision support on topics including energy security, sustainable development and environmental protection from industrial, regional, national and even global perspective. One of the key energy system optimization models applied in international energy policy is TIMES. The article establishes two basic deterministic TIMES models which cover an energy commodity (coal or gas), a three-step supply curve and an end-use energy service demand. Then we convert the deterministic TIMES models into a stochastic optimization problem with multiple scenarios, and implement the Lagrangian decomposition approach in solving the stochastic programming models. The numerical experiment shows the feasibility of the Lagrangian decomposition algorithm to solve stochastic TIMES models with a small amount of scenarios, and analyze several reasons for non-convergence cases including the choice of step length and initial values of Lagrangian multipliers.

Rice blast is arguably the most devastating fungal disease of rice. Utilization of resistance genes to breed resistant cultivars is one of the most economical and environmentally friendly approaches to combat the disease. Pi25, a major resistance gene conferring broad-spectrum resistance to both leaf and neck blast, is an ideal gene resource to improve the resistance of rice varieties to blast. Recently, several allele-specific markers were developed. However, they were deficiently efficient due to either an additional process of restriction enzyme digestion for cleaved amplified polymorphic sequence (CAPS) markers or the risk of false-positive error in identifying susceptible Tetep allele (Pi25TTP) for PCR-based markers. In this study, based on a conserved single nucleotide polymorphism (SNP) between resistant and susceptible alleles, a tetra-primer amplification refractory mutation system (ARMS)-PCR marker was developed. The new marker, namely Pi25-2687R3, could effectively distinguish the resistant Gumei 2 (GM2) allele (Pi25GM2) and the susceptible allele Pi25TTP. Moreover, a perfect consistency of genotyping was exhibited between Pi25-2687R3 and published CAPS marker CAP3/Hpy 99I. A more accurate genotyping was also displayed compared to the previous PCR-based SNP marker Pi25-2566. Our finding proved that Pi25-2687R3 could achieve the same result as CAP3/Hpy 99I with less workload and cost and could promote the accuracy in the identification of genotypes superior to Pi25-2566. This study provided a quick and reliable functional marker for discriminating Pi25 alleles, which would be a valuable tool for genotypic assay and rice molecular breeding of blast resistance.

With the development of modern industries, environmental pollution has become a serious and urgent issue [...]

BackgroundOsteoporosis (OP) and osteopenia are common bone disorders in old age, and lots of patients suffering from OP or osteopenia need to take antiplatelet agents to treat basic diseases. However, clinical data on the link between osteopenia or OP and antiplatelet agents are limited.MethodsData in this study were collected and screened from the NHANES from 2013 to 2014 and 2017 to 2018. The variables were extracted from interviews and compared between OP or osteopenia participants and normal. The relationship between OP or osteopenia and taking antiplatelet drugs was analyzed by weighted multivariate logistic regressionResultsAfter excluding individuals who were not eligible and had invalid data, we finally identified 894 participants for inclusion in the study. We found a negative association between OP or osteopenia and taking antiplatelet agents (OR = 0.53; 95% CI, 0.33–0.84; p < 0.05). These results did not change on multiple imputations (OR = 0.32, 95% CI, 0.19–0.56; p

Rice is sensitive to high-temperature stress during almost all stages of growth and development. High-temperature stress has become one of the main factors restricting high yield and superior quality of rice. In this study, recombinant inbred lines (RILs) derived from an indica rice cross between two restorer lines were planted in two years. One sowing date was applied in 2019, and four sowing dates were set in 2020 according to the period of local high temperatures in recent years. Two traits closely related to high-temperature tolerance, heading date (HD), and spikelet fertility (SF) were measured. In each trial, the HD showed a bimodal distribution, whereas SF had a continuous and left-skewed distribution. QTL analysis was performed using a high-density bin map. For HD, a total of six QTL were detected. All of them correspond in position to the cloned genes, among which qHD8 in the DTH8/Ghd8 region showed the largest genetic effect. For SF, a total of eight QTL were detected. Five of them, qSF1, qSF2, qSF3.1, qSF3.2, and qSF8, showed high-temperature tolerance and had an important potential in rice breeding.

With the increasing utilization of clean energy, the development and utilization of hydrogen energy has become a research topic of great significance. Cobalt selenide (CS) is an electrocatalyst with great potential for oxygen evolution reaction (OER). In this paper, a nitrogen-doped biomass carbon (1NC@3)-based composite cobalt selenide (CS) heterojunction was prepared via a solvothermal method using kelp as the raw material. Structural, morphological, and electrochemical analyses were conducted to evaluate its performance. The electrochemical test results demonstrate that the overpotential of the CS/1NC@3 catalyst in the OER process was 292 mV, with a Tafel slope of 98.71 mV·dec−1 at a current density of 10 mA·cm−2. The electrochemical performance of the CS/1NC@3 catalyst was further confirmed by theoretical calculations, which revealed that the presence of the biomass carbon substrate enhanced the charge transport speed of the OER process and promoted the OER process. This study provides a promising strategy for the development of efficient electrocatalysts for OER applications.

Catalytic oxidation is regarded as an effective, economical, and practical approach to remove volatile organic compounds such as important air pollutants. CeO2 catalysts with different morphologies exhibit different oxygen vacancies content, which plays a vital role in oxidation reaction. Herein, three distinct morphologies of CeO2 i.e., shuttle (CeO2 (S)), nanorod (CeO2 (R)), and nanoparticle (CeO2 (P)), were successfully fabricated by the SEM and TEM results, and investigated for toluene catalytic oxidation. The various characterizations showed that the CeO2 (S) catalyst exhibited a larger surface area along with higher surface oxygen vacancies in contrast to CeO2 (R) and CeO2 (P), which is responsible for its excellent toluene catalytic oxidation. The 90% toluene conversion temperature at 225 °C over CeO2 (S) was less than that over CeO2 (R) (283 °C) and CeO2 (P) (360 °C). In addition, CeO2 (S) showed a greater reaction rate (14.37 × 10−2 μmol∙g−1∙s−1), TOFov (4.8 × 10−4∙s−1) at 190 °C and lower activation energy value (67.4 kJ/mol). Furthermore, the CeO2 (S) also displayed good recyclability, long-term activity stability, and good tolerance to water. As a result, CeO2 (S) is considered a good candidate to remove toluene.

Rice is one of the most important food crops in the world. However, stable rice production is constrained by various diseases, in particular rice blast, sheath blight, bacterial blight, and virus diseases. Breeding and cultivation of resistant rice varieties is the most effective method to control the infection of pathogens. Exploitation and utilization of the genetic determinants of broad-spectrum resistance represent a desired way to improve the resistance of susceptible rice varieties. Recently, researchers have focused on the identification of rice broad-spectrum disease resistance genes, which include R genes, defense-regulator genes, and quantitative trait loci (QTL) against two or more pathogen species or many isolates of the same pathogen species. The cloning of broad-spectrum disease resistance genes and understanding their underlying mechanisms not only provide new genetic resources for breeding broad-spectrum rice varieties, but also promote the development of new disease resistance breeding strategies, such as editing susceptibility and executor R genes. In this review, the most recent advances in the identification of broad-spectrum disease resistance genes in rice and their application in crop improvement through biotechnology approaches during the past 10 years are summarized.

BACKGROUND: Older people have higher risk of experiencing medication-related problems (MRPs), leading to increased morbidity, health care use, and mortality. Few studies have examined the pathway between limited English proficiency (LEP) among older people and health service use through MRPs. OBJECTiVE: This study aimed to explore the association of LEP among Latino older people with MRPs and their relationship to emergency room (ER) visits. METHODS: Researchers used secondary enrollment data from a community medication program for older people (N = 180). Researchers conducted linear regression to examine the relationship between ethnicity/English proficiency and MRPs, and logistic regression to explore the association between MRPs and ER visits. Generalized structural equation modeling (GSEM) with bootstrapping was used to test the indirect effect between LEP Latino through MRPs to ER visits. RESULTS: The sample included 70% non-Latino participants, 12% English-speaking Latinos, and 18% LEP Latinos. Analysis LEP Latinos were associated with having 3.4 more MRPs than non-Latino participants, after controlling for covariates. Additionally, each additional MRP was associated with a 10% increased probability of having an ER visit. The GSEM results illustrated there was a significant indirect effect between LEP through MRPs to ER visits (β = 0.27, 95% CI 0.07-0.61). CONCLUSiON: Though LEP was not directly related to increased ER visits, it may have inhibited the ability of Latinos to read and understand medication instructions, contributing to their elevated risk of experiencing MRPs, thus indirectly increasing potential risks of having ER visits. [ABSTRACT FROM AUTHOR]