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The present study focuses on investigating the low cycle fatigue (LCF) behavior and cyclic deformation mechanism of Ti–6Al–4V-0.55Fe alloy under strain and stress control. Based on the results of this alloy under strain amplitudes and the corresponding stress amplitudes, the effect of tension-compression asymmetry (TCA) on fatigue behavior and microstructure evolution was systematically discussed with transmission electron microscopy (TEM) and electron backscatter diffraction (EBSD). The results show that under strain control, TCA has little effect on LCF behavior due to the negligible compressive mean stress. And the deformation mechanism is mainly determined by planar slip. While under stress control, the accumulation of significant unidirectional ratcheting strain caused by TCA is observed, resulting in extra heterogeneous plastic deformation and more fatigue damage, responsible for the reduction in fatigue life. However, under low stress amplitude (≤690 MPa), no ratcheting behavior occurs due to the constant strain amplitude (0.56%), which reduces the driving force of crack nucleation and prolongs fatigue life, compared with that under low strain amplitude (0.6%).

Abstract Background Fatty acid binding protein 1 (FABP1), a low molecular weight intracellular protein, has been proposed as a potential useful serum biomarker for liver injury. However, limited investigations have been conducted in chronic hepatitis B virus (HBV)-related liver disease. Objective To investigate the diagnostic potential of FABP1 in disease progression among patients with chronic HBV-related liver disease. Methods A prospective study was conducted on 293 patients with chronic HBV-related liver diseases, including chronic asymptomatic carrier (ASC), chronic hepatitis B (CHB). FABP1 was measured in serum samples collected at admission and some selected liver biopsies. Results Immunohistochemical analysis revealed abundant cytoplasmic expression of FABP1 in hepatocytes. A significant negative correlation was observed between FABP1 expression and inflammation grades in liver tissue (Spearman's r = -0.355, P = 0.017). However, no statistically significant correlation was found with fibrosis (P > 0.05). Serum FABP1 levels in the case group were significantly higher than in the healthy control (HC) group [median: 804.2 (687.8, 939.2) vs. 709.1 (626.2, 807.8) ng/ml, Z = -5.505, P

The infectious disease surveillance system is a key support tool for public health decision making. Current research concentrates on optimizing static sentinel deployment to address the problem of incomplete data due to the lack of sufficient surveillance resources. In this study, we introduce an information-guided adaptive learning strategy for the dynamic surveillance of infectious diseases. The goal is to improve monitoring effectiveness in situations where it is possible to adjust the focus of surveillance, such as serial surveys and allocation of testing tools. Specifically, we develop a probabilistic neural network model to learn spatio-temporal correlations among the numbers of infections. Based on a probabilistic model, we evaluate the information gain of monitoring a spatio-temporal target and design a greedy selection algorithm for monitoring targets selection. Moreover, we integrate two major surveillance objectives, i.e., informativeness and coverage, in the monitoring target selection. The experimental results on the synthetic dataset and two real-world datasets demonstrate the effectiveness of our approach, showcasing the promise of further exploration and application of dynamic adaptive active surveillance.

Abstract Salicylic acid (SA) plays an essential role in plant defense against biotrophic and semi‐biotrophic pathogens. Following pathogen recognition, SA biosynthesis dramatically increases at the infection site of the host plant. The manner in which pathogens sense and tolerate the onslaught of SA stress to survive in the plant following infection remains to be understood. The objective of this work was to determine how the model phytopathogen Xanthomonas campestris pv. campestris (Xcc) senses and effluxes SA during infection inside host plants. First, RNA‐Seq analysis identified an SA‐responsive operon Xcc4167–Xcc4171, encoding a MarR family transcription factor HepR and an RND (resistance‐nodulation‐cell division) family efflux pump HepABCD in Xcc. Electrophoretic mobility shift assays and DNase I footprint analysis revealed that HepR negatively regulated hepABCD expression by specifically binding to an AT‐rich region of the promoter of the hepRABCD operon, Phep. Second, isothermal titration calorimetry and further genetic analysis suggest that HepR is a novel SA sensor. SA binding released HepR from its cognate promoter Phep and then induced the expression of hepABCD. Third, the RND family efflux pump HepABCD was responsible for SA efflux. The hepRABCD cluster was also involved in the regulation of culture pH and quorum sensing signal diffusible signaling factor turnover. Finally, the hepRABCD cluster was transcribed during the XC1 infection of Chinese radish and was required for the full virulence of Xcc in Chinese radish and cabbage. These findings suggest that the ability of Xcc to co‐opt the plant defense signal SA to activate the multidrug efflux pump may have evolved to ensure Xcc survival and virulence in susceptible host plants.

Atmospheric corrosion of Al–Cu–Li AA2195 alloys was investigated in constant relative humidity (RH) controlled by saturated salt solutions. Corrosion process was governed by RH, especially for the transformation of corrosion products and crack growth. The deceleration corrosion kinetics and maximum pit depth were found to be in accordance with the power laws. The corrosion products gradually transformed from γ-Al(OH)3 and γ-AlOOH into NaAlCO3(OH)2 and γ-Al(OH)3 affected by RH and exposure time. The localized formation of pitting, filiform and exfoliation corrosion was induced by the presence of Cu/Mg/Li-containing secondary precipitates, including T1(Al2CuLi), θ'(Al2Cu) and S'(Al2CuMg) phases. Secondary precipitates with lower potential were prone to triggering intergranular corrosion. The primary cracks penetrated into the internal matrix along large angular grain boundaires. Secondary cracks propagated along corrosion channels of the stress-concentrated triple grain boundaries with higher schimd factors, larger Kernel average misorientation and higher geometrically necessary dislocation densities. A crack propagation mechanism controlled by RH was proposed.

Abstract Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot in Brassica vegetables, which can induce the host plant to produce salicylic acid and 4-hydroxybenzoic acid (4-HBA) during infection. Xcc was previously shown to sense and degrade host plant-derived 4-HBA via the sensor PobR and a PobA-dependent pathway. The degradation of 4-HBA is associated with Xcc virulence in cabbage. The present study generated a reporter strain XC1::PpobA-gusA to monitor pobA transcription. 4-HBA-like compounds were screened for their ability to interfere with pobA transcription. Benzoic acid (BA) was found to efficiently decrease pobA transcription in a dose-dependent manner. Xcc neither produced nor degraded BA; however, the exogenous addition of BA to the 4-HBA-containing Xcc culture significantly decreased the 4-HBA degradation rate. Furthermore, addition of BA into the Xcc culture did not significantly affect the transcription of pobA or pobR; however, addition of BA into the 4-HBA-containing culture significantly decreased the transcription of both genes. Isothermal titration calorimetry and an electrophoretic mobility shift assay revealed that BA binds to PobR with a moderate affinity, which interfered with the binding of 4-HBA/PobR complex to the pobA promoter and thereby inhibiting pobA transcription and 4-HBA degradation. The endogenous BA level of the infected cabbage leaves increased in response to Xcc infection. In the presence of BA, the virulence of Xcc on cabbage decreased significantly. Taken together, these results suggest that cabbage utilizes BA to interfere with 4-HBA degradation, thereby reducing Xcc virulence. Thus, BA has the potential to be developed as a bactericide against Xcc infection.

Abstract Strong early growth vigor is an essential target in both direct seeded rice breeding and high-yielding rice breeding for rice varieties with relatively short growth duration in the double-cropping region. Shoot dry weight (SDW) is one of the important traits associated with early growth vigor, and breeders have been working to improve this trait. Finding stable QTLs or functional genes for SDW is crucial for improving the early growth vigor by implementing molecular breeding in rice. Here, a genome-wide association analysis revealed that the QTL for SDW, qSDW-5, was stably detected in the three cultivation methods commonly used in production practice. Through gene-based haplotype analysis of the annotated genes within the putative region of qSDW-5, and validated by gene expression and knockout transgenic experiments, LOC_Os05g09520, which is identical to the reported GW5/GSE5 controlling grain width (GW) and thousand grain weight (TGW) was identified as the causal gene for qSDW-5. Five main haplotypes of LOC_Os05g09520 were identified in the diverse international rice collection used in this study and their effects on SDW, GW and TGW were analyzed. Phenotypic comparisons of the major haplotypes of LOC_Os05g09520 in the three subpopulations (indica, japonica and aus) revealed the same patterns of wider GW and higher TGW along with higher SDW. Furtherly, the haplotype analysis of 138 rice varieties/lines widely used in southern China showed that 97.8% of the cultivars/lines carry Hap2 LOC_Os05g09520 . These results not only provide a promising gene source for the molecular breeding of rice varieties with strong early growth vigor, but also elucidate the effect of the LOC_Os05g09520 haplotypes on SDW, GW, and TGW in rice. Importantly, this study provides direct genetic evidence that these three traits are significantly correlated, and suggests a breeding strategy for developing high-yielding and slender grain-shaped indica cultivars with strong early growth vigor.

At present, a single post-processing technology will always introduce secondary defects (trace pollution elements and structural defects) while removing surface processing defects of fused silica components, which limits the further improvement of the laser damage threshold of the components. Therefore, to effectively remove surface defects in optically-processed fused silica and suppress defect regeneration is the key to improve the laser damage resistance performance of the components. Based on the complementarity of anisotropic ion beam etching and isotropic HF acid etching, a combined etching technology is proposed for fused silica components used in engineering. The combined etching can remove most of the fragmented defects on fused silica surface to achieve relatively good surface quality with a root mean square roughness of 0.666 nm. After the combined etching, the contents of most impurity elements decrease by approximately an order of magnitude. Besides, the contents of the structural defects significantly reduce. Therefore, The zero probability damage threshold and the 100 % probability damage threshold increase by 32.41 % and 57.46 %, respectively. The results show that the combined etching technology can effectively improve the laser damage resistance performance of fused silica components, especially under high fluence laser irradiation, which is very important for the high power output and stable operation of laser facilities.

Rice (Oryza sativa L.) is one of the major food crops worldwide. With global warming and the continuous growth of the population, the increase of agricultural water use and the reduction of available freshwater resources, drought stress has become the most serious abiotic stress affecting the growth, development and yield of rice. Breeding drought-resistant varieties is the most effective and economical measure to cope with drought stress, and exploring drought-resistant genes is a foundation of drought-resistance breeding. Researches have showed that, the drought resistance of rice is a complex quantitative trait controlled by many genes, involving a complex network of genes. In this regulatory network, transcription factors play a vital role. Transcription factors refer to proteins that can specifically bind to the cis-acting elements in the promoter region of a gene, and they play an important role in regulating plant growth and development, metabolic processes, and biotic and abiotic stress processes. In rice, a variety of transcription factors involved in the response to drought stress have been identified, including members of the bZIP, MYB, NAC, DREB, WRKY, zinc finger protein, SPL, bHLH, MADS, heat shock protein and GRAS families. When rice is subjected to drought stress, these transcription factors regulate the adaptability of rice to drought stress by specifically regulating the expression of a series of downstream target genes. In this article, we review the function of transcription factors in rice response to drought stress in recent years. By thoroughly analyzing the biological functions and mechanisms of action of transcription factors, it will help to strengthen the understanding about the molecular basis of rice drought resistance and provide an important theoretical basis for breeding new rice varieties with drought resistance.

Abstract Cooking quality is the main factor determining the market value of rice. Although several major genes and a certain number of QTLs controlling cooking quality have been identified, the genetic complexity and environmental susceptibility limit the further improvement for cooking quality by molecular breeding. This research conducted a genome-wide association study to elucidate the QTLs related to cooking quality including amylose content (AC), gel consistency (GC) and alkali spreading value (ASV) by using 450 rice accessions consisting of 300 indica and 150 japonica accessions in two distinct environments. A total of 54 QTLs were identified, including 25 QTLs for AC, 12 QTLs for GC and 17 QTLs for ASV. Among them, 10 QTLs were consistently observed by the same population in both environments. Six QTLs were co-localized with the reported QTLs or cloned genes. The Wx gene for AC and GC, and the ALK gene for ASV were identified in every population across the two environments. The qAC9-2 for AC and the qGC9-2 for GC were defined to the same interval. The OsRING315 gene, encoding an E3 ubiquitin ligase, was considered as the candidate gene for both qAC9-2 and qGC9-2. The higher expression of OsRING315 corresponded to the lower AC and higher GC. Three haplotypes of OsRING315 were identified. The Hap 1 mainly existed in the japonica accessions and had lower AC. The Hap 2 and Hap 3 were predominantly present in the indica accessions, associated with higher AC. Meanwhile, the GC of accessions harboring Hap 1 was higher than that of accessions harboring Hap 3. In addition, the distribution of the three haplotypes in several rice-growing regions was unbalanced. The three traits of cooking quality are controlled by both major and minor genes and susceptible to environmental factors. The expression level of OsRING315 is related to both AC and GC, and this gene can be a promising target in quality improvement by using the gene editing method. Moreover, the haplotypes of OsRING315 differentiate between indica and japonica, and reveal the differences in GC and AC between indica and japonica rice.

The low-cycle fatigue properties of titanium alloys suffering cyclic loading determines the safety in service for their components used in submarine shells. It has been reported that tensile property could be improved by making use of Fe alloying element partitioning effect. However, the fatigue property and mechanism of titanium alloys with Fe addition remain unknown. In this study, the low-cycle fatigue property and cyclic deformation mechanism of Ti–6Al–4V-0.55Fe and Ti–6Al–4V ELI with a duplex microstructure were systematically investigated. With the addition of Fe element, Ti–6Al–4V-0.55Fe with longer lasting cyclic hardening behavior and lower cyclic softening rate, showed higher fatigue life under selected strain amplitudes. Under low strain amplitude, effect of Fe on dislocation motion, interface resistance, lattice distortion, and micro strain were responsible for the enhanced fatigue life. While under high strain amplitude, Fe brought out the pinning effect on interface. Besides, Fe addition also limited the fatigue crack propagation.

The influences of simultaneous precipitation of isothermal ω and O′ on deformation mechanisms and mechanical properties of near β Ti alloy Ti-5Al-3Mo-3V-2Cr-2Zr-1Nb-1Fe with (α + β) hybrid structure are revealed. During continuous heating, the phase transformation sequence in this alloy is β + αp + ω-embryos + O′ → β + αp + ωiso + O′ → β + αp + ωiso + O′ + αs → β + αp + αs. Low-temperature heat treatments from 200 °C to 400 °C are carried out to develop such intermediate phases. Upon aging at 200 °C and 300 °C, the isothermal ω and O′ domains are continuously generated. In comparison with solution state, the deformation behaviors of aged samples are altered, and the yield stress and ductility are simultaneously increased. When aged at 200 °C, the yield strength is increased by 13.8 %, and fracture elongation is increased by 63.2 %. When aged at 300 °C, the yield strength is increased by 18.2 %, and preserves large ductility same to solution state. This is due to the development of isothermal ω and O′ domains suppress long-range stress induced martensitic transformation during loading, and the deformation mechanisms evolve into dislocations slipping gradually. When the aging temperature increases to 400 °C, α precipitation takes place leading to an obvious decrement in ductility. Upon loading the primary α can also accommodate partly the strains and relax local stress concentration. The results in this work clearly proves that better mechanical properties can be achieved through tailoring intermediate phases generation.

Abstract Background The La-related proteins (LARPs) are a superfamily of RNA-binding proteins associated with regulation of gene expression. Evidence points to an important role for post-transcriptional control of gene expression in germinating pollen tubes, which could be aided by RNA-binding proteins. Results In this study, a genome-wide investigation of the LARP proteins in eight plant species was performed. The LARP proteins were classified into three families based on a phylogenetic analysis. The gene structure, conserved motifs, cis-acting elements in the promoter, and gene expression profiles were investigated to provide a comprehensive overview of the evolutionary history and potential functions of ZmLARP genes in maize. Moreover, ZmLARP6c1 was specifically expressed in pollen and ZmLARP6c1 was localized to the nucleus and cytoplasm in maize protoplasts. Overexpression of ZmLARP6c1 enhanced the percentage pollen germination compared with that of wild-type pollen. In addition, transcriptome profiling analysis revealed that differentially expressed genes included PABP homologous genes and genes involved in jasmonic acid and abscisic acid biosynthesis, metabolism, signaling pathways and response in a Zmlarp6c1::Ds mutant and ZmLARP6c1-overexpression line compared with the corresponding wild type. Conclusions The findings provide a basis for further evolutionary and functional analyses, and provide insight into the critical regulatory function of ZmLARP6c1 in maize pollen germination.

Abstract Cultivating rice varieties with robust blast resistance is the most effective and economical way to manage the rice blast disease. However, rice blast disease comprises leaf and panicle blast, which are different in terms of resistance mechanisms. While many blast resistant rice cultivars were bred using genes conferring resistance to only leaf or panicle blast, mining durable and effective quantitative trait loci (QTLs) for both panicle and leaf blast resistance is of paramount importance. In this study, we conducted a pangenome-wide association study (panGWAS) on 9 blast resistance related phenotypes using 414 international diverse rice accessions from an international rice panel. This approach led to the identification of 74 QTLs associated with rice blast resistance. One notable locus, qPBR1, validated in a F4:5 population and fine-mapped in a Heterogeneous Inbred Family (HIF), exhibited broad-spectrum, major and durable blast resistance throughout the growth period. Furthermore, we performed transcriptomic analysis of 3 resistant and 3 sensitive accessions at different time points after infection, revealing 3,311 differentially expressed genes (DEGs) potentially involved in blast resistance. Integration of the above results identified 6 candidate genes within the qPBR1 locus, with no significant negative effect on yield. The results of this study provide valuable germplasm resources, QTLs, blast response genes and candidate functional genes for developing rice varieties with enduring and broad-spectrum blast resistance. The qPBR1, in particular, holds significant potential for breeding new rice varieties with comprehensive and durable resistance throughout their growth period.

With the increasing demand for metal foil parts with micro-array structures in micro-electromechanical systems (MEMS), it is urgent to explore a novel array micro-forming technology with high efficiency, low cost, and high flexibility. The cavitation water jet uses the high-energy shock wave generated by the collapse of the cavitation bubble group as the loading force. It has the characteristics of large range of action, uniform pressure distribution, and can realize large-area array micro-forming processing. To verify the feasibility of cavitating water jet array micro-forming, this paper performs cavitating water jet array micro-forming on 304 stainless steel foil with a thickness of 80 μm, and analyzes the variation of cavitation bubbles collapse impact zone with target distance. The effects of target distance and impact time on the forming quality of metal foil array micro-holes were studied from the aspects of forming depth, surface roughness, and thickness thinning rate. The results show that the forming depth and uniformity of the array micro-holes located in the cavitation collapse area increase with time. However, with the increase of target distance, the forming depth increases first and then decreases. When the target distance is L = 120 mm, the forming depth reaches the maximum. The surface roughness ( Ra ) of the array micro hole is Ra = 1.54 μm. The thickness thinning rate of the micro-forming parts is between 2% and 10%, and the maximum thickness thinning rate in the die fillet area is 13.5%. This paper provides a novel processing method for manufacturing metal foil parts with micro array structure.

Abstract Pseudomonas aeruginosa is a ubiquitous and metabolically versatile microorganism naturally found in soil and water. It is also an opportunistic pathogen in plants, insects, animals, and humans. In response to increasing cell density, P. aeruginosa uses two acyl‐homoserine lactone (AHL) quorum‐sensing (QS) signals (i.e., N‐3‐oxo‐dodecanoyl homoserine lactone [3‐oxo‐C12‐HSL] and N‐butanoyl‐homoserine lactone [C4‐HSL]), which regulate the expression of hundreds of genes. However, how the biosynthesis of these two QS signals is coordinated remains unknown. We studied the regulation of these two QS signals in the rhizosphere strain PA1201. PA1201 sequentially produced 3‐oxo‐C12‐HSL and C4‐HSL at the early and late growth stages, respectively. The highest 3‐oxo‐C12‐HSL‐dependent elastase activity was observed at the early stage, while the highest C4‐HSL‐dependent rhamnolipid production was observed at the late stage. The atypical regulator RsaL played a pivotal role in coordinating 3‐oxo‐C12‐HSL and C4‐HSL biosynthesis and QS‐associated virulence. RsaL repressed lasI transcription by binding the –10 and –35 boxes of the lasI promoter. In contrast, RsaL activated rhlI transcription by binding the region encoding the 5′‐untranslated region of the rhlI mRNA. Further, RsaL repressed its own expression by binding a nucleotide motif located in the –35 box of the rsaL promoter. Thus, RsaL acts as a molecular switch that coordinates the sequential biosynthesis of AHL QS signals and differential virulence in PA1201. Finally, C4‐HSL activation by RsaL was independent of the Las and Pseudomonas quinolone signal (PQS) QS signaling systems. Therefore, we propose a new model of the QS regulatory network in PA1201, in which RsaL represents a superior player acting at the top of the hierarchy.

Abstract Strong seedling vigor is imperative to achieve stable seedling establishment and enhance the competitiveness against weeds in rice direct seeding. Shoot length (SL) is one of the important traits associated with seedling vigor in rice, but few genes for SL have been cloned so far. In the previous study, we identified two tightly linked and stably expressed QTLs for SL, qSL-1f and qSL-1d by genome-wide association study, and cloned the causal gene (LOC_Os01g68500) underlying qSL-1f. In the present study, we identify LOC_Os01g66100 (i.e. the semidwarf gene SD1), a well-known gene controlling plant height (PH) at the adult-plant stage, as the causal gene underlying qSL-1d through gene-based haplotype analysis and knockout transgenic verification. By measuring the phenotypes (SL and PH) of various haplotypes of the two genes and their knockout lines, we found SD1 and LOC_ Os01g68500 controlled both SL and PH, and worked in the same direction, which provided the directly genetic evidence for a positive correlation between SL and PH combined with the analysis of SL and PH in the diverse natural population. Moreover, the knockout transgenic experiments suggested that SD1 had a greater effect on PH compared with LOC_ Os01g68500, but no significant difference in the effect on SL. Further investigation of the pyramiding effects of SD1 and LOC_Os01g68500 based on their haplotype combinations suggested that SD1 may play a dominant role in controlling SL and PH when the two genes coexist. In this study, the effect of SD1 on SL at the seedling stage is validated. In total, two causal genes, SD1 and LOC_ Os01g68500, for SL are cloned in our studies, which controlled both SL and PH, and the suitable haplotypes of SD1 and LOC_ Os01g68500 are beneficial to achieve the desired SL and PH in different rice breeding objectives. These results provide a new clue to develop rice varieties for direct seeding and provide new genetic resources for molecular breeding of rice with suitable PH and strong seedling vigor.

Inhibiting the death receptor 3 (DR3) signaling pathway in group 3 innate lymphoid cells (ILC3s) presents a promising approach for promoting mucosal repair in individuals with ulcerative colitis (UC). Paeoniflorin, a prominent component of Paeonia lactiflora Pall., has demonstrated the ability to restore barrier function in UC mice, but the precise mechanism remains unclear. In this study, we aimed to delve into whether paeoniflorin may promote intestinal mucosal repair in chronic colitis by inhibiting DR3 signaling in ILC3s. C57BL/6 mice were subjected to random allocation into 7 distinct groups, namely the control group, the 2 % dextran sodium sulfate (DSS) group, the paeoniflorin groups (25, 50, and 100 mg/kg), the anti-tumor necrosis factor-like ligand 1A (anti-TL1A) antibody group, and the IgG group. We detected the expression of DR3 signaling pathway proteins and the proportion of ILC3s in the mouse colon using Western blot and flow cytometry, respectively. Meanwhile, DR3-overexpressing MNK-3 cells and 2 % DSS-induced Rag1−/− mice were used for verification. The results showed that paeoniflorin alleviated DSS-induced chronic colitis and repaired the intestinal mucosal barrier. Simultaneously, paeoniflorin inhibited the DR3 signaling pathway in ILC3s and regulated the content of cytokines (Interleukin-17A, Granulocyte-macrophage colony stimulating factor, and Interleukin-22). Alternatively, paeoniflorin directly inhibited the DR3 signaling pathway in ILC3s to repair mucosal damage independently of the adaptive immune system. We additionally confirmed that paeoniflorin-conditioned medium (CM) restored the expression of tight junctions in Caco-2 cells via coculture. In conclusion, paeoniflorin ameliorates chronic colitis by enhancing the intestinal barrier in an ILC3-dependent manner, and its mechanism is associated with the inhibition of the DR3 signaling pathway.

BackgroundEmerging infectious diseases pose a significant threat to global public health. Timely detection and response are crucial in mitigating the spread of such epidemics. Inferring the onset time and epidemiological characteristics is vital for accelerating early interventions, but accurately predicting these parameters in the early stages remains challenging.MethodsWe introduce a Bayesian inference method to fit epidemic models to time series data based on state-space modeling, employing a stochastic Susceptible-Exposed-Infectious-Removed (SEIR) model for transmission dynamics analysis. Our approach uses the particle Markov chain Monte Carlo (PMCMC) method to estimate key epidemiological parameters, including the onset time, the transmission rate, and the recovery rate. The PMCMC algorithm integrates the advantageous aspects of both MCMC and particle filtering methodologies to yield a computationally feasible and effective means of approximating the likelihood function, especially when it is computationally intractable.ResultsTo validate the proposed method, we conduct case studies on COVID-19 outbreaks in Wuhan, Shanghai and Nanjing, China, respectively. Using early-stage case reports, the PMCMC algorithm accurately predicted the onset time, key epidemiological parameters, and the basic reproduction number. These findings are consistent with empirical studies and the literature.ConclusionThis study presents a robust Bayesian inference method for the timely investigation of emerging infectious diseases. By accurately estimating the onset time and essential epidemiological parameters, our approach is versatile and efficient, extending its utility beyond COVID-19.

Southern rice black-streaked dwarf virus disease (SRBSDVD), which is transmitted by the Sogatella furcifera and caused by the infection of southern rice black-streaked dwarf virus (SRBSDV). The disease was first discovered in southern China in 2001 and has since spread, causing increasing damage to rice production in southern China. And it has been one of the main diseases damaging rice production in southern China. Due to the strong migratory ability, large population and persistent transmission of the white-backed planthopper, chemical pesticides have proven to be ineffective in pest and disease control. So far, there is no sustainable and environmentally friendly means to control this disease. Based on the outbreak of the pathogenic virus and the biological characteristics of its vector, the white-backed planthopper, it is expected that the disease will be one of the most serious rice diseases in China for a long period of time in the future, and there is a high likelihood of outbreak of epidemics. Therefore, there is an urgent need to breed resistant rice varieties that can withstand SRBSDVD. In this review, we summarize the pathogenicity of SRBSDVD, collection and evaluation of resistant germplasm resources, the precise positioning of resistance genes/QTLs, and the molecular mechanisms of resistance genes. In addition, the study further explores the use of modern molecular biological techniques, including molecular marker-assisted selection, gene silencing (RNAi) and gene editing, to accelerate the selection and breeding of disease-resistant varieties of SRBSDVD, which will provide a basis for effective control of SRBSDVD in the future.

Abstract Plant disease is a threat to global food security. Breeding crops carrying broad-spectrum resistance loci is an effective way to control infectious disease. Disease-resistant mutants are valuable resources for deciphering the underlying mechanisms of plant immunity and could provide genetic loci to generate disease-resistant crops. Here, we identified a rice mutant, rbr7 (rice blast resistance 7), that confers resistance against different strains of Magnaporthe oryzae. Disease-mimicking necrotic lesions started to appear on the leaves of rbr7 four weeks after sowing. Histochemical analysis revealed reactive oxygen species accumulation and cell death accompanied by spontaneous lesion formation in rbr7. Map-based cloning and bulk segregation analysis showed a 2855 bp fragment deletion on chromosome 5, leading to the disruption of the LOC_Os05g28480-coding protein. Transgenic rbr7 complementation plants showed compromised resistance to rice blast, indicating that LOC_Os05g28480, or Rbr7, regulates the rice immune response. Rbr7 encodes a small protein of unknown function with 85 amino acids. Transcriptomic analysis revealed that disruption of RBR7 led to the upregulation of genes responding to salicylic acid, systemic acquired resistance and pathogenesis-related genes. Taken together, our findings reveal insights into a novel small protein involved in regulating plant resistance to rice blast and provide a potential target for crop breeding.

A comprehensive investigation of friction stirring additive manufacturing (FSAM) Mg–10Li–3Al–3Zn alloy has been conducted to evaluate microstructure evolution and mechanical properties. The results indicated that new intermetallic compounds of Li2MgAl and LiMgZn are precipitated. The microstructure homogeneity is improved and the texture strength of [−1100] is decreased via FSAM. Compared to the base metal, the microhardness of nugget zone has increased by 33%, and the tensile strength of the samples along transverse direction and process direction are 206 MPa and 224 MPa, respectively. The strengthen mechanism of mechanical properties also has been analyzed through phase distribution and grain refinement. The study reveals that FSAM is a significant approach for the additive manufacturing magnesium alloys.

The mid-infrared optical frequency comb is a powerful tool for gas sensing. In this study, we demonstrate a simple mid-infrared dual-comb spectrometer covering 3–4 μm in LiNbO3 waveguides. Based on a low-power fiber laser system, the mid-infrared comb is achieved via intra-pulse difference frequency generation in the LiNbO3 waveguide. We construct pre-chirp management before supercontinuum generation to control spatiotemporal alignment for pump and signal pulses. The supercontinuum is directly coupled into a chirped periodically poled LiNbO3 waveguide for the 3–4 μm idler generation. A mid-infrared dual-comb spectrometer based on this approach provides a 100 MHz resolution over 25 THz coverage. To evaluate the applicability for spectroscopy, we measure the methane spectrum using the dual-comb spectrometer. The measured results are consistent with the HITRAN database, in which the root mean square of the residual is 3.2%. This proposed method is expected to develop integrated and robust mid-infrared dual-comb spectrometers on chip for sensing.

Liver cancer is a huge global challenge. It has been exacerbated by tumor-associated dendritic cells (TDCs) due to Endoplasmic Reticulum (ER) stress. We planned to investigate the effects of LBP3 on TDCs immune function, and to explore whether the underlying mechanism was associated with IRE1α-XBP1 pathway of ER stress regulating lipid metabolism. In our early studies, LBP3 (40–350 kDa) with significant anti-tumor and immunomodulatory activities was isolated from the polysaccharide of Lycium barbarum L. (LBP). Here, we determined that LBP3 had a great anti-tumor efficacy in H22-tumor bearing mice by functional activation of TDCs. In vivo and in vitro results showed that LBP3 could up-regulate the expression of MHC Ⅱ, CD80 and CD86 on TDCs, increase the level of TNF-α secreted by TDCs, enhance TDCs’ ability to improve the proliferation and immunosuppression of lymphocytes. Furthermore, LBP3 could decrease the high expression of ER stress-related proteins IRE1α, GRP78, XBP1 and CHOP, reduce the lipid accumulation, raise the low expression of costimulatory molecules on TDCs induced by thapsigargin (TG). Taken together, LBP3 could reduce intracellular lipid accumulation by inhibiting IRE1α-XBP1 pathway of ER stress, improve the function of TDCs to stimulate T cells, thence play an anti-tumor role.

Abstract Exposure to extreme temperatures or fine particles is associated with adverse health outcomes but their interactive effects remain unclear. We aimed to explore the interactions of extreme temperatures and PM2.5 pollution on mortalities. Based on the daily mortality data collected during 2015–2019 in Jiangsu Province, China, we conducted generalized linear models with distributed lag non-linear model to estimate the regional-level effects of cold/hot extremes and PM2.5 pollution. The relative excess risk due to interaction (RERI) was evaluated to represent the interaction. The relative risks (RRs) and cumulative relative risks (CRRs) of total and cause-specific mortalities associated with hot extremes were significantly stronger (p

This work aims to study the influence of laser power on the microstructural evolution of novel Ti–6Zr–5Fe alloy fabricated by selective laser melting (SLM). The microstructural evolutions of all top surfaces in SLM Ti–6Zr–5Fe alloy samples fabricated from 80 W to 140 W were investigated in depth. The microstructure in SLM Ti–6Zr–5Fe alloy includes α phase and β phase, the size of the β phase and α phase increases with the increase of laser power due to the decrease of cooling rate. Meanwhile, the melt pool overlapping width increases with the increase of melt pool width due to the increase of laser power. The increase of melt pool overlapping causes the re-heating or re-melting of SLM Ti–6Zr–5Fe alloy. Moreover, as the laser power increases from 80 W to 140 W, the change of the melt pool greatly influenced the size, morphology, crystallographic orientation of the β phase, and their distributions. The increase of laser power causes adequate precipitation of the α phase, which improves the microhardness from 466 HV to 533 HV. The laser power can effectively regulate and control the microstructure and microhardness of SLM Ti alloys.

Cadmium (Cd) accumulation in rice grain is of health concern. Identifying genes involved in grain Cd accumulation and performing molecular breeding may reduce it. In this study, knockout of OsNRAMP2, a member of the NRAMP family, reduced grain Cd concentrations by more than 38%, and overexpressing OsNRAMP2 increased grain Cd concentrations by more than 50%. Physiological experiments showed that OsNRAMP2 facilitated Cd translocation from root to shoot by positively regulating Cd efflux from the vacuoles. At filling stage, OsNRAMP2 was highly expressed in all tissues except for husk, suggesting its role in Cd remobilization. Changes in OsNRAMP2 expression affected the concentrations of Fe, Mn, Zn, and Cu in grain and also affected rice growth. Phylogenetic analysis showed that the distribution of OsNRAMP2 haplotypes between japonica and indica was different. Among the four haplotypes of OsNRAMP2, Hap 1, with a 6-bp nucleotide insertion in exon 1, had grain Cd concentration at least 45.3% lower than any of the other three haplotypes. Almost all (99.3%) japonica accessions but rare indica accessions (4.44%) from the 3K sequenced rice genomes carry Hap 1 of OsNRAMP2. Our study sheds light on the molecular mechanism of grain Cd accumulation and provides a promising target for low-Cd rice breeding.

Titanium alloys with high strength and good corrosion resistance have become one of the critical bearing structural materials in marine engineering. But in service, corrosion fatigue would occur under the synergetic action of cyclic external load and corrosion environment, threatening the safety of components. In this study, compared with low-cycle fatigue in laboratory air, the low-cycle corrosion fatigue deformation mechanism and fracture characteristic of the Ti-6Al-4V-0.55Fe alloy were investigated in 3.5% NaCl corrosion solution under selected stress amplitudes. The results showed that under low stress amplitude, corrosion fatigue was determined by fatigue damage and corrosion damage, causing a reduction in fatigue life. The local stress concentration caused by corrosion pits and dislocations pile-up accelerated the initiation of fatigue cracks, and other corrosion behavior including crevice corrosion promoted fatigue crack propagation; the corrosion solution increased the surface damage. While under high stress amplitude, due to the short contact time between the sample and solution and higher applied stress, the fatigue life is determined by fatigue damage caused by multiple slips.

In recent years, environmental problems have been a hot topic of social concern, such as heavy metal pollution in the atmosphere, soil and sediment, which are closely related to our life.To solve the heavy metal pollution in environment, the key is to determine the source of pollution.With the rapid development of stable isotope tracer technology, further achievements have been made in the study of the traceability of heavy metal pollution. Meanwhile, isotope tracer technology has become an important means in the traceability of heavy metal pollution.To better understand the isotope tracer technology application in environmental pollution sourcing, having the copper isotope as an example, the basic properties of copper, isotope fractionation in the geochemical process, processing and purification different types of samples, isotope analyze technique, tracer technique, the meta model has carried on the brief summary.This paper further describes the end members(natural input source and artificial input source), pollution path and pollution degreeof river pollution, smelter pollution and atmospheric particulate pollution. Finally, the application of isotope tracer is summarized and prospected.

Abstract Background A pangenome aims to capture the complete genetic diversity within a species and reduce bias in genetic analysis inherent in using a single reference genome. However, the current linear format of most plant pangenomes limits the presentation of position information for novel sequences. Graph pangenomes have been developed to overcome this limitation. However, bioinformatics analysis tools for graph format genomes are lacking. Results To overcome this problem, we develop a novel strategy for pangenome construction and a downstream pangenome analysis pipeline (PSVCP) that captures genetic variants’ position information while maintaining a linearized layout. Using PSVCP, we construct a high-quality rice pangenome using 12 representative rice genomes and analyze an international rice panel with 413 diverse accessions using the pangenome as the reference. We show that PSVCP successfully identifies causal structural variations for rice grain weight and plant height. Our results provide insights into rice population structure and genomic diversity. We characterize a new locus (qPH8-1) associated with plant height on chromosome 8 undetected by the SNP-based genome-wide association study (GWAS). Conclusions Our results demonstrate that the pangenome constructed by our pipeline combined with a presence and absence variation-based GWAS can provide additional power for genomic and genetic analysis. The pangenome constructed in this study and the associated genome sequence and genetic variants data provide valuable genomic resources for rice genomics research and improvement in future.

Context Chinese herb Huangqin decoction (HQD) can regulate intestinal flora in ulcerative colitis (UC) mice. Objective Our study clarifies the mechanism of HQD in regulating the intestinal flora of UC mice. Materials and methods Male C57BL/6 mice were randomly divided into six groups: Control, Model (3% DSS), Sulfasalazine (500 mg/kg), HQD-L (250 mg/kg), HQD-M (500 mg/kg), and HQD-H (1000 mg/kg) groups. Measurement of body weight, colon length, DAI, and haematoxylin–eosin staining were conducted. FISH and 16S rDNA detected colonic bacterial infiltration and intestinal flora changes. The expression of RegIIIγ and PRRs (NOD2, TLR5, TLR4) were detected by FCM and WB, respectively. In addition, WB, qPCR, or IHC were used to detect the expression of NOD2, MyD88, RIP2, and NF-κB p65 in the colon. ELISA was used to determine cytokines. Results Compared with the model group (DAI score, 2.38 ± 0.05; histological score, 4.08 ± 0.54), HQD treatment significantly reduced the DAI score (L, 2.16 ± 0.09; M, 1.45 ± 0.05; H, 1.18 ± 0.05) and histological score (L, 3.16 ± 0.82; M, 2.50 ± 0.81; H, 1.51 ± 0.76); restored the weight, the colonic length (p

Microstructural evolution and its effect on microhardness and Young's modulus of Ti–6Zr–4Fe alloy solution and aging treated at different temperatures were studied. The α phase transformed into β phase completely at 860 °C, meanwhile, the athermal ω phase was found at 860 °C and it resulted in a higher Young's modulus. The ω phase content increased from 250 °C to 400 °C, and the content decreased with further increase of aging temperature, there were only α phase and β phase at 600 °C. The phase transformation sequence was β → ω + β → ω + α + β → α + β during aging treatment. The microhardness increased from 315 HV to 492 HV due to the element solution strengthening and phase transformation strengthening. The peak microhardness of Ti–6Zr–4Fe alloy aged at 400 °C reached 652 HV. The formation of ω phase resulted in the increase of microhardness and Young's modulus in Ti–6Zr–4Fe alloy.

The prevalence of substantial inflammation or fibrosis in treatment-naïve patients with chronic hepatitis B (CHB) and normal alanine transaminase (ALT) levels is high. A retrospective analysis was conducted on 559 consecutive patients with hepatitis B virus infection, who underwent liver biopsy, to investigate the value of noninvasive models based on routine serum markers for evaluating liver histology in CHB patients with normal or mildly elevated ALT levels and to provide treatment guidance. After comparing 55 models, we identified the top three models that exhibited excellent performance. The APGA model, based on the area under the receiver operating characteristic curve (AUROC), demonstrated a superior ability to evaluate significant (AUROC = 0.750) and advanced fibrosis (AUROC = 0.832) and demonstrated a good performance in assessing liver inflammation (AUROCs = 0.779 and 0.874 for stages G ≥ 2 and G ≥ 3, respectively). APGA also exhibited significant correlations with liver inflammation and fibrosis stage (correlation coefficients, 0.452 and 0.405, respectively (p < 0.001)). When the patients were stratified into groups based on HBeAg status and ALT level, APGA consistently outperformed the other 54 models. The other top two models, GAPI and XIE, also outperformed models based on other chronic hepatitis diseases. APGA may be the most suitable option for detecting liver fibrosis and inflammation in Chinese patients with CHB.

【Objective】This study was committed to explore low-temperature germinability (LTG) related genes of rice, and clarify the molecular mechanism, which can provide theoretical foundation for genetic modification and molecular breeding of low-temperature germinability in rice.【Method】Based on the acquired RNA-seq data of low-temperature germination in different rice accessions, differentially expressed genes (DEGs) were screened out. Genetic transformation materials of the chosen DEG were constructed, which were applied for the identification of gene function through seed germination trials.【Result】A Yippee family member encoding gene OsYIPL1, which had a higher expression level in high LTG accessions, was chosen for further study. The results of temporal and spatial expression of OsYIPL1 showed that it was specifically expressed higher in rice anther and young embryo. Two over-expression lines of OsYIPL1, OX-1and OX-2, were acquired and the seeds from the T2 generation were applied for germination trials at normal temperature (28℃) and low temperature (13 ℃). The results showed that when the expression of OsYIPL1 was increased to 44.5 times that of the wild type (OX-1), the germination rate of its seeds at normal temperature was 18.3% higher than that of the wild type on average. When the expression of OsYIPL1 was increased to 88.9 times that of the wild type (OX-2), the germination rate of its seeds at normal temperature was 54.5% lower than that of the wild type. At low temperature, overexpression of OsYIPL1 could reduce seed germination, and the germination rates of OX-1 and OX-2 were 43.8% and 81.5% lower than those of the control on average.【Conclusion】OsYIPL1 participates in regulation of rice seed germination, but the effects are obviously different at different temperatures. The underlying mechanism is waiting for further research.

Flow softening and microstructural evolution of a novel near β titanium alloy Ti–3Al–5Mo–4Cr–2Zr–1Fe (Ti-35421) with tensile strength beyond 1200 MPa have been investigated at temperatures of 710∼800 °C in the α+β region with strain rates of 0.001∼1 s−1 during hot deformation. The established Arrhenius constitutive model embedded softening mechanism and deformations can predict the flow stress and match the experimental data well. Two mechanisms of dynamic recrystallization (DRX) including the continuous dynamic recrystallization (CDRX) of subgrains rotating and the discontinuous dynamic recrystallization (DDRX) of grain boundaries bulging govern the hot deformation and microstructural evolution. Both CDRX and DDRX occur at high true strains and the number of DRX grains increases with increasing true strain. An obvious flow softening phenomenon presents during thermal compression at the low temperature and low strain rates in the α+β region, which might be attributed to the bending and fragmentation of α phases, inverse change of the texture intensity between α and β phases, and the formation of the new grains from DRX.

Grain chalkiness is the main factor determining the market value of rice. Reducing chalkiness is an important breeding goal for genetic improvement of high quality rice. Identification of QTLs or genes controlling chalkiness is the prerequisite for molecular breeding in rice. Here, we conducted a genome-wide association study to identify QTLs associated with grain chalkiness including percentage of grains with chalkiness (PGWC) and degree of endosperm chalkiness (DEC) in 450 rice accessions consisting of 300 indica and 150 japonica rice in two environments. A total of 34 QTLs were identified, including 14 QTLs for PGWC and 20 QTLs for DEC. Among them, seven QTLs were commonly identified in two environments, and eight QTLs were simultaneously related to two traits. Based on the haplotype analysis, LD decay analysis, RNA-sequencing, qRT-PCR confirmation and haplotype comparisons, four genes (LOC_Os10g36170, LOC_Os10g36260, LOC_Os10g36340 and LOC_Os10g36610) were considered as the candidate genes for qDEC-10c1w,2wj, which could be identified in both environments and had the most significant p-value among the newly identified QTLs. These results provided new insight into the genetic basis of grain chalkiness and gene resources for improving quality by molecular breeding in rice.

Abstract Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot of cruciferous plants, which harbor high levels of hydroxycinnamic acids (HCAs) in their above-ground parts. Thus, upon infection of the host plant, the pathogen experiences a complex cocktail of HCAs. The present study shows that Xcc can efficiently degrade the HCAs, 4-hydroxycinnamic acid (4-HCA), ferulic acid (FA) and sinapic acid (SiA), via an hca cluster which encodes putative genes for a 4-hydroxycinnamoyl-CoA synthetase/4-HCA ligase HcaL, a benzaldehyde dehydrogenase HcaD, a 4-hydroxycinnamoyl-CoA hydratase/lyase HcaH and a member of the MarR-family of transcriptional factors, HcaR. Xcc also degrades the HCA caffeic acid, but with an alternative mechanism. RT-PCR and subsequent GUS assays show that the hca cluster is transcribed within a single operon, and its transcription is specifically induced by 4-HCA, FA and SiA. Furthermore, we show that HcaR negatively regulates hca transcription when its ligand, the proposed degradation pathway intermediate HCA-CoA, is not present. HcaR specifically binds to a 25-bp site, which encompasses the -10 elements of the hca promoter. Finally, GUS histochemical staining and subsequent quantitative analysis shows that the hca cluster is transcribed in planta during pathogenesis of Chinese radish, and hca deletion mutant strains exhibit compromised virulence in cabbage. Together, these results suggest that the ability to degrade HCAs contributes to Xcc virulence by facilitating its growth and spread, and by protecting the pathogen from HCA toxicity. A working model to explain Xcc HCA sensing and subsequent induction of the HCA degradation process is proposed.

Abstract Objectives This study aims to further investigate the association of COVID-19 disease severity with numerous patient characteristics, and to develop a convenient severity prediction scale for use in self-assessment at home or in preliminary screening in community healthcare settings. Setting and participants Data from 45,450 patients infected with COVID-19 from January 1 to February 27, 2020 were extracted from the municipal Notifiable Disease Report System in Wuhan, China. Primary and secondary outcome measures We categorized COVID-19 disease severity, based on The Chinese Diagnosis and Treatment Protocol for COVID-19, as “nonsevere” (which grouped asymptomatic, mild, and ordinary disease) versus “severe” (grouping severe and critical illness). Results Twelve scale items—age, gender, illness duration, dyspnea, shortness of breath (clinical evidence of altered breathing), hypertension, pulmonary disease, diabetes, cardio/cerebrovascular disease, number of comorbidities, neutrophil percentage, and lymphocyte percentage—were identified and showed good predictive ability (area under the curve = 0·72). After excluding the community healthcare laboratory parameters, the remaining model (the final self-assessment scale) showed similar area under the curve (= 0·71). Conclusions Our COVID-19 severity self-assessment scale can be used by patients in the community to predict their risk of developing severe illness and the need for further medical assistance. The tool is also practical for use in preliminary screening in community healthcare settings. Summary Our study constructed a COVID-19 severity self-assessment scale that can be used by patients in the community to predict their risk of developing severe illness and the need for further medical assistance.

A coherent beam combination has the potential to revolutionize high-peak-power laser systems. However, achieving a high-average-power ultrashort pulse is difficult due to the accumulation of a nonlinear phase and gain narrowing. In this article, we demonstrate a coherent beam combination system that does not require pulse shaping or a spectral modulator. By optimizing the gain of each amplifier and using highly integrated optical components, we reduce the limitations caused by the accumulation of a nonlinear phase and gain narrowing. In our study, we used a polarization beam splitter to combine the pulses from two rod-type photonic crystal fibers (PCFs) in a Mach–Zehnder-type interferometer. A piezo-mounted mirror controlled with a Hänsch–Couillaud polarization detecting system was used to stabilize active phase locking. The system produces 165 W with a 91.6% combining efficiency compared to 90 W per amplifier. Compressed pulses with an energy of 132 µJ and Gaussian fitting pulse duration of 330 fs were achieved.

Traditional rural homegarden agroforestry system in the Chengdu Plain of China, called “Linpan” in Chinese, integrates the ecological functions of the landscape with human production activities. Studying the driving mechanisms of rural landscape changes in the Chengdu Plain is of great significance from stakeholders’ perspective. Taking the Pidu Linpan Farming System (PLFS) in the suburban area of Chengdu (designated as one of China-Nationally Important Agricultural Heritage Systems in 2020) as a case, this study combined remote sensing image analysis, oral history interviews, and focus group interviews to elucidate the driving forces of landscape changes in the PLFS. The results show that tourism development, traffic accessibility, economic demand, and agricultural heritage protection measure are the main driving forces promoting the stability and maintenance of the traditional homegardens. In contrast, population ageing, land circulation, centralized residence, climate change, and living and recreational need are the forces leading to adverse changes in the traditional homegardens. In addition, these driving forces have led to the gradual abandonment of traditional agricultural activities and critical issues related to rural landscape planning and management. The current research indicates that infrastructure construction and increased traditional agricultural income are considered as the best practices of local stakeholders, promoting the development of the protected homegardens of heritage sites and tourist destinations. Finally, we put forward some suggestions to improve and maintain the traditional rural landscape: (1) establishing a benefit-sharing mechanism; (2) establishing a training system with traditional technology and culture; (3) strengthening infrastructure construction; (4) promoting the development of the agricultural industry; (5) improving the cultural quality of farmers; and (6) establishing a management system with legal effects. This research can provide a basis for the formulation of rural landscape planning and the orderly and healthy development of agricultural heritage in Chengdu Plain.

Bioactive porous structure coatings have received extensive attention because they can significantly improve the surface bioactivity of medical metal implants. However, traditional porous making technologies were restricted by the “upward growth” mode, with an obvious interface with the substrate, resulting in weak bonding and biological safety problems. This research innovatively proposed to selectively dissolve harmful Al element on the surface of Ti6Al4V alloy through an electrochemical dealloying process, forming a three-dimensional grid porous structure in situ on the surface, with the following three notable advantages: (1) The dealloying process was a “downward growth” mode, there was no obvious interface between the porous layer and the substrate, so the bond was firm; (2) The harmful element Al was effectively removed, and the biological safety was greatly improved; (3) The three-dimensional grid porous structure owned high-efficiency osteogenic activity, which solved the problem of Ti6Al4V biological inertness. The electrode potential and corrosion current density difference of metal elements were studied by electrochemical methods to analyze the corrosion and dissolution mechanism, the successful removal of the element Al, and the thickness of the porous layer were analyzed by XPS sputtering. Furthermore, the bioactivity was verified by co-cultivation with osteoblasts. Interestingly, the results of ALP expression, collagen secretion, and calcification all implied that the dealloyed porous structure could significantly promote the osteogenic differentiation of cells. Employing the electrochemical dealloying, a “subtractive” structure was formed on the surface of Ti6Al4V, which greatly improves the bioactivity and at the same time increased its osteogenic activity, which displayed extremely high research value and bright application value.

Bulk Ti-6Al-4V alloys have been fabricated by selective laser melting (SLM) in three recipes with different combinations of powder sizes. Combinatorial effects of initial gas-atomized powder sizes on microstructure and corrosion properties of SLM-ed Ti-6Al-4V alloys have been investigated by optical microscopy, X-ray diffraction, electrochemical measurements and surface free energy. The SLM-ed Ti-6Al-4V alloys are composed of acicular α' martensite and α phases. Many pinhole defects and twin boundaries exist in the SLM-ed Ti-6Al-4V alloys. According to electrochemical tests and surface free energy calculation, the SLM-ed Ti-6Al-4V alloys with 0 – 53 μm powders have the most positive corrosion potential, the lowest current density and the smallest surface free energy of 20.89 mJ m2. The passive film of SLM-ed Ti-6Al-4V alloys with 0 – 53 μm powders has superior protection ability due to their large thickness. The carrier concentration of SLM-ed Ti-6Al-4V alloys with 0 – 53 μm powders is the lowest by the Mott-Schottky curves. The SLM-ed samples with contact angles higher than 90º are hydrophobic, but the small contact angle of 46.98º reflects the hydrophilic features of as-rolled Ti-6Al-4V alloys. The combinatorial recipe of SLM-ed Ti-6Al-4V alloys with 0 – 53 μm powders is optimal for improvements on the corrosion resistance.

Titanium alloys have great potential as candidate materials for the deep-sea facilities. Long-term creep deformation behavior of the pressure-bearing structures made of titanium alloys under alternating compressive stress has a direct impact on the structural stability. The compressive creep evaluations of Ti-6Al-4V ELI alloys with basketweave microstructure under alternating stresses have been carried out by a uniaxial compressive creep tester. The compressive creep deformations have strong stress sensitivity due to the larger creep strain by the higher applied compressive stress. The dislocation densities in α and β phases increase with the increase of applied compressive stresses. The dislocation slip and dislocation multiplication occur in α phases accompanying with high dislocations density in β phases caused by compressive deformation. The large strain concentration occurs at the grain boundaries of α/β phase due to dislocation plug after creep, which causes the grain boundary pinning. The compressive creep deformation of Ti-6Al-4V ELI alloys under alternating stress is a decelerating creep process and controlled by dislocation slip. The slight refinements of the grains and hardening have been confirmed after creeps. The synergistic effects of dislocation multiplication, grain boundary pinning and grain refinements lead to strengthening the Ti-6Al-4V ELI alloys and decelerating the compressive creeps.

High-salinity and blast disease are two major stresses that cause dramatic yield loss in rice production. GF14 (14-3-3) genes have been reported to play important role in biotic and abiotic stresses in plants. However, the roles of OsGF14C remain unknown. To understand the functions and regulatory mechanisms of OsGF14C in regulating salinity tolerance and blast resistance in rice, we have conducted OsGF14C-overexpressing transgenic experiments in the present study. Our results showed that overexpression of OsGF14C enhanced salinity tolerance but reduced blast resistance in rice. The enhanced salinity tolerance is related to the reduction of methylglyoxal and Na+ uptake instead of exclusion or compartmentation and the negative role of OsGF14C in blast resistance is associated with the suppression of OsGF14E, OsGF14F and PR genes. Our results together with the results from the previous studies suggest that the lipoxygenase gene LOX2 which is regulated by OsGF14C may play roles in coordinating salinity tolerance and blast resistance in rice. The current study for the first time revealed the possible roles of OsGF14C in regulating salinity tolerance and blast resistance in rice, and laid down a foundation for further functional study and crosstalk regulation between salinity and blast resistance in rice.

With the concept of "healthy lifestyle" deeply rooted in people's minds, the sports service industry is thriving, which has resulted in intense competition. The sports service industry must improve its service quality to be competitive. Customer orientation is the key factor for enterprises to gain competitive advantage. With the in-depth understanding of internal marketing in the service industry. Managers have realized that treating employees as internal consumer is a good way to improve their satisfaction and gain customer orientation. However, what internal marketing strategies will have a positive effect on internal consumer satisfaction and customer orientation of private-owned sports center employees are still unclear. In this investigation, a total of 326 employees from the private-owned sports center were used to investigate the effects of internal marketing strategies on internal consumer satisfaction and customer orientation. All employees were asked to complete a questionnaire on 5-point scale. A path model was used to investigate the direct and indirect effects of hypothetical measurements on internal consumer satisfaction and customer orientation. The findings suggested that internal communication, administrative support, and educational training were important factors affecting internal consumer satisfaction and customer orientation. We concluded that the implementation of internal marketing strategies could improve internal consumer satisfaction and customer orientation, and higher levels of internal consumer satisfaction will encourage employees to have higher degrees of customer orientation. Therefore, the implementation of internal marketing strategy was beneficial to the development of private-owned sports centers.

We report a compact, tunable, self-starting, all-fiber laser-based asynchronous optical sampling (ASOPS) system. Two Er-doped fiber oscillators were used as the pulsed-laser source, whose repetition rate could be set at 100 MHz with a tuning range of 1.25 MHz through a fiber delay line. By employing phase-locked and temperature control loops, the repetition rate offset of the two lasers was stabilized with 7.13 × 10−11 fractional instability at an average time of 1 s. Its capabilities in the terahertz regime were demonstrated by terahertz time-domain spectroscopy, achieving a spectral bandwidth of 3 THz with a dynamic range of 30 dB. The large range of repetition rate adjustment in our ASOPS system has the potential to be a powerful tool in the terahertz regime.

Histone-like nucleoid-structuring (H-NS) proteins are key regulators in gene expression silencing and in nucleoid compaction. The H-NS family member proteins MvaU in Pseudomonas aeruginosa are thought to bind the same AT-rich regions of chromosomes and function to coordinate the control of a common set of genes. Here, we explored the molecular mechanism by which MvaU controls PCA biosynthesis in P. aeruginosa PA1201. We present evidence suggesting that MvaU is self-regulated. Deletion of mvaU significantly increased PCA production, and PCA production sharply decreased when mvaU was over-expressed. MvaU transcriptionally repressed phz2 cluster expression and consequently reduced PCA biosynthesis. β-galactosidase assays confirmed that base pairing near the −35 box is required when MvaU regulates PCA production in PA1201. Electrophoretic mobility shift assays (EMSA) and additional point mutation analysis demonstrated that MvaU directly bound to an AT-rich motif within the promoter of the phz2 cluster. Chromatin immunoprecipitation (ChIP) analysis also indicated that MvaU directly bound to the P5 region of the phz2 cluster promoter. MvaU repression of PCA biosynthesis was independent of QscR and OxyR in PA1201 and neither PCA or H2O2 were the environmental signals that induced mvaU expression. These findings detail a new MvaU-dependent regulatory pathway of PCA biosynthesis in PA1201 and provide a foundation to increase PCA fermentation titer by genetic engineering.

In this study, the effect of Fe addition on microstructure evolution and grain refinement mechanism during hot deformation of new Ti-6Al-4V-xFe (x = 0–0.9 wt%) alloys were investigated. The peak stress showed a decreasing trend, and the microstructure presented obvious grain refinement with the increase of Fe content. The flow softening behavior was contributed by dynamic recovery (DRV) and dynamic recrystallization (DRX). The average grain size decreased from 52.2 μm to 11.3 μm, and the fraction of the high angle grain boundary (HAGB) increased from 66.49% to 76.33% when Fe concentration increased from 0 wt% to 0.9 wt%. Fe addition also facilitated in the annihilation of the dislocations, which resulted in a decrease in the average ρGND density. The high Schmid factor (>0.45) content increased with the Fe content in the basal slip (0001) and prismatic slip {101¯1} of the α phase, as well as in the {112¯} and {123¯} slip systems of the β phase. All evidence indicated that Fe addition promoted the hot workability of the Ti-6Al-4V-xFe (x = 0–0.9 wt%) alloys and refined the grain size during hot deformation.

In the present work, low cycle fatigue (LCF) behavior and fracture characteristic of Ti–6Al–4V-0.55Fe alloy with bimodal microstructure, consisted of equiaxed primary α (αp), lamellar α (αl) and β matrix, are systematically investigated at room temperature. Results indicate that Ti–6Al–4V-0.55Fe alloy mainly exhibits a continuous softening behavior both at high and low strain amplitudes, due to the interaction of back stress(σb) and friction stress(σf) mainly related to the plastic deformation heterogeneity and precipitates shearing, respectively. Compared with Ti–6Al–4V alloy, LCF life of Ti–6Al–4V-0.55Fe is similar at high strain amplitudes (Δεt/2 > 1.0%), while much higher at low strain amplitudes (Δεt/2

The interaction of 980-nm continuous laser radiation with the plasma of a continuous optical discharge in xenon lamps at a pressure of p = 12 atm has been studied. The threshold power and characteristics of the laser required to sustain the xenon plasma became our focus. According to the theory of Gaussian beam propagation, the laser parameters after collimation and focusing are obtained by combining ZEMAX simulation and the actual measurement. The influence of the beam waist ω0, which determines the power density distribution at focus, and the Rayleigh range Z0, which determines the energy concentration range, on the threshold maintenance power is expounded. The results show that there is a threshold power density for the generation of plasma, whose value is about 1,500–2,000 W/mm2, and that the threshold maintenance power of the plasma shows an overall decreasing trend with decreasing ω0. When ω0 is reduced to a higher power density that can easily maintain the thermodynamic equilibrium process of the plasma, the mismatch between Z0 and the plasma size caused by the decrease in Z0 makes the threshold power tend to be stable and increasing.