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The spring system functions as a pivotal element of the check valve, with its compression performance significantly influencing the valve's time, flow stability, and other characteristics. Taking cues from conventional springs, a refined rectangular helical spring with integrated support features was thoroughly evaluated for its compression performance. The design approach for this spring was elucidated, encompassing the utilization of the Finite Element Method (FEM) to model its compression behavior. Additionally, a laboratory configuration was implemented to authenticate the findings derived from the FEM simulation. Subsequently, a comparative investigation was carried out between an engineered spring and a conventional spring subjected to analogous processing. The comparative analysis unveiled that the support-featured spring exhibited a diminished lateral offset of 2.84 mm (equivalent to a reduction of 10.1 %) and a force-displacement curve with narrower vibration intervals and smaller amplitudes. Moreover, it exhibited an enhanced force feedback of 17.5 % under identical compression displacement conditions.

With the introduction of deep learning methods, the computation required for remote sensing change detection has significantly increased, and distributed computing is applied to remote sensing change detection to improve computational efficiency. However, due to the large size of deep learning models, the time-consuming gradient transfer during distributed model training weakens the acceleration effectiveness in change detection. Data communication and updates can be the bottlenecks in distributed change detection systems with limited network resources. To address the interrelated problems, we propose a communication-efficient distributed deep learning remote sensing change detection framework (CEDD-CD) based on the synchronous update architecture. The CEDD-CD integrates change detection with communication-efficient distributed gradient compression approaches, which can efficiently reduce the data volume to be transferred. In addition, for the implicit effect caused by the delay of compressed gradient update, a momentum compensation mechanism under theoretical analysis was constructed to reduce the time consumption required for model convergence and strengthen the stability of distributed training. We also designed a unified distributed change detection system architecture to reduce the complexity of distributed modeling. Experiments were conducted on three datasets; the qualitative and quantitative results demonstrate that the CEDD-CD was effective for massive remote sensing image change detection.

The escalating impacts of human activities on the ecological environment underscore the significance of valuing ecological resources within the paradigm of sustainable development. In this context, the ecological service value (ESV) of the Danjiangkou watershed (Hubei section) was assessed using a revised equivalent factor evaluation method. Additionally, the study determined the human activity intensity (HAI) and employed GeoDetector to delineate the spatial heterogeneity of ESV, thereby investigating the underlying causes. Results show that vegetation coverage attains a high level of 94%, with a minor 1.37% land use change between 2016 and 2020. Secondly, ESV exhibited a substantial variation, rising from 75.55 billion to 79.81 billion yuan, a growth rate of 5.64%. Lastly, the explanatory degree for the synergistic interplay of HAI and expenditure on the spatial variation of ESV surpassed 30%, and the average sensitivity coefficient of up to 0.82 further indicated the apparent impacts of land use and human interference activities on ESV. The study makes an excellent effort to clarify the complex coupling relationships between different land use types and ESV, which could serve as an example and model for other studies in the field.

Accurate diagnostic techniques and effective therapeutic methods are required to treat H. pylori. The application of chicken single-chain variable fragment (scFv) antibodies may diagnose and treat H. pylori. This study used the phage display technique to construct a chicken-derived immune scFv antibody library against H. pylori. Total RNA was extracted from the spleens of five immunized chickens and reverse transcribed into cDNA. A fragment of scFv was produced by overlap extension PCR and cloned into a pHEN2 phagemid vector. After the package with the M13KO7 helper phage, the recombinant HpaA protein was used as a target antigen to validate the screening ability of our antibody library by bio-panning. The dilution counting results showed that the size of the primary antibody library was estimated to be 1 × 109 cfu/mL. PCR analysis of 47 clones from the library revealed that about 100% of the clones were positive with scFv fragments, and there were no identical sequences, indicating the good diversity of the antibody library. After three rounds of bio-panning, high-affinity antibodies against recombinant HpaA protein were successfully obtained. The selected antibody specifically recognized HpaA protein in nine different H. pylori strains, confirming the screening ability of our library. The chicken immune scFv antibody library against H. pylori was successfully constructed, and the antibody library’s screening ability was validated by selecting specific scFv antibodies against recombinant HpaA and clinical strains. It provided a simple and rapid method to obtain antibodies against H. pylori for diagnosis or treatment.

This study investigates the eco-geological environmental challenges faced by Jiangxia District, a mining region in Wuhan City. By combining field surveys, literature analysis and multi-source data such as remote sensing images and on-site monitoring data, an eco-geological environment quality (EGEQ) assessment system was developed. The system consists of six indicators representing biological abundance, vegetation cover, land erosion, water abundance, surface deformation and socio-economic characteristics of the assessed area. The grey relational analysis method was utilized to calculate the weights of each indicator, and the eco-geological environment quality index (EGQI) value was obtained through the linear weighted method. The assessment results indicated a moderate grade of overall eco-geological condition in Jiangxia District between 2017 and 2021, with an 8.56% increase in the EGQI during that period. This suggests a stable and favorable eco-geo logical environment situation in the district during the specified timeframe.

Context Astragalus polysaccharide (APS) is a new tumour therapeutic drug, that has an inhibitory effect on a variety of solid tumours. Tumour cell immunosuppression is related to the up-regulation of programmed death ligand 1 (PD-L1). However, whether APS exerts its antitumor effect by regulating PD-L1 remains unclear.Objective To explore whether APS exerts its antineoplastic effect via regulating PD-L1-mediated immunosuppression in hepatocellular carcinoma (HCC).Materials and methods SMMC-7721 cells were subcutaneous injected into BALB/C mice for HCC model establishment. Mice were intraperitoneally injected with 100, 200 and 400 mg/kg APS for 12 days. Immunohistochemistry (IHC) was performed to assess CD8+ T cells' rate and PD-L1 level in HCC tissues. HCC cells were pre-treated with 0.1, 0.5 and 1 mg/mL APS for 4 h, then were treated with 10 ng/mL IFN-γ 24 h. PD-L1 level and cell apoptosis was detected by flow cytometry. PD-L1 and Moesin (MSN) proteins were measured by western blot. MiR-133a-3p and MSN mRNA levels were assessed by qRT-PCR. The targets of miR-133a-3p were predicted by starBase, and which was verified by dual-luciferase reporter assay.Results Our findings illustrated that APS dose-dependently inhibited HCC growth tested with IC50 values of 4.2 mg/mL, and IFN-γ-induced PD-L1 expression and attenuated PD-L1-mediated immunosuppression in HCC cells. APS attenuated PD-L1-mediated immunosuppression via miR-133a-3p in HCC cells. Besides, miR-133a-3p targeted to MSN, and MSN inhibited the antitumor effect of APS by maintaining the stability of PD-L1. Moreover, APS attenuated PD-L1-mediated immunosuppression via the miR-133a-3p/MSN axis.Conclusions APS attenuated PD-L1-mediated immunosuppression via miR-133a-3p/MSN axis to develop an antitumor effect. APS may be an effective drug for HCC treatment.

Selective attention is an efficient processing strategy to allocate computational resources for pivotal optical information. Here, the authors propose a bionic vision hardware to emulate the behavior, showing a potential in image classification.

IntroductionSpontaneous low-frequency oscillations play a key role in brain activity. However, the underlying mechanism and origin of low-frequency oscillations remain under debate.MethodsOptical imaging and an electrophysiological recording system were combined to investigate spontaneous oscillations in the hemodynamic parameters and neuronal activity of awake and anesthetized mice after Nω-nitro-L-arginine methyl ester (L-NAME) administration.ResultsThe spectrum of local field potential (LFP) signals was significantly changed by L-NAME, which was further corroborated by the increase in energy and spatial synchronization. The important finding was that L-NAME triggered regular oscillations in both LFP signals and hemodynamic signals. Notably, the frequency peak of hemodynamic signals can be different from that of LFP oscillations in awake mice.DiscussionA model of the neurovascular system was proposed to interpret this mismatch of peak frequencies, supporting the view that spontaneous low-frequency oscillations arise from multiple sources.

Considering the excellent properties of polytetrafluoroethylene (PTFE), the demand for this material in semiconductor manufacturing equipment has been rapidly growing in recent years. PTFE parts with special shapes can be efficiently produced by mechanical cutting methods. The main objective of the present study is to conduct turning experiments to evaluate the cutting performance and surface quality of pure PTFE. In this regard, the mechanism of the chips’ formation, cutting temperature, and cutting force were analyzed to study the cutting behavior and cutting performance. Moreover, the subsurface damage of the finished surface was investigated to evaluate the surface quality. The obtained results show that the continuous type of chips was formed in all cutting conditions. When the cutting temperature varied in the range of 40.8–57.9 °C, the cutting force varied in the range of 2.3–25.2 N. The deepest subsurface damage layer was 123.17 μm when the cutting depth and the feed rate were set to 1.0 mm and 0.1 mm/r, respectively. Considering the chip formation, cutting temperature, cutting force, surface quality, and machining efficiency as the main affecting parameters, it is found that the ideal feed rate and cutting depth at the spindle speed of 800 r/min were 0.5 mm/r and 0.8 mm, respectively.

BackgroundChina's manufacturing industry is still labor-intensive, and assembly employees in manufacturing industry are facing a great risk of work-related musculoskeletal disorders (WMSDs). ObjectiveTo investigate and analyze the prevalence and distribution of WMSDs among assembly workers in manufacturing enterprises and explore the relationship between WMSDs and ergonomic exposure factors such as posture load and mental load. MethodsFrom July to September 2017, by convenient sampling, a cross-sectional survey was conducted to select 670 workers engaged in electronic accessories assembly and railway vehicle manufacturing in three manufacturing enterprises in two cities in northern China as the research participants. The posture load assessment was based on the Chinese Musculoskeletal Questionnaire independently developed by our research group. The mental load assessment was based on a revised Chinese version of the Subjective Workload Assessment Technique. An unconditional logistic regression model was used to explore the relationship between ergonomic exposure and WMSDs. ResultsThe overall prevalence rate of WMSDs was 39.6% (265/670) with 43.8% in males and 25.2% in females; the highest prevalence rate was 47.7% in the group aged 40 years and over. The prevalence rate of WMSDs in the electronic accessories assembly workers was 16.9%, that in the railway vehicle manufacturing workers was 57.3%, and the difference was statistically significant (\begin{document}$ {\chi ^2} $\end{document}=112.63, P

BackgroundWork-related musculoskeletal diseases (WMSDs) occur in a variety of occupational populations. Because of their various discomfort and serious disease burden, they have become an important issue worthy of attention in the field of occupational health. The prevention and control of WMSDs is one of the public health problems to be solved.ObjectiveTo evaluate the intervention effect on WMSDs among assembly workers in a railway vehicle manufacturing enterprise, so as to provide scientific basis for the prevention and control of WMSDs.MethodsA total of 250 assembly workers in a railway vehicle manufacturing enterprise were selected using convenience sampling from August to December 2017. The Chinese Musculoskeletal Questionnaire was used for epidemiological investigation, and the Ergonomic Checkpoints was used for ergonomic inspection and worker interview. According to the above survey results, a six-month intervention plan including stepladder improvement and ergonomics training were implemented in the assembly workshop from September 2018 to February 2019. The intervention effects including the awareness of WMSDs, the exposure level of ergonomic load, and the occurrence of WMSDs symptoms were evaluated with relevant cross-sectional survey results before and after the intervention. The scores of WMSDs symptom intensity, symptom duration, and symptom frequency from low to high were 0-10, 1-4, and 1-5, respectively.ResultsAfter the intervention, the awareness rates of assembly workers on WMSDs types, affected body sites, influencing factors, preventive measures, and symptoms all increased from 52.3%, 51.9%, 25.5%, 19.1%, and 51.5% to 68.5%, 61.3%, 48.1%, 40.9%, and 61.3%, respectively (P

Ergonomic exposure is one of the important causes of work-related musculoskeletal disorders (WMSDs). Accurate measurement and evaluation of ergonomic exposure level and implementation of ergonomic intervention are of great significance to the prevention and control of WMSDs. Ergonomic exposure can be divided into external exposure and internal exposure, and its evaluation methods include subjective judgment method, systematic observation method, and direct measurement method. This paper summarized the internal exposure assessment methods based on musculoskeletal dynamics and biomarkers, introduced the overall design concept of ergonomic exposure assessment system, used the Ergonomic Assessment Worksheet (EAWS) as an example, and discussed the development trend of automation, intelligence, and compounding of ergonomic exposure assessment methods and the factors considered in the selection of ergonomic exposure assessment methods.

The health impacts and economic burdens associated by work-related musculoskeletal disorders (WMSDs) have become an important issue in the field of occupational health. Compared with developed countries, we should more systematically carry out in-depth research and practice on occupational ergonomics, comprehensively understand ergonomic factors and their characteristics, and strengthen the intervention and health risk assessment of ergonomic risk factors in key workplaces based on specific production conditions of different industries, so as to prevent and control the occurrence and development of WMSDs. This article introduced the concept, signs, symptoms, risk factors, and currently identifiable site-specific WMSDs. This column presented new research progress from the aspects of ergonomic load assessment methods, the prevalence and related risk factors of WMSDs in different trades, and ergonomic intervention of WMSDs, aiming to provide reference and basis for future research.

BackgroundThe prevalence rate of work-related musculoskeletal disorders (WMSDs) among manufacturing workers is relatively high and has been widely concerned. However, research on the prevalence and risk factors of multi-site WMSDs is still insufficient. ObjectiveTo explore the prevalence and risk factors of multi-site WMSDs of assembly workers in four manufacturing enterprises. MethodsThe "Chinese Musculoskeletal Questionnaire" was used to conduct a cross-sectional survey among 1401 assembly workers selected by convenient sampling in four manufacturing enterprises, and their demographic characteristics, the prevalence of WMSDs in various body parts, and the information about biomechanical factors, work organizations, work environment, and psychosocial factor exposure were collected. The prevalence of WMSDs and multi-site WMSDs were estimated, Pearson χ2 test was used for univariate analysis of multi-site WMSDs risk factors, and logistic regression was used for multi-factor analysis. ResultsThe total prevalence rate of WMSDs was 54.9% (769/1 401). The top three affected sites were neck (41.4%), shoulders (30.7%), and wrist/hand (25.1%). The prevalence rate of multi-site WMSDs was 41.9% (587/1 401). The prevalence rates of multi-site WMSDs in railway vehicle assembly and riveting workers were higher than those in electronic parts processing and glass manufacturing workers (P

The modulation of Schottky barrier, which dominates the carrier injection in vertical organic field-effect transistors, strongly depends on the source electrode. Here, Chen et al. utilize MXene as a source electrode, achieving a subthreshold swing down to 73 mv/dec and a large gate control ability.

The current increase in resistance to antifungal drugs indicates that there is an urgent need to explore novel antifungal drugs with different mechanisms of action. Phosundoxin is a biphenyl aliphatic amide using a TPP-targeting strategy which targets mitochondria. To provide insights into the antifungal activities of phosundoxin, the antifungal susceptibility testing of phosundoxin was conducted on 158 pathogenic fungi and compared to that of traditional azole drugs. Phosundoxin displayed a broad-spectrum antifungal activity on all the tested yeast-like and filamentous fungi ranging from 2 to 16 mg/L. In particular, azole-resistant clinical isolates of Candida albicans were susceptible to phosundoxin with the same MICs as azole-susceptible C. albicans. Transcriptome analysis on azole-resistant C. albicans identified 554 DEGs after treatment with phosundoxin. By integrating GO and KEGG pathway enrichment analysis, the antifungal activity of phosundoxin was related to impairment of mitochondrial respiratory chain function. Acute oral and percutaneous toxicity of phosundoxin to rats showed that the compound phosundoxin were mild toxicity and LD50 was above 5000 mg/kg body weight in rats. This study demonstrated the potential of phosundoxin as an antifungal agent for the treatment of common fungal infection and contributed to providing insights into the mechanisms of action of phosundoxin against C. albicans.

Mycoplasma pneumoniae is a significant cause of community-acquired pneumonia, which is often empirically treated with macrolides (MLs), but, presently, resistance to MLs has been a matter of close clinical concern. This assay is intended to contribute to resistance detection of M. pneumoniae in clinical practice. A novel real-time PCR assay with two non-overlapping probes on the same nucleic acid strand was designed in this study. It could effectively detect all mutation types of M. pneumoniae in 23S rRNA at loci 2063 and 2064. The results were determined by the following methods: ΔCT < 0.5 for MLs-sensitive M. pneumoniae; ΔCT > 2.0 for MLs-resistant M. pneumoniae; 10 copies as a limit of detection for all types. For detection of M. pneumoniae in 92 clinical specimens, the consistency between the results of this assay and the frequently used real-time PCR results was 95.65%. The consistency of MLs resistance results between PCR sequencing and this assay was 100% in all 43 specimens. The assay could not only cover a comprehensive range of targets and have high detection sensitivity but is also directly used for detection and MLs analysis of M. pneumoniae in specimens.

ABSTRACT: Objectives: We analysed the molecular features and antimicrobial susceptibility of Mycoplasma pneumoniae isolates from Weihai, China, in 2019. Methods: Pharyngeal swabs of 160 paediatric patients with pneumonia-related symptoms were collected and were subjected to culture and subsequent characteristic analysis. The characteristics of M. pneumoniae isolates were analysed by real-time PCR and genotyping. Antimicrobial susceptibility testing was performed against four antibiotics. All isolates were amplified for analysis of macrolide (ML) resistance mutations in domain V of the 23S rRNA gene and were genotyped using multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA) and ‘AGT’ VNTR detection in the p1 gene. Results: The M. pneumoniae nucleic acid and culture-positive rate of 160 specimens were 88.1% (141/160) and 51.3% (82/160), respectively. Almost all isolates were ML-resistant (81/82). Point mutation at position 2063 in 23S rRNA was identified in all ML-resistant isolates. The ML resistance rate of M. pneumoniae genotype 2 isolates was 97.6% (41/42). MLVA types 4/5/7/2 and 4/5/7/3 belonged to genotype 1, while type 3/5/6/2 belonged to genotype 2. The numbers of ‘AGT’ VNTR in the p1 gene from all isolates was in the range of 5–15. Conclusion: This is the first report that the two genotypes of M. pneumoniae were present in a relatively equivalent ratio, with genotype 2 slightly predominant, in paediatric patients in Weihai in 2019, and the overall ML resistance rate was close to 100%. The minimum inhibitory concentration (MIC) of erythromycin in M. pneumoniae with ML resistance mutation A2063T in Weihai was higher than previously reported.

BackgroundMusculoskeletal disorders (MSDs) are critical occupational and social problems. With the improvement of production mechanization and automation, and the widespread application of computers, more occupations are exposed to static postures and load. This study explored the role of inflammation in the association between static postures exposure and MSDs.MethodsThis study adopted a prospective nested case-control design in which 66 lower back MSDs cases and 66 healthy controls were selected from a cohort study of university employees. The personal information, postural load, musculoskeletal symptoms, pressure pain thresholds (PPTs), and inflammatory cytokines were collected. Logistic and linear regressions were used to investigate the association among postural load, inflammatory cytokines, and lower back MSDs. Mediation analysis was used to calculate the mediation effect.ResultsThe results of logistic and linear regressions showed that postural load and inflammatory cytokines were positively associated with lower back MSDs (P < 0.05), and postural load was positively associated with inflammatory cytokines (P < 0.05). Further, mediation analysis showed that the mediation effect of postural load on the lower back MSDs through TNF-α was 0.073 (95%CI: 0.025–0.128), and the mediation effect of posture load on the lower back MSDs through IL-6 was 0.098 (95%CI: 0.041–0.179), respectively.ConclusionStatic postures were associated with the occurrence of MSDs through inflammatory cytokines, and low-level inflammation may be a critical early event in the generation of MSDs. This study may help bridge the gap of potential mechanisms linking static postures to increased risks of MSDs, and provide new evidence for targeted protection against the global increasing MSDs.

Campylobacter is among the four main causes of gastroenteritis worldwide. Most reported Campylobacter infections are caused by C. jejuni and C. coli. However, other emerging Campylobacter pathogens have been recognized as important pathogens in humans and animals. A novel bacterial strain, PS10T, was isolated from the gastric mucous of pigs in 2022 in Beijing, China. The cell was Gram-negative, microaerobic, motile, and negative for catalase, oxidase, and urease. Phylogenetic and phylogenomic analyses based on the 16S rRNA gene and core genome indicated that this isolate belongs to the genus Campylobacter. There were low dDDH relatedness and ANI values shared within this strain and its closest species C. mucosalis below the cut-off values generally recognized for isolates of the same species. The draft genome size of PS10T is 2,240,910 bp in length with a percentage of DNA G+C contents of 37.72%. Comparing the phenotypic and phylogenetic features among this isolate and its related organisms, strain PS10T represents a novel species within the genus Campylobacter, for which the name Campylobacter gastrosuis sp. nov. (Type strain PS10T = GDMCC 1.3686T = JCM 35849T) is proposed.

The vast majority of people with cystic fibrosis (CF) are now eligible for CF transmembrane regulator (CFTR) modulator therapy. The remaining individuals with CF harbor premature termination codons (PTCs) or rare CFTR variants with limited treatment options. Although the clinical modulator response can be reliably predicted using primary airway epithelial cells, primary cells carrying rare CFTR variants are scarce. To overcome this obstacle, cell lines can be created by overexpression of mouse Bmi-1 and human TERT (hTERT). Using this approach, we developed 2 non-CF and 6 CF airway epithelial cell lines, 3 of which were homozygous for the W1282X PTC variant. The Bmi-1/hTERT cell lines recapitulated primary cell morphology and ion transport function. The 2 F508del-CFTR cell lines responded robustly to CFTR modulators, which was mirrored in the parent primary cells and in the cell donors’ clinical response. Cereblon E3 ligase modulators targeting eukaryotic release factor 3a (eRF3a) rescued W1282X-CFTR function to approximately 20% of WT levels and, when paired with G418, rescued G542X-CFTR function to approximately 50% of WT levels. Intriguingly, eRF3a degraders also diminished epithelial sodium channel (ENaC) function. These studies demonstrate that Bmi-1/hTERT cell lines faithfully mirrored primary cell responses to CFTR modulators and illustrate a therapeutic approach to rescue CFTR nonsense mutations.

At present, high-precision GNSS positioning technology is an important means to monitor the health of bridges and other structures. However, the GNSS signal of reference stations and monitoring stations used for bridge monitoring can easily be blocked by bridge towers, vehicles, or other objects, resulting in low positioning accuracy and insufficient availability of GNSS, which affects the effectiveness of bridge structural health monitoring. Therefore, according to the characteristics of bridge structure, this paper proposes to take the bridge tower monitoring station as a moving-base station to build the baselines with other monitoring stations and use the moving-base RTK-GNSS method to realize the relative positioning, so as to improve the availability of GNSS in the application of bridge structure health monitoring. In this paper, the moving-base RTK-GNSS model is derived and verified via GNSS monitoring data of the Ganzhou dedicated high-speed railway bridge. The results show that the ambiguity in the fixing rate can be improved using the moving-base RTK-GNSS method with the tower monitoring station as the reference station. The deformation and vibration characteristics of each monitoring point can be reflected, and the displacement and vibration amplitude estimation accuracy can achieve results better than 4 mm. Therefore, the moving-base RTK-GNSS method can be used as an alternative scheme when the observation environment of the base station is poor or the banded engineering monitoring is applied, so as to improve the monitoring capability of GNSS.

This study was aimed at screening potential probiotic candidates to enhance the antimicrobial activity of Artemisia argyi against foodborne pathogens. Ten LAB strains were isolated from natural Artemisia argyi fermentation liquor (AAFL) and assessed for safety and antimicrobial ability. Therein, Lactiplantibacillus plantarum WLPL01, Lacticaseibacillus casei WLCA01, WLCA02, and WLCA03, and Lactobacillus harbiness WLHA01 were further evaluated for their potential probiotic properties (gastrointestinal tolerance and adhesion capacity). The results suggested that L. plantarum WLPL01 exhibited excellent properties and was, therefore, selected as the starter for A. argyi leaves fermentation. Then, L. plantarum WLPL01-fermented AAFL (AAFL-LP) was further investigated for its antimicrobial activity against foodborne pathogens. The results demonstrated that the inhibitory effect of AAFL-LP to foodborne pathogens, such as Listeria monocytogenes CMCC54007, Salmonella Typhimurium ATCC 13311, and Candida albicans ATCC 14053, was enhanced when compared to spontaneously fermented AAFL (AAFL-spontaneous). In addition, an analysis of the whole genome of L. plantarum WLPL01 revealed the presence of 13.9 kb long and 16 plantaricin-encoding loci (pln locus), and the increased antimicrobial activities of AAFL-LP might correlate with the production of bacteriocin. Our results indicate that L. plantarum WLPL01 can be used as a starter for Artemisia argyi fermentation to enhance its antimicrobial activity against foodborne pathogens.

BackgroundHelicobacter pylori (H. pylori) encodes numerous outer membrane proteins (OMPs), with considerable geographic heterogeneity and related to different clinical outcomes. This study aimed to investigate the distribution characteristics of five important OMP genes (sabA, hofC, homA, homB and frpB-4) in different regions of China.Materials and methodA total of 266 strains were isolated from 348 stomach biopsy specimens in Shandong, Guangxi, Heilongjiang, Hunan, and Qinghai provinces. The presence of sabA, hofC, homA, homB and frpB-4 gene was detected by polymerase chain reaction (PCR) from H. pylori genomic DNA.ResultsAmong the strains in five regions, the prevalence of frpB-4 was 100% and that of hofC was 97.7%. The prevalence of homB in the isolates from Qinghai (45.5%) was significantly lower than that in Shandong (75.3%), Guangxi (76.9%) and Hunan (69.6%) (PConclusionThe prevalence of homA, homB, and sabA genes and the sabA "on" or "off" status have significant geographical differences among five provinces in China. The presence of homA and sabA genes may be protective factors of gastritis.

Deep rock will be influenced by the excavation disturbances of different degrees, which seriously affects the safety production of underground mines. Considering that deep rock will be impacted by different temperatures and varied disturbance degrees, this work analyzes the effect of temperature on the dynamic properties of marble by means of the dynamic and static combined SHPB test device. The results reveal that as the temperature climbed, the diameter and height of the specimen increased and the mass and longitudinal wave velocity dropped. The variation laws of total stress–strain curves after varied high temperatures are substantially the same; the peak stress was negatively correlated with the action temperature. At 25 °C~400 °C, the failure mode of specimens is less affected by temperature. When the temperature is higher than 400 °C, the failure degree of specimens increases with the growth of temperature. At 25~400 °C, the above energy varies minimally. At 400~800 °C, with the increase in temperature, the incident energy, transmitted energy and absorption energy decrease, and the reflection energy increases gradually.

A predictive model was proposed for determining the high-temperature free height of perfluoroalkoxy alkane springs in air-operated double-bellow pumps with the aim of investigating their relaxation. The model incorporates classical spring deformation theory and considers the material, structure, and real-world operating conditions of the perfluoroalkoxy alkane springs. Experimental validation of the model is also conducted. This study examines the effects of varying temperatures and pre-compression values on the relaxation of perfluoroalkoxy alkane springs’ free height. It collects relaxation curves under different temperatures and various pre-compression conditions. The results indicate that spring relaxation increases with higher temperatures when there is no precompression. Furthermore, increasing pre-compression at the same temperatures leads to greater spring relaxation. Pre-compression has a more significant impact on spring relaxation. By comparing the experimental data with the simulated curve generated by the model, it is evident that the predicted spring free height relaxation closely aligns with the actual measurements. This verification demonstrates the effectiveness and accuracy of the proposed model in evaluating the relaxation of perfluoroalkoxy alkane springs’ free height. Moreover, the model provides a valuable tool for predicting the lifespan of similar perfluoroalkoxy alkane springs in engineering applications. [ABSTRACT FROM AUTHOR]