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Background Tennis, the second-largest ball game in the world, has a particularly wide audience. To date, little research has been conducted on the biomechanics of female serves. Purpose The purpose of this study was to capture the key moments by using 1,000 frames/s high-speed video analysis, to analyze the kinematics of the serving techniques of national athletes and provincial athletes, to determine the differences between the two levels of athletes, and to provide theoretical references for the improvement of scientific training level. Methods Ten female athletes were selected as participants for this study, five of whom are national athletes, and the other are provincial athletes. Three-dimensional filming techniques were employed to capture videos of the first and second serve techniques. Simi Motion was applied to obtain the 3D kinematic data. Statistical analyses were performed using IBM SPSS Statistics 27.0, and Mann–Whitney U tests were conducted to determine differences between groups. Results Significant differences in kinematics were found between national and provincial athletes. At the moment of the left knee’s minimum flexion (T2), in the first serve, national athletes had a smaller shoulder-hip vertical plane angle (−18.281 ± 6.142° vs. −25.631 ± 3.497°; p = 0.047) and a larger hip vertical plane rotation angle (−9.378 ± 4.263° vs. −0.470 ± 4.724°; p = 0.047). In the second serve, national athletes had a smaller hip horizontal plane rotation angle (−1.720 ± 4.683° vs. 24.146 ± 24.014°; p = 0.047) but a larger hip vertical plane rotation angle (−11.553 ± 1.949° vs. −0.422 ± 4.958°; p = 0.009). At the moment of impact (T4), in the second serve, national athletes’ batting position (0.296 ± 0.088 m vs. 0.446 ± 0.094 m; p = 0.047) was further back. Additionally, in the second serve, national athletes consistently had their body center of gravity further back at T2 (−0.106 ± 0.052 m vs. −0.018 ± 0.048 m; p = 0.028), T3 (0.002 ± 0.038 m vs. 0.132 ± 0.039 m; p = 0.009), and T4 (0.073 ± 0.050 m vs. 0.217 ± 0.034 m; p = 0.009). Conclusions The results of this study indicated several significant kinematic differences between national and provincial athletes, these variations were noted in the shoulder, hip, and body center of gravity. In summary, for the overall first and second serves, it is recommended that national athletes increase the horizontal plane angle of the shoulders and hips at T2, whereas provincial athletes decrease the horizontal plane angle of the shoulder–hip. In addition, provincial athletes need to increase the vertical plane angle of the hip joint, so that the top of the hip can be increased more, and provincial athletes need to be careful not to have the center of gravity too far in front of the body at T2, T3, and T4, so that it can hit the ball at a higher position to increase the swing speed.

Summary: Halophiles, thriving in harsh saline environments, capture scientific interest due to their remarkable ability to prosper under extreme salinity. This study unveils the distinct salt-induced activation of methionine sulfoxide reductases (MsrA) from Halobacterium hubeiense, showcasing a significant enhancement in enzymatic activity across various salt concentrations ranging from 0.5 to 3.5 M. This contrasts sharply with the activity profiles of non-halophilic counterparts. Through comprehensive molecular dynamics simulations, we demonstrate that salt ions stabilize and compact the enzyme’s structure, notably enhancing its substrate affinity. Mutagenesis analysis further confirms the essential role of salt bridges formed by the basic Arg168 residue in salt-induced activation. Mutating Arg168 to an acidic or neutral residue disrupts salt-induced activation, substantially reducing the enzyme activity under salt conditions. Our research provides evidence of salt-activated MsrA activity in halophiles, elucidating the molecular basis of halophilic enzyme activity in response to salts.

BackgroundVaccination can be viewed as comprising the most important defensive barriers to protect susceptible groups from infection. However, vaccine hesitancy for COVID-19 is widespread worldwide. ObjectiveWe aimed to systematically review studies eliciting the COVID-19 vaccine preference using discrete choice experiments. MethodsA literature search was conducted in PubMed, Embase, Web of Science, Scopus, and CINAHL Plus platforms in April 2023. Search terms included discrete choice experiments, COVID-19, and vaccines and related synonyms. Descriptive statistics were used to summarize the study characteristics. Subgroup analyses were performed by factors such as high-income countries and low- and middle-income countries and study period (before, during, and after the pandemic wave). Quality appraisal was performed using the 5-item Purpose, Respondents, Explanation, Findings, and Significance checklist. ResultsThe search yield a total of 623 records, and 47 studies with 53 data points were finally included. Attributes were grouped into 4 categories: outcome, process, cost, and others. The vaccine effectiveness (21/53, 40%) and safety (7/53, 13%) were the most frequently reported and important attributes. Subgroup analyses showed that vaccine effectiveness was the most important attribute, although the preference varied by subgroups. Compared to high-income countries (3/29, 10%), a higher proportion of low- and middle-income countries (4/24, 17%) prioritized safety. As the pandemic progressed, the duration of protection (2/24, 8%) during the pandemic wave and COVID-19 mortality risk (5/25, 20%) after the pandemic wave emerged as 2 of the most important attributes. ConclusionsOur review revealed the critical role of vaccine effectiveness and safety in COVID-19 vaccine preference. However, it should be noticed that preference heterogeneity was observed across subpopulations and may change over time. Trial RegistrationPROSPERO CRD42023422720; https://tinyurl.com/2etf7ny7

Chimeric antigen receptor T (CAR-T) cell therapy targeting T cell tumors still faces many challenges, one of which is its fratricide due to the target gene expressed on CAR-T cells. Despite this, these CAR-T cells can be expanded in vitro by extending the culture time and effectively eliminating malignant T cells. However, the mechanisms underlying CAR-T cell survival in cell subpopulations, the molecules involved, and their regulation are still unknown. We performed single-cell transcriptome profiling to investigate the fratricidal CAR-T products (CD26 CAR-Ts and CD44v6 CAR-Ts) targeting T cells, taking CD19 CAR-Ts targeting B cells from the same donor as a control. Compared with CD19 CAR-Ts, fratricidal CAR-T cells exhibit no unique cell subpopulation, but have more exhausted T cells, fewer cytotoxic T cells, and more T cell receptor (TCR) clonal amplification. Furthermore, we observed that fratricidal CAR-T cell survival was accompanied by target gene expression. Gene expression results suggest that fratricidal CAR-T cells may downregulate their human leukocyte antigen (HLA) molecules to evade T cell recognition. Single-cell regulatory network analysis and suppression experiments revealed that exhaustion mediated by critical regulatory factors may contribute to fratricidal CAR-T cell survival. Together, these data provide valuable and first-time insights into the survival of fratricidal CAR-T cells.

Type 2 diabetes mellitus(T2DM) stands as a significant predisposing factor for cardiovascular diseases,potentially doubling the susceptibility to coronary heart disease and stroke,particularly among the elderly population.Current research on hypoglycemic drugs has evolved beyond mere blood glucose reduction to investigating cardiovascular advantages that extend beyond their hypoglycemic effects.Carotid intima-media thickness(CIMT) serves as a surrogate marker for atherosclerosis,carrying considerable predictive value for future cardiovascular events.This article critically examines the impact of innovative hypoglycemic drugs on CIMT,shedding light on the clinical utility of CIMT in the management of T2DM.

Objective The correct processing and interpretation of geochemical exploration data are critical for regional mineral exploration. High backgrounds may be misjudged as anomalies or low and weak geochemical anomalies may be ignored, if a unified anomaly threshold is adopted for geochemical exploration data in lithologically complex regions due to different elemental abundances in different lithologies. Therefore, it is essential to identify geochemical backgrounds and anomalies in lithologically complex regions based on lithologic classification. Methods Here, we propose a method for delineating geochemical anomalies based on a Gaussian mixture model of factor scores. The geochemical exploration data are subjected to factor analysis after a log-ratio transformation, and then the lithologic classification is completed by the Gaussian mixture model with factor scores. Subsequently, the standardization is performed to eliminate the lithologic background, and geochemical exploration anomalies are delineated with the processed data. This method is used to the geochemical exploration data of 1:200 000 stream sediments in Xupu, Hunan Province. Results The results show that the contents of the metallogenic elements in various lithologies of the study area are partly different, and consequently, it would be unreasonable to adopt a uniform anomaly threshold. In contrast, the method advanced in this paper can accurately classify lithology, eliminate the background of different lithologies, and enhance low and weak anomalies, with the location of the anomalies corresponding to known deposits. Conclusion Hence, the Gaussian mixture model enables effective delineation of geochemical exploration anomalies in lithologically complex regions and provides certain information for further mineral prospecting in this region.

Abstract Somatic cell nuclear transfer (SCNT) can be used to reprogram differentiated somatic cells to a totipotent state but has poor efficiency in supporting full-term development. H3K9me3 is considered to be an epigenetic barrier to zygotic genomic activation in 2-cell SCNT embryos. However, the mechanism underlying the failure of H3K9me3 reprogramming during SCNT embryo development remains elusive. Here, we perform genome-wide profiling of H3K9me3 in cumulus cell-derived SCNT embryos. We find redundant H3K9me3 marks are closely related to defective minor zygotic genome activation. Moreover, SCNT blastocysts show severely indistinct lineage-specific H3K9me3 deposition. We identify MAX and MCRS1 as potential H3K9me3-related transcription factors and are essential for early embryogenesis. Overexpression of Max and Mcrs1 significantly benefits SCNT embryo development. Notably, MCRS1 partially rescues lineage-specific H3K9me3 allocation, and further improves the efficiency of full-term development. Importantly, our data confirm the conservation of deficient H3K9me3 differentiation in Sertoli cell-derived SCNT embryos, which may be regulated by alternative mechanisms.

Lunar dust, the finest fraction of lunar regolith, has undergone important space weathering on the Moon. It not only serves as a record of the evolution of the lunar surface environment and the modification of mineral properties, but also influences the lunar surface environment through dust transport. Our current understanding of the properties and transport mechanisms of lunar dust on the lunar surface, however, remains limited. With rapid development of lunar exploration, it is necessary to further study the problem and meet the need of future lunar exploration missions. The lunar surface is the primary environmental space where uncrewed lunar rover activity, crewed lunar exploration, and lunar base construction take place. The lunar dust will distribute in such a space area due to electrostatic lifting and impacted sputtering, which will pose a threat to lunar surface exploration activities. In addition, lunar dust transport is closely related to lunar horizon glow, lunar swirl, and lunar magnetic anomaly. Understanding the properties and transport mechanisms of lunar dust is key to comprehending the formation of these scientific phenomena. Therefore, a systematic and in-depth investigation of lunar dust properties and dust transport patterns is urgently required to advance lunar science and implement lunar exploration projects. In this study, we summarize the physical and chemical properties of lunar dust and our understanding of dust transport on the lunar surface, identify remaining challenges and issues in the study of lunar dust, and offer perspectives on this research field.

Abstract To fundamentally explore the correlation between crop nutritional quality and mineral elements, specific tests and accurate analysis were carried out on all organs and root soil of watermelon (Citrullus lanatus). The results showed that the distribution patterns of nitrogen and phosphorus at watermelon maturity were similar, and the average nitrogen and phosphorus contents were in the orders of leaf and seed > stem, peel, root > pulp > root soil, and peel > seed > root, stem, leaf > root soil > pulp, respectively. From the perspective of element geochemistry, biophile and lithophile elements had the strongest correlation with nitrogen and phosphorus, and watermelon did not antagonize soil nitrogen and phosphorus uptake. The prediction model of nitrogen translocation factor in watermelon organs to total acid was established by partial least squares with R 2 = 0.81. Significantly, when the isometric log-ratio of nitrogen to phosphorus in watermelon leaves was 1.97 to 2.19, the watermelon pulp showed better quality with total acid > 0.5%, total sugar > 5% and soluble solids > 10%. Therefore, the characterization of nitrogen and phosphorus in watermelon leaves can serve as a non-destructive analysis to predict watermelon fruit quality.

Lead contamination in soil has emerged as a significant environmental concern. Recently, pulse electrochemical treatment (PECT) has garnered substantial attention as an effective method for mitigating lead ions in low-permeability soils. However, the impact of varying pulse time gradients, ranging from seconds to hours, under the same pulse duty cycle on lead removal efficiency (LRE) and energy consumption in PECT has not been thoroughly investigated. In this study, a novel, modified PECT method is proposed, which couples PECT with a permeable reaction barrier (PRB) and adds acetic acid to the catholyte. A comprehensive analysis of LRE and energy consumption is conducted by transforming pulse time. The results show that the LREs achieved in these experiments were as follows: PCb-3 s (89.5%), PCb-1 m (91%), PCb-30 m (92.9%), and PCb-6 h (91.9%). Importantly, these experiments resulted in significant reductions in energy consumption, with decreases of 68.5%, 64.9%, 51.8%, and 47.4% compared to constant voltage treatments, respectively. It was observed that LRE improved with an increase in both pulse duration and voltage gradient, albeit with a corresponding rise in energy consumption. The results also revealed that corn straw biochar as a PRB could enhance LRE by 6.1% while adsorbing migrating lead ions. Taken together, the present data highlights the potential of modified PECT technology for remediation of lead-contaminated soil, which provides an optimal approach to achieve high LRE while minimizing energy consumption.

To improve the main shortcomings of insufficient nutrients, high salinity and low productivity in saline-alkali soils, this study collected saline-alkali soil samples from Da'an City of Baicheng and sediment samples from the adjacent Qianguo irrigation district, measured their pH values and major element contents, designed and verified the improvement scheme of saline-alkali soil based on geochemical engineering principles. Results indicated that the pH value and various element contents of saline-alkali soil could be adjusted by adding sediment to make it close to reference soil. Both theoretical calculation and experimental determination (soil pH, mineral composition, functional group composition and crop growth) revealed that the optimal mixing ratio of saline-alkali soil and sediment was 2:1. The saline-alkali soil amelioration with sediment of adjacent irrigation areas was effectively, low-cost and environment-friendly. The geochemical engineering principle was applicable to the amelioration of saline-alkali soil, but the mixing ratio of saline-alkali soil and sediment in different areas should vary with the local conditions. Meanwhile, theoretical calculation could basically replace the experimental determination to simplify the actual engineering application process. This saline-alkaline soil amelioration method makes full use of the surrounding natural waste and has the advantage of adapting measures to local conditions.

This study was conducted to investigate the effect of Lactobacillus zeae LB2 on the gut microbiota in piglets infected with enterotoxigenic Escherichia coli (ETEC). Thirty-two healthy 7-day-old piglets were randomly divided into four treatment groups: control group (basal diet), LB2 group (supplemented with 1 × 108 CFU/pig/day L. zeae LB2), ETEC group (infected with 1 × 1010 CFU/pig/day ETEC) and ETEC+LB2 group (LB2 supplementation + ETEC infection). Intestinal contents were collected for DNA extraction and Illumina sequencing. Significant result was observed for alpha diversity in the four intestinal sections, and both ETEC infection and LB2 supplementation showed a higher Chao1 alpha diversity. At the phylum level, Firmicutes and Bacteroidetes were dominant in the healthy piglets, while Proteobacteria were dominant in the ETEC-infected piglets. At the genus level, ETEC infection decreased the abundance of Prevotella, Ruminococcaceae, Lactobacillus, Alloprevotella, Flavobacterium, and Sutterella and increased the abundance of Actinobacillus. The LB2 supplementation reduced the abundance of Ruminococcaceae, Actinobacillus, Porphyromonas, and Alloprevotella, and increased the abundance of Prevotella and Lactobacillus. Both ETEC infection and LB2 supplementation affected several functional pathways associated with cellular processes, environmental information processing, genetic information processing, diseases, metabolism, and organismal systems. In summary, ETEC infection induced dysbiosis of the gut microbiome in piglets, while L. zeae supplementation could positively regulate the gut microbiome during ETEC infection. Therefore, L. zeae LB2 may be an ideal probiotic for the prevention or treatment of ETEC infection.

Tourism eco-efficiency analysis is an effective tool to solve the problem of sustainable tourism development. The tourism eco-efficiency evaluation index system was constructed in the study, and the undesirable output super-slacks-based measure model was used to estimate the tourism eco-efficiency of 26 cities in the Yangtze River Delta. Then, the modified gravity model based on the values of the tourism eco-efficiency analysis of each city was used to construct a spatial correlation network. The structural characteristics of the spatial association networks of tourism eco-efficiency, the interrelationships among different cities, and the roles played by different blocks were explored using a social network analysis. The quadratic assignment procedure (QAP) was applied to analyze the influencing factors that affect the formation of the spatial association network of tourism eco-efficiency. The results show that tourism eco-efficiency has an overall increasing trend, and the gap among cities is decreasing. The structure of the spatial correlation network of tourism eco-efficiency has good connectivity, accessibility, and robustness with the correlations among all of the cities in the network. The spillover effects among the blocks are significant, showing spatial polarization, with the cities such as Shanghai, Suzhou, and Hangzhou occupying the core position of the network. The QAP analysis shows that the spatial correlation network of tourism eco-efficiency is affected by the distance between the cities and the levels of development of the economy and information dissemination. The results of this study innovatively reveal the structural characteristics and influencing factors of the spatial correlation network of tourism eco-efficiency. It could provide valuable insights for the development of corresponding policy measures by government sectors and tourism firms to enhance the sustainability of regional tourism development.

To explore the existing characteristics of nitrogen and phosphorus in the main rivers of Changchun City, the overlying water and sediment were sampled and tested. The results showed that the spatial distribution of nitrogen and phosphorus contents in overlying water and sediment was diverse. In overlying water, nitrogen and phosphorus contents in the north and west of Changchun were high, while their contents in the south were low. In the sediment, their contents were high in the south and west and low in the north. The pollution of nitrogen and phosphorus was serious in most rivers. Xinkai River, Chuan Lake, and West Lake had the acutest pollution of ammonia, total nitrogen, and total phosphorus, and their contamination degree in Yongchun River was the lowest. In terms of time, with the government actively carrying out river management, the pollution control of ammonia and phosphorus has achieved remarkable results. The pollution of nitrogen and phosphorus was closely related to the quality of the water environment, and the phosphorus content in overlying water and sediment had the strongest correlation with other water quality parameters. Moreover, the change in chemical oxygen demand could be predicted by the partial least squares method on the basis of its high correlation with nitrogen and phosphorus in overlying water. This study provides a scientific reference for the investigation and treatment of nitrogen and phosphorus pollution in surface water of typical old industrial cities in China.

This study collected 1135 topsoil samples of cultivated land in Laiyang County, eastern China, to analyze the distribution, pollution and health risks of heavy metals (As, Cd, Cu, Cr, Hg, Ni, Pb and Zn). The results show that: (1) the levels of eight heavy metals at some sites were higher than the risk screening values in China, and there was heavy metal pollution. (2) An improved geoaccumulation index was used to evaluate soil pollution. The average value of Igeo before and after improvement was 0.32 (Iml, no pollution to medium pollution) and −0.04 (Iol, no pollution), respectively. (3) Hg and Cd were identified as the main contributors to ecological risk in this study, with a cumulative ecological risk contribution percentage > 65%. The results of the potential ecological risk index (PERI) show that 9.3% of the sampling sites were considered to have moderate ecological risk. (4) As, Pb, Ni and Cu made a contribution of >95% in terms of non-carcinogenic risk to adults and children through different exposure routes, and different soil intake routes posed no non-carcinogenic risk to adults; there was a sampling site with HQChildren > 1, which was consistent with the non-carcinogenic risk site, indicating that children in this location and surrounding areas are more likely to face dual health risks. Therefore, it is necessary to promote the risk management of heavy metals in the study area in order to safely use soil resources.

Tourism is distinctly regional with respect to the regional distribution of tourism resources, tourist attractions and supply, and spatial continuity of tourist activities. Using point-of-interest data from 2166 tourist attractions in the Yangtze River Delta, this study analyzes the spatial distribution pattern of tourist attractions and their influencing factors by applying the methods of nearest proximity index, kernel density analysis, standard deviation ellipse, hotspot analysis, and spatial superposition analysis. The results show that the number of modern recreational tourist attractions accounts for the largest proportion. The spatial distribution pattern shows more attractions in the north than the south and more in the east than the west. The spatial density of tourist attractions in Shanghai is far greater than that in other regions, followed by Jiangsu and Zhejiang. The five types of tourist attractions show a significant aggregation state. Natural ecological tourist attractions are clustered near Nanjing and Huangshan; historical and cultural tourist attractions are formed in a T-shape by Shanghai, Hangzhou, and Nanjing; modern recreational tourist attractions are clustered in Shanghai and Hangzhou; and industrial integration tourist attractions are clustered in Shanghai, Nanjing, and Hangzhou. Physical geography, traffic, and social economy are the main factors affecting the spatial distribution of tourist attractions.