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Abstract This article describes a quantitative assessment method proposed to quickly identify the degree of deterioration of hardened leather artefacts. We used three techniques to artificially age samples, namely, dry-heat ageing (DH), UV-ageing (UV), and alkali-thermal ageing (AT). The deterioration mechanisms were studied via thermogravimetry/derivative thermogravimetry (TG/DTG) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Combined with amide III band deconvolution and second derivative fitting, we constructed a method for assessing the degree of deterioration by the relative content of random coils (referred to as R) in the secondary structure of the protein. The results show that with increasing ageing time, the macrostructures and microstructures of the leather changed to varying degrees. This study elucidates the differential behaviour of vegetable-tanned leather collagen under oxidative and hydrolytic mechanisms. Based on the deterioration characteristics and fitting results, we divided the hardened leather into the following three levels. Mild deterioration: 0 ≤ R ≤ 5%; leather with reduced pores and slight dryness and hardness but with a stable collagen structure; if the β-sheet content is ≥ 68% at this point, the leather may be recrosslinked by ultraviolet irradiation. Moderate deterioration: 6 ≤ R ≤ 25%; partial hydrogen bond breaking in leather, loosening of the collagen–tan matrix, dry and hard curling of the leather surface, and fibre cementation. Severe deterioration: R ≥ 40%, β-sheet ≤ 24%, and the α-helix is higher; surface reflection, severe macroscopic deformation and embrittlement, and the breakdown and gelatinization of the three-stranded helical structure of leather proteins. The quantitative analysis method was suitable for studying the deterioration mechanisms and assessing the degree of deterioration in Heishanling leather artefacts, which also provides a new practical scheme for assessing the degree of hardened leather. Graphical Abstract

Abstract Objective This study aimed to investigate the associations between physical activity (PA) intensity, occupational PA engagement, and sarcopenia in younger adults. Methods Data from the National Health and Nutrition Examination Survey (NHANES) (from 2011 to 2018) were used for the study. PA data were extracted for the Global Physical Activity Questionnaire, and the ratio of limb muscle mass (ALM) to body mass index (BMI) was used to determine sarcopenia. Multiple logistic regression was performed, and dose-response curves were drawn to evaluate the associations. Results Of the 8802 adults aged 20 to 59 years, 770 (8.7%) were identified as having sarcopenia. Compared to those in the reference group, the participants in the “low”, “moderate”, and “high” total METs groups had lower risks of sarcopenia (low: OR = 0.730, 95% CI = 0.583; 0.915; moderate: OR = 0.643, 95% CI = 0.485; 0.853; high: OR = 0.560, 95% CI = 0.457; 0.687). The risk of sarcopenia decreased in the high-intensity recreational PA group; however, such a significant association was observed only in the high-intensity occupational PA group. The relationship between total METs and sarcopenia showed a nonlinear U-shaped trend. Conclusions A greater intensity of PA is associated with a lower risk of sarcopenia among younger adults, regardless of whether moderate or vigorous PA is performed. Moreover, recreational PA may particularly advantageously contrast with occupational PA in lowering the risk of sarcopenia.

Abstract With the progress of micro electromechanical system (MEMS) technology, the performance of MEMS inertial measurement unit (IMU) composed of gyroscopes and accelerometers has been improved. Among the inertial sensors, MEMS triaxial gyroscope plays an important role in attitude estimation, navigation and positioning of intelligent mobile terminals such as unmanned aerial vehicles and unmanned vehicles. However, the measured values of low and medium cost MEMS triaxial gyroscopes are mainly affected by temperature (or thermal effect) and random errors. As results, the drift errors correlated with temperature will reduce application accuracy of MEMS triaxial gyroscope. The traditional calibration method for thermal drift errors relies on the expensive equipment, such as turntable and the temperature control system, which increases the cost of calibration. Therefore, an effective thermal calibration method that is available when using low- or high-cost tools for MEMS triaxial gyroscope will be meaningful for majority users. Hence, this paper analyzed and established the thermal drift model of MEMS triaxial gyroscope, and proposed a segmented systematic calibration method based on 24 states according to this model. Simulation shows that the proposed method can obtain the results approaching the real parameter thermal drift curves. Calibration experiments and parameters test show that the max errors of attitude calculation are reduced to 10% of the results using the original parameters, which indicates that the effectiveness of the proposed method.

【Objective】The use of artificial inoculation to ferment cigar tobacco leaves is an inevitable trend in the industrial production of cigar tobacco leaves, and the neutral aroma components are the important quality components of cigar tobacco leaves. The study aims to investigate the effect of Bacillus safensis GL2 on the neutral aroma components of cigar tobacco leaves.【Method】GL2 was screened from Cuban cigar Cohiba Robert and used to ferment cigar leaves. The neutral aroma components in tobacco leaves were determined by distillation extraction-gas chromatography-mass spectrometry, and multivariate statistical methods were used for analysis and statistics.【Result】The total aroma and the contents of most neutral aroma components in cigar tobacco leaves were significantly increased after GL2 fermentation (P < 0.05), and the increased aroma substances mainly included olefins, ketones and alcohols. A total of 13 differentially neutral aroma components were selected by VIP > 1 and P < 0.05, and 9 of them were significantly up-regulated and positively correlated with tobacco leaf aroma. There were 7 species with significant positive correlation (P < 0.05), which were the key differential aroma components of 2, 6, 6-trimethyl-2-cyclohexene-1, 4-dione, 2, 6, 6-trimethyl-1, 4-cyclohexanedione, geraniyl acetone, acanthyl acetone, neophydiene, solanone and phytoalcohol. In addition, 4 different aroma components were significantly decreased and negatively correlated with tobacco leaf aroma, among which 2, 4-di-tert-butyl-6-nitrophenol was significantly negatively correlated with cigar tobacco aroma (P < 0.05). 2, 6, 6-trimethyl-2-cyclohexene-1, 4-dione, geranyl acetone, solanone and phytol contributed significantly to the aroma of fermented cigar tobacco leaves, resulting in a stronger overall dry and floral fragrances. As a result, they enriched the aroma and improved the sensory quality of cigar tobacco leaves.【Conclusion】Inoculation of B. safensis during cigar tobacco fermentation is beneficial for improving the quality of cigar tobacco leaves, which provide theoretical support for improving the fermentation quality of cigar tobacco leaves with biotechnology.

This study aimed to develop and validate a prediction model of cesarean following induction of labor (IOL). A nomogram for the prediction of cesarean following IOL for singleton, cephalic term deliveries was created by comparing combinations of ultrasonographic and nonultrasonographic factors in a retrospective manner using patient data collected from a Chinese hospital between July, 2017 and December, 2023. Model discrimination and calibration were evaluated using the area under the receiver operating characteristic curve (AUROC) and a calibration curve. Subsequently, decision curve analysis (DCA) was conducted to pinpoint the optimal probability threshold for the predictive model to exhibit practical significance for clinical decision-making. A total of 738 women were included. The inclusion of ultrasound factors yielded a higher AUC when combined with nonultrasonographic factors. Of the three ultrasonographic factors analyzed, the most predictive factor for cesarean following IOL was fetal head circumference. After generating a nomogram with eight validated factors, including maternal age, gestational age, height, prior caesarean delivery, previous vaginal delivery, modified Bishop score, body mass index at delivery, and fetal head circumference by ultrasound, the trained and validated AUC values were 0.826 (95% confidence interval 0.786–0.867) and 0.883 (95% confidence interval 0.839–0.926), respectively. Decision curve analysis indicated that the model provided net benefits of between 0% and 80% of the probability threshold, indicating the benefits of using the model to make decisions concerning patients who fall within the identified range of the probability threshold. Our nomogram based on obstetric factors and fetal head circumference as obtained by ultrasound could be used to help counsel women who are considering IOL. The model demonstrates favorable net benefits within a probability threshold range of 0 to 80%.

Clay minerals are widely distributed and are important components in sedimentary rocks. The identification and quantification of detrital and authigenic clay minerals have been hot topics recently due to the needs of petroleum geology, paleoclimate, and sedimentary history research. Detrital clay minerals exhibit the phenomenon of discrete grain boundaries, while authigenic clay minerals have various specific particle shapes. The differences in crystal structure of different clay mineral origins are reflected in the polytype character of clay minerals, especially for illite and chlorite. Different origins of clay minerals inherently have different chemical characteristics. Instead of focusing only on conventional techniques (scanning electron microscopy, X-ray diffraction, and geochemical analysis), here we review established approaches and introduce emerging analytical techniques (automated mineralogy techniques and artificial intelligence techniques) that can complement current methods. In addition, the applications of these techniques in illite age analysis, paleoclimate reconstruction, and reservoir properties are discussed. Further, different state-of-the-art techniques for clay mineral identification and quantification (e.g., scanning electron microscopy for specific petrographic characterization, X-ray diffraction for bulk crystal structure identification, etc.) are discussed. We propose that combining individual and bulk techniques obtained at multiple scales can provide novel insights for deciphering various clay mineral origins. Understanding the characteristics of clay minerals from different origins is of great importance to scientific issues such as shale oil and gas exploration.

Many different factors, such as species traits, socio-economic factors, geographical and environmental factors, can lead to specimen collection preference. This study aims to determine whether grassland specimen collection in China is preferred by species traits (i.e., plant height, flowering and fruiting period), environmental range (i.e., the temperature and precipitation range) and geographical range (i.e., distribution range and altitudinal range). Ordinary least squares models and phylogenetic generalized linear mixed models were used to analyze the relationships between specimen number and the explanatory variables. Random Forest models were then used to find the most parsimonious multivariate model. The results showed that interannual variation in specimen number between 1900 and 2020 was considerable. Specimen number of these species in southeast China was notably lower than that in northwest China. Environmental range and geographical range of species had significant positive correlations with specimen number. In addition, there were relatively weak but significant associations between specimen number and species trait (i.e., plant height and flowering and fruiting period). Random Forest models indicated that distribution range was the most important variable, followed by flowering and fruiting period, and altitudinal range. These findings suggest that future floristic surveys should pay more attention to species with small geographical range, narrow environmental range, short plant height, and short flowering and fruiting period. The correction of specimen collection preference will also make the results of species distribution model, species evolution and other works based on specimen data more accurate.

Abstract Background The United Nations (UN) Sustainable Development Goal − 3.2 aims to eliminate all preventable under-five mortality rate (U5MR). In China, government have made efforts to provide maternal health services and reduce U5MR. Hence, we aimed to explore maternal health service utilization in relation to U5MR in China and its provinces in 1990–2017. Methods We obtained data from Global Burden of Disease 2017, China Health Statistics Yearbook, China Statistical Yearbook, and Human Development Report China Special Edition. The trend of U5MR in each province of China from 1990 to 2017 was analyzed using Joinpoint Regression model. We measured the inequities in maternal health services using HEAT Plus, a health inequity measurement tool developed by the UN. The generalized estimating equation model was used to explore the association between maternal health service utilization (including prenatal screening, hospital delivery and postpartum visits) and U5MR. Results First, in China, the U5MR per 1000 live births decreased from 50 in 1990 to 12 in 2017 and the average annual percentage change (AAPC) was − 5.2 (p

The increased rate of antibiotic resistance strongly limits the resolution of Salmonella enterica serovar Typhimurium (S. Typhimurium) infection. Therefore, new strategies to control bacterial infections are urgently needed. Bacillus subtilis (B. subtilis) and its metabolites are desirable antibacterial agents. Here, we aimed to evaluate the antibacterial activity of the novel B. subtilis strain GXYX (No: PRJNA940956) crude lipopeptide against S. Typhimurium. In vitro, GXYX crude lipopeptides affected S. Typhimurium biofilm formation and swimming and attenuated the adhesion and invasion abilities of S. Typhimurium toward BHK-21 cells; in addition, it inhibited the mRNA expression of the filA, filC, csgA, and csgB genes, which are related to the adhesion and invasion ability of S. Typhimurium. In vivo, pretreatment with GXYX crude lipopeptide via intragastric administration improved the survival rate by 30%, which was related to reductions in organ bacterial loads and clinical signs in mice. Intragastric administration of GXYX crude lipopeptide significantly downregulated the mRNA levels of TNF-α, IL-1β, IL-12 and IL-6 in response to S. Typhimurium-induced inflammation compared with intraperitoneal injection. Moreover, it significantly improved the intestinal barrier-related gene (ZO-1, claudin-1, occludin-1) mRNA levels in intestinal tissue damaged by S. Typhimurium infection. In conclusion, GXYX crude lipopeptides were effective at reducing S. Typhimurium colonization, laying a foundation for the further development of novel antibacterial agents.

Streptococcus equi subsp. zooepidemicus (SEZ) is an opportunistic pathogen of both humans and animals. Quorum sensing (QS) plays an important role in the regulation of bacterial group behaviors. The aim of this study was to characterize the LuxS in SEZ and evaluate its impact on biofilm formation, pathogenesis and gene expression. The wild-type SEZ and its LuxS mutant (ΔluxS) were examined for growth, biofilm formation, virulence factors, and transcriptomic profiles. Our results showed that LuxS deficiency did not affect SEZ hemolytic activity, adhesion or capsule production. For biofilm assay demonstrated that mutation in the luxS gene significantly enhances biofilm formation, produced a denser biofilm and attached to a glass surface. RAW264.7 cell infection indicated that ΔluxS promoted macrophage apoptosis and pro-inflammatory responses. In mice infection, there was no significant difference in mortality between SEZ and ΔluxS. However, the bacterial load in the spleen of mice infected with ΔluxS was significantly higher than in those infected with SEZ. And the pathological analysis further indicated that spleen damage was more severe in the ΔluxS group. Moreover, transcriptomics analysis revealed significant alterations in carbon metabolism, RNA binding and stress response genes in ΔluxS. In summary, this study provides the first evidence of AI-2/LuxS QS system in SEZ and reveals its regulatory effects on biofilm formation, pathogenicity and gene expression.

Balancing ecological environment protection (EEP) and economic development (ED) (balance for short) is a difficult problem that must be solved in the development of modern society, particularly important for realizing UN Sustainable Development Goals. How to assess the regional balance situation and reveal the spatial and temporal heterogeneous characteristics of the balance (especially for the vast China) and its influencing factors are the primary scientific problems and realistic needs. Taking Zhejiang, Hunan and Gansu Provinces in the eastern, central and western region of China as a regional representative, an index system characterizing EEP and ED were established, which were processed by extreme difference method and entropy weight method. The coupling characteristics, stress factors and coordination type from 2010 to 2019 in the 3 provinces were assessed and analyzed by means of the coupling coordination model and the grey correlation degree model. Balance is the mission and responsibility of the spatial planning system for spatial planning is of the source, whole-region and comprehensiveness of public strategy, therefore, the balance strategies and its integration approaches are constructed in the 3 provincial spatial planning based on the assessment and analysis of balance characteristics. Research results show that: (1) the 3 provinces' coupling coordination degree is rising year by year, coordination type is more and more better indicating that the balance of EEP and ED is getting better and better, but coordination type differentiates at one level between 3 provinces at the east, central, western region of China, Zhejiang province is from nearby imbalance to primary coordination, Hunan Province is from nearby imbalance to narrow coordination, and Gansu Province is from medium imbalance to nearby imbalance. (2) The ED have same strong stress on EEP in the 3 provinces, and the constraints of EEP on ED are different, the current balance characteristics of Zhejiang, Hunan and Gansu province are the types of ecological environment pressure constraints primary coordination, ecological environment pressure constraints narrow coordination, and ecological environment condition constraints nearby imbalance. (3) The coordination types are the co-environmental pressure constraints primary coordination (Zhejiang Province), eco-environmental pressure constraints narrow coordination (Hunan Province) and eco-environmental condition constraints nearby imbalance (Gansu Province), and corresponding balanced planning strategy system are to promote ecological modernization, implement ecological industrialization and adhere to the ecological fundamentalization.

Biological specimens are fundamental for taxonomy and flora/fauna research. More importantly, they also play crucial roles in recording environmental impacts on morphology and behavior, which is vital for biodiversity research and conservation. However, there are few systematic studies on the patterns and drivers of bird specimen number at regional scales. This study is the first attempt to examine the relationships between bird specimen number and species traits as well as climate niche breadth in China, aiming to answer two questions: 1) how do species’ temperature niche breadth and precipitation niche breadth influence specimen number? 2) which trait is most associated with bird specimen number? The associations between bird specimen number and explanatory variables were examined using ordinary least squares, generalized linear models, phylogenetic generalized linear mixed models, and multiple comparisons. The results showed that Muscicapidae was the family with the highest specimen number, and Passeriformes was the order with the highest specimen number. Bird specimen number significantly increased with larger temperature niche breadth and precipitation niche breadth. Specimen number was also positively associated with geographic range size, habitat specificity, hunting vulnerability and clutch size, but negatively associated with body size. These findings suggest that future bird specimen collection should pay more attention to birds with limited ecological niches, large body sizes, and small clutch sizes. This research enhances the use of bird specimen data to study and preserve biodiversity.

Prioritization analysis with climate dynamics has become a critical, complex, and popular topic for conservation planning, providing opportunities for achieving co-benefits of climate stabilization, biodiversity conservation, and other goals. Here, we constructed a prioritization framework to inform the development of conservation policies or actions, further including the spatial heterogeneity and temporal stability characteristics of climate refugia. We then used China as a study area to identify priorities and assess the effectiveness of existing protected areas. Compared with the classical spatial prioritization approach, the priorities incorporating climatic characteristics cover, on average, 0.88 and 2.79 times more areas with low climatic velocities and high heterogeneity, respectively. By analyzing the proportion of various types of land use in the priorities, we found that grasslands play an essential role in species protection and climate regulation. Specifically, the percentage of grasslands in the priorities is about 30 %, ranking second to forests. Similarly, we identified prominent conservation gaps in China's protected area network, as evidenced by the insufficient emphasis on grassland and inadequate coverage of climate refugia. Our approach emphasizes the importance of integrating climate planning into conservation priorities and guiding conservation management and policy to achieve conservation goals in a climate-smart way.

A method for simultaneous determination of 53 anti-infective drugs such as quinolones and sulfonamides in cosmetics was established by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/ MS). The samples were dispersed with saturated sodium chloride, extracted by ultrasound with 1% acetonitrile formate solution, and centrifuged. 0.1% Formic acid aqueous solution (containing 1 mmol/L ammonium acetate) and 0.1% formic acid methanol solution were chose as mobile phase, gradient elution was used, and electrospray ion source, positive ion multi-reaction monitoring mode (MRM) were used for determination with quantitative external standard method. The results show that the linear fitting of the 53 banned raw materials is good, with the correlation coefficient greater than 0.991 0, and the detection limit of 0.01-0.1 μg/g. The average recovery rates of sulfonamides and quinolones are 80.84% to 115.09% at low, medium, and high spiked mass concentrations. Among the 100 batches of samples screened, 1 batch is detected to contain sulfamethoxazole. The method has good sensitivity, selectivity and accuracy, and can be used for the determination of 53 anti-infective drugs in cosmetics. [ABSTRACT FROM AUTHOR]