Since the outbreak of the COVID-19 epidemic, it has posed a great crisis to the health and economy of the world. The objective is to provide a simple deep-learning approach for predicting, modelling, and evaluating the time evolutions of the COVID-19 epidemic. The Dove Swarm Search (DSS) algorithm is integrated with the echo state network (ESN) to optimize the weight. The ESN-DSS model is constructed to predict the evolution of the COVID-19 time series. Specifically, the self-driven ESN-DSS is created to form a closed feedback loop by replacing the input with the output. The prediction results, which involve COVID-19 temporal evolutions of multiple countries worldwide, indicate the excellent prediction performances of our model compared with several artificial intelligence prediction methods from the literature (e.g., recurrent neural network, long short-term memory, gated recurrent units, variational auto encoder) at the same time scale. Moreover, the model parameters of the self-driven ESN-DSS are determined which acts as a significant impact on the prediction performance. As a result, the network parameters are adjusted to improve the prediction accuracy. The prediction results can be used as proposals to help governments and medical institutions formulate pertinent precautionary measures to prevent further spread. In addition, this study is not only limited to COVID-19 time series forecasting but also applicable to other nonlinear time series prediction problems.

The effects of reshock conditions, including the interface evolution state before reshock and the second shock intensity, on interface instability induced by two successive shocks propagating in the same direction are investigated via shock-tube experiments. It is observed that the reshock promotes the interface instability, and the post-reshock perturbation evolution relates to both the pre-reshock interface evolution state and second shock intensity. For the linear evolution of the twice-shocked interface, existing models perform poorly when either the pre-reshock interface shape effect or the secondary compression effect is pronounced, as current reduction factors fail to accurately describe these effects. Besides, the reshock-induced linear amplitude growth rate shows a non-monotonic dependence on the scaled pre-reshock amplitude, primarily due to the shape effect of the pre-reshock interface. For the post-reshock nonlinear evolution, the model proposed by Zhang & Guo (J. Fluid Mech., vol. 786, 2016, pp. 47–61) offers reasonable predictions when the second shock is weak. However, when the second shock is moderately strong, the model overestimates the bubble growth and underestimates the spike evolution under the influence of the significant secondary compression effect. Furthermore, empirical linear and nonlinear models capable of describing the dependence of the post-reshock evolution on reshock conditions are proposed based on the present experimental results and existing models.

The formation and evolution of large-scale deposits generated by mass movement are often closely related to tectonic and climatic conditions. Investigating deposits under the influence of complex geological conditions can aid in reconstructing paleoenvironmental characteristics and fluvial geomorphic evolution. The First Bend of the Yangtze River (FBYR), located in the Jinsha River basin in southwest China, represents a significant section characterized by abundant allochthonous deposits. We conducted a detailed investigation of the Hongwen allochthonous deposit (HAD) and the river sediments in the First Bend. Through terrain interpretation, dating, and paleoenvironmental analysis, the HAD was determined to be a complex deposit with multiple sources and stages (46.4–33.5 ka), formed under the combined influence of tectonic activity and climate. Three mass-movement events occurred during the interglacial stage of the last glacial period or its transitional period, coinciding with the rapid uplift stage of the Tibetan Plateau since the late Pleistocene. Prominent features of this period include significant rainfall and tectonic activities. By dating fluvial sediments and examining the evolution of the HAD, we revealed a river incision rate of 2.30 mm/yr for the Jinsha River, providing a basis for analyzing periodic river cutting and the development pattern of surface processes.

Depression is highly prevalent in haemodialysis patients, and diet might play an important role. Therefore, we conducted this cross-sectional study to determine the association between dietary fatty acids (FA) consumption and the prevalence of depression in maintenance haemodialysis (MHD) patients. Dietary intake was assessed using a validated FFQ between December 2021 and January 2022. The daily intake of dietary FA was categorised into three groups, and the lowest tertile was used as the reference category. Depression was assessed using the Patient Health Questionnaire-9. Logistic regression and restricted cubic spline (RCS) models were applied to assess the relationship between dietary FA intake and the prevalence of depression. As a result, after adjustment for potential confounders, a higher intake of total FA [odds ratio (OR)T3 vs. T1 = 1·59, 95 % confidence interval (CI) = 1·04, 2·46] and saturated fatty acids (SFA) (ORT3 vs. T1 = 1·83, 95 % CI = 1·19, 2·84) was associated with a higher prevalence of depressive symptoms. Significant positive linear trends were also observed (P < 0·05) except for SFA intake. Similarly, the prevalence of depression in MHD patients increased by 20% (OR = 1.20, 95% CI = 1.01–1.43) for each standard deviation increment in SFA intake. RCS analysis indicated an inverse U-shaped correlation between SFA and depression (Pnonlinear > 0·05). Additionally, the sensitivity analysis produced similar results. Furthermore, no statistically significant association was observed in the subgroup analysis with significant interaction. In conclusion, higher total dietary FA and SFA were positively associated with depressive symptoms among MHD patients. These findings inform future research exploring potential mechanism underlying the association between dietary FA and depressive symptoms in MHD patients.

The coupling of Richtmyer–Meshkov instability (RMI) and Kelvin–Helmholtz instability (KHI), referred to as RM-KHI, on a shock-accelerated inclined single-mode air–SF$_6$ interface is studied through shock-tube experiments, focusing on the evolution of the perturbation distributed along the inclined interface. To clearly capture the linear (overall linear to nonlinear) evolution of RM-KHI, a series of experiments with a weak (relatively strong) incident shock is conducted. For each series of experiments, various $\theta _{i}$ (angle between incident shock and equilibrium position of the initial interface) are considered. The nonlinear flow features manifest earlier and develop faster when $\theta _{i}$ is larger and/or shock is stronger. In addition, the interface with $\theta _{i}>0^{\circ }$ evolves obliquely along its equilibrium position under the effect of KHI. RMI dominates the early-time amplitude evolution regardless of $\theta _{i}$ and shock intensity, which arises from the discrepancy in the evolution laws between RMI and KHI. KHI promotes the post-early-stage amplitude growth and its contribution is related positively to $\theta _{i}$. An evident exponential-like amplitude evolution behaviour emerges in RM-KHI with a relatively strong shock and large $\theta _{i}$. The linear model proposed by Mikaelian (Phys. Fluids, vol. 6, 1994, pp. 1943–1945) is valid for RM-KHI within the linear period. In contrast, the adaptive vortex model (Sohn et al., Phys. Rev. E, vol. 82, 2010, p. 046711) can effectively predict both the interface morphology and overall amplitude evolutions from the linear to nonlinear regimes.

This experiment aimed to investigate the impacts of tributyrin (TB) dietary supplementation on serum biochemical indices and meat quality characteristics of longissimus thoracis et lumborum (LTL) muscle of lambs after weaning. Thirty healthy Small-Tailed Han female lambs (27.5 ± 4.1 kg; mean ± standard deviation) were randomly assigned to five treatments: basal diet (1) without TB, (2) with 0.5 g/kg TB, (3) with 1.0 g/kg TB, (4) with 2.0 g/kg TB or (5) with 4.0 g/kg TB. Each treatment consisted of six lambs, and the lambs were weaned on d 90 and were raised until d 165. Results showed that supplementing TB significantly promoted serum immunoglobulin concentrations of lambs such as immunoglobulins G, A and M. Besides, TB significantly increased muscle ether extract content, intermuscular fat length, pH value and redness but decreased lightness, drip loss and shear force. In addition, TB significantly elevated inosine-5ʹ-phosphate content and upregulated the relative expressions of genes related to lipid metabolism such as SREBP-1C, SCD, PPARγ, FAS and LPL. The mostly important, TB significantly enhanced essential amino acids (EAAs) and conjugated linoleic acids contents of the LTL muscle, despite it decreased total unsaturated fatty acids level. In conclusion, supplementing TB not only could promote the healthy status of weaned lambs via promoting serum immunity but also may improve nutritional quality of LTL muscle by improving EAA and conjugated linoleic acid contents.

The unsteady mechanism of unstart flow for an inlet with rectangular-to-elliptical shape transition (REST) under the off-design condition at a Mach of 4 is investigated using the delay detached eddy simulation method. With the help of numerical simulations, the unsteady dynamics, especially the low-frequency characteristics of the REST inlet unstart flow, as well as the self-sustaining mechanism, is investigated. The instantaneous flow illustrates the unsteady phenomena of the REST unstart flow, including the interaction between the cowl-closure leading edge (CLE) shock and the shear layer, breathing of the separation bubble, flapping of the separation shock, instability of the shear layer and vortex shedding along the shear layer. The spectral analysis reveals that the lower frequency dynamics is associated with the breathing of the separation bubble and the flapping motion of the separation shock wave, while the higher frequency is related to the instability of the shear layer affected by cowl-closure leading edge shock and the formation of shedding vortices. Further, coherence analysis shows that the contribution of these flow structures dominating the low-frequency dynamics couple with each other. Based on the dynamic mode decomposition results, the characteristics that contribute to the unsteady behaviour of unstart flow are summarized. The streamwise vortices downstream of the separation and the shedding vortices are believed to be the main driving force of the global low-frequency unsteadiness of the REST inlet unstart flow under the off-design condition. Moreover, the CLE shock plays an important role in the process during the dominant flow structure conversion from the backflow within the separation bubble into elongated streamwise structures.

The epidemiological and burden characteristics of nutritional deficiencies (ND) have been evolving, and it is crucial to identify geographical disparities and emerging trends. This study aimed to analyse the global, regional and national trends in the burden of ND over the past 30 years. Data were obtained from the Global Burden of Disease (GBD) 2019 database for the period 1990–2019. The study examined the incidence rates and disability-adjusted life years (DALY) of ND at various levels. Globally, the incidence rate of ND decreased from 2226·2 per 100 000 in 2019 to 2096·3 per 100 000 in the same year, indicating a decline of 5·8 %. The average annual percentage change (AAPC) was −0·21 (–0·31, −0·11). Similarly, DALY, prevalence and mortality rates of ND exhibited significant declines (AAPC = −3·21 (–3·45, −2·96), AAPC = −0·53 (–0·55, −0·51) and AAPC = −4·97 (–5·75, −4·19), respectively). The incidence rate of ND varied based on age group, sex, cause and geographical area. Moreover, a negative association was observed between incidence and the sociodemographic index. At the regional level, the South Asia and sub-Saharan Africa regions had the highest incidence rates of ND. In conclusion, the global incidence rate of ND showed a mixed pattern, while the DALY rate consistently declined. Additionally, prevalence and mortality rates of ND decreased between 1990 and 2019.

This paper retrospectively analysed the prevalence of macrolide-resistant Mycoplasma pneumoniae (MRMP) in some parts of China. Between January 2013 and December 2019, we collected 4,145 respiratory samples, including pharyngeal swabs and alveolar lavage fluid. The highest PCR-positive rate of M. pneumoniae was 74.5% in Beijing, the highest resistance rate was 100% in Shanghai, and Gansu was the lowest with 20%. The highest PCR-positive rate of M. pneumoniae was 74.5% in 2013, and the highest MRMP was 97.4% in 2019; the PCR-positive rate of M. pneumoniae for adults in Beijing was 17.9% and the MRMP was 10.48%. Among the children diagnosed with community-acquired pneumonia (CAP), the PCR-positive and macrolide-resistant rates of M. pneumoniae were both higher in the severe ones. A2063G in domain V of 23S rRNA was the major macrolide-resistant mutation, accounting for more than 90%. The MIC values of all MRMP to erythromycin and azithromycin were ≥ 64 μg/ml, and the MICs of tetracycline and levofloxacin were ≤ 0.5 μg/ml and ≤ 1 μg/ml, respectively. The macrolide resistance varied in different regions and years. Among inpatients, the macrolide-resistant rate was higher in severe pneumonia. A2063G was the common mutation, and we found no resistance to tetracycline and levofloxacin.

Soft drink consumption has become a highly controversial public health issue. Given the pattern of consumption in China, sugar-sweetened beverage is the main type of soft drink consumed. Due to containing high levels of fructose, a soft drink may have a deleterious effect on handgrip strength (HGS) due to oxidative stress, inflammation and insulin resistance. However, few studies show an association between soft drink consumption and HGS in adults. We aimed to investigate the association between soft drink consumption and longitudinal changes in HGS among a Chinese adult population. A longitudinal population-based cohort study (5-year follow-up, median: 3·66 years) was conducted in Tianjin, China. A total of 11 125 participants (56·7 % men) were enrolled. HGS was measured using a handheld digital dynamometer. Soft drink consumption (mainly sugar-containing carbonated beverages) was measured at baseline using a validated FFQ. ANCOVA was used to evaluate the association between soft drink consumption and annual change in HGS or weight-adjusted HGS. After adjusting for multiple confounding factors, the least square means (95 % CI) of annual change in HGS across soft drink consumption frequencies were −0·70 (–2·49, 1·09) for rarely drinks, −0·82 (–2·62, 0·97) for < 1 cup/week and −0·86 (–2·66, 0·93) for ≥ 1 cup/week (Pfor trend < 0·05). Likewise, a similar association was observed between soft drink consumption and annual change in weight-adjusted HGS. The results indicate that higher soft drink consumption was associated with faster HGS decline in Chinese adults.

As an environmental factor, temperature impacts the distribution of species and influences interspecific competition. The molecular chaperones encoded by small heat shock proteins (sHsps) are essential for rapid, appropriate responses to environmental stress. This study focuses on Hsp20.8, which encodes a temperature-responsive sHsp in Liriomyza trifolii, an insect pest that infests both agricultural and ornamental crops. Hsp20.8 expression was highest at 39℃ in L. trifolii pupae and adults, and expression levels were greater in pupae than in adults. Recombinant Hsp20.8 was expressed in Escherichia coli and conferred a higher survival rate than the empty vector to bacterial cells exposed to heat stress. RNA interference experiments were conducted using L. trifolii adults and prepupae and the knockdown of Hsp20.8 expression increased mortality in L. trifolii during heat stress. The results expand our understanding of sHsp function in Liriomyza spp. and the ongoing adaptation of this pest to climate change. In addition, this study is also important for predicting the distribution of invasive species and proposing new prevention and control strategies based on temperature adaptation.

In the soils of western Jilin Province in northeastern China, some significant gaps have been observed between the fraction of the soil existing as clay-size particles (<0.002 mm) and the amount attributable to crystalline clay minerals, and that the relative proportions of crystalline clay minerals to the total clay-size fraction (CP) apparently varies with latitude. The purpose of the present study was to identify the reason for this discrepancy and to explain the dependence on latitude. The grain sizes and mineral compositions of the whole soils from western Jilin Province, China, were analyzed by laser particle-size analysis (LPSA) and X-ray diffraction (XRD), and the <0.002 mm particle-size fraction was analyzed by XRD and X-ray fluorescence (XRF). The results confirmed that the percentage gaps between the clay fraction and clay minerals increased with increasing latitude. The theoretical illite percentage calculated from K2O content was compared with the illite percentage measured by XRD, and the results suggested that the measured illite accounted for only a small proportion of the theoretical illite. Structures of some special minerals below the identification threshold of XRD was suggested to be the reason for the percent gaps. The grain size and mineral crystallization both changed with latitude: the soil particle size and the CP decreased. In addition, clay minerals were more sensitive to climate than particle sizes were, and the CP of clay minerals in the soils within 0~180 cm depth all decreased with increasing latitude; however, the grain size showed patterns with latitude only in relatively shallow soil layers. The present study provides a reference and error analysis for the testing of clay minerals in alpine regions, and more suitable methods may be considered for development of clay-mineral testing in future studies.

The passive film of reinforcing steel in marine concrete is damaged by the infiltration of chloride and sulfate ions. Layered double hydroxide (LDH) can adsorb anions and release interlayer ions to form passive films due to its ion exchange property. A Mg-Al-NO3 layered double hydroxide/montmorillonite (LDH/Mnt) composite inhibitor was prepared by layer-by-layer self-assembly (LBL) of LDH and Mnt. The structure and morphology of the LDH/Mnt composites were characterized by X-ray diffraction (XRD), laser Raman spectroscopy, N2-adsorption/desorption measurements, and transmission electron microscopy (TEM). The LDH/Mnt composites, as inhibitors of chloride ions and sulfate ions, exhibited high slow-release efficiency. The mass ratio of LDH and Mnt affected the curing capacity of the synthesized composites, and the optimum mass ratio was LDH/Mnt = 1:1 for which slow-release efficiency reached 94.16%.

Soil aggregates consist of sand, silt, and clay size particles. Many of the clay size particles in soils are clay minerals, which actively influence soil behavior. The properties of clay minerals may change significantly as soil particle size decreases to the nanoscale; however, little information is available about these properties for the Ultisols in China. In the present study, the clay mineral components and structural characteristics of four particle-size fractions (i.e., <2000, 450–2000, 100–450, and 25–100 nm) of two Ultisol samples (Ult-1 and Ult-2) were investigated using elemental analysis, X-ray diffraction, Fouriertransform infrared spectroscopy, and thermal analysis. The molar SiO2 to Al2O3 ratios were lower in the nanoscale particle-size fraction (25–100 nm) than in the 450–2000 and <2000 nm fractions. This indicates greater desilicification and allitization of the smaller Ultisol particles. Furthermore, the Fe oxide and Al oxide contents increased and reached a maximum level in the 25–100 nm fraction of the two Ultisols. Goethite was mainly found in the 100–450 nm and 25–100 nm fractions. The dominant clay minerals in the Ultisol 25–100 nm fraction were kaolinite and illite with a small amount of a hydroxy-interlayered mineral in Ult-1 and gibbsite in Ult-2. The kaolinite crystallinity decreased as particle size decreased. The low crystallinity of the kaolinite in the A horizon 25–100 nm fraction was attributed to a reduction in the thickness of coherent scattering domains, as well as to decreases in OH groups and the dimensions of octahedral AlO6 sheets. A determination of the chemical and mineralogic properties of the different size fractions of the Ultisols is important to understand the desilicification and Al and Fe oxide enrichment mechanisms during soil formation. The significance of these results can help to reveal the nanoscale transformations of clay minerals. Analysis of clay mineral compositions in nanoparticles can provide the additional data needed to understand the adsorption and mobility of nutrients and pollutants.

A highly compressive effect would suppress the mixing of the shear layer in a convex wall jet. The spanwise distributed protrusions at the nozzle lip are employed to achieve mixing enhancement in this study. The mixing characteristics and enhancement mechanisms are numerically investigated by the delayed detached-eddy simulation method based on the two-equation shear-stress transport model. A widely applicable flow spatiotemporal analysis method, called proper orthogonal decomposition (POD), is used to gain further insight into the dynamical behaviours of the flow instability mode. The results reveal that the centrifugal effect maintains and amplifies the initial perturbations induced by the spanwise distributed heterogeneities, resulting in forced streamwise vortices. The instabilities induced by the streamwise vortices significantly increase the growth rate of the jet half-width and the shear layer vorticity thickness. The spanwise wavelength of the streamwise vortices is consistent with the spanwise distributed forced excitation. In addition, the spanwise meandering motion of the streamwise vortices is observed, which is usually associated with the streamwise travelling wave. This is further confirmed by the POD analysis of the spanwise velocity fluctuation in both stream-radial and stream-span sections. Also, the spatial distributions of the POD modes with the highest energy provide information on the secondary instability modes. Both sinuous and varicose types of disturbances are observed in the unforced jet, whereas the forced jet seems to be dominated by the sinuous type instability, which is more easily excited than the varicose type instability. Moreover, the turbulence intensity in the forced jet is also significantly enhanced as expected due to the earlier and stronger streamwise vortices and associated instabilities. The enhanced turbulent characteristics of the highly compressible condition tend to be isotropic, whereas in the unforced jet, it is anisotropic due to the strong compressibility suppressing the spanwise turbulent fluctuations.

Animal studies have shown that capsaicin plays a positive role in weight management. However, the results in human research are controversial. Therefore, the present systematic review and meta-analysis aimed to evaluate the effect of capsaicin on weight loss in adults. We searched PubMed, Embase, China Biomedical Literature Database (CBM), Cochrane library and clinical registration centre, identifying all randomised controlled trials (RCT) published in English and Chinese to 3 May 2022. A random-effect model was used to calculate the weighted mean difference (WMD) and 95 % CI. Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I2). Statistical analyses were performed using STATA version 15.1. P-values < 0·05 were considered as statistically significant. From 2377 retrieved studies, fifteen studies were finally included in the meta-analyses. Fifteen RCT with 762 individuals were included in our meta-analysis. Compared with the control group, the supplementation of capsaicin resulted in significant reduction on BMI (WMD: −0·25 kg/m2, 95 % CI = –0·35, –0·15 kg/m2, P < 0·05), body weight (BW) (WMD: −0·51 kg, 95 % CI = –0·86, –0·15 kg, P < 0·05) and waist circumference (WC) (WMD: −1·12 cm, 95 % CI = –2·00, –0·24 cm, P < 0·05). We found no detrimental effect of capsaicin on waist-to-hip ratio (WMD: −0·05, 95 % CI = –0·17, 0·06, P > 0·05). The current meta-analysis suggests that capsaicin supplementation may have rather modest effects in reducing BMI, BW and WC for overweight or obese individuals.