Multiplex cerebrospinal fluid proteomics identifies biomarkers for diagnosis and prediction of Alzheimer's disease.

Recent expansion of proteomic coverage opens unparalleled avenues to unveil new biomarkers of Alzheimer's disease (AD). Among 6,361 cerebrospinal fluid (CSF) proteins analysed from the ADNI database, YWHAG performed best in diagnosing both biologically (AUC = 0.969) and clinically (AUC = 0.857) defined AD. Four- (YWHAG, SMOC1, PIGR and TMOD2) and five- (ACHE, YWHAG, PCSK1, MMP10 and IRF1) protein panels greatly improved the accuracy to 0.987 and 0.975, respectively. Their superior performance was validated in an independent external cohort and in discriminating autopsy-confirmed AD versus non-AD, rivalling even canonical CSF ATN biomarkers. Moreover, they effectively predicted the clinical progression to AD dementia and were strongly associated with AD core biomarkers and cognitive decline. Synaptic, neurogenic and infectious pathways were enriched in distinct AD stages. Mendelian randomization did not support the significant genetic link between CSF proteins and AD. Our findings revealed promising high-performance biomarkers for AD diagnosis and prediction, with implications for clinical trials targeting different pathomechanisms.

High-Throughput SFC-MS/MS Method to Measure EPSA and Predict Human Permeability.

Permeability is a key factor driving the absorption of orally administered drugs. In early discovery, the efficient evaluation of permeability, particularly for compounds violating Lipinski's Rule of 5, remains challenging. Addressing this, we established a high-throughput method to measure the experimental polar surface area (HT-EPSA) as an in vitro surrogate to measure permeability. Compared to earlier methods, HT-EPSA significantly reduces data acquisition time with enhanced sensitivity, selectivity, and data quality. In the effort of translating EPSA to human in vitro and in vivo passive permeability, we demonstrated the application of EPSA for predicting Caco-2 cell and human intestinal permeability, showing improvements over topological polar surface area and the parallel artificial membrane permeability assay for rank-ordering permeability in a proteolysis targeting chimera case study. The HT-EPSA method is expected to be highly beneficial in guiding early stage compound rank-ordering, faster decision-making, and in predicting in vitro and/or in vivo human intestinal permeability.

Shift work effects on incident neuropsychiatric disorders and shift work tolerance.

BACKGROUND: Shift work is associated with susceptibility to several neuropsychiatric disorders. This study aims to investigate the effect of shift work on the incidence of neuropsychiatric disorders, and highlighting how individual variability may influence the association. METHODS: UK Biobank participants with employment information were included. Cox survival was conducted in main and subgroup analyses. Correlation analyses explored the impact of shift work on brain structures, and mediation analyses were performed to elucidate the shared underlying mechanisms. Shift work tolerance was evaluated through survival analyses contrasting the risks associated with five neuropsychiatric disorders in shift versus non-shift workers across different demographic or occupational strata. RESULTS: The analysis encompassed 254,646 participants. Shift work was associated with higher risk of dementia (HR 1.29, 95 % CI 1.10-1.52), anxiety (1.08, 1.01-1.15), depression (1.29, 1.22-1.36), and sleep disorders (1.18, 1.09-1.28), but not stroke (p = 0.20). Shift work was correlated with decreasing volume of various brain regions, particularly in thalamus, lateral orbitofrontal, and middle temporal. Mediation analysis revealed that increased immune response and glucose levels are common pathways linking shift work to these disorders. We observed diversity in shift work tolerance across different individual characteristics, among which socioeconomic status and length of working hours were the most essential. LIMITATIONS: Self-reported employment information may cause misclassification and recall bias. And since we focused on the middle-aged population, the conclusions may not be representative of younger or older populations. CONCLUSIONS: Our findings indicated the need to monitor shift worker health and provide personalized management to help adapt to shift work.

Whole exome sequencing analysis identifies genes for alcohol consumption.

Alcohol consumption is a heritable behavior seriously endangers human health. However, genetic studies on alcohol consumption primarily focuses on common variants, while insights from rare coding variants are lacking. Here we leverage whole exome sequencing data across 304,119 white British individuals from UK Biobank to identify protein-coding variants associated with alcohol consumption. Twenty-five variants are associated with alcohol consumption through single variant analysis and thirteen genes through gene-based analysis, ten of which have not been reported previously. Notably, the two unreported alcohol consumption-related genes GIGYF1 and ANKRD12 show enrichment in brain function-related pathways including glial cell differentiation and are strongly expressed in the cerebellum. Phenome-wide association analyses reveal that alcohol consumption-related genes are associated with brain white matter integrity and risk of digestive and neuropsychiatric diseases. In summary, this study enhances the comprehension of the genetic architecture of alcohol consumption and implies biological mechanisms underlying alcohol-related adverse outcomes.

Large-scale whole-exome sequencing analyses identified protein-coding variants associated with immune-mediated diseases in 350,770 adults.

The genetic contribution of protein-coding variants to immune-mediated diseases (IMDs) remains underexplored. Through whole exome sequencing of 40 IMDs in 350,770 UK Biobank participants, we identified 162 unique genes in 35 IMDs, among which 124 were novel genes. Several genes, including FLG which is associated with atopic dermatitis and asthma, showed converging evidence from both rare and common variants. 91 genes exerted significant effects on longitudinal outcomes (interquartile range of Hazard Ratio: 1.12-5.89). Mendelian randomization identified five causal genes, of which four were approved drug targets (CDSN, DDR1, LTA, and IL18BP). Proteomic analysis indicated that mutations associated with specific IMDs might also affect protein expression in other IMDs. For example, DXO (celiac disease-related gene) and PSMB9 (alopecia areata-related gene) could modulate CDSN (autoimmune hypothyroidism-, psoriasis-, asthma-, and Graves' disease-related gene) expression. Identified genes predominantly impact immune and biochemical processes, and can be clustered into pathways of immune-related, urate metabolism, and antigen processing. Our findings identified protein-coding variants which are the key to IMDs pathogenesis and provided new insights into tailored innovative therapies.

Whole exome sequencing analyses reveal novel genes in telomere length and their biomedical implications.

Telomere length is a putative biomarker of aging and is associated with multiple age-related diseases. There are limited data on the landscape of rare genetic variations in telomere length. Here, we systematically characterize the rare variant associations with leukocyte telomere length (LTL) through exome-wide association study (ExWAS) among 390,231 individuals in the UK Biobank. We identified 18 robust rare-variant genes for LTL, most of which estimated effects on LTL were significant (> 0.2 standard deviation per allele). The biological functions of the rare-variant genes were associated with telomere maintenance and capping and several genes were specifically expressed in the testis. Three novel genes (ASXL1, CFAP58, and TET2) associated with LTL were identified. Phenotypic association analyses indicated significant associations of ASXL1 and TET2 with cancers, age-related diseases, blood assays, and cardiovascular traits. Survival analyses suggested that carriers of ASXL1 or TET2 variants were at increased risk for cancers; diseases of the circulatory, respiratory, and genitourinary systems; and all-cause and cause-specific deaths. The CFAP58 carriers were at elevated risk of deaths due to cancers. Collectively, the present whole exome sequencing study provides novel insights into the genetic landscape of LTL, identifying novel genes associated with LTL and their implications on human health and facilitating a better understanding of aging, thus pinpointing the genetic relevance of LTL with clonal hematopoiesis, biomedical traits, and health-related outcomes.

The role of DsbA and PepP genes in the environmental tolerance and virulence factors of Cronobacter sakazakii.

Cronobacter sakazakii, an opportunity foodborne pathogen, could contaminate a broad range of food materials and cause life-threatening symptoms in infants. The bacterial envelope structure contribute to bacterial environment tolerance, biofilm formation and virulence in various in Gram-negative bacteria. DsbA and PepP are two important genes related to the biogenesis and stability of bacterial envelope. In this study, the DsbA and PepP were deleted in C. sakazakii to evaluate their contribution to stress tolerance and virulence of the pathogen. The bacterial environment resistance assays showed DsbA and PepP are essential in controlling C. sakazakii resistance to heat and desiccation in different mediums, as well as acid, osmotic, oxidation and bile salt stresses. DsbA and PepP also played an important role in regulating biofilm formation and motility. Furthermore, DsbA and PepP deletion weaken C. sakazakii adhesion and invasion in Caco-2, intracellular survival and replication in RAW 264.7. qRT-PCR results showed that DsbA and PepP of C. sakazakii played roles in regulating the expression of several genes associated with environment stress tolerance, biofilm formation, bacterial motility and cellular invasion. These findings indicate that DsbA and PepP played an important regulatory role in the environment resisitance, biofilm formation and virulence of C. sakazakii, which enrich understanding of genetic determinants of adaptability and virulence of the pathogen.

Cep57 regulates human centrosomes through multivalent interactions.

Human Cep57 is a coiled-coil scaffold at the pericentriolar matrix (PCM), controlling centriole duplication and centrosome maturation for faithful cell division. Genetic truncation mutations of Cep57 are associated with the mosaic-variegated aneuploidy (MVA) syndrome. During interphase, Cep57 forms a complex with Cep63 and Cep152, serving as regulators for centrosome maturation. However, the molecular interplay of Cep57 with these essential scaffolding proteins remains unclear. Here, we demonstrate that Cep57 undergoes liquid-liquid phase separation (LLPS) driven by three critical domains (NTD, CTD, and polybasic LMN). In vitro Cep57 condensates catalyze microtubule nucleation via the LMN motif-mediated tubulin concentration. In cells, the LMN motif is required for centrosomal microtubule aster formation. Moreover, Cep63 restricts Cep57 assembly, expansion, and microtubule polymerization activity. Overexpression of competitive constructs for multivalent interactions, including an MVA mutation, leads to excessive centrosome duplication. In Cep57-depleted cells, self-assembly mutants failed to rescue centriole disengagement and PCM disorganization. Thus, Cep57's multivalent interactions are pivotal for maintaining the accurate structural and functional integrity of human centrosomes.

Gamification of dermatoscopy education using a smartphone mobile platform: A pilot study.

Background: Dermatoscopy is a noninvasive method of examining skin lesions under high magnification, gradually replacing the need for invasive biopsies. Training is required to gain clinical competency. Gamification employs game-like elements to enhance education engagement and is an engaging means of delivering medical education. We sought to use gamification and a mobile-based platform to deliver dermatoscopy education to physicians. Methods: We developed SKIN@GoPRIME, an interactive smartphone platform. Thirty physician participants were randomly assigned to watch an online dermatoscopy lecture or to use SKIN@GoPRIME. Twenty-eight participants completed prelearning and postlearning quizzes and provided feedback on SKIN@GoPRIME. Results: Users of SKIN@GoPRIME demonstrated a significant 1.71-point mean score improvement (P = .0018). The group that watched the online dermatoscopy lecture had a higher 2.36-point mean score improvement (P = .00021). Both family medicine and internal medicine physicians demonstrated a significant mean score increase of 1.29 (P = .049) and 2.14 (P = .023), respectively, after using SKIN@GoPRIME. Based on feedback, 83% believed that SKIN@GoPRIME can be used to acquire the applied competencies required for their job scope. Discussion and Conclusion: SKIN@GoPRIME, a novel learning tool via gamification effectively delivers dermatoscopy education, although it is not shown to be more effective than lectures. Larger studies are required to further validate the effectiveness of gamified learning techniques in dermatoscopy education. Future studies should involve the optimization of SKIN@GoPRIME to more effectively deliver dermatoscopy education.

[Multi Scenario Carbon Peak Prediction and Emission Reduction Path Analysis of Xi'an Hi-tech Zone].

The fifth session of the 13th National People's Congress proposed to be committed to promoting carbon peaking and carbon neutrality, promoting the comprehensive green and low-carbon transformation of the economy and society and achieving high-quality development. As an important scientific and technological innovation and industrial cluster in Shaanxi Province, the economic development of the Xi'an Hi-tech Zone largely relies on energy consumption, making the task of carbon reduction particularly challenging. Firstly, taking the Xi'an Hi-tech Zone as the research object, through systematic accounting of carbon emissions within the park, we analyzed the current carbon emission status of enterprises in different energy types and industries. Then, using the Kaya model, multiple independent carbon peak scenarios were set up to predict the total carbon emissions and peak time under different scenarios. Finally, based on the development characteristics of the Xi'an Hi-tech Zone, we scientifically selected corresponding carbon emission reduction paths and provided reasonable emission reduction suggestions. The results showed that the proportion of carbon emissions consumed by electricity was currently the highest, and the share was increasing yearly. Industrial carbon emissions had always been dominant, and the development of the tertiary industry was becoming increasingly prosperous. In the scenario prediction, the carbon emission factor scenario, energy intensity scenario, and economic level scenario could reach the carbon peak by 2030. Among them, the economic development level had the greatest impact on the peak and time of the future carbon peak in the Xi'an Hi-tech Zone, whereas the industrial structure scenario, energy source structure scenario, and population size scenario had no peak before 2030. The future emission reduction path mainly started from decarbonization of the power sector, stable and high-quality economic development, green upgrading of energy and industrial structure, and building a green transportation system. This can reserve more preparation time for achieving carbon neutrality and provide decision-making reference for the low-carbon development of industrial parks in China.

Silver Nanoparticles Encapped by Dihydromyricetin: Optimization of Green Synthesis, Characterization, Toxicity, and Anti-MRSA Infection Activities for Zebrafish (Danio rerio).

To achieve the environmentally friendly and rapid green synthesis of efficient and stable AgNPs for drug-resistant bacterial infection, this study optimized the green synthesis process of silver nanoparticles (AgNPs) using Dihydromyricetin (DMY). Then, we assessed the impact of AgNPs on zebrafish embryo development, as well as their therapeutic efficacy on zebrafish infected with Methicillin-resistant Staphylococcus aureus (MRSA). Transmission electron microscopy (TEM) and dynamic light-scattering (DLS) analyses revealed that AgNPs possessed an average size of 23.6 nm, a polymer dispersity index (PDI) of 0.197 ± 0.0196, and a zeta potential of -18.1 ± 1.18 mV. Compared to other published green synthesis products, the optimized DMY-AgNPs exhibited smaller sizes, narrower size distributions, and enhanced stability. Furthermore, the minimum concentration of DMY-AgNPs required to affect zebrafish hatching and survival was determined to be 25.0 µg/mL, indicating the low toxicity of DMY-AgNPs. Following a 5-day feeding regimen with DMY-AgNP-containing food, significant improvements were observed in the recovery of the gills, intestines, and livers in MRSA-infected zebrafish. These results suggested that optimized DMY-AgNPs hold promise for application in aquacultures and offer potential for further clinical use against drug-resistant bacteria.

Trilaciclib dosage in Chinese patients with extensive-stage small cell lung cancer: a pooled pharmacometrics analysis.

This study aimed to analyze potential ethnic disparities in the dose-exposure-response relationships of trilaciclib, a first-in-class intravenous cyclin-dependent kinase 4/6 inhibitor for treating chemotherapy-induced myelosuppression in patients with extensive-stage small cell lung cancer (ES-SCLC). This investigation focused on characterizing these relationships in both Chinese and non-Chinese patients to further refine the dosing regimen for trilaciclib in Chinese patients with ES-SCLC. Population pharmacokinetic (PopPK) and exposure-response (E-R) analyses were conducted using pooled data from four randomized phase 2/3 trials involving Chinese and non-Chinese patients with ES-SCLC. PopPK analysis revealed that trilaciclib clearance in Chinese patients was approximately 17% higher than that in non-Chinese patients with ES-SCLC. Sex and body surface area influenced trilaciclib pharmacokinetics in both populations but did not exert a significant clinical impact. E-R analysis demonstrated that trilaciclib exposure increased with a dosage escalation from 200 to 280 mg/m2, without notable changes in myeloprotective or antitumor efficacy. However, the incidence of infusion site reactions, headaches, and phlebitis/thrombophlebitis rose with increasing trilaciclib exposure in both Chinese and non-Chinese patients with ES-SCLC. These findings suggest no substantial ethnic disparities in the dose-exposure-response relationship between Chinese and non-Chinese patients. They support the adoption of a 240-mg/m2 intravenous 3-day or 5-day dosing regimen for trilaciclib in Chinese patients with ES-SCLC.

The application of heating film to hands reduces the decline in manual dexterity performance associated with cold exposure.

PURPOSE: Exposure to cold temperatures decreases finger temperature (Tfing) and dexterity. Decreased manual function and dexterity can be serious safety risks, especially in tasks that require fine motor movements that must be performed outdoors. The aim of this study was to determine whether hand heating with a minimal power requirement (14.8 W) results in a smaller reduction in Tfing and manual dexterity performance during mild cold exposure compared to a non-heated control condition. METHODS: In a randomized crossover design, twenty-two healthy participants were exposed to a moderately cold environment (5  ºC) for 90 min. One condition had no intervention (CON), while the other had the palmar and dorsal hands heated (HEAT) by using electric heating films. Tfing and cutaneous vascular conductance (CVC) were continuously monitored using laser Doppler flowmetry. Manual dexterity performance and cognitive function were assessed by the Grooved Pegboard Test (GPT) and Stroop Color-Word (SCW) test, respectively, during the baseline period and every 30 min during the cold exposure. RESULTS: After the cold exposure, Tfing was higher in HEAT relative to CON (CON 9.8 vs. HEAT 13.7 ºC, p < 0.0001). GPT placing time, as an index of dexterity performance, was also shorter in HEAT by 14.5% (CON 69.10 ± 13.08 vs. HEAT 59.06 ± 7.99 s, p < 0.0001). There was no difference in CVC between the two conditions during the cold exposure (p > 0.05 for all). Cognitive function was similar between two conditions (p > 0.05 for all). CONCLUSION: The proposed hand heating method offers a practical means of heating fingers to maintain dexterity throughout prolonged cold exposure.

[Comparative study on excretion of Shuganning Injection and Scutellariae Radix extract in bile, urine, and feces of rats].

Scutellariae Radix extract is one of the important components in Shuganning Injection. In this study, an ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) method was established for simultaneously determining five components in Shuganning Injection and Scutellariae Radix extract in bile, urine, and feces of rats, so as to reveal the difference in the excretion process of Shuganning Injection and Scutellariae Radix extract in rats and explore the law of the excretion process of the five components in vivo before and after the compatibility of Scutellariae Radix. Rats were injected with Shuganning Injection and Scutellariae Radix extract(4.2 mL·kg~(-1)), respectively, and the excretion of baicalin, baicalein, oroxylin A, oroxylin A-7-O-ß-D-glucuronide, and scutellarin in bile, urine, and feces of rats in 24 h was observed. The results showed that except for baicalin, the other four index components were excreted as prototype components in a high proportion after intravenous injection of Shuganning Injection and Scutellariae Radix extract in rats, respectively. The excretion of each component was relatively high in urine and less in feces and bile. After the compatibility of Scutellariae Radix extract, the accumulative excretion of five index components in rats all decreased. Among them, the cumulative excretion of baicalein in bile, urine, and feces significantly decreased by 26.67%, 48.11%, and 31.01%. The cumulative excretion of baicalin in bile, urine, and feces decreased significantly by 70.69%, 19.43%, and 31.22%. The result showed that the five index components in Scutellariae Radix extract were mainly excreted by the kidneys, and other components in Shuganning Injection delayed the excretion process and prolonged the residence time. This study is of great significance for elucidating the compatibility rationality of Shuganning Injection.

Large-scale whole-exome sequencing of neuropsychiatric diseases and traits in 350,770 adults.

While numerous genomic loci have been identified for neuropsychiatric conditions, the contribution of protein-coding variants has yet to be determined. Here we conducted a large-scale whole-exome-sequencing study to interrogate the impact of protein-coding variants on 46 neuropsychiatric diseases and 23 traits in 350,770 adults from the UK Biobank. Twenty new genes were associated with neuropsychiatric diseases through coding variants, among which 16 genes had impacts on the longitudinal risks of diseases. Thirty new genes were associated with neuropsychiatric traits, with SYNGAP1 showing pleiotropic effects across cognitive function domains. Pairwise estimation of genetic correlations at the coding-variant level highlighted shared genetic associations among pairs of neurodegenerative diseases and mental disorders. Lastly, a comprehensive multi-omics analysis suggested that alterations in brain structures, blood proteins and inflammation potentially contribute to the gene-phenotype linkages. Overall, our findings characterized a compendium of protein-coding variants for future research on the biology and therapeutics of neuropsychiatric phenotypes.

Genetic associations of protein-coding variants in venous thromboembolism.

Previous genetic studies of venous thromboembolism (VTE) have been largely limited to common variants, leaving the genetic determinants relatively incomplete. We performed an exome-wide association study of VTE among 14,723 cases and 334,315 controls. Fourteen known and four novel genes (SRSF6, PHPT1, CGN, and MAP3K2) were identified through protein-coding variants, with broad replication in the FinnGen cohort. Most genes we discovered exhibited the potential to predict future VTE events in longitudinal analysis. Notably, we provide evidence for the additive contribution of rare coding variants to known genome-wide polygenic risk in shaping VTE risk. The identified genes were enriched in pathways affecting coagulation and platelet activation, along with liver-specific expression. The pleiotropic effects of these genes indicated the potential involvement of coagulation factors, blood cell traits, liver function, and immunometabolic processes in VTE pathogenesis. In conclusion, our study unveils the valuable contribution of protein-coding variants in VTE etiology and sheds new light on its risk stratification.

Using Protein Design and Directed Evolution to Monomerize a Bright Near-Infrared Fluorescent Protein.

The small ultrared fluorescent protein (smURFP) is a bright near-infrared (NIR) fluorescent protein (FP) that forms a dimer and binds its fluorescence chromophore, biliverdin, at its dimer interface. To engineer a monomeric NIR FP based on smURFP potentially more suitable for bioimaging, we employed protein design to extend the protein backbone with a new segment of two helices that shield the original dimer interface while covering the biliverdin binding pocket in place of the second chain in the original dimer. We experimentally characterized 13 designs and obtained a monomeric protein with a weak fluorescence. We enhanced the fluorescence of this designed protein through two rounds of directed evolution and obtained designed monomeric smURFP (DMsmURFP), a bright, stable, and monomeric NIR FP with a molecular weight of 19.6 kDa. We determined the crystal structures of DMsmURFP both in the apo state and in complex with biliverdin, which confirmed the designed structure. The use of DMsmURFP in in vivo imaging of mammalian systems was demonstrated. The backbone design-based strategy used here can also be applied to monomerize other naturally multimeric proteins with intersubunit functional sites.

Antagonistic Effects, Sources, and Distribution of Selenium and Toxic Metals in Fish from Selenium-Rich and High Cadmium Areas, Dashan Region, China.

The Gongxin River is one of the main rivers in the Dashan Region of Anhui Province in China, which is a Se-rich and high-Cd area, but no research has focused on the concentration, source, antagonism, and health risks of Se and TMs in fish. In this study, 120 fish samples (14 species), 24 sediment samples, and 24 water samples were collected to investigate the antagonistic effects, sources, and health risks of TMs and Se in fish from a typical selenium-rich and high cadmium region. Zn and Se in fish from the Gongxin River were higher than in the background, which might be attributed to the different feeding habits of different fish species. The apparent antagonism between Se and Cu, Pb, and Cd was explored, and the results showed that 30%, 75%, and 100% of the Se/Cu, Se/Pb, and Se/Cd ratios were greater than one, indicating that Cu, Pb, and Cd in fish might be combined with or detoxicated by Se. The source analysis of the elements showed that the geological background was the source of TMs and Se in fish samples. The amounts of Se and TMs were all within China's acceptable level guidelines, signifying no harm to citizens from eating fish.

Cognitive frailty and its association with disability among Chinese community-dwelling older adults: a cross-sectional study.

BACKGROUND: There are a variety of determinants that are key to functional disability of older adults. However, little is known regarding the relationship between cognitive frailty and disability among older people. The aims of this study were to examine the associations between cognitive frailty and its six components with instrumental activities of daily living (IADL) functioning in community-dwelling older adults. METHODS: A total of 313 community-dwelling older adults (aged ≥ 65 years) were recruited from eight community centers in central China. Cognitive frailty was operationalized using the Mini-Mental State Examination for the evaluation of cognitive status and the Fried criteria for the evaluation of physical frailty. The outcome was functional disability assessed by the IADL scale. The association between cognitive frailty, as well as its components, and IADL limitations was identified by conducting binary logistic regression analysis. RESULTS: The prevalence of cognitive frailty was 8.9% in this study. The results showed that cognitive frailty (OR = 22.86) and frailty without cognitive impairment (OR = 8.15) were associated with IADL limitations. Subdimensions of cognitive frailty, exhaustion, weakness, low physical activity and cognitive impairment components were independently associated with IADL limitations. CONCLUSION: Cognitive frailty was associated with a higher prevalence of disability. Interventions for improving cognitive frailty should be developed to prevent IADL disability among community-dwelling older adults in China.