Morphology and classification of the second mesiobuccal canal in maxillary first molars: a cone-beam computed tomography analysis in a Chinese population.

BACKGROUND: Understanding the tooth anatomy is crucial for ensuring effective endodontic treatment. This study investigated the root canal morphology of the second mesiobuccal (MB2) canal in maxillary first molars (MFMs) in a Chinese population using cone-beam computed tomography (CBCT). METHODS: This study evaluated 486 MFMs with MB2 canals from 285 participants undergoing CBCT examination and determined the Vertucci's classification and position of the MB2 canal orifice. The prevalence of the MB2 canal was correlated with the sex, age, and tooth side. The correlations between the prevalence of the MB2 canal and sex and tooth side were assessed using the Fisher's exact test. The chi-square test was used for evaluating the correlation between the prevalence of the MB2 canal and age. RESULTS: The number of type II, III, IV, V, VI, VII, and other root canals in the MFMs was 30.9%, 0.6%, 65.0%, 1.2%, 1.2%, 0.4%, and 0.6%, respectively. Among the 201 cases with bilateral inclusion, 87.6% showed consistent canal configuration. Results of the first clear apparent position (FCAP) of the MB2 canals showed that 434, 44, and 3 teeth had FCAP at the upper, middle, and bottom one-third of the root, respectively. The FCAPs of the MB2 canal in the MFMs with types II, IV, and VI, as well as types III and V canals showed significant differences (p<0.05). The horizontal distance between the MB1 and MB2 canal orifices in the type II canals of MFMs was significantly lesser than those in the type IV canals of MFMs (p < 0.01). The longitudinal distance between the pulp chamber floor plane and MB2 canal orifice significantly correlated with age (p < 0.05). CONCLUSIONS: The morphology of the mesiobuccal root canal in the MFMs is complex. Complete understanding of the anatomical morphology of the root canal combined with the CBCT and dental operating microscope is necessary for the accurate detection of the MB2 canal and consequently improved success rate of root canal treatment. Our study findings can help endodontists improve endodontic treatment outcomes.

Reciprocal and Dynamic Associations between Social Isolation, Loneliness, and Disability among Chinese Older Adults.

OBJECTIVES: This study aimed to examine reciprocal and dynamic associations between Social Isolation (SI), loneliness, and disability among Chinese older adults. DESIGN: This is a prospective cohort study. SETTING AND PARTICIPANTS: The global trend of population aging has resulted in a significant rise in the prevalence of disabilities, SI, and loneliness among older adults. These factors can severely impact the health and well-being of older adults. Therefore, it is crucial to implement more efficient interventions aimed at reducing disabilities, addressing SI, and combating loneliness among older adults in order to improve their overall health and well-being. METHODS: Using a large, nationally representative sample spanning 16 years, we employed the general cross-lagged panel model to explore the relationships among 50,348 older adults with a mean age of 81.83 at baseline. Disability was measured by a comprehensive index tool that incorporated multiple dimensions. SI was measured using an SI index, and loneliness was evaluated using a single-item measure. RESULTS: SI emerged as a stronger predictor of disability than loneliness. Longitudinal analysis revealed accumulative disadvantages in the association between SI and disability. Additionally, disability was found to contribute to increased SI and loneliness. However, our study did not detect any variance in the strength of the cross-lagged effects between social isolation and disability. CONCLUSIONS AND IMPLICATIONS: The findings suggest that reducing SI is crucial for reducing disability among older adults. Initiating early interventions to minimize initial SI could aid in preventing later-life disability. Additionally, addressing disabilities may positively impact the reduction of loneliness and SI within this population.

Effectiveness and safety of intracardiac electrocardiogram guidance for epicutaneo-cava catheters via the lower extremity in preterm infants: a retrospective study.

INTRODUCTION: In recent years, intracardiac electrocardiogram (IC-ECG) technology has been widely used for epicutaneo-cava catheter (ECC) placement and has shown many potential advantages. However, evidence about the quantitative changes, effectiveness, and safety of IC-ECG for lower extremity ECC is sparse. This study aimed to explore the quantitative changes in IC-ECG for lower extremity ECC and determine its effectiveness and safety. METHODS: A retrospective study was conducted on 303 premature infants who underwent successful IC-ECG-guided lower extremity ECC placement between January 2019 and December 2021. All patients underwent chest X-ray postoperatively to verify the position of the catheter tip. The amplitudes of the surface electrocardiogram and IC-ECG QRS waves and the difference between the two amplitudes were measured. The effectiveness (matching rate between IC-ECG and chest X-ray) and safety (incidence of catheter-related complications) of IC-ECG for lower extremity ECC were evaluated. RESULTS: The matching rate between IC-ECG and chest X-ray was 95.0%. When the catheter tip was optimally positioned, the QRS amplitude of the IC-ECG was 0.85 ± 0.56 mv higher than that of the surface electrocardiogram. The overall incidence of catheter-related complications was 10.6%. The actual ECC insertion length was associated with a noticeably increased risk of catheter-related complications. CONCLUSIONS: This study suggests that IC-ECG is an effective and safe method by observing the dynamic changes in both QRS complexes and P wave to locate the tip of lower extremity ECC in preterm infants. Our findings would facilitate the application of IC-ECG for ECC localization.

Decomposing the change in the cognitive function gap between older men and women over time in China: The Chinese Longitudinal Healthy Longevity Survey.

Background: This study explored how modifiable social determinants of cognitive function can influence these gender gaps. Methods: We utilized six waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), including 56,127 individuals aged 65+. The Kitagawa-Oaxaca-Blinder decomposition approach was used for the analysis. Results: Older women consistently had lower average levels of cognitive function than men in each period, but the gap is narrowing. From 2002 to 2018, the gender gap in cognitive function decreased by 1.45 (95% confidence interval (CI) = -1.843, -1.097) points. The coefficients for the endowment effects decreased from 0.387 (95% CI = -0.563, -0.211) to 1.789 (95% CI = -2.471, -1.107) from 2005 to 2018. Lifestyle changes, social participation, and physical health factors significantly contributed to explaining the changes in gender gaps in cognitive function. Conclusions: Among these contributing factors, lifestyle, social participation, and physical health have emerged as pivotal elements in reducing the gender gap in cognitive function. Targeted interventions for these variables are essential among older women to narrow the cognitive gender gaps effectively.

Cholesterol metabolism in T-cell aging: Accomplices or victims.

Aging has a significant impact on the function and metabolism of T cells. Cholesterol, the most important sterol in mammals, is known as the "gold of the body" because it maintains membrane fluidity, rigidity, and signal transduction while also serving as a precursor of oxysterols, bile acids, and steroid hormones. Cholesterol homeostasis is primarily controlled by uptake, biosynthesis, efflux, and regulatory mechanisms. Previous studies have suggested that there are reciprocal interactions between cholesterol metabolism and T lymphocytes. Here, we will summarize the most recent advances in the effects of cholesterol and its derivatives on T-cell aging. We will furthermore discuss interventions that might be used to help older individuals with immune deficiencies or diminishing immune competence.

Patterns of Social Isolation and Low Social Support and Frailty Trajectories Among Chinese Older Adults.

Objectives: This study aims to identify patterns of social isolation and low social support, and discover their associations with frailty trajectories among Chinese older adults. Methods: The paper used five waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS, 2005-2018). The latent class analysis, multi-trajectory modeling, and the multinomial logistic regression approaches were used to perform the analysis. Results: The paper identified five types of social isolation and low social support, and three typical frailty trajectories. Patterns of social isolation and low social support were associated with frailty trajectories among older adults. Conclusions: Distinct patterns of social isolation and low social support were significantly correlated with frailty trajectories. To improve frailty trajectories among older adults, interventions such as Healthy China 2030 should prioritize addressing the interplay between social isolation and low social support.

Highly efficient overexpression and purification of multisubunit tethering complexes in Saccharomyces cerevisiae.

Vesicle trafficking is a fundamental cellular process that ensures proper material exchange between organelles in eukaryotic cells, and multisubunit tethering complexes (MTCs) are essential in this process. The heterohexameric homotypic fusion and protein sorting (HOPS) complex, which functions in the endolysosomal pathway, is a member of MTCs. Despite its critical role, the complex composition and low-expression level of HOPS have made its expression and purification extremely challenging. In this study, we present a highly efficient strategy for overexpressing and purifying HOPS from Saccharomyces cerevisiae. We achieved HOPS overexpression by integrating a strong promoter TEF1 before each subunit using the gRNA-tRNA array for CRISPR-Cas9 (GTR-CRISPR) system. The HOPS complex was subsequently purified using Staphylococcus aureus protein A (ProtA) affinity purification and size-exclusion chromatography, resulting in high purity and homogeneity. We obtained two-fold more HOPS using this method than that obtained using the commonly used GAL1 promoter-controlled HOPS overexpression. Negative staining electron microscopy analysis confirmed the correct assembly of HOPS. Notably, we also successfully purified two other MTCs, class C core vacuole/endosome tethering (CORVET) and Golgi-associated retrograde protein (GARP) using this approach. Our findings facilitate further in vitro biochemical characterization and functional studies of MTCs and provide a useful guide for the preparation of other heterogenic multisubunit complexes.

Dual trajectories of depression and social participation among Chinese older adults.

OBJECTIVES: This study aimed to investigate the dual trajectories of social participation (SP) and depression among older adults, and explore common factors that may influence both trajectories. METHODS: The study utilized data from four waves of the China Health and Retirement Longitudinal Study (CHARLS, 2011 to 2018). The dual-trajectory model was employed to estimate the dual trajectories of SP and depression. RESULTS: This study identified two SP and three depression trajectories. The results revealed that the reciprocal relationship between SP and depression trajectories is confirmed in all sub-groups of the dual trajectories. Our study identified six distinct sub-groups of individuals based on their SP and depression trajectories and some commen risk factors of SP and depression trajectories. CONCLUSIONS: Related intervention policies should consider the dual trajectories of SP and depression and focus on subgroups with high vulnerability, such as high depression but low SP. Additionally, attention should be given to addressing the common risk factors that underlie these trajectories.

Does long-term care insurance reduce the disability among middle-aged and older adults? Evidence from China.

This study aimed to examine whether the implementation of Long-Term Care Insurance (LTCI) policy could reduce the disability among middle-aged and older adults in China, and to test the heterogeneity of the effects. Data came from four waves of the China Health and Retirement Longitudinal Study (CHARLS, 2011 to 2018). The Difference-In-Differences (DID) method and the panel data fixed effect model were used to estimate the effect of implementation of LTCI policy on disability among individuals aged 45 years and above. The LTCI policy had a positive impact on reducing disability among middle-aged and older people. Females, younger adults, city dwellers, and individuals living alone benefited the most from LTCI policy. The results provided empirical evidence for the implementation of LTCI policy in China and other similar countries as China. The implementation of LTCI policy should also pay more attention to inequity of the effects on reducing disability among different demographic groups.

Lipidomics Analysis Explores the Mechanism of Renal Injury in Rat Induced by 3-MCPD.

3-monochloropropane-1,2-diol (3-MCPD) is a food-process toxic substance, and its main target organ is the kidney. The present study examined and characterized the nephrotoxicity and the lipidomic mechanisms in a model of kidney injury in Sprague Dawley (SD) rats treated with high (45 mg/kg) and low (30 mg/kg) doses of 3-MCPD. The results showed that the ingestion of 3-MCPD led to a dose-dependent increase in serum creatinine and urea nitrogen levels and histological renal impairment. The oxidative stress indicators (MDA, GSH, T-AOC) in the rat kidney altered in a dose-dependent manner in 3-MCPD groups. The lipidomics analysis revealed that 3-MCPD caused kidney injury by interfering with glycerophospholipid metabolism and sphingolipid metabolism. In addition, 38 lipids were screened as potential biomarkers. This study not only revealed the mechanism of 3-MCPD renal toxicity from the perspective of lipidomics but also provided a new approach to the study of 3-MCPD nephrotoxicity.

Acyl-coenzyme A binding protein MoAcb1 regulates conidiation and pathogenicity in Magnaporthe oryzae.

Magnaporthe oryzae is a filamentous fungus that causes rice blast. Rice blast seriously threatens the safety of food production. The normal synthesis and metabolism of fatty acids are extremely important for eukaryotes, and acyl-CoA is involved in fatty acid metabolism. Acyl-CoA binding (ACB) proteins specifically bind both medium-chain and long-chain acyl-CoA esters. However, the role of the Acb protein in plant-pathogenic fungi has not yet been investigated. Here, we identified MoAcb1, a homolog of the Acb protein in Saccharomyces cerevisiae. Disruption of MoACB1 causes delayed hyphal growth, significant reduction in conidial production and delayed appressorium development, glycogen availability, and reduced pathogenicity. Using immunoblotting and chemical drug sensitivity analysis, MoAcb1 was found to be involved in endoplasmic reticulum autophagy (ER-phagy). In conclusion, our results suggested that MoAcb1 is involved in conidia germination, appressorium development, pathogenicity and autophagy processes in M. oryzae.

School connectedness and psychological resilience as mediators in the relationship between childhood abuse and suicidal ideation among Chinese adolescents.

Background: Suicide among adolescents is a huge public health concern around the world. Although childhood abuse has been established as a substantial risk factor for suicide behaviours, potential mediators in this relationship remain unclear.Objective: This study aimed to examine the mediating roles of school connectedness and psychological resilience in the association between childhood abuse and suicidal ideation among Chinese high school students.Methods: The sample involved 1607 adolescents from four high schools in Central China. Structural equation modelling (SEM) was conducted to investigate the mediation effects of school connectedness and psychological resilience on the relationship between childhood abuse and suicidal ideation.Results: The prevalence of suicidal ideation during the past week was 21.9%. Childhood abuse was positively related to the development of suicidal ideation directly and indirectly through school connectedness and psychological resilience. School connectedness and psychological resilience were also partial mediators of all three types of childhood abuse (emotional abuse, physical abuse and sexual abuse) when the types were examined separately.Conclusions: Suicidal ideation was widespread among Chinese high school students. Psychological resilience and school connectedness could attenuate the detrimental impact of childhood abuse on suicidal ideation. Findings underscore the improvement of psychological resilience and the connection to the school would be beneficial to suicide prevention among Chinese adolescents with childhood abuse.

Adolescent suicide is a major public health concern worldwide.Childhood abuse exerts a negative effect on suicide behaviours.School connectedness and psychological resilience mediated the relationship between childhood abuse and suicidal ideation.

Age and cohort trends in disability among Chinese older adults.

Objective: This study aimed to examine age and cohort trends in disability among Chinese older adults and explore the disablement process factors that may explain the cohort trends in disability. Methods: This study used data from five waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A hierarchical logistic growth model was used to analyze the A-P-C effects and the contributors of cohort trends. Results: ADL, IADL, and FL among Chinese older adults showed increasing age and cohort trends. FL was more likely to result in IADL disability than ADL disability. Among the disablement process factors, gender, residence, education, health behavior, disease, and family income contributed to most of the cohort trends in disability. Conclusions: As older adults face increasing disability trends, it is necessary to distinguish age and cohort trends and develop more effective interventions according to relative contributors to prevent disability among them.

Effects of trunk neuromuscular electrical stimulation on the motor circuits of able-bodied individuals.

Upper- and lower-limb neuromuscular electrical stimulation (NMES) is known to modulate the excitability of the neural motor circuits. However, it remains unclear whether short-duration trunk muscle NMES could achieve similar neuromodulation effects. We assessed motor evoked potentials (MEPs) elicited through transcranial magnetic stimulation of the primary motor cortex representation of the trunk extensor muscles to evaluate corticospinal excitability. Moreover, cervicomedullary motor evoked potentials (CMEPs) were assessed through cervicomedullary junction magnetic stimulation to evaluate subcortical excitability. Twelve able-bodied individuals participated in the MEP study, and another twelve in the CMEP study. During the interventions, NMES was applied bilaterally to activate the erector spinae muscle and produce intermittent contractions (20 s ON/20 s OFF) for a total of 20 min while participants remained seated. Assessments were performed: (i) before; (ii) during (in brief periods when NMES was OFF); and (iii) immediately after the interventions to compare MEP or CMEP excitability. Our results showed that MEP responses were not affected by trunk NMES, while CMEP responses were facilitated for approximately 8 min during the intervention, and returned to baseline before the end of the 20 min stimulating period. Our findings therefore suggest that short-duration NMES of the trunk extensor muscles likely does not affect the corticospinal excitability, but it has a potential to facilitate subcortical neural circuits immediately after starting the intervention. These findings indicate that short-duration application of NEMS may be helpful in rehabilitation to enhance neuromodulation of the trunk subcortical neural motor circuits.

Characterization of a Galactose Oxidase from Fusarium odoratissimum and Its Application in the Modification of Agarose.

A galactose oxidase gene, gao-5f, was cloned from Fusarium odoratissimum and successfully expressed in E. coli. The galactose oxidase GAO-5F belongs to the AA5 family and consists of 681 amino acids, with an estimated molecular weight of 72 kDa. GAO-5F exhibited maximum activity at 40 °C and pH 7.0 and showed no change in activity after 24 h incubation at 30 °C. Moreover, GAO-5F exhibited 40% of its maximum activity after 24 h incubation at 50 °C and 60% after 40 h incubation at pH 7.0. The measured thermostability of GAO-5F is superior to galactose oxidase's reported thermostability. The enzyme exhibited strict substrate specificity toward D-galactose and oligosaccharides/polysaccharides containing D-galactose. Further analysis demonstrated that GAO-5F specifically oxidized agarose to a polyaldehyde-based polymer, which could be used as a polyaldehyde to crosslink with gelatin to form edible packaging films. To our knowledge, this is the first report about the modification of agarose by galactose oxidase, and this result has laid a foundation for the further development of edible membranes using agarose.

Age and cohort trends of the impact of socioeconomic status on dietary diversity among Chinese older adults from the perspective of urban-rural differences: A prospective cohort study based on CLHLS 2002-2018.

The association between socioeconomic status (SES) and dietary diversity score (DDS) has been widely discussed, but little is known about the age and cohort effects on DDS and how the SES effect on DDS varies with age and across successive cohorts among urban and rural older adults in China. Thus, this study aimed to examine the temporal change in DDS among Chinese older adults and SES heterogeneities in such change from the perspective of urban-rural differentiation. Data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) between 2002 and 2018 were used, and a total of 13,728 participants aged between 65 and 105 years were included in this study. A total of eight food groups were used to assess DDS, while education, family income, and perceived income status were used to assess SES. A linear mixed model was used to estimate the age and cohort effects on DDS and their urban-rural and SES disparities. The results show that higher SES, including more education, family income, and perceived income status, was associated with higher DDS (for urban older adults, ß = 0.1645, p = 0.0003, ß = 0.2638, p < 0.0001, ß = 0.2917, p < 0.0001, respectively; for rural older adults, ß = 0.0932, p = 0.0080, ß = 0.4063, p < 0.0001, ß = 0.2921, p < 0.0001, respectively). The DDS of older adults increased with age and across successive cohorts in both urban and rural China. Moreover, we found the three-way interaction effect of SES, age, and cohort was statistically significant in both urban and rural China. Thus, living in an urban area and having higher SES are associated with higher DDS, but these associations change with age and across successive cohorts. The dietary health of earlier cohorts and rural oldest-old in China deserves more attention.

The Amino Acid Permease MoGap1 Regulates TOR Activity and Autophagy in Magnaporthe oryzae.

Rice is an important food crop all over the world. It can be infected by the rice blast fungus Magnaporthe oryzae, which results in a significant reduction in rice yield. The infection mechanism of M. oryzae has been an academic focus for a long time. It has been found that G protein, AMPK, cAMP-PKA, and MPS1-MAPK pathways play different roles in the infection process. Recently, the function of TOR signaling in regulating cell growth and autophagy by receiving nutritional signals generated by plant pathogenic fungi has been demonstrated, but its regulatory mechanism in response to the nutritional signals remains unclear. In this study, a yeast amino acid permease homologue MoGap1 was identified and a knockout mutant of MoGap1 was successfully obtained. Through a phenotypic analysis, a stress analysis, autophagy flux detection, and a TOR activity analysis, we found that the deletion of MoGap1 led to a sporulation reduction as well as increased sensitivity to cell wall stress and carbon source stress in M. oryzae. The ΔMogap1 mutant showed high sensitivity to the TOR inhibitor rapamycin. A Western blot analysis further confirmed that the TOR activity significantly decreased, which improved the level of autophagy. The results suggested that MoGap1, as an upstream regulator of TOR signaling, regulated autophagy and responded to adversities such as cell wall stress by regulating the TOR activity.

Effective corticospinal excitability neuromodulation elicited by short-duration concurrent and synchronized associative cortical and neuromuscular stimulations.

Optimal parameters of combined repetitive associative transcranial magnetic stimulation (rTMS) and neuromuscular electrical stimulation (NMES) for neuromodulation of central nervous system (CNS) excitability are not well understood. We examined corticospinal excitability after short-duration concurrent and synchronized associative stimulation applied using primary motor cortex rTMS and upper-limb NMES. Intermittent theta burst stimulation (iTBS) was delivered with burst at 50 Hz and repeated at 5 Hz over the course of 192 s as an established cortical facilitation rTMS protocol. NMES was applied to activate the extensor carpi radialis muscle over the same 192 s duration. Four interventions were compared: (1) iTBS with concurrent and synchronized 50 Hz NMES; (2) iTBS with concurrent and synchronized 5 Hz NMES; (3) iTBS with concurrent and asynchronized 41 Hz NMES; (4) iTBS with 5 s delayed and synchronized 50 Hz NMES. Single-pulse motor evoked potential (MEP) responses elicited by transcranial magnetic stimulation of the primary motor cortex and maximum motor responses (Mmax) elicited by radial nerve stimulation were compared before and for 30 min after each intervention. Our results showed that corticospinal excitability (MEP/Mmax) was only facilitated after the iTBS and concurrent 50 Hz NMES intervention, but the responses returned to baseline within 10 min of completing the intervention. This result demonstrates that short-duration concurrent and synchronized stimulation could be applied to effectively neuromodulate corticospinal excitability. Therefore, repetitive synchronized associative stimulation of the primary motor cortical networks and sensorimotor peripheral circuits may be enhanced using synchronized 50 Hz frequency of activation during concurrent stimulation.

Acoustics-Controlled Microdroplet and Microbubble Fusion and Its Application in the Synthesis of Hydrogel Microspheres.

Droplet fusion technology is a key technology for many droplet-based biochemical medical applications. By integrating a symmetrical flow channel structure, we demonstrate an acoustics-controlled fusion method of microdroplets using surface acoustic waves. Different kinds of microdroplets can be staggered and ordered in the symmetrical flow channel, proving the good arrangement effect of the microfluidic chip. This method can realize not only the effective fusion of microbubbles but also the effective fusion of microdroplets of different sizes without any modification. Further, we investigate the influence of the input frequency and peak-to-peak value of the driving voltage on microdroplets fusion, giving the effective fusion parameter conditions of microdroplets. Finally, this method is successfully used in the preparation of hydrogel microspheres, offering a new platform for the synthesis of hydrogel microspheres.

Duration of immunogenicity of high-dose and prolonged-schedule hepatitis B vaccine among patients with chronic kidney disease: A one year follow-up study in China.

BACKGROUND: Patients with chronic kidney disease (CKD) have immunological defects that result in reduced production and faster decay of anti-HBs after hepatitis B vaccination. We assessed the duration of the immunogenicity after four-standard-dose and four-triple-dose regimens among patients with CKD. METHODS: A randomized controlled trial was conducted between May 2019 and February 2020. Patients were randomly allocated to receive three or four doses of 20 µg    , or four doses of 60 µg   of hepatitis B vaccine. Immunogenicity was assessed for 18 months till February 2021. RESULTS: Between months 7 and 18, the seroconversion rate decreased from 81.7% (58/71) to 64.3% (36/56) in IM20 × 3 group, from 93.0% (66/71) to 77.4% (41/53) in IM20 × 4 group, and from 93.2% (68/73) to 90.7% (49/54) in IM60 × 4 group. Seroconversion was higher in IM60 × 4 group than in IM20 × 3 group at month 18 (P < 0.05). In multivariate analysis, CKD patients without immune suppression or hormone therapy or patients with IM60 × 4 were more likely to have durable immunogenicity at month 18. CONCLUSIONS: Patients receiving four-triple-dose regimen of hepatitis B vaccine showed improved duration of immunogenicity at the one-year follow-up. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT03962881).