Tic12, a 12-kDa essential component of the translocon at the inner envelope membrane of chloroplasts in Arabidopsis.

The complexes translocon at the outer envelope membrane of chloroplasts and translocon at the inner envelope membrane of chloroplasts (TIC) mediate preprotein translocation across the chloroplast outer and inner envelope membranes, respectively. Tic20, Tic56, Tic100, and Tic214 form a stable one-megadalton TIC whose function is essential for Arabidopsis thaliana and Chlamydomonas reinhardtii. Tic20 plays a central role in preprotein translocation by forming a protein-conducting channel. Tic56, Tic100, and Tic214 are also indispensable for TIC function, but whether other components are required for this process remain unclear. Here, we demonstrate that a 12-kDa protein named Tic12 is part of the TIC in A. thaliana and participates in preprotein translocation across the inner envelope membrane. Tic12 was tightly associated with the TIC but disassociated under high-salt conditions in combination with Triton X-100. Site-specific UV crosslinking experiments revealed that Tic12 and Tic20 directly interact with the transit peptide of a translocating preprotein. The tic12 null mutants are albino and seedling lethal, similar to the other tic null mutants. Tic12 and Tic20 were also involved in preprotein translocation in (Pisum sativum) pea chloroplasts. Thus, Tic12 is an essential constituent that forms the functional core together with Tic20 in the one-megadalton TIC.

Highly Efficient Acidic Electrosynthesis of Hydrogen Peroxide at Industrial-Level Current Densities Promoted by Alkali Metal Cations.

Acidic H2O2 synthesis through electrocatalytic 2e- oxygen reduction presents a sustainable alternative to the energy-intensive anthraquinone oxidation technology. Nevertheless, acidic H2O2 electrosynthesis suffers from low H2O2 Faradaic efficiencies primarily due to the competing reactions of 4e- oxygen reduction to H2O and hydrogen evolution in environments with high H+ concentrations. Here, we demonstrate the significant effect of alkali metal cations, acting as competing ions with H+, in promoting acidic H2O2 electrosynthesis at industrial-level currents, resulting in an effective current densities of 50-421 mA cm-2 with 84-100 % Faradaic efficiency and a production rate of 856-7842 µmol cm-2 h-1 that far exceeds the performance observed in pure acidic electrolytes or low-current electrolysis. Finite-element simulations indicate that high interfacial pH near the electrode surface formed at high currents is crucial for activating the promotional effect of K+. In situ attenuated total reflection Fourier transform infrared spectroscopy and ab initio molecular dynamics simulations reveal the central role of alkali metal cations in stabilizing the key *OOH intermediate to suppress 4e- oxygen reduction through interacting with coordinated H2O.

A systematic dissection in oilseed rape provides insights into the genetic architecture and molecular mechanism of yield heterosis.

Heterosis refers to the better performance of cross progeny compared with inbred parents, and its utilization contributes greatly to agricultural production. Several hypotheses have been proposed to explain heterosis mainly including dominance, over-dominance (or pseudo-overdominance) and epistasis. However, systematic dissection and verification of these hypotheses are rarely documented. Here, comparison of heterosis level across different traits showed that the strong heterosis of composite traits (such as yield) could be attributed to the multiplicative effects of moderate heterosis of component traits, whether at the genome or locus level. Yield heterosis was regulated by a complex trait-QTL network that was characterized by obvious centre-periphery structure, hub QTL, complex up/downstream and positive/negative feedback relationships. More importantly, we showed that better-parent heterosis on yield could be produced in a cross of two near-isogenic lines by the pyramiding and complementation of two major heterotic QTL showing partial-dominance on yield components. The causal gene (BnaA9.CYP78A9) of QC14 was identified, and its heterotic effect results from the heterozygous status of a CACTA-like transposable element in its upstream regulatory region, which led to partial dominance at expression and auxin levels, thus resulting in non-additive expression of downstream responsive genes involved in cell cycle and proliferation, eventually leading to the heterosis of cell number. Taken together, the results at the phenotypic, genetic and molecular levels were highly consistent, which demonstrated that the pyramiding effect of heterotic QTL and the multiplicative effect of individual component traits could well explain substantial parts of yield heterosis in oilseed rape. These results provide in-depth insights into the genetic architecture and molecular mechanism of yield heterosis.

Effectiveness of continuity of care in reducing depression symptoms in elderly: A systematic review and meta-analysis.

BACKGROUND: Depression affects 10%-20% of older adults worldwide. The course of late-life depression (LLD) is often chronic, with a poor long-term prognosis. Lower treatment adherence, stigma, and suicide risk lead to significant challenges in the continuity of care (COC) for patients with LLD. Elderly patients with chronic diseases can benefit from COC. As a common chronic disease of the elderly, whether depression can also benefit from COC has not been systematically reviewed. METHODS: Systematic literature search in Embase, Cochrane Library, Web of Science, Ovid, PubMed and Medline. Randomized Controlled Trials (RCTs) on the intervention effects of COC and LLD, published on 12 April 2022, were selected. Two independent researchers made research choices based on consensus. An RCT with COC as an intervention measure for the elderly with depression 60 years old was the inclusion criteria. RESULTS: A total of 10 RCTs involving 1557 participants were identified in this study. The findings showed that: (1) COC significantly reduced depressive symptoms compared to usual care (standardized mean difference [SMD] = -0.47, 95% confidence interval: -0.63 to -0.31), with the best improvement at 3- to 6-month follow-up; (2) The reduction in depressive symptoms was more pronounced for patients with comorbid chronic conditions with LLD (SMD = -0.93, 95% CI: -1.18 to -0.68); (3) COC was more effective than other regions for LLD in Europe and the Americas (SMD = -0.84, 95% CI: -1.07 to -0.61); and (4) COC had a positive impact on the quality of life of patients with LLD (SMD = 0.21, 95% CI: 0.02-0.40). LIMITATIONS: The included studies included several multi-component interventions with widely varying methods. Therefore, it was almost impossible to analyze which of these interventions had an impact on the assessed outcomes. CONCLUSIONS: This meta-analysis shows that COC can significantly reduce depressive symptoms and improve quality of life in patients with LLD. However, when treating and caring for patients with LLD, health care providers should also pay attention to timely adjustments of intervention plans according to follow-up, synergistic interventions for multiple co-morbidities, and actively learning from advanced COC programs at home and abroad to improve the quality and effectiveness of services.

Social support and coping style of Tongqi in China: A cross-sectional study.

Tongqi (gays' wives) in China were under tremendous distress and social pressure due to their special identities and were not clearly known. A sample of 179 Chinese Tongqi were recruited through online social media groups in 2017-2018. Their hidden lives, social support, and coping styles were analyzed. The results showed that the majority of Tongqi concealed their identities, had negative responses to cope with their tremendous distress, and did not have sufficient social support. Their social support was mainly from family members. Hidden identities obstructed Tongqi's access to extrafamilial social support that could alleviate their distress. Tongqi need more social support and protection.

Enhanced Perfluorooctanoic Acid Degradation by Electrochemical Activation of Sulfate Solution on B/N Codoped Diamond.

Electrochemical oxidation based on SO4•- and •OH generated from sulfate electrolyte is a cost-effective method for degradation of persistent organic pollutants (POPs). However, sulfate activation remains a great challenge due to lack of active and robust electrodes. Herein, a B/N codoped diamond (BND) electrode is designed for electrochemical degradation of POPs via sulfate activation. It is efficient and stable for perfluorooctanoic acid (PFOA) oxidation with first-order kinetic constants of 2.4 h-1 and total organic carbon removal efficiency of 77.4% (3 h) at relatively low current density of 4 mA cm-2. The good activity of BND mainly originates from a B and N codoping effect. The PFOA oxidation rate at sulfate electrolyte is significantly enhanced (2.3-3.4 times) compared with those at nitrate and perchlorate electrolytes. At sulfate, PFOA oxidation rate decreases slightly in the presence of •OH quencher while it declines significantly with SO4•- and •OH quenchers, indicate both SO4•- and â€¢OH contribute to PFOA oxidation but SO4•- contribution is more significant. On the basis of intermediates analysis, a proposed mechanism for PFOA degradation is that PFOA is oxidized to shorter chain perfluorocarboxylic acids gradually by SO4•- and •OH until it is mineralized.

Spin-dependent quantum interference in Aharonov-Bohm ring embedded with two double-quantum-dot molecules.

The spin polarized transport properties through an Aharonov-Bohm ring embedded with a double quantum dot-molecule in each arm with Rashba spin-orbit (RSO) interaction is theoretically studied in the framework of the equation of motion of Green's function. Based on molecular state representation, the anti-resonance phenomenon in the conductance spectrum is readily explained. We found that the position of antiresonant peaks in conductance spectrum is determined by the interdot coupling strengths. Moreover, the magnitude of conductance of each spin component can be manipulated by the Rashba spin orbit interaction strength. Especially only one spin component electron can be allowed to transport through this structure by modulating the strength of RSO interaction properly.

Electronic transport through a benzene-shaped quantum dots system.

Based on the nonequilibrium Green function method, quantum transport through a benzene-shaped quantum dots system is studied. It is shown that the conductance spectrum is sensitive to the arrangement of energy levels of dots. When the energy levels of dots are mismatched, the conductance shows apparent asymmetric structure and striking novel conductance dips appear due to the interference between two distinct paths. The differential conductance as a function of magnetic flux always exhibits 2pi period. An overall suppression of differential conductance emerges for the condition that the levels of dots are all aligned and phi = (2n + 1)pi (n is an integer). In addition, the influence of temperature on the differential conductance is presented.

Enhanced CO2 reduction with hydrophobic cationic-ionomer layer-modified zero-gap MEA in acidic electrolyte.

A hydrophobic cationic-ionomer layer of quaternary ammonium poly(N-methyl-piperidine-co-p-terphenyl) and PTFE is presented to enhance the CO2 electroreduction in a zero-gap membrane electrode assembly (MEA) electrolyzer under acidic and low alkali ion concentration conditions. The modified MEA achieved a maximum CO faradaic efficiency of 95.6% at 100 mA cm-2.

Effectiveness of Telecare Interventions on Depression Symptoms Among Older Adults: Systematic Review and Meta-Analysis.

BACKGROUND: Depression is the most common psychiatric disorder among older adults. Despite the effectiveness of pharmacological and psychological therapies, many patients with late-life depression (LLD) are unable to access timely treatment. Telecare has been shown to be effective in addressing patients' psychosocial issues, while its effectiveness in serving patients with LLD remains unclear. OBJECTIVE: This study aimed to evaluate the effectiveness of telecare in reducing depression and anxiety symptoms and improving quality of life (QoL) in patients with LLD. METHODS: Databases including the Cochrane Library, Web of Science, PubMed, Embase, and EBSCO were searched for randomized controlled trials (RCTs) evaluating the effectiveness of telecare for LLD from database establishment to December 28, 2022. RESULTS: A total of 12 RCTs involving 1663 participants were identified in this study. The meta-analysis showed that (1) telecare significantly reduced depressive symptoms in patients with LLD compared to those in usual care (UC; standardized mean difference [SMD]=-0.46, 95% CI -0.53 to -0.38; P<.001), with the best improvement observed within 3 months of intervention (SMD=-0.72, 95% CI -1.16 to -0.28; P<.001); (2) other scales appeared more effective than the Patient Health Questionnaire-9 for LLD in telecare interventions (SMD=-0.65, 95% CI -0.96 to -0.35; P<.001); (3) telecare was more effective than telephone-based interventions for remote monitoring of LLD (SMD=-1.13, 95% CI -1.51 to -0.76; P<.001); (4) the reduction of depressive symptoms was more pronounced in patients with LLD with chronic conditions (SMD=-0.67, 95% CI -0.89 to -0.44; P<.001); (5) telecare was more effective for LLD in Europe and the Americas than in other regions (SMD=-0.73, 95% CI -0.99 to -0.47; P<.001); (6) telecare significantly reduced anxiety symptoms in patients with LLD (SMD=-0.53, 95% CI -0.73 to -0.33; P=.02); and (7) there was no significant improvement in the psychological components of QoL in patients with LLD compared to those receiving UC (SMD=0.30, 95% CI 0.18-0.43; P=.80). CONCLUSIONS: Telecare is a promising modality of care for treatment, which can alleviate depression and anxiety symptoms in patients with LLD. Continued in-depth research into the effectiveness of telecare in treating depression could better identify where older patients would benefit from this intervention.

Understanding the relationship between smartphone distraction, social withdrawal, digital stress, and depression among college students: A cross-sectional study in Wuhan, China.

Background: Smartphone distraction considerably affects the depression level of college students. These two variables are highly associated with social withdrawal and digital distress. However, the underlying mechanisms of how social withdrawal and digital stress were involved in the relationship between smartphone distraction and depression remain unclear. Methods: A cross-sectional survey was conducted in seven colleges of Wuhan, Hubei Province, from September to November 2021. Participants were selected using convenience sampling. Smartphone distraction, social withdrawal, digital stress, and depression level were assessed using the Smartphone Distraction Scale (SDS), 25-item Hikikomori Questionnaire (HQ-25), Multidimensional Digital Stress Scale (DSS), and the Patient Health Questionnaire-9 (PHQ-9), respectively. All scales demonstrated good reliability in this study, the reliability of each scale was 0.920, 0.884, 0.959, and 0.942. Results: The final analysis included 1184 students (692 males and 492 females), aged between 17 and 37 years. Participants were from various academic disciplines, including medical and non-medical. The findings revealed that smartphone distraction had a significant direct effect on depression (c = 0.073, 95 % CI: 0.037 to 0.108, p < 0.001) and three significant indirect mediation effects: (1) social withdrawal (B = 0.083, 95 % CI: 0.066 to 0.101, p < 0.001), accounting for 27.76 % of the total effect; (2) digital stress (B = 0.109, 95 % CI: 0.088 to 0.132, p < 0.001), accounting for 36.45 % of the total effect; and (3) the chain mediating roles of social withdrawal and digital stress (B = 0.034, 95 % CI: 0.026 to 0.043, p < 0.001), accounting for 11.37 % of the total effect. The total mediating effect was 75.59 %. Limitations: This study is based on cross-sectional data, which limits the causality inference. Conclusions: These findings suggest that educational institutions should identify college students with excessive smartphone use early and provide timely interventions to minimize negative outcomes. It is also significant to reduce the risk of social withdrawal and digital stress to maintain the physical and mental health development of college students.

Efficient Recovery of Complete Gut Viral Genomes by Combined Short- and Long-Read Sequencing.

Current metagenome assembled human gut phage catalogs contained mostly fragmented genomes. Here, comprehensive gut virome detection procedure is developed involving virus-like particle (VLP) enrichment from ≈500 g feces and combined sequencing of short- and long-read. Applied to 135 samples, a Chinese Gut Virome Catalog (CHGV) is assembled consisting of 21,499 non-redundant viral operational taxonomic units (vOTUs) that are significantly longer than those obtained by short-read sequencing and contained ≈35% (7675) complete genomes, which is ≈nine times more than those in the Gut Virome Database (GVD, ≈4%, 1,443). Interestingly, the majority (≈60%, 13,356) of the CHGV vOTUs are obtained by either long-read or hybrid assemblies, with little overlap with those assembled from only the short-read data. With this dataset, vast diversity of the gut virome is elucidated, including the identification of 32% (6,962) novel vOTUs compare to public gut virome databases, dozens of phages that are more prevalent than the crAssphages and/or Gubaphages, and several viral clades that are more diverse than the two. Finally, the functional capacities are also characterized of the CHGV encoded proteins and constructed a viral-host interaction network to facilitate future research and applications.

Microstructure, Mechanical Properties, and Corrosion Resistance of Ag-Cu Alloys with La2O3 Fabricated by Selective Laser Melting.

Ag and its alloys, when prepared by a selective laser melting (SLM) process, have a low density and poor overall performance due to their high reflectivity when the most commonly used laser (λ = 1060 nm) is used, and they have exorbitant thermal conductivity. These characteristics lead to the insufficient melting of the powders and severely limit the applications of additive manufactured silver alloys. To improve the absorption of the laser, as well as for better mechanical properties and higher resistance to sulfidation, Ag-Cu alloys with different La2O3 contents were prepared in this work using the SLM process, via the mechanical mixing of La2O3 nanoparticles with Ag-Cu alloy powders. A series of analyses and tests were conducted to study the effects of La2O3 in Ag-Cu alloys on their density, microstructure, mechanical properties, and corrosion resistance. The results revealed that the addition of La2O3 particles to Ag-Cu alloy powders improved the laser absorptivity and reduced defects during the SLM process, leading to a significant rise from 7.76 g/cm3 to 9.16 g/cm3 in the density of the Ag-Cu alloys. The phase composition of the Ag-Cu alloys prepared by SLM was Silver-3C. La2O3 addition had no influence on the phase composition, but refined the grains of the Ag-Cu alloys by inhibiting the growth of columnar grains during the SLM process. No remarkable preferred orientation existed in all the samples prepared with or without La2O3. An upwards trend was achieved in the hardness of the Ag-Cu alloy by increasing the contents of La2O3 from 0 to 1.2%, and the average hardness was enhanced significantly, from 0.97 GPa to 2.88 GPa when the alloy contained 1.2% La2O3 due to the reduced pore defects and the refined grains resulting from the effects of the La2O3. EIS and PD tests of the samples in 1% Na2S solution proved that La2O3 addition improved the corrosion resistance of the Ag-Cu alloys practically and efficaciously. The samples containing La2O3 exhibited higher impedance values and lower corrosion current densities.

Effects of Tai Chi on depression of middle-aged and older adults: an updated systematic review and meta-analysis.

AIM: The objective of this study was to evaluate the efficacy of Tai Chi, a mind-body movement therapy originating from China, on depression in middle-aged and older adults. METHODS: A systematic search was conducted in seven databases (Embase, Cochrane, Medline, Wanfang, SinoMed, Weipu date, CNKI) for Randomized Controlled Trials (RCTs) published until Apr 16, 2023. The quality assessment, heterogeneity analysis, subgroup analysis, and sensitivity analysis of 12 RCTs selected from the literature were performed. Meta-analyses were conducted using RevMan 5.4 software. RESULTS: The study included 12 trials comprising 731 participants that met the inclusion criteria. The findings revealed that Tai Chi significantly improved depression in middle-aged and older adults [SMD = -1.21, 95% CI (-1.59, -0.83), I2 = 87.6%, P < 0.001]. Subgroup analysis revealed that the number of exercise weeks within the specified range, the total duration of exercise, and Tai Chi maneuvers had the greatest benefits on depression in middle-aged and elderly people. The results demonstrated that interventions lasting more than 24 weeks were more effective [SMD = -1.66, 95% CI (-2.28, -1.04), P < 0.05] than those lasting only 12 weeks [SMD = -0.73, 95% CI (-1.08, -0.38), P < 0.05]. The effect size was more significant when the total duration of the intervention was more than 2400 min [SMD = -1.31, 95% CI (-1.71, -0.92), P < 0.001], and when the 24-style Tai Chi exercise was selected [SMD = -1.06, 95% CI (-1.37, -0.75), P < 0.001], the difference was also statistically significant. Funnel plots combined with sensitivity analyses, Begg's and Egger's tests indicated no publication bias. CONCLUSION: The study suggests that Tai Chi can be an alternative therapy for reducing depression in middle-aged and older adults. It is recommended to prolong the Tai Chi exercise period to more than 24 weeks, with a total exercise duration of more than 2400 min, and 24-style Tai Chi should be selected to achieve the best therapeutic effect in middle-aged and older adults with depression. It should be noted that there may be lower-quality studies in the RCT literature analyzed, which may limit the general applicability and credibility of the conclusions.

The effect of internet use on depressive symptoms in middle-aged and older adults with functional disability: the mediating role of social isolation.

Objective: The popularization of the internet provides the possibility to improve the depressive symptoms (DS) and social isolation of middle-aged and older adults with functional disability. There was a significant correlation between internet use and DS in middle-aged and older adults with functional disability, but the relationship between internet use, social isolation, and DS remains to be confirmed. Methods: Data were obtained from 7,955 middle-aged and older adults aged 45 years and older from the 2018 China Health and Retirement Longitudinal Study (CHARLS). Multiple linear regression models were used to analyze the association between internet use and DS, and the Sobel test was used to explore mediating models. Results: Results showed that internet use was negatively associated with DS among Chinese middle-aged and older adults. Among them, social needs (B = -0.770, p = 0.041), and information reception (B = -1.067, p = 0.007) were significantly related to DS in middle-aged and older adults. Only information reception (B = -3.161, p = 0.031) was significantly related to DS among middle-aged and older adults with functional disability. Social isolation partially mediated the association between internet use and DS in middle-aged and older adults without functional disability, whereas it was fully mediated in middle-aged and older adults with functional disability. Conclusion: This study indicates that when formulating health policies to promote the mental health of Chinese middle-aged and older adults, the use of the internet should not be overlooked.

Long-Read Sequencing Reveals Extensive DNA Methylations in Human Gut Phagenome Contributed by Prevalently Phage-Encoded Methyltransferases.

DNA methylation plays a crucial role in the survival of bacteriophages (phages), yet the understanding of their genome methylation remains limited. In this study, DNA methylation patterns are analyzed in 8848 metagenome-assembled high-quality phages from 104 fecal samples using single-molecule real-time sequencing. The results demonstrate that 97.60% of gut phages exhibit methylation, with certain factors correlating with methylation densities. Phages with higher methylation densities appear to have potential viability advantages. Strikingly, more than one-third of the phages possess their own DNA methyltransferases (MTases). Increased MTase copies are associated with higher genome methylation densities, specific methylation motifs, and elevated prevalence of certain phage groups. Notably, the majority of these MTases share close homology with those encoded by gut bacteria, suggesting their exchange during phage-bacterium interactions. Furthermore, these MTases can be employed to accurately predict phage-host relationships. Overall, the findings indicate the widespread utilization of DNA methylation by gut DNA phages as an evasion mechanism against host defense systems, with a substantial contribution from phage-encoded MTases.

Enrichment Culture but Not Metagenomic Sequencing Identified a Highly Prevalent Phage Infecting Lactiplantibacillus plantarum in Human Feces.

Lactiplantibacillus plantarum (previously known as Lactobacillus plantarum) is increasingly used as a probiotic to treat human diseases, but its phages in the human gut remain unexplored. Here, we report its first gut phage, Gut-P1, which we systematically screened using metagenomic sequencing, virus-like particle (VLP) sequencing, and enrichment culture from 35 fecal samples. Gut-P1 is virulent, belongs to the Douglaswolinvirus genus, and is highly prevalent in the gut (~11% prevalence); it has a genome of 79,928 bp consisting of 125 protein coding genes and displaying low sequence similarities to public L. plantarum phages. Physiochemical characterization shows that it has a short latent period and adapts to broad ranges of temperatures and pHs. Furthermore, Gut-P1 strongly inhibits the growth of L. plantarum strains at a multiplicity of infection (MOI) of 1e-6. Together, these results indicate that Gut-P1 can greatly impede the application of L. plantarum in humans. Strikingly, Gut-P1 was identified only in the enrichment culture, not in our metagenomic or VLP sequencing data nor in any public human phage databases, indicating the inefficiency of bulk sequencing in recovering low-abundance but highly prevalent phages and pointing to the unexplored hidden diversity of the human gut virome despite recent large-scale sequencing and bioinformatics efforts. IMPORTANCE As Lactiplantibacillus plantarum (previously known as Lactobacillus plantarum) is increasingly used as a probiotic to treat human gut-related diseases, its bacteriophages may pose a certain threat to their further application and should be identified and characterized more often from the human intestine. Here, we isolated and identified the first gut L. plantarum phage that is prevalent in a Chinese population. This phage, Gut-P1, is virulent and can strongly inhibit the growth of multiple L. plantarum strains at low MOIs. Our results also show that bulk sequencing is inefficient at recovering low-abundance but highly prevalent phages such as Gut-P1, suggesting that the hidden diversity of human enteroviruses has not yet been explored. Our results call for innovative approaches to isolate and identify intestinal phages from the human gut and to rethink our current understanding of the enterovirus, particularly its underestimated diversity and overestimated individual specificity.

Multi-function screening of probiotics to improve oral health and evaluating their efficacy in a rat periodontitis model.

The oral cavity is the second most microbially rich region of the human body, and many studies have shown that there is a strong association between microorganisms and oral health. Some pathogenic bacteria produce biofilms and harmful metabolites in the mouth that may cause oral problems such as oral malodor, periodontitis, and dental caries. Altering the oral microbiota by using probiotics may alleviate oral health problems. Thus, using multi-function screening, we aimed to identify probiotics that can significantly improve oral health. The main parameters were the inhibition of pathogenic bacteria growth, inhibition of biofilm formation, reduction in the production of indole, H2S, and NH3 metabolites that cause halitosis, increase in the production of H2O2 to combat harmful bacteria, and co-aggregation with pathogens to prevent their adhesion and colonization in the oral cavity. Tolerance to cholic acid and choline was also assessed. Bifidobacterium animalis ZK-77, Lactobacillus salivarius ZK-88, and Streptococcus salivarius ZK-102 had antibacterial activity and inhibited biofilm production to prevent caries. They also improved the oral malodor parameter, H2S, NH3, and indole production. The selected probiotics (especially L. salivarius ZK-88) alleviated the inflammation in the oral cavity of rats with periodontitis. The analysis of the gingival crevicular fluid microbiome after probiotic intervention showed that B. animalis ZK-77 likely helped to restore the oral microbiota and maintain the oral microecology. Next, we determined the best prebiotics for each candidate probiotic in order to obtain a formulation with improved effects. We then verified that a probiotics/prebiotic combination (B. animalis ZK-77, L. salivarius ZK-88, and fructooligosaccharides) significantly improved halitosis and teeth color in cats. Using whole-genome sequencing and acute toxicity mouse experiments involving the two probiotics, we found that neither probiotic had virulence genes and they had no significant effects on the growth or development of mice, indicating their safety. Taking the results together, B. animalis ZK-77 and L. salivarius ZK-88 can improve oral health, as verified by in vivo and in vitro experiments. This study provides a reference for clinical research and also provides new evidence for the oral health benefits of probiotics.

Real-Time Image Processing Toolbox for All-Optical Closed-Loop Control of Neuronal Activities.

The development of in vivo imaging and optogenetic tools makes it possible to control neural circuit activities in an all-optical, closed-loop manner, but such applications are limited by the lack of software for online analysis of neuronal imaging data. We developed an analysis software ORCA (Online Real-time activity and offline Cross-session Analysis), which performs image registration, neuron segmentation, and activity extraction at over 100 frames per second, fast enough to support real-time detection and readout of neural activity. Our active neuron detection algorithm is purely statistical, achieving a much higher speed than previous methods. We demonstrated closed-loop control of neurons that were identified on the fly, without prior recording or image processing. ORCA also includes a cross-session alignment module that efficiently tracks neurons across multiple sessions. In summary, ORCA is a powerful toolbox for fast imaging data analysis and provides a solution for all-optical closed-loop control of neuronal activity.

Effects of Streptococcus mutans and their metabolites on the wear behavior of dental restorative materials.

The wear behavior of dental restorative materials is highly related to the biolubricating medium in the oral environment. Bacteria, along with their metabolic products, are essential substances in the oral cavity and have not been studied as a potential factor affecting lubrication performance during mastication. In this study, the effects of the Streptococcus mutans bacterial cells and their metabolites were investigated on the wear behavior of resin composites, polymer-infiltrated ceramic networks and zirconium-lithium silicate glass-ceramics. A reciprocating friction test and quantitative analysis of the wear morphology were utilized to determine the coefficient of friction (COF) and wear resistance of the test materials. The results showed that the bacterial metabolite medium significantly reduces the COF and wear rate of the three restorative materials and provide better protection against superficial abrasion. When tested under lactic acid medium, a key acid production in bacterial metabolites, similar wear reduction results were observed in the three materials, which confirmed that lactic acid should be accountable for the excellent lubricating property of bacterial metabolites. Furthermore, the resin composite with lower wettability exhibited a more significant wear reduction than the other two materials when lubricating with a bacterial metabolite medium. These findings provide novel insights into the biological basis of lubrication mechanisms in the oral cavity under high-loading and low-velocity conditions.