Pharmacokinetic assessment of tacrolimus in combination with deoxyschizandrin in rats.

Background: Tacrolimus (Tac) is commonly used for postoperative immunosuppressive therapy in transplant patients. However, problems, for example, low bioavailability and unstable plasma concentration, persist for a long time, Studies have reported that the deoxyschizandrin could effectively improve these problems, but the pharmacokinetic parameters (PKs) of Tac combined with deoxyschizandrin are still unknown. Method: In this study, an UHPLC-MS/MS method has been established for simultaneous quantitation of Tac and deoxyschizandrin. The PKs of Tac influenced by different doses of deoxyschizandrin after single and multiple administrations were analyzed, and the different impact of deoxyschizandrin and Wuzhi capsule on PKs of Tac were compared. Result: The modified UHPLC-MS/MS method could rapid quantification of Tac and deoxyschizandrin within 2 min using bifendatatum as the internal standard (IS). All items were successfully validated. The C max of deoxyschizandrin increased from 148.27 ± 23.20 to 229.13 ± 54.77 ng/mL in rats after multiple administrations for 12 days. After co-administration of 150 mg/mL deoxyschizandrin, Tac had an earlier T max and greater C max and AUC0-t, and the C max and AUC0-t of Tac increased from 14.26 ± 4.73 to 54.48 ± 14.37 ng/mL and from 95.10 ± 32.61 to 315.23 ± 92.22 h/ng/mL, respectively; this relationship was positively proportional to the dosage of deoxyschizandrin. In addition, compared with Wuzhi capsule, the same dose of deoxyschizandrin has a better effective on Tac along with more stable overall PKs. Conclusion: An UHPLC-MS/MS method was established and validated for simultaneous detection of deoxyschizandrin and Tac. Deoxyschizandrin could improve the in vivo exposure level and stability of Tac, besides, this effect is better than Wuzhi capsule in same dose.

Dauresorcinols A and B, two pairs of merosesquiterpenoid enantiomers with new carbon skeletons from Rhododendron dauricum.

Five pairs of new merosesquiterpenoid enantiomers, named dauresorcinols A-E (1-5), were isolated from the leaves of Rhododendron dauricum. Their structures were elucidated by comprehensive spectroscopic data analysis, quantum chemical calculations, Rh2(OCOCF3)4-induced ECD, and single-crystal X-ray diffraction analysis. Dauresorcinols A (1) and B (2) possess two new merosesquiterpene skeletons bearing an unprecedented 2,6,7,10,14-pentamethyl-11-oxatetracyclo[8.8.0.02,7.012,17]octadecane and a caged 15-isohexyl-1,5,15-trimethyl-2,10-dioxatetracyclo[7.4.1.111,14.03,8]pentadecane motif, respectively. Plausible biosynthetic pathways of 1-5 are proposed involving key oxa-electrocyclization and Wagner-Meerwein rearrangement reactions. (+)/(-)-1 and 3-5 showed potent α-glucosidase inhibitory activity, 3 to 22 times stronger than acarbose, an antidiabetic drug targeting α-glucosidase. Docking results provide a basis to design and develop merosesquiterpenoids as potent α-glycosidase inhibitors.

Development of nanoparticle vaccines utilizing designed Fc-binding homo-oligomers and RBD-Fc of SARS-CoV-2.

The Fc-fused receptor binding domain (RBD-Fc) vaccine for SARS-CoV-2 has garnered significant attention for its capacity to provide effective and specific immune protection. However, its immunogenicity is limited, highlighting the need for improvement in clinical application. Nanoparticle delivery has been shown to be an effective method for enhancing antigen immunogenicity. In this study, we developed bivalent nanoparticle recombinant protein vaccines by assembling the RBD-Fc of SARS-CoV-2 and Fc-binding homo-oligomers o42.1 and i52.3 into octahedral and icosahedral nanoparticles. The formation of RBD-Fc nanoparticles was confirmed through structural characterization and cell binding experiments. Compared to RBD-Fc dimers, the nanoparticle vaccines induced more potent neutralizing antibodies (nAb) and stronger cellular immune responses. Therefore, using bivalent nanoparticle vaccines based on RBD-Fc presents a promising vaccination strategy against SARS-CoV-2 and offers a universal approach for enhancing the immunogenicity of Fc fusion protein vaccines.

The influence of social exclusion on prosocial behavior of college students: the role of relational need threat and regulatory focus.

The present study investigated the impact of social exclusion on prosocial behavior, examining the roles of relational need threat and regulatory focus. Utilizing a questionnaire study with 483 participants (Study 1) and an experimental study with 100 participants (Study 2), we found that (1) social exclusion negatively predicted prosocial behavior; (2) relational need threat fully mediated the relationship between social exclusion and prosocial behavior; and (3) regulatory focus, categorized as either promotion or prevention, moderated this relationship in opposite directions. In conclusion, our findings reveal that social exclusion does indeed trigger prosocial behavior. Meanwhile, relational need threat and regulatory focus have a co-action impact on this process. These findings have been carefully discussed within the frameworks of the temporal need-threat model and the cognitive-affective personality system theory.

MARK2 phosphorylates KIF13A at a 14-3-3 binding site to polarize vesicular transport of transferrin receptor within dendrites.

Neurons regulate the microtubule-based transport of certain vesicles selectively into axons or dendrites to ensure proper polarization of function. The mechanism of this polarized vesicle transport is still not fully elucidated, though it is known to involve kinesins, which drive anterograde transport on microtubules. Here, we explore how the kinesin-3 family member KIF13A is regulated such that vesicles containing transferrin receptor (TfR) travel only to dendrites. In experiments involving live-cell imaging, knockout of KIF13A, BioID assay, we found that the kinase MARK2 phosphorylates KIF13A at a 14-3-3 binding motif, strengthening interaction of KIF13A with 14-3-3 such that it dissociates from TfR-containing vesicles, which therefore cannot enter axons. Overexpression of KIF13A or knockout of MARK2 leads to axonal transport of TfR-containing vesicles. These results suggest a unique kinesin-based mechanism for polarized transport of vesicles to dendrites.

Family Emotional Expressiveness and Adolescents' Cyberbullying Bystanders: The Mediating Role of Empathy.

Background: The significant influence of family emotional expressiveness (FEE) on adolescents' face-to-face social interactions is well-established. However, there has been limited investigation into potential links between FEE and adolescents' online social behaviors, especially cyberbullying bystander behaviors, which are pivotal in cyberbullying incidents. This study aimed to assess the relative importance of different aspects of FEE (positive FEE vs. negative FEE vs. the Positive-to-Negative ratio) in predicting adolescents' cyberbullying bystander behaviors, and the mediating roles of affective and cognitive empathy in these relationships. Methods: A sample of 1,952 adolescents (Mage = 14.18, SD = 1.33) completed questionnaires, including the Family Emotional Expressiveness Questionnaire, Basic Empathy Scale, and Cyberbullying Bystander Behavior Scale. SPSS 26.0 and Mplus 8.3 were used for analysis. Results: (1) Positive FEE exhibited a positive association with protective behavior and a negative association with indifferent behavior. Conversely, negative FEE showed positive associations with reinforcing and indifferent behaviors. However, the Positive-to-Negative ratio did not exhibit significant associations with any of the three bystander behaviors. (2) Negative FEE emerged as relatively more significant than both positive FEE and the Positive-to-Negative ratio in predicting reinforcing and indifferent behaviors. (3) Affective empathy mediated the relationship between positive FEE and reinforcing behavior, while cognitive empathy mediated the relationship between positive FEE and protective and indifferent behaviors. Moreover, cognitive empathy exerted a more influential role than affective empathy in this mediation process. Conclusion: Various aspects of FEE demonstrated distinct relationships with three cyberbullying bystander behaviors, with affective and cognitive empathy playing an important mediating role in the association. This finding holds substantial implications for the development of cyberbullying prevention strategies. Such strategies could target the reduction of negative emotional expression within adolescent families and the cultivation of both cognitive and affective empathy.

Enhancing APE1 detection through apurinic/apyrimidinic site inhibition of DNA polymerase: an innovative, highly sensitive approach.

This study presents an innovative method for the highly sensitive detection of apurinic/apyrimidinic endonuclease 1 (APE1), a crucial biomarker and target for cancer diagnosis and treatment. The method is predicated on our discovery that the apurinic or apyrimidinic site (AP site) can inhibit the activity of Taq DNA polymerase. Subsequent experiments further led to the development of a new amplification method based on the digestion activity of Lambda exonuclease. This approach showed potential to detect trace amounts of APE1 in biological samples with high sensitivity.

Protein Allostery Study in Cells Using NMR Spectroscopy.

Protein allostery is commonly observed in vitro. But how protein allostery behaves in cells is unknown. In this work, a protein monomer-dimer equilibrium system was built with the allosteric effect on the binding characterized using NMR spectroscopy through mutations away from the dimer interface. A chemical shift linear fitting method was developed that enabled us to accurately determine the dissociation constant. A total of 28 allosteric mutations were prepared and grouped to negative allosteric, nonallosteric, and positive allosteric modulators. ∼ 50% of mutations displayed the allosteric-state changes when moving from a buffered solution into cells. For example, there were no positive allosteric modulators in the buffered solution but eight in cells. The change in protein allostery is correlated with the interactions between the protein and the cellular environment. These interactions presumably drive the surrounding macromolecules in cells to transiently bind to the monomer and dimer mutational sites and change the free energies of the two species differently which generate new allosteric effects. These surrounding macromolecules create a new protein allostery pathway that is only present in cells.

SorCS2 is involved in promoting periodontitis-induced depression-like behaviour in mice.

BACKGROUND: Emerging evidence supports the association between periodontitis and depression, although the mechanisms are unclear. This study investigated the role of SorCS2 in the pathogenesis of periodontitis-induced depression. MATERIALS AND METHODS: An experimental periodontitis model was established using SorCS2 knockout mice and their wild-type littermates, and depression-like behaviour was evaluated. The expression of proBDNF signalling, neuronal activity, and glutamate-associated signalling pathways were further measured by western blotting and immunofluorescence. In addition, neuroinflammatory status, astrocytic and microglial markers, and the expression of corticosterone-related factors were measured by immunofluorescence, western blotting, and enzyme-linked immunosorbent assays. RESULTS: SorCS2 deficiency alleviated periodontitis-induced depression-like behaviour in mice. Further results suggested that SorCS2 deficiency downregulated the expression of pro-BDNF and glutamate signalling and restored neuronal activities in mice with periodontitis. Neuroinflammation in the mouse hippocampus was triggered by experimental periodontitis but was not affected by SorCS2 deficiency. The levels of corticosterone and the expression of glucocorticoid receptors were also not altered. CONCLUSION: Our study, for the first time, reveals the critical role of SorCS2 in the pathogenesis of periodontitis-induced depression. The underlying mechanism involves proBDNF and glutamate signalling in the hippocampus, providing a novel therapeutic target for periodontitis-associated depression.

Successful true cavity pathfinding with balloon assisted CTO with bifurcation lesions: Two case reports.

BACKGROUND: Coronary artery disease is a prevalent global cardiovascular ailment, with percutaneous coronary intervention (PCI) standing out as a crucial method for relieving symptoms and enhancing the quality of life in patients with coronary heart disease. However, the presence of concurrent chronic total occlusion (CTO) and bifurcation lesions within coronary arteries elevates the complexity and treatment risks, especially when the entry point of the CTO is ambiguous. OBJECTIVE: This study aims to present an innovative approach for treating CTO complicated with bifurcation lesions, focusing on true cavity pathfinding assisted by a balloon. METHODS: Two cases of CTO patients with concomitant bifurcation lesions are described. One case involves CTO of the left anterior descending artery) combined with anterior non-angle trigeminal lesions, while the other entails CTO of the posterior left artery combined with posterior angle trigeminal lesions. True lumen identification using a balloon and subsequent opening of the CTO blood vessel were performed in both cases. RESULTS: In both cases, the true lumen was successfully located with the assistance of a balloon, leading to the successful opening of the CTO blood vessel. This approach not only simplified the procedure but also reduced procedural difficulty and associated risks of complications compared to traditional guide wire operations. CONCLUSION: The application of true cavity pathfinding assisted by a balloon offers a novel and effective strategy for managing CTO complicated with bifurcation lesions. The method simplifies the procedure, decreases procedural difficulty, and lowers the risk of complications associated with guide wire operations. However, further studies and long-term follow-up data are warranted to validate the reliability and long-term efficacy of this innovative approach.

Xanthones with multiple roles against diabetes: their synthesis, structure-activity relationship, and mechanism studies.

A four-step synthetic process has been developed to prepare 1,3,5,8-tetrahydroxyxanthone (2a) and its isomer 1,3,7,8-tetrahydroxyxanthone (2b). 25 more xanthones were also synthesized by a modified scheme. Xanthone 2a was identified as the most active inhibitor against both α-glucosidase and aldose reductase (ALR2), with IC50 values of 7.8 ± 0.5 µM and 63.2 ± 0.6 nM, respectively, which was far active than acarbose (35.0 ± 0.1 µM), and a little more active than epalrestat (67.0 ± 3.0 nM). 2a was also confirmed as the most active antioxidant in vitro with EC50 value of 8.9 ± 0.1 µM. Any structural modification including methylation, deletion, and position change of hydroxyl group in 2a will cause an activity loss in inhibitory and antioxidation. By applying a H2 O2 -induced oxidative stress nematode model, it was confirmed that xanthone 2a can be absorbed by Caenorhabditis elegans and is bioavailable to attenuate in vivo oxidative stress, including the effects on lifespan, superoxide dismutase, Catalase, and malondialdehyde. 2a was verified with in vivo hypoglycemic effect and mitigation of embryo malformations in high glucose. All our data support that xanthone 2a behaves triple roles and is a potential agent to treat diabetic mellitus, gestational diabetes mellitus, and diabetic complications.

A Simple and Rapid LC-MS/MS Method for the Quantification of Nirmatrelvir/Ritonavir in Plasma of Patients with COVID-19.

The combined prescriptions of nirmatrelvir/ritonavir and other drugs are limited due to potential drug-drug interactions, so therapeutic drug monitoring (TDM) becomes particularly important. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established for determination of the nirmatrelvir/ritonavir in plasma of patients with COVID-19, providing technical and theoretical support for the TDM. Plasma samples were processed by protein precipitation using acetonitrile, and analytes were separated on an Agilent Poroshell 120 SB-C18 (2.1 × 75 mm, 2.7 µm) column at 35°C. Acetonitrile and 0.1% formic acid in water (52 : 48) were utilized as the mobile phases at a flow rate of 0.3 mL/min. In the multiple reaction monitoring (MRM) mode, nirmatrelvir and ritonavir were monitored using precursor/product ions: m/z 500.2/110.1 and 721.3/296.1, respectively, with selinexor as the internal standard. The linear range of both analytes was 2.0 ng/mL to 5000 ng/mL with good inter- and intraday precision and accuracy, and the recovery was 92.0%-107% for nirmatrelvir and 85.7%-106% for ritonavir. Finally, this method was successfully applied to monitor the exposure levels of nirmatrelvir/ritonavir in plasma samples from hemodialysis patients.

Leader-follower UAVs formation control based on a deep Q-network collaborative framework.

This study examines a collaborative framework that utilizes an intelligent deep Q-network to regulate the formation of leader-follower Unmanned Aerial Vehicles (UAVs). The aim is to tackle the challenges posed by the highly dynamic and uncertain flight environment of UAVs. In the context of UAVs, we have developed a dynamic model that captures the collective state of the system. This model encompasses variables like as the relative positions, heading angle, rolling angle, and velocity of different nodes in the formation. In the subsequent section, we elucidate the operational procedure of UAVs in a collaborative manner, employing the conceptual framework of Markov Decision Process (MDP). Furthermore, we employ the Reinforcement Learning (RL) to facilitate this process. In light of this premise, a fundamental framework is presented for addressing the control problem of UAVs utilizing the DQN scheme. This framework encompasses a technique for action selection known as [Formula: see text]-imitation, as well as algorithmic specifics. Finally, the efficacy and portability of the DQN-based approach are substantiated by numerical simulation validation. The average reward curve demonstrates a satisfactory level of convergence, and kinematic link between the nodes inside the formation satisfies the essential requirements for the creation of a controller.

Primary Pulmonary Enteric Adenocarcinoma: Rare Imaging Findings.

INTRODUCTION: Pulmonary enteric adenocarcinoma (PEAC) is an extremely rare variant of lung adenocarcinoma characterized by pathological features similar to those of colorectal adenocarcinoma. It is mostly observed on computed tomography (CT) and positron emission tomography (PET)/CT as solitary or multiple nodules/masses in the lung. It tends to grow rapidly and is difficult to distinguish from lung metastatic colorectal cancer. Herein, we have presented a case of PEAC with special imaging findings. CASE PRESENTATION: A chest CT scan of a 72-year-old man with suspected chronic pneumonia revealed a well-defined consolidation in the upper lobe of the left lung. The lesion was slightly enlarged at the 9-month follow-up, and low FDG accumulation was subsequently observed using 18F-fluorodeoxyglucose (18F-FDG) PET/CT scans. The patient was later diagnosed with PEAC through percutaneous lung biopsy. CONCLUSION: Our case has demonstrated specific imaging findings of PEAC.

Novel Flavonol Alkaloids in Green Tea: Synthesis, Detection, and Anti-Alzheimer's Disease Effect in a Transgenic Caenorhabditis elegans CL4176 Model.

Novel N-ethy-2-pyrrolidinone-substituted flavonols, myricetin alkaloids A-C (1-3), quercetin alkaloids A-C (4a, 4b, and 5), and kaempferol alkaloids A and B (6 and 7), were prepared from thermal reaction products of myricetin, quercetin, kaempferol─l-theanine, respectively. We used HPLC-ESI-HRMS/MS to detect 1-7 in 14 cultivars of green tea and found that they were all present in "Shuchazao," "Longjing 43", "Fudingdabai", and "Zhongcha 108" green teas. The structures of 1-4 and 6 were determined by extensive 1D and 2D NMR spectroscopies. These flavonol alkaloids along with their skeletal flavonols were assessed for anti-Alzheimer's disease effect based on molecular docking, acetylcholinesterase inhibition, and the transgenic Caenorhabditis elegans CL4176 model. Compound 7 strongly binds to the protein amyloid ß (Aß1-42) through hydrogen bonds (BE: -9.5 kcal/mol, Ki: 114.3 nM). Compound 3 (100 µM) is the strongest one in significantly extending the mean lifespan (13.4 ± 0.5 d, 43.0% promotion), delaying the Aß1-42-induced paralysis (PT50: 40.7 ± 1.9 h, 17.1% promotion), enhancing the locomotion (140.0% promotion at 48 h), and alleviating glutamic acid (Glu)-induced neurotoxicity (153.5% promotion at 48 h) of CL4176 worms (p < 0.0001).

The Effectiveness of Traditional Chinese Medicine in Treating Malignancies via Regulatory Cell Death Pathways and the Tumor Immune Microenvironment: A Review of Recent Advances.

Traditional Chinese Medicine (TCM) has achieved high clinical efficacy in treating malignancies in recent years and is thus gradually becoming an important therapy for patients with advanced tumor for its benefits in reducing side effects and improving patients' immune status. However, it has not been internationally recognized for cancer treatment because TCM's anti-tumor mechanism is not fully elucidated, limiting its clinical application and international promotion. This review traced the mechanism of the TCM-mediated tumor cell death pathway and its effect on remodeling the tumor immune microenvironment, its direct impact on the microenvironment, its anti-tumor effect in combination with immunotherapy, and the current status of clinical application of TCM on tumor treatment. TCM can induce tumor cell death in many regulatory cell death (RCD) pathways, including apoptosis, autophagy, pyroptosis, necroptosis, and ferroptosis. In addition, TCM-induced cell death could increase the immune cells' infiltration with an anti-tumor effect in the tumor tissue and elevate the proportion of these cells in the spleen or peripheral blood, enhancing the anti-tumor capacity of the tumor-bearing host. Moreover, TCM can directly affect immune function by increasing the population or activating the sub-type immune cells with an anti-tumor role. It was concluded that TCM could induce a pan-tumor death modality, remodeling the local TIME differently. It can also improve the systemic immune status of tumor-bearing hosts. This review aims to establish a theoretical basis for the clinical application of TCM in tumor treatment and to provide a reference for TCM's potential in combination with immunotherapy in cancer treatment.

Tildrakizumab for moderate-to-severe plaque psoriasis in Chinese patients: A 12-week randomized placebo-controlled phase III trial with long-term extension.

BACKGROUND: There is a need for effective and safe therapies for psoriasis that provide sustained benefits. The aim of this study was to assess the efficacy and safety of tildrakizumab, an anti-interleukin-23p19 monoclonal antibody, for treating moderate-to-severe plaque psoriasis in Chinese patients. METHODS: In this multi-center, double-blind, phase III trial, patients with moderate-to-severe plaque psoriasis were enrolled and randomly assigned (1:1) to receive subcutaneous tildrakizumab 100 mg or placebo at weeks 0 and 4. Patients initially assigned to placebo were switched to receive tildrakizumab at weeks 12, 16, and every 12 weeks thereafter. Patients in the tildrakizumab group continued with tildrakizumab at week 16, and every 12 weeks until week 52. The primary endpoint was the Psoriasis Area and Severity Index (PASI 75) response rate at week 12. RESULTS: At week 12, tildrakizumab demonstrated significantly higher PASI 75 response rates (66.4% [73/110] vs. 12.7% [14/110]; difference, 51.4% [95% confidence interval (CI), 40.72, 62.13]; P <0.001) and Physician's Global Assessment (60.9% [67/110] vs. 10.0% [11/110]; difference, 49.1% [95% CI, 38.64, 59.62]; P <0.001) compared to placebo. PASI 75 response continued to improve over time in both tildrakizumab and placebo-switching to tildrakizumab groups, reaching maximal efficacy after 28 weeks (86.8% [92/106] vs . 82.4% [89/108]) and maintained up to 52 weeks (91.3% [95/104] vs . 87.4% [90/103]). Most treatment-emergent adverse events were mild and not related to tildrakizumab. CONCLUSION: Tildrakizumab demonstrated durable efficacy through week 52 and was well tolerated in Chinese patients with moderate-to-severe plaque psoriasis. TRIAL REGISTRATION: ClinicalTrials.gov , NCT05108766.

Long-term effects of various experiences of parental migration on adult health: A nationwide survey in China.

BACKGROUND: Despite numerous literature studies on the short-term effects of diverse experiences of being left-behind, migrant, or both on children, the research on their long-term effects remains inadequate. The purpose of current study is to explore the long-term impact of being left-behind, migrant or experiencing both during childhood on health in adulthood. Simultaneously, we investigate the impact of psychological resilience on adults in the presence of diverse experiences of parental migration. METHOD: A total of 2,371 samples were selected from 28 provinces in China, consisting of 656 participants who had been left behind but never migrated (PLBNM), 205 participants who had migrated but never been left behind (PMNLB), 265 participants who had both been left behind and migrated (PLBM), and 1,245 participants who had no left-behind/migrant experiences (NLBM). The mental health, health condition, and psychological resilience were measured using the 12-item General Health Questionnaire (GHQ-12), Self-Rated Health, and the Connor-Davidson Resilience Scale (CD-RISC), respectively. RESULTS: The results of the regression model indicated that PLBNM (OR = 2.10, 95% CI [1.59, 2.77], p < .001), PMNLB (1.93, [1.27, 2.94], p < .01), and PLBM (2.01, [1.37, 2.94], p < .001) displayed lower self-rated health compared to NLBM. However, only PLBNM (1.29, [1.05, 1.58], p < .05) reported higher mental health problems compared to NLBM. Our results also showed a strong association between psychological resilience and adults' lower self-rated health (0.72, [0.64, 0.82], p < .001). CONCLUSION: The negative long-term impact of various experiences regarding being left-behind, migrant, or both, on adult's mental health and self-rated health were more pronounced. The Chinese government ought to create unique policy frameworks that offer assistance to those adults.

Association between screen time and physical activity on mental health among preschoolers: a cross-sectional study from Southwest China.

BACKGROUND: Screen time and physical activity behaviors undergo development during early childhood and impact mental health. However, there is limited knowledge regarding the associations between physical activity, screen time, and mental health problems (MHP) in preschoolers. This study examines these associations using a large sample size and brief measures. METHODS: A multistage cluster stratified sampling method was used to conduct an observational cross-sectional study of 19,015 Chinese preschoolers in 2020. Information on physical activity, and screen time was collected by a self-administered questionnaire; MHP was assessed by the parent-reported Strengths and Difficulties Questionnaire (SDQ). Logistic regression models were used to obtain the odds ratios (ORs) and 95% confidence intervals (95% CIs) of preschoolers' MHP associated with screen time, total physical activities, moderate to vigorous physical activity (MVPA), and outdoor physical activities. RESULTS: A total of 19,015 participants from the 19,548 recruited population were included in the analyses (missing rate: 2.73%), 52.60% were boys. 64.01%, 57.96%, 35.98%, and 82.64% of preschoolers were reported to meet total physical activities, MVPA, and outdoor activities with screen time recommendations level. The results of multivariable-adjusted ORs (95% CIs) of preschoolers' MHP for comparisons of different levels of screen time (< 2 h/day, 2-4 h/day,≥4 h/day) show that screen time positively associated with MHP after adjusting for confounders (P < 0.05), but the association was not significant among girls with screen time ≥ 4 h/day. In addition, increased engagement in physical activity was reversely linked to MHP (P < 0.05). A stronger association between MHP and MVPA was observed in boys, however, this association was weakened when the total time spent engaging in MVPA exceeded two hours per day (P < 0.05). CONCLUSION: Less physical activity and more screen time positively relate to MHP, but the relationship differs by type of physical activity, total time, and gender. These findings provide novel insights and evidence supporting for guidelines on physical activity, screen time, and improvement of mental health for preschoolers.