Bidirectional associations between parenting styles and conduct problems in Chinese preschool children: the Shenzhen Longhua Child Cohort Study.

The bidirectional associations between parenting styles and conduct problems in Chinese children attending preschools were rarely discussed. A study covering 171 preschools in Longhua District of Shenzhen, China was conducted among children when they first attended preschools. Parents of children reported the self-perceived parenting styles and their children's conduct problems using validated questionnaires. The bidirectional associations between parenting styles and conduct problems in children were assessed using multivariate linear or logistic regressions in both cross-sectional and cohort settings. In cross-sectional settings, the bidirectional associations were present in all dimensions of parenting styles with children's conduct problems. After 1.01 years of follow-up, increases in parenting dimensions of rejection, control attempts, and favoring subject were significantly associated with children's conduct problems at follow-up, while increases in emotional warmth of parents significantly reduced such risk. In addition, parents of children who had conduct problems at baseline but regressed to normal at follow-up showed decreased scores in negative parenting dimensions. In contrast, among children who developed conduct problems during the study period, the scores of rejection and favoring subject in their parents have increased significantly, while the scores of emotional warmth have decreased. Parent-to-child effect was similar between fathers and mothers, while child-to-parent effect was stronger in fathers than that in mothers. In order to stop the negative feedback loop between poor parenting styles and children's conduct problems, our study underscored the importance of intervention not only in parents but also in their children.

Real-Time Visualization of Solid-Phase Ion Migration Kinetics on Nanowire Monolayer.

Ion migration has been recognized as a critical step in determining the performance of numerous devices in chemistry, biology, and material science. However, direct visualization and quantitative investigation of solid-phase ion migration among anisotropic nanostructures have been a challenging task. Here, we report an in-situ ChemTEM method to quantitatively investigate the solid-phase ion migration process among coassembled nanowires (NWs). This complicated process was tracked within a NW and between NWs with an obvious nanogap, which was revealed by both phase field simulation and ab initio modeling theoretical evaluation. A migration "bridge" between neighboring NWs was observed. Furthermore, these new observations could be applied to migration of other metal ions on semiconductor NWs. These findings provide critical insights into the solid-phase ion migration kinetics occurring in nanoscale systems with generality and offer an efficient tool to explore other ion migration processes, which will facilitate fabrication of customized and new heteronanostructures in the future.

Dynamics and reaction kinetics of coarse-grained bulk vitrimers: a molecular dynamics study.

Vitrimers with dynamic covalent bonds make thermosetting materials plastic, recyclable and self-repairing, and have broad application prospects. However, due to the complex composition of vitrimers and the dynamic bond exchange reactions (BERs), the mechanism behind their unique dynamic behavior is not fully understood. We used the hybrid molecular dynamics-Monte Carlo (MD-MC) algorithm to establish a molecular dynamics model that can accurately reflect BERs, and reveal the intrinsic mechanism of the dynamic behavior of the vitrimer system. The simulation results show that BERs change the diffusion mode of the vitrimer's constituent molecules, which in turn affects the BER and other relaxation dynamics. This provides a theoretical basis and a specific method for the rational design of the rheological properties of vitrimers.

Honokiol induces cell cycle arrest and apoptosis via inhibiting class I histone deacetylases in acute myeloid leukemia.

Honokiol, a constituent of Magnolia officinalis, has been reported to possess potent anti-cancer activity through targeting multiple signaling pathways in numerous malignancies including acute myeloid leukemia (AML). However, the underlying mechanisms remain to be defined. Here, we report that honokiol effectively decreased enzyme activity of histone deacetylases (HDACs) and reduced the protein expression of class I HDACs in leukemic cells. Moreover, treatment with proteasome inhibitor MG132 prevented honokiol-induced degradation of class I HDACs. Importantly, honokiol increased the levels of p21/waf1 and Bax via triggering acetylation of histone in the regions of p21/waf1 and Bax promoter. Honokiol induced apoptosis, decreased activity of HDACs, and significantly inhibited the clonogenic activity of hematopoietic progenitors in bone marrow mononuclear cells from patients with AML. However, honokiol did not decrease the activity of HDACs and induce apoptosis in normal hematopoietic progenitors from unbilicial cord blood. Finally, honokiol dramatically reduced tumorigenicity in a xenograft leukemia model. Collectively, our findings demonstrate that honokiol has anti-leukemia activity through inhibiting HDACs. Thus, being a relative non-toxic agent, honokiol may serve as a novel natural agent for cancer prevention and therapy in leukemia.

Relationship between bedtime, nighttime sleep duration, and anxiety symptoms in preschoolers in China.

Background: Sleep problems in preschoolers are becoming increasingly prominent, and the association between sleep status and anxiety symptoms has attracted growing attention. However, studies investigating the relationship between bedtime and nighttime sleep duration in preschoolers and their anxiety symptoms remain scant. We used the large sample data from the Longhua Cohort Study of Children in Shenzhen, China (LCCS) to analyze the association between bedtime and sleep in preschoolers and their anxiety symptoms. Methods: A cross-sectional study of 69,138 preschoolers in Longhua District, Shenzhen, China was conducted in 2022. Data on sociodemographic characteristics of families, bedtime, nighttime sleep duration of preschoolers, and their anxiety symptoms (measured by the Spence Preschool Children Anxiety Scale) were collected through a structured questionnaire completed by the parents. Using binary logistic regression models, the relationship between bedtime, nighttime sleep duration, and childhood anxiety symptoms was examined. Results: The bedtimes of preschoolers were concentrated between 21:01-22:00 (52.41%). Among the preschoolers, 38.70% had bedtimes later than 22:00, and 75.49% had insufficient nighttime sleep duration. The positive screening rate for anxiety symptoms among preschoolers was 3.50%. After adjusting for confounding factors using binary logistic regression models, compared with preschoolers with bedtime ≤21:00, The OR (95%CI) values of anxiety in preschoolers with bedtime ≥23:01, 22:01-23:00 and 21:01-22:00 were 2.86 (2.21-3.69), 1.51 (1.27-1.79) and 1.48 (1.26-1.76), respectively. Compared with those with sufficient nighttime sleep duration, the OR (95%CI) of children with nighttime sleep duration less than 9 h was 1.36 (1.23-1.51). Conclusion: An association exists between bedtime and nighttime sleep duration in preschoolers and their anxiety symptoms. Preschoolers with 21:00 for bedtime and a nighttime sleep duration of 10 h may have lower anxiety symptoms. These findings support the importance of adequate sleep for preventing anxiety symptoms in children.

Histone deacetylases inhibitor trichostatin A increases the expression of Dleu2/miR-15a/16-1 via HDAC3 in non-small cell lung cancer.

Histone deacetylases (HDACs) inhibitor is a promising new approach to the treatment of lung cancer therapy via inhibiting cell growth and inducing apoptosis. miR-15a and miR-16-1 are important tumor suppressors through modulating B cell lymphoma 2 (Bcl-2), Cyclin D1, D2, and others. However, whether HDACs inhibitor modulates the expression of miR-15a/16-1 in lung cancer is still unknown. The purpose of our study was to identify a new miRNA-mediated mechanism which plays an important role in the anti-cancer effects of HDACs inhibitor. We found HDACs inhibitors trichostatin A (TSA) and sodium butyrate upregulated the expression of miR-15a/16-1, residing in the host tumor suppressor Dleu2 gene, through increasing the histone acetylation in the region of Dleu2/miR-15a/16-1 promoter in lung cancer cells. Moreover, among class Ι HDACs subtypes, only knockdown of HDAC3 by specific siRNA increased the hyperacetylation of Dleu2/miR-15a/16-1 promoter region and finally resulted in the upregulation of miR-15a/16-1. Furthermore, overexpression of miR-15a/16-1, which were always deleted or downregulated in lung cancer cells, effectively suppressed cell growth and reduced colony formation. Finally, TSA reduced the expression of Bcl-2, an important survival protein in lung cancer cells, partly through upregulation of miR-15a/16-1. Therefore, this offers a therapeutic strategy that lung cancer patients who exhibit low level of miR-15a/16-1 or high activity of HDACs may benefit from HDACs inhibitor-based therapy.

Synthesis and biological evaluation of oleanolic acid derivatives as antitumor agents.

Derivatives of oleanolic acid were synthesized and evaluated in vitro for their growth inhibition against human hepatocellular carcinoma cell line (HepG2) and colon cancer cell line (Col-02). Several derivatives exhibited moderate-to-good inhibitory activity, with 3 displaying the most promising inhibition [GI50 = 1.75 µM (HepG2), 0.71 µM (Col-02)]. Structure-activity relationship analyses of these derivatives demonstrated that a 1-en-2-cyano-3-oxo in ring A and a nitro at C-17 were important in retention of the inhibition against HepG2 and Col-02 cells.

Association between screen time and hyperactive behaviors in children under 3 years in China.

Background: Screen time during early life has increased dramatically among Chinese children. Excessive screen time has raised growing concerns about the neuropsychological development of children. The effects of screen exposure on early life and the boundary between screen time and hyperactive behaviors are well worth investigating. We examined associations between screen time and hyperactive behaviors in children under the age of 3 years using data from the Longhua Children Cohort Study (LCCS). Methods: A cross-sectional study was conducted among 42,841 3-year-old children from Longhua District, Shenzhen. Information on socio-demographic characteristics, children's annual screen time since birth, and hyperactive behaviors (measured by the Conners Parental Symptom Questionnaire) was collected through self-administered structured questionnaires completed by the primary caregiver. A series of logistic regression models assessed the association between screen time and hyperactive behaviors. Results: The average daily screen time of children under the age of 3 years was 55.83 ± 58.54 min, and screen time increased with age. Binomial logistic regression analysis found that the earlier the screen exposure, the greater the risk of hyperactive behaviors. Using binary logistic regression model, after controlling for confounding factors, the study found that more screen time was more associated with hyperactive behaviors. For children aged 0-3 years with daily screen time exceeding 90, 120, 150, and 180 min, the risk values for hyperactive behaviors were 1.98 [95% confidence interval (CI): 1.05, 3.78), 2.71 (95%CI:1.38, 5.30), 3.17 (95% CI: 1.50, 6.65), and 4.62 (95% CI: 2.45, 8.71)], respectively. Conclusion: Early screen exposure may be associated with hyperactive behaviors in children under the age of 3 years. More than 90 min of screen time per day in children under 3 years was associated with hyperactive behaviors. The findings support the importance of screen time interventions for children under 3 years.

[Bacterial 16S rRNA genes and expression of IL-1ß, TNF-α and IgA in prostate tissues].

OBJECTIVE: To investigate the role of bacteria in the etiology of chronic prostatitis. METHODS: Complete prostate specimens were obtained at autopsy from 192 organ donors (aged 20 - 38 years old) during 2002 to 2008 who died of non-prostatic diseases. One tissue taken from the peripheral prostatic zone according to McNeal was divided into two pieces. One piece of tissue was taken for routine pathological examinations and immunohistochemical studies of interleukin (IL)-1ß, tumor necrosis factor-α (TNF-α) and IgA. Another one was taken for PCR assay to detect the bacterial 16S rRNA genes (16S rDNA). RESULTS: Of 192 prostate specimens, 64 (33.3%) had pathological changes of chronic prostatitis and 38 (19.8%) specimens was positive for bacterial 16S rDNA. Positive rates of 16S rDNA in chronic prostatitis and non-prostatitis specimens were 50.0% (32/64) and 4.6% (6/128) respectively (χ(2) = 55.185, P < 0.001). Expressions of IL-1ß, TNF-α and IgA in specimens of chronic prostatitis were significantly higher than those in non-prostatitis specimens (P < 0.001). A positive correlation could be found among three immunohistochemical indicators (P < 0.01). In 64 specimens with chronic prostatitis, a significant expression of IL-1ß, TNF-α and IgA was more often demonstrated in 16S rDNA positive group than in 16S rDNA negative group (P < 0.001). CONCLUSIONS: The up-regulations of bacterial 16S rDNA, cytokines and immunoglobulin A are involved in inflammatory response of chronic prostatitis. Bacterial infection may be an important cause of chronic prostatitis.

[Investigation on occupational hazards of ultraviolet light, sunscreen awareness and behaviors in Wuhan city traffic police].

OBJECTIVE: To understand the awareness of occupational hazards to ultraviolet (UV) and sunscreen awareness, protective measures in Wuhan City traffic police on duty outside. METHODS: The investigation included questionnaire survey in Wuhan City 367 traffic police on duty outside, talk with them face to face, fill in the questionnaires, and medical examine skin of exposed parts of body of them and 134 Wuhan City administration staffs. RESULTS: They understand UV harm to the human body and skin well (94.8% of them know that UV harm to skin), did not understand sun skin care and protective measures enough, and did not adopt enough sun skin care and protective measures (only 3.8% of them use sun skin care more than twice); but contrast to older persons, younger traffic police had better understanding of UV radiation damage on the human body and the skin, and sunscreen products and protective measures, paid more attention to sunscreen, and had less chance of sunburn (in the past 5 years, 18.3% of younger traffic police had sunburnt more than 3 times, but for older traffic police, the number is 30.3%). Traffic police had more skin problems than administration staffs in exposed parts of body (Traffic police face appears oily and large pores, facial pigmentation spots, face telangiectasia, deep wrinkles crude rates respectively were 73.7%, 40.4%, 36.5%, 10.4%, but for administration staffs, the numbers respectively were 26.1%, 15.7%, 15.7%, 1.5%). CONCLUSION: UV can induce skin problems in exposed parts of body. The traffic police should be enhanced the publicity and education on UV-related knowledge and occupational hazards, especially for older traffic police.

Simulation Study of Process-Controlled Supramolecular Block Copolymer Phase Separation with Reversible Reaction Algorithm.

A supramolecular diblock copolymer formed by reversible bonds between the two blocks shows a rich microphase separation behavior and has great application potential in stimuli-responsive materials. We propose a novel method to describe supramolecular reactions in dissipative particle dynamics, which includes a reversible reaction to accurately reproduce the strength, saturation, and dynamic properties of the reversible bonds in the simulations. The thermodynamic properties and dynamic processes of the supramolecular diblock copolymer melts in both equilibrium and non-equilibrium states were studied using this method. The simulation results show that the method can faithfully characterize phase behaviors and dynamic properties of supramolecular diblock copolymer melts, especially in a non-equilibrium state, which provides a novel tool to unveil self-assembly mechanism and describe the properties of supramolecular block copolymers.

Synthesis and characterization of new liver targeting 5-fluorouracil-cholic acid conjugates.

The objective of this work was to develop a liver-specific antihepato carcinoma agent. A series of 5-fluorouracil / cholic acid conjugates (5-FU-cholic acid conjugates) were prepared and tested for their chemical characteristics and bio-distribution properties. The in-vitro stability trial showed 5-FU-cholic acid conjugates could be completely hydrolyzed by heating at 70 degrees C in an acidic solution, pH = 1, for 5 min. The fast and complete hydrolysis of these compounds could be compatible with a fast separation and analysis method to shorten the analysis time. The decomposition speeds of the 5-FU-cholic acid conjugates in different organs of mice at several time points after oral administration were evaluated by measuring the concentrations of regenerated 5-FU in organ tissue. The results were compared with those of the controls, which was a group of mice orally taking 5-FU. The concentrations of 5-FU in mice liver tissue were remarkably increased after oral administration of the prodrugs, and were much larger than if only orally administered 5-FU. The results suggested the feasibility to improve therapeutic efficiency of liver targeting treatments by using cholic acid as the vector of drugs.

Phenotypic plasticity vs. local adaptation in quantitative traits differences of Stipa grandis in semi-arid steppe, China.

Whether plants are able to adapt to environmental changes depends on their genetic characteristics and phenotypic plastic responses. We investigated the phenotypic responses of 7 populations of an important dominant species in semi-arid steppe of China - Stipa grandis, and then distinguished which adaptive mechanism(s), phenotypic plasticity or local adaptation, was/were involved in this species to adapt to environmental changes. (1) All traits were significantly influenced by the interaction of population and growth condition and by population in each condition, and inter-population variability (CVinter) was larger in the field than in the common garden for 8/9 traits, indicating that both phenotypic plasticity and genetic differentiation controlled the phenotypic differences of S. grandis. (2) From a functional standpoint, the significant relationships between the values of traits in the common garden and the environmental variables in their original habitats couldn't support local habitat adaptation of these traits. (3) Low CVintra, low quantitative differentiation among populations (Q ST ), and low plasticity shown in the western populations indicated the very low adaptive potential of S. grandis to environmental changes. (4) From the original habitats to the common garden which is far away from S. grandis distribution region, positive phenotypic responses were found in several populations, indicating that some original habitats have become unfavorable for S. grandis.

Characterization and molecular cloning of dabocetin, a potent antiplatelet C-type lectin-like protein from Daboia russellii siamensis venom.

A novel C-type lectin-like protein, dabocetin, was purified from Daboia russellii siamensis venom. On SDS-polyacrylamide gel electrophoresis, it showed a single band with an apparent molecular weight of 28 kDa and two distinct bands with the apparent molecular weights of 15.0 kDa and 14.5 kDa under non-reducing and reducing conditions, respectively. cDNA clones containing the coding sequences for dabocetin alpha and beta subunits were isolated and sequenced. The deduced protein sequences of both subunits were confirmed by N-terminal amino acid sequencing and trypsin-digested peptide mass fingerprinting. Dabocetin did not induce platelet aggregation in platelet-rich plasma. It also had little effect on the platelet aggregation induced by ADP, TMVA or stejnulxin. Whereas, dabocetin inhibited ristocetin-induced platelet agglutination in platelet-rich plasma in a dose-dependent manner with an IC50 value of 0.35 microM. Flow cytometry analysis showed that dabocetin significantly inhibited mAb SZ2 binding to platelet membrane glycoprotein Ib alpha, indicating that platelet membrane glycoprotein Ib is involved in the inhibitory effect of dabocetin on ristocetin-induced platelet agglutination.

[A IL-6R antagonist 2520A produced by a fungal species].

AIM: To isolate IL-6R antagonists from the cultured broth of the strain Torulomyces ovatus. METHODS: Various column chromatographyes were used to separate and purify the compounds with IL-6R antagonist activity. The spectral data and physic-chemical properties were measured for structure identification. RESULTS: One compound namely 2520 was isolated from the cultured broth of Torulomyces ovatus. CONCLUSION: 2520A is a known compound (ferrichrome). It is first reported about its antagonistic activity of IL-6R and identification of iron atom in its structure.

Inhibition of mitochondria responsible for the anti-apoptotic effects of melatonin during ischemia-reperfusion.

OBJECTIVE: To investigate a possible mechanism responsible for anti-apoptotic effects of melatonin and provide theoretical evidences for clinical therapy. METHODS: Ischemia-reperfusion mediated neuronal cell injury model was constructed in cerebellar granule neurons (CGNs) by deprivation of glucose, serum and oxygen in media. After ischemia, melatonin was added to the test groups to reach differential concentration during reperfusion. DNA fragmentation, mitochondrial transmembrane potential, mitochondrial cytochrome c release and caspase-3 activity were observed after subjecting cerebellar granule neurons to oxygen-glucose deprivation (OGD). RESULTS: The results showed that OGD induced typical cell apoptosis change, DNA ladder and apoptosis-related alterations in mitochondrial functions including depression of mitochondrial transmembrane potential (its maximal protection ratio was 73.26%) and release of cytochrome c (its maximal inhibition ratio was 42.52%) and the subsequent activation of caspase-3 (its maximal protection ratio was 59.32%) in cytoplasm. Melatonin reduced DNA damage and inhibited release of mitochondrial cytochrome c and activation of caspase-3. Melatonin can strongly prevent the OGD-induced loss of the mitochondria membrane potential. CONCLUSION: Our findings suggested that the direct inhibition of mitochondrial pathway might essentially contribute to its anti-apoptotic effects in neuronal ischemia-reperfusion.

[Detection of 16S ribosomal RNA gene of bacteria in prostate tissues of adults].

OBJECTIVE: To investigate the role of bacteria in chronic prostatitis. METHODS: Complete specimens of prostate were obtained from 140 organ donors, aged 20 - 35, at autopsy. A piece of tissue was collected from the peripheral zone of prostate from each specimen and was divided into 2 parts to undergo pathological examination and PCR so as to detect the 16S ribosomal RNA (16S rRNA) gene of bacteria. RESULTS: Focal mild inflammation was shown in 46 of the 104 specimens (32.9%), including interstitial inflammation in 42 specimens, inflammation in both interstitial and body of gland in 3 specimens, and perigladulitis in 1 specimen. Twenty-seven of the 140 specimens (19.3%) were positive in 16S rRNA gene. The positive rate of 16S rRNA gene of the specimens with prostatitis was 48.9%, significantly higher than that of the specimens without prostatitis (5.3%, P < 0.001). CONCLUSION: Bacteria may play an important role in the pathogenesis of chronic prostatitis.

Molecular characterization of a weak fibrinogen-clotting enzyme from Trimeresurus jerdonii venom.

A fibrinogen-clotting enzyme designed as jerdonobin-II was isolated from the venom of Trimeresurus jerdonii. It differed in molecular weight and N-terminal sequence with the previously isolated jerdonobin, a thrombin-like enzyme from the same venom. The enzyme consists of a single polypeptide chain with molecular weights of 30,000 and 32,000 under non-reducing and reducing conditions, respectively. Jerdonobin-II showed weak fibrinogen clotting activity and its activity unit on fibrinogen was calculated to be less than one unit using human thrombin as standard. The precursor protein sequence of jerodonobin-II was deduced from cloned cDNA sequence. The sequence shows high similarity (identity=89%) to TSV-PA, a specific plasminogen activator from venom of T. stejnegeri. Despite of the sequence similarity, jerdonobin-II was found devoid of plasminogen activating effect. Sequence alignment analysis suggested that the replacement of Lys239 in TSV-PA to Gln239 in jerdonobin-II might play an important role on their plasminogen activating activity difference.

[Methylglyoxal inhibits human umbilical vein cell migration in vitro by down-regulating integrinß3].

OBJECTIVE: To explore the effects of methylglyoxal on endothelia cell migration. METHODS: Human umbilical vein endothelial cells (HUVECs) were stimulated by serial concentrations of methylglyoxal (MGO, 0, 25, 50, 100 and 200 µmol/L) for 24 h, and the cell migration was assessed by scratch wound and Transwell assay. The expression of integrin ß3 in the treated cells was examined by immunoblotting, and the effect of an anti-ß3 antibody, LM609, on cell migration was investigated. RESULTS: Methylglyoxal significantly inhibited HUVEC migration in a concentration-dependent manner (P<0.05). Methylglyoxal decreased the expression of integrin ß3 in a time- and concentration-dependent manner (P<0.05). LM609 also significantly inhibited HUVEC migration (P<0.05). CONCLUSION: Methylglyoxal inhibits HUVEC migration in vitro by down-regulating integrin ß3 expression.