MicroRNA-155 inhibition attenuates myocardial infarction-induced connexin 43 degradation in cardiomyocytes by reducing pro-inflammatory macrophage activation.

Background: Degradation of pro-inflammatory macrophage-mediated connexin 43 (Cx43) plays an important role in post-myocardial infarction (MI) arrhythmogenesis, microRNA (miR)-155 produced by macrophages has been shown to mediate post-MI effects. We hypothesized that miR-155 inhibition attenuated MI-induced Cx43 degradation by reducing pro-inflammatory macrophage activation. Methods: MI was induced by permanent ligation of the left anterior descending coronary artery in male C57BL/6 mice. Lipopolysaccharide (LPS)-stimulated mice bone marrow-derived macrophages (BMDMs) and hypoxia-induced neonatal rat cardiomyocytes (NRCMs) were used in vitro models. qRT-PCR, Western-blot and immunofluorescence were used to analyze relevant indicators. Results: The expression levels of miR-155, interleukin-1 beta (IL-1ß), and matrix metalloproteinase (MMP)7 were higher in MI mice and LPS-treated BMDMs than in the sham/control groups, treatment with a miR-155 antagomir reversed these effects. Moreover, miR-155 inhibition reduced ventricular arrhythmias incidence and improved cardiac function in MI mice. Cx43 expression was decreased in MI mice and hypoxia-exposed NRCMs, and hypoxia-induced Cx43 degradation in NRCMs was reduced by application of conditioned medium from LPS-induced BMDMs treated with the miR-155 antagomir, but increased by conditioned medium from BMDMs treated with a miR-155 agomir. Importantly, NRCMs cultured in conditioned medium from LPS-induced BMDMs transfected with small interfering RNA against IL-1ß and MMP7 showed decreased hypoxia-mediated Cx43 degradation, and this effect also was diminished by BMDM treatment with the miR-155 agomir. Additionally, siRNA-mediated suppressor of cytokine signaling 1 (SOCS1) knockdown in LPS-induced BMDMs promoted Cx43 degradation in hypoxia-exposed NRCMs, and the effect was reduced by the miR-155 inhibition. Conclusions: MiR-155 inhibition attenuated post-MI Cx43 degradation by reducing macrophage-mediated IL-1ß and MMP7 expression through the SOCS1/nuclear factor-κB pathway.

Sensitive periods for the effect of bullying victimization on suicidal behaviors among university students in China: The roles of timing and chronicity.

OBJECTIVE: To examine whether timing and chronicity of bullying victimization (BV) play a significant role in linking exposure to BV to suicidal behaviors in university students. METHODS: A multistage stratification sampling method was used to select a sample of 4034 university students (18-23 years, mean age 20.38±1.35 years, 41.9% female). We used latent class analysis and developmental-stage-based characterizations of BV timing and chronicity to explore the sensitive periods for the effect of BV on suicidal behaviors. RESULTS: The prevalence rates of suicidal ideation, plans and attempts among our study participants were 9.9%, 3.0% and 1.3%, respectively. BV during primary school (OR = 2.12, 95% CI: 1.55-2.90) and secondary school (OR = 2.65, 95% CI: 1.80-3.90) was associated with suicidal ideation among university students. We identified four classes of life-course BV experiences (low BV, 73.8%; moderate BV, 18.6%; secondary school BV, 4.4% and persistent BV, 3.2%). Persistent BV was associated with 2.50 times (95% CI: 1.56-3.98), 2.98 times (95% CI: 1.48-6.02), and 6.13 times (95% CI: 2.48-15.14) higher risk of suicide ideation, plans, and attempts, respectively. Both moderate BV (OR = 1.75, 95% CI: 1.35-2.26) and secondary school BV (OR=2.01, 95% CI: 1.29-3.12) were positively correlated with suicidal ideation. Furthermore, there was a dose-response relationship between the number of periods of BV and suicidal behaviors. LIMITATIONS: This study was a cross-sectional study based on self-reported measures, especially BV experiences in each school stage. CONCLUSIONS: This study identifies sensitive periods for the effect of BV on suicidal behaviors among university students in China.

Improved Sliding Mode Control for Finite-Time Synchronization of Nonidentical Delayed Recurrent Neural Networks.

This brief further explores the problem of finite-time synchronization of delayed recurrent neural networks with the mismatched parameters and neuron activation functions. An improved sliding mode control approach is presented for addressing the finite-time synchronization problem. First, by employing the drive-response concept and the synchronization error of drive-response systems, a novel integral sliding mode surface is constructed such that the synchronization error can converge to zero in finite time along the constructed integral sliding mode surface. Second, a suitable sliding mode controller is designed by relying on Lyapunov stability theory such that all system state trajectories can be driven onto the predefined sliding mode surface in finite time. Moreover, it is found that the presented control approach can be conveniently verified and does not need to solve any linear matrix inequality (LMI) to guarantee the finite-time synchronization of delayed recurrent neural networks. Finally, three numerical examples are exploited to demonstrate the effectiveness of the presented control approach.

The association between childhood physical disability or long-term health problems and depression among adolescents in China: Mediating effect of childhood maltreatment.

BACKGROUND: Increasing evidence has suggested that childhood maltreatment might mediate the association between physical disability or chronic illness and depression among adolescents. We sought to identify whether childhood maltreatment mediated the relationship between physical disability or long-term health problems and depression in Chinese adolescents. METHOD: A total of 5726 middle and high school students aged 12-18 years old were chosen to participant in this study. Participants completed the self-reported questionnaire on childhood physical or long-term health problems, childhood maltreatment and depression. RESULTS: The results showed that there were significant differences of childhood maltreatment, depression between adolescents with childhood physical disability or long-term health problems and those without. Physical abuse, sexual abuse, emotional abuse, physical neglect and emotional neglect mediated the association between childhood physical disability or long-term health problems and depression accounting for 8.7%, 20.6%, 14.5%, 16.3% and 14.7% of the total effect of physical disability or long-term health problems on depression in each single mediator model respectively, whereas the indirect effect of emotional abuse and sexual abuse in the association between physical disability or long-term health problems and depression explained 15.6% and 8.0% of the total effect in a multiple mediation model respectively. CONCLUSION: Childhood physical disability or long-term health problems was associated with the increased risk for depression, and the associations between childhood physical disability and long-term health problems and depression were partially mediated by childhood maltreatment experiences. Childhood maltreatment exposure should be considered to prevent depression among adolescents with childhood physical disability or long-term health problems.

Association between different stages of precollege school bullying and murder-related psychological behaviors among college students in Anhui Province, China.

Little is known about the relationship between precollege school bullying and murder-related psychological behaviors. The present study aims to examine that relationship in Chinese college students using a cross-sectional study. Self-report data were collected from 4034 college students in Anhui Province using a proportional stratified cluster sampling method. Four types of school bullying (i.e., physical, verbal, relational, and cyber) with bullies and victims and two periods (i.e., primary and secondary) were measured. The prevalence rates of murderous ideation, plans, preparation, and attempts were 6.9%, 2.5%, 1.8%, 1.4%, respectively. Different stages of precollege cyber bullying were associated with murder-related psychological behaviors for both bullies (primary: AORs = 2.78 to 15.67; secondary: AORs = 2.43 to 9.99; both periods: AORs = 2.26 to 14.04) and victims (primary: AORs = 2.87 to 16.57; secondary: AORs = 1.89 to 4.49; both periods: AORs = 3.68 to 21.48). A dose-response relationship was found, such that college students with a bullying perpetration index of two types and more were more likely to have murder-related psychological behaviors than those who were not bullied. Notably, both primary and secondary school bullying, especially cyber forms, were more likely to be associated with murder-related psychological behaviors. Therefore, it is necessary to develop school bullying preventive measures beginning in primary school.

Is involvement in school bullying associated with increased risk of murderous ideation and behaviours among adolescent students in China?

BACKGROUND: School bullying is a destructive behaviour common among adolescents that can sometimes escalate to criminal activity. This study aimed to examine the association between four types of school bullying (i.e., physical, verbal, relational, and cyber) and murderous ideation and behaviours (i.e., ideation, plans, preparation, and attempts) among adolescent students. METHODS: Data were collected from 5726 middle and high school students using self-administered questionnaires in December 2013. The participants were selected using a 3-stage random cluster-sampling strategy. The participants were asked about the frequency of their bullying experiences in the past two months and the frequencies of their murderous ideation and behaviours in the past six months. Multivariate logistic regressions were performed to explore the association between school bullying and murderous ideation and behaviours. RESULTS: Each type of school bullying perpetration was associated with murderous ideation and behaviours, as was each type of bullying victimization. Students who experienced more types of school bullying perpetration and victimization were more likely to report murderous ideation and behaviours. Moreover, the number of types of bullying perpetration and victimization had a dose-response association with murderous ideation and behaviours (aOR min = 1.45, aOR max = 2.72), as did the frequency of involvement in bullying perpetration and victimization (aOR min = 1.33, aOR max = 2.00). Being a bully-victim was a risk factor for murderous ideation and behaviours (aOR min = 3.88, aOR max = 7.24). CONCLUSIONS: Each type of school bullying was associated with an increased risk for murderous ideation and behaviours among adolescents. Dose-response relationships between the frequency of bullying and number of bullying types experienced and murderous ideation and behaviours were found in this study. Future studies are warranted to confirm our findings and explore the mechanisms underlying the relationship between school bullying and murderous ideation and behaviours.

Is childhood maltreatment associated with murderous ideation and behaviors in adolescents in China?

Previous research has revealed associations between childhood maltreatment (CM) and adverse health behaviors. However, little is known about the relationship between CM and adolescent murderous ideation and behaviors. A total of 5726 middle and high school students completed the Childhood Trauma Questionnaire-Short Form and the Murderous Ideation and Behaviors Questionnaire. The findings revealed that the prevalence rates for murderous ideation, plans, preparation, and attempts were 9.9%, 2.8%, 1.3%, and 0.6%, respectively. The results of multinomial logistic regression models indicated that adolescents who experienced CM were more likely to exhibit murderous ideation and behaviors, with adjusted odds ratios (AORs) ranging from 2.55 to 22.31. Additionally, a significant dose-response relationship was found between the number of CM types experienced and murderous ideation and behaviors (AORs ranging from 1.52 to 2.45). The odds of participants who had experienced three or five types of CM were significantly associated with murderous ideation and behaviors, with AORs ranging from 4.55 to 28.30 and from 5.26 to 85.45, respectively. The findings highlighted that adolescents who engaged in murderous ideation and behaviors were more likely to have a personal history of CM and revealed a dose-response relationship between the number of CM types and murderous ideation and behaviors.

Global fast dynamic terminal sliding mode control for a quadrotor UAV.

A control method based on global fast dynamic terminal sliding mode control (TSMC) technique is proposed to design the flight controller for performing the finite-time position and attitude tracking control of a small quadrotor UAV. Firstly, the dynamic model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. Secondly, the dynamic flight controllers of the quadrotor are formulated based on global fast dynamic TSMC, which is able to guarantee that the position and velocity tracking errors of all system state variables converge to zero in finite-time. Moreover, the global fast dynamic TSMC is also able to eliminate the chattering phenomenon caused by the switching control action and realize the high precision performance. In addition, the stabilities of two subsystems are demonstrated by Lyapunov theory, respectively. Lastly, the simulation results are given to illustrate the effectiveness and robustness of the proposed control method in the presence of external disturbances.

[Effects of on-pump beating-heart coronary artery bypass grafting for left-main patients].

OBJECTIVE: To explore the value of on-pump beating-heart coronary artery bypass grafting (OnP-BH CABG) for left-main patients with coronary heart disease through a comparative study with conventional coronary artery bypass grafting (CCABG). METHODS: The clinical data were retrospectively analyzed for 66 patients of OnP-BH and 48 control cases undergoing CCABG from January 2009 to January 2012 at Department of Cardiac Surgery, People's Hospital of Zhengzhou University. RESULTS: OnP-BH group had a better clinical outcome than CCABG group. There were obvious statistical difference in cardiopulmonary bypass (CPB) time, mean ventilation time, intensive care unit stay and recovery time of plasma cardiac troponin I (OnP-BH group vs CCABG group:(89 ± 25) vs (117 ± 28) min, (15 ± 14) vs (27 ± 19) h, (57 ± 27) vs (79 ± 34) h, (6.2 ± 1.8) vs (7.0 ± 2.4) d, all P < 0.05). The data of preoperative cTnI showed no significant difference between two groups (P > 0.05) .However, after CPB, significant intergroup difference existed in the level of cTnI (µg/L) OnP-BH group vs CCABG group: (0.5 h after CPB: (0.132 ± 0.022) vs (0.265 ± 0.014) , 1 h after CPB: (0.341 ± 0.027) vs (0.572 ± 0.046) , 1 h after operation: (0.641 ± 0.036) vs (0.932 ± 0.047) , 6 h after operation: (1.212 ± 0.765) vs (1.627 ± 0.542) and 24 h after operation: (1.496 ± 0.263) vs (1.734 ± 0.328) , all P < 0.05). CONCLUSIONS: On-pump beating-heart coronary artery bypass grafting is a feasible surgical approach for left-main patients. And it has a low risk and causes less myocardial damage.

[Study on the solid state transformation of PET/nano-CaCO3 composites by variable temperature FTIR spectroscopy].

Solid state transformation of crude poly (ethylene terephthalate)(PET) and PET/nano-CaCO3 (MPET) composites were studied by variable temperature FTIR spectroscopy during the heating process from 40 to 250 degrees C. The effects of nanometer calcium carbonate(nano-CaCO3) on the solid state transformation and crystal correlation bands of MPET composites were analyzed by the curves of the ratio of 1 342 and 1 410 cm(-1) absorbency(A1 342/A1 410) with temperature increasing, and together with DSC curves in the same condition. The results showed that the crystallization degrees of crude PET and MPET are obviously different in this condition by adding nano-CaCO3 particles as inhomogeneous nucleating agents.

[Study on the peaks linked to the crystalline of L-LA with variable temperature FTIR spectra method].

Variable temperature FTIR spectra method was used to study the crystalline spectra of crystal compounds. In the present paper, the sample of L-LA was synthesized and characterized by FTIR, NMR and DSC. It was found that the two peaks in therange of 800-770 cm(-1) changed sharply at 95 degrees C after being investigated by FTIR spectra between 15-120 degrees C. When the temperature increased, these peaks remained almost unchanged, but they returned to the original state after annealing. It was deduced that these two peaks are linked to the crystalline of L-LA.

[IR study on the thermal decomposition IR of the cationic fenugreek gum].

The title complexes shown as cationic fenugreek gum were prepared. The thermal decomposition process of fenugreek gum and cationic fenugreek gum was studied quantitatively by means of thermogravimetric analysis an dinfrared spectroscopic measurement of samples after heating at different temperatures. Additionally, according to the fact that the absorbance peak changes and theanalysis of TG-IR of cationic fenugreek gum at different temperatures, it can be drawn that the thermal decomposition of the cationic fenugreek gum might lead to a possible thermal-cracking process.

[Infrared spectroscopic investigation on complexes formed from cupric fluoborate and cupric butyrate with Bis (diphenylphosphino) alkane ligands].

The Bis (diphenylphosphino) alkane series ligands and its series of complexes formed from Cu(BF4)2 and Cu(C3H7COO)2 respectively were studied by infrared spectral analysis. This paper discusses the spectral classification and the change regularity of related spectra before and after the Cu(I) complexes were formed. The possible structure model of the formed complexes was discussed, based on the element analysis, powder X-ray diffraction analysis, and thermal gravity analysis.