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To explore the factors associated with occurrence of suicidal risk after treatment of Selective Serotonin Reuptake Inhibitor (SSRI) in bipolar disorder with their first depressive episode.
One hundred and seventy seven bipolar patients were enrolled in this retrospective study. Demographic and clinic features between non-occurrence of suicidal risk group and occurrence of suicidal risk group were compared. Stepwise Logistic regression model was used to identify the associated factors. Concordance statistics (i.e. the area under the ROC curve) was used to compute the discrimination of the associated factors, and Hosmer-Lemeshow goodness-of-fit statistic was used to measure the goodness-of-fit.
One hundred and fifty four patients were included in non-occurrence of suicidal risk group, while twenty three were included in occurrence of suicidal risk group. Clinical features associated with occurrence of suicidal risk after treatment of SSRI in bipolar disorder were as follows: symptom of irritability (OR=4.04, 95 CI:1.40-11.67) and psychotic symptom (OR=6.23, 95 CI:1.40-27.56).
This study demonstrated indicated that psychotic symptom and symptom of irritability were associated with occurrence of suicidal risk after treatment of SSRI in bipolar disorder, and it suggested that these two symptoms might be potential to be the predictors of occurrence of suicidal risk after treatment of SSRI in bipolar disorder.
Studies revealed that prenatal stress (PS) may increase the vulnerability to depression in their offspring, and ERK-CREB signal system might play a role in its mechanism.
Objectives and aims
The present study investigated the effect of MK-801 on depressive-like behavior and its impacts on ERK2, CREB, Bcl-2 mRNA expression in PS female rat offspring.
The pregnant rats were randomly divided into three groups, the control group (Con) was left undisturbed, the PS-saline group (PS-saline) and the PS-MK-801 group (PS-MK-801) were subjected to restraint stress on days 14–20 of pregnancy three times daily for 45 min, and received an i.p. administration of saline or MK-801(sigma, 0.2 mg/kg) 30 min before the first stress respectively. Forced swimming test was undertaken to assess depressive-like behavior in one month female offspring. ERK2, CREB, Bcl-2 mRNA in the hippocampus, frontal cortex, and striatum were detected by RT-PCR.
PS-saline spent significantly more immobile time compared to Con and PS-MK-801 (P < 0.05). ERK2 and CREB mRNA expression in hippocampus and frontal cortex was significantly decreased in PS-saline compared to Con and PS-MK-801 (P < 0.05), while in striatum CREB mRNA expression in PS-saline was lower than Con (P < 0.05). Bcl-2 mRNA expression in hippocampus and striatum was significantly decreased in PS-saline (P < 0.05), and in frontal cortex, its expression was significantly lower in PS-saline and PS-MK-801 (P < 0.05).
PS may suppress ERK-CREB signal pathway in female offspring rats, which could be partly prevented by MK- 801. (Supported by National Natural Science Foundation of China, No: 30970952).
Studies have convinced that the rodents' exposure to prenatal stress (PNS) may induce depression and anxiety to their offspring. We focused on the glutamatergic system to explore the mechanisms.
Objectives and aims:
By examining EAAT2,EAAT3 (Excitatory Amino Acid Transporter 2,3), which are the only substances to inactivate glutamate in nervous system, we explored the effect of PNS on glutamatergic system.
Pregnant rats were assigned to Control group (CON), Middle period of PNS group (MPS) and Late period of PNS group (LPS). MPS and LPS rats were exposed to restraint stress on days 7–13, 14–20 of pregnancy three times daily for 45 min. EAAT2 and EAAT3 mRNA expression in the hippocampus, frontal cortex, and striatum of one month rat offspring were checked by RT-PCR.
For the female offspring, EAAT2 mRNA expression of hippocampus in LPS and MPS was significantly lower compared to CON(P = 0.008,p = 0.003); EAAT2 and EAAT3 mRNA expression of frontal cortex in LPS were significantly lower than CON (p = 0.003,p = 0.013). for the male offspring, EAAT2 and EAAT3 mRNA expression of hippocampus in LPS and MPS were significantly lower (p = 0.005, p = 0.05); EAAT2 mRNA expression of frontal cortex was significantly lower in LPS (p = 0.022); EAAT2 mRNA in LPS group and MPS were significantly lower (p = 0.009, p = 0.014), and EAAT3 mRNA expression of striatum in MPS was significantly lower (p = 0.049).
Decreased EAAT2 and EAAT3 of PNS may explain the increase of glutamate in synaptic cleft and its downstream excitotoxicity. (Supported by National Natural Science Foundation of China, No: 30970952)
Epidemiological studies have convinced that prenatal stress (PS) might cause offspring depression.
Objectives and aims:
Our pervious research work certified that PS can increases the glutamate level of hippocampus of rat offspring, which inspired us to explore the pathogenesis of depression by focusing on glutamatergic system.
Pregnant rats were randomly assigned to control group (CON), mid prenatal stress group (MPS) and late prenatal stress group (LPS). The pregnant rats of MPS and LPS were exposed to restraint stress on days 7–13, 14–20 of pregnancy three times for 45 min respectively. Tail suspension test (TST) was performed to examine the depression like behavior and Western-blot were used to test phosphorylated GluR1(pGluR1) of AMPAR expression in the hippocampus, striatum and frontal cortex of one month rat offspring.
For both male and female offspring, the time of immobility of TST in LPS (156±11, 155±12) and MPS (173±15, 155±12) was significantly longer (P< 0.05) than CON(118±8,113±12), the latency in MPS (18±3, 24±3) was significantly shorter (P< 0.05) than CON (30±5, 58±11). The pGluR1 expression in hippocampus and frontal cortex in LPS (1.77±0.45, 1.00±0.09) and MPS (1.65±0.51, 1.05±0.18) were significantly lower (P< 0.05) than CON (3.72±0.86, 2.05±0.34) in male rat offspring.
It is suggested that the PS may induce depression like behavior in rat offspring, and glutamate receptors subunit pGluR1 might be involved in the etiology of depression.
(The research is supported by National Natural Science Foundation of China, No: 30970952, 18110059).
Chitinase is responsible for insect chitin hydrolyzation, which is a key process in insect molting and pupation. However, little is known about the chitinase of Spodoptera exigua (SeChi). In this study, based on the SeChi gene (ADI24346) identified in our laboratory, we constructed the recombinant baculovirus P-Chi for the expression of recombinant SeChi (rSeChi) in Hi5 cells. The rSeChi was purified by chelate affinity chromatography, and the purified protein showed activity comparable with that of a commercial SgChi, suggesting that we harvested active SeChi for the first time. The purified protein was subsequently tested for enzymatic properties and revealed to exhibit its highest activity at pH 8 and 40 C. Using homology modeling and molecular docking techniques, the three-dimensional model of SeChi was constructed and screened for inhibitors. In two rounds of screening, twenty compounds were selected. With the purified rSeChi, we tested each of the twenty compounds for inhibitor activity against rSeChi, and seven compounds showed obvious activity. This study provided new information for the chitinase of beet armyworm and for chitinase inhibitor development.
The present work focuses on the deformation and recovery mechanisms of aged monoclinic U–Nb alloy under tension and load–unload cycle testing using in situ X-ray diffraction (XRD). The U–6.2wt% Nb (U–6.2Nb) alloy was prepared and aged at 200 °C, and then underwent tensile testing followed by the in situ XRD. The experimental results indicate that the change of diffraction peaks can serve to accurately characterize the macroscopic deformation and recovery. Compared with the as-quenched alloy, the aged U–6.2Nb alloy displays different behavior during deformation and subsequent recovery. Phase transformation competes with twin rearrangement to dominate the deformation and recovery between elastic stage and slip stage of the alloy. The lattice plane relationship between α″ and γ° during phase transformation has also been given.
The solid oxide membrane (SOM) electrolysis process has been successfully tested on a laboratory scale to produce silicon directly from silica in a cost-effective and eco-friendly way. A one-end-closed yttria-stabilized zirconia (YSZ) tube was employed to separate a molten salt containing dissolved silica from a liquid metal anode placed inside the YSZ tube. When an applied electric potential between a liquid tin cathode in the molten salt and the anode exceeds the dissociation potential of silica, oxygen ions are transported out of the molten salt through the YSZ membrane and oxidized at the anode while the silicon cations in the flux are reduced to silicon on the surface of the liquid tin cathode. A potentiodynamic scan (PDS) was performed to determine the dissociation potential of silica in the molten salt system. Electrolysis was performed at 1.05 V for 8 hours. The presence of high-purity silicon crystals on the surface of liquid tin cathode was confirmed by scanning electron microscopy (SEM) and electron dispersive X-ray spectroscopy (EDS).
This article presents the findings of a study to investigate the impact perforation resistance of sandwich structures. The dynamic response of sandwich panels based on PVC foam cores has been evaluated by determining the energy to perforate the panels. The impact response of the sandwich structures was predicted using the finite element analysis package Abaqus/Explicit. The validated FE models were also used to investigate the effect of oblique loading and to study the impact response of sandwich panels subjected to a pressure differential equivalent to flying at an altitude of 10,000m.
Low velocity impact testing has shown that the energy to perforate the sandwich panels is dependent on the properties of the core. It has been shown that increasing the density of the crosslinked PVC foams by a factor of two yielded a 600% increase in the perforation resistance of the sandwich structures. At higher densities, the crosslinked foam sandwich structures offered a superior perforation resistance to the linear PVC structures. The numerical analysis accurately predicted the perforation energies of the sandwich panels, as well as the prevailing failure mechanisms following impact. Finally, it has been shown that sandwich panels impacted at high altitude offer a similar perforation resistance to those tested at sea level.
The relationship between recurrent major depression (MD) in women and suicidality is complex. We investigated the extent to which patients who suffered with various forms of suicidal symptomatology can be distinguished from those subjects without such symptoms.
We examined the clinical features of the worst episode in 1970 Han Chinese women with recurrent DSM-IV MD between the ages of 30 and 60 years from across China. Student's t tests, and logistic and multiple logistic regression models were used to determine the association between suicidality and other clinical features of MD.
Suicidal symptomatology is significantly associated with a more severe form of MD, as indexed by both the number of episodes and number of MD symptoms. Patients reporting suicidal thoughts, plans or attempts experienced a significantly greater number of stressful life events. The depressive symptom most strongly associated with lifetime suicide attempt was feelings of worthlessness (odds ratio 4.25, 95% confidence interval 2.9–6.3). Excessive guilt, diminished concentration and impaired decision-making were also significantly associated with a suicide attempt.
This study contributes to the existing literature on risk factors for suicidal symptomatology in depressed women. Identifying specific depressive symptoms and co-morbid psychiatric disorders may help improve the clinical assessment of suicide risk in depressed patients. These findings could be helpful in identifying those who need more intense treatment strategies in order to prevent suicide.
Modeling of free radical polymerizations of the liquid-crystalline monomer 6-[4-(4-heptyloxyphenylazo)phenoxy]hexylacrylate using the PREDICI software package is reported. The model accounts for all elemental reactions that were identified to be important for radical polymerizations of acrylate-type monomers. On the basis of butyl acrylate kinetic data a remarkable agreement between number average molar masses from modelling (Mn,sim) and from experiments (Mn,exp) is observed: Mn,sim = 17800 g·mol−1 and Mn,exp = 17400 g·mol−1. Similarly, dispersity values of 1.8 and 1.6 were determined via modelling and experiments, respectively. It is shown that the assumption of butyl acrylate kinetics provides a reasonable approximation even for acrylate-based monomers having mesogenic substituents.
A zeroth order dendritic carbosilane structure, SiFA4H with four hexafluoroisopropanol (HFIP) functional groups attached via propyl ligand arms to a central silicon atom, has been developed as a model hydrogen-bond (HB) acid sorbent coating and candidate reference HB acid. The HB donor interaction, through the hydroxyl of the HFIP moiety, with a solute HB base can be monitored by observing the hydroxyl stretching frequency through measurements of SiFA4H FTIR spectra before and during vapor exposure. HFIP hydroxyl stretch shifts, upwards of 700 cm-1 have been observed depending on the HB base. For a range of HB bases, the resulting hydroxyl stretch shifts correlate directly with the solute HB basicity scale, “B”, developed by Abraham et al . A variety of techniques exist to measure solute HB basicity, however, the applicability to examine HB bases delivered as vapors or gases and the simplicity of the measurements described herein, with a reusable reference HB acid sorbent coating and standard FTIR spectrophotometer techniques is attractive for some applications including those with hazardous chemicals. Moreover, as an extension of this work we propose employing SiFA4H or related sorbents as molecular sensing coatings, where the semi-selective sorbent is examined by various infrared (IR) spectroscopic techniques to monitor and identify hazardous chemicals, taking advantage of molecular binding phenomena which occur in the sorbent .
Here the synthesis of hydroxy-telechelic four-arm star-shaped oligotetrahydrofuran (4PTHF) with controllable molecular weight was explored, which was perfomed as living cationic ring-opening polymerization of THF using pentaerythritol and trifluoromethanesulfonicanhydride as initiation system. The molecular weights of the 4PTHF were a function of the reaction time. A polymer network was prepared from the hydroxy-telechelic 4PTHF precursor by crosslinking with diisocyanate and the shape-memory properties were determined. High values for Rf and Rr > 98% were obtained even at high programmed elongations, which suggest the 4PTHF-network as a promising shape-memory material. These materials might have a great potential, as the upscaling of synthesis could be successfully demonstrated.
It is well known that there is a linear electro-mechanical coupling under equilibrium thermodynamics in certain crystalline materials with non-centrosymmetric structures. Since Kogan and Meyer published their seminal papers in 1960s[1, 2], people have gradually realized that an inhomogeneous electro-mechanical coupling also exists in insulating materials, which is often called flexoelectricity. The physical mechanism of flexoelectricity in solid crystalline dielectrics is well known and its phenomenological model can be derived from the electromechanical energy coupling under equilibrium thermodynamics, whereas flexoelectricity in liquid crystals is closely related to the geometrical asymmetry of mesogen molecules or the shape polarity but the relation between the flexoelectric coefficients and molecular structures is far from being understood. Theoretically, flexoelectricity in polymers is similar to that in liquid crystals, which is largely dependent on rotation of molecules; therefore, the flexoelectric responses of polymers are complicated and might be different under external perturbations, such as tensile stretching, bending, electric field poling, etc. In this report, we will discuss experimental observations of the giant direct flexoelectric effect in certain polyvinylidene fluoride (PVDF) films under tensile stretching conditions. Our experimental studies indicate that the physical mechanism behind flexoelectricity in polymers might be more complicated than the one proposed for solid crystalline dielectrics.
A triple-shape material based on the two crystallizable segments poly(ω‑pentadeca-lactone) and poly(ε-caprolactone) was synthesized by crosslinking star-shaped precursors. A newly developed programming procedure (TSCP2) was applied in order to achieve triple-shape behavior. The application of this modified triple-shape creation procedure enabled triple-shape capability by influencing the crystallization behavior of the two switching segments in these copolymer networks, which partly show no two distinct and separated melting points. The influence of molecular weight and content of the poly(ε-caprolactone) segment on the triple-shape effect programmed by application of TSCP2 was investigated.
Reflective fibres were obtained in a two step process. First a core polyamide 6 fibre was spun from the melt and successively stretched. Then a chiral nematic liquid crystal coating was applied onto the surface of this fibre and further cured under UV light. The liquid crystal alignment was controlled by the molecular orientation of the polymer fibre and the 10 μm thick mono-domain coating presented a periodic helical organisation with a pitch of 350 nm. The obtained fibre showed strong Bragg reflection giving an intense green colour changing upon viewing angle. The fibre has been integrated into a fabric suggesting its application for textile design, fashion, and apparel.
Aim of this work was to realize free-standing conductive nanofilms having very large surface area with typical nano-scale thickness (40-120 nm) by modifying existing approaches for nanostructured thin films assembly. We tested and optimized two different fabrication methods for the obtainment of free-standing conductive ultra-thin nanosheets based on the conductive polymer poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS). Supporting Layer and Sacrificial Layer techniques permitted the obtainment of single layer nanofilms that can be released in water and of LbL multilayer nanosheets (PEDOT:PSS/Polyelectrolytes) that can be released in acetone, respectively. Here we describe the details of both the proposed fabrication methods and compare the properties of the realized nanosheets in terms of thickness, contact angle and conductivity. Interestingly, the realized free-standing nanosheets, despite their low thickness, are very robust and compliant while maintaining their structure and functionality. Possible applications are foreseen in the field of sensing and actuation, as well as in the biomedical field, e.g. as smart conductive substrates for cell culturing and stimulation.