Effect of Repetitive Bending and Straightening Process on Microstructure Properties and Deformation Mechanism of a Ti-Al-Cr-Mo Alloy.

In this research, a repetitive bending and straightening process was carried out on the Ti-3Al-4Cr-Mo alloy for 20 passes. The changes in mechanical properties of the titanium alloy before and after repetitive bending and annealing were studied. The microstructure evolution and deformation mechanism were analyzed. The results show that after the repetitive bending and straightening process, the microstructure of the Ti-3Al-4Cr-Mo alloy is obviously refined, and, simultaneously, the yield strength is significantly improved. After annealing at 850 °C, the plastic ductility of the material was improved. The combined effects of grain refinement and dislocation behavior were the main reasons for the improvement in mechanical properties of the Ti-3Al-4Cr-Mo alloy. Twinning rarely occurred during plastic deformation of the Ti-3Al-4Cr-Mo alloy. The fine grains strongly inhibited the formation of twins. In addition, a small amount of α to ß phase transformation was observed during the repetitive bending and straightening process of the material, which may have been induced by strain accumulation.

Zona incerta subpopulations differentially encode and modulate anxiety.

Despite recent clinical observations linking the zona incerta (ZI) to anxiety, little is known about whether and how the ZI processes anxiety. Here, we subject mice to anxious experiences and observe an increase in ZI c-fos­labeled neurons and single-cell calcium activity as well as an efficient effect of ZI infusion of diazepam, a classical anxiolytic drug. We further identify that somatostatin (SOM)­, calretinin (CR)­, and vesicular glutamate transporter-2 (Vglut2)­expressing cells display unique electrophysiological profiles; however, they similarly respond to anxiety-provoking stimuli and to diazepam. Optogenetic manipulations reveal that each of these ZI neuronal populations triggers specific anxiety-related behavioral phenotypes. Activation of SOM-expressing neurons induced anxiety, while photoactivation of CR-positive cells and photoinhibition of Vglut2-expressing neurons produce anxiolysis. Furthermore, activation of CR- and Vglut2-positive cells provokes rearing and jumps, respectively. Our findings provide the first experimental evidence that ZI subpopulations encode and modulate different components of anxiety.

Lateral ventral tegmental area GABAergic and glutamatergic modulation of conditioned learning.

The firing activity of dorso-medial-striatal-cholinergic interneurons (dmCINs) is a neural correlate of classical conditioning. Tonically active, they pause in response to salient stimuli, mediating acquisition of predictive cues/outcome associations. Cortical and thalamic inputs are typical of the rather limited knowledge about underlying circuitry contributing to this function. Here, we dissect the midbrain GABA and glutamate-to-dmCIN pathways and evaluate how they influence conditioned behavior. We report that midbrain neurons discriminate auditory cues and encode the association of a predictive stimulus with a footshock. Furthermore, GABA and glutamate cells form selective monosynaptic contacts onto dmCINs and di-synaptic ones via the parafascicular thalamus. Pathway-specific inhibition of each sub-circuit produces differential impairments of fear-conditioned learning. Finally, Vglut2-expressing cells discriminate between CSs although Vgat-positive neurons associate the predictive cue with the outcome. Overall, these data suggest that each component of the network carries information pertinent to sub-domains of the behavioral strategy.

A Key Role for Prefrontocortical Small Conductance Calcium-Activated Potassium Channels in Stress Adaptation and Rapid Antidepressant Response.

The muscarinic acetylcholine receptor antagonist scopolamine elicits rapid antidepressant activity, but its underlying mechanism is not fully understood. In a chronic stress model, a single low-dose administration of scopolamine reversed depressive-like reactivity. This antidepressant-like effect was mediated via a muscarinic M1 receptor-SKC pathway because it was mimicked by intra-medial prefrontal cortex (intra-mPFC) infusions of scopolamine, of the M1 antagonist pirenzepine or of the SKC antagonist apamin, but not by the selective serotonin reuptake inhibitor (SSRI) antidepressant fluoxetine. Extracellular and whole-cell recordings revealed that scopolamine and ketamine attenuate the SKC-mediated action potential hyperpolarization current and rapidly enhance mPFC neuronal excitability within the therapeutically relevant time window. The SKC agonist 1-EBIO abrogated scopolamine-induced antidepressant activity at a dose that completely suppressed burst firing activity. Scopolamine also induced a slow-onset activation of raphe serotonergic neurons, which in turn was dependent on mPFC-induced neuroplasticity or excitatory input, since mPFC transection abolished this effect. These early behavioral and mPFC activational effects of scopolamine did not appear to depend on prefrontocortical brain-derived neurotrophic factor and serotonin-1A activity, classically linked to SSRIs, and suggest a novel mechanism associated with antidepressant response onset through SKC-mediated regulation of activity-dependent plasticity.

Rostrocaudal subregions of the ventral tegmental area are differentially impacted by chronic stress.

RATIONALE: The ventral tegmental area (VTA) is implicated in the pathophysiology of depression and addictive disorders and is subject to the detrimental effects of stress. Chronic stress may differentially alter the activity pattern of its different subregions along the rostrocaudal and dorsoventral axes, which may relate to the variable behavioral sensitivity to stress mediated by these subregions. OBJECTIVES: Here, chronic stress-exposed rats were tested for depressive-like reactivity. In situ hybridization for zif268 as a marker of neuronal activation was combined with in vivo single-unit recording of dopaminergic neurons to assess modifications in the activity of the rostral VTA (rVTA) and caudal VTA (cVTA). Changes in the expression of stress-responsive glucocorticoid receptors (GR) and brain-derived neurotrophic factor (BDNF) were also assessed. RESULTS: Stress-induced anhedonia-like, hyper-anxious, and passive-like responding were associated with reductions in dopaminergic burst activity in the cVTA and an increase in local GABAergic activity, particularly in GABAA receptor sensitivity. On the other hand, stress increased single-spiking activity, burst activity, and zif268 mRNA levels in the rVTA, which were associated with increased glutamatergic tonus and enhanced GR and AMPA receptor (AMPAR) expression. rVTA and cVTA activity differentially correlated with sucrose preference and passivity measures. CONCLUSIONS: These data demonstrate that the rVTA and cVTA respond differently to stress and suggest that while cVTA activity may be related to passivity-like states, the activity of both subregions appears to be related to anhedonia and the processing of incentive value. These region-dependent abnormalities indicate the multi-modular composition of the VTA, which could provide multiple substrates for different symptom features.

[Construction and expression of non-fusional expression vector of the multi-epitope gene of hepatitis B virus].

AIM: To study the cloning, expression and antigen of therapeutic multi-epitope gene of hepatitis B virus. METHODS: The multi-epitope gene of hepatitis B virus(BPT) was designed, synthesized and cloned into the prokaryotic expression vector pBAD/gIIIA. Then it was transformed into E.coli Top10 and multi-epitope protein of hepatitis B virus(B-BPT) was expressed under the induction of Arabinose. The immunogenicity of the protein was analyzed by Western blot detection. RESULTS: The recombinant plasmid pBAD/BPT was constructed successfully and the protein of multi-epitope gene of hepatitis B virus was expressed in E.coli. Western blot detection showed the protein had ideal antigenicity. CONCLUSION: The design of therapeutic multi-epitope gene of hepatitis B virus is proved to be correct. The expressed protein may be a good therapeutic vaccine.

[Effect of HBsAg pulsed dendritic cells on the functions of cytokine-induced killer cells].

AIM: To explore the effects of HBsAg-pulsed dendritic cells (DCs) on the proliferation and killing functions of cytokine-induced killer (CIK) cells. METHODS: The peripheral blood mononuclear cells (PBMCs) were isolated from the patients with chronic hepatitis B by the routine method, and induced into specific DCs with HBsAg pulsed. The (3)H-TdR incorporation method was used to determine the stimulation effect of HBsAg-pulsed DCs on the proliferation of CIK cells. LDH release assay was used to measure the specific killing activity of CIK cells on HepG2215 cells. RESULTS: The HBsAg-pulsed DCs could induce the memory proliferation of CIK cells and strengthen the killing activity of CIK cells (P<0.05). CONCLUSION: HBsAg-pulsed DCs can enhance the proliferation and killing functions of CIK cells.

[Retrospective analysis on clinical features of 35 patients with severe acute respiratory syndrome].

OBJECTIVE: To analyze the clinical features of severe acute respiratory syndrome (SARS). METHODS: The clinical features of 35 patients with SARS in the past five months were retrospectively studied, and compared with 35 patients with community-acquired pneumonia. Consecutive blood samples from 13 patients with SARS and 10 healthy volunteers were collected. The CD+4 and CD+8 in T cell in peripheral blood were detected by flow cytometry. RESULTS: The most common symptoms included fever (in 100.0 percent of the patients), cough (74.3 percent), headache (45.7 percent), myalgia (45.7 percent) and lymphopenia (20/33). Serial chest radiographs showed progressive multi-infiltration in the lung fields. The CD+4 and CD+8 in T cell in 13 patients with SARS significantly decreased [CD+4: (16.10+/-4.31) percent vs. (38.30+/-8.52) percent, t=8.174,P<0.01; CD+8: (19.90+/-5.40) percent vs. (28.38+/-4.33) percent, t=4.055, P<0.01]. The time of bringing down the fever and the time of absorption of pathological changes in SARS patients were prolonged than those of the pneumonia patients [the time of bringing down the fever (13.92+/-8.35) days vs. (3.86+/-1.42)days, t=16.490,P=0.000;the time of absorption of pathological changes: (11.97+/-4.41) days vs. (9.21+/-4.42) days, t=3.082,P=0.003]. CONCLUSION: SARS is a serious respiratory illness, the most common symptoms are fever, cough, headache and myalgia, other common findings are lymphopenia, the CD+4 and CD+8 in T cell in peripheral blood decrease and multi-infiltrate through out the lung fields.