小型插针类零件的加工工艺研究

小型插针类零件广泛应用于汽车、通信、电子及机床电器等领域,是组成接插件的核心元件之一。中国工程物理研究院电子工程研究所加工生产的插针类零件大多采用H62材质,零件外径尺寸小,长度长,刚性差,工件的尺寸精度和几何精度受加工过程中的切削力、切削热、振动等多种因素影响。针对小型插针类零件加工难度较大、加工质量难以保证等难题,分析了插针类零件的加工难点,并针对零件加工工艺、加工刀具、合理选择切削用量等3个方面合理安排加工顺序和方法,保证了产品加工精度。通过生产实践证明,该加工工艺方法能有效解决小型插针类零件的加工问题,为同类型产品的加工提供了很好的借鉴。

Mechanical Properties of Small-diameter Superfine Silk Powder/Polyurethane Vascular Graft Reinforced by Tubular Knitted Fabric

In this paper,a kind of composite microtube,which is made from superfine silk powder and polyurethane,reinforced by polyster and spandex tubular fabrics,was examined.The cross-section of composite microtubes were microporous,and micropores were uniform distributed,the inner surface was relatively smooth.The results showed that the wall thickness of composite microtubes increased,which led to the strength,the breaking work and the initial modulus incresead;that the spandex content increased brought about the initial modulus and the breaking work decreased,but the breaking extension and the breaking load were firstly increased and then decreased;and all the mechanical properties decreased as the SFSP content increased.

Grape Skin Polyphenols （GSPs） Inhibit the Migration of Mouse Mammary Carcinoma 4T1 Cells in Vitro

OBJECTIVE 1） To study the efficacy of GSPs on the migration of highly metastatic mammary carcinoma cells and 2） To investigate inhibition mechanisms.METHODS Cell migration was assessed using a 24-well transwell assay. Cells with different concentrations of GSPs were suspended （5×105 cell/mL） in RPMI 1640 media in the upper chamber, and RPMI 1640 media with 10% FBS was supplemented in the lower chamber. Then, cells were allowed to migrate for 24 h.RESULTS GSPs inhibited the migration of 4T1 cells in a dosedependent manner. The migration of 4T1 cells was obviously inhibited by GSPs, even at a very low concentration （5 μg/mL）,and was totally inhibited when the concentration was 20 μg/mL.Also, 20 μg/mL of GSPs inhibited cell viability by only 11.4% and induced early apoptosis by only 5.6% compared with a percentage of 4.0% in control cells. GSPs suppressed the activation of PDK1,Akt and Erk1/2 in a dose-dependent manner.CONCLUSION GSPs significantly inhibit the migration of highly metastatic mammary carcinoma 4T1 cells in vitro. This inhibition is independent of decreased cell viability or apoptosis induction. The inhibition of migration by GSPs is involved in blocking the PI3k/Akt and MAPK pathways.

The non-canonical NF-κB pathway promotes NPC2 expression and regulates intracellular cholesterol trafficking

Niemann-Pick type C2(NPC2) is a lysosome luminal protein that functions in concert with NPC1 to mediate egress of lowdensity lipoprotein-derived cholesterol from lysosome. The nuclear factor kappa B subunit 2(NF-κB2) protein is a component of NF-κB transcription factor complex critically implicated in immune and inflammatory responses. Here, we report that NF-κB2 regulates intracellular cholesterol transport by controlling NPC2 expression. RNAi-mediated disruption of NF-κB2, as well as other signaling members of the non-canonical NF-κB pathway, caused intracellular cholesterol accumulation. Blockage of the non-canonical NF-κB pathway suppressed NPC2 expression, whereas Lymphotoxin β receptor(LTβR) activation or Baff receptor(BaffR) stimulation up-regulated the mRNA abundance and protein level of NPC2. Further, NF-κB2 activated NPC2 transcription through direct binding to its promoter region. We also observed cholesterol accumulation in NF-κB2-deficient zebrafish embryo and NF-κB2 mutant mice. Collectively, these data identify a regulatory role for the non-canonical NF-κB pathway in intracellular cholesterol trafficking and suggest a link between cholesterol transport and immune system.

The Regulation of cGAS

The cGAS-MITA pathway of cytosolic DNA sensing plays essential roles in immune response against pathogens that contain DNA or with DNA production in their life cycles. The cGAS-MITA pathway also detects leaked or aberrant accumulated self DNA in the cytoplasm under certain pathological conditions, such as virus induced cell death, DNA damage, mitochondria damage, gene mutations, which results in autoimmune diseases. Therefore, the cGAS-MITA pathway must be tightly controlled to ensure proper immune response against pathogens and to avoid autoimmune diseases. The regulation of cGAS-MITA pathway at MITA-level have been extensively explored and reviewed elsewhere,here we provide a summary and perspective on recent advances in understanding of the cGAS regulation.

Effects of Xinfeng capsule on the Fas/FasL-mediated apoptotic pathway in patients with rheumatoid arthritis

OBJECTIVE:To observe the effects of Xinfeng capsule on the apoptosis of peripheral blood CD4+ T lymphocytes and changes in the Fas/Fas L-mediated apoptotic pathway in patients with rheumatoid arthritis(RA).METHODS:A total of 28 RA patients were included in the study;they were randomly divided into the Xinfeng capsule(XFC) group(3 capsules,3 per day)and the leflunomide(LEF) group(1 pellet,once per night).The treatment course in each groups was 12 weeks.The normal control(NC) group consisted of10 healthy people.The apoptotic rate was examined using flow cytometry.Fas,Fas L,caspase 8,caspase 3,bcl-2,and bax m RNA were examined using q RT-PCR.Apoptotic proteins Fas,Fas L,caspase8,and caspase 3 were examined using western blotting.RESULTS:After treatment,patients in the two groups all showed some trend of improvement.Disease activity indexes,joint morning stiffness time,joint swelling/tenderness number,health assessment questionnaire(HAQ) score,RA quality of life(RAQOL) questionnaire,and self-rating anxiety scale(SAS),as well as all apoptotic related indicators were reduced in both groups after treatment with no significant difference between groups.But the improvement in terms of the self-rating depression scale(SDS) in the XFC group was better than in the LEF group.RA patients showed lower apoptotic rates in CD4+ T cells,lower bax,Fas,caspase 8,and caspase 3 m RNA,and less protein expression of Fas,caspase 8,and caspase3 than in the NC group.These indicators increased after treatment.However,the level of Bcl-2 m RNA was higher in the XFC group than in the NC group before treatment,and it subsequently decreased.The XFC group expressed lower Bcl-2 m RNA than the LEF group.Negative correlations were found between ESR and the apoptotic rate in CD4 + T cells,Fas,and caspase 3;CRP and Fas;and,swollen joint count and Bax,while positive correlations were found between ESR and Bcl-2.CONCLUSION:XFC can regulate the Fas/Fas L system and promote CD4+ T cell apoptosis and thus reduce the abnormal immune response,which can improve symptoms in RA patients.