Effects of Processing Parameters on the Microstructure and Mechanical Properties of Nanoscaled WC-10Co Cemented Carbide

This work was mainly focused on the processing-parameter-related microstructure and properties of ultrafine WC-10Co-0.4VC-0.5Cr₃C₂ cemented carbide. The samples were prepared via a spark plasma sintering (SPS) technique using nano WC and Co powders and the corresponding inhibitor VC and Cr₃C₂ powders. The influence of the processing process on the microstructure and mechanical properties of ultrafine-grained cemented carbide was investigated under different ball-milling times and sintering temperatures. The results showed that the grain size of WC decreased with increasing ball-milling time and decreasing sintering temperature and that the specific gravity of ε-Co increased with increasing ball-milling time. The hardness of cemented carbide increased with increasing ball-milling time and decreased with increasing sintering temperature due to the corresponding variation in grain size and the relative density of samples. The transverse fracture strength (TRS) was mainly affected by ball-milling time. The increase in ball-milling time led to decreased TRS values, mainly ascribed to the formation of WC particle agglomeration and the decreased WC-Co eutectic temperature. In addition, temperature changes were found to have little effect on TRS. The samples sintered at 1250 °C with a ball-milling time of 60 h had comprehensive mechanical properties. Their average grain size, relative density, hardness, and TRS were 355.5 nm, 95.79%, 2035.5 kg/mm², and 2155.99 MPa, respectively.     

Trappin-2对HaCaT细胞及银屑病跨膜模型增殖的抑制作用

目的 构建Trappin-2的真核表达体系,初步探讨Trappin-2对HaCaT细胞及银屑病跨膜模型增殖的影响.方法 采用DNA重组技术构建Trappin-2的表达载体pIRES2-EGFP-Trappin-2,通过脂质体法转染入宫颈癌HeLa细胞.将Trappin-2高表达上清加入HaCaT细胞及银屑病跨膜模型中,通过3H-TdR掺入法、MTT法、流式细胞术及组化染色Ki67检测对增殖的影响.结果 Trappin-2作用后MTY和cpm值变化率显示Trappin-2可抑制HaCaT细胞的代谢与DNA合成,同时可使HaCaT细胞G2 S期细胞比例下降,而G1期细胞比例增加.Trappin-2可下调银屑病皮损Ki67表达水平.结论 成功将Trappin-2基因转染HeLa细胞,并进行有效表达,初步证实Trappin-2具有抑制HaCaT细胞及银屑病跨膜模型增殖的特性.     

新型便携式输液控制器的环境适应性研究

目的 评估一种新研发的便携式输液控制器的环境适应性。方法 收集2020年12月至2021年3月在相同研究者及研究环境下的新型便携式输液控制器（实验组）和传统输液控制器（对照组）环境适应性数据,通过体外模拟左右、上下晃动以及实景模拟行走、上下楼梯、外出检查、上卫生间、院前急救、战地转运评估两组在报警/停机指标方面的环境适应性。每种环境重复观察100次。结果 在体外模拟晃动干扰时,实验组在左右晃动时的可晃动度数为（32.42±4.27）°,高于对照组的（15.36±5.58）°,差异有统计学意义（P<0.05）;实验组在上下晃动时的可拉升倍数为（1.33±0.08）倍,高于对照组的（1.16±0.05）倍,差异有统计学意义（P<0.05）;在实景模拟实验中,实验组在所有运行情景中的报警/停机率均低于对照组,差异有统计学意义（P<0.05）。在模拟极慢速行走、慢速行走、上下楼梯、外出检查、上卫生间、救护车正常行驶、战地担架转运等场景时,实验组的报警/停机率为0%,可达到对环境完全适应;而对照组在以上环境下均会发生不同程度的报警/停机。结论 新型便携式输液控制器不但具有控制精...     

胰头肿块型慢性胰腺炎12例诊治分析

目的分析胰头肿块型胰腺炎的诊治方法。方法回顾性分析我院1998年6月至2008年6月间收治的125例慢性胰腺炎病例,总结其中12例因胰头占位而行胰十二指肠切除术患者的病例。结果12例患者术中探查均显示肿块位于胰头,与周围组织有粘连,其中1例与门静脉有粘连,但尚能剥离,术后病理证实均为慢性胰腺炎。结论目前区分慢性胰腺炎与胰腺癌尚无特异性好和敏感性高的鉴别方法,CT结合经内镜逆行胰胆管造影对大部分病例的鉴别诊断具有较高的价值,胰头肿块型胰腺炎行胰头十二指肠切除术治疗效果良好。     

头颈肿瘤组织标本库构建的初步研究

目的 探讨头颈肿瘤组织标本的采集、保存,组织库构建方法,以及信息化管理技术。方法 收集手术切除和活检的头颈肿瘤组织、癌旁组织、远端正常组织及患者和正常人外周血标本(分离出血清、血浆、淋巴细胞、干细胞等),置于液氮或-80℃低温冰箱冷冻保存;同时建立一套系统管理组织标本库,使标本库规模化、信息化、智能化。结果 共收集新鲜组织标本220份,血液标本476份。其中肿瘤组织120份(包括肿瘤组织、癌旁组织);非肿瘤组织100份。肿瘤患者血液标本316份,非肿瘤患者血液标本160份。结论 标本库的建立使少见的头颈肿瘤组织标本集约化、规模化,极大提高了标本利用的效率,达到了资源共享的目的。     

地塞米松和组胺对人鼻息肉组织黏蛋白MUC5AC mRNA和蛋白表达的影响

目的:研究地塞米松和组胺对培养的人鼻息肉组织黏蛋白MUC5AC mRNA和蛋白表达的影响。方法:实验分为对照组、组胺刺激组和地塞米松干预组,采用RT-PCR和免疫组织化学技术分别检测鼻息肉组织中MUC5AC mRNA和蛋白的表达。结果:组胺刺激组鼻息肉组织MUC5AC mRNA和蛋白表达分别为0.6389±0.0526和0.1934±0.0137,均较对照组(分别为0.3495±0.0357和0.1172±0.0173)明显增加(均P<0.01),地塞米松抑制后两者均明显降低(分别为0.4988±0.0603和0.1444±0.0075)(均P<0.05)。结论:炎性递质组胺可上调黏蛋白表达;地塞米松可下调黏蛋白表达,这可能是它抑制鼻息肉黏液过度分泌的途径之一。     

Hippo pathway monomerizes STAT3 to regulate prostate cancer growth

Prostate cancer ranks among the most commonly diagnosed malignancies for men and has become a non‐negligible threat for public health. Interplay between inflammatory factors and cancer cells renders inflammatory tissue environment as a predisposing condition for cancer development. The Hippo pathway is a conserved signaling pathway across multiple species during evolution that regulates tissue homeostasis and organ development. Nevertheless, whether Hippo pathway regulates cancer‐related inflammatory factors remains elusive. Here, we show that high cell density–mediated activation of the Hippo pathway blunts STAT3 activity in prostate cancer cells. Hippo pathway component MST2 kinase phosphorylates STAT3 at T622, which is located in the SH2 domain of STAT3. This phosphorylation blocks the SH2 domain in one STAT3 molecule to bind with the phosphorylated Y705 site in another STAT3 molecule, which further counteracts IL6‐induced STAT3 dimerization and activation. Expression of a nonphosphorylatable STAT3 T622A mutant enhances STAT3 activity and IL6 expression at high cell density and promotes tumor growth in a mice xenograft model. Our findings demonstrate that STAT3 is a novel phosphorylation substrate for MST2 and thereby highlight a regulatory cascade underlying the crosstalk between inflammation and the Hippo pathway in prostate cancer cells.     

周细胞的研究进展

周细胞是一种多能细胞,可以向骨、软骨等组织分化;具有收缩能力,从而调节微环境的灌流量和通透性;还能和内皮细胞相互作用,参与血管形成和创伤愈合。周细胞的功能失调和许多微血管疾病以及肿瘤的扩散相关。一直以来,对周细胞的存在以及功能有所忽略,最近才对其有一定的认识。本文就周细胞的定位、结构、标记物、功能、相关的信号通路以及在肿瘤中所起的作用做一简单的介绍。     

后路单节段固定结合单枚Cage周围植骨治疗腰椎滑脱症48例

目的:观察采用后路单节段固定结合单枚Cage周围植骨治疗腰椎滑脱症的疗效。方法:采用后路单节段固定结合单枚Cage周围植骨治疗腰椎滑脱症48例,观察植骨融合时间及术后优良率。结果:48例中有46例获得11~30个月随访。术后4~9个月植骨融合;坚强融合43例,可能融合2例,未融合1例,植骨融合率为97.83%。术后疗效优25例,良19例,可2例,差0例,优良率95.65%。结论:后路单节段固定结合单枚Cage周围植骨治疗腰椎滑脱能较好地复位和固定,脊柱融合率高,临床效果满意。     

颅内血肿体积个人计算机测量方法

目的:研究个人计算机测量法对颅内血肿体积测量的价值.方法:40例不同类型的颅内血肿分别使用CT定量软件及个人计算机Photoshop CS3 Extented软件测量其体积,分析不同方法的测量结果是否具有统计学意义.结果:个人计算机测量法与CT定量法所测颅内血肿体积差异无统计学意义(P＞0.05).结论:个人计算机测量...