原位合成Cr掺杂的SnO_(2)纳米墙及其乙炔气敏性能研究

为了解决纯SnO_(2)基气体传感器对乙炔(C_(2)H_(2))工作温度高的难题,采用水热法对原位生长的SnO_(2)纳米墙进行不同摩尔比的金属铬(Cr)元素掺杂,研究了Cr掺杂对SnO_(2)纳米墙的形貌结构与气敏性能的影响。研究结果表明:当掺杂摩尔分数x(Cr)=3%时,制备的SnO_(2)纳米墙垂直于衬底方向定向生长,纳米片相互交联形成了三维立体多孔网络结构,为气体的吸附提供了活性位点和传输通道;与纯SnO_(2)纳米墙相比,掺杂摩尔分数x(Cr)=3%制备的SnO_(2)基气体传感器在检测质量分数w为2×10^(-4)的C_(2)H_(2)时,最佳工作温度由175℃降至125℃,响应值高达8.1,检测极限低至1×10^(-6),响应和恢复时间分别为165 s和80 s。结论可为研究低工作温度的C_(2)H_(2)传感器的制备及应用提供参考。

乡村振兴背景下的乡村发展潜力评估、分类与规划引导

在快速城镇化发展的过程中,乡村发展潜力是衡量一个地区乡村振兴发展能力的重要指标。文章从增强乡村振兴吸引点和满足乡村振兴目标出发,从内生潜能和外部赋能角度分析了影响乡村发展的5个潜力要素,以此构建了由“目标分类要素指标”构成的多层次乡村发展潜力评估指标体系。在此基础上,以山东省东阿县为例,通过GIS叠加分析技术探索其乡村发展潜力单项评估和综合评估水平,并依据评估结果和地缘特征划分乡村振兴发展的类型,提出不同类型的规划引导建议。

英夫利西单抗联合肠内营养在中重度溃疡性结肠炎治疗中的临床价值

目的:观察英夫利西单抗联合肠内营养(EN)为主的治疗方法对中重度溃疡性结肠炎(UC)患者的临床疗效。方法:收集20例传统治疗无效的中重度UC患者,予英夫利西单抗5 mg/kg的剂量静脉微泵输注一个疗程(共6次)联合EN治疗3个月,并口服硫唑嘌呤进行维持治疗。结果:经治疗后UC患者的BMI、Hb、ALB均较治疗前明显升高(P<0.05);UC改良的Mayo评分、CRP、ESR、WBC均较治疗前明显降低(P<0.05);16例UC患者治疗有效,其中15例患者达到临床缓解,12患者达到黏膜愈合。随访6~24个月,其中1例患者发生恶性淋巴瘤,1例患者自行停服硫唑嘌呤后病情复发,其余患者病情控制良好未复发。结论:英夫利西单抗联合EN为主诱导UC患者临床缓解、并予硫唑嘌呤维持UC患者临床缓解的方法对于中重度UC患者具有良好的临床疗效,可以改善患者的预后。

Ag修饰ZnO纳米墙的光敏特性研究

为了开发对紫外(UV)光响应更好的光敏传感材料,文中采用水溶液法、醇还原法和悬涂法构筑了ZnO/Ag复合材料,通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)和能谱仪(EDS)对其进行表征,采用光敏测试分析系统对其光敏性能进行测试。研究结果表明:纳米Ag均匀地覆盖在ZnO纳米墙的表面,其分布率为23.53%。在室温下,ZnO/Ag复合材料对紫外(UV)光的灵敏度为426,其响应时间和恢复时间分别为9 s和43 s,并且具有良好的选择性和稳定性。ZnO/Ag复合材料光敏性能的增强是基于费米能级的转变和电子和光生载流子的转移速度和数量提升。

SiC增强铝基复合材料电加工性能研究

为研究电火花线切割电参数对加工SiC增强铝基复合材料加工过程的影响.文中通过加工实验,分析了电火花线切割电参数对加工SiC增强铝基复合材料加工效率和表面粗糙度的影响,表征了加工表面形貌.实验结果表明:电火花线切割加工5%SiC颗粒增强铝基复合材料,脉宽小于15μs时,加工效率随着脉宽的增加而提高;当脉宽增加至15μs时,其加工效率达最大值134.64mm^2·min^(-1),脉宽继续增加,加工效率下降.表面粗糙度随着脉宽的增加而增加;随着脉间的增加,加工效率急剧下降后趋于平缓,脉间增至25μs后,加工效率继续降低但变化不大.表面粗糙度随脉间增加在3.58~4.69μm之间无规律变化.随着峰值电流增加,加工效率及表面粗糙度呈线性增大.加工效率及表面粗糙度值随伺服电压的增加而降低.

The Stability Analysis of Implants Installed in Osteotomies with Different Types of Controlled Bone Defects

The stability parameters of implants （ITV, ISQ ＆ PTV） according to different sizes of controlled bone defects made in implant osteotomies were analyzed and the correlation among the three kinds of implant stability parameters was tested in this study. 45 tapped screw-type dental implants were inserted in three types of implant osteotomies made in 8 fresh-frozen pig femoral bones： Typel - without coronal bone defect, Type2 - with 3 mm coronal bone defects, and Type3 - with 6 mm coronal bone defects. The insertion torque values, ISQ ＆ PTV of implants were measured and analyzed statistically. It is concluded that the circumferential coronal bone defects statistically influence the primary stability of implants; ITV, ISQ and PTV are suitable and available to detect the peri-implant coronal bone defects in 3 mm increments, and ITV and PTV are more sensitive to coronal cortical bone loss. There was a strong correlation between ITV and ISQ.

Surface Characteristics of Mussel-inspired Polydopamine Coating on Titanium Substrates

Mussel adhesive proteins are non-toxic, biodegradable and have low immunogenic qualities that make them highly attractive for medical purposes compared with man-made materials. 3,4-DOPA, which is a dopamine precursor, is a critical element for achieving mussel-like adhesive properties. In present study, polydopamine was coated onto the titanium surfaces by dipping in a 2 mg/mL dopamine solution in 10 mM Tris- HCl buffer at pH 8.5. EDX element analysis and Raman spectroscopic analysis of the surface were conducted to verify the formation of polydopamine. The surface characteristics of polydopamine-coated titanium plates were observed by SEM and AFM. Hydrophilicity and corrosion-resistance were also evaluated by static contact angle measurements and potentiodynamic polarization corrosion tests. The absorption intensity for pH-induced polymerization rapidly increased for the initial four hours and thereafter smoothly increased. EDX element analyses revealed that the content of carbon and oxygen increased and the content of titanium decreased after the coating process. In the Raman spectra, polydopamine resulted in two new peaks at approximately 1 370 and 1 570 cm^-1 resulting from the stretching and deformation of catechol. Microstructural features revealed that nanometer-sized bright granules were randomly distributed after coating, and these nanoparticles grew with increased coating time. The Ra values of polydopamine-coated titanium plates were showed to increase with coating time. Compared to the pure titanium curve, the inflection point of polydopamine-coated titanium was located at a higher corrosion potential and lower corrosion current density. Findings from our research suggested that polydopamine coatings offer a versatile approach for titanium surface modification.

肿瘤坏死因子超家族成员15基因多态性与溃疡性结肠炎的关系

目的 在浙江籍汉族人群中探讨肿瘤坏死因子超家族成员（TNFSF）15基因多态性及单倍型与溃疡性结肠炎（UC）易感性的关系。方法 收集408例UC患者和574名性别、年龄相匹配的健康对照者，采用＂改良多重高温连接酶检测反应技术（iMLDR）＂检测TNFSF15基因3个单核苷酸多态性（SNP）位点（rs3810936、rs4263839、rs4979462），并进行连锁不平衡和单倍型分析。结果 UC组中rs4263839的变异等位基因A和基因型（GA＋AA）频率均低于对照组（45.34%比50.17%，P=0.035；68.38%比76.66%，P=0.004）。依据UC严重程度和疾病部位进一步分层分析，经多重比较校正检验水准（α=0.012 5），结果发现重度结肠炎患者中rs4263839的变异等位基因A和基因型（GA＋AA）频率低于对照组（37.69%比50.17%，P=0.007；60.00%比76.66%，P=0.004）；广泛性结肠炎患者中rs4263839的变异等位基因A和基因型（GA＋AA）频率亦低于对照组（42.22%比50.17%，P=0.009；63.33%比76.66%，P〈0.001）。Haploview 4.2软件分析发现，rs3810936、rs4263839和rs4979462彼此紧密连锁，所构建的单倍型TAC在UC组中的频率低于对照组（40.83%比46.04%，P=0.023）；并且与对照组相比，重度结肠炎患者和广泛性结肠炎患者中，单倍型TAC的频率均显著降低（33.38%比46.04%，P=0.005；37.22%比46.04%，P=0.003）。结论 TNFSF15基因rs4263839位点变异不仅可能降低UC的发病风险，还可能影响UC严重程度和疾病部位。由rs3810936、rs4263839和rs4979462构建的单倍型TAC可能降低UC，尤其是重度结肠炎和广泛性结肠炎的发病风险。