Characterization of Al2O3 Matrix Composites Fabricated via the Slip Casting Method Using NiAl-Al2O3 Composite Powder

This work aimed to characterize Al₂O₃ matrix composites fabricated by the slip casting method using NiAl-Al₂O₃ composite powder as the initial powder. The composite powder, consisting of NiAl + 30 wt.% Al₂O₃, was obtained by mechanical alloying of Al₂O₃, Al, and Ni powders. The composite powder was added to the Al₂O₃ powder to prepare the final powder for the slip casting method. The stained composite samples presented high density. EDX and XRD analyses showed that the sintering process of the samples in an air atmosphere caused the formation of the NiAl₂O₄ spinel phase. Finally, the phase composition of the composites changed from the initial phases of Al₂O₃ and NiAl to Al₂O₃, Ni, and NiAl₂O₄. However, in the area of Ni, fine Al₂O₃ particles remaining from the initial composite powder were visible. It can be concluded that after slip casting, after starting with Al₂O₃ and the composite powder (NiAl-Al₂O₃) and upon sintering in air, ceramic matrix composites with Ni and NiAl₂O₄ phases, complex structures, high-quality sintered samples, and favorable mechanical properties were obtained.     

逆锁键调控野生型和功能增强型ADAMTS13与VWF A2结构域的相互作用

目的 探究瞬时接触时间下野生型(wild-type, WT)和功能增强型(gain-of-function, GOF)金属蛋白酶ADAMTS13与VWF A2结构域的相互作用,阐明其动力学调控的分子机制。方法 利用原子力显微镜测量在不同外力作用下WT和GOF ADAMTS13分子与VWF A2的黏附频率、断裂力和分子键寿命,并利用Bell-Evans模型提取相关动力学参数。结果 WT ADAMTS13与VWF A2结合的能障宽度为0.41 nm, 0 N力下的解离速率为1.50 s^-1;GOF ADAMTS13与VWF A2结合的能障宽度为0.29 nm, 0 N力下的解离速率为3.28 s^-1。进一步利用AFM clamp模式测量在不同作用力下WT/GOF ADAMTS13-VWF A2复合物的分子键生存寿命和解离速率,发现两组复合物的结合均呈现“逆锁键”-“滑移键”转换的双相力学依赖特性。结论 WT ADAMTS13-VWF A2相互作用的机械强度与力学稳定性高于GOF ADAMTS13-VWF A2,WT/GOF ADAMTS13与VW...     

金黄色葡萄球菌快速检验测试片在食品检验中的应用

目的建立一种适宜快速检测食品中金黄色葡萄球菌的方法。方法采用金黄色葡萄球菌测试片检验食品中的金黄色葡萄球菌，并用国标法进行对比。结果测试片法检验金黄色葡萄球菌特异高，最小检出量1．1×10^-4cfu／g（rrd），敏感度为3．0×10^-8cfu／g（m1），比国标法可提高3个指数的最小检出量。通过对242份食品的检测对照，测试片法阳性检出率为31．40％，国标法阳性检出率23．97％，阳性检出率可提高7．50％。结论测试片法操作简单，方便快捷，结果易观察，准确可靠，抑制杂菌能力强，工作周期短。     

副溶血性弧菌快速测试片检测性能研究

目的:对副溶血性弧菌快速测试片的检测性能进行测试研究。方法:以副溶血性弧菌、霍乱弧菌、溶藻弧菌等49株标准和参考菌株检测测试片的敏感性、特异性和可重复性。结果:该测试片对纯菌的检测灵敏度达到8 cfu/m l;与霍乱弧菌等17种非目的菌无交叉反应;重复性试验结果相对偏差低于8%;24 h可完成检验工作。应用该测试片检测人工染菌样品和自然样品,检测结果与GB或SN标准方法一致。结论:副溶血性弧菌快速测试片具有敏感度高、特异性强、重复性好、操作简便等优点,可用于食品和水产品中副溶血性弧菌的快速初筛。     

微生物快速测定卡凝胶剂性能初步研究

目的:从吸水吸盐量、抑菌性、微生物可分解利用性、菌落生长等方面初步考察高吸水性树脂聚丙烯酸钠是否可用作微生物快速鉴定卡的凝胶剂。方法:吸水吸盐量测定采用过筛法,抑菌性采用16种菌株进行测试,聚丙烯酸钠微生物可分解利用性和菌落生长情况用7种代表菌株进行。结果:聚丙烯酸钠的吸水量414.1±15.2 g/g,吸生理盐水(9 g/LNaCl)46.65±4.01 g/g;对16种菌株测试均无抑制作用出现;微生物不能以聚丙烯酸钠为唯一碳源生长;在聚丙烯酸钠载体上,微生物可以长出单菌落且数量和琼脂平板在统计学上无显著差异。结论:聚丙烯酸钠可以用作快速测试片的凝胶剂。     

超声诊断近端指间关节伸指肌中央腱断裂的临床研究

目的 从临床上评价超声检查对诊断近端指间关节伸指肌中央腱断裂的准确性.方法 67名近端指间关节受伤的病人接受了超声检查.超声采用5～10MHz实时线性变曲探头.并采用了3种临床体格联合检查方法,对伤情进行了判断.以手术探查结果为标准,对超声检查结果和临床体格检查结果进行了比较.结果 手术探查结果证实39名病人有伸指肌中央腱断裂.超声检查结果与手术探查结果有非常好的一致性.超声检查和临床体格检查的敏感性分别为100%和89.74%,特异性为96.4%和8.14%.两种检查方法经统计学处理有显著差异(P<0.01).结论 超声检查是一种非侵入性早期准确诊断近端指间关节伸指肌中央腱断裂的方法.     

自制一次性防滑中单

在临床上,一次性中单已广泛使用。对于术后有切口或切口有渗出液及卧床患者,为避免污染床单元,保持床单位清洁干燥,使患者舒适,一次性中单非常适用。但由于现在的一次性中单没有足够长度掖在床垫下面,患者在使用时,极易滑向其它位置;有时患者翻身活动时,揉作一团,没有起到中单的作用,既浪费了材料,又增加了护理量,患者也极不舒适。     

Central slip tenotomy for chronic mallet finger

We performed a retrospective audit of a consecutive series of twenty-three patients to evaluate the results of central slip tenotomy performed for chronic mallet finger. The surgery was performed at a mean of 42 (range four to 480) months after surgery and the pre-operative extensor lag at the distal interphalangeal joint was a mean of 44 (range 20–80) degrees. At the time of evaluation, at a mean of 33 (range six to 95) months after surgery, the extensor lag had improved to a mean of seven (range zero to 40) degrees. Using a simple clinical grading system, there were 12 excellent, six good, three fair and two poor results. Three patients had complications; one infection requiring antibiotics, and two who had post-operative extensor lags at the proximal interphalangeal joint which responded to a period of splinting and hand therapy.     

Simulation of Slip-Oxidation Process by Mesh Adaptivity in a Cohesive Zone Framework

Adaptive oxide thickness was developed in a cohesive element based multi-physics model including a slip-oxidation and diffusion model. The model simulates the intergranular stress corrosion cracking (IGSCC) in boiling water reactors (BWR). The oxide thickness was derived from the slip-oxidation and updated in every structural iteration to fully couple the fracture properties of the cohesive element. The cyclic physics of the slip oxidation model was replicated. In the model, the thickness of the oxide was taken into consideration as the physical length of the cohesive element. The cyclic process was modelled with oxide film growth, oxide rupture, and re-passivation. The model results agreed with experiments in the literature for changes in stress intensity factor, yield stress representing cold work, and environmental factors such as conductivity and corrosion potential.     

Subclinical bilateral involvement of the hip in patients with slipped capital femoral epiphysis—a multicentre study

Purpose

This study was conducted to assess the posterior inclination of the contralateral femoral epiphysis in patients with unilateral slipped capital femoral epiphysis (SCFE).

Methods

The posterior sloping angle (PSA) was measured using lateral radiographs in 67 patients with a unilateral SCFE and in 41 age-matched normal controls. A symptomatic epiphyseal slip was defined as the development of SCFE.

Results

The contralateral PSA in SCFE patients was more widely distributed and significantly larger compared to controls (15.0° vs. 9.0°, p < 0.0001). Forty-seven hips (70.1 %) had a PSA of greater than 12.8°, which was +2SD of the control hips. Of the 65 hips excluding the two cases with prophylactic pinning, 11 hips (16.9 %) eventually developed a contralateral SCFE during adolescence and their PSA at the initial visit was significantly larger compared to patients without a contralateral SCFE (18.0° vs. 14.3°, p < 0.005) with a cutoff value of 19°.

Conclusions

These findings suggested the possibility of bilateral hip involvement in SCFE patients. Hips with greater degrees of PSA (> 19°) are likely to become symptomatic.