水热沉积电压对C-AlPO_4涂层显微结构的影响

以方石英型磷酸铝(C-A1PO4)粉体为原料,异丙醇为溶剂,碘为荷电介质,采用水热电泳沉积方法在涂有SiC涂层的碳纤维增强碳(C/C-SiC复合材料表面制备了C-A1PO4外涂层.借助X射线衍射和扫描电镜表征了涂层的晶相组成和显微结构.研究了沉积电压对C-A1PO4涂层显微结构的影响,并测试了涂层的抗氧化性能.结果表明:在180～220V范围内,水热沉积电压对涂层的显微结构有较大的影响,220V时制备的涂层致密均匀.涂层的沉积量以及涂层与基体的结合强度随着沉积电压的升高而增加;单位面积沉积量与时间的二次方根之间符合线性关系.与包埋法制备的SiC涂层相比,水热电泳沉积法制备的C-A1PO4涂层具有更好的抗氧化性能,涂层样品在1500℃的空气中氧化37h后质量损失仅为0.53%.     

稀土配合物杂化材料的制备与性能研究

综述了近年来稀土配合物杂化材料的制备和性能．按基质的不同，稀土配合物杂化材料可分为稀土配合物，无机杂化材料，稀土配合物，有机杂化材料以及稀土配合物，混合基质杂化材料。本文对以上3种杂化材料的优缺点进行了较为详细的分析，并提出一步法制备稀土配合物杂化材料，以简化合戍步骤，提高稀土配合物在基质分布的均匀性，因而该方法有望戍为制备稀土配合物杂化材料的一个重要发展方向。     

微乳液组分对体系增溶水量的影响及纳米羟基磷灰石的制备

应用电导率法研究了TritonX-100/正戊醇／环己烷体系中各组分及条件对微乳液最大增溶水量的影响。结果表明：当表面活性剂TritonX-100用量为3ml，助表面活性剂选正戊醇用量为1ml，环己烷为油相，温度为48℃，Ca（NO3）2溶液与（NH4）2HPO4溶液分别为0．24和0．14mol／L时，体系增溶水量最大，可得到较高产率的纳米羟基磷灰石。并且用XRD和TEM手段对产物进行了表征。     

Management of sternal and abdominal wounds in a pediatric heart transplant patient

A 14-year-old girl with congenital heart disease underwent ventricular assist device placement before cardiac transplantation. The inability to close her abdominal fascia necessitated the placement of Prolene mesh, which subsequently became exposed and contaminated when her incision dehisced. Stable closure was obtained with Vicryl mesh and a rectus abdominis turnover flap. Her posttransplant course was notable for compression of the donor heart, necessitating prolonged open sternotomy. She failed an attempt at delayed sternal closure due to compression of the right ventricle by the sternum. In addition to standard pectoralis advancement flaps, a pedicled osseous sternal flap based on her left internal mammary artery was developed to avoid ventricular compression yet still provide some protection to the mediastinum. Alternative uses of this vascularized bone flap to assist with chest wall reconstruction are discussed.     

Narratives of breast symptom discovery and cancer diagnosis: psychologic risk for advanced cancer at diagnosis

In spite of cancer screening programs, women continue to present with advanced breast cancer. How do women decide whether and when to seek an evaluation for self-discovered symptoms? This study examined 104 narratives told by 80 Anglo-, Latina-, and African-American women who participated in 1 of 16 community-based focus groups. The women's narratives contained powerful thematic messages about breast cancer and their expected behavior in the event of a self-discovered breast symptom. Narrative explanations that predicted an increased likelihood of advanced disease at diagnosis included these factors: incorrect symptom attributions and risk estimations; reluctance to consider the threat posed by the symptom; failure to tell another person about the symptom; and expectations of abandonment by male partners, deportation, prejudice, and refusal of treatment due to poverty. Stories of advanced breast cancer also told of reliance on alternative healing, concerns about overwhelming family resources, and extreme modesty that inhibited obtaining a physical examination. Interventions aimed at earlier detection of breast cancer must connect with the beliefs and assumptions embedded in these narratives, provide pragmatic solutions for perceived constraints on seeking evaluations of self-discovered symptoms, and explore the use of community narratives to confirm the value of early detection of breast cancer.     

Outbreak of Salmonella serotype Hartford infections associated with unpasteurized orange juice

CONTEXT: Acidic foods such as orange juice have been thought to be unlikely vehicles of foodborne illness. OBJECTIVE: To investigate an outbreak of Salmonella enterica serotype Hartford (Salmonella Hartford) infections among persons visiting a theme park in Orlando, Fla, in 1995. DESIGN: Review of surveillance data, matched case-control study, laboratory investigation, and environmental studies. SETTING: General community. PARTICIPANTS: The surveillance case definition was Salmonella Hartford or Salmonella serogroup C1 infection in a resident of or a visitor to Orlando in May or June 1995. In the case-control study, case patients were limited to theme park hotel visitors and controls were matched to case patients by age group and hotel check-in date. MAIN OUTCOME MEASURES: Risk factors for infection and source of implicated food. RESULTS: Sixty-two case patients from 21 states were identified. Both Salmonella Hartford and Salmonella enterica serotype Gaminara (Salmonella Gaminara) were isolated from stool samples of 1 ill person. Thirty-two case patients and 83 controls were enrolled in the case-control study. Ninety-seven percent of case patients had drunk orange juice in the theme park vs 54% of controls (matched odds ratio, undefined; 95% confidence interval, 5.2 to undefined). The orange juice was unpasteurized and locally produced. Salmonella Gaminara was isolated from 10 of 12 containers of orange juice produced during May and July, indicating ongoing contamination of juice probably because of inadequately sanitized processing equipment. CONCLUSIONS: Unpasteurized orange juice caused an outbreak of salmonellosis in a large Florida theme park. All orange juice was recalled and the processing plant closed. Pasteurization or other equally effective risk-management strategies should be used in the production of all juices.     

Multiple channels mediate calcium leakage in the A7r5 smooth muscle-derived cell line

Ca2+ entry under resting conditions may be important for contraction of vascular smooth muscle, but little is known about the mechanisms involved. Ca2+ leakage was studied in the A7r5 smooth muscle-derived cell line by patch-clamp techniques. Two channels that could mediate calcium influx at resting membrane potentials were characterized. In 110 mM Ba2+, one channel had a slope conductance of 6.0 +/- 0.6 pS and an extrapolated reversal potential of +41 +/- 13 mV (mean +/- SD, n = 8). The current rectified strongly, with no detectable outward current, even at +90 mV. Channel gating was voltage independent. A second type of channel had a linear current-voltage relationship, a slope conductance of 17.0 +/- 3.2 pS, and a reversal potential of +7 +/- 4 mV (n = 9). The open probability increased e-fold per 44 +/- 10 mV depolarization (n = 5). Both channels were also observed in 110 mM Ca2+. Noise analysis of whole-cell currents indicates that approximately 100 6-pS channels and 30 17-pS channels are open per cell. These 6-pS and 17-pS channels may contribute to resting calcium entry in vascular smooth muscle cells.