3T高清RS-EPI DWI与SS-EPI DWI序列诊断中耳胆脂瘤的效果比较

目的比较用高清读出分段平面回波-弥散加权成像(readout-segmented-echo-planar imaging-diffusion-weighted imaging, RS-EPI DWI)与单激发回波平面-弥散加权成像(single-shot echo-planar imaging-diffusion-weighted imaging, SS-EPI DWI)技术检测中耳胆脂瘤中的效果。方法 21例临床诊断中耳胆脂瘤和7例慢性化脓性中耳炎阴性对照用于检验RS-EPI DWI序列MRI检测胆脂瘤的能力。术中根据经验判断是否有胆脂瘤,并送病理检测。每位患者分别采用T2加权快速自旋回波(T2-weighted turbo spin echo, T2W-TSE)、RS-EPI DWI和单激发回波平面-弥散加权成像(single-shot echo-planar imaging-diffusion-weighted imaging, SS-EPI DWI)序列行MRI检查。采用ImageJ软件的图像计算功能将同一层面的RS-EPI DWI的B值1000影像分别与T2W-TSE MRI和CT影像进行融合定位。测量胆脂瘤阳性信号的最小直径,将RS-EPI DWI序列与SS-EPI DWI序列获取的影像进行比较。结果胆脂瘤在RS-EPI DWI序列b值为0的影像学特征表现与T2W-TSE MRI相似,然而在RS-EPI DWI序列b值为1000的图像中,胆脂瘤表现为白色高信号,边界清晰,脑脊液等液体为黑色的低信号,脑组织为中等灰白色信号,边缘部位有较强信号,普通炎症病灶表现为黑色低信号。SS-EPI DWI序列b值为0的影像显示脑组织有较大的变形,在SS-EPI DWI序列b值为1000的图像中,胆脂瘤显示为白色高信号,其范围小于RS-EPI DWI序列b值为1000的图像显影。将RS-EPI DWI序列b值为1000的图像与T2W-TSE MRI进行融合精准地验证了前者显示的胆脂瘤的解剖定位,与CT融合显示的解剖定位更加利于识别病灶。RS-EPI DWI检测胆脂瘤的阳性率为100%,无假阴性;SS-EPI DWI检测胆脂瘤的阳性率为81.0%,假阴性率为19.0%,二者相差非常显著(P<0.05, Pearsonχ2检验)。RS-EPI DWI在对照组有1例假阳性,SS-EPI DWI在对照组无假阳性。RS-EPI DWI显示最小尺寸的平均值为1233.3μm,最小值为700μm,SS-EPI DWI显示最小尺寸的平均值为1968.8μm,最小值为1000μm,二者平均值相差非常显著(P<0.01,配对t检验)。RS-EPI DWI显示平均阳性层数为4.2,最多阳性层数为10层,SS-EPI DWI显示平均层数为3.1,最多阳性层数为11层,二者相差非常显著(P<0.01,配对t检验)。结论 RS-EPI DWI较SS-EPI DWI序列检测中耳胆脂瘤的灵敏度更高,形态结构显示更加清晰。     

一种袖带测量过程的物理模型及基于这种模型的新型收缩压测量方法的研究

传统的波动法血压无创测量技术由于利用了统计学原理，因此必然造成测量的个体误差。本文对袖带测量的物理过程进行了研究，在首先发明了袖带波动信号无失真提取技术的基础上，提出了一种袖带测量过程的物理模型，并对这一模型进行了证实。另外，根据这一模型提出了一种人体血压的无创测量方法，该方法不像传统方法那样采用统计学原理［１］，从而避免了所有个体采用统一的血压判据而导致的个体测量误差，实际实验表明，该技术的测量准确性要优于传统的波动法测量技术，这对改善医学临床血压无创自动测量技术的现状是有很大意义的     

Enthalpy Relaxation of Layered Silicate‐Epoxy Nanocomposites

Using standard and temperature‐modulated differential scanning calorimetry, we have studied the segmental relaxation behavior of montmorillonite‐epoxy nanocomposites. The experimental results showed that the incorporation of clay particles caused the epoxy network to exhibit slower relaxation dynamics compared with the neat epoxy resin. Analysis based on the Tool‐Narayanaswamy‐Moynihan (TNM) model indicated that the nanocomposite systems had greater nonlinearity, higher apparent activation energy, and broader relaxation time distribution than the neat epoxy resin. Further analysis based on the Adam‐Gibbs model indicated that the presence of clay nanoparticles decreased the macroscopic configurational entropy of the epoxy network, and increased the size of the cooperative rearrangement region as well as the fundamental energy barrier. The peculiar relaxation behavior observed in the present experiments was attributed to the confinement effect of nanoparticles on molecular entities during the segmental relaxation. This confinement effect led to a stronger temperature dependence of the relaxation behavior near the glass transition temperature, or greater fragility. An inverse correlation between nonexponentiality and fragility was also observed, which is consistent with the results reported in the literature.

The original MDSC curves: complex heat capacity (C_{\rm P}^* ) versus temperature; the inset shows the nonexponentiality parameters (β) for all the samples.     

STAT3和p38在胃癌组织中的表达及意义

目的：检测信号传导及转录活化因子STAT3和p38在胃癌组织中的表达及其与胃癌组织分化程度的相关关系。方法：采用免疫组化二步法检测60例胃癌患者组织标本,其中高-中分化胃癌组30例,低分化胃癌组30例,另设空白对照组30例,分别检测各组STAT3和p38蛋白的表达,分析各组之间表达的差异及其相关性。结果：STAT3、p38阳性信号主要位于胞浆和胞核中,STAT3和p38的表达在胃癌组织明显高于正常胃组织（P〈0.01）,在不同组织分化程度的胃癌组织中有显著差异（P〈0.01）,低分化胃癌组STAT3和p38的表达明显高于高-中分化胃癌组。二者的表达具有相关性。结论：胃癌组织中,STAT3和p38的表达程度明显增高,二者之间存在正相关关系,说明二者可能具有协同和/或交互作用。随着胃癌组织分化程度的降低,二者的表达明显增强。二者的异常激活可能在诱导胃癌的发生、发展和分化中充当重要角色。     

从随机肽库中筛选血管内皮生长因子的抑制剂

目的：从随机噬菌体肽库中筛选血管内皮生长因子（VEGF165）的抑制剂,研究治疗实体瘤生长的小分子药物。方法：以VEGF165分子的受体KDR为靶分子,筛选随机噬菌体环7肽库,通过竞争性洗脱得到能特异结合KDR的阳性噬菌体,以ELISA、细胞免疫组化、细胞ELISA、鸡胚绒毛膜尿囊膜实验和MTT法,鉴定其结合活性和抑制活性。结果：得到5个能特异结合靶分子的阳性噬菌体克隆,它们均可以与表面有KDR表达的细胞结合,其中噬菌体克隆3和13还能抑制VEGF165诱导鸡胚绒毛尿囊膜新生血管形成的活性。但MTT法结果显示,这两种噬菌体小肽对高表达KDR的阳性细胞生长没有明显的抑制活性。结论：从随机噬菌体肽库筛选到了能抑制VEGF165生物活性的克隆,为进一步研究小分子抑瘤药物提供了一定基础。     

Quantitation of four guanine oxidation products from reaction of DNA with varying doses of peroxynitrite

The oxidation products obtained from the reaction of peroxynitrite (ONOO-) with dG include-among others-8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), 2,2-diamino-4[(2-deoxy-beta-d-erythro-pentafuranosyl)amino]-5(2H)-oxazolone (oxazolone), spiroiminodihydantoin, and N1-(beta-d-erythro-pentofuranosyl)-5-guanidinohydantoin (guanidinohydantoin). In the present work, the formation of these products from the treatment of calf thymus DNA with varying amounts of ONOO- was studied quantitatively in vitro. 13C-, 15N-labeled standards were synthesized for the nucleosides of interest, and calf thymus DNA was reacted with ONOO- and digested enzymatically down to the nucleoside level. Specific modifications in the DNA were measured by HPLC separation followed by electrospray ionization tandem mass spectrometric analysis in the selected reaction-monitoring mode. Artifacts of the above four oxidation products, arising from oxidation of dG and/or 8-oxodG during DNA digestion and subsequent workup, were evaluated with 7-15N-dG and/or stable-isotope-labeled 8-oxodG as internal standards. Levels of artifactual 8-oxodG were about 5/10(6) nucleosides. The artifacts of spiroiminodihydantoin and guanidinohydantoin, arising from 8-oxodG, were 3.7% and 0.6% of the measured 8-oxodG values, respectively. No artifacts of oxazolone were detected. 8-OxodG and oxazolone were formed dose-dependently in DNA treated with ONOO-, while the levels of spiroiminodihydantoin and guanidinohydantoin increased significantly at low ONOO- doses, and then dropped off at higher ONOO- doses. The complexity of these dose-response relationships is likely due to the dual role of peroxynitrite as both an oxidant and a nucleophile in competition with water.     

Double-blind, placebo-controlled investigation of amantadine for weight loss in subjects who gained weight with olanzapine

OBJECTIVE: This study sought to determine if amantadine affects weight gain in psychiatric patients taking olanzapine. METHOD: Twenty-one adults who had gained at least 5 lb with olanzapine were randomly assigned to receive amantadine (N=12) or placebo (N=9) in addition to olanzapine. The length of time taking olanzapine ranged from 1 to 44 months. Body mass index, psychiatric status, and fasting blood levels were assessed at baseline and 12 weeks. RESULTS: Significantly fewer subjects taking amantadine gained weight, with a mean change in body mass index of -0.07 kg/m2 for the amantadine group and 1.24 kg/m2 for the placebo group. This effect remained significant when the authors controlled for baseline body mass index and length of olanzapine treatment. No changes in fasting glucose, insulin, leptin, prolactin, and lipid levels were seen. Positive and Negative Syndrome Scale scores remained stable. CONCLUSIONS: Amantadine induced weight stabilization in subjects taking olanzapine and was well tolerated.     

相控型HIFU系统软件的开发与应用

介绍采用计算机图形学和数据库的相关技术,在自主研发的多阵元相控聚焦超声治疗设备上开发了一套可视化HIFU系统软件。经实验验证,该系统软件能够有效制定治疗规划,实施实验治疗方案,促进临床实验研究。     

Exposure to trichloroethylene and its metabolites causes impairment of sperm fertilizing ability in mice.

Trichloroethylene (TCE) is a prevalent occupational and environmental contaminant that has been reported to cause a variety of toxic effects. Here, we have undertaken studies to test the hypothesis that TCE exposure adversely affects sperm function and fertilization. Sperm retrieved from mice exposed to TCE (1000 ppm) by inhalation for 1 to 6 weeks were incubated in vitro with eggs isolated from superovulated female mice. The number of sperm bound per egg was significantly decreased when mice were exposed to TCE for 2 and 6 weeks but not at exposures of 1 and 4 weeks. In vivo fertilization was also determined in superovulated female mice mated with males exposed to TCE for 2 to 6 weeks. The percentages of eggs fertilized, as assessed by the presence of two pronuclei, were significantly decreased after 2 and 6 weeks of TCE exposure. A slight but insignificant decrease was observed after 4 weeks of TCE exposure. The direct effects of TCE and its metabolites, chloral hydrate (CH) and trichloroethanol (TCOH), on in vitro sperm-egg binding were also investigated. Sperm-egg binding was significantly decreased when sperm were pretreated with CH (0.1-10 microg/mL). Significantly lower levels of sperm-egg binding were also detected with TCOH (0.1-10 microg/mL), although the decreases were not as pronounced as those for CH. These results showed that TCE exposure leads to impairment of sperm fertilizing ability, which may be attributed to TCE metabolites, CH, and TCOH.     

烟煤快速加氢热解研究——半焦,挥发分和焦油等生成行为的考察

烟煤快速加氢热解，除获取轻质烃和甲烷等气，液产品外，还得到半焦，焦油和水，半焦中残留挥发分。在氢气氛中快速热解生成半焦中的挥发分低于氮气氛，残留挥发分的多少是衡量快速热解反应程度的标志。加氢热解后生成半焦的堆密度仅为原煤的１／３．５，活性半焦直接加氢反应生成甲烷是引起半焦密度减小的主要原因之一。轻质烃产率与焦油生成量有关，焦油加氢二次反应是轻质烃生成的主要途径。氢气氛中热解生成的水多于氮气氛，气相