1例192Ir源致外照射轻度骨髓型急性放射病的临床观察与随访

目的 对2005年哈尔滨"7.13"¹⁹²Ir源放射事故受照者1例进行临床观察与12年的医学随访，探讨外照射轻度骨髓型急性放射病的临床治疗及远后效应。方法 详细采集患者病史，收集临床资料，从血液系统改变、心理健康等方面进行总结，评价治疗效果，观察远后效应。结果 早期治疗后，患者造血系统改变、心理创伤、无力综合征、神经衰弱综合征均有所改善，受照后第10年患者开始出现粒系、红系、巨核细胞系同时减少，受照后第13年被诊断患有分离转换障碍，病程中还伴有心力衰竭、肝功异常、免疫力低下、神经衰弱等疾病。治疗后可缓解症状，但易反复。结论 本例轻度骨髓型急性放射病在临床表现与远后效应上有其独特的疾病特点，并发症较多，为今后此类疾病的临床救治提供了参考。     

牙弓形态对牙科全景X射线摄影的影响研究

分析研究牙科全景X射线摄影原理,以及牙弓形态对全景摄影的影响,提出优化设计的主要指导原则,提高其图像质量。分析全球人群的牙弓形态特征参数,对特定的全景摄影运动轨迹进行优化。牙科全景X射线摄影成像效果有诸多影响因素,断层曲线的设计对设备成像会产生决定性影响,尤其是对尖牙部分。优化断层曲线设计可缩小水平垂直放大倍率变化范围,减少几何失真和牙齿重叠。     

Nurses discuss bedside handover and using written handover sheets

Background The analysis of nursing errors in clinical management highlighted that clinical handover plays a pivotal role in patient safety. Changes to handover including conducting handover at the bedside and the use of written handover summary sheets were subsequently implemented. Aim The aim of the study was to explore nurses’ perspectives on the introduction of bedside handover and the use of written handover sheets. Method Using a qualitative approach, data were obtained from six focus groups containing 30 registered and enrolled (licensed practical) nurses. Thematic analysis revealed several major themes. Findings Themes identified included: bedside handover and the strengths and weaknesses; patient involvement in handover, and good communication is about good communicators. Finally, three sources of patient information and other issues were also identified as key aspects. Conclusions How bedside handover is delivered should be considered in relation to specific patient caseloads (patients with cognitive impairments), the shift (day, evening or night shift) and the model of service delivery (team versus patient allocation). Implications for nursing management Flexible handover methods are implicit within clinical setting issues especially in consideration to nursing teamwork. Good communication processes continue to be fundamental for successful handover processes.     

Beta-catenin is temporally regulated during normal liver development

BACKGROUND & AIMS: beta-Catenin, a key component of the Wnt pathway, plays an important role in unregulated liver growth in liver tumors, in regulated growth during liver regeneration, and in ex vivo embryonic liver cultures. METHODS: We used developing livers from several stages of gestational development to examine beta-catenin expression, protein-protein interactions, localization, and regulation in prenatal and postnatal livers. RESULTS: Microarray, Northern, and protein analyses showed peak expression of beta-catenin during early liver development at Embryonic day 10 (E10)-E12, followed by a decrease and a complete loss of normal beta-catenin (97-kilodalton species) after E16 through the remaining prenatal period. At the early stages, beta-catenin localized to the cytoplasm and nuclei of resident cells in addition to its normal membranous localization, which was seen at all later stages and in adult liver. Decreases in beta-catenin levels at E14 onward coincided with its decreased gene expression and increased degradation, as seen by an increase in serine 45/threonine 41-phosphorylated beta-catenin and its other negative regulators, such as axin, adenomatous polyposis coli gene product (APC), and glycogen synthase kinase-3 beta. Finally, we showed an intact association of E-cadherin and beta-catenin despite the loss of beta-catenin at E16-E18, owing to the presence of membrane-associated smaller-molecular-weight beta-catenin species. CONCLUSIONS: We also identified a stage-specific expression and regulation of beta-catenin during liver development that might be crucial for physiological liver development. Nuclear and cytoplasmic beta-catenin corresponded to cell proliferation in liver development. Finally, a smaller-molecular-weight species of beta-catenin might be maintaining normal interactions at the membrane.     

A test of the chromosomal theory of ecotypic speciation in Anopheles gambiae

The role of chromosomal inversions in speciation has long been of interest to evolutionists. Recent quantitative modeling has stimulated reconsideration of previous conceptual models for chromosomal speciation. Anopheles gambiae, the most important vector of human malaria, carries abundant chromosomal inversion polymorphism nonrandomly associated with ecotypes that mate assortatively. Here, we consider the potential role of paracentric inversions in promoting speciation in A. gambiae via "ecotypification," a term that refers to differentiation arising from local adaptation. In particular, we focus on the Bamako form, an ecotype characterized by low inversion polymorphism and fixation of an inversion, 2Rj, that is very rare or absent in all other forms of A. gambiae. The Bamako form has a restricted distribution by the upper Niger River and its tributaries that is associated with a distinctive type of larval habitat, laterite rock pools, hypothesized to be its optimal breeding site. We first present computer simulations to investigate whether the population dynamics of A. gambiae are consistent with chromosomal speciation by ecotypification. The models are parameterized using field observations on the various forms of A. gambiae that exist in Mali, West Africa. We then report on the distribution of larvae of this species collected from rock pools and more characteristic breeding sites nearby. Both the simulations and field observations support the thesis that speciation by ecotypification is occurring, or has occurred, prompting consideration of Bamako as an independent species.     

NF2蛋白518位丝氨酸磷酸化状态对其分子内相互作用机制的结构生物学及生物化学研究

 目的  揭示NF2 (neurofibromatosis type 2)蛋白518位丝氨酸的磷酸化如何对其结构与功能进行调节。  方法  解析野生型NF2^WT(无模拟磷酸化突变)和突变型NF2^S518D(模拟518位丝氨酸被磷酸化的突变体)蛋白的晶体结构,进一步利用体外Pull-down实验及荧光共振能量转移(fluorescence resonance energy transfer,FRET)实验检测了NF2的分子内相互作用。  结果  由于NF2的C-端在结晶过程中降解,未能观察到NF2^WT和NF2^S518D两种蛋白质构象的差异,结构分析发现NF2的N-端FERM(Four-point one,Ezrin,Radixin,Moesin)结构域与已有结构报道的FERM结构域具有相似的空间构象。体外Pull-down实验证明生化实验结果提示,相对NF2^WTC-端蛋白质而言,NF2^S518D的C-端蛋白质与NF2的N-端蛋白质结合更强。FRET实验在波长525 nm处,检测到全长NF2^S518D比全长NF2^WT产生更强的FRET信号。  结论  野生型NF2^WT处于“开放”状态而模拟磷酸化的突变型NF2^S518D处于“闭合”状态。     

盐酸普拉克索B晶型的制备和表征

目的 制备盐酸普拉克索的B晶型并优化制备工艺,同时进行结构表征和稳定性研究。方法 制备盐酸普拉克索的B晶型,采用热重法(TGA)、差示扫描量热法(DSC)、X射线粉末衍射(PXRD)、X射线单晶衍射(SXRD)等分析手段,对盐酸普拉克索B晶型进行表征研究。结果 制备得到了盐酸普拉克索B晶型,其晶型属正交晶系,空间群P2₁2₁2₁,结构中不含溶剂(包括水)。盐酸普拉克索B晶型热处理后晶型不发生转变。结论 盐酸普拉克索B晶型为无水晶型,热稳定性优于一水合物晶型,具有高温稳定性。     

Likelihood‐based dynamic factor analysis for measurement and forecasting

We present new results for the likelihood‐based analysis of the dynamic factor model. The latent factors are modelled by linear dynamic stochastic processes. The idiosyncratic disturbance series are specified as autoregressive processes with mutually correlated innovations. The new results lead to computationally efficient procedures for the estimation of the factors and for the parameter estimation by maximum likelihood methods. We also present the implications of our results for models with regression effects, for Bayesian analysis, for signal extraction, and for forecasting. An empirical illustration is provided for the analysis of a large panel of macroeconomic time series.     

Effect of intermittent versus continuous energy restriction on weight loss,maintenance and cardiometabolic risk: A randomized 1-year trial

Background & aims

Long-term adherence to conventional weight-loss diets is limited while intermittent fasting has risen in popularity. We compared the effects of intermittent versus continuous energy restriction on weight loss, maintenance and cardiometabolic risk factors in adults with abdominal obesity and ≥1 additional component of metabolic syndrome.

复方半枝莲防治二乙基亚硝胺诱发大鼠肝癌的研究

目的 :研究复方半枝莲 (SBC)对二乙基亚硝胺 (DEN)诱发大鼠肝癌的防治作用。方法 :利用免疫组化、流式细胞仪、血清和组织生化等检测方法 ,分别在第 14周和第 2 4周观察 SBC对 DEN诱发的肝癌形成过程的影响。结果 :中药组 14周时大鼠肝脏异型性增生灶明显较模型组少 ,2 4周时形成的肝癌结节小而少 ,模型组、中药组肝癌发生率分别为 75 .0 %、5 0 .0 % ;免疫组化显示中药组大鼠肝组织谷胱甘肽 - S-转移酶胎盘型阳性灶面积明显低于模型组 ;肝组织匀浆上清液谷胱甘肽 - S-转移酶含量以及血清 λ-谷氨酰转移酶、碱性磷酸酶、谷丙转氨酶含量也明显低于模型组 ;流式细胞仪检测结果显示 ,中药组大鼠肝细胞 G0 - G1 期比例下降 ,G2 - M期比例升高。结论 :SBC能抑制癌前病变 ,延缓肝癌的形成 ,降低肝癌发病率 ,其作用机制之一可能为阻滞 G2 - M期细胞进展 ,从而抑制DEN引起的肝细胞的去分化和恶性增殖