Liver Segmentation Based on 3D Statistical Shape Model

基于三维统计模型的肝脏分割是医学图像处理领域最近几年兴起的一种分割方法,其以分割效果好和错误率低得到研究者关注.但该分割算法对模型的初始定位敏感,人工定位容易引入误差,这限制了三维统计模型算法的进一步应用.描述了肝脏平均模型的构造和应用,改进了平均模型的加权形式,提出了基于统计直方图的全自动定位方法,简化了模型的定位.Liver segmentation based on three-dimensional statistical shape model is a novel method in the medical image processing field recently.The advantage of good segmentation performance and low error rate has aroused the focus of researcher.In addition,the location of model in volume data effect the segmentation.Artificial location may introduces extra error,which limits its further application in the segmentation of the liver in practice.In this article,we discribe the constrution of statistical shape model.We propose the form of the weighted average model in this paper.Automatic location method based on statistical histogram is proposed to point the positioning of the model.国家自然科学基金项目(61102137;61271336

柔细束丝藻土臭素合成酶基因的克隆及表达分析

土臭素(Geosmin)是一种具有土霉异味的次级代谢产物,对水体具有严重的影响.为探讨柔细束丝藻(Aphanizomenon gracile)土臭素的合成机制以及环境因子对其土臭素产量的影响,利用高效热不对称交错PCR(High-efficiency thermal asymmetric interlaced PCR,hi TAIL-PCR)技术对柔细束丝藻藻株WH-1的土臭素合成酶基因进行克隆,并对该基因在不同温度和光强下的表达情况进行实时荧光定量PCR(RT-PCR)分析.结果显示本研究成功克隆柔细束丝藻藻株WH-1的土臭素合成酶基因(geo),geo全长2 262 bp,编码753个氨基酸.低温(15℃)、强光(35μmol m~(-2) s~(-1))以及不间断光照处理均有利于geo的表达.这表明hi TAIL-PCR技术作为一种高效、低廉的染色体步移技术具有较好的应用价值,同时为异味物质的监测及防治提供部分理论基础

柔细束丝藻土臭素合成酶基因的克隆及表达分析

土臭素(Geosmin)是一种具有土霉异味的次级代谢产物,对水体具有严重的影响.为探讨柔细束丝藻(Aphanizomenon gracile)土臭素的合成机制以及环境因子对其土臭素产量的影响,利用高效热不对称交错PCR(High-efficiency thermal asymmetric interlaced PCR,hi TAIL-PCR)技术对柔细束丝藻藻株WH-1的土臭素合成酶基因进行克隆,并对该基因在不同温度和光强下的表达情况进行实时荧光定量PCR(RT-PCR)分析.结果显示本研究成功克隆柔细束丝藻藻株WH-1的土臭素合成酶基因(geo),geo全长2 262 bp,编码753个氨基酸.低温(15℃)、强光(35μmol m~(-2) s~(-1))以及不间断光照处理均有利于geo的表达.这表明hi TAIL-PCR技术作为一种高效、低廉的染色体步移技术具有较好的应用价值,同时为异味物质的监测及防治提供部分理论基础

柔细束丝藻土臭素合成酶基因的克隆及表达分析

土臭素(Geosmin)是一种具有土霉异味的次级代谢产物,对水体具有严重的影响.为探讨柔细束丝藻(Aphanizomenon gracile)土臭素的合成机制以及环境因子对其土臭素产量的影响,利用高效热不对称交错PCR(High-efficiency thermal asymmetric interlaced PCR,hi TAIL-PCR)技术对柔细束丝藻藻株WH-1的土臭素合成酶基因进行克隆,并对该基因在不同温度和光强下的表达情况进行实时荧光定量PCR(RT-PCR)分析.结果显示本研究成功克隆柔细束丝藻藻株WH-1的土臭素合成酶基因(geo),geo全长2 262 bp,编码753个氨基酸.低温(15℃)、强光(35&mu;mol m~(-2) s~(-1))以及不间断光照处理均有利于geo的表达.这表明hi TAIL-PCR技术作为一种高效、低廉的染色体步移技术具有较好的应用价值,同时为异味物质的监测及防治提供部分理论基础.</p

Progesterone generates cancer stem cells through membrane progesterone receptor-triggered signaling in basal-like human mammary cells

Among the four main subtypes of breast cancer, basal-like breast cancer (the predominant subtype of triple-negative breast cancer) is of particular concern, due to its high frequency, relative lack of effective therapies and poor prognosis. Ionizing radiation (for example as treatment for other cancers) and cumulative exposure to steroid hormones (as seen in postmenopausal women under hormone replacement therapy) are known risk factors for breast cancer. Because of their tumor-initiating properties, cancer stem cells (CSCs) were proposed to be responsible for relapse and metastasis. In MCF10A non-cancerous basal-like PR-negative cells, progesterone treatment and 1 Gy X-rays generated ALDH+ and CD44+/CD24- CSCs. Here, we report that progesterone activated the Pi3k/Akt pathway via membrane progesterone receptor (mPR). Inhibition of the Pi3k/Akt pathway counteracted the generation of CSCs by progesterone and irradiation. The stimulation of Pi3K/Akt by progesterone resulted in the inactivation of FOXO3 and a downregulation of miR-29 expression. Stabilization of miR-29 expression impeded the generation of CSCs, while its inhibition alone was sufficient to generate CSCs. This study provides a new mechanistic basis for progesterone and radiation-induced breast cancer risk. In addition, the elucidation of new pathways and miRNA regulations involved in CSC generation and maintenance may open the door to potential new strategies for basal cancer primary or adjuvant therapy, by blocking non-CSCs from replenishing the pool of CSCs and by targeting mechanisms responsible for CSC maintenance. Such CSC-focused therapies may be effective at preventing metastasis and relapse.AACR(American Association for Cancer Research) Annual Meeting 201

Progesterone generates basal-like cancer stem cells via membrane progesterone receptor-triggered signaling

Basal-like breast cancer is of particular concern, due to its high frequency, lack of effective therapies and poor prognosis. Ionizing radiation and cumulative exposure to steroid hormones are known risk factors for breast cancer. Because of their tumor-initiating properties, cancer stem cells (CSCs) were proposed to be responsible for relapse and metastasis. In MCF10A non-cancerous basal-like PR-negative cells, progesterone (P4) treatment and 1 Gy X-rays generated ALDH+ and CD44+/CD24- CSCs. Here, we report that P4 activated the Pi3k/Akt pathway via membrane progesterone receptor (mPR), resulting in the inactivation of FOXO transcriptional activity, the upregulation of snail and slug expression and a downregulation of miR-29 expression, which led to increased levels of KLF4, a transcription factor required for breast CSC maintenance. Stabilization of miR-29 expression impeded the generation of CSCs, while its inhibition alone was sufficient to generate CSCs. The elucidation of new pathways and miRNA regulations involved in basal-like CSC maintenance may open the door to new strategies for BBC primary or adjuvant therapy, which may be effective at preventing metastasis and relapse.第７４回日本癌学会学術総

Vertical distribution of zooplankton in the continental slope southwest of Nansha Islands,South China Sea

浮游动物是海洋生态系统物质和能量转移的关键环节,也是渔业资源的重要饵料,其种类组成和数量分布均有明显的垂直分层现象。利用2011年4月在南沙群岛西南大陆斜坡海域开展的18个站点90份样品的调查数据,对该海域浮游动物的垂直分布进行了研究,表明:(1)该海域浮游动物种类组成丰富,共出现18个类群580种(类);(2)浮游动物种类组成垂直变化明显,特定水层出现的种类数占总种数的43.6%,各水层均出现的种类仅占总种数的15.8%;(3)优势种组成复杂,垂直变化明显,单一种类的优势度不高;(4)浮游动物平均密度和湿重生物量分别为206.27Ind/M3、94.03Mg/M3,密度和生物量均以0~2M层和30~75M层较高,沿水深梯度的变化呈明显的双峰型;(5)浮游动物数量的垂直变化主要受温跃层影响,温跃层内浮游动物数量最高,温跃层上方和下方的水层内数量较低;(6)南沙西南大陆斜坡区浮游动物生产力水平较高,表明该海域渔业资源有一定的开发潜力。As dietary organisms of fish stocks,zooplankton is a key link of mass and energy transformation in the marine ecosystem.There are vertical changes in the species compositions and abundances of zooplankton in the water column.Based on 90samples from 18stations collected in April 2011,the vertical distribution of zooplankton in the continental slope to the southwest of Nansha Islands,South China Sea was studied.It was found that the continental slope waters are rich in zooplankton species,with a total number of 580species belonging to 18taxa being recorded.There are obvious vertical variations in the zooplankton species compositions.The numbers of zooplankton species occurring in a specific deep group could take up 43.6%of the total number of species,while the number of species occurring in all deep groups made up only 15.8%of the total number of species.There was no obvious dominant species and the dominancy of any single species was low.The overall mean density and wet biomass of zooplankton were 206.27ind/m3 and 94.03mg/m3 respectively.The higher density and biomass were found in the deep groups of 0—2mand 30—75mand the vertical distribution showed a pattern of double-humped curve.Thermocline was an important factor in the vertical distribution of zooplankton.The abundances of zooplankton in the thermocline layer were higher than those in the upper mixed layer and the water layers bellow the thermocline.Compared to the other regions in the South China Sea,zooplankton abundances were the highest in the continental slope southwest off Nansha Islands,suggesting potentials for fishery development in the region.中央级科研院所基本科研业务费专项资金(中国水产科学研究院南海水产研究所)资助项目(2012TS02); 农业部财政重大专项(NFZX2013); 国家科技支撑计划课题(2013BAD13B06