Multi-Task Linear Programming Discriminant Analysis for the Identification of Progressive MCI Individuals

Accurately identifying mild cognitive impairment (MCI) individuals who will progress to Alzheimer''s disease (AD) is very important for making early interventions. Many classification methods focus on integrating multiple imaging modalities such as magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (FDG-PET). However, the main challenge for MCI classification using multiple imaging modalities is the existence of a lot of missing data in many subjects. For example, in the Alzheimer''s Disease Neuroimaging Initiative (ADNI) study, almost half of the subjects do not have PET images. In this paper, we propose a new and flexible binary classification method, namely Multi-task Linear Programming Discriminant (MLPD) analysis, for the incomplete multi-source feature learning. Specifically, we decompose the classification problem into different classification tasks, i.e., one for each combination of available data sources. To solve all different classification tasks jointly, our proposed MLPD method links them together by constraining them to achieve the similar estimated mean difference between the two classes (under classification) for those shared features. Compared with the state-of-the-art incomplete Multi-Source Feature (iMSF) learning method, instead of constraining different classification tasks to choose a common feature subset for those shared features, MLPD can flexibly and adaptively choose different feature subsets for different classification tasks. Furthermore, our proposed MLPD method can be efficiently implemented by linear programming. To validate our MLPD method, we perform experiments on the ADNI baseline dataset with the incomplete MRI and PET images from 167 progressive MCI (pMCI) subjects and 226 stable MCI (sMCI) subjects. We further compared our method with the iMSF method (using incomplete MRI and PET images) and also the single-task classification method (using only MRI or only subjects with both MRI and PET images). Experimental results show very promising performance of our proposed MLPD method.     

乙型脑炎病毒DNA初免-蛋白加强策略在小鼠模型上的免疫效应评价

为了评价基因Ⅰ型乙型脑炎病毒prM-E DNA疫苗与prM和EⅢ融合抗原亚单位疫苗采用DNA初免-蛋白加强免疫策略对小鼠的免疫效果,本研究将prM-E融合基因插入到pVAX1真核表达载体中,构建重组表达载体prM-E-pVAX1作为DNA疫苗进行初免,利用原核表达系统获得的prM和EⅢ融合抗原作为亚单位疫苗进行加强免疫。将32只4−6周龄雌性BALB/c小鼠随机分成4组,设置prM-E-pVAX1 DNA疫苗组、DNA初免-蛋白加强免疫组、prM和EⅢ融合抗原亚单位疫苗组及pVAX1载体对照组,通过ELISA检测血清中特异性抗体水平;通过噬斑减少中和试验滴定中和抗体滴度;通过细胞因子表达丰度和淋巴细胞增殖试验分析不同疫苗免疫组诱导产生的细胞免疫反应。结果表明,用DNA初免-蛋白加强策略免疫的小鼠诱导产生的中和抗体滴度略高于prM和EⅢ融合抗原亚单位疫苗免疫组,显著高于prM-E-pVAX1 DNA疫苗免疫组。DNA初免-蛋白加强策略在小鼠模型中诱导产生了有效的Th1/Th2型免疫反应,特别是显著诱导了Th1型细胞免疫反应。本研究为预防流行性乙型脑炎提供了新的免疫策略和理论参考依据。     

Cloning and Drought Resistance Analysis of Soybean <i>GmHsps_p23-like</i> Gene

Soybean (Glycine max (L.) Merr.) is an important cultivated crop, which requires much water during its growth, and drought seriously affects soybean yields. Studies have shown that the expression of small heat shock proteins can enhance drought resistance, cold resistance and salt resistance of plants. In this experiment, soybean GmHsps_p23-like gene was successfully cloned by RT-PCR, the protein encoded by the GmHsps_p23-like gene was subjected to bioinformatics analysis, and the pCAMBIA3301-GmHsps_p23-like overexpression vector and pCBSG015-GmHsps_p23-like gene editing vector were constructed. Agrobacterium-mediated method was used to transform soybeans to obtain positive plants. RT-PCR detection, rehydration experiment and drought resistance physiological and biochemical index detection were performed on the T₂ generation positive transgenic soybean plants identified by PCR and Southern hybridization. The results showed that the overexpression vector plant GmHsps_p23-like gene expression increased. After rehydration, the transgenic overexpression plants returned to normal growth, and the damage to the plants was low. After drought stress, the SOD and POD activities and the PRO content of the transgenic overexpression plants increased, while the MDA content decreased. The reverse was true for soybean plants with genetically modified editing vectors. The drought resistance of the overexpressed soybeans under drought stress was higher than that of the control group, and had a stronger drought resistance. It showed that the expression of soybean GmHsps_p23-like gene can improve the drought resistance of soybean. The cloning and functional verification of soybean GmHsps_p23-like gene had not been reported yet. This is the first time that PCR technology has been used to amplify the soybean GmHsps_p23-like gene and construct an expression vector for this gene. This research has laid the foundation for transgenic technology to improve plant drought resistance and cultivate new drought-resistant transgenic soybean varieties.     

铁皮石斛微卫星SSR设计与应用

通过Websat对来源于NCBI公共数据库的2 447条石斛属(Dendrobium)核苷酸序列进行简单重复序列SSR的搜索,剔除冗余序列后,找到124个SSR位点。利用primer3.0软件设计引物75对,并通过改良的方法提取铁皮石斛DNA作为模板,对铁皮石斛(Dendrobium officinaleKimuraetMigo)的SSR引物进行筛选,选出21对有较清晰且稳定的目标扩增产物的引物,对8个种源的铁皮石斛进行多态性分析和聚类分析,得到8个种源的铁皮石斛进行遗传多样性和亲缘关系。     

Effect of autophagy on ferroptosis in foam cells via Nrf2

Molecular and Cellular Biochemistry - The progression of atherosclerotic plaque is accelerated by death of foam cells during the development of the plaque. There are several forms of foam cell...     

红花花青素合成酶基因的克隆及表达分析

根据红花转录物测序结果中得到的中间序列,采用R11-PCR和RACE方法从红花花瓣中克隆到1个4嬲基因的全长cDNA,该基因全长序列1226bp,具有完整的开放阅读框（ORF）,共1050bp,编码349个氨基酸。生物信息学软件分析显示,该基因编码的蛋白理论分子量约为82．27kDa,等电点为5．09,序列里含有典型的加尾信号序列AATAA和Poly（A）。保守结构域预测表明,该基因编码的蛋白具有典型的ANS蛋白功能结构域,其保守结构域中含有铁离子及2．0-酮戊二酸结合位点。结合其他物种的臌因构建系统树表日月,红花ANS蛋基因与其他物种氨基酸具有一定的同源性,其中与芍药的亲缘关系最近。应用实时荧光定量PCR分析表明,ANS基因在红花的初花期和盛花期的表达量最高。     

Radiation pressure on a biconcave human Red Blood Cell and the resulting deformation in a pair of parallel optical traps

We calculated the three‐dimensional optical stress distribution and the resulting deformation on a biconcave human red blood cell (RBC) in a pair of parallel optical trap. We assumed a Gaussian intensity distribution with a spherical wavefront for each trapping beam and calculated the optical stress from the momentum transfer associated with the reflection and refraction of the incident photons at each interface. The RBC was modelled as a biconcave thin elastic membrane with uniform elasticity and a uniform thickness of 0.25 μm. The resulting cell deformation was determined from the optical stress distribution by finite element software, Comsol Structure Mechanics Module, with Young's modulus (E) as a fitting parameter in order to fit the theoretical results for cell elongation to our experimental data. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Rhodococcus kronopolitis sp. nov., a novel actinobacterium isolated from a millipede (Kronopolites svenhedind Verhoeff)

A novel actinobacterium, designated strain NEAU-ML12^T, was isolated from a millipede (Kronopolites svenhedind Verhoeff), which was collected from Fenghuang Mountain in Wuchang, Heilongjiang Province, north China. The strain was characterized using a polyphasic approach. Strain NEAU-ML12^T was found to have morphological and chemotaxonomic characteristics typical of the members of the genus Rhodococcus. 16S rRNA gene sequence similarity analysis showed that the strain NEAU-ML12^T belongs to the genus Rhodococcus, and was most closely related to Rhodococcus tukisamuensis Mb8^T (98.9 %) and Rhodococcus koreensis DNP505^T (97.7 %). Phylogenetic analysis based on 16S rRNA gene sequences also demonstrated that strain NEAU-ML12^T should be classified in the genus Rhodococcus, forming a distinct clade with R. tukisamuensis Mb8^T supported by a 99 % bootstrap value. However, the DNA–DNA relatedness between strain NEAU-ML12^T and R. tukisamuensis Mb8^T was found to be 41.9 ± 0.7 %. Furthermore, strain NEAU-ML12^T could also be differentiated from R. tukisamuensis Mb8^T and other closely related strains (R. koreensis DNP505^T and Rhodococcus maanshanensis M712^T) by morphological and physiological characteristics. Therefore, it is proposed that strain NEAU-ML12^T represents a novel species of the genus Rhodococcus, for which the name Rhodococcus kronopolitis sp. nov. is proposed. The type strain is NEAU-ML12^T (=CGMCC 4.7145^T = DSM 46702^T).     

Microbial Ecology and Association of Bacillus thuringiensis in Chicken Feces Originating from Feed

To explain the association of Bacillus thuringiensis (Bt) with animal feces, an ecological analysis in chickens was conducted by introducing a cry ^? strain marked by production of green fluorescent protein (GFP). After feeding with the tagged Bt strains, the feces of the tested chickens were collected at different times, isolated, and the morphology of Bt was observed. It was shown that Bt strain HD-73GFP in spore form could be isolated from feces of chickens for a period of 13 d, and then it disappeared thereafter. Bt could be detected only up to day 4 (but not thereafter), when chickens were fed with vegetative cells of HD-73GFP. To confirm the source of newly isolated strains, the gfp gene was examined by polymerase chain reaction (PCR), which showed that all the isolated strains harbored the marker gene. Recent data from isolation and PCR had suggested that fecal Bt strains had originated from food. Chicken tissues were thus dissected to isolate Bt strains and to investigate whether Bt could be located in vivo. Bt was located within the duodenum in spore form. Compared to the morphology of the isolated strains at different growth times, the growth rates of all the tested Bt had little changes when passing through the digestive system to the feces. Dissection of the chickens confirmed that Bt was safe for the tested animal.