基于频谱图像灰度共生矩阵的无损测温方法

本文提出了一种基于哈达玛变换的频谱图像灰度共生矩阵(Hadamard-GLCM)的高强度聚焦超声治疗无损测温方法。利用高强度聚焦超声辐照新鲜离体猪肉组织,获取辐照前后的B超图像的减影图像,采用Hadamard变换对其进行处理,获取频谱图像,将频谱图像的灰度共生矩阵惯性矩作为反应温度变化的信息参数。实验表明:不仅单组数据的Hadamard-GLCM惯性矩(HGMI)和温度能很好的线性拟合,而且多组数据的Hadamard-GLCM惯性矩与温度也成近似的线性关系,而且斜率非常接近,拟合度更接近1,误差小,对温度的分辨能力高,容错能力强,与传统的测温方法相比有着明显的优势,能为HIFU治疗过程中的无损测温提供有效的实时依据。     

云杉矮槲寄生遗传多样性及其群体遗传结构分析

该研究采用CTAB法提取云杉矮槲寄生(Arceuthobium sichuanense)的基因组DNA,利用ITS1片段的序列信息对中国9个不同地理群体的62份云杉矮槲寄生样本的遗传多样性及群体遗传结构进行分析。结果表明:(1)62条ITS1序列共定义16个单倍型(H1~H16),表现出较低的遗传多样性水平(h=0.678 5,π=0.005 9),而群体间的遗传多样性水平则表现出较大差异(h=0~1.000 0,π=0~0.009 4);AMOVA分析显示云杉矮槲寄生群体内的遗传变异占到51.37%,群体间为48.63%。(2)Network单倍型网络分析表明,单倍型H1和H12较为古老,且所有群体对2种单倍型无共享现象;单倍型H1是广布单倍型,存在于青海和甘肃的6个群体中,单倍型H12仅在四川的2个群体中有分布。(3)基于最大似然法(ML)构建的群体聚类和中介邻接法构建的单倍型网络图均显示,四川的3个群体为独立类群,区别于青海、甘肃群体,且甘肃和青海的群体之间没有明显分化。该研究首次报道了云杉矮槲寄生遗传多样性和遗传结构,为进一步研究其进化及后续的病害防控提供了一定的参考。     

Assigning alleles to different loci in amplifications of duplicated loci

Duplicated loci, for example those associated with major histocompatibility complex (MHC) genes, often have similar DNA sequences that can be coamplified with a pair of primers. This results in genotyping difficulties and inaccurate analyses. Here, we present a method to assign alleles to different loci in amplifications of duplicated loci. This method simultaneously considers several factors that may each affect correct allele assignment. These are the sharing of identical alleles among loci, null alleles, copy number variation, negative amplification, heterozygote excess or heterozygote deficiency, and linkage disequilibrium. The possible multilocus genotypes are extracted from the alleles for each individual and weighted to estimate the allele frequencies. The likelihood of an allele configuration is calculated and is optimized with a heuristic algorithm. Monte‐Carlo simulations and three empirical MHC data sets are used as examples to evaluate the efficacy of our method under different conditions. Our new software, mhc‐typer V1.1, is freely available at https://github.com/huangkang1987/mhc-typer .     

Systematics,genetics, and biogeography of intertidal mites (Acari,Oribatida) from the Andaman Sea and Strait of Malacca

This study demonstrates for the first time the presence of marine‐associated mites in the Andaman Sea and Strait of Malacca and reveals a relatively high diversity of these taxa with six species from two different families: Selenoribatidae and Fortuyniidae. Indopacifica, a new genus of Selenoribatidae, is described from Thailand and Malaysia, with two new species, Indopacifica pantai n. sp. and Indopacifica parva n. sp. The genus is characterized by the unique combination of following characters: lacking lamellar ridges, incomplete dorsosejugal suture, fourteen pairs of notogastral setae, and presence of epimeral foveae. A phylogenetic reconstruction based on 18S ribosomal RNA sequences clearly confirms the distinctness of the new genus Indopacifica and places it close to the genus Rhizophobates. The lack of molecular genetic data of possible relatives impedes a clear assessment, and hence, we emphasize the need for further combined approaches using morphological and molecular genetic sequence data. All species show wide distribution areas within this geographic region suggesting that these taxa are good dispersers despite their minute size and wingless body. Molecular genetic data demonstrate recent gene flow between far distant populations of I. pantai n. sp. from the coasts of Thailand and two islands of Malaysia and hence confirm this assumption. The seasonally changing surface currents within this geographic area may favor hydrochorous dispersal and hence genetic exchange. Nevertheless, morphometric data show a slight trend to morphological divergence among the studied populations, whereas this variation is suggested to be a result of genetic drift but also of habitat differences in one population of Alismobates pseudoreticulatus.     

Noncancer risk assessment of arsenic safe and unsafe water uses: Bayesian estimation on cohort study

Cancer and noncancer risk of arsenic exposure depends on arsenic intake through drinking water and diets. The present study evaluated the probability of noncancer effects of arsenic exposure from drinking water and diets in a cohort of 82 participants in arsenic-endemic rural areas, considering arsenic-safe and arsenic-unsafe water uses for three consecutive years. The risk assessment included the collection of last 24 hours' diet replica and urine of the participants followed by total arsenic analysis of the same. Toxic dose emerging from exposure duration is a nonlinear variable. So, Bayesian estimation of the data for noncancer risk assessment of the variable arsenic consumption was performed. In spite of using arsenic-safe water, we observed arsenic consumption and release. Participants with skin lesions had more arsenic in urine than participants without skin lesions. Future risk for participants without skin lesions was twice due to less arsenic release in urine. For the first time, Bayesian simulation was used to assess noncancer risk on a cohort for a consecutive three-year study. A significant finding was the higher assessed noncancer risk of the participants without skin lesions than the participants with skin lesions.     

主要组织相容性复合体单倍型鸭抗原处理相关转运体单抗的制备

目的制备鸭抗原处理相关转运体(TAP)特异性单抗,为深入利用实验鸭开展免疫学研究提供实验材料。方法利用大肠埃希菌诱导表达主要组织相容性复合体(MHC)单倍型HBW-SPF鸭TAP蛋白肽结合区片段,表达产物经镍柱纯化后免疫BALB/c小鼠,采用ELISA技术筛选特异性单抗分泌杂交瘤细胞株。将阳性细胞株制备小鼠腹水,作为一抗,与多次截短表达TAP蛋白肽结合区进行蛋白免疫印迹试验,鉴定单抗针对的抗原表位。通过间接免疫荧光试验比较该单抗对实验鸭和鸡外周血淋巴细胞的反应性,利用免疫组织化学技术检测对SPF鸡、SPF鸭、鹌鹑、鹅和SPF猪的特异性。结果获得一株鸭TAP单抗1A6,抗原表位位于²⁹⁷NARHQMLQQAVLDATAGTGMVVQEAI³²²,对鸡和鸭外周血淋巴细胞具有免疫荧光反应性;在鸡和鸭的肠黏膜固有层检测到大量特异性信号,在猪、鹌鹑和鹅没有检测到信号。结论获得了一株具有鸡和鸭反应性的抗原转运相关体特异性的单抗,可运用于禽类实验动物在禽病学和禽免疫学方面的研究。