Computational study to investigate effect of tonometer geometry and patient-specific variability on radial artery tonometry

Tonometry-based devices are valuable method for vascular function assessment and for measurement of blood pressure. However current design and calibration methods rely on simple models, neglecting key geometrical features, and anthropometric and property variability among patients. Understanding impact of these influences on tonometer measurement is thus essential for improving outcomes of current devices, and for proposing improved design. Towards this goal, we present a realistic computational model for tissue-device interaction using complete wrist section with hyperelastic material and frictional contact. Three different tonometry geometries were considered including a new design, and patient-specific influences incorporated via anthropometric and age-dependent tissue stiffness variations. The results indicated that the new design showed stable surface contact stress with minimum influence of the parameters analyzed. The computational predictions were validated with experimental data from a prototype based on the new design. Finally, we showed that the underlying mechanics of vascular unloading in tonometry to be fundamentally different from that of oscillatory method. Due to directional loading in tonometry, pulse amplitude maxima was observed to occur at a significantly lower compression level (around 31%) than previously reported, which can impact blood pressure calibration approaches based on maximum pulse pressure recordings.     

Response of Soil Bacterial Community Structure to Permafrost Degradation in the Upstream Regions of the Shule River Basin,Qinghai–Tibet Plateau

Permafrost degradation affects soil properties and vegetation, but little is known about its consequent effects on the soil bacterial community. In this study, we analyzed the bacterial community structure of 12 permafrost-affected soil samples from four principal permafrost types, sub-stable permafrost (SSP), transition permafrost (TP), unstable permafrost (UP) and extremely unstable permafrost (EUP), to investigate the effects of vegetation characteristics and soil properties on bacterial community structure during the process of permafrost degradation. Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes were the predominant phyla in all four permafrost soil types. The relative abundance of Proteobacteria decreased in the order SSP > TP> UP > EUP, whereas the abundance of Actinobacteria increased in the order SSP < TP < UP < EUP. Moreover, the Actinobacteria/Proteobacteria ratio increased significantly in the order SSP < TP < UP < EUP along with permafrost degradation, which may be useful as a sign of permafrost degradation. Redundancy analysis (RDA) showed that bacterial communities could be clustered by permafrost types. Analysis of single factors revealed that soil moisture (SM) was the most important factor affecting the bacterial community structure and diversity, followed by soil total nitrogen (STN) and vegetation cover (VC). Partial RDA analysis showed that the soil properties and vegetation characteristics jointly shaped the bacterial community structure. Hence, we can conclude that permafrost degradation, caused by global warming, affects vegetation and soil properties and consequently drives changes in the soil bacterial community structure.     

食品中桔霉素控制方法的研究进展

桔霉素(Citrinin,CIT)是由青霉、曲霉和红曲霉属产生的一种具有肾毒性的真菌毒素。许多食品和饲料中均含有桔霉素,污染范围十分庞大。桔霉素可与其他真菌毒素发生协同作用,如展青霉素(Patulin,PAT)、赭曲霉毒素(Ochratoxin,OTA)等,从而增强其毒性作用,对人及动物健康造成更大的危害。现阶段常用的控制手段主要有物理、化学和生物方法,均取得了一定的成就。本文简单介绍了桔霉素的毒性及污染状况,对桔霉素控制方法的研究进展进行了综述。     

Western blot免疫印迹法检测磷酸化蛋白表达条件优化研究

目的:探讨Western blot免疫印迹法不同转膜方法和不同抗原抗体比例对磷酸化蛋白表达的检测效果。方法:选择肌球蛋白轻链(myosin light chain,MLC)及其磷酸化蛋白作为研究对象,比较半干转印法、湿转法和1:3000、1:5000、1:10000等抗体稀释比例对磷酸化蛋白检测效果的影响。结果:半干转印法(恒压16V,30 min)观察到蛋白信号断续;而同样样品利用湿转法(恒压130 V,1h)检测发现信号连续且强度明显增高;对于磷酸化蛋白,半干转印法无法观察到磷酸化蛋白信号;而同样样品湿转法检测出现连续信号。统一利用湿转方法进行后续蛋白磷酸化检测,当抗体稀释比为1:3000时,结果出现非特异性条带;降低抗体稀释比为1:5000时无非特异性条带,且蛋白信号效果较好;抗体稀释比为1:10000时条带图像出现弥散且背景较高。结论:选择合适的转膜方式和抗原抗体比例有助于磷酸化蛋白表达检测。     

黑水虻幼虫血细胞类型的研究

黑水虻Hermetia illucens(L.)是一种重要的资源昆虫。本文旨在筛选出适合黑水虻血细胞观察的染色方法,明确黑水虻血细胞类型、数量及组成,为黑水虻血细胞免疫研究奠定基础。采用Giemsa和Giemsa-Wright's染色方法和血球计数板法,对黑水虻血细胞染色方法和血细胞数量及形态进行研究。结果表明,甲醇固定4 min,Giemsa-Wright's染液染色9 min、pH 7.2磷酸盐缓冲液分色10 min是黑水虻幼虫血细胞最佳染色方法;黑水虻幼虫血细胞包括原血细胞、浆血细胞、粒血细胞、类绛血细胞、珠血细胞5类;4龄黑水虻幼虫血细胞数量大约为2917个/μL,其中浆血细胞占53.20%±2.78%,粒血细胞占37.49%±3.96%,原血细胞占7.97%±1.51%,类绛血细胞占1.02%±0.24%,珠血细胞占0.62%±0.08%。Giemsa-Wright's染色法为黑水虻幼虫血细胞最佳染色方法,黑水虻幼虫血细胞可分为5类10种。     

环状RNA研究进展

环状RNA(circRNA)是一类内源性非编码RNA(Non-coding RNA;ncRNA),与传统线性RNA不同,它是由反向剪接形成的、没有5'端帽子和3'端多聚腺苷酸尾巴的环状闭合结构。起初人们认为circRNA是错误剪接或者低丰度mRNA转录过程中的副产物,但随着高通量测序技术和生物信息学的发展,越来越多的circRNA已被发现和鉴定。circRNA在哺乳动物细胞中具有内生、丰富、保守、稳定、组织特异性、时空特异性等特点,且亚细胞定位存在差异。大量研究发现它可以通过多种机制参与动物生长发育调控,疾病等的发生和发展。综述了circRNA的发现与形成、特征、作用机制、研究方法及与疾病相关的研究进展,以期为circRNA的进一步研究提供参考。     

六出花属DUS测试性状筛选与评价

以39份六出花品种为试材,对51个候选性状进行观测,比对不同测量方式对花相关数量性状的影响,并同时研究了同品种中外花被片与侧外花被片长度的相关性。结果表明:"花序:花序梗长度"和"花:花梗长度"不满足DUS测试性状要求,最后筛选出43个性状作为DUS测试性状。12个数量性状可分别划分为3~7级;不同观测方式对花相关数量性状具有影响,推荐DUS测试时采用随机观测方式;不同批次的同一品种观测结果部分性状上存在差异;多数品种的中外花被片长度与侧外花被片长度之间呈线性正相关;形态性状的聚类分析结果支持将"花:主色"作为分组性状。     

长尖对齿藓原丝体快速培育的关键影响因子研究

为了给苔藓结皮野外恢复的大规模接种提供丰富种源,本文利用0.1% NaClO（10、15、20、30、45、60、120 s）和0.1% HgCl₂（10、15、20、30、45、60、120 s）两种消毒液,采用Knop、MS和Hoagland 3种培养基,设置5.5、6、6.5、7、7.5、8、8.5七个水平的pH值,通过单因素试验设计方法,测定长尖对齿藓[Didymodon ditrichoides（Broth.）]茎叶体的成活率、原丝体长度和分枝数等指标,探讨影响长尖对齿藓原丝体扩繁的关键因子。结果表明：（1）消毒方式、培养基及pH均对长尖对齿藓茎叶体的成活率、原丝体长度和分枝数有显著影响（P<0.05）,影响大小依次均为消毒方式 > 培养基 > pH;（2）最适合的消毒方式为：0.1% NaClO消毒15~20 s;（3）最适合长尖对齿藓原丝体生长的培养基是Knop和Hoagland培养基;（4）最适合长尖对齿藓原丝体生长的pH是7.5。从而得出快速培育长尖对齿藓原丝体的最佳组合为：0.1% NaClO消毒15~20 s+Hoagland/Knop+pH=7.5。本文的研究结果可以缩短长尖对齿藓生长周期以进行快速繁殖,为苔藓结皮的快速培育以及工程化应用提供一定的借鉴。     

补肾温阳化瘀法对子宫内膜异位症患者子宫内膜腺上皮细胞OPN与MMP-9的影响

目的:探讨补肾温阳化瘀法对子宫内膜异位症患者子宫内膜腺上皮细胞骨桥蛋白(OPN)与基质金属蛋白酶-9(MMP-9)的影响。方法:选择我院2013年4月~2016年4月收治的92例子宫内膜异位症患者,分为对照组与观察组,各46例,对照组行常规西医治疗,观察组行补肾温阳化瘀法治疗,比较两组OPN及MMP-9,雌二醇(E2)、促黄体生成素(LH)、卵泡刺激素(FSH),肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)、白细胞介素-8(IL-8),CD3~+、CD4~+、CD8~+、CD4~+/CD8~+,临床疗效及安全性。结果:治疗后,观察组OPN、MMP-9,TNF-α、IL-6、IL-8,CD8~+低于对照组,观察组CD3~+、CD4~+、CD4~+/CD8~+高于对照组,差异有统计学意义(P0.05)。观察组总有效率高于对照组,不良反应率低于对照组(P0.05)。结论:补肾温阳化瘀法可下调子宫内膜异位症患者子宫内膜腺上皮细胞OPN及MPP-9表达。