DCE-MRI联合DWI对直肠癌患者术前T、N分期及系膜淋巴结良恶性的诊断价值

摘要 目的：探讨动态对比增强磁共振(DCE-MRI)联合弥散加权成像（DWI）诊断直肠癌术前T、N分期和系膜淋巴结良恶性的价值。方法：收集2017年2月至2019年10月中国医科大学附属本溪中心医院和中国医科大学附属盛京医院接诊的80例直肠癌患者,均进行常规核磁共振成像（MRI）、DCE-MRI、DWI扫描,获得DCE-MRI、DWI定量参数[转运常数（K ^trans ）、细胞外血管外空间的体积分数（V _e ）、速率常数（K _ep ）、表观扩散系数(ADC)],比较不同T、N分期、不同性质系膜淋巴结DCE-MRI、DWI参数,及其对T、N分期和系膜淋巴结性质的诊断效能。结果：直肠癌癌灶K ^trans 、 K _ep 、V _e 高于正常肠壁,ADC低于正常肠壁（P＜0.05）。TNM分期为T_Ⅲ～Ⅳ期的患者K ^trans 、 K _ep 、V _e 高于T_Ⅰ～Ⅱ期,ADC低于T_Ⅰ～Ⅱ期（P＜0.05）;TNM分期为N₁期的患者K ^trans 、K _ep 、V _e 高于N₀期,ADC低于N₀期（P＜0.05）。联合诊断的灵敏度、特异度、阳性预测值、阴性预测值较高。结论：DCE-MRI联合DWI对直肠癌术前T、N分期、系膜淋巴结性质诊断价值较高。     

不同生育期玉米上草地贪夜蛾的发生为害规律

2019年在广东湛江、江门调查了玉米上草地贪夜蛾Spodoptera frugiperda (Smith)发生为害动态,分析了不同生育期玉米上该虫发生为害差异规律。发现各个地区草地贪夜蛾的虫口数量与玉米受害程度存在较大差异,呈现不均衡性;该虫对玉米苗期为害最严重,其次为大喇叭口期;建立了2个地区玉米6个生育期受害率与虫口数量之间的线性回归模型。研究结果可为草地贪夜蛾监测预警及防控提供参考。     

Lipid status association with 25-hydroxy vitamin D: Cross sectional study of end stage renal disease patients

BackgroundSome observational studies indicate an association of 25-hydroxy vitamin D (25(OH)D) insufficiency and atherogenic cholesterol concentrations. The aim of this study was to investigate relationship between 25(OH)D concentrations and lipid parameters in end stage renal disease (ESRD) patients, separately for predialysis, hemodialysis and peritoneal dialysis patients.MethodsWe have adjusted 25(OH)D concentrations for seasonal variability with cosinor analysis, and performed all further analysis using these corrected 25(OH)D concentrations. Concentrations of 25(OH)D and the lipid parameters were determined in 214 ESRD patients and 50 control group participants. The analysis included the measurement of 25(OH)D by HPLC, apolipoprotein (Apo) AI, ApoB and Lp(a) by nephelometry, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) by spectrophotometry and manually calculated ApoB/ApoAI and LDL-C/HDL-C ratio.ResultsESRD patients with adjusted 25(OH)D concentrations of 50 nmol/L had significantly higher TC (P = 0.005) and ApoAI (P = 0.049). Significantly higher HDLC (P = 0.011) and ApoAI (P = 0.020) were found in hemodialysis patients with the 25(OH)D concentrations of 50 nmol/L. The other analyzed lipid parameters differed significantly between predialysis, hemodialysis and peritoneal dialysis patients with 25(OH)D concentrations of < 50 nmol/L.ConclusionsOur study indicate the significant relationship between 25(OH)D repletion and optimal concentrations of lipid parameters in ESRD patients. Further research is necessary to explain whether joint evaluation of vitamin D status and lipid abnormalities could improve cardiovascular outcome in ESRD patients.     

Anoxia can increase the rate of decay for cnidarian tissue: Using Actinia equina to understand the early fossil record

An experimental decay methodology is developed for a cnidarian model organism to serve as a comparison to the many previous such studies on bilaterians. This allows an examination of inherent bias against the fossilisation of cnidarian tissue and their diagnostic characters, under what conditions these occur, and in what way. The decay sequence of Actinia equina was examined under a series of controlled conditions. These experiments show that cnidarian decay begins with an initial rupturing of the epidermis, followed by rapid loss of recognisable internal morphological characters. This suggests that bacteria work quicker on the epidermis than autolysis does on the internal anatomy. The data also show that diploblastic tissue is not universally decayed more slowly under anoxic or reducing conditions than under oxic conditions. Indeed, some cnidarian characters decay more rapidly under anoxic conditions than they do under oxic conditions. This suggests the decay pathways acting may be different to those affecting soft bilaterian tissue such as soft epidermis and internal organs. What is most important in the decay of soft polyp anatomy is the microbial community, which can be dominated by oxic or anoxic bacteria. Different Lagerstätte, even of the same type, will inevitably have subtle difference in their bacterial communities, which among other factors, could be a control on soft polyp preservation leading to either an absence of compelling soft anthozoans (Burgess Shale) or an astonishing abundance (Qingjiang biota).     

大豆滞绿(stay-green)突变体诱变后代表型性状变异分析

本文利用大豆滞绿突变体Z-94320经60Co-γ射线诱变的突变体后代M5、M6代为材料,进行两年的田间性状观察记录统计,用相关性分析、主成分分析、聚类分析对其17个主要表型性状统计分析。结果表明:诱变后代产生了丰富的变异,出现了多种种皮色和子叶色,产生了非滞绿性状,形成了各种生育周期,且分离出晚熟性状。通过相关性分析发现,单株粒重与株重、茎粗、主茎荚数、分枝荚数、一粒荚数、二粒荚数、三粒荚数、瘪粒荚数、虫食数呈极显著正相关,这些性状可以对产量进行预测;主成分分析在M5代提取出“产量因子”、“株型因子”、“粒荚因子”、“茎荚因子”四个主成分,对农艺性状累计贡献率达到70.50%,M6代提取出“产量因子”、“虫害因子”、“株型因子”、“茎杆因子”四个主成分,对农艺性状累计贡献率达到71.54%;聚类分析将M5、M6代材料分别划分为6类,发现同代中各类群农艺性状情况大致相似,但是各农艺性状在两代之间的变化明显,在株重、结荚高度、单株粒重等方面M6代显著高于M5代,并筛选出两株高产品系和一株特色滞绿品系。本研究逐步完善了对滞绿大豆突变体库的构建,为滞绿大豆诱变后代的遗传多样性研究提供了基础的数据分析。     

Spatial synchrony in the response of a long range migratory species (Salmo salar) to climate change in the North Atlantic Ocean

A major challenge in understanding the response of populations to climate change is to separate the effects of local drivers acting independently on specific populations, from the effects of global drivers that impact multiple populations simultaneously and thereby synchronize their dynamics. We investigated the environmental drivers and the demographic mechanisms of the widespread decline in marine survival rates of Atlantic salmon (Salmo salar) over the last four decades. We developed a hierarchical Bayesian life cycle model to quantify the spatial synchrony in the marine survival of 13 large groups of populations (called stock units, SU) from two continental stock groups (CSG) in North America (NA) and Southern Europe (SE) over the period 1971–2014. We found strong coherence in the temporal variation in postsmolt marine survival among the 13 SU of NA and SE. A common North Atlantic trend explains 37% of the temporal variability of the survivals for the 13 SU and declines by a factor of 1.8 over the 1971–2014 time series. Synchrony in survival trends is stronger between SU within each CSG. The common trends at the scale of NA and SE capture 60% and 42% of the total variance of temporal variations, respectively. Temporal variations of the postsmolt survival are best explained by the temporal variations of sea surface temperature (SST, negative correlation) and net primary production indices (PP, positive correlation) encountered by salmon in common domains during their marine migration. Specifically, in the Labrador Sea/Grand Banks for populations from NA, 26% and 24% of variance is captured by SST and PP, respectively and in the Norwegian Sea for populations from SE, 21% and 12% of variance is captured by SST and PP, respectively. The findings support the hypothesis of a response of salmon populations to large climate‐induced changes in the North Atlantic simultaneously impacting populations from distant continental habitats.     

Hirticrusta gen. nov. segregated from Neofomitella in Polyporaceae (Polyporales)

Taxonomic studies including morphological observations and phylogenetic analyses were conducted on Japanese “uragin-take”, an unidentified species from Amazonia, Brazil and their allies. Phylogenetic analyses using ITS, nrLSU and RPB2 regions revealed that “uragin-take”, Neofomitella polyzonata and the unidentified species formed a monophyletic clade separate from the clade including the other four Neofomitella spp. and that “uragin-take” is conspecific with N. polyzonata. Morphological investigations on authentic specimens revealed that Polyporus subradiatus is a prior name for N. polyzonata. We propose Hirticrusta gen. nov. typified by H. subradiata segregated from Neofomitella, and we erected H. amazonica sp. nov. for the unidentified species. Hirticrusta is characterized by annual to biennial and sessile basidiocarps, semicircular to dimidiate pileus, velutinous to tomentose hairs on pileus surface, buff to brown context with a crustose layer indicated by a dark brown line forming a longitudinal section below the superficial hairs, a trimitic hyphal system, crustose layer composed of parallel and densely arranged brown hyphae and cylindrical basidiospores. The new species, H. amazonica is distinguishable from other polypores by downy and long tomentum on the pileus surface (up to 20 mm thick), brown context with a dark brown layer below the tomentum and round pores (5–7/mm).     

基于无人机的冬小麦拔节期表层土壤有机质含量遥感反演

快速监测大面积分布的盐渍化麦田土壤有机质含量,可为推进盐渍土改良和促进碳循环研究提供数据支撑。通过野外采样与获取无人机遥感影像,分别基于裸土和植被情况,采用多元线性回归(MLR)、偏最小二乘回归(PLSR)和支持向量机回归(SVR)3种方法,建立区域有机质含量遥感模型,并进行检验和对比,确定最优的土壤有机质含量反演模型;最后基于最优模型进行研究区表层土壤有机质的反演,并与插值结果进行比较。结果表明: 经5×5的中值滤波处理后的光谱与土壤表层有机质对应最优;3种模型中,SVR模型的预测精度最高,PLSR次之,MLR效果最差。对比两种变量的建模效果,基于植被的SVR建模效果最好,其建模决定系数(R²)、均方根误差(RMSE)分别为0.89、0.20,验证R²、RMSE分别为0.82、0.24;基于裸土的建模效果不理想,最优的也是SVR模型,其建模R²、RMSE分别为0.63、0.26,验证R²、RMSE分别为0.61、0.25。根据最优模型反演得到该区域有机质含量为17.51～22.53 g·kg^-1,平均值为19.51 g·kg^-1,与实地调查结果较为一致;插值结果与反演结果相比,精度受到限制。综上,基于无人机多光谱可以对盐渍土冬小麦拔节期土壤有机质含量进行快速、大范围精准估测。     

河野脂螨发育各阶段外部形态扫描电镜观察

【目的】了解河野脂螨Lardoglyphus konoi各发育阶段外部形态和超微结构特征。【方法】利用室内培养获得的不同发育阶段的河野脂螨个体样本,在扫描电镜下观察各发育阶段(卵、幼螨、若螨和成螨)的外部形态和超微结构。【结果】河野脂螨卵呈椭圆形;幼螨足3对,未见生殖器官生长痕迹,生殖毛和肛毛缺如;若螨足4对,生殖器官发育不完全,有生殖毛和肛毛,但发育亦不完全。休眠体前端尖细,后端钝圆,呈梨形状。在末体区有吸盘板,其上有13个吸盘,呈2-2-4-5分布。成螨螯肢细长,剪刀状,其上的定趾和动趾上有几个小齿;顶外毛长度约为顶内毛的50%,与顶内毛处同一水平线上。雄成螨第3对足的跗节末端为2个粗钝的齿所替代;腹面有1个生殖区和带有1对肛门吸盘的肛区。雌成螨所有的爪均分叉;腹面生殖孔为1个纵向裂缝;肛门不伸达后缘。【结论】通过电镜扫描对河野脂螨不同发育阶段外部形态和超微结构的观察,更加详细地了解了该螨的形态结构,从而为脂螨科螨类的分类和生物学研究提供了理论依据。