Spatial resolution and location impact group structure in a marine food web

Ecological processes in food webs depend on species interactions. By identifying broad‐scaled interaction patterns, important information on species' ecological roles may be revealed. Here, we use the group model to examine how spatial resolution and proximity influence group structure. We examine a data set from the Barents Sea, with food webs described for both the whole region and 25 subregions. We test how the group structure in the networks differ comparing (1) the regional metaweb to subregions and (2) subregion to subregion. We find that more than half the species in the metaweb change groups when compared to subregions. Between subregions, networks with similar group structure are spatially related. Interestingly, although species overlap is important for similarity in group structure, there are notable exceptions. Our results highlight that species ecological roles vary depending on fine‐scaled differences in the patterns of interactions, and that local network characteristics are important to consider.     

Calibration of MTT assay in proton beams using radiochromic films

PurposeThis study provides methodology of calibrating as well as controlling the output for an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric assay irradiated in a low energy proton beam using EBT3-model GAFCHROMIC^TM film, without correcting for quenching effect.MethodsA calibrated Markus ionization chamber was used to measure the depth dose and beam output for 26.5 MeV protons produced by a CS30 cyclotron. A time-controlled aluminum cylinder was added in front of the horizontal beam-exit serving as a radiation shutter. Following the TRS-398 reference dosimetry protocol for proton beams, the output was calibrated in water at a reference depth of 3 mm. EBT3 film was calibrated for doses up to 8 Gy at the same depth. To verify the dose distribution for each 96-well MTT assay plate, EBT3 film was placed at the reference depth during irradiation and cell doses were scaled by measured percent depth dose (PDD) data.ResultsThe radiochromic film dosimetry system in this study provides dose measurements with an uncertainty better than 3.3% for doses higher than 1 Gy. From a single exposure and utilizing the Gaussian shape of the beam, multiple dose points can be obtained within different wells of the same plate ranging from 6.9 Gy (sigma ∼4%) in the central well, and 2 Gy (sigma ∼8%) for wells positioned closer to the periphery.ConclusionsWe described a methodology for radiochromic film-based dose monitoring system, using low-energy protons, which can be used for the MTT assay in any proton beam, except within Bragg peak region.     

Lower limb kinematics in individuals with chronic low back pain during walking

Several investigators have suggested the presence of a link between Chronic Low Back Pain (CLBP) and lower limbs kinematics that can contribute to functional limitations and disability. Moreover, CLBP has been connected to postural and structural asymmetry. Understanding the movement pattern of lower extremities and its asymmetry during walking can provide a basis for examination and rehabilitation in people with CLBP. The present study focuses on lower limbs kinematics in individuals with CLBP during walking. Three-dimensional movements of the pelvic, hip, knee and ankle joints were tracked using a seven-camera Qualysis motion capture system. Functional dada analysis (FDA) was applied for the statistical analysis of pelvic and lower limbs motion patterns in 40 participants (20 CLBP and 20 controls). The CLBP group showed significantly different hip motion pattern in the transvers plane, altered knee and ankle motion pattern in the sagittal plane on the dominant side and different hip motion pattern in the transvers and frontal planes on the non-dominant side in comparison with the control group over the stance phase. In terms of symmetry, in the CLBP group, hip and knee moved through a significantly different motion patterns in the transvers plane on the dominant side in comparison with the non-dominant side. In the control group, knee moved through a significantly different motion pattern in the transvers plane on the dominant side in comparison with the non-dominant side. In conclusion, low back pain lead to altered movement patterns of the main joints of lower limbs especially on the dominant side during stance phase. Therefore, care should be taken to examine dominant lower limb movement pattern in CLBP to make a better clinical decision.     

三裂叶薯NBS-LRR类抗病基因的筛选鉴定与结构分析

为发掘甘薯近缘野生种三裂叶薯(Ipomoea triloba)的NBS-LRR类抗病基因,从基因数据库中对三裂叶薯基因组序列进行了筛选、鉴定和分析。结果表明,从三裂叶薯的98 025个基因中,筛选到282个编码NBS-LRR类蛋白的基因,其中N型80个,NL型83个,CN型28个,CNL型57个,TN型10个,TNL型23个,RN型1个。三裂叶薯的16条染色体上均含有NBS-LRR家族基因,数量最多的染色体含有65个,最少的只有1个。三裂叶薯基因组共有55个基因簇,包含了63.5%的NBS-LRR家族基因。在NBS-LRR抗病基因家族中,CNL和TNL亚家族分别对应到7和11个保守结构域。这为三裂叶薯抗性资源的利用提供了科学参考。     

癔球症患者食管测压结果、心理特征分析及小剂量阿米替林的干预效果研究

摘要 目的：分析患者的食管测压结果、心理特征及小剂量阿米替林的干预效果。方法：选取2017年5月~2019年5月期间上海市静安区市北医院收治的癔球症患者137例（癔球症组）,另选取同期到上海市静安区市北医院体检的健康志愿者50例（非癔球症组）,比较两组食管测压结果、癔球症症状评分量表（GETS）评分、汉密尔顿抑郁量表-17（HAMD-17）评分、汉密尔顿焦虑量表-14（HAMA-14）评分。按随机数字表法将癔球症患者分为对照组（n=68）和研究组（n=69）,对照组给予常规治疗,研究组则在对照组的基础上联合小剂量阿米替林干预。比较对照组、研究组的临床疗效、不良反应。结果：癔球症组、非癔球症组患者食管上括约肌（UES）长度、UES残余压、食管下括约肌（LES）静息压、收缩前沿速度（CFV）、远端潜伏时间（DL）组间比较差异无统计学意义（P>0.05）;癔球症组患者UES静息压高于非癔球症组（P<0.05）。癔球症组患者GETS、HAMA-14、HAMD-17评分高于非癔球症组（P<0.05）。研究组治疗后的临床总有效率为84.06%（58/69）,高于对照组的66.18%（45/68）（P<0.05）。两组不良反应发生率比较差异无统计学意义（P>0.05）。结论：相对于非癔球症患者,癔球症患者具有较高的UES静息压,癔球症症状及较为严重的不良情绪,采用小剂量阿米替林对癔球症进行干预可提高治疗有效率,用药安全性较好。     

Prenatal exposure to polycyclic aromatic hydrocarbons could increase the risk of low birth weight by affecting the DNA methylation states in a Chinese cohort

Polycyclic aromatic hydrocarbons (PAHs), as a kind of endocrine disruptors, can enter the fetus body cross the placental barrier from prenatal PAHs exposure to cause adverse birth outcomes. However, it is controversial association between prenatal PAHs exposure and low birth weight (LBW) of their infants. So the present study aimed to estimate the effects of prenatal PAHs exposure during the pregnancy on the risk of LBW in a Chinese cohort through modifying the DNA methylation states. A longitudinal prospective study with 407 pregnant women was established from May to October 2019. The prenatal PAHs exposure during the pregnancy was assessed using the internal dose such as the PAHs metabolites and PAH-DNA adducts in the umbilical cord blood. The methylation levels of genomic DNA and growth-related genes (IGF1 and IGF2) were assessed, while the expressions of these genes were both determined by RT-PCR and Elisa methods. The growth outcomes and relevant Z-scores were recorded at birth. The correlations between the DNA methylation status and concentrations of PAHs, expression levels of growth-related genes and body weight/WAZ were investigated as the measures. According to the PAH-DNA adducts, the subjects were divided into two groups: PAHs-exposed group (PAH-DNA adducts>0, n = 55) and non-exposed group (PAH-DNA adducts = 0, n = 352). Compared with the non-exposed group, it displayed marked decreased birth weight, and increased concentrations of PAHs and DNA methylation levels of the global genomic, IGF1 and IGF2 with their lower expressions in the PAHs-exposed group. These hypermethylation (global genomic, CpG14 and CpG15 of IGF1, and CpG14 of IGF2) were positively correlated with the contents of PAHs in the umbilical cord blood, and negatively correlated with the growth outcomes and their expressions. Totally, prenatal PAHs exposures may contribute to an increased risk of LBW of their infants by modulating the DNA methylation states of genomic DNA and growth-related genes (IGF1 and IGF2) in the umbilical cord blood, which could provide the prenatal prevention of PAHs exposure from possible environmental media except from the occupation and tobacco usage to ensure the health of their infants.     

他汀类药物对中老年男性冠心病患者肠道菌群的影响

目的探讨他汀类药物对中老年男性稳定型冠心病患者肠道菌群的影响,为临床冠心病的二级预防提供参考。方法选择64例经皮冠状动脉介入治疗术后坚持服用中等强度他汀类药物的男性稳定型冠心病患者为研究对象。患者年龄55～74岁,均不合并糖尿病。根据研究期间患者低密度脂蛋白胆固醇(LDL-C)水平分为血脂未达标组(NSG组,LDL-C≥1.8 mmol/L)与血脂达标组(SG组,LDL-C1.8 mmol/L)。比较两组患者一般临床情况,治疗前后血糖、血脂水平,同时应用16S rRNA测序分析技术对两组患者肠道菌群进行分析。结果两组患者一般临床情况及他汀类药物治疗前患者血糖、血脂水平差异均无统计学意义(均P0.05)。治疗后,NSG组患者总胆固醇、LDL-C、三酰甘油水平均明显高于SG组;同时NSG组患者治疗后空腹血糖水平明显高于治疗前(均P0.05)。Alpha多样性分析显示,NSG组患者肠道菌群多样性低于SG组(P0.05)。LEfSe分析显示,SG组患者肠道Verrucomicrobia、Verrucomicrobiae、Verrucomicrobiales、Verrucomicrobiaceae、Akkermansias、Akkermansia muciniphila、Subdoligranulum和uncultured_Christensenellaceae_bacterium数量明显高于NSG组,而uncultured_Veillonellaceae_bacterium及Prevotella_stercorea的丰度显著低于NSG组。结论中等强度他汀类药物对男性中老年稳定型冠心病患者的疗效与肠道菌群存在一定关系,主要表现为治疗后LDL-C未达标者肠道脂代谢有益菌Akkermansia muciniphila及Subdoligranulum丰度明显减少。