腰椎旁神经阻滞联合超短波对腰椎间盘突出症患者疼痛及腰背肌生物力学性能的影响

目的:探讨腰椎旁神经阻滞联合超短波对腰椎间盘突出症疼痛及腰背肌生物力学性能的影响。方法:选择我院2014年2月~2016年8月收治的98例腰椎间盘突出症患者,按抽签法分组对照组与研究组。对照组采用腰椎旁神经阻滞治疗,研究组基于对照组加用超短波治疗。观察两组的临床疗效、治疗前后视觉模拟评分(VAS)、60°/s角速、120°/s角速平均功率(AP)、峰力矩(PT)、腰背屈/伸比值(F/E)、血清P物质(SP)、β-内啡肽(β-EP)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平的变化及不良反应的发生情况。结果:研究组总有效率为95.91%,显著高于对照组,差异有统计学意义(P0.05)。治疗后,两组F/E值、血清SP、IL-6、TNF-α水平均较治疗前显著降低,且研究组以上指标均明显低于对照组,两组AP、PT、血清β-EP水平均较治疗前明显上升,且研究组以上指标显著高于对照组,差异均有统计学意义(P0.05)。两组不良反应的发生率比较差异无统计学意义(P0.05)。结论:腰椎旁神经阻滞联合超短波治疗腰椎间盘突出症的效果明显优于单用腰椎旁神经阻滞治疗,其可有效缓解疼痛及改善腰背肌生物力学性能,并减轻炎症反应。     

Response of Chestnut Flowering in Beijing to Photosynthetically Active Radiation Variation and Change in Recent Fifty Years

Climate warming has affected plant phenology throughout the world, but few studies have evaluated plant phenology response to other climate factors (eg. photosynthetically active radiation PAR). In particular, the response of fruit flowering to PAR variation has not been explored yet. Long term (1963-2008) of chestnut (Castanea mollissima Blume) first flowering dates from Beijing, China were related with daily PAR for the 12 months, using Partial Least Squares (PLS) regression analysis. Two relevant phases were identified, during which mean PAR, temperature, and relative humidity (RH) were correlated with flowering dates, respectively. PAR during the both relevant periods decreased significantly in Beijing over the past 50 years. Reduced PAR during 24 September 5 February showed an advance impact on chestnut flowering, and could explain 12% of advance trend in flowering timing. Deceased PAR during 6 February 31 May had a delayed effect on tree flowering, but it was not significant enough to reject the null hypothesis of no impact over time. Advanced flowering of chestnut was mainly determined by increasing temperature between 6 February and 31 May which could explain 41% of flowering trend. Relative humidity variation during this period played secondly important role on tree flowering. Considering the interaction among these three climate factors, the impacts of PAR and RH on flowering timing could partially be attributed to the effects of temperature variation.     

西双版纳地区降雨和食物资源可获得程度对犬蝠分娩时机的影响

繁殖是动物权衡不同自然选择压力和自身生理限制的结果。蝙蝠的繁殖受气候(温度、光周期和降雨量)和食物资源等非生物因素影响。本文通过野外调查犬蝠食物资源、设网捕捉和标志重捕的方法研究西双版纳地区降雨、食物资源可获得程度对犬蝠分娩时机的影响。研究发现,随着3 - 8 月降雨量逐渐增加(19.82 -41.13 kg/ m2 ),犬蝠取食的植物种类呈明显的增加趋势(4 - 9 种)。幼蝠捕捉量与植物资源可获得程度呈显著正相关关系(r = 0. 94,P = 0.01)。西双版纳犬蝠虽然具有一年两次动情和分娩的能力,但是绝大多数个体一年只分娩一次,且集中于3 -5 月。犬蝠分娩时机的选择使得幼蝠飞行学习和捕食时间与食物资源可获得程度高峰期相吻合,有利于提高幼体的生存适合度。     

人类基因组单核苷酸多态性和单体型的分析及应用

单核苷酸多态性是人类基因组中最丰富的遗传变异。单体型是指位于一条染色体上或某一区域的一组相关联的SNP等位位点,单体型已经成为近年来人类遗传研究的组成部分。人类基因组单体型图（HapMap）计划的目标就是构建人类DNA序列中多态位点的常见模式,找出代表整个人类基因图谱之中的SNP集合的标签SNP。在复杂性疾病研究中,由多个变异位点组合构成的单体型分析优于单个SNP的分析。文章论述了SNPs、基因型、表现型的定义与HapMap计划的一些情况,综述了单体型的3种推断算法和单体域的不同定义与构建方法,同时介绍了标签SNP的选择及单体型与复杂疾病关联分析的方法,可利用公共SNP数据库的情况以及SNPs与单体型在复杂疾病与药物反应方面的应用。     

Network structural properties mediate the stability of mutualistic communities

Key advances are being made on the structures of predator–prey food webs and competitive communities that enhance their stability, but little attention has been given to such complexity–stability relationships for mutualistic communities. We show, by way of theoretical analyses with empirically informed parameters, that structural properties can alter the stability of mutualistic communities characterized by nonlinear functional responses among the interacting species. Specifically, community resilience is enhanced by increasing community size (species diversity) and the number of species interactions (connectivity), and through strong, symmetric interaction strengths of highly nested networks. As a result, mutualistic communities show largely positive complexity–stability relationships, in opposition to the standard paradox. Thus, contrary to the commonly-held belief that mutualism's positive feedback destabilizes food webs, our results suggest that interplay between the structure and function of ecological networks in general, and consideration of mutualistic interactions in particular, may be key to understanding complexity–stability relationships of biological communities as a whole.     

Foldon-guided self-assembly of ultra-stable protein fibers

A common objective in protein engineering is the enhancement of the thermodynamic properties of recombinant proteins for possible applications in nanobiotechnology. The performance of proteins can be improved by the rational design of chimeras that contain structural elements with the desired properties, thus resulting in a more effective exploitation of protein folds designed by nature. In this paper, we report the design and characterization of an ultra-stable self-refolding protein fiber, which rapidly reassembles in solution after denaturation induced by harsh chemical treatment or high temperature. This engineered protein fiber was constructed on the molecular framework of bacteriophage P22 tail needle gp26, by fusing its helical core to the foldon domain of phage T4 fibritin. Using protein engineering, we rationally permuted the foldon upstream and downstream from the gp26 helical core and characterized gp26-foldon chimeras by biophysical analysis. Our data demonstrate that one specific protein chimera containing the foldon immediately downstream from the gp26 helical core, gp26(1-140)-F, displays the highest thermodynamic and structural stability and refolds spontaneously in solution following denaturation. The gp26-foldon chimeric fiber remains stable in 6.0 M guanidine hydrochloride, or at 80 degrees C, rapidly refolds after denaturation, and has both N and C termini accessible for chemical/biological modification, thereby representing an ideal platform for the design of self-assembling nanoblocks.     

热休克法抑制第一次卵裂实现草鱼雌核发育的细胞学观察

用组织切片方法系统地观察了草鱼卵被经辐射处理的鲤精子激活后进行第一次卵裂的发育过程。实验表明：在24℃孵化水温下草鱼卵在被激活后24min进入第一次卵裂胶期,27－30min处于中期,33min进入后期。由此可知被激活的草鱼卵子在第24min时已经完成染色体的复制,使草鱼卵子雌核染色体人工加倍的最佳时期是在被激活后的27－30min这一时间区段内。此外,用不同热休克温度和不同的热休克强度处理已完成染色体复制的被激活草鱼卵,表明草鱼卵经41℃处理2min可得到较高比例的基因纯合型雌核发育二倍体鱼。     

Age of the Jeju pony (Equus caballus) at first reproduction: potential costs for foals and mothers that first reproduce early in life

In a related paper, we showed that mares that reproduced early in life tended to have higher fecundity because of a decrease in the duration of inter-birth intervals relative to mares that reproduced later in life. However, we know that young mares are subordinate to older mares. Hence, costs associated with low dominance rank might offset the benefits of earlier reproduction. We compared harassment of foals of female Jeju ponies that first reproduced at three years of age with that of foals of females that first reproduced at five years of age. As a consequence of their positions in the linear dominance hierarchy, foals born to and guarded by young mares were harassed more frequently than foals whose mothers were older when they first reproduced. A mare that reproduced early in life guarded her offspring more closely and intervened between her foal and neighboring mares more frequently than those mares which first reproduced when older. This need to guard their foals and the harm that might ensue from frequent harassment might counter-balance selection towards earlier reproduction in mares.     

Martin Gibbs and the peaceful uses of nuclear radiation, <Superscript>14</Superscript>C

This abstract is a prologue to this paper. Prior to his health failing, Martin Gibbs began writing remembrances of his education and beginning a science career, particularly on the peaceful uses of nuclear radiation, at the U.S. Brookhaven National Laboratory (BNL), Camp Upton, NY. Two years before his death Martin provided one of us (Govindjee) a draft text narrating his science beginnings in anticipation of publication in Photosynthesis Research. Govindjee edited his draft and returned it to him. Later, when it became difficult for him to complete it, he phoned Govindjee and expressed the desire that Govindjee publish this story, provided he kept it close to his original. Certain parts of Martin’s narrations have appeared without references (Gibbs 1999). The Gibbs family made a similar request since the narrations contained numerous early personal accounts. Clanton Black recently presented an elegant tribute on Martin Gibbs and his entire science career (Black 2008). Clanton was given the draft, which he and Govindjee then agreed to finish. This chronicle is their effort to place Gibbs’s narrations about his education and his maturation scientifically, in context with the beginnings of biological chemistry work with carbon-14 at the BNL (see Gibbs 1999). Further, these events are placed in context with those times of newly discovered radioisotopes which became available as part of the intensive nuclear research of World War II (WW II). Carbon-14, discovered during WW II nuclear research in 1940, was extremely useful and quickly led to the rapid discovery of new carbon metabolism pathways and biochemical cycles, e.g., photosynthetic carbon assimilation, within a decade after WW II.