金属对金属全髋关节置换术后体内金属离子对机体的影响

金属对金属全髋假体由于其具有良好的活动度因而被广泛应用全髋关节置换,但是由于金属对金属全髋假体置换术后可以产生大量的钴铬金属离子而使机体内血液尿液中金属离子水平升高,而金属离子水平升高后可能会对机体产生不利影响,本文就金属对金属全髋假体置换术后对机体的影响作一综述。     

金属对金属全髋关节置换术后体内金属离子对机体的影响

金属对金属全髋假体由于其具有良好的活动度因而被广泛应用全髋关节置换,但是由于金属对金属全髋假体置换术后可以产生大量的钴铬金属离子而使机体内血液尿液中金属离子水平升高,而金属离子水平升高后可能会对机体产生不利影响,本文就金属对金属全髋假体置换术后对机体的影响作一综述。     

Cross Talk between Transition Metal Cathode and Li Metal Anode: Unraveling Its Influence on the Deposition/Dissolution Behavior and Morphology of Lithium

Lithium metal batteries (LMBs) combining a Li metal anode with a transition metal (TM) cathode can achieve higher practical energy densities (Wh L^?1) than Li/S or Li/O₂ cells. Research for improving the electrochemical behavior of the Li metal anode by, for example, modifying the liquid electrolyte is often conducted in symmetrical Li/Li or Li/Cu cells. This study now demonstrates the influence of the TM cathode on the Li metal anode, thus full cell behavior is analyzed in a way not considered so far in research with LMBs. Therefore, the deposition/dissolution behavior of Li metal and the resulting morphology is investigated with three different cathode materials (LiNi_0.5Mn_1.5O₄, LiNi_0.6Mn_0.2Co_0.2O₂, and LiFePO₄) by post mortem analysis with a scanning electron microscope. The observed large differences of the Li metal morphology are ascribed to the dissolution and crossover of TMs found deposited on Li metal and in the electrolyte by X‐ray photoelectron spectroscopy, energy‐dispersive X‐ray spectroscopy, and total reflection X‐ray fluorescence analysis. To support this correlation, the TM dissolution is simulated by adding Mn salt to the electrolyte. This study offers new insights into the cross talk between the Li metal anodes and TM cathodes, which is essential, when investigating Li metal electrodes for LMB full cells.     

微生物学教学在知情意行结构中的探索与实践

阐述了认知结构、情感结构、意志结构和行为结构在当代大学生教育的微生物学学科教学中的探索与实践,包括这种体系的发展基础和建立理念,着重强调其在微生物学教学实践中的实施和所反映出的教学效果。具体来说就是用智给予学生知识,全面提高认知基础;用情关怀学生成长,平稳搭建情感桥梁;用爱启迪学生心灵,迅速增强意志动力;用心培养学生能力,充分施展行为表现。在这种"知情意行"结构的渗透下,大学生的素质教育得到了全面提升,使微生物学教学得到学生的充分肯定并取得比较理想的教学效果。     

Bacterial Phage Receptors, Versatile Tools for Display of Polypeptides on the Cell Surface

Four outer membrane proteins of Escherichia coli were examined for their capabilities and limitations in displaying heterologous peptide inserts on the bacterial cell surface. The T7 tag or multiple copies of the myc epitope were inserted into loops 4 and 5 of the ferrichrome and phage T5 receptor FhuA. Fluorescence-activated cell sorting analysis showed that peptides of up to 250 amino acids were efficiently displayed on the surface of E. coli as inserts within FhuA. Strains expressing FhuA fusion proteins behaved similarly to those expressing wild-type FhuA, as judged by phage infection and colicin sensitivity. The vitamin B(12) and phage BF23 receptor BtuB could display peptide inserts of at least 86 amino acids containing the T7 tag. In contrast, the receptors of the phages K3 and lambda, OmpA and LamB, accepted only insertions in their respective loop 4 of up to 40 amino acids containing the T7 tag. The insertion of larger fragments resulted in inefficient transport and/or assembly of OmpA and LamB fusion proteins into the outer membrane. Cells displaying a foreign peptide fused to any one of these outer membrane proteins were almost completely recovered by magnetic cell sorting from a large pool of cells expressing the relevant wild-type platform protein only. Thus, this approach offers a fast and simple screening procedure for cells displaying heterologous polypeptides. The combination of FhuA, along with with BtuB and LamB, should provide a comprehensive tool for displaying complex peptide libraries of various insert sizes on the surface of E. coli for diverse applications.     

Influence of Chronotype,Season, and Sex of Subject on Sleep Behavior of Young Adults

The aim of this study was to investigate whether sex, season, and/or chronotype influence the sleep behavior of university students. Detailed data were collected on activity/rest patterns by wrist actigraphy combined with diaries. Thirty‐four medical students (19 female and 15 male) were monitored by Actiwatch® actometers for 15 consecutive days in May and again in November. The data of a modified Horne and Östberg chronotype questionnaire, which were collected from 1573 female and 1124 male medical school students surveyed in the spring and autumn over an eight‐year period, were evaluated. Actiwatch® sleep analysis software was used to process the activity data with statistical analyses performed with ANOVA. We found no significant sex‐specific differences in sleep efficiency, sleep onset latency, or actual sleep‐time duration. However, we did find a difference in sleep efficiency between morning and evening types, with morning types having a higher sleep efficiency (87.9%, SD=1.3) than evening types (84.3%, SD=0.87%; p=0.007). Seasonal differences were also detected: the actual sleep‐time duration in autumn was significantly longer (mean 6.9 h, SD=0.13 h) than in spring (6.6 h, SD=0.1 h; p=0.013). Evaluation of the chronotype questionnaire data showed that individuals with no special preference for morningness or eveningness (i.e., so‐called intermediates) were most common. The distribution of chronotypes was related to the sex of subject. Men displayed eveningness significantly more often than women (28.9% males vs. 20.8% females; p<0.001), while females exhibited greater morningness (20.3% females vs.15.6% males; p<0.001). Sex influences chronotype distribution, but not actual sleep time‐duration, sleep onset latency, or sleep efficiency. The latter, however, differed among chronotypes, while actual sleep‐time duration was affected by season.     

诱导物和金属离子对竹子白腐菌降解影响的研究

研究了4种诱导物和5种金属离子对白腐菌降解竹子的影响。结果表明这4种诱导物对木质素的降解没有明显的促进作用,低浓度的吐温80抑制纤维素的降解,降解率仅为3．057％;5种离子对木质素降解均有促进作用,一定浓度的离子明显地抑制纤维素的降解,其中Ca^2＋对纤维素降解的抑制作用最强,降解率仅为0．620％;诱导物和离子对半纤维素降解率影响较小;吐温80和Ca^2＋能显著提高半纤维素和木质素的选择系数,其中添加Ca^2＋时半纤维素和木质素选择性系数分别为66．565和49．331,初步显示：部分诱导物和金属离子可以有效影响白腐菌对竹子的选择性降解。     

人参皂苷Rg1对抑郁症大鼠抑郁行为和海马神经元损伤、PKA、PKC的影响

摘要 目的：探讨与分析人参皂苷Rg1对抑郁症大鼠抑郁行为和海马神经元损伤、蛋白激酶A（PKA）与蛋白激酶C（PKC）的影响。方法：抑郁症大鼠48只随机平分为三组-模型组、实验1组、实验2组,每组16只大鼠。实验1组、实验2组每天2次灌胃给药（1 mg/mL、4 mg/mL人参皂苷Rg1）,给药体积为10 mL;模型组以相同方式按体重给予双蒸水。观察与记录鼠抑郁行为和海马神经元损伤、PKA、PKC表达变化情况。结果：实验1组、实验2组治疗第7 d、第14 d的逃避潜伏期都显著低于模型组,实验2组与实验1组相比也显著缩短（P<0.05）。实验1组、实验2组治疗第7 d、第14 d的糖水偏好率高于模型组,实验2组与实验1组相比也显著升高（P<0.05）。实验1组、实验2组治疗第7 d、第14 d的血清5-羟色胺较模型组高,血清皮质酮含量较模型组低,实验2组与实验1组对比也有明显差异（P<0.05）。实验1组、实验2组治疗第7 d、第14 d的海马神经元组织的PKA、PKC蛋白相对表达水平显著低于模型组,实验2组与实验1组相比也显著缩短（P<0.05）。结论：人参皂苷Rg1在抑郁症大鼠的应用能改善抑郁行为,增加糖水偏好率,降低逃避潜伏期,还可提高大鼠的血清5-羟色胺含量,降低血清皮质酮含量,降低海马神经元组织的PKA、PKC蛋白表达水平。     

Wetting of the upper needle surface of Abies grandis: influence of pH, wax chemistry and epiphyllic microflora on contact angles

Wetting of the upper needle surface of Abies grandis Lindl. by aqueous solutions of different pH values was investigated. With increasing needle age, contact angles decreased significantly from about 75° on current-year needles to values lower than 30° on 4-year-old needles. On older needles, contact angles were significantly lower, by more than 10°, when aqueous solutions of pH9-0 were used compared with those of pH3-0. On the surfaces of older needles, contact angle titrations were carried out, contact angles being measured with aqueous solutions covering a pH range from 3.0 to 11.0. Measured titration curves showed clear inflection points around pH 7.0, indicating the existence of ionizable carboxylie groups in the interface between needle surface and atmosphere. The evidence seems convincing that the pronounced pH dependence of wetting is mainly due to the presence and/or activity of epiphyllic micro-organisms, whereas the cuticular wax composition of Abies grandis needles does not appear to contribute significantly to this phenomenon. Thus, the results presented here allow the general conclusion that changes of contact angles measured on leaf surfaces may not always be due to changes in the leaf surface chemistry and/or the fine structure of leaf surface waxes, but may also be due to increased amounts of epiphyllic micro-organisms significantly altering the leaf surface wetting properties.     

Ontogenetic Behavior, Migration, and Social Behavior of Pallid Sturgeon, Scaphirhynchus albus, and Shovelnose Sturgeon, S. platorynchus, with Notes on the Adaptive Significance of Body Color

We conducted laboratory studies on the ontogenetic behavior of free embryos (first life interval after hatching) and larvae (first feeding interval) of pallid and shovelnose sturgeon. Migration styles of both species were similar for timing of migration (initiation by embryos on day 0 after hatching and cessation by larvae on days 12–13 at 236–243 cumulative temperature degree units), migration distance (about 13km), life interval when most distance was moved (embryo), and diel behavior of embryos (diurnal). However, the species differed for two behaviors: movement characteristics of embryos (peak movement rate of pallid sturgeon was only one-half the peak rate of shovelnose sturgeon, but pallid sturgeon continued the lower rate for twice as long) and diel behavior of larvae (pallid sturgeon were diurnal and shovelnose sturgeon were nocturnal). Thus, the species used different methods to move the same distance. Migrating as poorly developed embryos suggests a migration style to avoid predation at the spawning site, but moving from spawning habitat to rearing habitat before first feeding could also be important. Migrants of both species preferred bright habitat (high illumination intensity and white substrate), a behavioral preference that may characterize the migrants of many species of sturgeon. Both species were remarkably similar for swimming height above the bottom by age, and day 7 and older migrants may swim far above the bottom and move far downstream. A migration of 12 or 13 days will probably not distribute larvae throughout the population's range, so an older life interval likely initiates a second longer downstream migration (2-step migration). By day 2, individuals of both species were a black-tail phenotype (light grey body with a black-tail that moved conspicuously during swimming). Aggregation behavior suggests that black-tail is a visual signal used for group cohesion.     

Comparison of Structurally-Related Alkoxide, Amine, and Thiolate-Ligated M (M= Fe, Co) Complexes: the Influence of Thiolates on the Properties of Biologically Relevant Metal Complexes

Mechanistic pathways of metalloenzymes are controlled by the metal ion’s electronic and magnetic properties, which are tuned by the coordinated ligands. The functional advantage gained by incorporating cysteinates into the active site of non-heme iron enzymes such as superoxide reductase (SOR) is not entirely understood. Herein, we compare the structural and redox properties of a series of structurally-related thiolate, alkoxide, and amine-ligated Fe(II) complexes in order to determine how the thiolate influences properties critical to function. Thiolates are shown to reduce metal ion Lewis acidity relative to alkoxides and amines, and have a strong trans influence thereby helping to maintain an open coordination site. Comparison of the redox potentials of the structurally analogous compounds described herein shows that alkoxide ligands favor the higher-valent Fe³⁺ oxidation state, amine ligands favor the reduced Fe²⁺ oxidation state, and thiolates fall somewhere in between. These properties provide a functional advantage for substrate reducing enzymes in that they provide a site at the metal ion for substrate to bind, and a moderate potential that facilitates both substrate reduction and regeneration of the catalytically active reduced state. Redox potentials for structurally-related Co(II) complexes are shown to be cathodically-shifted relative to their Fe(II) analogues, making them ineffective reducing agents for substrates such as superoxide.     

斑块质量对大斑啄木鸟冬季觅食行为的影响

为了解大斑啄木鸟(Dendrocopos major)冬季对食物斑块的利用对策,2011年1月和2012年2～3月,在内蒙古乌拉特前旗的农田防护林中,采用目标动物取样法和全事件记录法,观察了大斑啄木鸟在食物斑块的觅食行为,利用主成分分析方法对斑块质量进行评价,通过比较不同质量斑块中大斑啄木鸟的觅食频次、停留时间、觅食成功频次及觅食成功率等指标,分析斑块质量对其觅食行为的影响。结果显示,在不同质量斑块中大斑啄木鸟的觅食频次、停留时间、觅食成功频次差异都极显著,但觅食成功率差异不显著;除停留时间外,不同性别间觅食差异不显著。大斑啄木鸟的觅食频次、停留时间、觅食成功频次与斑块质量呈显著正相关,觅食成功率与斑块质量相关性不显著。大斑啄木鸟倾向于在质量水平高的斑块觅食,表现为在这些斑块停留时间更长、往返次数更频繁;但觅食成功率不受斑块质量影响,这可能是大斑啄木鸟适应不同觅食环境的一种生存本能。     

Acceptability of Animal-Assisted Therapy: Attitudes toward AAT,Psychotherapy, and Medication for the Treatment of Child Disruptive Behavioral Problems

Animal-assisted therapies (AATs) are not widely promoted in routine mental healthcare but represent a viable treatment option given positive perceptions of pets and growing evidence that animals provide meaningful contribution to psychological wellbeing. Relatively little is known about the general public's attitude toward AATs, especially in relation to more commonly used alternatives. This study compared the acceptability of four different treatment options (AAT, medication, psychotherapy, and no active treatment) for common externalizing behaviors in children. Parents from a community sample (N = 189) were presented with vignettes describing a child with symptoms of an externalizing behavior disorder and were asked to rate the acceptability of the four different treatment options. Participants rated AAT as a highly acceptable form of treatment and more acceptable than no active treatment and medication. However, AAT was rated as less acceptable than psychotherapy. Experiences with animals (both positive and negative) were unrelated to the acceptability of AAT. These findings suggest that AAT is viewed as a highly acceptable form of treatment for common externalizing behaviors and should be more systematically investigated as a treatment for children's mental health problems.     

The effects of acute corticosterone administration on anxiety, endogenous corticosterone, and c-Fos expression in the rat brain

The effects of acute pretreatment of rats with corticosterone (5 and 20 mg/kg, s.c.) on emotional behavior, expression of c-Fos protein in brain structures, and serum concentration of corticosterone were studied to model the short-term glucocorticoid-dependent changes in brain functions. Corticosterone was administered 90 min before training of a conditioned fear reaction (a freezing response), and behavioral, hormonal and immunocytochemical effects were examined 1 day later, on the test day. Pretreatment of rats with corticosterone significantly attenuated the freezing reaction in the conditioned fear test. The effect of the corticosterone was accompanied by a selective enhancement of the aversive context-induced c-Fos expression in some brain structures: the parvocellular and magnocellular neurons of the paraventricular hypothalamic nucleus (pPVN and mPVN), the medial amygdala nucleus (MeA), and the cingulate cortex, area 1 (Cg1), as well as an increase in the concentration of aversive context-induced endogenous serum glucocorticoid, 1.5 h and 10 min after the test session, respectively. It is suggested that the behavioral effects of acute pretreatment of rats with corticosterone could be due to changes in the mnemonic processes in the brain, inhibition of brain corticotropin releasing factor (CRF) synthesis, or stimulation of GABA-A receptor modulating neurosteroids synthesis. It is hypothesized that the enhanced activity of Cg1, MeA, pPVN, and mPVN, and the hypothalamic-pituitary-adrenal axis with concomitant increased serum glucocorticoid concentration, might serve to facilitate active coping behavior in a threatening situation.     

莲花山云南柳莺的孵卵行为

20 0 2年 6～ 7月 ,在甘肃省莲花山自然保护区对云南柳莺的孵卵行为进行了研究。结果表明 ,雌鸟孵卵的日活动期为 (80 0 5± 42 8)min (n =1 5 ) ,每天离巢 (3 2 7± 3 9)次 (n =1 5 ) ,每次离巢时间 (6 6±1 8)min (n =5 99) ,每次坐巢时间 (1 8 4± 9 2 )min (n =5 83 ) ,坐巢率为 (73 1± 1 9) %。雌鸟每次坐巢时间和离巢时间的长度均与气温显著相关。日活动期雌鸟在巢的平均卵温为 3 2 3℃ ,夜晚的平均卵温为3 2 7℃。整个孵卵期卵温在发育临界值 2 8℃以上的时间比例为 92 7%。在孵卵后期卵温有逐渐上升的趋势。     

云南拉市海灰鹤的越冬行为初步观察

2004年10月～2005年3月初步观察了云南拉市海保护区灰鹤(Grus grus)的越冬行为.灰鹤在拉市海的越冬期为175～180 d.10月初至11月下旬为灰鹤在拉市海的"迁入期",11月底至12月底为"过境停留期",1月初至3月中旬为"稳定越冬期",3月中下旬为"迁出期".越冬期日间活动以取食为主,占据了75.53%左右的时间,其次为警戒14.66%、护理5.05%、休息4.49%,4种行为的时间分配在各时间段之间差异极显著.在越冬个体中,家庭单位中的成鹤和幼鹤都是比集群中的个体利用更少的时间取食和更多时间警戒,说明较大的群体规模可以降低个体面临的捕食风险.     

浅斑近微蛛体形大小对交配行为的影响

理论和实验表明体形大小是许多动物择偶的重要信号。体形大小与产卵大小、最终产卵数量、后代适合度等都有着密切的关系,因此动物利用体形大小为信号来择偶可以获得高的生殖利益。目前研究交配行为和体形大小的关系的文献较少,特别在微蛛亚科。本文以浅斑近微蛛为实验材料,在室内研究了体形大小对交配行为的影响。测量了体重,体长,头胸甲与腹部的长和宽,以头胸甲的面积(头胸甲的长与宽的乘积)为变量来表示体形大小。以雄蛛的行为为依据,将其交配行为划分为4个时期:潜伏期、求偶期、插入期和纳精期,并记录了各个时期的持续时间。通过分析,发现了一种微蛛新的交配模式,即可将浅斑近微蛛的插入期分为三个阶段:首先是大约25min长插入期,接着是一个大约15min的中度插入期,最后是一个大约5min的短插入期。结果表明,在本试验条件下,浅斑近微蛛的体形大小对其交配行为的潜伏期、求偶期、插入期和纳精期的持续时间都没有影响,对插入期的3个阶段的长短也没有影响。