大绒鼠幼仔的生长发育和产热特征

为阐明大绒鼠幼仔的生长发育和代谢产热特征,本实验测定了1-49 日龄大绒鼠幼仔的体重、体温、静止代谢率(RMR)和非颤抖性产热(NST)。依据逻辑斯蒂曲线的拐点(24 d),大绒鼠的体重生长可划分为加速生长相和减速生长相,幼仔的体温在19 日龄前逐渐升高,22 日龄时接近成体水平;RMR 和NST分别在28日龄、19日龄前随日龄逐渐增加,RMR 在28日龄时接近成体水平,BAT 产热活性在7 日龄内被激活。结果表明,大绒鼠胎后发育及产热能力符合晚成性动物的一般特征,即具有短的妊娠期,较少的胎仔数,较长的哺乳期,这些特征对适应横断山特殊多变的环境条件具有重要意义。     

高山姬鼠幼仔的生长发育和产热特征

根据高山姬鼠幼仔56 d 的生长资料初步分析了其生长发育规律;用电子天平测量了体重的增长过程; 用开放式呼吸仪测定了静止代谢率(Resting metabolic rate,RMR)、非颤抖性产热(Nonshivering thermogenesis, NST)以及肺皮蒸发失水(Evaporative water loss,EWL)。依据逻辑斯蒂曲线的拐点,高山姬鼠的体重生长可划分为加速生长相和减速生长相。幼仔的体温在17 日龄前逐渐升高,35 日龄时接近成体水平;静止代谢率和非颤抖性产热在17 日龄前随日龄逐渐增大,17 日龄后与体重成异速增长关系,RMR 在49 日龄时接近成体水平,NST 在6 日龄内即被激活;蒸发失水在断乳前较断乳后为高。高山姬鼠为典型的晚成性发育动物。高山姬鼠较短的妊娠期、较大的胎仔数、较长的哺乳期与其食物资源较丰富有关。     

哺乳期棕色田鼠对非亲缘幼仔的行为反应

通过观察产后2 日(L2)、6 日(L6)、10 日(L10)、14 日(L14)和20 日(L20)的棕色田鼠母鼠对2 日龄、6 日龄、10 日龄和14 日龄非亲缘幼仔的攻击行为和衔回行为,探讨了哺乳期棕色田鼠的母性行为与非亲缘幼仔的发育(日龄或个体大小)及母鼠产后时间的关系。结果表明,在哺乳前期(L2,L6),非亲缘幼仔的日龄大小显著影响母鼠的攻击行为(P < 0.05);在哺乳中期(L10,L14)及后期(L20),非亲缘幼仔的日龄对母鼠的攻击行为没有显著影响(P > 0. 05)。在整个哺乳期,母鼠对14 日龄非亲缘幼仔的攻击频次最高(P < 0.05)。产后不同时间的母鼠对同一日龄非亲缘幼仔的攻击频次没有显著差异(P > 0.05)。这些结果表明,哺乳期内的棕色田鼠对非亲缘幼仔的攻击与幼仔的发育有关,与母鼠的产后时间无关。     

亲缘关系与布氏田鼠双亲行为和杀婴行为关系的初探

根据幼仔发育的 5个阶段 :新生 (1～ 5日龄 )、耳立 (6～ 9日龄 )、睁眼 (10～14日龄 )、出巢 (15～ 2 0日龄 )和断奶 (2 1～2 4日龄 ) ,通过观察布氏田鼠对自己幼仔 (r=0 5 0 )和非亲缘幼仔 (r <0 12 5 )的行为反应 ,研究亲缘关系对布氏田鼠双亲和杀婴行为的影响。结果表明 :1)新生阶段 ,雄鼠抚育亲仔的时间显著多于非亲缘幼仔 ;断奶阶段 ,雄鼠与亲仔相触及在巢内活动的时间也显著多于非亲缘幼仔 ;雄鼠在耳立、出巢和断奶阶段嗅闻非亲缘幼仔 ,以及在新生和睁眼阶段修饰非亲缘幼仔的时间都显著多于亲仔。 2 )断奶阶段 ,雌鼠与亲仔相触的时间显著多于非亲缘幼仔 ,但在睁眼阶段修饰非亲缘幼仔 ,以及在新生、耳立和出巢阶段嗅闻非亲缘幼仔的时间显著多于亲仔。 3)雌雄鼠在15日龄前没有杀婴行为 ,15日龄后 ,开始对非亲缘幼仔发生杀婴行为 ;雌鼠杀婴行为受幼仔发育的显著影响 ,且杀婴频次显著高于雄鼠 ;雌鼠在断奶阶段对非亲缘幼仔的杀婴频次显著高于亲仔。综上所述 ,亲缘关系对布氏田鼠的双亲和杀婴行为有显著影响 ,这可能与个体间的已往经历 (熟悉性等 )或表现性匹配等辨别机制有关。     

棕色田鼠幼仔对双亲气味的行为反应

利用双向气味选择实验,观察了10日龄、14日龄、18日龄以及22日龄的棕色田鼠(Lasiopodomys mandarinus)幼仔对双亲底物和陌生鼠底物的行为反应,探讨了幼仔对双亲气味辨别的行为发育。10日龄的幼仔对双亲底物与陌生鼠底物没有显著偏好;14日龄和18日龄的幼仔对双亲底物的访问、嗅闻、滞留和挖掘行为均显著多于陌生鼠底物(P<0.05);22日龄的幼仔对双亲底物的嗅闻和挖掘行为显著多于陌生鼠底物(P<0.05),但对双亲底物与陌生鼠底物的访问和滞留没有显著性差异(P>0.05)。说明棕色田鼠幼仔在断乳前已完全能够辨别双亲气味和陌生气味,但随着日龄增加,22日龄的幼仔对陌生气味的偏好有上升趋势。     

交叉抚育经历对根田鼠体重发育的影响

为检验交叉抚育经历对根田鼠体重发育的可能影响,监测了雌雄亲生和寄养幼仔的体重生长.结果发现: 在不同发育时期(2 ～ 70日龄),雄性亲生与寄养幼仔的体重没有差异; 除第18和20日龄外,其它时期(2 ～ 16,25 ～ 70日龄)雌性亲生与寄养幼仔的体重没有差异; 亲生和寄养幼仔在25日龄前两性体重差异不明显;25日龄后两性体重差异显著; 随着日龄的增加,根田鼠的体重日增长率呈现下降趋势.这些结果表明交叉抚育经历对雄性个体的发育没有影响,对雌性体重发育可能存在短暂影响,但持续时间不长(3 d ≤ T ＜ 9 d);根田鼠亲生和寄养幼仔体重生长的性别差异均在25日龄前后形成.     

布氏田鼠的双亲行为比较

在实验室对布氏田鼠双亲行为和幼仔发育的研究表明, 雌性布氏田鼠的修饰、筑巢和摄食行为显著地多于雄鼠, 且这些差异多集中在幼仔发育的最初9 d 内。雌鼠的修饰、筑巢行为以及在巢内的时间与幼仔发育日龄呈显著地负相关, 而雄鼠的这些行为无显著变化。但雌雄的衔回行为却与幼仔发育日龄呈显著地正相关。据此认为雌性布氏田鼠的双亲行为多于雄鼠, 符合双亲投资的理论。     

人工辅助大熊猫母兽哺乳幼仔研究

2004年大熊猫母兽“蜀庆”(谱系号480)产仔后,虽能抱仔保温但不会哺乳幼仔,经人工辅助让幼仔吃上母乳,幼仔生长发育良好。本文报道了160天内幼仔吮乳的情况,收集了幼仔日吮乳次数、吮乳时间分布、日吮乳量及其与体重的关系等资料。结果表明:1)人工辅助母兽哺乳是解决性情温顺、母性好、有乳汁,但不会哺乳的母兽哺乳幼仔问题的方法;2)大熊猫幼仔每日吮乳次数由1~6前6天的12次左右,逐渐减少并固定在48天后的2次左右;80天内,幼仔吮乳时间在每日的平均分布有4个高峰时间段和4个低谷时间段;3)0~35天间,幼仔日吮乳量(y)与日龄(x)的关系可用公式y=6.2228 x+11.184(R2=0.9258)表示,日吮乳量随日龄增长而呈直线增加,35天后幼仔日吮乳量随日龄增长波动上升;4)幼仔日吮乳量与体重比在1~19天为30.22±1.31%,处于整个育幼期的高水平,之后逐渐下降,95天后稳定在3.92±0.10%的低水平。     

环境温度对不同龄期鸽子热能代谢的影响

本文主要讨论1—25日龄雏鸽及其成鸽在12—36℃环境中的热能代谢。静止代谢是以闭路系统呼吸计测定。产热是据消耗氯气1毫升产热4.7卡计算,即48cal=1毫升氧气。现摘要如下: 1.成鸽在12—36℃环境中的代谢率呈U型曲线,其标准代谢率为1.4333±0.0535 O_2ml/g/hr,中性温度区约18—32℃ 2.雏鸽在22℃与28℃环境,其化学凋温机制建成年龄为8—10日龄。 3.雏鸽的代谢率呈两个相反趋向的年龄相,当化学调温机制建成之前,代谢率与日龄或与体重正相关;而后,负相关。 4.雏鸽在22—28℃环境,4日龄前的代谢率(cal/W 0.67/hr)比成鸽低;5日龄后,则高于成鸽;至化学调温机制建成时,达到最高水平。但是,在36℃环境,却始终低于成鸽水平。     

野化培训大熊猫幼仔第一阶段的活动变化研究

2011年8月—2014年8月,利用红外视频监控系统结合现场观察,在中国保护大熊猫研究中心卧龙核桃坪野化基地对野化培训第一阶段的7只大熊猫Ailuropoda melanoleuca幼仔的活动变化进行研究,采用瞬时扫描取样法收集了母幼距离、幼仔活动空间位置和行为等数据。研究结果发现:(1)母幼距离随着幼仔月龄的增长而增加,到幼仔爬树时母幼距离达到最高点,11~12月龄后出现下降的趋势。(2)野化幼仔随着月龄增长在母兽怀中的时间呈递减趋势;幼仔在地面的时间表现为未能独立活动时递增,5~9月龄时递减,其后14~15月龄时递增的变化规律;幼仔在树上的时间呈现5~10月龄时递增,接着稳定在一个较高的值,到14月龄时递减的波动;幼仔在母兽怀中(n=2,P0.05)和在地面的时间(n=5,P0.01)均与其在树上的时间呈负相关。(3)在活动时间分配上,幼仔平均用于休息的时间为所有行为时间的90.1%±4.1%,平均用于活动的时间为9.3%±3.9%,平均用于觅食的时间为0.6%±0.4%。     

Evidence that the C-terminus of OprM is involved in the assembly of the VceAB-OprM efflux pump

Although the architecture of tripartite multiple drug resistance (MDR) efflux pumps of Gram-negative bacteria has been well characterized, the means by which the components recognize each other and assemble into a functional pump remains obscure. In this study we present evidence that the C-terminal domain of the Pseudomonas aeruginosa OprM and the α-helical hairpin domain of Vibrio cholerae VceA play an important role in the recognition/specificity/recruitment step in the assembly of a functional, VceAB-OprM chimeric efflux pump. To our knowledge, this is the first evidence directly linking the C-terminal domain of an outer membrane efflux protein to its recruitment during the assembly of a tripartite efflux pump.     

心脑血管疾病大额住院消费统计分析

通过对医院2004-2006年心脑血管疾病大额住院消费(消费大于50000元,以下简称大额消费)病例发病率高的前五种疾病的构成情况、药费、材料费消耗情况进行分析,认为加强大额病例中发病率高的病种的重点管理,是降低医疗费用的有效途径。建议制定常见病大额病种预定额付费方案和审查报销制度;采用适宜技术;控制药费,防止过度医疗,有效地遏制医疗费用的过快增长。     

Studies on the energy coupling sites of photophosphorylation IV. The relation of proton fluxes to the electron transport and ATP formation associated with Photosystem II

1. By using dibromothymoquinone as the electron acceptor, it is possible to isolate functionally that segment of the chloroplast electron transport chain which includes only Photosystem II and only one of the two energy conservation sites coupled to the complete chain (Coupling Site II, observed P/e₂ = 0.3–0.4). A light-dependent, reversible proton translocation reaction is associated with the electron transport pathway: H₂O → Photosystem II → dibromothymoquinone. We have studied the characteristics of this proton uptake reaction and its relationship to the electron transport and ATP formation associated with Coupling Site II.

2. The initial phase of H⁺ uptake, analyzed by a flash-yield technique, exhibits linear kinetics (0–3 s) with no sign of transient phenomena such as the very rapid initial uptake (“pH gush”) encountered in the overall Hill reaction with methylviologen. Thus the initial rate of H⁺ uptake obtained by the flash-yield method is in good agreement with the initial rate estimated from a pH change tracing obtained under continuous illumination.

3. Dibromothymoquinone reduction, observed as O₂ evolution by a similar flash-yield technique, is also linear for at least the first 5 s, the rate of O₂ evolution agreeing well with the steady-state rate observed under continuous illumination.

4. Such measurements of the initial rates of O₂ evolution and H⁺ uptake yield an H⁺/e⁻ ratio close to 0.5 for the Photosystem II partial reaction regardless of pH from 6 to 8. (Parallel experiments for the methylviologen Hill reaction yield an H⁺/e⁻ ratio of 1.7 at pH 7.6.)

5. When dibromothymoquinone is being reduced, concurrent phosphorylation (or arsenylation) markedly lowers the extent of H⁺ uptake (by 40–60%). These data, unlike earlier data obtained using the overall Hill reaction, lend themselves to an unequivocal interpretation since phosphorylation does not alter the rate of electron transport in the Photosystem II partial reaction. ADP, P_i and hexokinase, when added individually, have no effect on proton uptake in this system.

6. The involvement of a proton uptake reaction with an H⁺/e⁻ ratio of 0.5 in the Photosystem II partial reaction H₂O → Photosystem II → dibromothymoquinone strongly suggests that at least 50% of the protons produced by the oxidation of water are released to the inside of the thylakoid, thereby leading to an internal acidification. It is pointed out that the observed efficiencies for ATP formation (P/e₂) and proton uptake (H⁺/e⁻) associated with Coupling Site II can be most easily explained by the chemiosmotic hypothesis of energy coupling.     

Strategy for Stabilizing Enzymes Part Two: Increasing Enzyme Stability by Selective Chemical Modification

The molecular mechanisms of change in the thermal stability of proteins modified with low molecular weight reagents are discussed. The choice of stabilization mechanisms to be used as a general strategy for increasing enzyme stability by chemical modification is addressed. Hydrophilization of nonpolar surface areas is the most simple and reliable approach to artificial stabilization of enzymes for use in applied biochemistry and biotechnology.     

Partial purification and properties of Galleria mellonella larvae proteolytic inhibitors acting on Metarhizium anisopliae toxic protease

Gel permeation, preparative isoelectric focusing, and affinity chromatography were used to purify three inhibitors of proteolytic activity from perchloric acid extracts of last instar Galleria mellonella larvae. Electrofocusing experiments revealed three isoinhibitors with different isoelectric points: inhibitor I-1 with p1 of pH 5.6, inhibitor I-2, pH 7.7, and inhibitor I-3 (of small inhibitory activity), pH 8.6. By affinity chromatography on trypsin-Sepharose 4B the I-1 was purified 9.7 ×, but 71.1% of inhibitory activity was lost. Molecular mass of the inhibitory complex was 12,600 Da. I-1 and I-2 are relatively stable to heat at several pHs with minor stability at pH 10. I-1 and I-2 inhibit serine proteases about 2.5 times as much as sulfhydryl proteases. In the same ratio protease P-1 and protease P-2 from Metarhizium anisopliae are inhibited.     

THE DEATH OF BIOETHICS (AS WE ONCE KNEW IT)

Fast forward 50 years into the future. A look back at what occurred in the field of bioethics since 2010 reveals that a conference in 2050 commemorated the death of bioethics. In a steady progression over the years, the field became increasingly fragmented and bureaucratized. Disagreement and dissension were rife, and this once flourishing, multidisciplinary field began to splinter in multiple ways. Prominent journals folded, one by one, and were replaced with specialized publications dealing with genethics, reproethics, nanoethics, and necroethics. Mainstream bioethics organizations also collapsed, giving way to new associations along disciplinary and sub‐disciplinary lines. Physicians established their own journals, and specialty groups broke away from more general associations of medical ethics. Lawyers also split into three separate factions, and philosophers rejected all but the most rigorous, analytic articles into their newly established journal. Matters finally came to a head with global warming, the world‐wide spread of malaria and dengue, and the cost of medical treatments out of reach for almost everyone. The result was the need to develop plans for strict rationing of medical care. At the same time, recognition emerged of the importance of the right to health and the need for global justice in health. By 2060, a spark of hope was ignited, opening the door to the resuscitation of bioethics and involvement of the global community.     

Survival and metabolism of the harpacticoid copepod Thompsonula hyaenae (Thompson) fed on different diatoms

Survival times and oxygen consumption rates have been determined for a benthic harpacticoid copepod, Thompsonula hyaenae (Thompson), when fed different algal diets. Nauplii and adults lived slightly longer on a diet of Navicula sp. than did those fed N. pelliculosa or a mixture of both naviculoid species. Mean numbers of harpacticoids hatched were significantly higher in cultures of N. pelliculosa. Metabolic rates of non-gravid females fed for one week on N. sp. were significantly lower than those fed N. pelliculosa or the mixture. There was no significant difference in oxygen uptake between animals fed N. pelliculosa and those fed the mixed culture. The smaller size and lower food energy content of N. pelliculosa are reflected in the higher respiratory rates of animals led this diatom species.Based on a thesis submitted in partial fulfillment of the M.S. degree in Marine Science at the University of South Carolina. Belle W. Baruch Institute for Marine Biology and Coastal Research Contribution No. 114. Research supported by the Oceanography Section, National Science Foundation, NSF Grant DES72-01573 A01.     

贵州疣螈繁殖生态的研究

贵州疣螈（Tylototritonkweichowensis）是一年繁殖一次的有尾两栖动物。繁殖期肥满度、肝脏系数、脂肪系数、性腺成熟系数、性腺体积均具一定的生物学意义。繁殖期一般为5月上旬至7月上旬,窝卵数平均121．5±7．81枚,孵化期21．6天,孵化率44．33％。每窝印数与雌体头体长成正相关。幼体不同日龄的形态特征变化明显。其全长的Logistic生长方程为：     

用离散量的方法识别蛋白质的超二级结构

用离散量的方法,对2208个分辨率在2.5I以上的高精度的蛋白质结构中四类超二级结构进行了识别。从蛋白质一级序列出发,以氨基酸(20种氨基酸加一个空位)和其紧邻关联共同为参数,当序列模式固定长取8个氨基酸残基时,对“822”序列模式3交叉检验的平均预测精度达到78.1%,jack-knife检验的平均预测精度达到76.7%;当序列模式固定长取10个氨基酸残基时,对“1041”序列模式3交叉检验的平均预测精度达到83.1%,jack-knife检验的平均预测精度达到79.8%。