新生儿脐血瘦素水平的初步研究

目的:研究脐血瘦素水平与新生儿性别、孕周、出生体重、身高、体重指数及胎盘重量的关系。方法:应用酶联免疫法(ELISA)测定脐血瘦素水平,共测定了46份样本,运用统计学方法分析其与新生儿性别、孕周、出生体重、身高、体重指数BMI(即体重除以身高的平方,单位为kg·m~(-2)及与胎盘重量等的关系。结果:脐血瘦素水平与出生体重、身高、体重指数及胎盘的重量有着显著性相关,而男女性别间脐血瘦素水平无显著性差异。结论:脐血瘦素水平与新生儿孕周、出生体重、身高、体重指数及胎盘重量有密切关系,临床测定脐血瘦素水平对预测胎儿出生体重和生长发育有重要意义。     

Mammal-like muscles power swimming in a cold-water shark

Effects of temperature on muscle contraction and powering movement are profound, outwardly obvious, and of great consequence to survival. To cope with the effects of environmental temperature fluctuations, endothermic birds and mammals maintain a relatively warm and constant body temperature, whereas most fishes and other vertebrates are ectothermic and conform to their thermal niche, compromising performance at colder temperatures. However, within the fishes the tunas and lamnid sharks deviate from the ectothermic strategy, maintaining elevated core body temperatures that presumably confer physiological advantages for their roles as fast and continuously swimming pelagic predators. Here we show that the salmon shark, a lamnid inhabiting cold, north Pacific waters, has become so specialized for endothermy that its red, aerobic, locomotor muscles, which power continuous swimming, seem mammal-like, functioning only within a markedly elevated temperature range (20-30 degrees C). These muscles are ineffectual if exposed to the cool water temperatures, and when warmed even 10 degrees C above ambient they still produce only 25-50% of the power produced at 26 degrees C. In contrast, the white muscles, powering burst swimming, do not show such a marked thermal dependence and work well across a wide range of temperatures.     

36例糖尿病孕妇婴儿围产期资料分析

目的 :探讨糖尿病孕妇婴儿在围产期产前、产时和产后三阶段的保健重点 ,减少围产期并发症的发生。方法 :对1998年 1月 - 1998年 12月出生的 36例糖尿病孕妇婴儿的围产期资料进行总结。结果 :77.7%糖尿病孕妇婴儿的母亲在妊娠2 8- 36周确诊为妊娠期糖尿病。 2 1例在妊娠 37- 38周终止妊娠 ,2 9例采用选择性剖宫产术分娩 ,7例阴道分娩。出生体重≥40 0 0 g10例 ,早产大于胎龄儿 1例 ,畸形 1例。无产伤 ,新生儿窒息 ,新生儿呼吸窘迫综合症及低血糖等并发症。结论 :对糖尿病孕妇早期诊断及治疗 ,适时终止妊娠 ,选择适宜的分娩方式 ,产后对新生儿严密监测及治疗 ,能明显降低围产期并发症     

胎膜早破对新生儿脐血免疫球蛋白及补体的影响

目的:研究胎膜早破时新生儿脐血免疫球蛋白、补体的变化规律。方法:应用速率透射比浊法检测79例新生儿脐血IgG、IgA、IgM和补体C3、C4水平,追踪新生儿出生1周内感染发生的情况,其中有胎膜早破史的研究组38例,无胎膜早破史的对照组41例。结果:胎膜早破组脐血IgA(0.16±0.12)g/L,对照组(0.06±0.03)g/L,(P<0.01);胎膜早破组IgM(0.24±0.15)g/L,对照组(0.16±0.03)g/L,(P<0.01),差异有统计学意义;脐血IgG水平无明显变化;脐血IgA浓度在胎膜早破72h为0.234±0.156)g/L,较胎膜早破<12h的0.091±0.047g/L明显增加,差异有统计学意义(P<0.05);脐血补体C3(0.76±0.35)g/L,对照组(0.93±0.21)g/L,(P<0.05),C4(0.16±0.09)g/L,对照组0.20±0.05g/L,(P<0.05),研究组明显低于对照组,差异有统计学意义。结论:有胎膜早破史的新生儿,脐血免疫球蛋白IgA、IgM浓度升高,IgG不受胎膜早破的影响,脐血补体C3、C4水平下降。脐血IgA、IgM及补体C3、C4均能反映胎膜早破个体合并宫内感染。     

The role of autophagy during the early neonatal starvation period

At birth the trans-placental nutrient supply is suddenly interrupted, and neonates face severe starvation until supply can be restored through milk nutrients. Here, we show that neonates adapt to this adverse circumstance by inducing autophagy. Autophagy is the primary means for the degradation of cytoplasmic constituents within lysosomes. The level of autophagy in mice remains low during embryogenesis; however, autophagy is immediately upregulated in various tissues after birth and is maintained at high levels for 3-12 h before returning to basal levels within 1-2 days. Mice deficient for Atg5, which is essential for autophagosome formation, appear almost normal at birth but die within 1 day of delivery. The survival time of starved Atg5-deficient neonates (approximately 12 h) is much shorter than that of wild-type mice (approximately 21 h) but can be prolonged by forced milk feeding. Atg5-deficient neonates exhibit reduced amino acid concentrations in plasma and tissues, and display signs of energy depletion. These results suggest that the production of amino acids by autophagic degradation of 'self' proteins, which allows for the maintenance of energy homeostasis, is important for survival during neonatal starvation.     

Evaporation in the young solar nebula as the origin of 'just-right' melting of chondrules

Chondrules are millimetre-sized, solidified melt spherules formed in the solar nebula by an early widespread heating event of uncertain nature. They were accreted into chondritic asteroids, which formed about 4.56 billion years ago and have not experienced melting or differentiation since that time. Chondrules have diverse chemical compositions, corresponding to liquidus temperatures in the range 1,350-1,800 degrees C. Most chondrules, however, show porphyritic textures (consisting of large crystals in a distinctly finer grained or glassy matrix), indicative of melting within the narrow range 0-50 degrees C below the liquidus. This suggests an unusual heating mechanism for chondrule precursors, which would raise each individual chondrule to just the right temperature (particular to individual bulk composition) in order to form porphyritic textures. Here we report the results of isothermal melting of a chondritic composition at nebular pressures. Our results suggest that evaporation stabilizes porphyritic textures over a wider range of temperatures below the liquidus (about 200 degrees C) than previously believed, thus removing the need for individual chondrule temperature buffering. In addition, we show that evaporation explains many chondrule bulk and mineral compositions that have hitherto been difficult to understand.     

不同发育状况早产儿血清胱抑素C的变化及临床意义

目的比较不同发育状况早产儿血清胱抑素C（Cys C）、血肌酐（Scr）及尿素氮（BUN）水平,评价宫内发育迟缓早产儿的肾功能状况。方法选择无出生窒息的33～35周早产儿,根据体重与胎龄的关系分为适于胎龄儿组和小于胎龄儿组,于生后24～36 h采静脉血,以全自动生化分析仪测定血清Cys C、Scr和BUN的含量,并进行组间比较。结果不同发育状况早产儿血清Cys C、Scr和BUN水平均无明显差异。结论未发现宫内发育迟缓早产儿有肾功能损害。     

Effect of temperature on batch elastase production by Bacillus sp. EL31410

The production of elastase by Bacillus sp. EL31410 at various temperatures was investigated. In order to study the effect of temperature on elastase fermentation, different cultivation temperatures, ranging from 39℃ to 28℃, were evaluated in shake flask. The result indicated that 37℃ was best for cell growth at earlier stage; while maximum elastase activity was obtained when the cells were cultivated at 30℃. This result was verified by batch fermentation in 5-L bioreactor under 37 ℃ and 30 ℃ temperature, respectively. The specific cell growth rate at 37 ~C was higher than that at 30 ℃ during earlier stage of cultivation. The maximum value [5.5 U/(h-g DCW)] of elastase formation rate occurred at 24 h at 30℃ compared to 4.6 U/(h-g DCW) at 30 h at 37℃. Based on these results, two-stage temperature shift strategy and oscillatory temperature cultivation mode were evaluated in the next study. When compared to single temperature of 37 ℃ or 30℃, both two-stage temperature shift strategy and oscillatory temperature strategy improved biomass but did not yield the same result as expected for elastase production. The maximum biomass (both 8.6 g/L) was achieved at 30 h at 37℃, but at 42 h using two-stage temperature cultivation strategy. The highest elastase production (652 U/ml) was observed at 30℃ in batch process. It was concluded that cultivation at constant temperature of 30℃ was appropriate for elastase production by Bacillus sp. EL31410.     

龙眼角颊木虱发育起点温度和有效积温的研究

在人工气候室不同温度下测定龙眼角颊木虱的各个虫态及全世代的发育起点温度和有效积温.研究结果表明,在试验温度范围内(18-30℃)龙眼角颊木虱的生命活动能正常进行.发育历期随温度的升高而缩短,随温度的降低而延长;在18℃时从卵发育到成虫需72.76d,在30℃时从卵发育到成虫需31.76d.龙眼角颊木虱室内人工饲养温度以24-30℃范围内发育历期最短,发育速度最快.全世代的理论发育起点温度C为6.966±2.0142(℃),有效积温K为770.224土88.2071(日度).根据在福州全年大于发育起点温度的有效积温约为4550日·度;计算出龙眼角颊木虱在福州地区一年发生的理论代数为5.91代,这与田间实际发生代数6代基本吻合.为龙眼角颊木虱在福州地区发生提供了预测依据,为化学防治发挥重要的指导作用.     

双胎妊娠149例临床分析

目的：探讨双胎妊娠并发症的防治及最佳分娩方式．方法：对我院2003年1月至2006年12月期间住院分娩的149例双胎妊娠病例进行回顾性分析，并与同期住院分娩的8921例单胎妊娠做比较．结果：双胎妊娠的发生率为1．64％，妊高征、贫血和早产等发病率显著高于单胎妊娠，出生孕周及体重是影响围产儿预后的主要因素，经阴道分娩的双胎妊娠围产儿死亡率明显高于剖宫产者．结论：积极预防和治疗双胎妊娠并发症，选择合适的分娩时机和分娩方式对于降低双胎妊娠的围产儿病死率有重要意义．     

鹿茸对孕鼠和胎鼠的影响

目的本实验旨在探究鹿茸对孕鼠和胎鼠的影响。方法昆明小鼠随机分组,A组：早48只,6 24只以6：9 =1：2的比例合笼,孕第5天一第14天连续对雌鼠经口灌胃给3 mg·kg。1d～、6 mg·kg“d“和12 mg·kg。d’1剂量 的鹿茸;B组：早96只,6 48只,雄鼠连续给鹿茸(剂量同A组雌鼠)60 d后,以6：辛=l：2的比例合笼,从受孕率、 孕鼠体重、死胎率、吸收胎率、胎盘重、子宫和胎鼠重以及胎鼠的外观、内脏和骨骼等方面进行检查。结果A组： 在第18天时,高剂量组体质量、死胎率、吸收胎率、胎鼠外观、内脏和骨骼畸形率与对照组比较,具有统计学意义(P <0．05);随剂量的升高,胎盘重、子宫和胎鼠重有所降低．但没有统计学意义。B组：中剂量组与对照组之间比较, 受孕率显著增加,具有统计学意义(P<0．05);随着剂量的增加各组死胎率、吸收胎率、胎盘重、子宫和胎鼠重无显 著差异(P>0．05);各给药组与对照组比较,对胎鼠畸形没有造成影响。结论在本实验剂量范围内,高剂量组鹿 茸在雌鼠妊娠期间可导致孕鼠体质量下降,死胎率、吸收胎率增加;胎鼠外观、内脏和骨骼畸形增加;中剂量鹿茸在 交配前对雄鼠灌胃可提高受孕率,对胎鼠不造成畸形。     

Study on the comprehensive combustion kinetics of MSW

The combustion behavior of typical components of MSW was examined with a thermal gravimetric analyzer (TGA). The experiments were done over the temperature range of room temperature to 1000 degrees C at a heating rate of 10 degrees C/min and in an oxidizing atmosphere. The results indicated that the entire weight loss process of each typical component of MSW consists of one to three distinct combustion stages. The combustion of typical components of MSW could be modeled by one to three independent reactions. The corresponding parameters of typical components of MSW such as activation energy, pre-exponential factor, and reaction order were determined. The calculated results using the comprehensive kinetic model composed of one to three independent and consecutive reactions, agreed well with experimental results.     

Low-latitude seasonality of Cretaceous temperatures in warm and cold episodes

The Cretaceous period is generally considered to have been a time of warm climate. Evidence for cooler episodes exists, particularly in the early Cretaceous period, but the timing and significance of these cool episodes are not well constrained. The seasonality of temperatures is important for constraining equator-to-pole temperature gradients and may indicate the presence of polar ice sheets; however, reconstructions of Cretaceous sea surface temperatures are predominantly based on the oxygen isotopic composition of planktonic foraminifera that do not provide information about such intra-annual variations. Here we present intra-shell variations in delta18O values of rudist bivalves (Hippuritoidea) from palaeolatitudes between 8 degrees and 31 degrees N, which record the evolution of the seasonality of Cretaceous sea surface temperatures in detail. We find high maximum temperatures (approximately 35 to 37 degrees C) and relatively low seasonal variability (< 12 degrees C) between 20 degrees and 30 degrees N during the warmer Cretaceous episodes. In contrast, during the cooler episodes our data show seasonal sea surface temperature variability of up to 18 degrees C near 25 degrees N, comparable to the range found today. Such a large seasonal variability is compatible with the existence of polar ice sheets.     

非营养性吸吮和抚触对低体重新生儿胃肠道发育的影响

目的探讨非营养性吸吮和抚触对低体重新生儿胃肠道发育的影响。方法将120例低体重新生儿随机分为4组：胃管喂养（A组）、胃管喂养结合非营养性吸吮（B组）、胃管喂养结合抚触（C组）、胃管喂养结合非营养性吸吮和抚触（D组）,每组30例。记录每次喂养前抽吸胃内残留奶量、每日排便次数、每Et排便量、胎粪排尽时间、黄疸持续时间、出生时体重、生后7天与14天体重的变化。结果每日平均胃残留奶量、胎粪排尽时间、黄疸持续时间,D组均小于其它各组（P〈0．05）;平均日排便次数、平均日排便量、生后7天与14天体重D组均大于其它各组（P〈0．05）。结论非营养性吸吮结合抚触可在一定程度上促进低体重新生儿胃肠道发育。     

Physiology: hibernation in a tropical primate

The Madagascan fat-tailed dwarf lemur, Cheirogaleus medius, hibernates in tree holes for seven months of the year, even though winter temperatures rise to over 30 degrees C. Here we show that this tropical primate relies on a flexible thermal response that depends on the properties of its tree hole: if the hole is poorly insulated, body temperature fluctuates widely, passively following the ambient temperature; if well insulated, body temperature stays fairly constant and the animal undergoes regular spells of arousal. Our findings indicate that arousals are determined by maximum body temperatures and that hypometabolism in hibernating animals is not necessarily coupled to a low body temperature.     

“阳光体育运动”背景下湖北省汉族大学生体质健康现状的调查研究

为了解推行＂阳光体育运动＂以来汉族大学生的体质是否改善,采用频数统计、t检验等数理统计法对1646名19～22岁汉族大学生进行测试,结果表明：1）大学生正常体重组比例较低,低体重现象严重;此外,随年龄增长,男生营养不良、较低体重的比例逐年下降,正常体重比例逐年上升,女生与此相反;2）大学生身体机能均处于良好水平;3）大学生下肢力量仅处于及格水平,男生柔韧性处于及格水平,但女生处于良好水平;4）城乡比较发现,乡村男生的身体机能与素质均显著优于城市男生（P〈0.05）,乡村女生仅柔韧性显著高于城市女生（P〈0.05）;5）性别比较发现,男生身体机能、下肢力量显著高于女生（P〈0.001）,但女生柔韧性显著高于男生（P〈0.001）.这提示湖北省汉族大学生的身体形态、下肢力量急待于进一步改善和提高。     

TRPV3 is a calcium-permeable temperature-sensitive cation channel

Transient receptor potential (TRP) proteins are cation-selective channels that function in processes as diverse as sensation and vasoregulation. Mammalian TRP channels that are gated by heat and capsaicin (>43 degrees C; TRPV1 (ref. 1)), noxious heat (>52 degrees C; TRPV2 (ref. 2)), and cooling (< 22 degrees C; TRPM8 (refs 3, 4)) have been cloned; however, little is known about the molecular determinants of temperature sensing in the range between approximately 22 degrees C and 40 degrees C. Here we have identified a member of the vanilloid channel family, human TRPV3 (hTRPV3) that is expressed in skin, tongue, dorsal root ganglion, trigeminal ganglion, spinal cord and brain. Increasing temperature from 22 degrees C to 40 degrees C in mammalian cells transfected with hTRPV3 elevated intracellular calcium by activating a nonselective cationic conductance. As in published recordings from sensory neurons, the current was steeply dependent on temperature, sensitized with repeated heating, and displayed a marked hysteresis on heating and cooling. On the basis of these properties, we propose that hTRPV3 is thermosensitive in the physiological range of temperatures between TRPM8 and TRPV1.     

A thermodynamic explanation for black smoker temperatures

There is a remarkable difference between the maximum temperature of black smoker effluent (350 degrees C-400 degrees C) and the temperature of the solidifying magma which heats it (approximately 1,200 degrees C). It has been suspected for some time that the nonlinear thermodynamic properties of water might be responsible for this discrepancy. Here, we translate this hypothesis into a physical model, by examining the internal temperature structure of convection cells in a porous medium. We demonstrate that, at pressures appropriate to seafloor crust, plumes of pure water form naturally at approximately 400 degrees C for any heat source with temperature greater than approximately 500 degrees C. Higher temperatures are confined to a boundary layer at the base of the convection cell, where the flow is horizontal. The phenomenon is explained analytically using the thermodynamic properties of water, and is illustrated by numerical simulations. Our model predicts the existence of the high-temperature 'reaction zone' found in ophiolites and suggests that vent temperatures will remain steady as magma chambers solidify and cool.     

室温对家兔体温的影响

目的分析不同室温对家兔体温的影响。方法根据2000版《中国生物制品规程》热原实验规程对家兔体温进行测定。结果在一定范围内,随着室温的升高,家兔体温筛选合格率也随之升高,在20℃~21℃时家兔体温筛选合格率最低(43%),而在24℃~25℃时筛选合格率最高(71%);室温在22℃~25℃时,家兔体温在38.5℃~39.0℃这一组构成比均超50%。结论不同室温对家兔体温的变化有影响,在进行热原实验前的家兔筛选时应予以注意。     

Biological activity in the deep subsurface and the origin of heavy oil

At temperatures up to about 80 degrees C, petroleum in subsurface reservoirs is often biologically degraded, over geological timescales, by microorganisms that destroy hydrocarbons and other components to produce altered, denser 'heavy oils'. This temperature threshold for hydrocarbon biodegradation might represent the maximum temperature boundary for life in the deep nutrient-depleted Earth. Most of the world's oil was biodegraded under anaerobic conditions, with methane, a valuable commodity, often being a major by-product, which suggests alternative approaches to recovering the world's vast heavy oil resource that otherwise will remain largely unproduced.