库车坳陷克深地区现今地应力场及储层裂缝数值模拟

克深三维区目前处于勘探开发的前期,需要明确地应力场及地下储层裂缝的分布规律,指导开发工作,但该区存在地层埋深大、取心困难、成像测井资料缺乏等实际情况,应力场研究及裂缝预测难度大。利用有限元分析方法,以井点现今地应力值为约束进行了克深三维区现今地应力场的数值模拟,同时建立了应力应变与裂缝参数的定量关系模型,利用古今应力场结合法对克深三维区的裂缝参数进行了预测,模拟结果显示构造高部位和断层带是低应力值区及裂缝的有利发育区。裂缝的数值模拟结果与测井解释结果对比表明,预测结果与实钻吻合度较高,裂缝预测效果较好。     

氨氮胁迫对四鼻须鲤鱼肝脏GST酶活力的影响

实验采用生态毒理学方法,以NH4Cl为实验药物,设置0、50、150和250mg/L实验浓度。通过对野生和养殖群体的四鼻须鲤鱼氨氮对肝脏谷胱甘肽巯基转移酶（GST）活力的影响,比较两个群体抗氨氮能力。结果表明：在相同的氨氮浓度和胁迫时间下,四鼻须鲤鱼养殖群体GST酶活力的变化趋势与野生群体大致相同。除250mg/L浓度组在胁迫5d和10d时,野生群体酶活性略低于养殖群体外,在其余时间点的野生群体酶活性均高于养殖群体,而且,在高浓度氨氮胁迫下,野生群体肝脏的GST酶活性达到峰值的时间比养殖群体更短,显示出较强的抗氨氮能力。     

How to Assess Stress in Reptiles

Stress, as an adaptive response of any animal to a stimulus that presents a threat to homeostasis, can occur in reptiles. Yet, many veterinarians fail to recognize the signs of stress in reptiles. In this article, evaluation of reptile stress has been discussed with a focus on the analysis of behavioral changes, neuroendocrine correlation, and biochemical and physiologic effects in reptiles. If stress can be assessed and treated properly in captive reptiles, their health and well-being can be optimized.     

Azospirillum brasilense mitigates water stress imposed by a vascular disease by increasing xylem vessel area and stem hydraulic conductivity in tomato

Water stress, with its negative consequences on plant growth and survival, can be mitigated by Azospirillum brasilense inoculation. In tomato, A. brasilense delays wilting caused by a vascular pathogen, Clavibacter michiganensis subsp. michiganensis, by yet unknown mechanisms. We studied morphological, anatomical and physiological changes induced by A. brasilense in tomato that relate to water stress tolerance, which could explain the deferral in symptom expression. For this purpose, tomato seeds were treated or not with A. brasilense BNM65, and 5 weeks later plants were challenged with C. michiganensis subsp. michiganensis or mock inoculated with water. There was a large growth promotion associated to Azospirillum: treated plants had higher total biomass and leaf area. In relation to water stress tolerance, Azospirillum treated plants had larger xylem vessel area, higher stem specific hydraulic conductivity, thicker stems, and lower shoot/root dry matter and specific leaf area. These changes were opposite to those induced by C. michiganensis subsp. michiganensis. We conclude that A. brasilense favoured a better adjustment of plant-water relations by several mechanisms, and thus, transitorily alleviated symptoms expression of a vascular disease.     

低温胁迫下草坪草抗寒性的研究进展

通过介绍低温对草坪草的影响和作用机理,系统地综述了在低温胁迫下草坪草的光合特性、水分生理代谢、细胞质膜相对透性、保护酶系变化、碳水化合物贮藏、可溶性蛋白质含量、以及脂肪酸的变化在低温胁迫方面的研究进展,提出了今后进行草坪草抗寒性研究的趋势和建议。     

NaCl胁迫对羽衣甘蓝生理生化指标的影响

试验采用水培种植的方法研究不同NaCl浓度对羽衣甘蓝幼苗光合色素含量、可溶性蛋白质含量、过氧化氢酶(CAT)活性以及过氧化物酶(POD)活性的影响。结果表明:随着NaCl浓度的增加,叶绿素含量总体呈下降趋势;可溶性蛋白质含量、CAT和POD活性随着NaCl浓度的增加先上升后下降;在NaCl浓度为600mmol/L时可溶性蛋白质含量、CAT活性达到最高值,而POD活性则是在NaCl浓度为800mmol/L时达到最高。     

骆驼乳清蛋白对热应激所致大鼠肝氧化损伤的保护作用

本试验旨在研究骆驼乳清蛋白（CWP）对热应激（HS）大鼠肝损伤、氧化应激及肝功能的保护作用。选取6周龄SD大鼠36只,适应性饲养2周后随机分为6组：正常对照组饲喂基础日粮;CWP对照组添加400 mg·kg^-1的CWP;HS组除饲喂基础日粮外,每天进行2 h HS处理,连续8 d;3个CWP干预组分别于每次HS前灌服100、200和400 mg·kg^-1的CWP。试验结束后,取大鼠肝组织,HE染色观察肝组织病理学变化,同时检测肝功能生物标志物、氧化应激标志物水平及抗氧化酶活性。结果表明：CWP降低了HS大鼠血清谷草转氨酶（AST）和谷丙转氨酶（ALT）活性,400 mg·kg^-1的CWP干预效果最好（P<0.01）;400 mg·kg^-1CWP干预组有效降低了HS诱导的大鼠肝组织病理学改变; CWP降低了大鼠肝活性氧（ROS）及丙二醛（MDA）水平,增加了超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）活性及谷胱甘肽（GSH）水平,400 mg·kg^-1的CWP干预效果最好（P<0.01）。结果提示,CWP干预能够以剂量依赖性方式降低大鼠肝氧化应激,增加抗氧化系统防御能力,从而缓解HS所致大鼠肝损伤。     

Ultrasonographic findings of the corpus luteum and the gravid uterus during heat stress in dairy cattle

The objectives of this study were to assess alterations in, echogenic appearance, size and blood flow in the corpus luteum, the placentomes and the blood flow in umbilical and uterine arteries that heat stress can cause in cooled pregnant dairy cows. Pregnant cows were allocated in two groups and the gravid uteri, along with the ipsilateral corpora lutea were examined during the winter (group W, n = 9) or the summer (group S, n = 10). The grey-scale ultrasound and colour flow imaging of the corpus luteum and placentome were performed. In addition, the umbilical and uterine artery diameters and haemodynamic parameters in the vessels were calculated. At the time of ultrasonographic examination, cortisol concentrations were higher, and progesterone levels tended to be lower in group S compared to group W. The grey-scale ultrasound evaluation of corpora lutea and placentomes was lower in group S compared to group W. The diameter of umbilical artery and the blood volume in the vessel were less in group S than in group W. We infer that heat stress affects foetal blood supply and possibly the structure of placentomes and corpora lutea, but it differently affects the blood flow characteristics in the umbilical and uterine arteries.     

两种运输车对驴运输应激的影响

本试验旨在研究改造运输车对缓解驴运输应激的效果。选取28头健康德州公驴,随机分为2组,从北京密云县运输至聊城市东阿县东阿黑毛驴研究所,路程约500 km,历时18 h。试验使用9.6 m长单层货车为运输车,对试验组(T)运输车进行改造,即加装顶层和双侧篷布、底部加装草帘和中部加装隔栏,对照组(C)不作处理。运输前后测定驴血液生化和激素指标,统计体重变化和发病驴数量。结果表明,与运输前相比,普通车组驴在落地当天检测到血清皮质醇(COR)、白蛋白(ALB)水平均显著升高(P<0.05),总蛋白(TP)、谷草转氨酶(AST)、热休克蛋白-90(HSP90)和肌酸激酶(CK)指标极显著升高(P<0.01),钙(Ca)浓度显著降低(P<0.05)。改造车组驴血液指标TP、AST和CK的变化范围低于普通车组。两组驴落地后血糖(GLU)水平均比运输前升高,但差异均不显著(P<0.05)。与运输前相比,改造车组驴落地后的体重减少低于普通车组;改造车组驴在落地后第10天平均体重接近运输前,而普通车组驴的平均体重在落地后第20天才基本恢复至运输前水平,即使用改造运输车辆可以尽早恢复体重。普通车组驴发病率为21.4%,改造车组为7.1%;两组均无死亡。综合上述结果,改造运输车可有效降低驴的运输应激,有利于提高动物运输福利,减少经济损失;本试验结果可为动物运输应激提供参考。     

Effects of dietary supplementation of nucleotides from late gestation to lactation on the performance and oxidative stress status of sows and their offspring

Increased metabolic burdens in breeding sows, which are induced by elevated systemic oxidative stress, could increase the need for nucleotides to repair lymphocyte DNA damage; however, de novo synthesis of nucleotides may be insufficient to cover this increased need. This study investigated the effects of dietary nucleotides on milk composition, oxidative stress status, and the reproductive and lactational performance of sows. Forty multiparous sows were assigned to 2 dietary treatments (Control group, and 1 g/kg Nucleotides group) based on a randomized complete block design using their BW at 85 d of gestation as a block. Sows from 2 groups were fed a restricted diet during gestation and ad libitum during lactation. The experiment lasted from 85 d of gestation to 21 d of lactation. The reproductive performance of sows and the growth performance of suckling piglets were measured. Oxidative stress parameters and milk components were also analysed. Data were analyzed using contrasts in the MIXED procedure of SAS. Sows in the Nucleotides group consumed more feed during the first week (P < 0.01) and from 1 to 21 d (P < 0.05) of lactation than those in Control group. Correspondingly, the litter weight gain of piglets showed a tendency to increase from cross-fostering to 9 d (P = 0.09) and from cross-fostering to 20 d (P = 0.10) in the Nucleotides group relative to the Control group. Additionally, the Nucleotides group was higher (P < 0.01) than the Control group in the concentrations of uridine 5''monophosphate, guanosine 5''monophosphate, inosine 5''monophosphate, adenosine 5''monophosphate and total nucleotides in milk. Furthermore, the Nucleotides group was higher (P < 0.01) than the Control group in the serum levels of total antioxidant capacity (P < 0.01) for sows at 109 d of gestation and glutathione peroxidase for weaning piglets, but lower at the levels of thiobarbituric acid-reactive substances (P < 0.05) in serum of weaning piglets. This study indicated that maternal dietary nucleotides could promote piglet growth, probably due to the higher lactational feed intake and higher concentration of nucleotides in the milk of sows, and lower oxidative stress for both sows and piglets.