5种中药提取物及其组合对嗜水气单胞菌的体外抑制作用

试验旨在探讨大黄、诃子、五倍子、黄连、黄芩5种中药及其组合对嗜水气单胞菌的体外抑制作用。试验测定了5种中药的水提物和醇提物对3株嗜水气单胞菌的抑菌圈、最低抑菌浓度（MIC）、最低杀菌浓度（MBC）及对嗜水气单胞菌生长的影响，采用棋盘交叉法测定了5种中药联合抑菌作用。结果显示，大黄和黄芩醇提物的抑菌圈显著高于其水提物（P<0.05），诃子和黄连水提物的抑菌圈显著高于其醇提物（P<0.05），五倍子水提物和醇提物抑菌圈大小相近。五倍子抗菌作用最强，其水提物和醇提物MIC为7.81～15.63 g/L，大黄醇提物和诃子水提物抗菌作用次之，MIC均为15.63～31.25 g/L。选择抑菌作用更强的提取物两两组合，五倍子水提物与其他4种中药提取物组合、大黄醇提物与黄连水提物组合均为协同作用；黄连水提物与黄芩醇提物组合为相加作用；大黄醇提物与黄芩醇提物、诃子水提物与黄连水提物组合均为无关作用；诃子水提物与黄芩醇提物组合为拮抗作用。研究表明，5种中药对嗜水气单胞菌均具有抑制作用，五倍子作用最强，五倍子水提物与其他4种中药提取物两两组合、黄连水提物与黄芩醇提物组合均可增强抗菌活性。     

云南马龙县山地封育草地凋落物分解与氮释放的研究

以云南马龙县退化山地草地为研究对象,对封育2年草地的凋落物、土壤水分、凋落物含水率,以及氮素释放进行了研究.结果表明.围栏封育草地凋落物分解速率显著高于未封育草地凋落物分解速率(P<0.05),封育区凋落物增加.起到了一定的保温作用,即可以加速凋落物的分解.同时也减少冬季低温对山地草地的伤害;草地凋落物的干物质分解速率与土壤含水率、凋落物含水率呈显著正相关(r=0.949,P<0.05),封育增加了土壤的含水率,促进了凋落物的分解.总氮的含量与凋落物分解速率成正相关(r=0.995,P<0.05).氨素是调节草地凋落物分解速率的一个重要因素.     

20味中草药与抗生素联用对猪源链球菌体外抑菌作用的分析

为观察中草药与抗生素联用对猪源链球菌的体外抑菌效果,采用试管二倍稀释法测定20味中草药水提物、醇提物的最低抑菌浓度（ MIC）,用常量棋盘稀释法测定20味中草药水提物、醇提物与抗生素联用对猪源链球菌的部分抑菌浓度（ FIC）。结果显示,所选20味中草药的水提物、醇提物对猪源链球菌均具有一定的抑菌作用,瓜蒌醇提物等对猪源链球菌的体外抑菌作用较强;败酱草水提物等对猪源链球菌的体外抑菌作用较弱。瓜蒌醇提物、乌梅醇提物、乌梅水提物与环丙沙星联合用药的抑菌作用表现为相加作用,板蓝根醇提物等与环丙沙星联合用药的抑菌作用表现为无关作用。     

天山北坡改良草地凋落物混合分解特征研究

研究凋落物分解过程及其调控机制对于预测生态系统凋落物分解、揭示营养元素循环规律具有重要意义。本试验采用野外凋落物网袋分解法,设置了紫花苜蓿（Medicago sativa）和无芒雀麦（Bromus inermis）不同混合比例的叶凋落物处理,在分解1个月、3个月和12个月后取出测定凋落物剩余量及碳氮含量。试验结果表明：单独紫花苜蓿凋落物的分解和碳、氮释放量均高于无芒雀麦凋落物单独分解,混合凋落物剩余率介于两种单一凋落物分解剩余率之间;混合凋落物紫花苜蓿和无芒雀麦凋落物比例为1：3的组合表现为显著的协同效应,其他组合为加和效应;凋落物剩余率及碳氮元素的剩余率与其初始氮含量呈负相关关系,与初始碳氮比呈正相关关系。研究结果表明,在新疆山地草原生态系统,凋落物混合分解效应与其组合比例密切相关,在豆禾凋落物适宜比例下混合凋落物分解可产生协同效应。     

荧光光谱法在半抗原-载体蛋白偶联物鉴定中的应用

对苯甲酸-牛血清白蛋白偶联物和苯胺-牛血清白蛋白偶联物进行荧光光谱鉴定。结果显示,对苯甲酸-牛血清白蛋白偶联物和苯胺-牛血清白蛋白偶联物的荧光光谱与其半抗原和载体蛋白相比均发生变化,苯甲酸-牛血清白蛋白偶联物和苯胺-牛血清白蛋白偶联物合成成功。研究表明,荧光光谱法是一种鉴定半抗原-载体蛋白偶联物的可行的方法。     

晋北半干旱草地不同分解程度凋落物混合对分解特征的影响

半干旱草地凋落物层广泛存在着不同分解程度的植物残体,为探究其混合分解对草地养分循环的影响,本研究采用野外凋落物分解袋法,对晋北半干旱草地3种乡土植物本氏针茅、艾蒿和铁杆蒿不同分解程度凋落物进行单独[新鲜凋落物（LFresh）、半分解凋落物（LAged）]或混合分解[新鲜凋落物与半分解凋落物1:1混合凋落物（LMix）],研究不同分解程度凋落物混合对分解特征的影响。结果表明：不同分解程度凋落物混合物的干重剩余率随分解时间增加而降低。在分解335 d后,其交互作用强度最大,具体表现为：针茅混合凋落物和铁杆蒿混合凋落物的干重剩余率实测值分别比期望值低5.12%、4.68%,表现为协同效应,而艾蒿混合凋落物表现为加和效应。此外,针茅不同分解程度凋落物混合分解可以促进N释放,抑制纤维素分解;铁杆蒿不同分解程度凋落物混合分解可以促进C释放和木质素分解。研究表明,不同分解程度凋落物混合可以改变分解速率,促进养分释放,从而对草地生态系统的养分循环产生影响。     

马齿苋不同提取物对肠炎沙门菌的体外抑菌试验

采用牛津杯法和平板法观察马齿苋水提物、醇提物和水煮醇提物对肠炎沙门菌的抑制作用。结果表明,马齿苋水提物和醇提物浓度为1 g/m L时,肠炎沙门菌对其表现为极敏;对水煮醇提物表现为高敏。提取物浓度为0.5 g/m L时,肠炎沙门菌对水提物表现为极敏;对醇提物和水煮醇提物表现为高敏。浓度为0.25 g/m L时,肠炎沙门菌对马齿苋水提物和醇提物表现为高敏;对水煮醇提物表现为中敏。3种提取物对肠炎沙门菌的MIC和MBC分别为0.025、0.025 g/m L和0.050 g/m L     

半干旱黄土丘陵沟壑区封禁流域植被枯落物分布规律研究

通过对陕北半干旱黄土丘陵沟壑区封育流域内不同立地条件下枯落物现存量的测定与分析,研究了枯落物的影响因子及分布规律。对60个样地调查研究结果表明:枯落物现存量与坡度呈二次回归关系,枯落物现存量最小值出现在坡度25.5°的位置;阴坡枯落物现存量比阳坡高25.1%,沟坡枯落物现存量比梁坡高41.7%;地表生物量与枯落物现存量呈显著的正相关性(P0.05);土壤含水量与枯落物现存量呈正相关性;土壤含水量与地表生物量两者的共同作用对枯落物现存量影响明显。     

增温对川西北高寒草甸草场植物凋落物分解的影响

凋落物分解是陆地生态系统碳循环的重要环节,温度是凋落物分解的关键影响因子。为探究增温对川西北高寒草甸草场植物凋落物分解的影响,使用开顶式生长箱(OTCs)研究模拟增温对分解袋法处理的凋落物样品的影响,以阐明增温对川西北高寒草甸生态系统中优势物种凋落物:禾本科的披碱草、发草,杂草类的野茴香、鹅绒委陵菜、蒙古蒿、星状雪兔子、长毛凤毛菊等群落混合地上凋落物和群落地下根系凋落物分解的影响。结果表明:1)模拟增温并未显著改变混合地上凋落物的分解周期,但是显著提高了根系凋落物的分解效率,地上、地下凋落物的分解周期对温度变化的响应存在差异。2)尽管不同种类植物凋落物的养分含量与化学计量特征存在显著差异(P<0.05),但与自然分解条件相比,模拟增温条件下单种植物地上凋落物的分解效率并未发生明显改变,模拟增温对单种植物地上凋落物的分解释放过程影响不显著。综上所述,川西北高寒草甸生态系统地上凋落物的分解过程对模拟增温响应不显著,而模拟增温显著影响地下凋落物分解过程。     

瘤胃内容物安全性和适口性评价

为了研究瘤胃内容物饲喂生长育肥猪的安全性和适口性,试验选择屠宰后牛羊的瘤胃内容物,经晾晒对瘤胃内容物进行安全性和适口性试验。结果表明:瘤胃内容物重金属含量低,病原微生物少,饲喂猪是安全的;瘤胃内容物饲喂生长育肥猪适口性好,在日粮中添加15%瘤胃内容物猪只采食量较常规饲料略有提高,说明瘤胃内容物可作为一种新的饲料进行运用。     

Handmade cloning:recent advances,potential and pitfalls

Handmade cloning(HMC) is the most awaited,simple and micromanipulator-free version of somatic cell nuclear transfer(SCNT).The requirement of expensive micromanipulators and skilled expertise is eliminated in this technique,proving it as a major revolution in the field of embryology.During the past years,many modifications have been incorporated in this technique to boost its efficiency.This alternative approach to micromanipulator based traditional cloning(TC) works wonder in generating comparable or even higher birth rates in addition to declining costs drastically and enabling cryopreservation.This technique is not only applicable to intraspecies nuclear transfer but also to interspecies nuclear transfer(iSCNT) thus permitting conservation of endangered species.It also offers unique possibilities for automation of SCNT which aims at production of transgenic animals that can cure certain human diseases by producing therapeutics hence,providing a healthier future for the wellbeing of humans.The present review aims at highlighting certain aspects of HMC including recent advancements in procedure and factors involved in elevating its efficiency besides covering the potentials and pitfalls of this technique.     

Successful Nonsurgical Transfer of Bovine Elongating Conceptuses and Its Application to Sexing

The objectives of the present study were to establish a nonsurgical transfer method for elongating bovine conceptuses and to combine this method with biopsy and sexing. Bovine conceptuses were recovered from donor cows on days 13–14 of the estrus cycle. In experiment 1, day 13 conceptuses were transferred to recipient cows using a standard day 7 embryo transfer (ET) method. The pregnancy rate of day 13 conceptus transfer (CT) is comparable to that of day 7 ET. In experiment 2, day 14 conceptuses were transferred using modified methods (balloon catheters or ET guns with modified sheaths). Using the standard ET method, no pregnancies were obtained; however, when balloon catheters or ET guns with modified sheaths were used, the pregnancy rates after CT were 48.0% and 44.8%, respectively. In experiment 3, day 14 conceptuses were biopsied without a micromanipulator, sexed using the loop-mediated isothermal amplification method and transferred to recipient cows. The pregnancy rate of biopsied conceptuses was 46.2% and did not differ significantly from that of unbiopsied conceptuses. Moreover, all pregnant cows transferred conceptuses following biopsy and sexing delivered calves with the expected sexes. These results suggested that the nonsurgical bovine CT method was comparable to day 7 ET and that this technique enables biopsy and sexing without expensive equipment such as a micromanipulator or specialized skills.     

山羊早期胚胎切割技术的比较研究

为了探求在生产实践中可行、对胚胎损伤较小的切割技术以获得同卵双生后代,研究采用简易显微切割技术和玻璃针透明带内切割技术,分别对山羊桑葚期胚胎进行切割。结果表明,利用显微切割刀进行山羊早期胚胎切割不仅可获得较高的移植产羔率(显微刀简易切割有效率为97.6%,产羔率为55.0%;玻璃针简易切割有效率为96.7%,产羔率为58.3%;玻璃针带内切割有效率为94.4%,产羔率为37.5%),而且不需要精密的显微操作装置,便于在基层生产中推广应用。     

Puncture of the Equine Embryonic Capsule and Its Repair In Vivo and In Vitro

Vitrification of embryos >300 µm in diameter requires puncture of the glycoprotein capsule, although the size of the hole compatible with embryo survival is unknown. Forty-five day-7 or -8 embryos were punctured using a 30-µm glass biopsy pipette mounted on a micromanipulator (n = 20) or manually with either an acupuncture needle (∼100-µm diameter -hole; n = 10) or a microneedle with a <1 µm tip to produce a ∼30-µm diameter hole (n = 15) before transferring to recipient mares; further 12 embryos were punctured with either the acupuncture needle or microneedle before being cultured in vitro for 48 hrs (n = 3 per puncture group) or transferred to recipient mares and recovered 48 hrs later (n = 3 per puncture group). No pregnancies resulted from the 10 embryos punctured with the acupuncture needle, whereas 15 of 20 (75%) and 10 of 15 (67%) punctured on the micromanipulator or manually with the microneedle resulted pregnancies. Neither acupunctured nor microneedle-punctured embryos repaired their capsules in vitro. The acupunctured embryos also failed to repair their capsule after 48 hrs in vivo and subsequent uterine flushing yielded numerous capsular vesicles. The microneedle-punctured embryos did repair their capsule in vivo. Puncture with the microneedle opens the way for development of a manual method to vitrify equine embryos.     

不同分割液对奶牛不同阶段胚胎分割效果的影响

本试验探讨了3种不同分割液对奶牛桑葚胚和囊胚分割效果的影响。借助显微操作仪，将发育至第6～8天的体内常规生产的桑葚胚和囊胚进行分割，体外培养半胚，观察其发育情况，选择形态恢复好的半胚与一个囊胚滋养层细胞囊泡（trophoblastic vesicles，TRV）共移植。结果显示，在PBS+0.2 mol/L蔗糖与PBS+5%PVP中分割桑葚胚，其分割成功率显著高于PBS（P<0.05），分别为89.13%、86.73%和69.67%，而半胚的囊胚发育率及移植妊娠率三者均无显著差异（P>0.05）；在PBS+0.2 mol/L蔗糖与PBS+5%PVP中分割囊胚， 其分割成功率显著高于PBS（P<0.05），分别为94.52%、92.52%和70.52%，而半胚培养的囊胚发育率及移植妊娠率三者均无显著差异（P>0.05）；说明在PBS中分别添加0.2 mol/L的蔗糖和5%的PVP有利于提高奶牛桑葚胚和囊胚的分割成功率。     

A simple and efficient method for isolation of a single Eimeria oocyst from poultry litter using a micromanipulator

The chicken, which is the host for seven species of Eimeria, typically is infected simultaneously by multiple Eimeria species and the oocysts of coccidia are excreted in the feces. A prerequisite for investigation of individual Eimeria species is to isolate a single oocyst from fecal samples. A novel method for isolating a single Eimeria oocyst from poultry litter using a micromanipulator was developed. This simple method is fast and reliable, and provides direct isolation of a single sporulated oocyst from fecal samples harboring multiple Eimeria species or samples contaminated by other species of parasite.     

Production of sheep-goat chimeras by inner cell mass transplantation

Embryos were surgically flushed from goats and sheep on d 6 and 7, respectively, following the first day of estrus (d 0). After enzymatic removal of the zonae pellucidae, inner cell masses were isolated from caprine blastocysts by immunosurgery. The intact inner cell masses were injected into ovine blastocysts with the aid of a micromanipulator. Twenty-two manipulated blastocysts were surgically transferred into 12 ovine recipients. Nine ewes gave birth to a total of 13 young (59% embryo survival). Ten were classified by serum electrophoretic assays or karyotypes as lambs, one as a kid, and two as interspecific chimeras.     

猪卵母细胞和早期胚胎透明带杨氏模量变化

在39℃环境下,利用微管吸吮的方法,在倒置显微镜下,通过显微操作装置用显微玻璃管吸吮猪卵母细胞和早期胚胎来测定其透明带的杨氏模量。结果显示,从猪卵巢抽取的未经体外成熟培养的卵母细胞(GV期)一直到早期囊胚(未扩张囊胚)阶段,其透明带杨氏模量一直都无显著变化,均集中在20 kPa左右,但当发育到扩张囊胚期其透明带杨氏模量明显变大(P0.05),且扩张囊胚中化学激活的明显大于体外受精的(P0.05)。结果提示,在猪卵母细胞和早期胚胎发育进程中,其透明带的刚性在扩张囊胚期最大,这为通过某些理化方法来帮助扩张囊胚期的胚胎孵化,从而提高囊胚的孵化率并最终提高妊娠率提供了力学方面的理论参考。     

Factors affecting premature chromosome condensation of cumulus cell nuclei injected into rat oocytes

To date, production of cloned rats by somatic cell nuclear transfer (NT) has not yet been successful. Inducing premature chromosome condensation (PCC) of injected cell nuclei in recipient cytoplasm is considered essential for successful mouse cloning by the Honolulu method. In the present study, some factors affecting PCC of rat cumulus cell nuclei injected into rat oocytes were examined. Wistar female rats (young: 4 to 5-week-old, mature: > or =10-week-old) were superovulated by injections of eCG and hCG, and oocytes recovered 14 or 17 h after hCG injection were received with cumulus cell nuclei using piezo-driven micromanipulator. When the oocytes were recovered 14 h post-hCG injection from young rats and the nuclear injection into oocytes was completed within 45 min, PCC was observed in 44-49% of NT oocytes. In the case of oocytes from mature rats, PCC occurred in 11-19% of the NT oocytes. Oocytes recovered 17 h post-hCG injection did not support PCC of the injected nuclei (0-7%) regardless of the donor age. Treatment of oocytes with a neutral cysteine protease inhibitor, N-acetylleucylleucylnorleucinal, slightly increased the incidence of PCC (48 vs 37%). Comparison of rat strains for oocyte donors indicated that proportions of NT oocytes undergoing PCC in Wistar and LEW oocytes (41-46%) were higher than those in Donryu and F344 oocytes (17-25%). Thus, ability of rat oocytes to promote PCC of the injected nuclei is dependent on the characteristics of oocytes, such as age or strain of donor rats, and timing of oocyte recovery.