鸡贫血病毒安徽分离株感染性克隆的构建及其感染特性

鸡贫血病毒（chicken anemia virus,CAV）是诱导雏鸡发生免疫抑制的重要病原之一。应用PCR方法从安徽某鸡场送检病鸡肝组织中检测并鉴定CAV,扩增病毒全基因组序列插入pcDNA3.1(+)载体,并引入含Kpn I （GGTACCCAG）酶切位点的9 bp外源性标签,获得顺次连接的双拷贝CAV基因组的重组质粒,通过脂质体介导转染鸡MDCC-MSB1淋巴细胞并拯救出CAV感染性克隆毒株。经动物试验,感染性克隆毒株在接种1日龄健康雏鸡后15 d,对胸腺等免疫器官指数影响较小,胸腺病变不明显,表明其感染能力减弱,为进一步分析CAV致病机制和筛选疫苗候选株奠定基础。     

Under drought conditions NaCl improves the nutritional status of the xerophyte Zygophyllum xanthoxylum but not of the glycophyte Arabidopsis thaliana

Zygophyllum xanthoxylum is a salt‐accumulating xerophytic species with excellent adaptability to adverse environments. Previous studies demonstrated that Z. xanthoxylum absorbs a great quantity of Na⁺ as an osmoregulatory substance under arid conditions. To investigate the nutritional status of Z. xanthoxylum in comparison with a typical glycophyte, Arabidopsis thaliana, seedlings were exposed to NaCl (50 mM for Z. xanthoxylum and 5 mM for A. thaliana), osmotic stress (–0.5 MPa), and osmotic stress combined with the NaCl treatment. Compared to the control, NaCl treatment or osmotic stress significantly increased Na⁺ concentration in leaves and roots of Z. xanthoxylum, but not of A. thaliana. Under osmotic stress, the addition of NaCl significantly increased Na⁺ concentration in leaves and roots of Z. xanthoxylum, resulting in improved biomass and tissue water content. However, such changes were not observed in A. thaliana. Compared to the control, K⁺ concentrations in leaves and roots remained unchanged in Z. xanthoxylum when exposed to osmotic stress, with or without additional 50 mM NaCl. In contrast, significant reductions in shoot K⁺ concentrations of A. thaliana were observed under osmotic stress alone or when combined with 5 mM NaCl. Moreover, NaCl alone or when combined with osmotic stress enhanced the accumulation of N, P, Fe, Si, Ca²⁺, and Mg²⁺ in Z. xanthoxylum, but did not cause such nutritional changes in A. thaliana. Compared to the glycophyte A. thaliana, Z. xanthoxylum could accumulate Na⁺ and maintain the stability of nutritional status at a relatively constant level to cope with drought stress.     

Chemical response of hardwood oligosaccharides as a statistical function of isolation protocol

Hardwoods contain a substantial amount of hemicellulose-type oligosaccharides, the chemical structures of which are typically categorized in the xylan saccharide class. The efficient and selective isolation of these hemicelluloses is regarded as one of the most critical obstacles to overcome for their eventual biomaterial and bioenergy utilization. Therefore, the objective of the current work was to perform a fundamental exploration of the function of extraction pH, temperature, and time on the final chemical properties of the extracted hemicelluloses. The extraction chemistries employed varied pH and showed that acidic conditions provided a higher extractive yield versus alkaline conditions. An alkaline environment gave higher yields than an acidic environment and also resulted in much higher lignin removal from wood, especially at high temperature. In general, control of the pH chemistry leads to a change in the carboxylic acid groups present in the extracts. When the extraction pH changed from acidic to alkaline, the total carboxylic acid group content in the hemicelluloses removed significantly increased due to more acetic acid group hydrolysis and increased lignin degradation.     

近自然经营对马尾松林不同发展阶段竞争关系的影响

以实施近自然经营措施8a后的幼龄林、中龄林、近熟林3个不同发展阶段的马尾松(Pinus massoni-ana Lamb.)林为研究对象,根据Hegyi竞争指数,探讨近自然经营对马尾松林竞争关系的影响.结果表明:调查林分中马尾松是数量最多的树种且占据绝对优势地位;实施近自然经营措施的林分中马尾松的优势度较对应的对照林分明显降低,主要伴生树种杉木(Cunninghamia lanceolata(Lamb.)Hook)、枫香(Liquidambar formosana Hance)、白栎(Quercus fabri Hance)、麻栎(Quercus acutissima Carruth)等优势度明显提升.随着径级的增大,马尾松林分整体竞争强度逐渐减小,经营林分更为明显.林木的竞争强度与胸径均符合幂函数关系,竞争强度随着个体的增大而减小;经营林分的趋势线比相应对照林分更平缓,更易达到稳定状态.不同发展阶段各树种的竞争强度均表现为经营林分马尾松的竞争强度与相应对照林分相比明显降低;伴生树种的竞争强度明显提升.综上,近自然经营能够有效改善马尾松林竞争关系,加速林分达到稳定状态.     

A method for intervertebral space distraction before stabilization combined with complete ventral slot for treatment of disc-associated wobbler syndrome in dogs

Objective— To evaluate the use of a modified K-wire spacer for maintaining intervertebral distraction after ventral decompression and during stabilization as a treatment for disc-associated wobbler syndrome in large breed dogs.
Study Design— A retrospective study.
Animals— Dogs (n=7) with disc-associated wobbler syndrome.
Methods— Medical records (2003–2006) of dogs treated by a modified surgical method were evaluated. Data retrieved were signalment, onset and duration of clinical signs, neurologic abnormalities, diagnostic methods, surgical procedure, immediate, and long-term (≥1 year) postoperative clinical and radiographic outcome.
Results— Mean duration of clinical signs was 4.8 months. Neurologic signs included ataxia (2), ambulatory tetraparesis (2), and non-ambulatory tetraparesis (3). Three dogs had disc protrusion in 2 sites, 2 dogs had the procedure in 1 location and stabilization of both affected sites. All dogs improved dramatically and remained for 1–3 years. One dog had recurrence of cervical discomfort 13 months later.
Conclusions— Despite the limited number of dogs, overall initial successful outcome with only 1 dog having mild recurrence 13 months later supports further use and evaluation of this technique.
Clinical Relevance— Distraction using a K-wire spacer after ventral decompression followed by stabilization should be considered in dogs with disc-associated wobbler syndrome to prevent collapse of the intervertebral space.     

猪德尔塔冠状病毒纳米PCR检测方法的建立

根据Gen Bank登录的猪德尔塔冠状病毒(PDCo V)毒株M基因设计特异性引物,建立了PDCo V纳米PCR检测方法并进行了临床样品检测。结果显示:该方法对标准品检测的最低浓度可达102 copies/μL,与其他几种常见猪病病毒无交叉反应;用该方法检测国内猪场62份腹泻粪便样品,相比常规PCR方法,该纳米PCR方法的检出率更高,而两种方法对268份进境活猪粪拭子样品检测均为阴性。结果表明,本研究所建立的纳米PCR检测方法适用于国内猪场的PDCo V检测和进境活猪的监控检测,可作为PDCo V实验室检测的有力技术手段。     

袋鼠疱疹病毒1型实时荧光PCR方法的建立

为实现袋鼠临床样本中疱疹病毒1型(Macropodid herpesvirus 1,MaHV-1)的出入境快速检测,基于MaHV-1的gB基因序列设计特异引物和TaqMan探针,建立了一种MaHV-1荧光PCR检测方法。试验结果显示,该方法只对MaHV-1 gB基因呈现特异性扩增,与禽传染性喉气管炎病毒、伪狂犬病毒和牛传染性鼻气管炎病毒不发生交叉反应,对阳性标准质粒对照(pCR-MaHV-1-gB)的最低检测限为8个拷贝数/反应。该方法的组内和组间试验的Ct值变异系数介于0.17%～0.96%之间,具有良好的重现性。试验结果表明,本研究建立的实时荧光PCR方法可用于袋鼠MaHV-1的病原学检测。     

接种茎段的部位与长度对无核枣试管苗生长的影响

将不同部位与不同长度的无核枣试管苗茎段接种于附加IBA 0．5mg／L和蔗糖15g／L的1／2 MS培养基上进行培养,上部茎段形成试管苗的新生茎长、总茎长、生根率等指标均极显著高于中、下部茎段,中、下部茎段之间上述指标无明显差异;长茎段（15～20mm）形成试管苗的新生茎长、总茎长、生根率及根长等指标均极显著高于短茎段（5～10mm）。上述结果表明,接种茎段的部位与长度对无核枣试管苗的生长有明显的影响,接种上部茎段和增加接种茎段的长度有利于促进试管苗的生长。     

航苜1号航天二次搭载SP 1代的农艺性状变异

本研究以航天二次搭载的航苜1号紫花苜蓿(Medicago sativa cv.Hangmu No.1)种子种植而成的当代(SP_1)试验材料(HY2)为研究对象,通过与未搭载的航苜1号种植材料(CK)的农艺性状进行比较,分析了航天二次搭载对航苜1号产生的诱变效应。初步结果表明,二次搭载的航苜1号,其平均株高、分枝数和多叶率显著高于对照(P0.05),表现出较强的生长势;多叶株较对照减少,7叶株显著增多(P0.05),出现了5株7叶率在60%以上的7叶株;5叶株较对照减少,5叶率在60%以上的5叶株较对照显著增加(P0.05),诱变效应明显,有益变异增多。该研究将为苜蓿品种的进一步改良提供有效的选育途径及优良的种质资源。     

豫北地区苹果树干皮缝中越冬的节肢动物种类调查初报

通过２ａ的调查结果表明,豫北地区苹果树干皮缝中越冬的节肢动物数量大,且种类繁多,其中包括农林作物和果树害虫及其天敌。统计分析表明,害虫占总数的８．３４％,天敌占总数的９１．６６％,蜘蛛类占天敌总数的４５．４５％,传统的冬季刮老树皮防治果树害虫的方法,能消灭部害虫,也能杀伤大量的害虫天敌、建议尽量不要刮树干老皮。