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61.
红树林放线菌生物多样性及其代谢产物的研究进展   总被引:1,自引:0,他引:1  
红树林放线菌具有极其丰富的多样性以及独特的代谢途径,其代谢产物结构新颖、生物活性显著,已成为抗菌、抗肿瘤、酶活性及酶的抑制剂等新药开发的重要来源。从红树林放线菌的生物多样性、代谢产物及其生物活性等方面对红树林放线菌的研究现状进行综述。  相似文献   
62.
Insulin-induced genes (INSIGs) are recently discovered genes that are involved in the metabolism of cholesterol and lipogenesis in animal tissues. In this study, two INSIG genes (INSIG1 and INSIG2) were isolated and characterized in 11 buffalo. The full-length coding sequence (CDS) of the buffalo INSIG1 consists of 831 bp which encodes a 276 amino acid protein with molecular mass 29.55 kD. And the INSIG2 CDS is 678 bp in length which encodes a 225 amino acid protein with molecular mass 24.87 kD. No polymorphisms were found in the CDSs of the buffalo INSIGs, but seven and two nucleotide differences were found in the CDSs between buffalo and other bovine species. Phylogenetic analyses based on the INSIG amino acid sequences showed that buffalo was grouped with other members in the Bovidae family. Four types of putative modification sites were detected in buffalo INSIG proteins. And two predicted microRNA target sites were found respectively in the CDSs of buffalo INSIG1 and INSIG2. The tissue expression analyses by quantitative PCR (qPCR) revealed that the buffalo INSIG1 was expressed in ten tissues tested. Among these tissues, the liver and mammary gland showed high expression levels. And the INSIG2 was only expressed in the brain, mammary glands, pituitary, abomasum, heart, and liver. Among these tissues, the mammary gland, brain, and pituitary demonstrated a high expression levels. These data provide the primary foundation for further insights into the buffalo INSIG genes.  相似文献   
63.
Since January 1 2013, group housing of sows has been compulsory within the European Union (EU) in all pig holdings with more than ten sows. Sows and gilts need to be kept in groups from 4 weeks after service to 1 week before the expected time of farrowing (Article 3(4) of Directive 2008/120/EC on the protection of pigs). The legislation regarding group housing was adopted already in 2001 and a long transitional period was allowed to give member states and producers enough time for adaptation. Even so, group housing of sows still seems to be uncommon in the EU, and is also uncommon in commercial pig farming systems in the rest of the world. In this review we share our experience of the Swedish 25 years of animal welfare legislation stipulating that sows must be loose-housed which de facto means group housed. The two most important concerns related to reproductive function among group-housed sows are the occurrence of lactational oestrus when sows are group-housed during lactation, and the stress that is associated with group housing during mating and gestation. Field and clinical observations in non-lactating, group-housed sows in Sweden suggest that by making basic facts known about the pig reproductive physiology related to mating, we might achieve application of efficient batch-wise breeding without pharmacological interventions. Group housing of lactating sows has some production disadvantages and somewhat lower productivity would likely have to be expected. Recordings of behavioural indicators in different housing systems suggest a lower welfare level in stalled animals compared with group-housed ones. However, there are no consistent effects on the reproductive performance associated with different housing systems. Experimental studies suggest that the most sensitive period, regarding disturbance of reproductive functions by external stressors, is the time around oestrus. We conclude that by keeping sows according to the pig welfare-friendly Directive 2008/120/EC, it is possible to combine group-housing of sows with good reproductive performance and productivity. However, substantially increased research and development is needed to optimize these systems.  相似文献   
64.
Control of canine leishmaniasis is an important objective for the benefit of dogs living in or visiting endemic areas and for public health because of the zoonotic nature of this disease. Resistance or susceptibility to developing canine leishmaniasis after exposure to Leishmania infantum is primarily determined by the ability of the immune system to develop an appropriate Th1-dominated specific response to the parasite. For this reason there is a need for effective canine vaccines that can decrease the number of dogs developing progressive infections. In this study, we followed the impact of the LiESP/QA-21 canine vaccine (composed of excreted-secreted proteins of L. infantum and the QA-21 saponin adjuvant), recently launched commercially in Europe, on selected humoral and cellular immune parameters following an infectious intravenous challenge with L. infantum promastigotes administered one year after the primary vaccine course. We also followed parasitological parameters to determine the parasitological status of the challenged dogs. In contrast to controls, vaccinated dogs retained significantly stronger cell-mediated immune responses against the parasite despite a virulent challenge and had significantly lower mean parasite burdens at the end of the study, associated with a lower probability of developing active infections. These results confirm that the immune responses generated by vaccination with LiESP/QA-21 are still effective against an intravenous challenge one year after the primary vaccine course.  相似文献   
65.
柑桔脚腐病病原菌的生物学特性   总被引:1,自引:0,他引:1  
  相似文献   
66.
地面灌溉是一种古老而又应用最广的灌水方法,世界上各国都十分重视改进地面灌水技术的研究。本文提出了二种新的改进地面灌水技术设施——麦棉套膜上灌和简易间歇灌研究结果,它们均具有节水增产、灌水速度快、灌水均匀和投资小的优点,并对此二种地面灌水方法的设施、控制运用和节水增产机理作了初步探讨。  相似文献   
67.
鱼粉因其独特的营养价值,在水产、高档猪饲料中的应用具有不可替代的作用。国产鱼粉看山东,山东鱼粉看荣成。荣成市是我国著名的鱼粉原料集散地和鱼粉加工企业聚集地,在山东省乃至全国鱼粉产业发展中占据重要位置。作为一种资源型产业,鱼粉的发展得益于海洋资源,但近年来,随着环保管控力度加大,特别是鳀鱼资源的短缺,荣成的鱼粉生产经营进入了困难时期。面对发展困境,鱼粉行业应以可持续发展理念为指引,以建设环境友好型、资源节约型、产业集约型为目标,加快产业结构调整,推动技术进步与创新,实现鱼粉行业高质量发展。  相似文献   
68.
Summary Genetic analysis of resistance to PVY in androgenetic doubled haploid lines, F1, F2 and backcross progenies of the Mexican pepper line, CM 334 (Capsicum annuum L.), was performed. Three reaction types were observed when seedlings were inoculated with several PVY strains of different pathotypes and with an American PeMV strain. Resistant genotypes never showed systemic symptoms although some individuals sporadically developed necrotic local lesions on inoculated cotyledons. Susceptible genotypes exhibited either a typical systemic mosaic or a systemic necrosis that caused the death of the inoculated seedlings. Segregation analyses indicated that resistance to pepper potyviruses in CM 334 is conferred by two genes. The first one, tentatively named Pr4, is dominant and confers the resistance to all now known pathotypes of PVY and to PeMV. The second one, tentatively named pr5, is recessive; it confers only the resistance to common strains of PVY. The systemic necrotic response is conferred by an independent dominant gene, tentatively named Pn1.  相似文献   
69.
Catabolism of L-ascorbate by enteric bacteria is well documented, but no study has formally proved that bacteria of the Lactobacillus genus ferment this compound. However, some genes analogous to those of yiaK-S operon and ula regulon, which encoded proteins leading to L-ascorbate degradation by Escherichia coli and Klebsiella pneumoniae , have been identified in the recently sequenced Lactobacillus rhamnosus GG genome. Investigations by HPLC and in vivo (13)C NMR using L-[1,6-(13)C]-ascorbate showed that L. rhamnosus GG, a common probiotic strain, has the ability to catabolize L-ascorbate under anaerobiosis. The main products of the ascorbate degradation have been identified as CO(2), acetate, and lactate. These results are in accordance with the metabolic pathway proposed for the fermentation of L-ascorbate by E. coli.  相似文献   
70.
This study was conducted in an attempt to see whether single-layer centrifugation (SLC) increases the susceptibility of stallion spermatozoa to lipid peroxidation (LPO), in different extenders after removing all seminal plasma (SP). The susceptibility of stallion spermatozoa to LPO was studied before and after SLC. Each ejaculate was split, and aliquots extended with one of the three different extenders: INRA 96, Kenney's, or Equipro, and stored for 24 hours at 5°C (i). From the extended samples, an aliquot was kept as a control and the other was subjected to SLC through Androcoll-E. The selected spermatozoa were re-suspended in the appropriate extenders, without (ii) or with (iii) addition of 50% (v/v) pooled homologous SP for 24 hours at 5°C. Using ferrous sulfate as pro-oxidant, the susceptibility for LPO was flow-cytometrically assessed using the probe Bodipy581/591-C11. Sperm motility, monitored with a Qualisperm motility analyzer, increased after SLC treatment (P < .001). No significant correlations were found between motility and induced LPO with ferrous sulfate. The SP and extenders, per se, did not have a significant protective effect against LPO, but the interaction between SP and Kenney increased the susceptibility to LPO. However, the selected spermatozoa through Androcoll-E and the subsequent dilution in INRA had a significant protective effect against LPO (P < .05), especially when the oxidative insults were higher (80 μM).  相似文献   
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