江淮地区蜂群室外无包装扣王越冬技术研究     

王启发  李位三  李雪梅  曹小汉 《蜜蜂杂志》2003,(11):3-4

在室外无包装越冬期间 ,扣王与放王的蜂群进行对比实验 ,在饲料消耗、群势变化、蜂王越冬成败等方面均出现明显的差异。 3年的实验结果表明 :蜂群室外无包装 ,整个越冬期扣王 ,能较好地节约饲料、保持群势。  相似文献   

建筑物增层工程勘察方法探讨     

曹早平 《林业勘察设计》2003,(1):100-103

为提高建筑物的使用效能、节省土地空间、合理利用有限资金，业主会考虑在原有建筑物基础上进行增层利用，章就建筑物增层工程勘察方法进行探讨。  相似文献   

浅谈中国家畜多样性的保护   总被引：2，自引：0，他引：2  

曹果清  周忠孝 《家畜生态》2001,(2)

本文概述了我国家畜多样性的现状 ,指出家畜多样性保护是客观实际的需要 ,是畜牧业持续发展的需要 ,也是解决生存问题的需要 ,并进一步提出了家畜多样性的保护目标和利用策略  相似文献   

西藏山茉莉的生物学特性及人工栽培技术     

曹基武  唐文东  陈湘会  徐运海 《林业科技》2001,26(2):61-62

概述了珍稀树种－西藏山茉莉的分布概况、生物学物 及适生环境，并对其繁殖方法和人工栽培技术进行了试验研究，为开发与利用这一珍贵树种资源提供科学依据。  相似文献   

Inhibition of NF-κB activation by pvrrolidine dithiocarbamate increases sensitivity of HL-60 cells to cytotoxic drugs     

CAO Wen-jing  ZHANG Yao-zhen  ZHANG Dong-hua  LI Deng-ju  TANG Jin-zhi 《园艺学报》2005,21(9):1787-1790

AIM: To explore whether inhibition of NF-κB by antioxidant pvrrolidine dithiocarbamate (PDTC) sensitizes leukemia cells to cytotoxic drugs and its mechanism. METHODS: The indirect immunofluorescence method and electrophoretic mobility shift assay (EMSA) were used to measure the activation of NF-κB. The apoptotic cells were evaluated by flow cytometry (FCM) and the in vitro growth inhibitory effect was performed using a MTT assay. RESULTS: EMSA showed that NF-κB was activated by daunorubicin (DNR), VP-16 and then was inhibited by PDTC in a dose-dependent manner. NF-κB activation was further verified because of subunit RelA of NF-κB locating in the nuclei. FCM analysis showed that apoptotic index of HL-60 cells was up to (8.97±0.81)%, (16.01±1.06)%, (22.96±1.33)% from (5.34±0.62)%, (10.16±0.42)%, (17.32±1.15)% after exposure of HL-60 cells to 2.5-10 mg/L VP-16 combined with PDTC. VP-16 added with PDTC produced greater growth inhibitory effect to HL-60 cells than did VP-16 or DNR only (P<0.01). CONCLUSION: Reactive oxygen intermediates play an important role in inducible NF-κB activation. The inhibition of NF-κB by antioxidant PDTC sensitizes HL-60 cells to cytotoxic drugs.  相似文献   

高纯氮气对储粮害虫致死效果的研究   总被引：6，自引：2，他引：4  

张建军  曲贵强  李燕羽  曹阳 《粮食储藏》2007,36(5):11-14

本研究在30±1 ℃,相对湿度75%±5%的高纯氮气环境中对几种主要储粮害虫进行生物测定并检测结果.玉米象、米象、谷蠹、赤拟谷盗(中山品系)、杂拟谷盗、赤拟谷盗(益阳品系)、嗜卷书虱和锯谷盗的LT50值由大到小排列顺序为34.0 h、32.5 h、32.5 h、13.9 h、13.4 h、12.5 h、5.4 h和5.1 h.不同试虫对高纯氮气环境忍耐能力差异显著.  相似文献   

南瓜疏松愈伤组织诱导的研究     

邹克琴  张拥军  楼纪东  丰金平  曹恬 《北方园艺》2007,(12):201-203

获得生长迅速,疏松的愈伤组织是进行植物细胞悬浮培养的前提.研究以"粟冠"南瓜子叶做外植体,在添加不同浓度的BA和NAA的MS固体培养基上诱导南瓜愈伤组织,比较南瓜愈伤组织的诱导率和长势,其中当外植体在MS 1.0 mg/L6-BA 0.1 mg/L NAA的培养基上培养时,愈伤组织诱导率和长势最好.  相似文献   

Estimation of Genetic Parameters and Analysis of Season Effects and Age Effects for Semen Traits in Landrace Boars     

SHANG Xiuguo  YU Weiwei  ZHAO Yunxiang  ZHU Xiaoping  CAO Tingting  GAO Guangxiong 《畜牧兽医学报》1956,51(10):2425-2432

The purpose of this study was to estimate the genetic parameters of semen traits of Landrace boars in South China and to analyze the influence of the age and season of semen collection on semen traits, so as to provide theoretical basis for formulating reasonable boar breeding program. The Asreml-R was used to analyze the 107 221 semen data of 1 605 Landrace boars from 2 AI stations in Southern China, the single-trait repeatability animal model was used to estimate the variance components, heritability and repeatability of each semen traits, two-trait repeatability animal model was used to estimate genetic correlation and phenotypic correlation of semen volume, semen density, sperm motility and percentage of abnormal sperm. The general linear model of R language program was used to analyze the influence of age and season of semen collection on semen traits. The results showed that the semen volume and percentage of abnormal sperm had medium heritability (0.23 and 0.38), and the variation coefficient of percentage of abnormal sperm was 85.42%, while the other traits had low heritability (0.07-0.19). Semen volume-semen density and sperm motility-percentage of abnormal sperm had extremely significantly negative genetic correlation(-0.77 and -0.90, respectively). Semen density-sperm motility showed extremely significantly positive genetic correlation (0.50). The influence of the age of semen collection on semen traits was significant(P<0.05). After boars reached sexual maturity, semen volume showed a significant increase, semen density and percentage of abnormal sperm showed a general decrease, and total sperm number and functional sperm number were significantly higher in the 13-18-month of age group than those in the other groups (P<0.05). The semen density was the highest in spring, and the total sperm number and functional sperm number were significantly higher in autumn and winter than those in spring and summer (P<0.05). In conclusion, the semen volume and percentage of abnormal sperm of Landrace boars can be selected as candidate traits. In the boar production management, boar whose semen production after 36 months of age decline, will be considered to update. Boar semen quality was significantly higher in autumn and winter than those in spring and summer. It is suggested that cooling work should be done in advance in Southern China in summer.  相似文献   

大力推进湖南棉种产业化经营     

曹丽之  吴若云 《湖南农业科学》2001,(1):48-50

湖南省棉种产业化的建设，以推广杂交棉为依托，以市场、基地、科技为基础，以质量、效益、发展为中心，以股份制企业为龙头，依靠行政和经济手段，有机地把棉花新品种选育、科技开发、良种繁育、加工销售和推广应用相结合，并积极创造各项条件，实施名牌战略，坚持“五统一”管理原则，培育出较为成熟的商品化棉种消费市场，从而使我省棉种产业逐步走上管理法制化、生产专业化、加工机械化、质量标准化、经营集团化、育繁推一体化的轨道。  相似文献   

A method of inducing mouse embryonic stem cells cultured in vitro to differentiate into cardiomyocytes     

ZENG Qiu-tang  CAO Lin-sheng  ZHU Wu-qiang 《园艺学报》2001,17(7):628-631

AIM:To evaluate the method of inducing mouse embryonic stem (ES) cells in vitro to differentiate into cardiomyocytes without using any chemical reagents.METHODS:BRL conditioned medium was used to promote the growth of ES cells and maintain them in an undifferentiated state before the experiment of differentiation. Then a three-step method including ES cell culture in hanging drops and in suspending was used to induce the differentiation of ES cells. RESULTS:Rhythmically contracting cells were observed among differentiated cells, which were proved to be cardiomyocytes with electron microscope and immunocytochemistry. CONCLUSION:A simple and economical method was established to induce mouse ES cells cultured in vitro to differentiate into cardiomyocytes without using any chemical reagents.  相似文献