318 research outputs found

    人力资源发展的相关理论及其历史沿革

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    随着时代的演进和科技的发展,个人必须不断充实自己,才能应付工作与生活的变迁,终身学习的观念逐渐形成;企业面临产业型态的改变、科技水平的提升与国际竞争的激化,产生了危机感,企业再造与人力资源发展等课题因而受到高度的重视

    Establishment of MDCK cell lines which stably express visualable human neonatal Fc receptor

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    [目的]建立稳定表达融合EGFP的人新生儿Fc受体(h FcRn)的MDCK细胞株。[方法]构建重组慢病毒质粒p EGFP-h FcRn,采用四质粒包装系统共转染HEK 293T细胞生产重组慢病毒,感染MDCK细胞后对EGFP阳性细胞进行流式单细胞分选;通过Western Blot及EGFP-β2m荧光共定位验证h FcRn的完整性,并用流式细胞仪检测h FcRn与人Ig G的结合活性。[结果]测序结果表明成功构建p EGFP-FcRn慢病毒表达载体;感染后EGFP阳性MDCK细胞比例约为26.5%,流式单细胞分选后得到纯阳性细胞;荧光共定位及Western Blot均检测到h FcRn的完整表达;流式分析表明细胞株上的h FcRn与Ig G存在p H依赖性结合。[结论]成功获得稳定表达具有生物活性的可视化h FcRn的MDCK细胞株。[ Objective] To establish MDCK cell line stably expressing EGFP- human neonatal Fc receptor(hFcRn) fusion protein. [ Methods ] The lentiviral expression vector for EGFP - hFcRn fusion protein was constructed. Generating by co - transfection of four -plasmids into HEK 293T cells ,the lentivirus particles were used to infect MDCK cell line. EGFP positive single cell was obtained by FACS, and then FcRn expression was identified by fluorescence co -location with EGFP - β2m and confirmed by Western Blot. Flow cytometry was used to detect binding activity of hFcRn and human IgG. [ Results ] DNA se- quencing demonstrated that the lentivirus vector pEGFP - FcRn was constructed successfully. The percentage of EGFP - posi- tive ceils was about 26.5% after infection. Expression of the complete protein was detected through fluorescence co - location and Western Blot, respectively. Flow cytometry analysis showed that the cell lines could pH - dependently capture human IgG. [ Conclusion] MDCK cell line stably expressing functional visualable hFcRn was established.基金项目:国家自然科学基金项目(“结构生物学指导的HBV治疗性抗体人源化及其关键技术研究”,No.31600748;“抗呼吸道合胞病毒高中和活性抗体的保护机制研究”,No.81401668;“基于广谱中和单抗的通用型流感疫苗设计及其结构基础研究”,No.31670934

    Kinetics of Vesicle Formation and Breakdown

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    利用停流装置研究了十二烷基硫酸钠(SDS)和十二烷基三甲基溴化铵(DTAB)复配形成囊泡的过程和囊泡破坏过程的动力学性质,并结合动态光散射技术和电子透射显微镜探索囊泡形成和囊泡破坏过程的机理.动态光散射和电子透射显微镜的研究结果表明囊泡的形成过程主要包括四个阶段:混合胶团→柔性的长棒状聚集体→"非平衡囊泡"→平衡囊泡,而与其对应的粒度分散度则呈现"单分散性→多分散性"的周期性变化规律.此外,动力学结果表明囊泡形成过程很长,但其活化能不大,这意味着囊泡形成过程的控制步骤可能不是活化能控制.而相对于囊泡的形成,囊泡的破坏过程是十分迅速的.A combination of stopped-flow,transmission electron microscopy and dynamic light-scattering techniques has been used to study the kinetics of vesicle formation and breakdown as well as the mechanism of vesicle formation and breakdown in DTAB/SDS aqueous solutions.The results show that the process of vesicle formation can be modeled as a sequence of distinct processes:mixed micelles→flexible stick-shaped aggregates→non-equilibrium vesicles→equilibrium vesicle system,and the evolution of particle dispersion degree appears to be a periodical change of "monodispersity→polydispersity".In addition,the kinetic analysis shows that the process of vesicle formation lasts for a long time.However,the activation energy of vesicle formation is not too high,which implies that the control procedure of the process is independent of activation energy.In contrast to the process of vesicle formation,vesicle breakup to mixed micelles appears to be a rapid process.厦门大学科技创新重点项目(No.XMKJCX20052001)资助项目

    Studied the difference of genetic feature between tissue cultured and cultivated paddy rice of Jia He Zao Zan via microsatellite(SSR) markers

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    株高是水稻重要的农艺形状之一,植株过高将导致倒伏和减产,目前,很多新的技术究被用来鉴定,图位克隆与水稻株高相关的基因及机理的研究,本实验选择优质早籼稻佳禾早占种植苗和经过组培获得的矮化突变水稻为材料,为研究比较它们间的遗传物质上差异,根据康耐尔大学的资料设计了311对SSR引物对佳禾早占种植材料和组培材料进行分析,对两种材料进行PCR多态性扩增,结果发现两者间存在多态性的引物有88对,多态性比例达到30.3%。在矮杆材料中不但验证了已报道的11个与调控株高性状基因相连锁的标记连锁群,同时在第3号染色体和第9号染色体上还获得了两个以前基本未有报道的标记集中分布区域。结果说明,该培养基培育出的佳禾早占水稻后代所表现出的矮杆性状与亲本在遗传物质上确有明显差别。该结果有助于挖掘和定位新的矮杆基因,并有利于今后在水稻育种中进行水稻株高性状的控制,同时也为开展矮化性状机理的研究提供有利的实验材料。Plant height is one of the important agronomic traits of rice.Overhigh plant easily led to lodge and reduce output.Recently,great advances have been made in the identification,mapping,cloning and action mechanism of plant height genes in rice.This present paper selected the tissue cultured and cultivated paddy rice of Jia He Zao Zan(J.H.Z.Z) as experimental object,which were significant different on the height,the tissue cultured plant was only less than half height of the cultivated plant.In order to compare their differences of genetic and determine whether there are relationship between the dwarf gene and the dwarf character of tissue cultured plant,Polymorphism analysis was conducted between them by 311 pairs of rice SSR primers,designed by Cornell University,the result indicated that 88 pairs of primers had polymorphism between two kinds of materials,the ration in total primers was about 30.3%,the experimental result not only verified 11 multiple groups which regulate the height gene,but also obtained two group regions which control the dwarf character on chromosome 3 and chromosome 9,which have not been reported previously,these results will help to explore and determine the situation of new dwarf gene,and will be of benefit to act genetic manipulation of plant height of in rice breeding.These results also provided the evidence for studying the mechanism of dwarf.国家863项目(2002AA211091),(20001AA11091);; 厦门大学细胞生物学和肿瘤细胞工程教育部重点实验室开放基金资助(NO:2005108)资

    Assessing ecological risks of different valence states of Cr to marine organisms by species sensitivity distributions

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    应用生态风险评价中的物种敏感性分布(SSd)方法构建了3种不同形态(Cr、Cr3+、Cr6+)的重金属Cr对海洋生物的SSd曲线。在此基础上计算了3种形态的Cr对不同海洋生物的5%危害浓度(HC5)和其不同暴露浓度对海洋生物的潜在影响比例(PAf),比较了海洋脊椎动物和无脊椎动物对不同形态的重金属Cr的敏感性以及不同形态的Cr的急性生态风险,并且评价了两个港湾海水水体中常见形态的重金属Cr的联合生态风险。结果表明,3种形态的重金属Cr的HC5的大小顺序为Cr3+>Cr6+>Cr。浓度小于10μg/l时,Cr、Cr3+、Cr6+三者生态风险差异不大,且都处于相对较低的水平。在10μg/l的暴露浓度下,三者所影响的海洋生物比例均未超过5%。随着浓度升高,生态风险也相应增大。当浓度达到1 000μg/l时,分别有23.43%,13.73%和17.27%的物种受到Cr、Cr3+、Cr6+的损害,此时三者的生态风险差异也比低浓度时有所增大。当不同形态的重金属Cr浓度在不同的范围时,不同生物的敏感性大小顺序会发生变化。三种形态的重金属对无脊椎动物的生态风险均比脊椎动物(本文即指鱼类)大。两个海湾水体重金属生态风险的大小顺序为宁德海域(0.66%)>福清海域(0.63%)。Species sensitivity distributions(SSD) method was used to assess the ecological risk of three valence states of Cr(Cr,Cr3+,Cr6+) to marine organisms.The acute toxicity data(LC50 or EC50) were collected from ECOTOX database and SSD curves were fitted based on BurrIII and ReWeibull function.The acute ecological risks of different valence states of Cr and the sensitivity of different marine species(vertebrate and invertebrate) to these different valence states of Cr were compared by the hazardous concentrations for 5% of the species(HC5) and the potential affected fractions(PAF).Then the HC5 values of these different valence states of Cr were in the order:Cr3+> Cr6+> Cr.When exposure concentration was lower than 10 μg/L,no significant differences among the ecological risks of Cr,Cr3+ and Cr6+ was observed.Also,none of these four observations exceeded the threshold of 5%(PAF) at the exposure level of 10 μg/L.The ecological risks of the heavy metals increased as the exposure concentration increased.When came up to 1 000 μg/L,23.43%,13.73% and 17.27% of marine species would be affected by Cr,Cr3+ and Cr6+,respectively.The order of sensitivity to marine species varied with different concentration of heavy metals.The ecological risk of all these three valence states of Cr to invertebrate was higher than to fishes.The case studies showed that the ecological risk of different valence states of Cr in the Seas of Ningde was higher than that in the Seas of Fuqing.国家自然科学基金资助项目(31101902); 国家海洋局青年海洋科学基金资助项目(2011143); 海洋公益性行业科研专项经费资助(201105015); 福建省自然科学基金资助项目(2012J05074); 国家海洋局第三海洋研究所基本科研业务费专项资金资助项目(海三科2011006

    Malignant transformation arising from mature cystic teratoma of the ovary presenting as ovarian torsion: a case report and literature review

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    Objective: Ovarian torsion is an acute gynecological condition. Torsion is more likely to occur with benign rather than malignant tumors. Mature cystic teratoma of the ovary (MCTO) is frequent in women of reproductive age; however, the incidence of malignant transformation is approximately 2%. We report a case of malignant transformation of MCTO presenting as ovarian tumor torsion. Case report: A 51-year-old premenopausal woman was diagnosed with mature cystic teratoma in the left ovary 7 years ago. The patient visited our hospital because she had been experiencing of pain in left lower abdomen for the past two days. She was diagnosed with ovarian tumor torsion and underwent emergency surgery. The left ovarian tumor was twisted, and left salpingo-oophorectomy was performed. Histopathological examination revealed squamous cell carcinoma arising from the MCTO. We carefully followed the patients without performing staging laparotomy. On postoperative day 112, multiple lymph node metastases in the pelvic and para-aortic areas were found by positron-emission tomography and computed tomography. After referral to a university hospital, total hysterectomy, right salpingo-oophorectomy, partial omentectomy, and pelvic and paraaortic lymphadenectomy were performed. Metastases of squamous cell carcinoma were confirmed in the pelvic and para-aortic lymph nodes. Six courses of adjuvant chemotherapy with paclitaxel and carboplatin were given following radical surgery to prevent the recurrence of malignant transformation of MCTO. No recurrence of the disease has been observed during 2 years of follow-up. Conclusio: When physicians diagnose large ovarian tumor torsion cases, preoperative examinations should be performed, with the possibility of malignancy in mind

    Successful management of preoperatively diagnosed torsion of a subserosal uterine fibroid by pneumoperitoneum laparoscopic single-port surgery

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    Objective: Preoperative diagnosis and successful management of acute torsion of a subserosal fibroid by using appropriate imaging modalities and single-port laparoscopic surgery. Case report: A 44-year-old nulliparous woman presented with lower abdominal pain. Computed tomography and magnetic resonance imaging with contrast enhancement revealed a tumor in the pouch of Douglas with a low contrast at the center and thin-rim enhancement. Torsion of a uterine subserosal fibroid was diagnosed preoperatively. Laparoscopic single-port surgery by pneumoperitoneum was performed. Torsion of the pedicle attached to the uterine wall was excised by bipolar coagulation and cut with scissors. The extirpated fibroid was extracted from the umbilical wound. The pneumoperitoneum single-port laparoscopic surgery was completed as a gynecologic emergency operation. Conclusion: Torsional uterine fibroids are difficult to diagnose preoperatively as symptoms are nonspecific and need emergent surgical management as an acute abdomen. Preoperative diagnosis using appropriate imaging modalities is important to perform single-port laparoscopic surgery
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