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141.
Using the rigid and hydrophobic polystyrene (PS) chain as backbone, onto which flexible and hydrophilic stearyl-poly(ethylene oxide) (SPEO) chains are grafted, a new kind of amphiphilic, microphase-separated graft copolymer was synthesized using the macromonomer technique. Stearyl-poly(ethylene oxide) macromonomers with acryloyl end-group (SPEO-A) were prepared through an end-group exchange reaction of α-stearyl-ω-hydroxypoly(ethylene oxide) (SPEO-OH) and acryloyl chloride in the presence of triethylamine. The radical copolymerization of styrene with SPEO-A was carried out under various experimental conditions. Following a careful examination of their purity, the structure of the prepared copolymers was characterized by means of IR, 1H NMR and GPC analyses. A new feasible method using first derivative UV spectrometry was developed for quantitative determination of the bulk composition of the graft copolymers. Copolymers with a wide range of bulk composition and satisfactory grafting degree were obtained.  相似文献   
142.
领导干部心理健康量表的初步编制   总被引:1,自引:0,他引:1  
目的编制一套适用于领导干部群体的心理健康量表。方法通过文献研究、个案分析、问卷调查等,确立测验结构并编制成预测量表,通过对127位被试施测结果进行条目分析等形成正式量表,并进行因子分析等考察量表的信度和效度。结果编制成一个含3个量表:心理症状量表、自我概念量表、外界适应量表,共计93个项目的测评系统。项目与其所在量表的题总相关系数在0.445~0.855之间(P<0.001),各条目决断值(CR值)均具有显著性;对自我概念量表和外界适应量表探索性因素分析分别提取4个和3个公因子,累计解释总变异量分别为54.842%,48.365%,因子载荷在0.427~0.814和0.434~0.796之间;各量表的Cronbach'sα系数分别为0.775,0.860,0.952。结论初步研究显示量表的信效度均达到心理学测量标准,具有较好的信效度。  相似文献   
143.
We report on the antileukemia effect of interleukin 2 (IL2) on different immune cells from 22 patients with chronic myeloid leukemia (CML). Bone marrow cells from these patients were first cultured in modified long-term bone marrow culture medium for several days, then separately cultured with lymphokine activated killer cells (LAK), cytokine-induced killer cells (CIK), and dendritic cell cocultured CIK (DC-CIK) for another 1-2 days. They were then detected for presence of the Philadelphia chromosome (Ph) by cytogenetic analysis and fluorescence in situ hybridization (FISH). The percentage of Ph-chromosome-positive cells in the bone marrow mononuclear cells after culturing with CIK and DC-CIK was significantly lower than that after culturing with IL2 or LAK. Our results demonstrate that cytogenetics and FISH are useful techniques for the evaluation of the anti-CML effect of immune cells and that CIK or DC-CIK can be appropriate candidates for adoptive immune cell therapy in vivo or for leukemia cell purging ex vivo.  相似文献   
144.
145.
Wei H  Qin ZH  Senatorov VV  Wei W  Wang Y  Qian Y  Chuang DM 《Neuroscience》2001,106(3):603-612
Huntington's disease is a progressive, inherited neurodegenerative disorder characterized by the loss of subsets of neurons primarily in the striatum. In this study, we assessed the neuroprotective effect of lithium against striatal lesion formation in a rat model of Huntington's disease in which quinolinic acid was unilaterally infused into the striatum. For this purpose, we used a dopamine receptor autoradiography and glutamic acid decarboxylase mRNA in situ hybridization analysis, methods previously shown to be adequate for quantitative analysis of the excitotoxin-induced striatal lesion size.Here we demonstrated that subcutaneous injections of LiCl for 16 days prior to quinolinic acid infusion considerably reduced the size of quinolinic acid-induced striatal lesion. Furthermore, these lithium pre-treatments also decreased the number of striatal neurons labeled with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. Immunohistochemistry and western blotting demonstrated that lithium-elicited neuroprotection was associated with an increase in Bcl-2 protein levels.Our results raise the possibility that lithium may be considered as a neuroprotective agent in treatment of neurodegenerative diseases such as Huntington's disease.  相似文献   
146.
我们对采用PCR和聚丙烯酰胺凝胶电泳鉴别出的37例DNA完全来自父方的遗传学完全性葡萄胎(g-CHM)进行基因组中CTTtriplex系统各基因座位(CSF1PO、TPOX和TH01)等位基因分布的分析,并初步研究了这些等位基因分布与临床预后的关系。结果显示,在37例g-CHM中,CSF1PO座位中3个等位基因(11,12和14)和TPOX座位中的1个等位基因(11)的出现率与它们在北京地区人群中的基因频率差异显著;g-CHM中CSF1PO、TPOX和TH01基因座位杂合度显著低于北京地区人群的杂合度(P值均远小于0.01);在23例良性g-CHM和10例侵袭性g-CHM中:CSF1PO座位的等位基因10、11在良性中的出现率高于在侵袭性g-CHM中(P=0.026148),等位基因12在良性中的出现率低于在侵袭性g-CHM中(P=0.023879);TPOX座位的等位基因8在良性中的出现率高于在侵袭性g-CHM中(P=0.004322),而等位基因11在良性中的出现率低于其在侵袭性g-CHM中(P=0.008671)。上述结果提示,葡萄胎基因组中存在某些等位基因分布与在人群中的分布不同,而且葡萄胎是否具有侵袭性也和某些等位基因的出现率过高或过低有相关性,这些与侵袭性有关的等位基因可能成为预测葡萄胎是否具有侵袭性的标志物。  相似文献   
147.
本文采用整群抽样的方法,对湖南两地区城乡共2377人(15岁以上)的成瘾物质使用状况进行调查,其中男1179(49.6%)人,女1199(50.4%人),平均年龄男女分别为41.2(SD=17.5)和43.4(SD=18.6)。结果表明,饮酒率男性为57.5%,女性为17.3%,吸烟率男女分别为68.2%和11.7%;饮酒者多集中在每月饮1次左右的人群中(男57.9%,女77.9%),但吸烟者多集中在每日吸20支及以上(男52.4%,女42.9%)的人群中。除解热镇痛剂外,男性各种精神活性物质的使用频率及剂量皆男高于女性,开始使用的年龄及成瘾的年龄男性低于女性;性别、使用频度、最早使用的年龄、婚姻与饮酒、吸烟量关系最为密切。有14人使用过鸦片类物质,4人使用过兴奋剂。作者讨论了我国成瘾物质使用的特点,指出经济水平、社会文化背景等因素与我国社会性成瘾物质的使用有密切关系。  相似文献   
148.
A study of the x-ray sensitivity of amorphous selenium (a-Se) for digital mammography has been performed. A uniform layer of a-Se was deposited on a glass substrate with electrodes on both surfaces. The deposition procedure was identical to that used for a-Se flat-panel detectors. A high voltage was applied to the top surface of the a-Se layer in order to establish an electric field E(Se). Then the sample was exposed to x rays with 27 kVp spectra generated from an x-ray tube with a molybdenum (Mo) target. The mean x-ray energy of the spectrum used was approximately 16.6 keV. The x-ray current generated by the a-Se layer was measured as a function of E(Se). From the current measurement and the estimation of total x-ray energy absorbed in the a-Se, the energy required to create one electron-hole pair (EHP), W, was determined as a function of E(Se). It was found that at the most commonly used E(Se) of 10 V/microm, W was measured as 64 eV. This is considerably higher than the widely accepted typical value of W = 50 eV measured at higher x-ray photon energies (e.g., 50 keV). The dependence of W as a function of E(Se) can be best fitted using the empirical expression of E(Se)-gamma. This relationship is consistent with the results obtained at higher x-ray energies. This article provides an accurate measurement of x-ray sensitivity of a-Se at mammographic energies independent of detector operation, such as the most recently developed flat-panel detectors. The results will be a useful tool for investigation and optimization of a-Se-based x-ray imaging detectors, such as determination of pixel fill-factor and optimal E(Se) during operation.  相似文献   
149.
150.
Orally induced tolerance is a physiologically relevant form of peripheral tolerance, which is believed to be important for the prevention of pathological immune responses in the gut. Of several mechanisms proposed to mediate oral tolerance, one that has received much attention recently is the concept of regulatory CD4+ T cells. As recent studies have suggested that interleukin (IL)-15 may be important for the differentiation and maintenance of regulatory CD4+ T cells, we have examined the role of IL-15 in oral tolerance, using a soluble form of the IL-15 receptor (sIL-15R) which blocks the biological effects of IL-15 in vivo. Oral tolerance induced by feeding mice ovalbumin (OVA) in a low-dose regimen believed to induce regulatory T cell activity was not affected by the administration of sIL-15R during either the induction or maintenance phase of tolerance. Thus, oral tolerance does not involve an IL-15-dependent mechanism.  相似文献   
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