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991.
汉族男子体格及生殖器发育特点 总被引:1,自引:0,他引:1
2411例汉族男性大学生体格和生殖器的测量结果如下:阴茎周径8.17±0.64cm,阴茎长度7.43±1.04cm,阴茎牵长13.33±1.19cm,右睾丸容积17.91±4.09ml,左睾丸容积17.83±4.05ml,身高171.07±5.66cm,体重58.43±7.75kg.北方学生体格和生殖器发育均优于南方.城、县、乡学生的生殖器发育无明显差异,但城市学生体格发育优于农村.16岁后阴茎、睾丸大小变化不大,但生殖器的发育可持续到30岁. 相似文献
992.
X M Lu A J Fischman E Stevens T T Lee L Strong R G Tompkins M L Yarmush 《Journal of immunological methods》1992,156(1):85-99
Monoclonal antibody-Sn-chlorin e6 immunoconjugates were prepared by the site-selective covalent modification of the monoclonal oligosaccharide moiety. By carefully controlling the reaction conditions and introducing triethanolamine groups as axial ligands of the Sn moiety, conjugates with in vivo biodistribution properties similar to underivatized IgG were prepared. By varying the reaction conditions, conjugates were reproducibly prepared with a range of photosensitizer to mAb molar ratios from 1.6 to 10. Based on a competitive inhibition radioimmunoassay, conjugates prepared by this method showed selectivity and binding affinity comparable to the unmodified antibody. The immunoconjugates had only slightly lower singlet oxygen yields than that observed with the Sn-chlorin e6 precursor indicating that negligible aggregation or structural modification of the chromophores occurred during the synthesis process. In vitro cell killing experiments demonstrated that all conjugates possessed significant cytotoxic activity. Biodistribution studies in mice showed that conjugates prepared with axial ligands had significant serum retention 24 h after injection while conjugates prepared without the triethanolamine ligand were much more rapidly cleared. In vivo specificity was demonstrated using rats infected with Fisher immunotype I P. aeruginosa at a site in the left posterior thigh muscle. Target to background ratios exceeded 60 at 120 h after conjugate injection of the specific immunoconjugate, compared to a ratio of only 6 for a non-specific mouse IgG conjugate. Biodistribution patterns at 120 h post injection indicate that the conjugates were both biologically active and structurally intact. 相似文献
993.
瘤型麻风动物模型的NK细胞活性的体外测定 总被引:1,自引:0,他引:1
本文报道了瘤型麻风小鼠模型中脾脏NK细胞活性的体外测定,以及加入外源性IL-2对这一活性的影响。结果表明,随着感染时间的延长,小鼠脾脏中NK细胞活性逐渐降低。感染1月小鼠的NK细胞活性明显低于正常小鼠,感染3月小鼠的NK细胞活性较感染1月小鼠更低(P值均<0.01)。将含有IL-2的上清液加入NK细胞活性检测系统中,发现外源性IL-2可逆转感染小鼠的NK细胞活性,使其恢复达正常水平。结合IL-2与NK细胞活性在免疫调节中的作用,对瘤型麻风动物模型的特殊表现作了讨论。 相似文献
994.
S. Patel S. Lu P. C. Doerschuk G. R. Wodicka 《Medical & biological engineering & computing》1995,33(4):571-574
A parametric phase delay estimation technique is used to determine the spatial and inhaled gas composition dependencies of
sound propagation time through an intact human lung at frequencies of 150–1200 Hz. Noise transmission measurements from the
mouth to the extrathoracic trachea and six sites on the posterior chest wall are performed in 11 healthy adult subjects at
resting lung volume after equilibration with air, an 80% helium-20% oxygen mixture, and an 80% sulfurhexafluoride-20% oxygen
mixture. The phase delay, τ(f), exhibits a bilateral asymmetry with relatively decreased delays to the left posterior chest
as compared with the right. The phase delay to lower lung sites is greater than to upper sites at frequencies below 300 Hz;
yet the opposite is found at higher frequencies, indicating changing propagation pathways with frequency. There is no measurable
effect of inhaled gas composition on τ(f) below 300 Hz. At higher frequencies, changes in τ(f) that reflect the relative sound
speed of the particular inhaled gas are observed. These findings support and extend previous measurements and hypotheses concerning
the strong frequency dependence of the acoustical properties of the intact respiratory system. 相似文献
995.
996.
997.
应用模糊极小极大神经网络研究了化合物复杂结构和性能(QSAR)之间的关系,用该法进行几组化合物致癌的识别,结果优于线性回归的方法,对此作出一些分析。 相似文献
998.
阿片肽在后角镇痛的作用机理,被认为是通过突触前抑制一级传入纤维P物质释放的结果,然而始终未获得形态学的证实。鉴于一级传入纤维存在大量阿片受体的事实,曾提出阿片肽突触前抑制可能是通过非突触的轴-轴作用。为了验证这一设想,本文用免疫组化方法,详细观察了大鼠延髓后角浅层亮氨酸脑啡肽(L-ENK)轴突终末的突触结构和胞吐释放。电镜观察显示,延髓后角ENK终末可分为两类,第一类终末除了含圆形小清亮囊泡外,还有较多的大颗粒小泡(一般7个以上),主要分布于Ⅰ层,很少看到此类终末形成突触;第二类终末,一般含较多圆形清亮小泡和少量大颗粒小泡(一般不超过3个),它们分布于Ⅰ层和Ⅱ层,此类终末主要形成轴-树突触和少量的轴-体突触。只见到一例轴-轴突触,其突触后成分为未标记的R型终末,此外还见到ENK阳性树突成为中央终末的突触后成分。在去传入神经条件下,上述各类终末皆可见到ENK阳性大颗粒小泡的胞吐形成,它们皆位于非突触区,而在突触部位可见到清亮小泡胞吐像,上述结果提示后角ENK非突触部位释放可能是哭触后抑制一级传入纤维P物质释放的形态学基础。 相似文献
999.
小鼠ARS腹水型网状细胞肉瘤瘤株加1.5、2.0、2.5%DMSO体外培养,被诱导出现了巨噬细胞样分化。细胞及核缩小,尤以核缩小为著,核质比值下降。2.5%DMSO的作用最显著,核仁缩小仅见于2.5%组。核质比值小于0.5,且核仁亦缩小的细胞近似巨噬细胞。2.5%DMSC使非特异性酯酶阳性细胞增多;Po1ystyrene胶乳颗粒吞噬百分数和吞噬指数亦增高。透射电镜观察,2.5%DMSO处理的、核质比值小于0.5的ARS细胞内,细胞器丰富,Golgi复合体发达,次级溶酶体增多。扫描电镜观察,对照组的大细胞多,表面有多数密集的细长微绒毛。2.5%DMSO处理的ARS,大细胞减少,小细胞增多,微绒毛明显缩短减少。这种小细胞与光镜和透射电镜下观察的小细胞一致,是分化程度较高的巨噬细胞样细胞。2.5%DMSO处理的ARS细胞核分裂指数显著下降。 相似文献
1000.
Incidence and case-fatality rates resulting from the 1998 enterovirus 71 outbreak in Taiwan 总被引:6,自引:0,他引:6
Lu CY Lee CY Kao CL Shao WY Lee PI Twu SJ Yeh CC Lin SC Shih WY Wu SI Huang LM 《Journal of medical virology》2002,67(2):217-223
In 1998, an epidemic of hand-foot-and-mouth disease and herpangina caused by enterovirus 71 occurred in Taiwan, leaving many fatalities and severely handicapped survivors in its wake. The reasons this rather common pathogen would cause such a large-scale epidemic remain unknown. A seroepidemiological survey to elucidate the epidemiological characteristics of this outbreak, including its incidence and case-fatality rates was undertaken. Microneutralization tests for antibodies against enterovirus 71 were used to screen four collections of serum samples: 1) 202 specimens taken from individuals > or = 4 years old in 1994; 2) 245 specimens collected from individuals of all ages in 1997; 3) 1,258 specimens collected from individuals of all ages in 1999; and 4) sera samples from a birth cohort of 81 children who had yearly blood samples taken from 1988-98. After the maternal antibody had declined, the seropositive rates began to increase with age. Approximately half of all children aged 6 years or older were enterovirus 71 seropositive. Significantly higher seropositive rates were noted in 1999 than in 1997, in children aged 0.5-3 years. The incidence of enterovirus 71 infection during the epidemic was estimated to be 13-22%, with the higher rates in younger children. The case-fatality rate was highest (96.96 per 100,000) in infants aged 6-11 months, and declined in older children. The results showed that enterovirus 71 is endemic in Taiwan. The apparent lack of large-scale enterovirus 71 activity in the 3 years before 1998 might have been the prelude to the epidemic's appearance in 1998, and might suggest that enterovirus 71 infection will reappear every few years. The lack of a protective antibody in younger children may account for the high incidence and case-fatality rate in this age group. 相似文献