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991.
Chlorella pyrenoidosa and activated sludge were co-immobilized with simplifying modified PVA-sulfate method. Effects of light intensity and light:dark ratio on the growth of co-immobilized algae cells and removal of nitrate and phosphate were studied. The results indicate that the growth rate of co-immobilized algae cells reduces when light intensity is decreased from 4000 Lux to 1000 Lux, while optimal light:dark ratio for algal growth is 16:8. The influence of illumination on nitrate removal is so weak that the removal percentage can reach 90 approximately 100% within 12 approximately 24 h during the experimental periods in spite of changing illumination conditions. On the other hand, phosphate removal efficiency reduces when light intensity or light:dark ratio is decreased. The highest phosphate removal percentage is 99.6% under the circumstances of 4000 Lux and full-time illumination in our experiment, while the average phosphate removal is about 78%. The change of pH value in water samples is also observed. When water sample is treated by the co-immobilized system, pH value increases in light and decreases in dark. Microorganisms' physiological action is considered as the main mechanism that leads to the change of pH value.  相似文献   
992.
Keratoconus (KC) is a noninflammatory corneal thinning disorder and the major cause of cornea transplantation in the Western world. Genetic factors have been suggested in the cause of KC. We conducted a family study to investigate genetic contributions to the development of KC by evaluating familial aggregation and testing genetic models with segregation analysis. KC was diagnosed based on clinical criteria. Familial aggregation of KC was evaluated using both clinical status and three videokeratography indices generated by the Topographic Modeling System (TMS-1). The estimated KC prevalence in first-degree relatives was 3.34% (41/1,226, 95% CI: 3. 22-3.46%), which is 15 to 67 times higher than that in the general population (0.23-0.05%). For all three videokeratography indices, CK, IS, and KISA, KC propositi had significantly higher mean values than controls (all P < 0.0001). Clinically unaffected parents also had significantly higher values for these indices than controls (all P < 0.016). The correlation of KISA in sib and parent-offspring pairs (r = 0.30 and 0.22, respectively, both P < 0.0005) was significantly greater than that in marital pairs (r = 0.14), and the latter was not significantly different from zero. We performed segregation analysis on KISA in 95 families ascertained through KC propositi. Hypotheses of both sporadic and environmental models were rejected (P < 0.001); a major gene model was not rejected (P > 0.1). Additionally, the most parsimonious model was autosomal recessive. In conclusion, we observed strong evidence of familial aggregation in KC and its subclinical indices and this aggregation is likely due to a major gene effect.  相似文献   
993.
994.
Late allograft rejection due to transplant vasculopathy continues to be a major clinical problem. Increasing the ratio of donor transplant size to recipient weight has been shown to reduce the incidence of late allograft failure. Using a murine pancreas transplant model we have tested the hypothesis that increasing the donor transplant size in a recipient can promote long-term allograft survival by promoting recovery from transplant vasculopathy. Recipients of an allograft that showed extensive vasculopathy were transplanted with a second donor transplant. The effect of the second allograft on the vasculopathy present in the first graft was measured. Transplanting a second allograft reversed all signs of ongoing rejection, including transplant vasculopathy, resulting in long-term survival of the first graft. Vasculopathy was only reversed if the first and second grafts were from the same mouse strain, suggesting an antigen-specific mechanism. However, the recovery of the first graft was not associated with antigen-specific peripheral tolerance.  相似文献   
995.
人大脑内部微血管构筑——组织化学显示法研究   总被引:2,自引:0,他引:2  
本文应用碱性磷酸酶组织化学对血管内皮的染色方法,光镜观察了3例人大脑内部的微血管构型。结果,皮质短动脉进入皮质内的分枝去向有:1.皮质返枝;2.水平枝;3.下降支。皮质长动脉末端的分枝类型分为:1.血管栅栏样分枝型;2.烛台样或小锚样分枝型;3.树根样分枝型。看到了从微动脉、毛细血管到微静脉的连续性通路。论述了皮质动脉与静脉之间在形态学方面的差别及皮质内血管吻合的几种形式,为更好地理解大脑皮质内微循环类型提供了形态学依据。  相似文献   
996.
我们利用兔抗微管蛋白抗体和兔抗辣根过氧化物酶(HRP)抗血清制备的HRP—抗HRP(PAP)复合物,建立了微管的PAP免疫酶细胞化学方法。应用此法观察到人食管癌ECa 109、胃癌SGC 7901,乳腺癌MCF 7和成骨肉瘤OS 732细胞间期胞质微管减少或消失,只有大量弥散分布的微管蛋白棕色反应产物,在微管组织中心(MTOC)附近十分密集,而正常成纤维细胞和胎儿胃粘膜上皮细胞间期,都有发达的胞质微管结构(CMTC)。在分裂期,这些肿瘤细胞都显示纺锤体微管,与正常细胞比较无明显差异。本研究应用PAP方法进一步证明,以前用免疫荧光细胞化学方法观察到的人肿瘤细胞间期胞质微管缺陷的特征。除去低温(4℃)或秋水仙酰胺处理后,解聚的CMTC又可恢复,表明本方法与免疫荧光染色法,同样具有很高的特异性。本工作在细胞固定及免疫反应的某些步骤上有所改进。  相似文献   
997.
998.
999.
We have examined mixed populations and cloned murine CD4+ T cell lines for their sensitivity to anti-CD3-stimulated suicide. The sensitivity of CD4+ clones to anti-CD3-stimulated suicide is independent of their interleukin-2/interleukin-4 or interferon-gamma secretion profile or their lytic efficiency in anti-CD3 redirected lytic assays.  相似文献   
1000.
The molecular charge on bovine serum albumin (BSA) was modified by substituting carboxyl groups on the protein with ethylenediamine, thereby producing a highly cationic derivative with a pI of 9.3 to 9.5. Gel-filtration studies showed that the molecular weight of BSA was not significantly altered after cationization. When the cationized BSA was administered to rabbits using a chronic serum sickness schedule of injections, the animals developed a membranous glomerulopathy similar to the human disease, except that approximately one-third of the animals also showed focal and segmental endocapillary proliferation. Comparison of the circular dichroism spectra of native and cationized BSA showed that the substitution of the carboxyl groups resulted in a 50% reduction in the alpha-helical content of the native molecule. This conformational change should be considered as a possible determinant of the different immune response and immunopathology associated with the cationized molecule compared with native BSA.  相似文献   
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