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从元谋栽培印楝Azadirachta indica的枝叶中分离得到15个化合物,结构类型有三萜、倍半萜、甾体等。经波谱解析鉴定为nimbin(1),6-deacetylnimbin(2),6-deacetylnimbinene(3),nimbinene(4),azadiradi-one(5),7-acetoxy-elema-1,3-dien-8-ol(6),1-naphthalenone(7),acarusnol(8),colvane-2β,9α-diol(9),乌苏酸(10),马斯里酸(11),2α-羟基乌苏酸(12),猕猴桃酸B(13),2α,3α,4β-trihydroxypregnan-16-one(14),2β,3β,4β-trihydroxypregnan-16-one(15)。化合物6~15为首次从该植物中分离得到。  相似文献   
86.
A novel ligand‐assisted assembly approach is demonstrated for the synthesis of thermally stable and large‐pore ordered mesoporous titanium dioxide with a highly crystalline framework by using diblock copolymer poly(ethylene oxide)‐b‐polystyrene (PEO‐b‐PS) as a template and titanium isopropoxide (TIPO) as a precursor. Small‐angle X‐ray scattering, X‐ray diffraction (XRD), transmission electron microscopy (TEM), high‐resolution scanning electron microscopy, and N2‐sorption measurements indicate that the obtained TiO2 materials possess an ordered primary cubic mesostructure with large, uniform pore diameters of about 16.0 nm, and high Brunauer–Emmett–Teller surface areas of ~112 m2 g?1, as well as high thermal stability (~700 °C). High resolution TEM and wide‐angle XRD measurements clearly illustrate the high crystallinity of the mesoporous titania with an anatase structure in the pore walls. It is worth mentioning that, in this process, in addition to tetrahydrofuran as a solvent, acetylacetone was employed as a coordination agent to avoid rapid hydrolysis of the titanium precursor. Additionally, stepped evaporation and heating processes were adopted to control the condensation rate and facilitate the assembly of the ordered mesostructure, and ensure the formation of fully polycrystalline anatase titania frameworks without collapse of the mesostructure. By employing the obtained mesoporous and crystallized TiO2 as the photoanode in a dye‐sensitized solar cell, a high power‐conversion efficiency (5.45%) can be achieved in combination with the N719 dye, which shows that this mesoprous titania is a great potential candidate as a catalyst support for photonic‐conversion applications.  相似文献   
87.

Background

Chemokine (C-C motif) ligand 2 (CCL2), commonly known as monocyte chemoattractant protein-1 (MCP-1), has been implicated in the pathogenesis of many diseases characterized by monocytic infiltration. However, limited data have been reported on MCP-1 in type 1 diabetes (T1D) and the findings are inconclusive and inconsistent.

Methods

In this study, MCP-1 was measured in the sera from 2,472 T1D patients and 2,654 healthy controls using a Luminex assay. The rs1024611 SNP in the promoter region of MCP-1 was genotyped for a subset of subjects (1764 T1D patients and 1323 controls) using the TaqMan-assay.

Results

Subject age, sex or genotypes of MCP-1 rs1024611SNP did not have a major impact on serum MCP-1 levels in either healthy controls or patients. While hemoglobin A1c levels did not have a major influence on serum MCP-1 levels, the mean serum MCP-1 levels are significantly higher in patients with multiple complications (mean = 242 ng/ml) compared to patients without any complications (mean = 201 ng/ml) (p = 3.5×10−6). Furthermore, mean serum MCP-1 is higher in controls (mean = 261 ng/ml) than T1D patients (mean = 208 ng/ml) (p<10−23). More importantly, the frequency of subjects with extremely high levels (>99th percentile of patients or 955 ng/ml) of serum MCP-1 is significantly lower in the T1D group compared to the control group (odds ratio = 0.11, p<10−33).

Conclusion

MCP-1 may have a dual role in T1D and its complications. While very high levels of serum MCP-1 may be protective against the development of T1D, complications are associated with higher serum MCP-1 levels within the T1D group.  相似文献   
88.
亚临床甲亢和甲减发病的实验室调查   总被引:2,自引:1,他引:2  
目的 探讨本地区亚临床甲状腺疾病的发病情况。 方法 随机抽样 2 550例健康体检者作甲状腺功能检测 ,以促甲状腺素 ( TSH)水平异常的检出率来判断亚临床甲状腺疾病的发病率。 结果 亚临床甲亢的检出率为5.4 5% ,亚临床甲减的检出率为 6 .98% ;两种疾病 T3、T4、FT3、 FT4 和 TSH的均数比较具有非常显著性差异 ( P <0 .0 1)。 结论 本地区具有亚临床甲状腺疾病的发病现象 ,亚临床甲减的发病率比亚临床甲亢稍高  相似文献   
89.
本文研究了白芨中的萜类化合物对血管生成的抑制作用.及其抑制血管生成的可能机制。采用萃取和色谱法从白芨中分离和纯化了该萜类化合物。通过鸡胚绒毛囊膜(CAM)和人脐静脉内皮细胞(HUVEC)研究了白芨中萜类化合物及其粗提物对血管及血管内皮细胞的抑制作用。结果表明,含该萜类的粗提物显著抑制鸡胚绒毛尿囊膜血管生成;该萜类纯品能明显抑制HUVEC增殖,且可诱导HUVEC凋亡,包括细胞体积缩小,细胞膜起泡,细胞核裂解,染色质浓缩和边集,出现凋亡小体,DNA降解。因此.白芨萜类化合物的抗血管生成作用与诱导血管内皮细胞凋亡有关。  相似文献   
90.
The effects of Aluminum (Al) exposure on immune functions of cultured splenic T and B lymphocytes of rats were studied. The lymphocytes were isolated from spleen of healthy male Wistar rats weighing 110-120 g. The cultured cells in RPMI-1640 medium were exposed to 0 (control group), 0.035 (low-dose group), 0.07 (medial-dose group), and 0.14 (high-dose group) mg/mL Al(3+) as aluminum trichloride (AlCl(3)) in an incubator under 5% CO(2) at 37°C for 24 h. The T and B lymphocyte proliferation was measured with a tetrazolium dye colorimetric assay. The levels of interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α were determined by iodine [(125)I] IL-2, IL-6, and TNF-α radioimmunoassay kits, respectively. The proportions of CD3(+), CD4(+), and CD8(+) T lymphocytes were measured with a flow cytometer. The results showed that the T and B lymphocyte proliferation, the levels of IL-2, IL-6, TNF-α, the proportions of CD3(+) and CD4(+) T lymphocytes, and the ratio of CD4(+)/CD8(+) T lymphocytes were lowered by Al treatments, while the proportion of CD8(+) T lymphocytes was increased. These findings indicate that Al exposure can inhibit the immune functions of splenic T and B lymphocytes of rats in vitro.  相似文献   
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