The efficacy of RGD modified liposomes loaded with vinorelbine plus tetrandrine in treating resistant brain glioma

Brain glioma is one of the most common and devastating intracranial malignancies with a high mortality. Chemotherapy for brain glioma is not ideal due to blood brain barrier (BBB) and multidrug resistance (MDR). The objectives of the present study were to develop a kind of RGD (Arg-Gly-Asp) tripeptide modified vinorelbine plus tetrandrine liposomes to achieve BBB transportation, MDR reversion and glioma cell targeting simultaneously. The studies were performed on glioma cells, resistant glioma cells and glioma-bearing mice. Results showed that the constructed liposomes with suitable physicochemical properties could significantly enhance the transport across BBB, obviously accumulate in glioma cells, and exhibit evident capabilities in diminishing brain glioma in mice. Action mechanism studies indicated that the enhanced anticancer efficacy could be attribute to the follows: prolonged elimination half-life (7.093?±?1.311?h); increased AUC_0–24?h (28.92?±?2.66?mg/L*h); transporting across BBB; enhanced cellular uptake; down-regulation on P-gp (0.49?±?0.06 fold); inducing apoptosis via activating caspase 8, 9, and 3 (2.40?±?0.22, 3.57?±?0.29, and 4.33?±?0.30 folds, respectively). In conclusion, the RGD modified vinorelbine plus tetrandrine liposomes may offer a promising therapeutic strategy for treatment of brain glioma.     

1982-2015年黄土高原NDVI时空演变及其对气候变化的季节响应

基于GIMMS NDVI、温度和降水数据,利用集合经验模态分解(EEMD)、线性回归分析、偏相关分析等方法分析了1982-2015年黄土高原植被覆盖时空变化及其对气候变化的季节响应。结果表明:年际变化趋势上,1982-2015年黄土高原生长季、春、夏、秋季NDVI均呈显著增长趋势,且各个季节NDVI增加速率逐年升高,尤其以夏季增加速率的变化最为明显;空间上,生长季、春、夏、秋季NDVI均呈由西北向东南递增的趋势,且在大部分地区呈显著上升趋势;线性回归表明,生长季、春、夏、秋季温度均呈显著上升趋势;生长季、秋季降水呈增加趋势,春、夏季降水呈减少趋势。EEMD分析进一步表明,生长季、春、夏、秋季温度均先升高后降低,降水均呈先减少后增加的趋势;空间变化趋势上,温度在生长季、春、夏、秋季大部分地区呈显著上升趋势,降水仅秋季有部分区域呈显著上升趋势;NDVI与温度在黄土高原东北部及西南部地区呈显著正相关,与降水在黄土高原北部及西北部地区呈显著正相关。     

Modeling and mechanism of the adsorption of proton onto natural bamboo sawdust

Natural bamboo sawdust with cellulose-lignin polymeric structure was used as a raw adsorbent to remove heavy metal and dyes in water. The analysis of surface properties showed that high proton affinity sites were mainly composed of phenolic and alcohol hydroxyl, while low proton affinity sites mainly consisted of carboxylic acid, silicon hydroxyl, aluminum hydroxyl and some low densities of sulfhydryl and phosphoryl groups. The results fitted by NEM surface complexation model showed: three-sites model fitted acid-base titration data better than two-sites and one-site model. Acid-base titration experiments showed the amount of acid and base consumed was not uniform between acid and alkali side. This was probably due to the swelling of cellulose in acid side, but the possibility that different reactions occurred in acid and alkali side cannot be completely excluded. Pznpc of sawdust was between pH 5.2 and 5.5.