Mesoporous silica nanoparticles loading doxorubicin reverse multidrug resistance: performance and mechanism

Multidrug resistance (MDR) is one of the major obstacles for successful chemotherapy in cancer. One of the effective approaches to overcome MDR is to use nanoparticle-mediated drug delivery to increase drug accumulation in drug resistant cancer cells. In this work, we first report that the performance and mechanism of an inorganic engineered delivery system based on mesoporous silica nanoparticles (MSNs) loading doxorubicin (DMNs) to overcome the MDR of MCF-7/ADR (a DOX-resistant and P-glycoprotein (P-gp) over-expression cancer cell line). The experimental results showed that DMNs could enhance the cellular uptake of doxorubicin (DOX) and increase the cell proliferation suppression effect of DOX against MCF-7/ADR cells. The IC(50) of DMNs against MCF-7/ADR cells was 8-fold lower than that of free DOX. However, an improved effect of DOX in DMNs against MCF-7 cells (a DOX-sensitive cancer cell line) was not found. The increased cellular uptake and nuclear accumulation of DOX delivered by DMNs in MCF-7/ADR cells was confirmed by confocal laser scanning microscopy, and could result from the down-regulation of P-gp and bypassing the efflux action by MSNs themselves. The cellular uptake mechanism of DMNs indicated that the macropinocytosis was one of the pathways for the uptake of DMNs by MCF-7/ADR cells. The in vivo biodistribution showed that DMNs induced a higher accumulation of DOX in drug resistant tumors than free DOX. These results suggested that MSNs could be an effective delivery system to overcome multidrug resistance.     

一种应用于氢能产业一体化的新型多功能盐穴储氢库

为实现“双碳”目标,解决氢能大规模储存难题,结合我国氢能发展趋势,首次提出了包含盐穴储氢库的三种发展情景下的氢能“制-储-用”一体化方案：①情景一为盐穴储存绿氢,用以燃料电池及炼钢炼铁领域的应用;②情景二为盐穴储存绿氢及CO2-O2混合气体,用于地面合成甲烷及甲烷富氧燃烧发电;③情景三为盐穴储存合成甲烷,用以除发电以外的其他用途。从盐穴储氢库全生命周期的角度,分析了储氢库在三种发展情景下的作用,首次提出了多功能储氢库的概念：可起到废电利用、电力平衡、氢能安全高效储存、CO2减排等多项作用。以昆明市安宁盐矿及云南省为例,结合云南省水电为主的电力结构,分析了多功能盐穴储氢库在情景一、二中的建设需求：①情景一,采用绿氢直接炼钢炼铁工艺,需电解绿氢约60万吨,配套多功能盐穴储氢库总气量1.3亿m3,可实现昆钢减排1307吨;②情景二,针对云南未来电力季节性缺额问题,假设甲烷富氧发电厂提供半年枯期电力,装机200MW,仅需建设多功能盐穴储氢库总库容478万m3,可消纳水电5.34亿度,提供枯期发电量2.88亿度。     

水热预处理竹子促进酶解的效果及其影响因素

采用间歇式水热预处理装置,研究了水热预处理用于竹子的酶解规律,探讨了不同温度、处理时间、纤维素酶添加量及原料种类对促进竹子酶解的效果及其影响。结果表明水热预处理能显著提升竹子的酶解率,在优化条件190℃、10 min水热预处理,添加15 FPU·(g葡聚糖)^-1纤维素酶,72 h葡聚糖与木聚糖酶解率分别为74.3%、54.0%,提高到原来的3.5倍和4.7倍。过高的预处理温度与过长的预处理时间都将导致木糖大量降解和部分葡萄糖降解,使单糖总量下降。纤维素酶的添加量从15 FPU·(g 葡聚糖)^-1提高到60 FPU·(g 葡聚糖)^-1,可使未作预处理和水热预处理竹子的总糖回收率分别提高21.5%和9.9%,其促进酶解的作用远低于预处理的效果,通过预处理增大酶的可及性是提高酶解率的关键。水热预处理对于生物质原料具有选择性,不同的竹子原料具有显著不同的效果。     

准噶尔盆地车排子地区白垩系沉积特征及演化

利用钻井、测井、录井和地震等资料,分析岩石结构构造和古生物,研究准噶尔盆地车排子地区白垩系沉积相发育特征.结果表明:研究区白垩系主要发育扇三角洲相和湖相,可以划分为扇三角洲平原﹑扇三角洲前缘和滨浅湖亚相,以及水上分流河道、漫滩沼泽、水下分流河道、水下分流河道间、席状砂、泥滩、滩坝微相.总体为滨浅湖沉积背景,西北部为隆起区,提供物源,向东、南方向逐渐演化为宽缓的斜坡,碎屑物质主要沉积于斜坡的滨浅湖区.从清水河组到连木沁组沉积范围不断往西南部扩大.受湖平面升降、气候变化、沉积物供给等因素的影响,扇三角洲砂体规模较小,滩坝砂体广泛发育,砂体紧靠生油凹陷,是油气聚集的有利场所,易于形成下生上储型油藏,是油气勘探的重要目标.     

基于ZigBee技术的电压采集系统的设计与实现

在智能低压电器的实际应用中,经常需要进行电压的采集,而有线采集的方法在某些场合中并不适用。提出基于ZigBee无线技术的电压采集系统的设计,利用STM32W无线射频ZigBee单片机作为主控制器,实现0～21V直流电压的采集。     

温度和氧对啤酒老化的影响

研究了4℃、20℃和38℃三种温度条件下,不同溶解氧含量的啤酒其老化物质和香气成分的变化。贮存6个月后有关风味稳定性指标结果如下:贮存温度升高时5-羟甲基糠醛(5HMF)含量显著增加,从20℃到38℃增加了244%,氧含量对5HMF影响很小。TBN变化与5HMF相似,但不如5HMF敏感,从20℃到38℃只增加了5.3%。色度随着氧和贮存温度的增加而增加,38℃贮存的溶氧高的啤酒比4℃对照啤酒色度增加了3.18EBC。DPPH还原力随着贮存温度的升高而下降。贮存期间,对主要挥发性香气的跟踪分析表明,双乙酰在贮存过程持续增加,溶氧高的啤酒其含量更高,贮存2个月后,含量达到其风味阈值,导致啤酒产生“双乙酰”味。乙酸乙酯和乙酸异戊酯在贮存过程含量下降,38℃贮存6个月后,2种酯含量比4℃对照分别降低了18%和21%,溶氧高的啤酒降低程度更大,将会影响啤酒的香气。因此,减少成品啤酒的溶解氧含量,降低贮存温度,可以提高啤酒的抗老化能力。     

An emulsification–solvent evaporation route to mesoporous bioactive glass microspheres for bisphosphonate drug delivery

Regular spherical mesoporous bioactive glass microspheres (MBG-MSs) with tunable SiO₂–CaO–P₂O₅ composition and adjustable mesoporous structure have been synthesized by a new approach of emulsification and solvent evaporation-induced self-assembly. Less ordered mesostructure and enhanced bioactivity resulting from the addition of CaO are investigated through scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction characterizations. The MBG-MSs have high storage capacities and sustained release patterns of anti-osteoporosis (alendronate sodium, NaAL) drugs which are hardly absorbed via oral administration. Furthermore, to some extent the dosage and release rate could also be controlled by CaO content. Cell viability and proliferation assay with rabbit bone marrow stromal cells indicates a positive effect of the CaO/P₂O₅ components on improving the cell growth cumulatively in about 2 weeks.     

硫酸盐镀锡液中2—萘酚的测定

用吸光光度法直接测定了硫酸盐镀锡液中２－萘酚的含量．此方法无需经萃取、分离等复杂手段，也没有添加辅助试剂．方法简便，准确度高，相对误差≤±１３％．     

浅析“摆线铣”高速加工在壳体密封槽加工中的应用

针对壳体端面密封槽加工效率低下的现状,通过分析走刀路径与刀具受力的关系,提出一种高效加工端面密封槽的解决方案.     

工程测量技术在工程建筑中的应用研究

在工程建设施工过程中,对于工程建筑施工前的工程测量的准备工作显得非常重要。尤其对于大型工程建设,以及测量空间合理化等诸多方面的要求。本文通过对当前工程建筑测量中存在的问题以及测量技术发展地研究提出了一些自己的看法和意见。