Triptolide inhibits ovarian cancer cell invasion by repression of matrix metalloproteinase 7 and 19 and upregulation of E-cadherin

Triptolide, a compound extracted from the traditional Chinese medicine preparation of Tripterygium wilfordii Hook F., has been reported to have anti-inflammatory and anti-cancer activities. However, its effect on ovarian cancer invasion is unknown. We observed that MMP7 and MMP19 expression increased in ovarian cancer tissue. Triptolide treatment inhibited the migration and invasion of ovarian cancer cells SKOV3 and A2780 at the concentration of 15 nM. We also observed that triptolide suppressed MMP7 and MMP19 promoter activity in a dose-dependent manner, down-regulating the expressions of these promoters on mRNA and protein level. Moreover, triptolide enhanced E-cadherin expression in ovarian cancer cells. In vivo, triptolide inhibited tumor formation and metastasis in nude mice, and suppressed MMP7 and MMP19 expression; it also enhanced E-cadherin expression in tumor in a dose-dependent manner. Over expression of MMP7 and MMP19, or suppression of E-cadherin expression partially abolished the inhibitory effect of triptolide on invasion of ovarian cancer cells. To summarize, triptolide significantly inhibited the migration and invasion of ovarian cancer cells by suppression of MMP7 and MMP19 and up-regulation of E-cadherin expression. This study shows that triptolide is a good candidate for the treatment of ovarian cancer and reduction of metastasis.     

An Amine-Functionalized Titanium Metal-Organic Framework Photocatalyst with Visible-Light-Induced Activity for CO(2) Reduction

Let your light shine: The photocatalytic reduction of carbon dioxide to the formate anion under visible light irradiation is for the first time realized over a photoactive Ti-containing metal-organic framework, NH(2) -MIL-125(Ti), which is fabricated by a facile substitution of ligands in the UV-responsive MIL-125(Ti) material (see scheme; TEOA=triethanolamine).     

Determination of commonly used azole antifungals in various waters and sewage sludge using ultra-high performance liquid chromatography–tandem mass spectrometry

Sensitive and reliable methods have been developed and validated for determination of commonly consumed azole antifungal pharmaceuticals (clotrimazole, econazole, ketoconazole, and miconazole) and biocides (propiconazole and tebuconazole) in various waters and sewage sludge. Solid phase extraction (SPE) combined with ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) was used to determine the azole antifungals in waters. Azole antifungals in sewage sludge were extracted with ultrasonic-assisted extraction, followed by SPE cleanup and UHPLC–MS/MS detection. Quantification was performed by internal standard calibration in multiple reaction monitoring mode. Recoveries were mostly in the range of 52–110% with relative standard deviations generally within 20%. Method quantification limits were 0.5–6 ng L⁻¹ in waters and 3–9 ng g⁻¹ dry weight (dw) in sewage sludge, respectively. The methods were applied to determine the azole antifungals in wastewater, river water, sediment, and sewage sludge sampled from the Pearl River Delta, China. Clotrimazole, ketoconazole, and miconazole were widely detected at low ng L⁻¹ in waters, low ng g⁻¹ dw in river sediment, and low μg g⁻¹ dw in sewage sludge. The methods can provide valuable tools for investigating occurrence and fate of the azole antifungals in the environment.     

一类φ-强增生型变分包含解的存在和逼近问题

研究Banach空间中一类带有φ-强增生型映象的集值变分包含解的存在性及其具随机误差的Ishikawa迭代逼近问题,得到了迭代序列强收敛于变分包含问题的唯一解的若干等价条件,所得结果统一和推广了一些文献中的最新成果.     

斯托克斯阻力公式的简单推导

斯托克斯阻力公式的传统推导有些复杂.本文根据线性齐次微分方程所满足的叠加原理提出了一个简单的推导.由于斯托克斯方程是一个二阶线性偏微分方程,根据球表面的两个速度分量条件,方程应该有两个线性独立的和完备的解,这两个解应该构成方程的基本解组,它们的线性组合应该就是方程的通解.使用拉普拉斯方程的解以及量纲分析,找到了这两个解.这两个解的线性组合就是斯托克斯问题的解.     

A simple derivation of the Stokes formula of the drag

斯托克斯阻力公式的传统推导有些复杂.本文根据线性齐次微分方程所满足的叠加原理提出了一个简单的推导.由于斯托克斯方程是一个二阶线性偏微分方程,根据球表面的两个速度分量条件,方程应该有两个线性独立的和完备的解,这两个解应该构成方程的基本解组,它们的线性组合应该就是方程的通解.使用拉普拉斯方程的解以及量纲分析,找到了这两个解.这两个解的线性组合就是斯托克斯问题的解.     

偶氮染料刚果红在水中的光催化降解过程

 通过研究在间歇悬浮体系中直接偶氮染料刚果红在水中的光催化降解过程,确定了最佳降解条件. 同时测定了染料溶液的脱色率、COD去除率和矿化率以考察降解过程中脱色与矿化的关系. 另外,对降解过程中溶液pH值的变化及反应的可能中间体进行分析,结果表明: 刚果红染料分子的光催化降解过程分为脱色和矿化两个阶段. 矿化主要发生在脱色结束以后, 并且伴随着脱色溶液的酸化现象. 脱色过程进行较快,完全脱色后形成的中间产物需要较长时间才能被逐步矿化.     

Preparation and catalytic properties of a bimetallic Sn?Pt complex in the supercages of NaY zeolite by use of surface organometallic chemistry

The grafting reaction of SnMe₄ on the surface of Pt/NaY zeolite was investigated in a 1.6 × 10⁴ Pa hydrogen atmosphere. The chemical compositions, structure and properties of the resulting solid were characterized by in situ FTIR, ICP, XRD, XPS, temperature programmed decomposition and nitrogen adsorption. The results show that Pt atoms of Pt/NaY zeolite react with tetramethyltin to form a bimetallic Me₃Sn? Pt surface species in the presence of hydrogen at 353 K. The reaction does not destroy the zeolite framework, while its surface properties are changed. The BET surface area and the pore volume of the zeolite decrease significantly. The CO chemisorption results and the XPS results show that the electronic properties of the modified Pt atoms on the surface of NaY zeolite are altered remarkably by the inductive effect of electron between Pt and methyl groups. The grafted product has excellent selective hydrogenation of furfural to furfuryl alcohol. Copyright © 2007 John Wiley & Sons, Ltd.     

稀土镍磷非晶合金的PAS和DSC研究

文中报导了在Ｎｉ－Ｐ非晶合金中掺入稀土元素钇（Ｙ）的诱导共沉积方法；并通过正电子湮没寿命谱和示差扫描量热计研究了Ｎｉ－Ｐ－Ｙ非晶合金的缺陷态及热稳定性；还从不同角度讨论了稀土元素对该合金热稳定性的贡献。