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A pure mesoporous SrTiO3 with a honeycomb pore structure is synthesized by the sol-gel method and applied to catalyze transesterification of palm oil with methanol for the biodiesel production. The catalyst is characterized by XRD, CO2/NH3-TPD, N2 adsorption-desorption, SEM-EDX, Raman and XPS to reveal its catalytic performances. The highest FAME yield of 93.14% is achieved in transesterification with the molar ratio of methanol to oil of 15:1 and catalyst concentration of 6 wt% at 170 C for 3 h. Besides, the catalyst is highly tolerant of FFAs and moisture, where the FAME yields of 83.80% and 86.50% are achieved even with the oleic acid and water addition of 10 wt% and 5 wt%. Meanwhile, the catalyst is found to be an effective catalyst for the simultaneous esterification and transesterification. The molecular simulation results show that the Ti sites are more easily attacked by FFAs and the Sr active sites are thus retained for the adsorption of methanol to catalyze transesterification, which explains the bifunctionality of the catalyst.

本研究采用密度泛函理论（DFT）研究了在γ-Fe2O3表面HCl对Hg0的吸附和催化氧化的作用机制。构建了Hg0、HCl、HgCl和HgCl2在γ-Fe2O3(001)表面的吸附模型，分析了HCl对γ-Fe2O3表面催化氧化Hg0的作用机理，并通过反应路径的能量分布测定，研究了γ-Fe2O3表面Hg0的氧化过程。结果表明，Hg0倾向于化学吸附在γ-Fe2O3(001)表面Feoct位。HCl在催化剂表面进行解离吸附，形成吸附态Cl和羟基，从而促进Hg0的吸附。HgCl以分子形式化学吸附在γ-Fe2O3(001)上，并作为Hg0氧化过程的中间体。HgCl2倾向在γ-Fe2O3表面上的平行吸附。同时，HCl在γ-Fe2O3(001)上氧化Hg0遵循L-H机理，即化学吸附的Hg0与解离吸附的HCl反应，且HCl对Hg0的非均相氧化通过两步反应途径进行，即Hg0 (ads)→HgCl(ads)→HgCl2(ads)。

A molecular modeling based on the density functional theory (DFT) and the transition state theory (TST) was performed to investigate the influence of biomass gas CO on the N2O decomposition catalyzed by CaO during reburning in the circulating fluidized bed boiler. The model for N2O adsorption onto the CaO(100) surfaces were constructed; and the processes of the N2O decomposition on the CaO(100) surface and the surface recovery of CaO(100) were investigated. The results illustrate that the energy barrier of N2O decomposition on the CaO(100) surface is much lower than that in homogeneous case, and CaO is therefore able to catalyze the N2O decomposition. The atomic O from N2O decomposition can poison the active sites O atom on the CaO(100) surface, while biomass gas CO can promote the regeneration of the active sites on the surface of CaO(100), which is beneficial for CaO to catalyze the N2O removal.

Tamoxifen (TMX) is an antiestrogen drug that is used in the treatment and prevention of all stages of estrogen-dependent breast cancer. Adverse effects of TMX include hepatotoxicity. In this study, we investigated the therapeutic effects of osthole, isolated from medicinal plants especially Fructus Cnidii, on TMX-induced acute liver injury in mice. Mice were injected with osthole (100 mg/kg, ip) or vehicle, followed by TMX (90 mg/kg, ip) 24 h later. We showed that a single injection of TMX-induced liver injury and oxidative stress. Pretreatment with osthole attenuated TMX-induced liver injury evidenced by dose-dependent reduction of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Pretreatment with osthole also blunted TMX-induced oxidative stress, evidenced by significant increase of reduced glutathione (GSH) as well as reduction of malondialdehyde (MDA) and hydrogen peroxide (H(2)O(2)). Consistently, osthole significantly enhanced the expressions of antioxidant genes (GPX1, SOD2, GCL-c, and G6pdh), but suppressed those of pro-oxidant genes (NOX2 and ACOX). Furthermore, osthole inhibited the production of inflammatory cytokines, reduced the metabolic activation of TMX, and promoted its clearance. We further revealed that osthole elevated hepatic cAMP and cGMP levels, but inhibition of PKA or PKG failed to abolish the hepatoprotective effect of osthole. Meanwhile, prominent phosphorylation of p38 was observed in liver in response to TMX, which was significantly inhibited by osthole. Pretreatment with SB203580, a p38 inhibitor, significantly attenuated TMX-induced increase of ALT and AST activities, reduced oxidative stress, and reversed the alterations of gene expression caused by TMX. Moreover, pretreatment with L-buthionine sulfoximine (BSO), an inhibitor of GSH synthesis, partly reversed the effect of osthole on TMX-induced liver injury. Consistently, pretreatment with N-acetyl-L-cysteine (NAC) significantly attenuated TMX-induced increase in ALT and AST activities. Notably, both BSO and NAC had no detectable effect on the phosphorylation levels of p38. Collectively, our results suggest that osthole prevents TMX hepatotoxicity by suppressing p38 activation and subsequently reducing TMX-induced oxidative damage.

The potential of using the waste from simultaneous NOx and SO2 purification bio-trickling process to leach copper ore and to make fertilizer was investigated. It was found there were two main exhausted by-products in the purification process: the acidic liquid in desulfurization tower and the alkalescent liquid in denitrogenation tower. Through operation of leaching the oxide ore sample containing 2.58% copper by the acidic liquid, the effective grade of the metal to be extracted reached 28.37% by weight. With adding proportional dose of ammonia into the alkalescent liquid or the acidic liquid and going through evaporation and concentration, crystal products of ammonium sulfate and ammonium nitrate were generated, which can be used in fertilizer manufacturing.

A quantitative analysis method based on near infrared (NIR) spectroscopy was developed for determining the azithromycin content and its degradation product impurity (decladinosylazithromycin) in azithromycin for injection. Two quantitative models were obtained by evaluating 18 laboratory samples and 44 commercial samples formulated as hydrochlorate, phosphate, lactate and citrate salts. The samples had an azithromcyin content ranging from 74.2% to 91.0% (w/w) and decladinosylazithromycin ranging from 0.1% to 7.7% (w/w). The root mean square error of cross-validation for the azithromycin model and decladinosylazithromycin model were 1.54% and 0.49%, respectively. The estimated limit of detection and limit of quantification for the decladinosylazithromycin calibration were about 1.2% and 4.1% (w/w), respectively. In addition, the quantitative models were validated in terms of specificity, linearity, accuracy, repeatability and intermediate precision, according to the International Conference on Harmonisation guidelines, by evaluating the characteristics of the NIR spectra. The results showed that the models were satisfactory. Our results demonstrated that a universal quantitative model based on NIR diffuse reflectance spectroscopy could be used as a quick and reliable method for quality control of low-dose impurities in pharmaceutical drugs.

Borax, a boron compound and a salt of boric acid, is known to inhibit the growth of tumor cells. HepG2 cells have been shown to be clearly susceptible to the anti-proliferative effects of borax. However, the specific mechanisms regulating this effect are poorly understood. This study aimed to investigate the pathways underlying the growth inhibition induced by borax in HepG2 cells. The effects of borax on HepG2 cell viability were characterized using MTT. Apoptosis was also verified by annexin V/propidium iodide staining. JC-1 dye and western blotting techniques were used to measure mitochondrial membrane potential and p53, Bax, and Bcl-2 protein expression, respectively. Relevant mRNA levels were measured by qRT-PCR. Borax inhibited the proliferation of HepG2 cells in a time- and dose-dependent manner in vitro. The apoptotic process triggered by borax involved the upregulation of p53 and Bax and the downregulation of Bcl-2, which was confirmed by a change in the mitochondrial membrane potential. These results elucidate a borax-induced apoptotic pathway in HepG2 cells that involves the upregulation of p53 and Bax and the downregulation of Bcl-2.

The title compounds were obtained from the reactions of copper or silver monohalides with the bidentate bis(diphenylphosphino)methane (dppm) ligand at room temperature in a mixed solvent. Single-crystal X-ray diffraction analyses indicate that both compounds crystallize in a monoclinic system but in different space groups. The structures are characterized by a trinuclear [M3I2(dppm)3]+ cation with a trigonal-bipyramid [M3(μ 3-I)2] core. In agreement with the geometric characteristics of the M3 triangles, 31P NMR spectra exhibit a single peak for the [Cu3] cluster but a double-peak for the [Ag3] cluster. Preliminary optical studies by UV/Vis and emission techniques show major absorption shoulders at ∼286 nm for Cu3I2(dppm)3·I and ∼254 nm for Ag3I2(dppm)3·I, but no luminescence in the non-degassed MeCN solution at 298 K. The structures, bonding, electronic excitations and emissions are discussed based on relativistic density functional theory calculations.

The title compound, C6H6N4S4, is formed through the thionato S—S bonding of parent 2-mercapto-5-methyl-1,3,4-thia­diazole mol­ecules, following the deprotonation of thiol groups in a mixed solvent. The title compound crystallizes in the monoclinic system, space group C2/c. The S—S distance is 2.028 (1) A, typical of a single bond. The two 1,3,4-thia­diazo­le rings in the mol­ecule each remain planar, with a dihedral angle of 70.5 (1) A, and are related by a twofold rotation axis through the middle of the S2—S2 bond. The geometric parameters for the parent ligand are also reported, to demonstrate the influence of deprotonation on the ligand dimensions.

The simultaneous desulfurization of 2-mercapto-5-methyl-1,3,4-thiadiazole with CuCl(2) x 2H(2)O via mutual diffusion in solvents results in the isolation of air-stable dark-green crystals of [Cu(H(4)C(3)N(2)S)Cl(2)](n) (approximately 65% yield). The structure is characterized by a unique one-dimensional copper chain bridged by diazine N-N single bonds rather than halogens, in sharp contrast with the halide bridging mode in conventional copper halide coordination polymers. Each Cu(II) ion shows a square planar coordination geometry featuring a strong Jahn-Teller distortion, as also supported by EPR data. The phase follows a Curie-Weiss paramagnetic behavior over 6-300 K. However, the intrachain antiferromagnetic interaction is evident (-2J = 21.1 cm(-1)). Such magnetic coupling is related to the interplay between the Cu(II)-d(x2-y2) and diazine N-N p-orbitals.