Fabrication and efficient photocatalytic degradation of methylene blue over CuO/BiVO4 composite under visible-light irradiation

CuO/BiVO₄ composite photocatalysts were prepared by solution combustion synthesis method and impregnation technique. X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scan electron microscopy and UV-vis diffusion reflectance spectra were used to identify the physical properties and photophysical properties of CuO/BiVO₄ composite photocatalysts. The photocatalysts exhibit the enhanced photocatalytic properties for degradation of methylene blue under visible-light (λ > 420 nm). The mechanism of improved photocatalytic activity is also discussed.     

Single-Step Dip Coating of Crack-Free BaTiO3 Films >1 μm Thick: Effect of Poly(vinylpyrrolidone) on Critical Thickness

BaTiO₃ coating films were prepared from Ba(CH₃COO)₂–Ti(OC₃H₇ⁱ)₄–H₂O–CH₃COOH–C₃H₇ⁱOH solutions containing poly(vinylpyrrolidone) (PVP) via single-step, nonrepetitive dip coating. The critical thickness—i.e., the maximum film thickness achieved without crack formation via nonrepetitive dip coating—was successfully increased by incorporation of PVP in the precursor solution. Relatively dense, crack-free BaTiO₃ films >1 μm in thickness were achieved via single-step deposition using a solution containing PVP of average molecular weight of 630 000. Incorporation of an excess amount of PVP, however, led to a decrease in the critical thickness. Higher-molecular-weight PVP was more effective in increasing the critical thickness, whereas N-vinyl-2-pyrrolidone monomers did not affect the critical thickness. Stepwise heating of the gel films resulted in increased optical transmittance of the films, accompanied by film densification.     

Heat transfer characteristics in a two‐dimensional channel with an oscillating wall

Numerical calculations have been carried out for the laminar heat transfer in a two‐dimensional channel bounded by a fixed wall and an oscillating wall. In this calculation, the moving boundary problem was transformed into a fixed boundary problem using the coordinate transformation method, and the fully implicit finite difference method was used to solve the mass, momentum, and energy conservation equations. The calculated results are summarized as follows: (i) The wall oscillation has an effect of enhancing the heat transfer and an effect of increasing the additional pressure loss. (ii) An optimum Strouhal number for the enhancement of heat transfer exists, and this optimum value is strongly affected by the amplitude of wall oscillation. © 2001 Scripta Technica, Heat Trans Asian Res, 30(4): 280–292, 2001     

Esterification effect on the recovery of vitamin E from palm oil refining residues by molecular distillation

Waste edible oils are an alternative source of high-value natural compounds. Vitamin E can be recovered from palm oil refining residues by molecular distillation. However, the presence of other lipophilic molecules compromises the selective separation of vitamin E. Esterification of the free fatty acids can enhance the selective separation of vitamin E by molecular distillation, but the conditions for carrying out the reaction need to be investigated to simultaneously ensure the conversion of free fatty acids and the reduction of vitamin E losses. Thus, this study investigated the effect of the esterification of the industrial waste on the recovery of vitamin E by molecular distillation. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and analysis for fats and oils preconized by the American Oil Chemists' Society (AOCS) were used in the characterization of the industrial waste. Determination of the best condition to carry out the reaction was obtained by a central composite rotational design (CCRD) using the response surface methodology (RSM) and the desirability profile. The results showed that the best condition for the esterification was at 64°C, 213 min, 2 wt.% sulphuric acid, and a 10/1 methanol/free fatty acids molar ratio. This reaction condition achieved 97.9% conversion of free fatty acids and less than 3% of vitamin E loss. The esterification promoted concentration of vitamin E in the residue stream (145.4%) and reduction in the distillate stream (87.8%). Therefore, the obtained results presented a suitable route to obtaining vitamin E concentrate and adding value to an industrial residue.     

Serum Autotaxin is not a Useful Biomarker for Ovarian Cancer

Autotaxin (ATX) is a glycoprotein that was first identified in the conditioned medium of human melanoma cells as an autocrine motility factor. It possesses lysophospholipase D activity, producing the bioactive lipid mediator lysophosphatidic acid (LPA) from lysophosphatidylcholine. Enhanced expression of ATX mRNA has been reported in various cancer cells and tissues, and it has been speculated that ATX overexpression in cancer cells may be associated with aberrant LPA production. LPA and ATX have been implicated in cancer progression and metastasis, and ovarian cancer is a representative example. In the present study, we measured the serum ATX antigen levels in patients with ovarian cancer and evaluated the usefulness of this parameter for clinical laboratory testing. The serum ATX antigen levels were not increased in ovarian cancer patients as compared with the levels in healthy subjects, and the serum ATX may not be useful as a biomarker for ovarian cancer.     

豆酱(日本味噌)含盐量对胃癌及血压的影响

豆酱(日本味噌)是人们喜欢食用的发酵食品,但其所含食盐量较高(日本豆酱含盐量10%～13%),而盐分过量摄入被认为是胃癌、高血压等生活方式疾病的致病因子。日本的免疫学调查表明经常喝酱汤的人,癌症发病率低,为此,笔者做了动物试验,研究了在饵料中,分别以豆酱形式添加食盐与以食盐的形式直接添加对癌症、高血压的影响,以及添加不同发酵时间的豆酱对胃癌的抑制效果。试验结果表明:在盐分含量相同的情况下,以豆酱形式添加食盐的饵料不仅不会增加胃癌的发病率,相反能抑制胃癌的发生,而且随着豆酱发酵时间的延长,对胃癌的抑制效果越强;另外也不会引起血压升高。因此,建议将以豆酱为原料制作的酱汤做为健康食品进行推广。     

Mesoscopic architectures of porous coordination polymers fabricated by pseudomorphic replication

The spatial organization of porous coordination polymer (PCP) crystals into higher-order structures is critical for their integration into separation systems, heterogeneous catalysts, ion/electron transport and photonic devices. Here, we demonstrate a rapid method to spatially control the nucleation site, leading to the formation of mesoscopic architecture made of PCPs, in both two and three dimensions. Inspired by geological processes, this method relies on the morphological replacement of a shaped sacrificial metal oxide used both as a metal source and as an 'architecture-directing agent' by an analogous PCP architecture. Spatiotemporal harmonization of the metal oxide dissolution and the PCP crystallization allowed the preservation of very fine mineral morphological details of periodic alumina inverse opal structures. The replication of randomly structured alumina aerogels resulted in a PCP architecture with hierarchical porosity in which the hydrophobic micropores of the PCP and the mesopores/macropores inherited from the parent aerogels synergistically enhanced the material's selectivity and mass transfer for water/ethanol separation.     

Oximetry of retinal capillaries by multicomponent analysis

Retinal oximetry of capillaries was performed for early detection of retinal vascular abnormalities, which are caused predominantly by complications of systemic circulatory diseases. As the conventional method for determining absorbance is not applicable to capillaries, multicomponent analysis was used to estimate the absorbance spectra of the retinal blood vessels. In this analysis, the capillary spectrum was classified as intermediate between those of the retinal arteries and veins, enabling relative estimation of oxygen saturation in the capillaries. This method could be useful for early recognition of disturbances in the peripheral circulation. Furthermore, a spectroscopic ophthalmoscope system based on the proposed method was developed to examine the human retina. A clinical trial of this system demonstrated that oximetry of the retinal capillaries may be an improvement over the present diagnosis for patients of malignant hypertension.     

Effect of iodine doping of phthalocyanine on the photocurrent generation in a phthalocyanine/C60 heterojunction

Photocurrent generation in an indium-tin oxide (ITO)/iodine-doped Ni-phthalocyanine (NiPc-I_x)/C₆₀/In/Al heterojunction device with x ~ 1 was studied. By keeping the device in air after preparation, the device slowly reached a stationary state in which the sign of the photocurrent is opposite to that of a non-doped ITO/NiPc/C₆₀/In/Al device although the rectification direction for the dark current is the same. By a simulation of incident photon-to-current conversion efficiency spectra and a measurement of internal electric field by electroabsorption spectroscopy, it was elucidated that, in the doped device, the band bending near the phthalocyanine/C₆₀ interface is absent and the photocurrent is generated by a weak Schottky barrier at the C₆₀/In interface. It is also shown that the C₆₀ film encapsulates the doped iodine into the NiPc-I_x layer to stabilize the doping level and prevent the reaction of iodine with In.     

Effects of Baccharin Isolated from Brazilian Green Propolis on Adipocyte Differentiation and Hyperglycemia in ob/ob Diabetic Mice

Propolis is a honeybee product with various biological activities, including antidiabetic effects. We previously reported that artepillin C, a prenylated cinnamic acid derivative isolated from Brazilian green propolis, acts as a peroxisome proliferator-activated receptor γ (PPARγ) ligand and promotes adipocyte differentiation. In this study, we examined the effect of baccharin, another major component of Brazilian green propolis, on adipocyte differentiation. The treatment of mouse 3T3-L1 preadipocytes with baccharin resulted in increased lipid accumulation, cellular triglyceride levels, glycerol-3-phosphate dehydrogenase activity, and glucose uptake. The mRNA expression levels of PPARγ and its target genes were also increased by baccharin treatment. Furthermore, baccharin enhanced PPARγ-dependent luciferase activity, suggesting that baccharin promotes adipocyte differentiation via PPARγ activation. In diabetic ob/ob mice, intraperitoneal administration of 50 mg/kg baccharin significantly improved blood glucose levels. Our results suggest that baccharin has a hypoglycemic effect on glucose metabolic disorders, such as type 2 diabetes mellitus.