The Zinc-Sensing Receptor GPR39 in Physiology and as a Pharmacological Target

The G-protein coupled receptor GPR39 is abundantly expressed in various tissues and can be activated by changes in extracellular Zn²⁺ in physiological concentrations. Previously, genetically modified rodent models have been able to shed some light on the physiological functions of GPR39, and more recently the utilization of novel synthetic agonists has led to the unraveling of several new functions in the variety of tissues GPR39 is expressed. Indeed, GPR39 seems to be involved in many important metabolic and endocrine functions, but also to play a part in inflammation, cardiovascular diseases, saliva secretion, bone formation, male fertility, addictive and depression disorders and cancer. These new discoveries offer opportunities for the development of novel therapeutic approaches against many diseases where efficient therapeutics are still lacking. This review focuses on Zn²⁺ as an endogenous ligand as well as on the novel synthetic agonists of GPR39, placing special emphasis on the recently discovered physiological functions and discusses their pharmacological potential.     

Protective Effects of a New Phloretin Derivative against UVB-Induced Damage in Skin Cell Model and Human Volunteers

The phenolic compound phloretin is a prominent member of the chemical class of dihydrochalcones. Phloretin is specifically found in apple and apple juice and known for its biological properties. We were particularly interested in its potential dermo-cosmetic applications. However, practical limitations of phloretin do exist due to its poor water-solubility. Phloretin was sulfonated with sulfuric acid (98%, wt) and mixed with saturated salt water to produce phloretin 3'',3-disulfonate in order to increase its water-solubility. Here we reported the photoprotective effect of phloretin 3'',3-disulfonate (PS), a new semi-synthetic derivative of phloretin. Results showed that PS attenuated cyclobutane pyrimidine dimer (CPDs) formation, glutathione (GSH) depletion and apoptosis induced by ultraviolet B (UVB). The photoprotective effect of PS is tightly correlated to the enhancement of nucleotide excision repair (NER) gene expression. Furthemore, PS had inhibitory effects on UVB-induced release of the inflammatory mediators, such as IL-6 and prostaglandin-E₂. We also confirmed the safety and clinical efficacy of PS on human skin. Overall, the results demonstrated significant benefits of PS on the protection of keratinocytes against UVB-induced injuries and suggested its potential use in skin photoprotection.     

宋代建窑兔毫盏探析

兔毫盏是宋代建窑最具特色的代表性瓷器之一,本文以福建建窑窑址、窑炉和兔毫盏等实物为切入点,系统梳理了宋代建窑兔毫盏的器形、釉面、瓷胎、圈足、底款等特点,并通过对当时人文环境的介绍分析,阐述了兔毫盏能成为一代名瓷的一家之见及当代以宋朝兔毫盏为起点的产品工艺开发现状。     

Salen Mn(III)/NBS催化次氯酸钠氧化4,4’-二羟基二环己烷合成4,4’-二环己酮

以Salen-Mn(III)为催化剂、NBS为溴源构建了一种催化体系,以次氯酸钠为氧化剂成功地将4,4''-二羟基二环己烷氧化为4,4''-二环己酮。分别考察了催化剂Salen Mn(III)、NBS以及次氯酸钠用量对反应的影响,发现当4,4''-二羟基二环己烷为0.5 mmol、Salen-Mn(III) 0.04 mmol、NBS 0.26 mmol、次氯酸钠18 mmol时,在25 ℃反应0.5 h时,4,4''-二羟基二环己烷的转化率和4,4''-二环己酮的选择性分别高达96.1%和93.0%。     

Synthesis and thermal behavior of polymeric precursors for Si?B?C?N ceramic

Polyborosilazanes (PBSZs) were synthesized by co‐ammonolysis of 2,4,6‐trichloroborazine and dichloromethylsilane and used as precursors for Si? B? C? N ceramics. The pyrolyzed products were characterized with Fourier transform infrared, X‐ray photoeletron spectroscopy, thermogravimetric analysis (TGA), X‐ray diffraction, and scanning electron microscopy (SEM). The results indicated the content of B or Si plays an important role in controlling the high temperature behavior of the precursors. The resistance of the ceramics, which were obtained from pyrolysis of PBSZs at 1500°C, toward oxidative attack up to 1000°C was also investigated by TGA and SEM/EDX. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Analysis and Evaluation of Power Formulations for Wood and Hardboard Using Radio Frequency and Microwave Energy

This article analyzes the influence of frequency, temperature, moisture content, and structural orientation on the applicability of the Beer-Lambert law for various wood species using radio frequency and microwave radiation. To achieve this objective, the study compares the power dissipation computed from Maxwell's equation and Lambert's power law. The wood species considered are white oak (Quercus alba), Douglas fir (Pseudotsuga menziesii), trembling aspen (Populus tremuloides), white birch (Betula paperyfera), yellow birch (Betula alleghaniensis), sugar maple (Acer saccharum), and four commercial hardboards. The dielectric constant and dielectric loss factor are examined as a function of moisture conditions, temperature, frequencies, and the three principal structural orientations. The study involved 3,000 complex dielectric constants. It was found that the radial critical thickness is somewhat smaller than the tangential critical thickness (0.95 times smaller) and the longitudinal critical thickness is significantly smaller than the radial (0.52 times). It was demonstrated that the critical thickness L _crit above which the Beer-Lambert law is valid for all of the wood species studied under various conditions obeys the following conditions: log₁₀(L _crt) = 0.999 log₁₀(β^?1) + 0.4122, where β^?1 is the penetration depth (cm). In the case of microwave radiation, the critical thickness can be estimated from L _crt = 2.615 β^?1 ? 0.0626. Finally, a model is proposed to take into consideration the effect of moisture content with frequency (or with attenuation constant).     

Bulk Density,Porosity and Resistance to Airflow of Garlic Slices

ABSTRACT

The bulk density of garlic slices at different moisture levels (ranging from approximately 3 to 65% MC wet basis) was determined by weighing the contents of a container of known volume. The porosity was calculated using its relationship with bulk and apparent densities. An analysis of variance (ANOVA) revealed that bulk density and porosity were affected significantly by moisture and slice thickness as well as the interaction of these variables. Bulk density varied in a positive linear fashion with moisture and thickness while a negative linear correlation was found for the calculated bulk porosity. The linear model met the adequacy criterion for characterising the behaviour of garlic. Using a laboratory unit, the vertical resistance to airflow through the product and the effect of misture and slice thickness were investigated for an airflow rates of 0.09 to 1.2 m₃/s-m₂. A higher resistance to airflow was noted for the wet product with the experimental data fitting to Shedd's model when the aifflow range was divided into two sub-flow rates and to a modified Ergun's equation for the full range.     

Association between Decreased ITGA7 Levels and Increased Muscle α-Synuclein in an MPTP-Induced Mouse Model of Parkinson’s Disease

Parkinson''s disease (PD) is a neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra (SN), reducing dopaminergic levels in the striatum and affecting motor control. Herein, we investigated the potential relationship between integrin α7 (ITGA7) and α-synuclein (α-syn) in the muscle of methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP)-induced mice and C2C12 cells. To characterize the pathology of PD, we examined the expression of tyrosine hydroxylase (TH) in the SN of the midbrain. Compared with the control group, MPTP-treated mice showed a significant decrease in TH expression in the SN, accompanied by a significant decrease in muscle ITGA7 expression. Compared with the control group, α-syn expression was increased in the MPTP group. Furthermore, the pattern of α-syn expression in the MPTP group was similar to the ITGA7 expression pattern in the control group (linear forms). To determine the relationship between ITGA7 and PD, we examined the expression of ITGA7 and α-syn after ITGA7 knockdown using siRNA in C2C12 cells. ITGA7 expression significantly decreased while α-syn expression significantly increased in siRNA-treated C2C12 cells. These results suggest that decreased ITGA7 muscle expression could increase α-syn expression. Moreover, α-syn accumulation, induced by decreased muscle ITGA7, might contribute to PD pathology.     

On the Influence of Permeability and Young's Modulus on the Dehydration of a Strongly Shrinkable Two-Phase Porous Medium: A Model Sensibility Analysis and the Development of a Contact Mechanics Measurement Setup

A model that describes the mass transfer in a two-phase shrinkable porous media by using a classic Darcy law for the fluid relative to solid transfer has been recently developed by Cáceres et al.^[ 1-2 Cáceres , G. ; Bruneau , D. ; Jomaa , W. Two-phase shrinking porous media drying: A modeling approach including liquid pressure gradients effects . Drying Technology 2007 , 25 , 1927 – 1934 . Cáceres , G. Modeling the drying of a saturated shrinkable porous medium: Taking into account the liquid pressure. Ph.D. Thesis, University of Bordeaux, France, 2006 (in French).   ^] This model describes the coupling between the fluid pressure and the solid structure deformation tensor by using the Terzaghi stress tensor decomposition for the media and elastic constitutive law for the solid structure.^{[ 3} Terzaghi , K. Theoretical Soil Mechanics ; John Wiley & Sons : New York , 1943 .[Crossref] , [Google Scholar] ^]

The aim of this article is to point out the sensitivity of this model relative to the two main physical parameters that govern the coupled mass transfer and stress level in a strongly shrinkable porous medium, namely, permeability and the Young's modulus. An experimental setup that makes possible the simultaneous measurement of those two parameters as well as the Poisson ratio is developed in agreement with the recent theoretical suggestions of Lin et al. The experimental evolution of these quantities versus the moisture content is discussed for an agar gel.     

2'-脱氧核糖胞苷的合成工艺

本文报道了2''-脱氧核糖胞苷的一条工业化生产的路线。该工艺路线以α-D-2-脱氧核糖和尿嘧啶为原料,经过甲苷化,酯化,氯代,亲核取代,高效氨化及水解脱保护等6个步骤,总收率44%,经一次重结晶纯化最终产品纯度达到99%以上。此路线条件温和,操作安全,终产物分离纯化简易。目前已经完成公斤级别的中试。     

One‐Pot Palladium‐Catalyzed Synthesis of Selectively Substituted Phenanthridines by Sequential Aryl‐Aryl and Heck Couplings,Aza‐Michael and Retro‐Mannich Reactions

A catalytic synthesis of selectively substituted phenanthridines is achieved through a reaction sequence involving palladium/norbornene‐catalyzed unsymmetrical aryl‐aryl and Heck couplings followed by aza‐Michael and retro‐Mannich reactions. In spite of the many steps involved the method is very simple and allows the formation of selectively substituted phenanthridines under mild conditions in a straightforward one‐pot reaction starting from readily available aryl iodides and bromides.     

水泥生料中氨含量检测方法研究探索

本文主要探究了氯化钾溶液提取法和纳氏试剂法两种方法在水泥生料中氨含量检测的适应性和准确性，并进行了第三方检测验证。研究结果表明，氯化钾溶液提取法适用于0~50 mg/kg浓度的氨含量检测，而纳氏试剂法适用于20~100 mg/kg浓度的氨含量检测，本研究为水泥生料中氨含量检测提供指引和参考，对水泥工业实现氮氧化物超低排放，确保氨逃逸合格有着重要意义。     

Novel one-step formed composite reinforcement of "Spider web like" SiCnw networks and "Z-pins like" SiC rods for ablation resistance improvement of C/C-ZrC-SiC

A novel composite reinforcement with horizontal multilayer "Spider web like" SiC nanowire networks and vertical interconnected "Z-pins like" SiC rods was designed and prepared by facile one-step figuration. The linear ablation rate of "Spider web like" SiC nanowire networks and "Z-pins like" SiC rods collectively reinforced C/C-ZrC-SiC composites at 2610 ± 20 ℃ was 0.4 ± 0.03 μm/s with a 74.19 % reduction. The improved ablation resistance was attributed to a denser gradient oxide layer composed of central ZrO₂ layer, transitional ZrO₂-SiO₂ layer and marginal SiO₂ layer generated under the initial sticky net effect from SiCnw networks and subsequent oxide compensation from "Z-pins like" SiC rods.     

Palladium‐Catalyzed and Hybrid Acids‐Assisted Synthesis of [60]Fulleroazepines in One Pot under Mild Conditions: Annulation of N‐Sulfonyl‐2‐aminobiaryls with [60]Fullerene through Sequential C‐H Bond Activation,C‐C and C‐N Bond Formation

An extraordinarily efficient hybrid acids‐assisted, palladium‐catalyzed and chelating‐group‐assisted C H bond activation of N‐sulfonyl‐2‐aminobiaryls and their annulations with [60]fullerene via sequential C C and C N bond formation at room temperature to afford [60]fulleroazepines is demonstrated. The formation of [60]fulleroazepines is highly regioselective and tolerant to both electron‐withdrawing and electron‐donating groups on the aryl moiety and the reaction gives monofunctionalized fullerenes in good yields (up to 54% isolated yield and 92% based on converted C₆₀).     

Iridium‐Catalyzed Selective Synthesis of 4‐Substituted Benzofurans and Indoles via Directed Cyclodehydration

A directed cyclization‐dehydration cascade of α‐aryloxy ketones and α‐arylamino ketones was efficiently catalyzed by a cationic iridium‐BINAP complex, which afforded various types of 4‐substituted benzofurans and indoles in high yields with complete regioselectivity. The newly developed protocol also enabled the enantioselective preparation of chiral 4‐acetyloxindole using a chiral iridium catalyst.     

Discrete distribution of implanted and annealed arsenic atoms in silicon nanowires and its effect on device performance

We have theoretically investigated the effects of random discrete distribution of implanted and annealed arsenic (As) atoms on device characteristics of silicon nanowire (Si NW) transistors. Kinetic Monte Carlo simulation is used for generating realistic random distribution of active As atoms in Si NWs. The active As distributions obtained through the kinetic Monte Carlo simulation are introduced into the source and drain extensions of n-type gate-all-around NW transistors. The current–voltage characteristics are calculated using the non-equilibrium Green''s function method. The calculated results show significant fluctuation of the drain current. We examine the correlation between the drain current fluctuation and the factors related to random As distributions. We found that the fluctuation of the number of dopants in the source and drain extensions has little effect on the on-current fluctuation. We also found that the on-current fluctuation mainly originated from the randomness of interatomic distances of As atoms and hence is inherent in ultra-small NW transistors.     

Influence of preparation method and boron addition on the metal function properties of Ru?Sn catalysts for selective carbonyl hydrogenation

BACKGROUND: Improvements in the selective hydrogenation of unsaturated fatty acid methyl esters in order to obtain unsaturated fatty alcohols have been attempted through the preparation and modification of supported group VIII metallic catalysts. Suitable catalysts appear to be those based on supported Ru modified by Sn. The influence of preparation and activation methods on the structural and electronic properties of the metallic phase and the effect of modifications to these properties on the catalytic performance of Ru? Sn/Al₂O₃ catalysts was studied regarding selective hydrogenation of carbonyl groups. RESULTS: Preparation methods have a marked influence on the electronic state of Ru and its interaction with Sn. Temperature‐programmed reduction (TPR), Fourier transform infrared spectroscopy of chemisorbed CO (FTIR‐CO) and X‐ray photoelectron spectroscopy (XPS) results clearly show that the incorporation of sodium borohydride in the preparation leads to a greater Ru? Sn interaction when compared with catalysts prepared by co‐impregnation without B. The activation of catalysts without B (either by direct reduction or calcinations‐reduction) does not produce a strong Ru? Sn interaction. B‐containing catalysts exhibit higher hydrogenolytic and lower dehydrogenating activities. Selectivity towards oleyl alcohol formation was 37% for this catalyst, while catalysts without B were not suitable for obtaining fatty alcohols. CONCLUSION: The degree of interaction between Ru and Sn strongly depends on catalyst preparation and activation method where strong interaction promotes selectivity with respect to oleyl alcohol formation. On the contrary, catalysts with a weak Ru? Sn interaction do not show significant selectivity for the unsaturated alcohol. Copyright © 2010 Society of Chemical Industry     

Note on the use of profile features of Swapozhnikov's plastometric curves for assessment and blending of coking coals

In an effort to utilize the Sapozhnikov's plastometric test to evaluate Indian Coking coals, the authors have brought out, in two earlier publications, the significance of the profile features of the expansion pressure curves in supplementing the indices X and Y. A third parameter called profile length (L) has been found to be successful in the grading of Indian coking coals. In this Paper results are presented of studies made on a wide cross-section of Western and Australian coals. In view of the close interplay of dilatation, shrinkage and agglutination characteristics of coal on the quantity of coke the authors propose a unitary parameter called coking quotient involving the three indices in a rational manner. The coking quotient generally agrees with the other standard tests. A novel feature of this Paper is the development of a CQ-rank relationship by which blending of several coking coals can be optimized.     

The solubility of methane in aqueous solutions of monoethanolamine,diethanolamine and triethanolamine

The solubility of methane in 3 kmol/m³ solutions of monoethanolamine, diethanolamine, and triethanolamine was measured from 25° to 125°C and pressures up to about 13 MPa. Measurements were also made for the solubility of methane in water at 25° to 125°C and pressures up to 18 MPa in order to confirm the accuracy of the experimental technique. It is demonstrated that methane is more soluble (in terms of mole fraction) in the amine solution than in pure water. Furthermore, the solubility is an increasing function of the size of the alkanolamine. The solubility data were modeled using a Henry's-law approach and the results summarized in terms of salting-in coefficients.     

2-二乙硫基亚甲基-3-羰基(羟基)丁酸乙酯与吲哚及其衍生物的(脱硫)偶联反应

在回流条件下,二甲亚砜(DMSO)作溶剂,在20 mol％联萘酚酸存在下,2-二乙硫基亚甲基-3-羰基丁酸乙酯与吲哚及其衍生物能有效地进行脱硫偶联反应,高产率地生成β-吲哚基-β-乙硫基不饱和羰基化合物.在相同条件下,2-二乙硫基亚甲基-3-羟基丁酸乙酯与吲哚及其衍生物能有效地进行偶联反应,高产率地生成α-吲哚基二硫缩烯酮.该反应具有催化剂经济易得及其用量少、反应条件温和、环境友好和易操作等优点.