bluuebunny/crossref_metadata_2025 huggingface dataset:
Cleaner process for synthesis of zeolite MCM‐22 by vapor‐phase transport method
Authors: Liu Xingsheng , Li Yingxia , Chen Biaohua , Wang Ying
Published: July 2009

A cleaner process for synthesis of zeolite MCM‐22 by vapor‐phase transport method was studied in this paper. Firstly, zeolite MCM‐22 was synthesized at different hexamethyleneimine (HMI) dosages by vapor‐phase transport (VPT) method. It was concluded that the aluminosilicate gel was not crystallized completely and the product crystallinity was low when the HMI/gel mass ratio was <0.3. Then, the as‐synthesized product and the surplus liquid, which were obtained at mass ratio 0.3 HMI : 1.0 gel, were characterized by TG‐DTA and FTIR, respectively. It was found that a part of HMI did not play the role of structure‐directing and remained in the surplus liquid after synthesis of zeolite MCM‐22. The surplus liquid chemical properties, which have not change after synthesis of zeolite MCM‐22 by VPT method, still contained only HMI and H2O. Re‐adding of HMI and deionized water, the surplus liquid was reused to synthesize zeolite MCM‐22 by VPT method. Based on the experimental results of surplus liquid reuse, it was known that the surplus liquid can be reused via re‐adding of HMI and deionized water. It could make the VPT method become a cleaner process. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Synthesis and modification of zeolite NaA adsorbents for separation of hydrogen and methane
Authors: Liu Yanna , Xu Jingyang , Jin Lijun , Fang Yunming , Hu Haoquan
Published: July 2009

To improve the adsorption capacity of zeolite A, two kinds of zeolite NaA with submicron and hierarchical structure were prepared. The XRD patterns indicated that both synthesized products were pure zeolite with LTA‐type framework. The SEM images and laser particle size analysis showed that the particle size of submicron zeolite NaA was about 240 nm. The TEM and N2 adsorption/desorption isotherms proved the existence of mesopores in the hierarchical zeolite NaA. The adsorption capacities of single component CH4 or H2 on zeolite SrA adsorbents, obtained by Sr2+ ion‐exchange of submicron and hierarchical zeolite NaA, and commercial zeolite 5A adsorbent were measured by the static volume method at 25 °C and pressures up to 1 MPa. The results show that both prepared zeolite SrA adsorbents have higher adsorption capacities of CH4 and ideal separation factors of CH4/H2 than commercial zeolite 5A, and the submicron zeolite SrA has the largest adsorption capacity of CH4 and ideal separation factor of CH4/H2. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Nonlinear parametric predictive control. Application to a continuous stirred tank reactor
Authors: Assandri Armando , de Prada César , Cristea Smaranda , Martínez Ernesto
Published: July 2009

This paper presents a nonlinear model‐based controller based on the ideas of parametric predictive control applied to a continuous stirred tank reactor (CSTR) process unit. Controller design aims at avoiding the complexity of implementation and long computational times associated with conventional NMPC while maintaining the main advantage of taking into account process nonlinearities that are relevant for control. The design of the parametric predictive controller is based on a rather simplified process model having parameters that are instrumental in determining the required changes to the manipulated variables for error reduction. The nonlinear controller is easy to tune and can operate successfully over a wide range of operating conditions. The use of an estimator of unmeasured disturbances and process‐model mismatch further enhances the behavior of the controller. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Regular and inverted batch process structures for pressure swing distillation: a case study
Authors: Klein Andreas , Repke Jens‐Uwe
Published: July 2009

The main focus of this paper is on the comparison of the inverted and the regular pressure swing batch distillation processes for the separation of a homogenous azeotropic mixture. On the basis of a successful, experimentally validated rigorous model, a simulation study to identify the differences between the two processes and the influences of different structures on them is carried out. This identification of influences helps in finding out a heuristic base of the most suitable batch structure for a given separation problem. Especially the influence of the feed flow rate on the processes and the differences between the results on operation with different pressures will be addressed. Furthermore advantages, disadvantages and the limitations of both processes will be shown. In the end the best way of operating the pressure swing batch distillation will be presented depending on the product purity and the feed concentration for a given example. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Synthesis of 3‐methyl‐N‐substituted‐1H‐indole
Authors: Zhang Xiao‐Lin , Zhang Wei‐Hua , Yang Hong‐Xia Ou
Published: July 2009

A practical synthesis of 3‐methyl‐N‐substituted‐1H‐indole (N‐substituted‐skatole) starting from 2‐halogen phenylamine was described, by following acetylation or sulfonylation, alkylation and the intramolecular Heck reaction. In this article, effects of the reactions temperature, solvent, time, proportion and the mount of catalyst were investigated. Target product has an application prospect. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Influence of oil‐atomized air on flow and combustion characteristics in a 300 MWe down‐fired boiler
Authors: Li Zhengqi , Ren Feng , Chen Zhichao , Wang Jingjie , Chen Zhao , Zhang Juwei
Published: July 2009

A method of admitting oil‐atomized air into a furnace to adjust coal combustion in a down‐fired boiler is described. Experiments with a small‐scale furnace simulating a down‐fired, pulverized‐coal, 300‐MWe utility boiler were carried out at a single‐phase test facility to investigate the influence of oil‐atomized air on the aerodynamic field in the furnace. With the acceleration of oil by secondary air, the primary air/fuel can reach a more distant position with respect to the burner nozzle and the volume of the recirculation zone shrinks. Industrial experiments were also performed in a 300‐MWe full‐scale boiler. The gas temperature distribution along the primary air/fuel flow in the furnace and the gas components in the near‐wall region were measured with the dampers of the oil‐atomized air box open and closed. When open, the oil‐atomized air does not impede the ignition of the primary air/fuel and can carry the primary air/fuel to a position much deeper in the furnace, resulting in a lowered carbon content in the fly ash. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Human radiolabeled mass balance studies: objectives, utilities and limitations
Authors: Penner Natalia , Klunk Lewis J. , Prakash Chandra
Published: July 2009

The determination of metabolic pathways of a drug candidate through the identification of circulating and excreted metabolites is vitally important to understanding its physical and biological effects. Knowledge of metabolite profiles of a drug candidate in animals and humans is essential to ensure that animal species used in toxicological evaluations of new drug candidates are appropriate models of humans. The recent FDA final guidance recommends that human oxidative metabolites whose exposure exceeds 10% of the parent AUC at steady‐state should be assessed in at least one of the preclinical animal species used in toxicological assessment. Additional toxicological testing on metabolites that have higher exposure in humans than in preclinical species may be required. The metabolite profiles in laboratory animals and humans are generally accomplished by mass balance and excretion studies in which radiolabeled drugs are administered to these species. The biological fluids are collected, analysed for total radioactivity and evaluated for a quantitative profile of metabolites. Thus, these studies not only determine the rates and routes of excretion but also provide very critical information on the metabolic pathways of drugs in preclinical species and humans. In addition, these studies are required by regulatory agencies for the new drug approval process. Despite the usefulness of these radiolabeled mass balance studies, there is little concrete guidance on how to perform or assess these complex studies. This article examines the objectives, utilities and limitations of these studies and how these studies could be used for the determination of the metabolite exposure in animals and humans. Copyright © 2009 John Wiley & Sons, Ltd.
TpMRK regulates cell division of Tetrahymena in response to oxidative stress
Authors: Li Wenzhou , Zhang Siwei , Numata Osamu , Nozawa Yoshinori , Wang Shulin
Published: July 2009

TpMRK was identified as a stress‐responsive mitogen activated protein kinase (MAPK)‐related kinase and has been shown to play a critical role in the stress signalling in Tetrahymena cells. Here, we found that the mRNA expression of TpMRK was correlated with cell division of Tetrahymena with decreased expression occurring in cells prior to entering synchronous cell division induced by heat treatment. Notably, cell division was delayed with a lower division index of 40% after exposure to hydrogen peroxide while 85% of cells underwent cell division synchronously at 75 min after heat treatment without the oxidative exposure. Furthermore, inactivation of TpMRK signalling by p38 MAPK inhibitor SB203580 or MEK inhibitor PD 98059 partially derepressed cell division induced by hydrogen peroxide. Our data suggest that oxidative stimuli might cause aberration of synchronous cell division of Tetrahymena through activating the TpMRK cascade. Copyright © 2009 John Wiley & Sons, Ltd.
Numerical Study on Plate‐Fin Heat Exchangers with Plain Fins and Serrated Fins at Low Reynolds Number
Authors: Wang Y.‐Q. , Dong Q. W. , Liu M. S. , Wang D.
Published: July 2009

A simpler numerical model for plate‐fin heat exchangers with plain fins and serrated fins is presented, which incorporates the characteristics of fluid flow and heat transfer. The numerical simulations for heat exchangers with two fins at low Reynolds numbers are carried out by employing the simplified model and using the CFD code FLUENT. The results of heat transfer rate and pressure drop in numerical simulations are compared with the experimental results from the literature. It is shown that the results are in good agreement and the numerical model is reasonable and appropriate. The characteristics of fluid flow and heat transfer are analyzed and compared based on the numerical results. It is concluded that by applying the average heat transfer coefficient in practice, the heat transfer rate of the primary surface is overestimated, and the heat transfer rate and efficiency of the secondary surface are underestimated. The numerical modeling and conclusions provide the method and theoretical basis for the selection, optimization and analysis of plate‐fin heat exchangers.
On accurate and time efficient solution of primal‐mixed finite element equations in multiscale solid mechanics
Authors: Duff Iain , Mijuca Dubravka
Published: July 2009

In order to identify the best technique to solve a class of geometrically multiscale model problems in thermoelasticity, we examine a combination of a primal‐mixed finite element approach and direct sparse solvers and matrix scaling routines. The criteria for optimality are robustness, accuracy and execution time. It will be shown that the present finite element approach, where displacement and stress variables are simultaneously solved from large‐scale indefinite poorly scaled systems of equations using the sparse HSL solver MA57 with the aid of the matrix scaling routines MC64 or MC30 during the factorization process, enables a reliable solution even if hexahedral finite elements in a mesh differ in size up to six orders of magnitude. A number of tests in multiscale elasticity and thermoelasticity are examined to test the accuracy and execution time efficiency of the proposed solution approach on a standard PC computing platform. Copyright © 2009 John Wiley & Sons, Ltd.
Total Synthesis of (±)‐Physovenine
Authors: Kulkarni Mukund G. , Dhondge Attrimuni P. , Borhade Ajit S. , Gaikwad Dnyaneshwar D. , Chavhan Sanjay W. , Shaikh Yunnus B. , Nigdale Vijay B. , Desai Mayur P. , Birhade Deekshaputra R. , Shinde Mahadev P.
Published: July 2009

The Wittig olefination–Claisen rearrangement protocol was applied to the total synthesis of (±)‐physovenine. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A Facile and Efficient One‐Pot Synthesis of Substituted Quinolines from α‐Arylamino Ketones Under Vilsmeier Conditions
Authors: Wang Yan , Xin Xin , Liang Yongjiu , Lin Yingjie , Zhang Rui , Dong Dewen
Published: July 2009

An efficient one‐pot synthesis of substituted quinolines from α‐arylamino ketones in the presence of PBr3 in DMF has been developed. This general protocol provides a novel and facile access to substituted quinolines by sequential Vilsmeier–Haack reaction, intramolecular cyclization and aromatization reactions of α‐arylamino ketones. PBr3 plays a dual role in the quinoline synthesis: as a key component of the Vilsmeier reagent (PBr3/DMF) and as a reducing reagent. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Morphology and withanolide production of Withania coagulans hairy root cultures
Authors: Mirjalili Hossein M. , Fakhr‐Tabatabaei Seyyed M. , Bonfill Mercedes , Alizadeh Houshang , Cusido Rosa M. , Ghassempour Alireza , Palazon Javier
Published: July 2009

Inoculation of leaf sections of Withania coagulans with Agrobacterium tumefaciens strain C58C1 (pRiA4) induced transformed roots with the capacity to produce the most important bioactive compounds of Withania species, withanolide A and withaferin A. The hairy roots obtained showed two morphologies: callus‐like roots (CR) with a high capacity to produce withanolides and typical hairy roots (HR) with faster growth capacity and lower withanolide accumulation. The aux1 gene of pRiA4 was detected by PCR analyses in all roots showing callus‐like morphology. However, this gene was only detected in 12.5% of the roots showing typical hairy root morphology. This fact suggests a significant role of aux genes in the morphology of transformed roots. Time course studies of withanolide production showed that withanolide A accumulated during the first part of the culture whereas the maximum accumulation of withaferin A occurred at the end of the culture period. Some transformed root lines, such as HR112 and CR26, showed considerable potential to produce withanolides in a scaled up bioreactor system, especially the important pharmaceutical compound withanolide A.
Elicitation of secondary metabolism in Echinacea purpurea L. by gibberellic acid and triazoles
Authors: Jones A. Maxwell P. , Saxena Praveen K. , Murch Susan J.
Published: July 2009

In vitro bioreactor production of Echinacea purpurea L. was used to facilitate the screening of compounds capable of eliciting increased secondary metabolite production. Based on previous experience with various bioreactors, the Southern Sun Liquid Lab Rocker was selected for this study as it produces healthy, vigorous, whole plants. The focus of the present study was to quantify the concentration of the medicinally important secondary metabolites caftaric acid and cichoric acid and to study the effect of growth regulators on the production of these compounds in this system. Both marker compounds were produced at levels that compared favorably to field grown plants. Application of gibberellic acid (GA3), paclobutrazol, uniconazole and a combined treatment of GA3 with paclobutrazol to the in vitro plants generally increased the concentration of caftaric acid in the roots with little effect on the concentration in the shoots. The concentration of cichoric acid was higher in the roots of treated plants than in the roots of control plants, but lower in corresponding shoots. The present study highlights the use of in vitro production of whole plants as a model system for studying the regulation of plant secondary metabolism in a controlled environment.
Effect of initial ammonium concentration on taxoid production and biosynthesis genes expression profile in suspension cultures of Taxus chinensis cells
Authors: Zhou Xin , Zhong Jian‐Jiang
Published: July 2009

The effect of initial ammonium concentration in medium on production of taxuyunnanine C (Tc) in suspension cultures of Taxus chinensis was investigated. The results showed that the cell growth was reduced at an initial ammonium concentration of 2 mM when compared to the control (20 mM of initial ammonium in medium), but interestingly the Tc content was enhanced by two fold to 8.07 mg/g DW. The transcription of a couple of key genes in taxoid biosynthetic pathway was investigated by quantitative real‐time PCR to understand why Tc biosynthesis was improved at the low initial medium ammonium (2 mM). It was found that the transcription level of genes of geranylgeranyl diphosphate synthase, taxadiene synthase, taxadiene 5α‐hydroxylase, taxadiene 5α‐ol O‐acetyltransferase, taxane 10β‐hydroxylase and taxadiene 13α‐hydroxylase were all induced in the early stage of cultivation at 2 mM of initial ammonium compared to the control (20 mM of initial ammonium). The stimulation of secondary metabolite synthesis by a lower ammonium concentration may be resulted from the ammonium deficiency‐induced transcription of Tc biosynthetic genes.
Oxidative stress induces alkaloid production in Uncaria tomentosa root and cell cultures in bioreactors
Authors: Huerta‐Heredia Ariana A. , Marín‐López Ricardo , Ponce‐Noyola Teresa , Cerda‐García‐Rojas Carlos M. , Trejo‐Tapia Gabriela , Ramos‐Valdivia Ana C.
Published: July 2009

The effect of oxidative stress on indole alkaloids accumulation by cell suspensions and root cultures of Uncaria tomentosa in bioreactors was investigated. Hydrogen peroxide (H2O2, 200 μM) added to U. tomentosa cell suspension cultures in shaken flasks induced the production of monoterpenoid oxindole alkaloids (MOA) up to 40.0 μg/L. In a stirred tank bioreactor, MOA were enhanced by exogenous H2O2 (200 μM) from no detection up to 59.3 μg/L. Root cultures grew linearly in shaken flasks with a μ=0.045 days−1 and maximum biomass of 12.08±1.24 g DW/L (at day 30). Roots accumulated 3α‐dihydrocadambine (DHC) 2354.3±244.8 μg/g DW (at day 40) and MOA 348.2±32.1 μg/g DW (at day 18). Exogenous addition of H2O2 had a differential effect on DHC and MOA production in shaken flasks. At 200 μM H2O2, MOA were enhanced by 56% and DHC by 30%; while addition of 800 and 1000 μM H2O2, reduced by 30–40% DHC accumulation without change in MOA. Root cultures in the airlift reactor produced extracellular H2O2 with a characteristic biphasic profile after changing aeration. Maximum MOA was 9.06 mg/L at day 60 while at this time roots reached ca. 1 mg/L of DHC. Intracellular H2O2 in root cultures growing in the bioreactor was 0.87 μmol/g DW compared to 0.26 μmol/g DW of shaken flasks cultures. These results were in agreement with a higher activity of the antioxidant enzymes superoxide dismutase and peroxidase by 6‐ and 2‐times, respectively. U. tomentosa roots growing in the airlift bioreactor were exposed to an oxidative stress and their antioxidant system was active allowing them to produce oxindole alkaloids.
On the impact of anisotropic mesh adaptation on computational wind engineering
Authors: Aubé Martin S. , Habashi Wagdi G. , Wang Hongzhi , Torok Dennis
Published: July 2009

This paper addresses the critical issue of the accuracy of CFD predictions for wind engineering. Flows around the Silsoe Cube, a high‐rise building (the Jin Mao Tower), and a low‐rise large‐span building (the Pudong International Airport) are computed with the Navier–Stokes solver FENSAP and compared with measurements. Computations are carried out for two wind directions, by solving the steady‐state ensemble‐averaged Navier–Stokes equations with the Spalart–Allmaras one‐equation turbulence model. Pressure coefficients compare well with wind tunnel experiments and the accuracy of the flow solutions is further improved via an automatic mesh adaptation that dynamically places grid points where the flow physics require them, while keeping the number of unknowns and solution time substantially at the same level. Copyright © 2009 John Wiley & Sons, Ltd.
Long‐term cell‐mediated protein release from calcium phosphate ceramics
Authors: Wernike Ellen , Hofstetter Willy , Liu Yuelian , Wu Gang , Sebald Hans‐Jörg , Wismeijer Daniel , Hunziker Ernst B. , Siebenrock Klaus‐Arno , Klenke Frank M.
Published: July 2009

Efficient delivery of growth factors from carrier biomaterials depends critically on the release kinetics of the proteins that constitute the carrier. Immobilizing growth factors to calcium phosphate ceramics has been attempted by direct adsorption and usually resulted in a rapid and passive release of the superficially adherent proteins. The insufficient retention of growth factors limited their bioavailability and their efficacy in the treatment of bone regeneration. In this study, a coprecipitation technique of proteins and calcium phosphate was employed to modify the delivery of proteins from biphasic calcium phosphate (BCP) ceramics. To this end, tritium‐labeled bovine serum albumin ([3H]BSA) was utilized as a model protein to analyze the coprecipitation efficacy and the release kinetics of the protein from the carrier material. Conventional adsorption of [3H]BSA resulted in a rapid and passive release of the protein from BCP ceramics, whereas the coprecipitation technique effectively prevented the burst release of [3H]BSA. Further analysis of the in vitro kinetics demonstrated a sustained, cell‐mediated release of coprecipitated [3H]BSA from BCP ceramics induced by resorbing osteoclasts. The coprecipitation technique described herein, achieved a physiologic‐like protein release, by incorporating [3H]BSA into its respective carriers, rendering it a promising tool in growth factor delivery for bone healing. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Preparation, quality control and stability of 99mTc‐sparafloxacin complex, a novel agent for detecting sites of infection
Authors: Motaleb M. A.
Published: July 2009

Labeling of sparafloxacin with technetium‐99m using stannous chloride as a reducing agent was investigated. Dependence of the yield of 99mTc‐sparafloxacin complex on the concentration of sparafloxacin, reducing agent, pH and reaction time was studied. Under optimum conditions, the labeling yield of 99mTc‐sparafloxacin complex (95%) was achieved by using 2.5 mg of sparafloxacin, 50 µg of Sn(II), pH 10 and 30‐min reaction time. 99mTc‐sparafloxacin complex was stable for 3 h after labeling, then the yield decreased gradually to 81.9% at 6 h. Biodistribution studies in rats were carried out in experimentally induced infection in the left thigh using Staphylococcus aureus. The ratios of bacterial infected thigh/contralateral thigh were then evaluated. The time for the maximum accumulation of 99mTc‐sparafloxacin at the site of the infection was 30 min after the administration followed by gradual decline. The abscess‐to‐muscle ratio for 99mTc‐sparafloxacin was 5.9±0.7, while that for the commercially available 99mTc‐ciprofloxacin was 3.8±0.5 under the same experimental paradigm, indicating that 99mTc‐sparafloxacin could be used for infection imaging. Copyright © 2009 John Wiley & Sons, Ltd.
Binding kinetics and activity of human poly(ADP‐ribose) polymerase‐1 on oligo‐deoxyribonucleotide substrates
Authors: Jorgensen Timothy J. , Chen Kevin , Chasovskikh Sergey , Roy Rabindra , Dritschilo Anatoly , Üren Aykut
Published: July 2009

Poly(ADP‐ribose) polymerase‐1 (PARP‐1) is a mammalian enzyme that attaches long branching chains of ADP‐ribose to specific nuclear proteins, including itself. Because its activity in vitro is dependent upon interaction with broken DNA, it has been postulated that PARP‐1 plays an important role in DNA strand‐break repair in vivo. The exact mechanism of binding to DNA and the structural determinants of binding remain to be defined, but regions of transition from single‐stranded to double‐strandedness may be important recognition sites. Here we employ surface plasmon resonance (SPR) to investigate this hypothesis. Oligodeoxynucleotide (ODN) substrates that mimic DNA with different degrees of single‐strandedness were used for measurements of both PARP‐1/DNA binding kinetics and PARP‐1's enzyme activities. We found that binding correlated with activity, but was unrelated to single‐strandedness of the ODN. Instead, PARP‐1 binding and activity were highest on ODNs that modeled a DNA double‐strand break (DSB). These results provide support for PARP‐1 recognizing and binding DSBs in a manner that is independent of single‐stranded features, and demonstrate the usefulness of SPR for simultaneously investigating both PARP‐1 binding and PARP‐1 auto‐poly(ADP‐ribosyl)ation activities within the same in vitro system. Copyright © 2009 John Wiley & Sons, Ltd.
Use of drought indices in climate change impact assessment studies: an application to Greece
Authors: Mavromatis T.
Published: July 2009

This paper presents a framework for making use of drought indices in climate change impact assessment studies. To achieve this goal: (1) linear relationships between drought indices and satellite soil moisture information, derived from the ERS scatterometer [Soil Water Index, (SWI)] for the years 1992–2000, are developed by employing [analysis of covariance (ANCOVA)] and (2) the vulnerability of soil water content to climate change is assessed using regional climate model (RCM) projections. Several drought indices are evaluated for their abilities to monitor SWI, on a monthly basis, at nine locations in Greece. The original Palmer Drought Severity Index (Orig‐PDSI) and its self‐calibrated version (SC‐PDSI) correlated best with SWI in three stations each and precipitation in two. The degree of agreement, however, varies substantially among the sites. Seasonality has a significant effect on the relationship between the SWI and the two aforementioned drought indices (Orig‐PDSI, SC‐PDSI), presenting a bimodal pattern that fluctuates markedly during the year. ANCOVA has proved to be a useful method for measuring the agreement between SWI and the drought indices (r2 ranged from 46.2% to 79.9%), implying that drought indices can be an important information source for detecting and monitoring drought. 11 different RCM runs are compared for their abilities to reproduce present climate mean and variability of temperature and precipitation. Orig‐PDSI is not sensitive to the much warmer future climate change scenarios constructed and, therefore, is not suggested for climate change impacts assessment studies. SC‐PDSI, on the other hand, has the potential to be used; however, its responses depend on the time period on which the climate characteristics and duration factors are computed from. Copyright © 2009 Royal Meteorological Society
Microchip free flow planar reversed phase electrochromatography with monolithic stationary phase
Authors: Wang Pingli , Tao Dingyin , Zhang Lihua , Liang Zhen , Zhang Yukui
Published: July 2009

In this study, microchip free flow planar RP electrochromatography (μFF‐PRPEC) was developed by in situ polymerization of monolithic materials in microchamber, and successfully applied for the separation of dyes and proteins. Poly(butyle methyacrylate‐co‐ethylene dimethacrylate) was prepared by UV‐initiated polymerization in a glass microchamber (42 mm long, 23 mm wide, and 28 μm deep). A mixture of 1‐propanol, 1,4‐butanediol, and water was chosen as porogens, and 1.2% (wt%) 2‐acrylamide‐2‐methyl‐propanesulfonic acid (AMPS) was added into the polymerization solution to generate EOF. With 30% v/v ACN‐15 mM Tris‐HCl as the mobile phase, rhodamine B and methyl green were separated from each other with 400 V transverse voltage applied, and resolution as high as 4.6 was obtained, much higher than that obtained by μFFE under optimal conditions. Furthermore, μFF‐PRPEC was also successfully applied into the separation of lysozyme and ribonuclease B, and resolution as high as 9.4 was obtained. All these results demonstrate that μFF‐RPPEC might have great potential in the microscale continuous preparation of samples with improved resolution compared to μFFE.
New Types of Fluorescent Polymers with Bis‐Silicon‐Bridged p‐Terphenyl as a Building Unit
Authors: Li Liangchun , Xu Caihong , Li Shuhong
Published: July 2009

A series of novel polymers containing a bis‐silicon‐bridged p‐terphenyl skeleton in the main chain is synthesized using hydrosilylation reactions with 6,12‐dihydro‐6,12‐dimethyl‐6,12‐disilaindeno[1,2‐b]fluorene (2) as the key monomer. Their photophysical and thermal properties are investigated and compared with those of the related monomer and model compounds. All polymers show an improved thermal stability with respect to the small molecules. In dilute solutions, the polymers constructed with alternate bis‐silicon‐bridged p‐terphenyl and saturated unit show constant emission maximum wavelengths and fluorescence quantum yields, comparable to those of monomer 2, while the polymer having an unsaturated linkage between the bis‐silicon‐bridged p‐terphenyl units exhibits a low fluorescence quantum yield with a red‐shifted emission maximum wavelength.

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The similar days method for predicting near surface wind vectors
Authors: Klausner Ziv , Kaplan Hadassah , Fattal Eyal
Published: July 2009

A reliable forecast of the wind vector at a given site is an important problem with a broad scope of application. Many uses are in the field of wind power in which prediction of strong winds is important; other uses are in the field of civil engineering, where wind gusts are important to structural integrity. For predicting air pollution events or the hazard zone in case of toxic gas accidents the low wind scenarios are of the highest importance, especially under stable conditions. These low wind scenarios are the situations which meso‐scale numerical models encounter difficulties or are often neglected when dealing with wind power tasks. Additional drawbacks of meso‐scale numerical models in this context are their lack of site‐specific detail and the fact that they are very demanding numerically.

The ‘similar days’ method presented here is a method for the prediction of winds at a given location which works well also for low and variable wind conditions. The method is very efficient numerically: typically, runtime is less than a minute on a single PC. This method is based on using the last few hours' measurements at the given site and comparing it to an historical database. A set of criteria is defined to determine the time series similarity. Those similar days are used to construct the forecast.

The similar days method was applied to a total of 5 years of measurements collected in two different locations. Very good agreement was achieved between prediction and measurements. Copyright © 2009 Royal Meteorological Society
Frequent PIK3CA gene amplification and its clinical significance in colorectal cancer
Authors: Jehan Zeenath , Bavi Prashant , Sultana Mehar , Abubaker Jehad , Bu Rong , Hussain Azhar , Alsbeih Ghazi , Al‐Sanea Nasser , Abduljabbar Alaa , Ashari Luai H , Alhomoud Samar , Al‐Dayel Fouad , Uddin Shahab , Al‐Kuraya Khawla S
Published: July 2009

Using a DNA microarray approach to screen for gene copy number changes in 20 colorectal (CR) carcinoma samples and filtering for high‐level DNA copy number changes, we detected an amplicon at 3q26 containing the PIK3CA gene. Fluorescence in situ hybridization was employed for evaluation of PIK3CA amplification on a progression CR tissue microarray containing 448 CR carcinomas, normal mucosa, and adenomas with follow‐up information. PIK3CA amplification (ratio PIK3CA/centromere 3≥2.0) was found in 38% of cancers, while another 19% of tumours had PIK3CA gains (ratio >1.0 but <2.0). Both PIK3CA amplification and gains were associated with high levels of PIK3CA protein expression and no association was seen between PIK3CA amplification and PIK3CA mutation. In a subset of 220 patients who received adjuvant chemotherapy and/or radiotherapy, survival in patients with PIK3CA‐amplified cancers was significantly longer compared with patients with cancers without amplification. This association was independent of stage, grade, histology subtype, gender, and age categories. Interestingly, PIK3CA amplification was also seen in CR adenomas, indicating an early genetic alteration, and was also a frequent event in colorectal carcinogenesis. Furthermore, PIK3CA amplification is an independent prognostic marker for better survival and may be one of the promising markers to define CRC subsets that may maximally benefit from adjuvant therapy. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Studies on the effects of oral administration of nutrient mixture, quercetin and red onions on the bioavailability of epigallocatechin gallate from green tea extract
Authors: Kale Anup , Gawande Sonia , Kotwal Swati , Netke Shrirang , Roomi Waheed , Ivanov Vadim , Niedzwiecki Aleksandra , Rath Matthias
Published: July 2009

Epigallocatechin gallate (EGCG), a main anticancer component in green tea, has a poor bioavailability in rats and humans due to oxidation, metabolism and its efflux. It was hypothesized that nutrients that address these problems might result in increased bioavailability. Plasma concentrations of EGCG at various time intervals were determined to calculate and compare the pharmacokinetic parameters after oral administration of green tea extract (GTE) or GTE as a nutrient mixture (E) or E + quercetin (Q)/red onions. In rat studies, supplementation of GTE with other nutrients (E) or E + Q raised the plasma Cmax from 55.29 ± 1.70 to 61.94 ± 1.70 ng/mL and 94.44 ± 1.59 ng/mL, respectively. The corresponding t½ elimination was 2.04 ± 0.2 h, 3.63 ± 0.66 h and 2.28 ± 0.049 h. The AUC0–24h were 510.16 ± 9.88 for GTE, 601.72 ± 19.10 ng.h/mL for E and 794.08 ± 15.27 ng.h/mL (p ≤ 0.05) for E + Q. In human studies when GTE was fed as GTE or E or E + red onions, the Cmax values were 348.4 ± 76.6, 384.0 ± 78.5 ng/mL and 468.4 ± 131.4. AUC0–8h was 1784.1 ± 56.06 (GTE), 1971.5 ± 566.5 ng.h/mL (E) and 2490 ± 878.1 (E + Q), but the change in t½ elimination was not significant.

In conclusion, it is possible to increase the bioavailability of EGCG by supplementing it with nutrients and quercetin. Copyright © 2009 John Wiley & Sons, Ltd.
Spearmint herbal tea has significant anti‐androgen effects in polycystic ovarian syndrome. a randomized controlled trial
Authors: Grant Paul
Published: July 2009

Hirsutism in polycystic ovarian syndrome (PCOS), consequent to elevated androgen levels leads to significant cosmetic and psychological problems. Recent research in Turkey has shown that spearmint tea has antiandrogenic properties in females with hirsutism. No research has yet been undertaken to assess whether a reduction in androgen levels brought about by spearmint tea, translates to a clinical improvement in the degree of hirsutism.

This study was a two centre, 30 day randomized controlled trial. Forty two volunteers were randomized to take spearmint tea twice a day for a 1 month period and compared with a placebo herbal tea. At 0, 15 and 30 days of the study serum androgen hormone levels and gonadotrophins were checked, the degree of hirsutism was clinically rated using the Ferriman‐Galwey score and a questionnaire (the modified DQLI = Dermatology Quality of Life Index) was used to assess improvements in the level of self‐reported hirsutism.

Forty one of 42 patients completed the study. Free and total testosterone levels were significantly reduced over the 30 day period in the spearmint tea group (p < 0.05). LH and FSH also increased (p < 0.05). Patient's subjective assessments of their degree of hirsutism scored by the modified DQLI were significantly reduced in the spearmint tea group (p < 0.05). There was, however, no significant reduction in the objective Ferriman‐Galwey ratings of hirsutism between the two trial groups over the trial duration (p = 0.12). There was a clear and significant alteration in the relevant hormone levels. This is associated clinically with a reduction in the self‐reported degree of hirsutism but unfortunately not with the objectively rated score.

It was demonstrated and confirmed that spearmint has antiandrogen properties, the simple fact that this does not clearly translate into clinical practice is due to the relationship between androgen hormones and follicular hair growth and cell turnover time. Simply put, the study duration was not long enough. The original studies from Turkey were in fact only 5 days long. The time taken for hirsutism to resolve is significant and a much longer future study is proposed as the preliminary findings are encouraging that spearmint has the potential for use as a helpful and natural treatment for hirsutism in PCOS. Copyright © 2009 John Wiley & Sons, Ltd.
Inhibitory effect of tea polyphenols on local tissue damage induced by snake venoms
Authors: Pithayanukul P. , Leanpolchareanchai J. , Bavovada R.
Published: July 2009

The methanolic extract of fresh tea leaves of Camellia sinensis L. (Theaceae) (CS) was assayed for its potential to inhibit enzymes with hydrolytic activity in Naja naja kaouthia Lesson (Elapidae) and Calloselasma rhodostoma Kuhl (Viperidae) venoms. These snake venom enzymes are responsible for the early effects of envenomation, such as local tissue damage and inflammation. The CS extract inhibited phospholipase A2, proteases, hyaluronidase and l‐amino acid oxidase in both venoms by in vitro neutralization and inhibited the hemorrhagic and the dermonecrotic activities of the venoms in vivo. It is suggested that the inhibitory potential of the CS extract against local tissue damage induced by snake venoms may be attributed to complexation and chelation between the venom proteins and the phenolic contents of the extract. Copyright © 2009 John Wiley & Sons, Ltd.
Hesperidin suppresses adjuvant arthritis in rats by inhibiting synoviocyte activity
Authors: Li Rong , Cai Li , Xie Xue‐feng , Yang Feng , Li Jun
Published: July 2009

The present study was designed to investigate the effect of hesperidin on rat adjuvant arthritis (AA) and to elucidate the involvement of synoviocytes in this process. Freund's complete adjuvant was used to induce AA in rats. Secondary paw swelling and the index of immune organs of AA rats were measured. Macrophage‐like synoviocytes were separated by the method of collagenase and trypsin digestion. Synoviocyte proliferation was assayed by MTT assay. TNF‐α, IL‐1β and IL‐10 production of synoviocytes were examined with ELISA. The levels of TNF‐α, IL‐1β, IL‐10 mRNA were determined using RT‐PCR. It was found that intragastric hesperidin administration (80, 160 mg/kg) significantly inhibited secondary paw swelling and restored the index of immune organs of AA rats. Furthermore, synoviocyte proliferation in AA rats was apparently suppressed after hesperidin treatment, which was accompanied by decreased transcription as well as production of TNF‐α and IL‐1β from synoviocytes. Hesperidin also markedly increased IL‐10 at both protein and transcription levels in AA rats. In aggregate, the above results demonstrate that hesperidin has a therapeutic effect on AA and the mechanisms are partly related to inhibiting synoviocyte activity and modulating inflammatory cytokine production of synoviocytes which play a crucial role in the pathogenesis of AA. Copyright © 2009 John Wiley & Sons, Ltd.
Eviprostat suppresses urinary oxidative stress in a rabbit model of partial bladder outlet obstruction and in patients with benign prostatic hyperplasia
Authors: Matsumoto Seiji , Hanai Tadashi , Matsui Takahiro , Oka Michiko , Tanaka Mitsushi , Uemura Hirotsugu
Published: July 2009

Eviprostat is a phytotherapeutic agent that has been used widely for more than 40 years in the treatment of benign prostatic hyperplasia (BPH) in Japan and Germany, and is known to have antioxidant activity. The present study investigated the effect of Eviprostat on the levels of the urinary oxidative stress marker 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) in a rabbit model of surgical partial bladder outlet obstruction (PBOO) and in patients with lower urinary tract symptoms (LUTS) associated with BPH. In the rabbit model, 8‐OHdG levels in urine collected after 3 weeks of PBOO were 3.8‐fold higher than in the urine of sham‐operated rabbits. When twice‐daily Eviprostat was administered orally throughout the 3‐week PBOO period, the increase in urinary 8‐OHdG levels was suppressed by 70%. In the clinical study, nine patients who received Eviprostat for 4 weeks showed 2.5‐fold lower urinary 8‐OHdG levels than before treatment. During Eviprostat treatment, the total International Prostate Symptom Score (IPSS) decreased from 16.56 ± 2.74 to 13.67 ± 2.30 and the quality of life score from 4.22 ± 0.40 to 3.22 ± 0.46. The findings provide evidence that the antioxidant activity of Eviprostat is responsible for its beneficial effects in the treatment of BPH. Copyright © 2009 John Wiley & Sons, Ltd.
Bile acid‐binding activity of young persimmon (Diospyros kaki) fruit and its hypolipidemic effect in mice
Authors: Matsumoto Kenji , Yokoyama Shin‐ichiro , Gato Nobuki
Published: July 2009

The hypolipidemic effects and bile acid‐binding properties of young persimmon (Diospyros kaki) fruit were examined. In an animal experiment, male C57BL/6.Cr mice (n = 5) were fed an AIN‐76‐modified high fat diet supplemented with 2% or 5% (w/w) dried young persimmon fruit (YP) for 10 weeks. The intake of YP significantly enhanced fecal bile acid excretion and lowered the concentration of hepatic lipids and plasma cholesterol. Analysis of gene expression in liver tissue showed that 2% or 5% YP up‐regulated the expression of the sterol regulatory element‐binding protein‐2 gene. In the 5% group, there were increased expressions of the genes for cholesterol 7α‐hydroxylase and the low‐density lipoprotein receptor. Next, the bile acid‐binding ability of YP was analysed in vitro using cholic acid (CA). In 100–2000 µM CA solutions, 1% (w/v) YP adsorbed approximately 60% of CA, while dried mature persimmon fruit adsorbed approximately 20% of CA. The positive control, cholestyramine, adsorbed approximately 80% of CA in the 100–2000 µM CA solutions. A crude tannin extract from YP, which contained 54.7% condensed tannins, adsorbed approximately 78% of CA in the 2000 µM CA solutions. These results suggest that the ability of YP to bind bile acid contributes to its hypolipidemic effect in mice. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of sinomenine on the in vitro intestinal epithelial transport of selected compounds
Authors: Lu Zhilei , Chen Weiyang , Viljoen Alvaro , Hamman Josias H.
Published: July 2009

Herbal products can interfere with allopathic medicinal treatment through pharmacokinetic and pharmacodynamic interactions. Although pharmacokinetic interactions that alter drug absorption may cause variable and unsatisfactory drug bioavailability, a drug absorption enhancement effect of a herb may be used to ensure sufficient absorption of poorly absorbable drugs. The effect of the hydrochloride salt of sinomenine, an alkaloid obtained from the plant Sinomenium acutum, on the transepithelial electrical resistance and transport of different compounds (including cimetidine, vitamin C, rutin, luteolin and insulin) across Caco‐2 epithelial cell monolayers was investigated in this study. Sinomenine HCl induced a concentration dependent lowering effect on the transepithelial electrical resistance of Caco‐2 cell monolayers, which was completely reversible. Sinomenine HCl significantly increased the transport of all the test compounds in the apical‐to‐basolateral direction compared with the control group and decreased the transport of cimetidine, a P‐glycoprotein substrate, in the basolateral‐to‐apical direction. From these results it can be concluded that sinomenine HCl increases drug absorption across the intestinal epithelium by means of one or more mechanisms including a transient opening of the tight junctions (as indicated by a reduction in transepithelial electrical resistance) to allow for paracellular transport and/or inhibition of active drug efflux transport (as indicated by inhibition of basolateral‐to‐apical transport of cimetidine). Copyright © 2009 John Wiley & Sons, Ltd.
Cytotoxic guaianolide from Anthemis segetalis (Asteraceae)
Authors: Vučković Ivan , Vujisić Ljubodrag , Stešević Danijela , Radulović Siniša , Lazić Milan , Milosavljević Slobodan
Published: July 2009

Two epimeric guaianolides were isolated from the aerial parts of Anthemis segetalis. These compounds have not been detected in any Anthemis species so far. One of them was tested for cytotoxicity against human cervical cancer (HeLa) and murine melanoma (B16) cell lines showing appreciable activity. Copyright © 2009 John Wiley & Sons, Ltd.
Hypoglycemic effect of aqueous extract of seabuckthorn (Hippophae rhamnoides L.) seed residues in streptozotocin‐induced diabetic rats
Authors: Zhang Wen , Zhao Jingjing , Wang Jiesi , Pang Xiufeng , Zhuang Xiuyuan , Zhu Xinglei , Qu Weijing
Published: July 2009

An extract of seabuckthorn (Hippophae rhamnoides L.) seed residues has been shown to possess hypoglycemic and hypolipidemic properties in normal mice. The present study investigated the effects of an aqueous extract of seabuckthorn seed residues (ASSR) on serum glucose, lipid profiles and antioxidant parameters in streptozotocin‐induced diabetic rats. Male Sprague‐Dawley rats were divided into four groups: a normal control group; diabetic control group; diabetic groups supplemented with 5 mg/kg body weight glibenclamide (reference drug) and 400 mg/kg body weight ASSR. Diabetes in rats was induced by intraperitoneal injection of streptozotocin (45 mg/kg body weight). Vehicle (distilled water), glibenclamide and ASSR were administered orally to normal and diabetic rats once a day lasting for 4 weeks. The data showed that administration of ASSR significantly lowered the serum glucose, triglyceride and nitric oxide levels in diabetic rats. Moreover, ASSR treatment also increased serum superoxide dismutase activity and glutathione level markedly. These results show that ASSR has hypoglycemic, hypotriglyceridemic and antioxidant effects in streptozotocin‐induced diabetic rats, suggesting that ASSR supplementation can be useful in preventing diabetic complications associated with hyperlipidemia and oxidative stress. Copyright © 2009 John Wiley & Sons, Ltd.
Hypericum perforatum L. (St John's wort) extract Ze 117 inhibits dopamine re‐uptake in rat striatal brain slices. An implication for use in smoking cessation treatment?
Authors: Ruedeberg C. , Wiesmann U. N. , Brattstroem A. , Honegger U. E.
Published: July 2009

Classic synthetic antidepressant drugs, as well as St John's wort extract (SJW), directly inhibit the re‐uptake of norepinephrine (NE) and/or serotonin (5‐HT) into pre‐synaptic axons. With chronic treatment they induce adaptive changes in a number of neurotransmitter receptors in synaptic membranes. The immediate effects of SJW Ze 117, an extract low in hyperforin content, on the specific dopamine (DA) uptake were studied in rat striatal brain slices and compared with the effects on NE and 5‐HT uptake in rat cortical brain slices.

Specific DA uptake was inhibited in a dose dependent manner. In contrast to the findings in synaptosomal preparations published so far, the extract showed different inhibitory potencies for the respective transporters. The potencies for the uptake inhibition of NA, DA and 5‐HT were 30, 7 and 1, respectively. The results indicate that the SJW Ze 117 extract interferes in three ways with the individual uptakes of the relevant neurotransmitters that are considered to be causal in the development of depression.

This observation, the concomitant and potent inhibition of DA re‐uptake by SJW extract, may additionally provide a rationale for the treatment of nicotine or drug addiction with SJW. Copyright © 2009 John Wiley & Sons, Ltd.