bluuebunny/crossref_metadata_2025 huggingface dataset:
Shape optimization of the initial blank in the sheet metal forming process using equivalent static loads
Authors: Lee Jae‐Jun , Park Gyung‐Jin
Published: July 2010

In the sheet metal forming process, forming the final desired shape is difficult to obtain due to wrinkling, tearing, failure of material, etc. Various conditions of the forming process should be controlled for the desired shape. These conditions are the velocity of the punch, the friction factor, the blank holding force, the initial shape of the blank and others. Many researchers have conducted studies to predetermine the initial blank shape. The structural optimization technique is one of them. Non‐linear response structural optimization is required because non‐linearities are involved in the analysis of the metal forming process. When the conventional method is utilized, the cost is extremely high due to repeated non‐linear analysis for function and sensitivity calculation. In this paper, the equivalent static loads (ESLs) method is used to determine the blank shape which leads to the final desired shape and reduced wrinkling. The ESLs method is a structural optimization method where non‐linear dynamic loads are transformed into ESLs, and these ESLs are utilized as external loads in linear response optimization. The design is updated in linear response optimization. Non‐linear analysis is performed with the updated design and the process proceeds in a cyclic manner. An optimization formulation is defined for the examples, the formulated problems are solved to verify the proposed method and the results are discussed. Non‐linear analysis is performed using the commercial software LS‐DYNA, NASTRAN is used for calculating the ESLs and linear response optimization, and an interface program for LS‐DYNA and NASTRAN is developed. Copyright © 2010 John Wiley & Sons, Ltd.
A comparison of wave‐based discontinuous Galerkin, ultra‐weak and least‐square methods for wave problems
Authors: Gabard G. , Gamallo P. , Huttunen T.
Published: July 2010

Several numerical methods using non‐polynomial interpolation have been proposed for wave propagation problems at high frequencies. The common feature of these methods is that in each element, the solution is approximated by a set of local solutions. They can provide very accurate solutions with a much smaller number of degrees of freedom compared to polynomial interpolation. There are however significant differences in the way the matching conditions enforcing the continuity of the solution between elements can be formulated. The similarities and discrepancies between several non‐polynomial numerical methods are discussed in the context of the Helmholtz equation. The present comparison is concerned with the ultra‐weak variational formulation (UWVF), the least‐squares method (LSM) and the discontinuous Galerkin method with numerical flux (DGM). An analysis in terms of Trefftz methods provides an interesting insight into the properties of these methods. Second, the UWVF and the LSM are reformulated in a similar fashion to that of the DGM. This offers a unified framework to understand the properties of several non‐polynomial methods. Numerical results are also presented to put in perspective the relative accuracy of the methods. The numerical accuracies of the methods are compared with the interpolation errors of the wave bases. Copyright © 2010 John Wiley & Sons, Ltd.
Evaluating the effects of automobile safety regulation
Authors: Graham John D. , Garber Steven
Published: July 2010

Automobile safety standards adopted because of federal legislation have, according to many researchers, failed to save lives; safer cars, they infer, induce more dangerous driving. Results from the major study suggesting this conclusion are shown, however, to be quite sensitive to reasonable changes in the empirical model. An alternative statistical analysis of death rates supports a very different conclusion: Safety standards have saved tens of thousands of lives during the 1970s. More broadly, the article illustrates some general pitfalls in using statistical results in policy analysis, and how they can be avoided.
The price of local discretion: Inequalities in welfare spending within texas
Authors: Grubb W. Norton
Published: July 2010

Discretion at the local level in the administration of state or federal programs may generate inequalities in spending among the different localities within a state. Among the counties of Texas, inequalities in welfare programs—Aid to Families with Dependent Children and food stamps—prove substantial, mainly because of variations in rates of participation among the counties. While variables that reflect differences in the conditions for eligibility account for a significant part of the variation, various barriers to participation—including political attitudes, access to welfare offices, and local staffing—are also important. The results suggest that centralized regulation must be retained and strengthened if federal welfare programs are to retain some degree of uniformity within each state.
Advising congressional decision‐makers: Guidelines for economists
Authors: Verdier James M.
Published: July 2010

Economists have less influence on congressional decision‐making than they might because they do not make a sufficient effort to learn how issues look from the politicians' point of view. Politics and economics are inextricably connected in congressional decision‐making. For those economists who are willing to try to bridge the gap between economists and Politicians, the article suggests ten guidelines: (1) learn about the history of the issue; (2) find out who will be making the decision, (3) timing is critical; (4) learn everyone's interests and arguments; (5) it's OK to think like an economist, but don't write like one; (6) keep it simple; (7) congressmen care more about distribution than efficiency; (8) take implementation and administration into account; (9) emphasize a few crucial and striking numbers; and (10) read the newspapers.
Why policy analysis and ethics are incompatible
Authors: Amy Douglas J.
Published: July 2010

Commentators in the field of policy analysis have argued persuasively for the inclusion of ethical evaluations in the analytic process, yet most practitioners in the policy field avoid analyzing moral issues. Standard explanations for this neglect of ethics tend to be inadequate; assertions that normative analysis is unnecessary, impractical, impossible, or undesirable are demonstrably weak. Political factors, on the other hand, provide a clearer understanding of the neglect of ethics. Ethical inquiry is shunned because it frequently threatens the professional and political interests of both analysts and policymakers. The administrator, the legislator, the bureaucracy, and the profession of policy analysis itself all resist the potential challenges of moral evaluation.
Action research: A model for organizational learning
Authors: Comfort Louise K.
Published: July 2010

Traditionally, social research has relied on systematic methods to control variation in the collection of data in order to validate relationships observed among the social phenomena under study. Ironically, many critical problems in the actual operation of public organizations are not amenable to such rigorous controls. An alternative mode of analysis, action research, may prove more useful since it takes into account the dynamic nature of organizations, emphasizing the production of valid information, the element of Fee and informed choice by organization members, and the goal of engendering commitment to action by those involved. Simulated operations designed to enhance the performance of public agencies in unforeseen emergencies provide a setting in which to evaluate the effectiveness of action research as a tool for organizational problem‐solving.
Competitive bidding and states' purchase of services: The case of mental health care in Massachusetts
Authors: Schlesinger Mark , Dorwart Robert A. , Pulice Richart T.
Published: July 2010

Over the past two decades states have significantly increased their use of competitive bidding to purchase health and social services from private agencies. Competitive contracting is thought to facilitate program administration, to reduce costs, and to increase the quality of delivered services. We evaluate these claims in light of Massachusetts' experience with competitive contracting for mental health care. We find that few of the expected benefits are achieved. In practice, supposedly competitive bidding systems often degenerate into administratively complicated negotiations between the state and private monopolies. This results in higher costs and lower quality of services. In light of this negative assessment, three strategies for reform are proposed and evaluate.
The evaluation of economic development conflict is present: Projects where military investing in health care in el salvador
Authors: Vogel Ronald J. , Christianson Jon B.
Published: July 2010

Increasingly, U.S. policymakers have proposed development projects in areas of the world undergoing rapid, disruptive, and often violent challenges to existing political regimes. The U.S. government typically requires that these projects undergo an economic evaluation before they can be implemented. While benefit‐cost theory and practice have made substantial gains over the last 20 years, they are more easily and aptly applied to stable economic and political conditions. This paper raises several issues concerning the theory and practice of benefit‐analysis in an environment where there is political instability and military conflict. The discussion is illustrated by reference a proposed health care project in El Salvador. I t concludes summarizing the options available to policy analysts who conduct evaluations in such situations.
The status of OSHA reform: A comment on mendeloff's proposals
Authors: Viscusi W. Kip
Published: July 2010

Since its inception, the Occupational Safety and Health Administration (OSHA) has been the target of regulatory reform proposals. OSHA has attracted this continued critical attention both because of inadequacies in the design of OSHA regulation and shortcomings in its implementation. John Mendeloff's critique and program of reform for OSHA focus primarily on inadequacies in the structure of OSHA policy rather than its implementation. Within that class of issues, Mendeloff provides a thoughtful analysis of OSHA policy. His regulatory proposals also address what appear to be the principal shortcomings of OSHA. However, the specific aspects of his proposal raise new problems with respect to the stability of regulatory policy and its unintended role in establishing barriers to entry in industry.
Deregulatin and the courts
Authors: Sunstein Cass R.
Published: July 2010

The recent deregulation movement has occupied not only executive agencies and Congress, but the courts as well. Legal challenges to deregulatory measures press traditional doctrines governing judicial review; the traditional role of the courts has been to fend off rather than to help bring about government regulation. These traditions, when joined with contemporary distrust of both regulation and the courts, account for a mounting belief that courts should take a deferential approach to deregulation. But such an approach would be misguided in light of the importance of judicial review in promoting agency adherence to statutes enacted by Congress and in guarding against factional influences over government. Judge‐made doctrines can be developed to make it more likely that deregulation is consistent with law and does not reflect the disproportionate influence of politically powerful groups.
The issue of standing in cost‐benefit analysis
Authors: Whittington Dale , MacRae Duncan
Published: July 2010

Insufficient attention has been given in cost‐benefit analysis to whose benefits are to be counted. Foreigners, illegal aliens, fetuses, and criminals are problematic cases. Persons or entities may be given “standing” by participation in decision processes; by having their preferences counted, if meaningful preferences exist; by having their welfare counted, if they cannot express their preferences; or by representation by others whom they do not choose. Problems of standing arise in the valuation of life, the consideration of future generations and nonhuman entities, and equity weighting. These problem may be treated by altering the scope of the expert community or by interaction between that community and the political community. They are not always resolvable, but should be treated more explicitly.
Cashing out food stamps: Impacts on food expenditures and diet quality
Authors: Devaney Barbara , Fraker Thomas
Published: July 2010

On July 1, 1982, the Commonwealth of Puerto Rico implemented a cash food assistance program, known as the Nutrition Assistance Program, as a replacement for the existing Food Stamp Program. The Nutrition Assistance Program differs from the former Puerto Rico Food Stamp Program in two important respects: cash replaced coupons as the form of issuance and eligibility standards and benefits were reduced to bring program costs into line with a reduced funding level. Based on household food use survey data collected before and after the introduction of the Nutrition Assistance Program, this paper examines the program's impacts on household food expenditures and diet quality. The results of the analysis indicate that the cashing out of food stamp benefits in Puerto Rico had virtually no impact on food expenditures and diet quality, while restrictions on eligibility and benefits under the Nutrition Assistance Program caused a decline in the money value of food used at home of about 2 percent and reductions in the availability of food energy and five specific nutrients ranging from 1.8 to 3.2 percent of the adult male Recommended Dietary Allowances.
How important is information format? An experimental study of home energy audit programs
Authors: Magat Wesley A. , Payne John W. , Brucato Peter F.
Published: July 2010

Among alternative regulatory responses, information provision programs are receiving increasing attention despite the decidedly mixed evidence about their effectiveness. This paper provides detailed experimental evidence to demonstrate that for one important example of an information program, the use of energy audits to stimulate residential energy conservation, the effectiveness of the program is highly sensitive to the information processing behavior of the users of the information. Simple changes in the format of the information provided to homeowners produced marked improvements in the efficiency of consumer choices. The study illustrates Stern's conclusion in a recent issue of this journal that laboratory experimentation provides a useful alternative to model‐based analysis of natural experiments, especially for policy design issues involving information acquisition and processing. The paper also offers conclusions about improving the effectiveness of home energy audits, as well as the entire class of information provision programs.
Industry effects of medical device regulation: The case of diagnostic imaging equipment
Authors: McKay Niccie L.
Published: July 2010

In 1976 Congress passed legislation authorizing the regulation of all medical devices. Some observers predicted that this regulation would have adverse effects on the newly regulated industries. This paper examines the major features of the medical device regulatory program and investigates how the regulation has affected the diagnostic imaging equipment industry. The results indicate that medical device regulation has not materially affected competition or innovation within established product classes in this industry. This suggests that, by choosing methods of regulation that differentiate among levels of potential risk to consumers, the goal of consumer protection can be achieved with fewer undesirable effects on the regulated industry.
Political and organizational analysis in the policy curriculum
Authors: Donalds E. Stokes
Published: July 2010

As the public policy curriculum and teaching faculty were synthesized from a set of existing fields two decades ago, political science was included because the policy school graduates needed some of the knowledge of the structure and processes of government the discipline possessed. But subsequently there has been a profound shift away from this traditional content to a more actor‐centered form of analysis in the political and organizational part of the policy curriculum. This paper examines this content and a basic intellectual issue challenging the faculty who are responsible for this part of the policy curriculum. Their efforts will succeed only as they alter the structure of the discipline or develop a clearer algorithm for an actor‐centered political analysis.
Privatization as institutional choice
Authors: Chamberlin John R. , Jackson John E.
Published: July 2010

A model based upon the common concept of rent‐seeking behavior avoids an exclusive focus on the pecuniary motive in private institutions and the power motive in public institutions. Using this model, the case for privatization ranges from very strong to unpersuasive, with some fascinating intermediate cases. Where purchases are frequent, information is abundant, costs of a bad decision are small, externalities are minimal, and competition is the norm, privatization ought to be pursued. At the other extreme, in situations where externalities and collective interests abound, natural monopolies are dominant, distributional goals are important, or debate and experience will alter preferences, governmental determination of service levels and public provision should continue. Intermediate situations such as those involving education, health, and some aspects of enterprise development provide the most interesting and hotly debated areas. These intermediate situations have both private and collective characteristics, choices are made infrequently with little information, have monumental consequences, distributional considerations are critical, and public debate about the level and type of service substantially affects individual behavior.
Influence of surface treatment of multiwall carbon nanotubes on the properties of polypropylene/carbon nanotubes nanocomposites
Authors: Mičušík Matej , Omastová Mária , Pionteck Jürgen , Pandis Christos , Logakis Emmanuel , Pissis Polycarpos
Published: July 2010

Nanocomposites based on polypropylene (PP) and surface modified multiwall carbon nanotubes (CNT) were prepared by melt mixing. For comparison, unmodified CNT were also used as fillers. The surface modification of CNT was done by treatment with a combination of anionic and cationic surfactants at different molar ratios using week and strong sonication power output during modification. The modification of nanotubes was done to improve the filler dispersibility in the PP matrix. However, the modification of the filler resulted only in small morphological differences of prepared composites, but the electrical conductivity of the samples depends on filler type and content. Mechanical and thermal properties of the nanocomposites were studied and the results are discussed in relation with the preparation parameters during the modification of CNT. Copyright © 2010 John Wiley & Sons, Ltd.
Prototropy and π‐electron delocalization for purine and its radical ions – DFT studies
Authors: Raczyńska Ewa D. , Kamińska Beata
Published: July 2010

Complete tautomeric equilibria and π‐electron delocalization were studied at the B3LYP/6‐311+G** level for neutral purine (P) and its charged radicals (P+• and P−•). All possible nine tautomers (four NH and five CH forms) and all possible 36 tautomeric equilibria (six NiH → NkH, twenty NH → CH, and ten CiH → CkH conversions) were considered. The greatest variations of the tautomeric equilibrium constants (as pKT) were observed for the NH → CH conversions when proceeding from neutral to reduced purine (P + e → P−•). These variations completely change the tautomeric preferences. One‐electron oxidation (P − e → P+•) has considerably smaller effect on the pKT values and does not change the tautomeric preferences. π‐Electron delocalization depends on the position of the moving proton and on the type of the electron transfer. For individual tautomers, some linear relations between the relative stabilities and the HOMA (harmonic oscillator model of aromaticity) indices occur for neutral and oxidized purine. For reduced purine, a scatter plot is found. Copyright © 2010 John Wiley & Sons, Ltd.
Microwave‐assisted synthesis of organic/inorganic hybrid nanocomposites and their encapsulating applications for photoelectric devices
Authors: Lin Jian‐Shian , Chung Ming‐Hua , Chen Chen‐Ming , Juang Fuh‐Shyang , Liu Lung‐Chang
Published: July 2010

UV curable organic/inorganic hybrid nanocomposites with high refractive indices, moderate hardness, good adhesive strength, and excellent gas blocking performances have been successfully rapidly synthesized by in situ microwave‐assisted heating process. We find that the chemical structures of polymer matrices influence the physical properties and addition of silicone and polyurethane (PU) into the acrylics backbone can further reduce the gas permeation and increase the adhesive strength as well as refractive indices. Moreover, lab‐made Silicone/PU/Acrylics I nanocomposites have also been utilized for the encapsulation of organic solar cells, LEDs, OLEDs, and flexible OLEDs. The experimental results demonstrate that they can effectively hinder the penetration of oxygen as well as moisture in the atmosphere into the photoelectric devices, consequently prolonging their lifetimes. Copyright © 2010 John Wiley & Sons, Ltd.
Nucleophilic reactivities of tertiary alkylamines
Authors: Ammer Johannes , Baidya Mahiuddin , Kobayashi Shinjiro , Mayr Herbert
Published: July 2010

The kinetics of the reactions of tertiary amines, triethylamine (1a), N‐methylpyrrolidine (1b), N‐methylpiperidine (1c), and N‐methylmorpholine (1d) with benzhydrylium ions (Ar2CH+) have been studied in acetonitrile and dichloromethane. The benzhydryl cations were generated by laser flash photolysis of quaternary phosphonium and ammonium tetrafluoroborates. For most reactions, exponential decays of the absorbances of the benzhydryl cations were observed because the carbocations were generated in the presence of a high excess of the amines (pseudo‐first‐order conditions). From the linear plots of kobs versus the amine concentrations, the second‐order rate constants k were obtained, which allowed us to calculate N and s for these amines in CH3CN and CH2Cl2. The linear free energy relationship log k = s(N + E) was thus used to integrate 1a–d into our comprehensive nucleophilicity scales. Copyright © 2010 John Wiley & Sons, Ltd.
Theoretical study of substituent effects on gas‐phase stabilities of benzylic anions
Authors: Nakata Kazuhide , Fujio Mizue , Nishimoto Kichisuke , Tsuno Yuho
Published: July 2010

The substituent effects on the relative gas‐phase stabilities of 16 kinds of benzylic anion systems were determined theoretically using proton transfer reactions. The energies and geometries of ring‐substituted anions and corresponding neutral species, which are involved in the reactions, were calculated at the B3LYP/6‐311+G(2d,p) level of theory. The obtained substituent effects were compared with one another to reveal that the gas‐phase stabilities of benzylic anions are governed by an inductive effect and two additive effects. By considering the geometrical changes of the anions, these two effects were assigned to resonance and saturation effects, which stabilize anions by para +R groups and electron‐releasing (ER) groups, respectively. The saturation effect was found for not only para but also meta substituents and functions through both π and σ bonds. Statistical analyses of the substituent effects ascertained that the behavior of the substituent effects can be quantitatively described by three terms – that of the inductive effect, the resonance effect, and the saturation effect – using an extended Yukawa–Tsuno equation, $ - \Delta E_{X} = \rho (\sigma {}^{0} + r^{ - } \Delta \bar {\sigma }_{R}^{ - } + s\Delta \bar {\sigma }_{S} )$. Copyright © 2010 John Wiley & Sons, Ltd.
Rhodium‐catalysed hydrogenation of enamides with monodentate phosphorous ligands. A density functional theory study
Authors: Schiaffino Luca , Ercolani Gianfranco
Published: July 2010

The hydrogenation of enamides catalysed by rhodium complexes of monodentate phosphorous ligands has been studied by density functional theory. The role of trans intermediates, made accessible by the non‐chelating nature of the ligand, has been taken into account. The findings here reported show that cis intermediates play the major role in the mechanism of the reaction, suggesting that data obtained with chiral monodentate phosphorous ligands or with a mixture of them should be interpreted excluding the intervention of structures with trans phosphine arrangement. Thus, results observed with monodentate phosphorous ligands must be interpreted in the light of the exclusive intervention of cis intermediates, without involvement of structures with trans phosphine arrangements. Copyright © 2010 John Wiley & Sons, Ltd.
Determination of Solvent Contamination and Characterization of Ultrafine HNS Particles after Solvent Recrystallization
Authors: Kaur Jatinder , Arya Vandana P. , Kaur Gurvinder , Gupta Yashpal P. , Verma Manmohan M. , Lata Prem
Published: July 2010

Solvent–antisolvent recrystallization employed for size reduction of HNS has been described and the effect of various parameters such as stirring rate, effect of antisolvent type, antisolvent temperature, ultrasonication, etc. was investigated. Purified HNS, produced by hot solvent recrystallization of production grade crude HNS, of mean particle size ∼95 μm was used for preparation of ultrafine particles of HNS. Solvent contamination in terms of residual solvent was determined by 1H NMR and GC‐MS analysis. In addition, ultrafine HNS has been characterized for purity (HPLC, 1H NMR), particle size and shape (PSA and SEM), specific surface area (BET analysis), thermal behavior (TGA, DSC), sensitivity (impact, friction), etc. The results have been compared with C‐HNS. UF‐HNS was >99% pure with mean particle size <1 μm. SEM showed submicrometer size rods like particles of HNS as the final material.
Berberine elicits anti‐arrhythmic effects via IK1/Kir2.1 in the rat type 2 diabetic myocardial infarction model
Authors: Wang Li‐hong , Yu Chang‐hua , Fu Ying , Li Qiang , Sun Yu‐qian
Published: July 2010

The purpose of this study was to explore the anti‐arrhythmic mechanisms of berberine in diabetic rats with myocardial infarction. Sixty rats were divided into four groups: (1) normal control; (2) myocardial infarction group (MI); (3) Type 2 diabetes with myocardial infarction group (T2DM+MI); and (4) Type 2 diabetic with myocardial infarction berberine‐treated group (BBR). Berberine (60 mg/kg/day) was administered after coronary artery ligation in the T2DM+MI group for 14 days. Currents were measured using whole‐cell patch‐clamp techniques. Western blot was performed for quantification of target proteins. The study showed that arrhythmias induced by myocardial infarction were aggravated in diabetic rats. Arrhythmia scores in the MI group were significantly higher than in the control group. Interestingly, the administration of berberine at a dose of 60 mg/kg/d recovered arrhythmia scores (P > 0.05). RMP (Resting membrane potential) which could be recovered by berberine (P < 0.05), was significantly reduced in both the infarction groups. IK1 current and current density markedly decreased in the MI and T2DM+MI groups (P < 0.05) and could be reversed by berberine (P < 0.05). The relative expression of Kir2.1 in rats in the MI and T2DM+MI group were both significantly decreased (P < 0.05); berberine recovered depressed Kir2.1 to nearly normal levels. The results suggest that the effects of berberine on IK1/Kir2.1 may be an important mechanism for producing anti‐arrhythmic effects. Copyright © 2010 John Wiley & Sons, Ltd.
Antibacterial activity of flavonoids from the stem bark of Erythrina caffra thunb.
Authors: Chukwujekwu J. C. , Van Heerden F. R. , Van Staden J.
Published: July 2010

The antibacterial activity of the stem bark of Erythrina caffra Thunb. was investigated against different bacterial strains. The antibacterial activity was determined by a micro broth dilution assay. Antibacterial compounds were isolated and identified using a Bruker Avance III LPO NMR spectrometer. Four known flavonoids, abyssione‐V 4′‐O‐methyl ether, 6,8‐diprenylgenistein, alpinumisoflavone and burttinone, were isolated. All the compounds were active against both Gram‐negative and Gram‐positive bacteria. The minimum inhibitory concentration values obtained (MIC) ranged from 3.9 μg/mL to 125 μg/mL. This is the first report of antibacterial activity of burttinone and the isolation of these compounds from E. caffra. Copyright © 2010 John Wiley & Sons, Ltd.
Red cloverTrifolium pratense(Linn.) isoflavones extract on the pain threshold of normal and ovariectomized rats – a long‐term study
Authors: Vishali Nagarajan , Kamakshi Krishnaswamy , Suresh Sekar , Prakash Seppan
Published: July 2010

Depletion of estrogens occurs in women during menopause, while in experimental animals, oophorectomy is a common method to deplete the animals of their gonadal hormones. Recently, phytoestrogens derived from plants have been tried as estrogen substitutes during menopause. In the present study an isoflavones methanol extract from red cloverTrifolium pratense(Linn.) was administered orally (500 mg/kg of body weight) to ovariectomized (OVX) and normal (controls) rats for 90 and 180 days. Their pain threshold was monitored using tail flicking and formalin test methods. Observations showed that the OVX rat pain threshold was reduced due to estrogen deprivation, whereas the pain threshold levels in OVX rats treated with isoflavones extract was similar to the control animals. The present study demonstrated the influence of phytoestrogen on long‐term OVX rats in pain perception in the absence of ovarian estrogen and without toxic side effects. However, the actions of gonadal hormones on nociceptive axis are myriad and complex, so further studies on the exact physiological mechanism of the phytoestrogen action on nociceptive axis is warranted. Copyright © 2010 John Wiley & Sons, Ltd.
Suppression of ovalbumin‐induced airway inflammatory responses in a mouse model of asthma by Mimosa pudica extract
Authors: Yang Eun Ju , Lee Ji‐Sook , Yun Chi‐Young , Ryang Yong Suk , Kim Jong‐Bae , Kim In Sik
Published: July 2010

Asthma is an inflammatory airway disease. The pathogenic mechanisms of asthma include the infiltration of leukocytes and release of cytokines. Mimosa pudica (Mp) has been used traditionally for the treatment of insomnia, diarrhea and inflammatory diseases. Although Mp extract has various therapeutic properties, the effect of this extract on asthma has not yet been reported. This study investigated the suppressive effects of Mp extract on asthmatic responses both in vitro and in vivo. Mp extract was acquired from dried and powdered whole plants of M. pudica using 80% ethanol. BALB/c mice were used for the mouse model of asthma induced by ovalbumin. Mp extract significantly inhibited the HMC‐1 cell migration induced by stem cell factor and blocked the release of monocyte chemotactic protein‐1 (MCP‐1) and interleukin‐6 (IL‐6) in EoL‐1 cells. Leukocytosis, eosinophilia and mucus hypersecretion in asthmatic lung were significantly suppressed by Mp extract. The release of ovalbumin‐specific IgE in bronchoalveolar lavage fluid and serum was also decreased. Mp extract treatment resulted in no liver cytotoxicity. The Mp extract has inhibitory properties on asthma and may be used as a potent therapeutic agent for allergic lung inflammation. Copyright © 2010 John Wiley & Sons, Ltd.
Antidiabetic activity of resveratrol, a known SIRT1 activator in a genetic model for type‐2 diabetes
Authors: Sharma Sameer , Misra Chandra Sekhar , Arumugam Surendar , Roy Subhasis , Shah Vanya , Davis Joseph Alex , Shirumalla Raj Kumar , Ray Abhijit
Published: July 2010

In the present study, resveratrol, a polyphenolic SIRT1 activator was evaluated for its SIRT1 activation in an in vitro fluorescent based assay (EC50: 7 μM). The efficacy of resveratrol was also evaluated in ob/ob mice for its antidiabetic and associated metabolic effects. Mice aged 5–8 weeks were included in four groups; control and resveratrol at 5, 15, 50 mg/kg, b.i.d. and were dosed orally. After 4 weeks of drug treatment, body weights were noted and random blood glucose and insulin was estimated for the antidiabetic effect. Animals were also subjected to the oral glucose tolerance test to observe any improvement in the glucose excursion. Triglycerides, total cholesterol, adiponectin and free fatty acid levels were also estimated. The results showed that resveratrol exhibited significant antihyperglycemic activity with an improvement in the insulin levels compared with the control mice. There was also a significant improvement observed in the glucose excursion in the oral glucose tolerance test performed for 120 min; although an insignificant improvement in the triglycerides, total cholesterol, adiponectin and free fatty acid levels was observed at different doses of resveratrol tested. The present findings suggest that resveratrol is an antihyperglycemic agent and drugs similar to resveratrol can be considered as an effective therapeutic adjuvant for the current treatment of diabetes mellitus. Copyright © 2010 John Wiley & Sons, Ltd.
Essential Oil from Citrus aurantifolia prevents ketotifen‐induced weight‐gain in mice
Authors: Asnaashari Solmaz , Delazar Abbas , Habibi Bohlol , Vasfi Roghayeh , Nahar Lutfun , Hamedeyazdan Sanaz , Sarker Satyajit D.
Published: July 2010

Obesity is a major health problem world‐wide. Medical intervention is often needed to tackle this problem, and accordingly the need for developing more effective, safer and cheaper weight reducing drugs has become paramount in recent years. In the present study, the effects of lime (Citrus aurantifolia) essential oils in reducing body weight, individually and in co‐administration with ketotifen, an antihistaminic drug that causes weight‐gain, has been investigated using a mouse model. During the 45 days experimental period, the mice that received ketotifen demonstrated an enhancement both in the amount of food intake and body weight compared with the control group. Groups treated with lime essential oil displayed a reduction in body weight and food consumption in mice, possibly through promoting anorexia which might have played a role in weight loss. Interestingly, co‐administration of the lime essential oil and ketotifen caused significant suppression in gaining weight, as well as decreased body weights of mice. The data obtained in this study suggested that lime essential oil plays an important role in weight loss and could be useful in the treatment of drug‐induced obesity and related diseases. The GC‐MS analysis of the essential oils of C. aurantifolia was also performed and approximately 22 main components, with limonene (28.27%) being the principal one, were identified and quantified. Copyright © 2010 John Wiley & Sons, Ltd.
Antiprotozoal activity of Melampyrum arvense and its metabolites
Authors: Kirmizibekmez Hasan , Atay Irem , Kaiser Marcel , Brun Reto , Cartagena Michelle M. , Carballeira Néstor M. , Yesilada Erdem , Tasdemir Deniz
Published: July 2010

An activity guided isolation of the H2O subextract of the crude extract of Melampyrum arvense L. afforded iridoid glucosides: aucubin (1), melampyroside (2), mussaenoside (3), mussaenosidic acid (4), 8‐epi‐loganin (5); flavonoids: apigenin (6), luteolin (7), luteolin 7‐O‐β‐glucopyranoside (8); a lignan glycoside dehydrodiconiferyl alcohol 9‐O‐β‐glucopyranoside (9); and benzoic acid (10). β‐Sitosterol (11) and a fatty acid mixture (12) were identified as the active principles of the CHCl3 subextract. The structures of the isolates were elucidated by spectroscopic methods, while the composition of 12 was identified by GC‐MS after methylation. Luteolin (7) appeared as the most active compound against Trypanosoma brucei rhodesiense and Leishmania donovani (IC50 values 3.8 and 3.0 μg/mL). Luteolin 7‐O‐β‐glucopyranoside (8) displayed the best antiplasmodial activity against Plasmodium falciparum (IC50 value 2.9 μg/mL). This is the first detailed phytochemical study on Turkish M. arvense and the first report of the antiprotozoal effect of Melampyrum species and its constituents. Copyright © 2010 John Wiley & Sons, Ltd.
Antioxidant activity of yellow dock (Rumex crispus L., Polygonaceae) fruit extract
Authors: Maksimović Zoran , Kovačević Nada , Lakušić Branislava , Ćebović Tatjana
Published: July 2010

The methanol extract of ripe Rumex crispus L. fruits was evaluated for its antioxidant potential by assays for ferric‐reducing antioxidant power (FRAP), DPPH‐free radical scavenging activity (DPPH) and the influence on lipid peroxidation in liposomes (LP). Considerable activity was observed in all test systems (FRAP: 9.9 mmol Fe2+/g; DPPH IC50: 3.7 μg/mL; LP IC50: 4.9 μg/mL), comparable to that of BHT (FRAP: 8.0 μg/mL; DPPH IC50: 19.4 μg/mL; LP IC50: 3.5 μg/mL), but lower than the activity of ascorbic acid, rutin and quercetin, used as positive control substances. The in vivo effects were evaluated in several hepatic antioxidant systems (activities of LPx, GSH‐Px, Px, CAT and XOD, as well as GSH content), after treatment with the studied yellow dock extract in different doses, or in combination with carbon tetrachloride (CCl4). Pretreatment with the R. crispus extract inhibited CCl4‐induced oxidative stress by decreasing LPx and increasing GSH content in a dose dependent manner, bringing the levels of antioxidant enzymes to near control values. Copyright © 2010 John Wiley & Sons, Ltd.
Changes in Northern Hemisphere stratospheric variability under increased CO2 concentrations
Authors: Bell Christopher J. , Gray Lesley J. , Kettleborough Jamie
Published: July 2010

The robustness of stratospheric circulation changes under increased concentrations of carbon dioxide are investigated using the Met Office HadSM3‐L64 model. Equilibrium climate change simulations employing forcing of two and four times pre‐industrial CO2 are presented, with particular focus on the temperature response of the Arctic lower stratosphere during Northern Hemisphere winter. High CO2 loading provides the ability to attain the statistical significance of any response, typically a problem given the large component of interannual variability common to the region. In response to CO2, the expected global stratospheric cooling is modified by an anomalous dynamical warming of the Arctic winter lower stratosphere. This warming is shown to be associated with an increase in frequency of stratospheric sudden warming (SSW) events. At four times pre‐industrial CO2, the frequency of SSW events per year is doubled with respect to the control simulation. Further, by comparing winters with and without SSW events, it is shown that the warming of the lower stratosphere cannot be achieved without the presence of a frequency modulation of SSW events. Copyright © 2010 Royal Meteorological Society and Crown Copyright.
Impurity cluster effects in high‐ and low‐doping semiconductor materials
Authors: Ferreira Da Silva A.
Published: July 2010

The cluster‐like impurity effect in semiconductor materials as Si, GaN, GaAs, and 4HSiC for impurity concentrations spanning the metallic to the insulating regimes, i.e., from high‐ to low‐doping concentration, has been investigated at low temperature. To metallic regime a critical impurity concentration for metal–nonmetal transition is estimated from a highly correlated system by a doubly doped H‐like different impurity pairs. For insulating regime, the absorption measurements reveal low‐energy absorption peaks identified as electronic transitions in three‐donor clusters. The many‐particle correlation via a multi‐configurational self‐consistent field model is used in the calculation. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
The influence of electron donor and electron acceptor groups on the electronic structure of the anti‐inflammatory tripeptide Cys‐Asn‐Ser
Authors: Soriano‐correa Catalina , Barrientos‐salcedo Carolina , Raya Angélica , Póo Consuelo Rubio , Esquivel Rodolfo O.
Published: July 2010

It has been discussed in the literature that electron delocalization along the peptide backbone and side chain modulates the physical and chemical features of peptides and proteins. The structure and properties of peptides are determined by their charge‐density distribution, such that the modification of its side chain plays an important role on its electronic structure and physicochemical properties. Research on Entamoeba histolytica soluble factors led to the identification of the pentapeptide Met‐Gln‐Cys‐Asn‐Ser, with anti‐inflammatory in vivo and in vitro effects. A synthetic pentapeptide, Met‐Pro‐Cys‐Asn‐Ser, maintained the same anti‐inflammatory actions in experimental assays. A previous theoretical study allowed proposing the Cys‐Asn‐Ser tripeptide (CNS tripeptide) as the pharmacophore group of both molecules. This theoretical hypothesis was recently confirmed experimentally. The objective of this work was to study the influence of the electron donor and electron withdrawing substituent groups on the electronic structure and physicochemical properties of the CNS tripeptide derivatives through a theoretical study at the density functional theory level of theory. Our results in deprotonation energies showed that the relative acidity of hydrogen atom (H2) of the serine‐amide group increases with the electron withdrawing groups. This result was confirmed by means of a study of bond order. The proton affinities illustrated that the electron donor groups favored the basicity of the amino group of the cysteine amino acid. Atomic charges, Frontier molecular orbitals (HOMO–LUMO), and electrostatic potential isosurface and its geometric parameters permitted to analyze the effect that provoked the electron donor and electron attractor groups on its electronic structure and physicochemical features and to identify some reactive sites that could be associated with the anti‐inflammatory activity of tripeptide CNS derivatives. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110:2398–2410, 2010
DFT study of ferroelectric properties of the copolymers: Poly(vinylideneflouride‐trifluoroethylene) and poly(vinylidene fluoride‐chlorotrifluoroethylene)
Authors: Ortiz E. , Cuán A. , Badillo C. , Cortés‐Romero C.M. , Wang Q. , Noreña L.
Published: July 2010

A theoretical study of poly(vinylidene flouride‐trifluoroethylene) and poly(vinylidene fluoride‐chlorotrifluoroethylene, is presented. By density functional theory calculations, some of the properties of these materials have been obtained. Among such properties, the dipolar moment and the energies associated to the structural changes. The B3LYP functional and 6311+G(d,p) bases set were used with Gaussian program. Calculations associated to different conformations were carried out to get insight about the involved phase changes. The energetic, charges, and dipole moment were calculated. The conformations, namely, I = Tp, II = TGa, and III = TGp, where T means trans and G means gauche, for the two polymers aforementioned were compared with the poly(vinilydene fluoride) studies previously obtained. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110:2411–2417, 2010
A theoretical study of the CH2N isomers: Molecular structure and energetics
Authors: Puzzarini Cristina
Published: July 2010

Molecular structure and energetics of the four isomers of CH2N, namely H2CN, trans‐HCNH, cis‐HCNH, and H2NC, have been investigated by means of a highly accurate level of theory, i.e., using the coupled cluster method in conjunction with correlation consistent basis sets ranging in size from triple to sextuple zeta. Extrapolation to the complete basis set limit, higher excitations in the cluster operator as well as core correlation and relativistic effects have been considered. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110:2483–2494, 2010
Quantum chemical study of the mechanism of action of vitamin K carboxylase in solvent
Authors: Wu Sangwook , Liu Shubin , Davis Charles H. , Stafford Darrel W. , Pedersen Lee G.
Published: July 2010

We investigate the post‐translational generation of Gla (γ‐carboxyglutamic acid) from Glu (glutamic acid) by vitamin K carboxylase (VKC) in solvent. VKC is thought to convert vitamin K, in the vitamin K cycle, to an alkoxide‐epoxide form, which then reacts with CO2 to generate an essential ingredient in blood coagulation, γ‐carboxyglutamic acid (Gla). The generation of Gla from Glu is found to be exergenic (−15 kcal/mol) in aqueous solution with the SM6 method. We also produced the free energy profile for this model biochemical process with other solvent methods (polarizable continuum model, dielectric polarizable continuum model) and different dielectric constants. The biological implications are discussed. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
On the time‐dependent solutions of the Schrödinger equation. I. The linear time‐dependent potential
Authors: Palma A. , Villa M. , Sandoval L.
Published: July 2010

The solution of the Schrödinger equation for the linear time‐dependent potential has recently been the subject of several publications. In this report, we show this is one of the few systems that leads to a solvable Lie algebra. In fact, we consider a more general problem where the linear time‐dependent potential is only a particular case. The solution is found by using the well‐known theorem of Wei‐Norman. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Simulation of oriented collision dynamics of simple chiral molecules
Authors: Lombardi A. , Palazzetti F. , Maciel G. S. , Aquilanti V. , Sevryuk M. B.
Published: July 2010

With the aim of illustrating computationally the mechanism of chiral discrimination induced by molecular collisions, we present results of extensive classical dynamics simulations of oriented collisions of rare gas atoms with prototypical chiral molecules, such as hydrogen peroxide and hydrogen persulfide. Models for the intermolecular and intramolecular interactions are based on previous quantum chemical calculations. The phenomenon of right‐left asymmetry in scattering directions is documented both by exemplary single trajectories and by angular distributions obtained by statistical averagings. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Fourteen easy lessons in density functional theory
Authors: Perdew John P. , Ruzsinszky Adrienn
Published: July 2010

Density functional theory (DFT) is now the most commonly used method of electronic structure calculation in both condensed matter physics and quantum chemistry, thanks in part to the focus it has received over the first 50 years of the Sanibel Symposium. We present a short history, and review fourteen short and easy but important lessons about nonrelativistic DFT, with some partiality but with a minimum of technical complication. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
QR‐SCMEH‐MO calculations on inner‐transition metal diatomic molecules having 12 valence electrons‐Nd2 and U2
Authors: Boudreaux Edward A. , Baxter Eric C.
Published: July 2010

The QR‐SCMEH‐MO computational method has been developed and tested on a numerous variety of inorganic systems over some 45‐plus years, with surprisingly good success. More recently this method has been applied to the transition metal molecules, Cr2, Mo2, W2, and Sg2 with 12 valence d/s electrons. The results were at least as good as those obtained from the most accurate ab initio and DFT methods currently available. An extension of the method has been made to the diatomic 12 valence electrons, f/s orbital systems, Nd2 and U2, which is the topic of this presentation. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010