bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensory Neuropathy in Hypothyroidism: Electrophysiological and Clinical Findings
Authors: Yeasmin Sabina , Begum Noorzahan , Begum Shelina , Rahman Shah M Hafizur
Published: January 2009

Peripheral neuropathy may be a manifestation of hypothyroidism which usually develops insidiously over a long period of time due to irregular taking of drugs or lack of thyroid hormone replacement. The present study was designed to observe the clinical and electro-physiological findings in hypothyroid patients in order to evaluate the neuromuscular dysfunction as well as sensory neuropathy. For this purpose, 70 subjects with the age range of 20 to 50 years of both sexes were included in the study. Among them, 40 hypothyroid patients were taken in study group (Group B) and 30 aparently healthy subjects were taken as control (Group A). On the basis of their TSH levels, group B was further divided into group B1 with TSH <60 MIU /L or (less severe) and group B2 with TSH >60 MIU /L (severe group). The duration of the disease ranged from 6 months to 5 years. All the hypothyroid patients were selected from Thyroid Clinic, Center of Nuclear Medicine and Ultra sound, Dhaka Medical College and Hospital, Dhaka, during the period from January 2005 to December 2005. Healthy subjects were selected from personal contact. Most of the hypothyroid patients were under hormone replacement therapy. Diagnosis of hypothyroidism was done by serum levels of TT3, TT4 and the TSH. In this study, both TT3, TT4 levels were significantly (P<0.01) lower in hypothyroids in comparison to those of control. The patients were searched for the clinical signs of sensory neuropathy. Clinical findings revealed diminished or absence of most of the deep tendon reflexes. The nerve conduction studies for sensory nerve function were done in all the subjects by electrophysiological technique. All the tests were done in median and ulnar nerve for upper limb and in sural nerve for lower limb and these parameters were measured on the day 1 (one) of their first visit. Data were compared among the different groups. Most of the patients had higher sensory distal latencies (SDL) with lower conduction velocities (SNCV) which were more marked in severe cases. About 67.5% of hypothyroid patients had shown abnormal sensory NCV when compared to that of euthyroids. Therefore, this study concludes that sensory neuropathy may be a consequence of hypothyroidism. Key Words: Hypothyroidism; Neuropathy; ElectrophysiologyDOI:10.3329/jbsp.v2i0.975  J Bangladesh Soc Physiol. 2007 Dec;(2): 1-6.
Total Count of White Blood Cells in Adult Male Smokers
Authors: Islam Mohammed Montasir , Amin Md Ruhul , Begum Shameema , Akther Dilruba , Rahman Abedur
Published: January 2009

The present study was carried out to observe the changes in total count in WBC in cigarette smokers. The study population consisted of 105 adult male smokers and non-smokers, aged 20~40 years, from different socio-economic classes. Among them, 30 apparently healthy non-smokers were taken as control. 75 apparently healthy smokers, who had the history of smoking of one or more cigarette per day, regularly for at least last one year, were taken as the study group. Smokers were again subdivided into three categories according to the number of cigarettes they consumed per day. For statistical analysis unpaired ‘t' test was used for comparison. Mean ± SD of Total count of WBC in non smokers and smokers were 7501.66 ± 929.4 /mm3 and 9171.3 ± 1037.7/mm3 respectively. Smokers had significantly (P<0.001) higher WBC counts than non-smokers. In addition, WBC count was found increased with intensity of smoking. The smokers who were smoking e 20 cigarettes per day had the higher total WBC count than those who were smoking lesser. The findings of the present study suggest that cigarette smoking may cause increased the total count of WBC, which may predict high risk for some fatal diseases. Key words: Cigarette Smoking; White Blood Cell; Adult Male DOI:10.3329/jbsp.v2i0.985 J Bangladesh Soc Physiol. 2007 Dec;(2): 49-53
Effect of Ocimum sanctum Linn (Tulsi) on body weight and some biochemical parameters in restraint stressed albino rats
Authors: Siraji Dilruba , Islam Nadira , Begum Noorzahan , Ferdousi Sultana
Published: January 2009

Background: With the increased trend of urbanization of our society, the incidence of various stress related diseases are increasing day by day. People under chronic stress often tends to seek relief through drugs, which may have side effects. But some natural supplements called adaptogen, can be more beneficial in reducing symptoms of stress. Objective: The present animal model experimental study was designed to observe the effects of restraint stress on body weight, serum ALT, AST, Glucose, Cholesterol and their modifications by Ocimum sanctum Linn (tulsi) pretreatment which is an Ayurvedic adaptogen and has a long history of therapeutic use. Study design: For this purpose, 30 albino rats aged 90 to 120 days were included in this study. Twenty rats of experimental group were further subdivided into two groups. One group consisted of 10 rats exposed to one hour restraint stress daily for 7 days and 10 rats of the second group were pretreated with tulsi for 7 days before exposure to stress in the same way. 10 non stressed , non pretreated rats were taken into control group.This study was undertaken in the laboratory of the Department of Physiology,BSMMU during the period from July 2003 to June 2004. Methods: The body weight of all control rats were recorded daily in the morning. Body weight of the experimental rats were recorded just before exposure to stress. After completing the experiment , the animals were sacrificed and blood was collected . Serum glucose, cholesterol and ALT,ASTwere determined by standard laboratory technique. Data were compared among the groups and the results were statistically analyzed using unpaired student t' test. Results : The body weight in untreated stressed group was significantly lower (p < 0.001) than those of the control group and tulsi pretreated group. Serum levels of glucose, cholesterol, aminotrasferases (ALT and AST) were significantly higher (p < 0.001) in stressed group than those of control . Again in Tulsi treated group all these biochemical parameters were significantly lower (p < 0.001) than those of stressed group. This restraint stress-induced changes in body weight and biochemical parameters may be due to hypophagia, altered secretion of various metabolic hormones and neurotransmitters, changes in membrane permeability & hypovolaemia resulting from stress induced secretion of corticosterone and epinephrine through hypothalamo-pituitary adrenal axis activation. Conclusion: Prevention of stress induced changes in biochemical parameter by tulsi pre treatment indicates its anti stressor effect. Key words: Restraint stress; adaptogen;Ocimum sanctum Linn (tulsi); glucose; cholesterol; ALT; AST. Â  doi: 10.3329/jbsp.v3i0.1791 J Bangladesh Soc Physiol.2008 Dec;(3):29-34. Â
Relationship Between Obesity And Parasympathetic Nerve Function
Authors: Akhtar Shahin , Begum Noorzahan , Ferdousi Sultana , Begum Shelina , Ali Taskina
Published: January 2009

Back ground: Obesity is a potential risk factor for cardiovascular morbidity and mortality. As certain cardiovascular disorders associated with autonomic nerve which dysfunction often coexist in obese persons, investigations of autonomic nerve function especially parasympathetic nerve function in obese, for detection of early autonomic impairment can be potentially important to prevent complications. Objective: The present study was done to observe the parasympathetic nerve function status in obese persons in order to investigate the relationship of autonomic nerve function with obesity. Study design: This study was conducted in the department of Physiology of Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh during July 2006-June 2007. For these 40 apparently healthy obese subjects of both sexes with BMI â¥ 25 kg/sqm. were included in study group. Age and sex matched 40 apparently healthy non obese subjects with BMI range 18.5-22.9 kg/sqm. were taken as control for comparison. Methods: To assess parasympathetic nerve function status, heart rate response to valsalva(valsalva ratio), heart rate response to deep breathing and heart rate response to standing (30th:15th ratio) were determined by 3 noninvasive cardiovascular reflex tests. Data were collected by recording ECG of all subjects under test condition. The correlations of these parasympathetic nerve function parameters with BMI were also studied. Unpaired Student ât' test and Pearson correlation coefficient test were used for statistical analysis. Results: Valsalva ratio (1.47Â±0.24 vs 1.67Â±0.31), HR response to deep breathing (19.62Â±5.55 vs 27.59Â±6.51) and HR response to standing (1.07Â±0.07 vs 1.13Â±0.018) were significantly decreased in obese subjects than those of non obese control. All these parameters were negatively correlated with BMI. and these relatioship were statistically significant. Conclusion: The results of this study indicate that parasympathetic nerve function may be reduced in apparently healthy obese subjects. Key words: Obesity; valsalva; parasympathetic; deep breathing. Â  doi: 10.3329/jbsp.v3i0.1797 J Bangladesh Soc Physiol.2008 Dec;(3):50-54.
Serum Total Protein and Albumin Levels in Different Grades of Protein Energy Malnutrition
Authors: Chowdhury Md Serajul Islam , Akhter Nayeema , Haque Mahmudul , Aziz Rehana , Nahar Nazibun
Published: January 2009

The present study has been designed to estimate serum total protein and albumin levels in different grades of protein energy malnutrition and this will be helpful in early diagnosis, management and rehabilitation of PEM. The serum total protein and albumin levels were studied on 20 healthy children and 30 children suffering from protein energy malnutrition of different grades. Serum total protein and albumin levels of different grades of protein energy malnutrition were significantly lowered than that of control. Lowering being maximum in grade III PEM. This lowering of total protein and albumin occur in any form of PEM and related to severity of the disease. doi: 10.3329/jbsp.v3i0.1799 J Bangladesh Soc Physiol.2008 Dec;(3):58-60.
Preparation of Surface Adsorbed and Impregnated Multi-walled Carbon Nanotube/Nylon-6 Nanofiber Composites and Investigation of their Gas Sensing Ability
Authors: Lala Neeta L. , Thavasi Velmurugan , Ramakrishna Seeram
Published: January 2009

We have prepared electrospun Nylon-6 nanofibers via electrospinning, and adsorbed multi-walled carbon nanotubes (MWCNTs) onto the surface of Nylon-6 fibers using Triton® X-100 to form a MWCNTs/Nylon-6 nanofiber composite. The dispersed MWCNTs have been found to be stable in hexafluoroisopropanol for several months without precipitation. A MWCNTs/Nylon-6 nanofiber composite based chemical sensor has demonstrated its responsiveness towards a wide range of solvent vapours at room temperature and only mg quantities of MWCNTs were expended. The large surface area and porous nature of the electrospun Nylon-6/MWCNT nanofibers facilitates greater analyte permeability. The experimental analysis has indicated that the dipole moment, functional group and vapour pressure of the analytes determine the magnitude of the responsiveness.
Titanium(IV)/Tridentate BINOL Derivative as Catalyst for meso‐Aziridine Ring‐Opening Reactions: High Enantioselectivity, Strong Positive Non‐Linear Effect and Structural Characterization
Authors: Yu Rongmin , Yamashita Yasuhiro , Kobayashi Shū
Published: December 2008

A titanium‐based chiral Lewis acid was found to be effective for the ring‐opening reactions of meso‐aziridines with aniline nucleophiles. The products were generally isolated in high yields and with high to excellent enantioselectivity. The catalytic system was studied by X‐ray single crystal analysis. In experiments on non‐linear effects a strong non‐linear effect of the catalyst system was observed.
Stereoselective Synthesis of Conjugated Bisallenols as Precursors of Novel Bis(2,5‐dihydrofuran) Derivatives
Authors: Poonoth Manojkumar , Krause Norbert
Published: December 2008

A stereoselective synthesis of conjugated bis(α‐hydroxyallenes) by copper‐mediated SN2′‐substitution is described. Their silver‐ or gold‐catalyzed cycloisomerization affords highly functionalized 2‐allenyl‐substituted 2,5‐dihydrofurans and bis(2,5‐dihydrofurans) under axis‐to‐center chirality transfer.
An Efficient Domino Approach for the Synthesis of Multisubstituted Pyrroles via Gold/Silver‐Catalyzed Amination/Cycloisomerization of (Z)‐2‐En‐4‐yn‐1‐ols
Authors: Lu Yuhua , Fu Xiaoping , Chen Haoyi , Du Xiangwei , Jia Xueshun , Liu Yuanhong
Published: December 2008

An efficient and one‐pot synthesis of multisubstituted pyrroles with high diversity and in a regioselective manner from the reactions of suitably substituted (Z)‐enynols with amines or sulfonamides under mild reaction conditions has been developed. This synthesis was realized via a cascade process in the presence of gold/silver (Au/Ag) or boron trifluoride⋅etherate/gold/silver (BF3⋅Et2O/Au/Ag) catalysts, which could catalyze amination and cycloisomerization reactions in the same vessel.
TEMPO‐tert‐Butyl Nitrite: An Efficient Catalytic System for Aerobic Oxidation of Alcohols
Authors: He Xijun , Shen Zhenlu , Mo Weimin , Sun Nan , Hu Baoxiang , Hu Xinquan
Published: December 2008

A metal‐free catalytic system consisting of 2,2,6,6‐tetramethylpiperidineN‐oxyl (TEMPO) andtert‐butyl nitrite has been developed to activate molecular oxygen for the aerobic oxidation of alcohols. A variety of active and non‐active alcohols were oxidized to their corresponding carbonyl compounds in high selectivity and yields.
Reduction of Alkyl Halides by Triethylsilane Based on a Cationic Iridium Bis(phosphinite) Pincer Catalyst: Scope, Selectivity and Mechanism
Authors: Yang Jian , Brookhart Maurice
Published: December 2008

A highly efficient procedure for the reduction of a broad range of alkyl halides by triethylsilane based on a cationic iridium bis(phosphinite) pincer catalyst has been discovered and developed. This reduction chemistry is chemoselective and has unique selectivities compared with conventional radical‐based processes and the aluminum trichloride/triethylsilane (AlCl3/Et3SiH) and triphenylmethyl tetrakis[pentafluorophenyl]borate/triethylsilane {[Ph3C] [B(C6F5)4]/Et3SiH} systems. Reductions use three equivalents of triethylsilane relative to the halide and can be carried out with very low catalyst loadings and in a solvent‐free manner, which may provide an environmentally attractive and safe alternative to many currently practiced methods for reduction of alkyl halides. Mechanistic studies reveal a unique catalytic cycle. The cationic iridium hydride 2,6‐bis[di‐(tert‐butyl)phosphinyloxy)phenyl(hydrido)iridium, (POCOP)IrH+ {POCOP= 2,6‐[OP(t‐Bu)2]2C6H3} binds and activates the silane. This complex serves as a potent silylating reagent to generate silyl halonium ions, Et3SiXR+, which are reduced by the neutral iridium dihydride to yield alkane product and regenerate the cationic (POCOP)IrH+, thus closing the catalytic cycle. All key intermediates have been identified by in situ NMR monitoring and kinetic studies have been completed. An application of this reduction system to the catalytic hydrodehalogenation of a metal chloride complex is also described.
Kinetic Study of the Asymmetric Hydrogenation of Methyl Acetoacetate in the Presence of a Ruthenium Binaphthophosphepine Complex
Authors: Öchsner Eva , Etzold Bastian , Junge Kathrin , Beller Matthias , Wasserscheid Peter
Published: December 2008

The asymmetric hydrogenation of methyl acetoacetate (MAA) in methanol using dibromobis{(S)‐4‐phenyl‐4,5‐dihydro‐3H‐dinaphtho[2,1‐c: 1′,2′‐e]phosphepine}‐ruthenium was studied in detail. For the determination of the reaction network, data from kinetic experiments were compared to different possible reaction networks using the kinetic software Presto Kinetics. The simulation was optimised to describe the reaction accurately with a minimal set of process parameters and reaction equations. For the best model the reaction orders, collision factors and activation energy of all reaction steps were determined. Additionally, the influence of reaction temperature and hydrogen pressure on the enantiomeric excess (ee) of the reaction was studied. It was found that high reaction temperatures and high hydrogen pressures result in increasing enantioselectivities.
A Dramatic Substituent Effect in Silver(I)‐Catalyzed Regioselective Cyclization of ortho‐Alkynylaryl Aldehyde Oxime Derivatives
Authors: Gao Hongyin , Zhang Junliang
Published: December 2008

A dramatic substituent effect was found in the silver(I)‐catalyzed cyclization reaction of ortho‐alkynylaryl aldehyde oxime derivatives. When R is an alkyl group, the Ag(I)‐catalyzed reaction in dimethylacetamide at 110 °C (conditions A) affords isoquinolines in good to excellent yields, in contrast, isoquinolin‐1(2 H)‐ones were produced in moderate to high yields under conditions B (dimethylformamide, room temperature) when R is an acetyl group. A plausible mechanism was proposed for this product selectivity control reaction (PSCR) by subtle structure modification.
Copper(II)‐Catalyzed CC Bond‐Forming Reactions of α‐Electron‐Withdrawing Group‐Substituted Ketene S,S‐Acetals with Carbonyl Compounds and a Facile Synthesis of Coumarins
Authors: Yuan Hong‐Juan , Wang Mang , Liu Ying‐Jie , Liu Qun
Published: December 2008

A new catalytic CC bond‐forming reaction has been developed. Catalyzed by cheap and commercially available copper(II) bromide (CuBr2; 10 mol%), the reactions of α‐electron‐withdrawing group (EWG)‐substituted ketene S,S‐acetals with aldehydes or ketones in acetonitrile at room temperature gave a variety of densely functionalized coupling products in excellent yields (80–98%). Based on this catalytic process, coumarin derivatives were efficiently synthesized when salicylaldehydes were selected as the carbonyl components.
Enantioselective Organocatalytic Michael Addition of α‐Substituted Cyanoacetates to α,β‐Unsaturated Selenones
Authors: Marini Francesca , Sternativo Silvia , Del Verme Francesca , Testaferri Lorenzo , Tiecco Marcello
Published: December 2008

A novel enantioselective (up to 90% ee) Michael addition of α‐substituted cyanoacetates to α,β‐unsaturated selenones in the presence of bifunctional urea and thiourea organocatalysts is described. The Michael adducts, containing an all‐carbon quaternary stereocenter, are smoothly converted into synthetically useful polyfunctional compounds by taking advantage of the excellent leaving group ability of the selenone group.
Highly Enantio‐ and Diastereoselective Inverse Electron Demand Hetero‐Diels–Alder Reaction using 2‐AlkenoylpyridineN‐Oxides asOxo‐Heterodienes
Authors: Barroso Santiago , Blay Gonzalo , Muñoz M. Carmen , Pedro José R.
Published: December 2008

A general catalytic inverse electron demand hetero‐Diels Alder reaction for 2‐alkenoylpyridineN‐oxides is presented. 2‐AlkenoylpyridineN‐oxides react very efficiently with alkenes in the presence of bisoxazolidine‐copper(II) [BOX‐Cu(II)] complexes to give chiral dihydropyrans bearing a pyridine ring at the 6‐position with very high yields and excellent diastereo‐ and enantioselectivity. These heterodienes exhibited higher reactivity and enantioselectivity than the corresponding non‐oxidized 2‐alkenoylpyridines.
Iron(III) Salt‐Catalyzed Nazarov Cyclization/Michael Addition of Pyrrole Derivatives
Authors: Fujiwara Masamune , Kawatsura Motoi , Hayase Shuichi , Nanjo Masato , Itoh Toshiyuki
Published: December 2008

The Nazarov cyclization of two types of pyrrole derivatives was effectively catalyzed by 5 mol% alumina‐supported iron(III) perchlorate [Fe(ClO4)3⋅Al2O3 ] which provided the desired cyclization with high trans selectivity in good to excellent yield. The cyclized product was next reacted with a vinyl ketone in the presence of the same iron salt to afford the corresponding Michael product. A sequential type Nazarov/Michael reaction of pyrrole derivatives has also been accomplished; the synthetic route to 4,5‐dihydrocyclopenta[b]pyrrol‐6(1 H)‐one derivative 5 or 5,6‐dihydrocyclopenta[b]pyrrol‐4(1 H)‐one derivative 6 has thus been established using a very economical iron catalyst.
Protein adsorption kinetics in charged agarose gels: Effect of agarose content and modeling
Authors: Schirmer Emily B. , Carta Giorgio
Published: December 2008

The adsorption kinetics of myoglobin in charged gels of varying agarose content have been measured macroscopically, through batch uptake experiments, and microscopically, using light microscopy with gels supported in microfluidics chips. The apparent effective pore diffusivities, determined by fitting either set of rate data to the shrinking core model, were greater than the free solution diffusivity and concentration‐dependent. Moreover, the microscopically derived concentration profiles were qualitatively different from the predicted ones. Therefore, a new model taking into account an assumed favorable partitioning of the protein in the pore liquid is proposed to describe the adsorption kinetics. The new model yields effective pore diffusivities that are in approximate agreement with the values determined chromatographically under nonbinding conditions and with hindered diffusion theory. In addition, it predicts concentration profiles in the gel that are consistent with those observed microscopically. The overall increase in mass transfer is attributed to the favorable partitioning of the protein in the pores at low ionic strength, which results in a greater diffusional driving force. © 2008 American Institute of Chemical Engineers AIChE J, 2009
Metal and solvent‐free cyanosilylation of carbonyl compounds with tris(pentafluorophenyl)borane
Authors: Kadam Santosh T. , Kim Sung Soo
Published: December 2008

A highly effective method of the cynaosilylation of aldehydes and ketones with TMSCN in the presence of catalytic amount of B(C6F5)3 [tris(pentafluorophenyl)borane] has been developed. Cyano transfer from TMSCN to carbonyl group proceeds at room temperature under solvent‐free conditions. Various alehydes and ketones have been converted into the corresponding trimethylsilylether within short reaction times with excellent yield under mild conditions. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation and permeation characterization of β‐zeolite‐incorporated composite membranes
Authors: Huang Zhen , Su Jun‐Feng , Su Xiao‐Qun , Guo Yu‐Hua , Teng Li‐Jun , Min Yang Chuan
Published: December 2008

In this work, several β‐zeolite‐incorporated polymer composite membranes were fabricated with the solution‐casting method. The zeolite loadings were 10, 20, and 30 wt %, respectively. Scanning electron microscopy characterization showed that the zeolite particles could be uniformly distributed in the whole polymer matrix. Gas permeation results demonstrated that after the incorporation of the same β‐zeolite, the polyimide exhibited a significant increase in gas permeability but a decrease in permselectivity, and both were quite pronounced at high zeolite loadings; this resulted from the loose structure that formed. The poly(ether sulfone) composite membranes showed obvious increases in both permeability and selectivity, and the permeability increase was considerably greater at higher zeolite loadings. The permselectivity increase could possibly be attributed to the pore sieving and preferential adsorption of β‐zeolite entities for the test gases as the heat treatment may have resulted in the formation of a defect‐free microstructure. However, breakthrough of the upper‐bound line was not achieved for these composite membranes, as reflected by Robeson plots. Our results suggest that changes in membrane performance not only are attributable to the properties and content of β‐zeolite particles but also depend on the heterogeneous microstructure created by zeolite entities. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of electron‐beam irradiation on ethylene–methyl acrylate copolymer
Authors: Mongal Nilambar , Chakraborty Debabrata , Bhattacharyya Rupa , Kumar Chaki Tapan , Bhattacharya Pinaki
Published: December 2008

Ethylene–methyl acrylate copolymer (Elvaloy 1330) was irradiated by an electron beam at different levels of radiation both in the presence and absence of a trimethylolpropane trimethacrylate sensitizer at various dosages of incorporation. The mechanical, thermal, and electrical properties of these samples were compared. The mechanical properties were observed to reach an optimum maximum around 6 Mrad of irradiation and 1 phr of sensitizer incorporation. Furthermore, an increase in either the radiation dose or the sensitizer level helped very little to further modify the properties. The thermal properties as determined by the thermogravimetric analysis and differential scanning calorimetry studies were quite supportive of the observation made during the study of the mechanical properties. The thermal stability of the irradiated samples underwent an increase with increasing electron‐beam dosage. In a manner similar to those of the mechanical properties, the increase in thermal stability was found to reach a maximum at a particular level of treatment and sensitizer incorporation, beyond which there was marginal or no effect at all. The α transition temperature underwent a substantial increase with increasing crosslink density, as evidenced by the increase in gel content with increasing proportion of electron‐beam radiation dose. The other glass‐transition temperature, however, appeared to remain unaffected. The electrical properties, as described by the dielectric constant, volume resistivity, and breakdown voltage, appeared to be affected very little by the electron‐beam radiation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Functionalization via glycerol transesterification of polymerized soybean oil
Authors: Lubguban Arnold A. , Tu Yuan‐Chan , Lozada Zuleica R. , Hsieh Fu‐Hung , Suppes Galen J.
Published: December 2008

An acylglycerol‐based molecule was synthesized by the thermal polymerization (bodying) of soybean oil followed by transesterification with glycerol. Transesterification with glycerol at temperatures greater than 200°C provided the desired polyol prepolymers. The extent of bodying and quantity of glycerol added during the transesterification provided tunability of the polyol molecular weight and functionality. The hydroxyl numbers, acidity, and viscosity of the polyols were characterized. The polyols were evaluated in elastomers and rigid foams. Extractability analyses were performed on the polyurethane elastomer wafers to evaluate crosslinking. Rigid foaming results for the processed soy‐based polyol showed excellent physicochemical properties suggesting comparability with a petroleum‐based polyether polyol. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Flame‐retardant properties of magnesium hydroxystannate and strontium hydroxystannate coated calcium carbonate on soft poly(vinyl chloride)
Authors: Jiao Yunhong , Xu Jian Zhong
Published: December 2008

The flame‐retardant and smoke‐suppressant properties of soft poly(vinyl chloride) (PVC) treated with zinc hydroxystannate (ZHS), calcium carbonate (CaCO3), magnesium hydroxystannate [MgSn(OH)6], strontium hydroxystannate [SrSn(OH)6], ZHS–MgSn(OH)6, ZHS–SrSn(OH)6, MgSn(OH)6‐coated CaCO3, SrSn(OH)6‐coated CaCO3, ZHS–MgSn(OH)6‐coated CaCO3, and ZHS–SrSn(OH)6‐coated CaCO3 were studied with the limited oxygen index, char yield, and smoke density rating methods; the mechanical properties were also studied. The results showed that, with the equivalent addition of the corresponding hydroxystannate, the soft PVC treated with hydroxystannate‐coated CaCO3 had a higher limited oxygen index than the corresponding hydroxystannate, and the soft PVC treated with the agents containing magnesium had a higher limited oxygen index than the soft PVC treated with the agents containing strontium, except for ZHS–MgSn(OH)6‐coated CaCO3. The improvement in the char formation of the hydroxystannate‐coated CaCO3 was better than that of the corresponding hydroxystannate in most cases, and the aforementioned agents reduced the smoke density rating, decreased the tensile strength, and increased the elongation and impact strength basically. Thermal analysis showed that the additives promoted the evolution of hydrogen chloride, early crosslinking, and rapid charring through the strong catalyzing effect of Lewis acids. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of the nature and combinations of solvents in the intercalation of clay with block copolymers on the properties of polymer nanocomposites
Authors: Şen Sinan , Nugay Nihan , Nugay Turgut
Published: December 2008

Polystyrene (PS) nanocomposites were prepared by the free‐radical polymerization of styrene in the presence of organically modified montmorillonite (MMT) clays. MMT clay was modified with a low‐molecular‐weight and quarternized block copolymer of styrene and 4‐vinylpyridine [poly(styrene‐b‐4‐vinylpyridine) (SVP)] with 36.4 wt % PS and 63.6 wt % poly(4‐vinylpyridine) (P4VP). Special attention was paid to the modification, which was carried out in different compositions of a solvent mixture of tetrahydrofuran (THF) and water. The swelling behavior of the MMT clay was studied by an X‐ray diffraction technique. The diffraction peak shifted to lower 2θ angles for all of the modified clays, which indicated the intercalation of the quarternized SVP copolymer into the MMT layers in different degrees. Higher interlayer distances, which showed a high degree of block copolymer insertion, were obtained for solvent compositions with THF in water. The resultant nanocomposites were characterized by X‐ray diffraction, atomic force microscopy, scanning electron microscopy, thermogravimetric analysis, and dynamic mechanical analysis. The desired exfoliated nanocomposite structure was achieved when the MMT modification was conducted in 50 or 66 wt % THF, whereas the other modifications all resulted in intercalated structures. The resulting exfoliated nanocomposite was found to have better thermal stability and dynamic mechanical performance compared to the others, even with 2% clay loading. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Design engineers and technical professionals at work: Observing information usage in the workplace
Authors: Allard Suzie , Levine Kenneth J. , Tenopir Carol
Published: December 2008

This exploratory study examines how design engineers and technical professionals (hereafter referred to as engineers) in innovative high‐tech firms in the United States and India use information in their daily work activities including research, development, and management. The researchers used naturalistic observation to conduct a series of daylong workplace observations with 103 engineers engaged in product design and testing in four U.S.‐ and two India‐based firms. A key finding is that engineers spend about one fourth of their day engaged in some type of information event, which was somewhat lower than the percentage identified in previous research. The explanation may be rooted in the significant change in the information environment and corporate expectations in the last 15 years, which is the time of the original study. Searching technology has improved, making searching less time consuming, and engineers are choosing the Internet as a primary source even though information may not be as focused, as timely, or as authoritative. The study extends our understanding of the engineering workplace, and the information environment in the workplace, and provides information useful for improving methods for accessing and using information, which could ultimately lead to better job performance, facilitate innovation, and encourage economic growth.
Chiral Guanidine Catalyzed Enantioselective Reactions
Authors: Leow Dasheng , Tan Choon‐Hong
Published: December 2008

Pinches like a crab: The utilization of guanidines as catalysts has been growing at a steady pace. They possess high pKa values and activate through dual hydrogen‐bonding modes of activation. This Focus Review highlights the development of chiral guanidine catalysts in asymmetric organic transformations.

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Chiral guanidine catalysts share common characteristics such as high pKa values and dual hydrogen‐bonding modes of activation, and high catalytic activities and enantioselectivities can often be achieved. The utilization of guanidines as catalysts has been growing at a steady pace. In the past few years, it has attracted tremendous attention through several landmark achievements. This article highlights the development of chiral guanidine catalysis in asymmetric synthesis.
Transition‐Metal‐Catalyzed Enantioselective [2+2+2] Cycloadditions for the Synthesis of Axially Chiral Biaryls
Authors: Tanaka Ken
Published: December 2008

Tying up loose ends: Recent advances towards a development of novel transition‐metal‐catalyzed enantioselective [2+2+2] cycloadditions for the synthesis of biaryls are summarized in this Focus Review. Additionally, the enantioselective synthesis of axially chiral biaryls possessing non‐biaryl axial chirality is also presented. These novel asymmetric aromatization reactions allow the production of various axially chiral biaryl compounds with high enantioselectivity.

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Recent advances towards a development of novel transition‐metal‐catalyzed enantioselective [2+2+2] cycloadditions for the synthesis of axially chiral biaryls are reviewed. A number of efficient enantioselective biaryl syntheses were accomplished by chiral cobalt(I), iridium(I), and rhodium(I) complex catalyzed [2+2+2] cycloadditions. Furthermore, the enantioselective synthesis of axially chiral biaryls possessing non‐biaryl axial chirality was also developed by using chiral rhodium(I) complexes as catalysts.
First passage time for multivariate jump‐diffusion processes in finance and other areas of applications
Authors: Zhang Di , Melnik Roderick V. N.
Published: December 2008

The first passage time (FPT) problem is an important problem with a wide range of applications in science, engineering, economics, and industry. Mathematically, such a problem can be reduced to estimating the probability of a stochastic process first to reach a boundary level. In most important applications in the financial industry, the FPT problem does not have an analytical solution and the development of efficient numerical methods becomes the only practical avenue for its solution. Most of our examples in this contribution are centered around the evaluation of default correlations in credit risk analysis, where we are concerned with the joint defaults of several correlated firms, the task that is reducible to a FPT problem. This task represents a great challenge for jump‐diffusion processes (JDP). In this contribution, we develop further our previous fast Monte Carlo method in the case of multivariate (and correlated) JDP. This generalization allows us, among other things, to evaluate the default events of several correlated assets based on a set of empirical data. The developed technique is an efficient tool for a number of financial, economic, and business applications, such as credit analysis, barrier option pricing, macroeconomic dynamics, and the evaluation of risk, as well as for a number of other areas of applications in science and engineering, where the FPT problem arises. Copyright © 2008 John Wiley & Sons, Ltd.
The dynamics of the relationship between spot and futures markets under high and low variance regimes
Authors: Li Ming‐Yuan Leon
Published: December 2008

This investigation is one of the first studies to examine the dynamics of the relationship between spot and futures markets using the Markov‐switching vector error correction model. Three mature stock markets including the U.S. S&P500, the U.K. FTSE100 and the German DAX 30, and two emerging markets including the Brazil Bovespa and the Hungary BSI, are used to test the model, and the differences between the two sets of markets are examined. The empirical findings of this study are consistent with the following notions. First, after filtering out the high variance regime, the futures price is shown to lead the spot price in the price discovery process, as demonstrated by prior studies; conversely, the spot market is more informationally efficient than the futures market under the high variance condition. Second, the price adjustment process triggered by arbitrage trading between spot and futures markets during a high variance state is greater in scale than that based on a low variance state, and the degree of the co‐movement between spot and futures markets is significantly reduced during the high variance state. Third, a crisis condition involved in the high variance state is defined for the two emerging markets, whereas an unusual condition is presented for the three mature markets. Last, the lagged spot–futures price deviations perform as an information variable for the variance‐turning process. However, the portion of the variance‐switching process accounted for by this signal variable is statistically marginal for the three mature markets selected for this study. Copyright © 2008 John Wiley & Sons, Ltd.
Glutathione peroxidase mimics as novel antioxidants from vegetables
Authors: Terao Junji , Hiwada Mio , Taguchi Keiko , Takahara Keigo , Mohri Satoshi
Published: December 2008

Vegetables are generally recognized as rich sources of dietary antioxidants for inhibiting lipid peroxidation. Here we investigated lipid hydroperoxide (LOOH)‐reducing activity of several vegetables to estimate their role on the prevention of lipid peroxidation in food and the digestive tract. By using HPLC analysis, we screened vegetables possessing the ability to convert 13‐hydroperoxyoctadecadienoic acid (13‐HPODE) to its reduced derivative, 13‐hydroxyoctadecadienoic acid (13‐HODE). Welsh onion (Allium fistulosum L.) was found to be highly active in the reduction of 13‐HPODE among tested vegetables. There was no relationship between 13‐HPODE reducing activity and GSH peroxidase (GPX) activity in the tested vegetables. 13‐HPODE‐reducing activity of welsh onion was enhanced by the addition of sulfhydryl compounds including glutathione (GSH). Neither GPX inhibitor nor heat treatment suppressed 13‐HPODE‐reducing activity effectively. These results suggest that welsh onion and other vegetables contain GPX mimics responsible for the reduction of LOOH. GPX mimics may be helpful in the attenuation of harmful effect of LOOH from food.
Treatment of massive hypertriglyceridemia resistant to PUFA and fibrates: A possible role for the coenzyme Q10?
Authors: Cicero A.F.G. , Derosa G. , Miconi A. , Laghi L. , Nascetti S. , Gaddi A.
Published: December 2008

Objective: to describe the effect of CoQ10 (added to either a fibrate, or PUFA or association of both) in patients affected by massive hypertriglyceridemia (MHTG) resistant to fibrates and PUFA.

Design: Open, sequential, comparative intervention study. Setting: Specialised centres for dyslipidemia management.

Subjects: 15 subjects (mean age: 45.1 ± 12.5 years) affected by MHTG and hyporesponsive to either fibrates, or PUFA, or fibrates‐PUFA association, and 15 age‐matched subjects regularly responders to PUFA and fenofibrate treatment.

Interventions: Treatment for periods of 6 weeks each with the following consecutive treatments: CoQ10 150 mg/day, PUFA 3000 mg/day, fenofibrate 200 mg/day, PUFA 3000 mg/day + fenofibrate 200 mg/day, PUFA 3000 mg/day + CoQ10 150 mg/day, fenofibrate 200 mg/day + CoQ10 150 mg/day, and finally, fenofibrate 200 mg/day + PUFA 3000 mg/day + CoQ10 150 mg/day.

Results: CoQ10 supplementation improved, in the control group, systolic and diastolic blood pressure, creatinine and Lp(a) plasma levels, both during fenofibrate and/or PUFA treatment. In MHTG group, CoQ10 supplementation significantly improved TG, TC, Lp(a), uric acid and blood pressure during fenofibrate treatment, but only Lp(a) and blood pressure during PUFA treatment. Fenofibrate appeared to have better effect on hsCRP and γ‐GT plasma levels than PUFA. No significant change was observed in any group and under any treatment in regards to homocysteinemia, PAI‐1, or t‐PA.

Conclusion: Even though the mechanism of action through which the effects were obtained is yet to be elucidated, adding CoQ10 to fenofibrate could improve the drug's efficacy in MHTG patients not responding to fenofibrate alone.
Minoxidil, a KATPchannel opener, accelerates DNA synthesis following partial hepatectomy in rats
Authors: Yamasaki Keiichi , Takemura Shigekazu , Minamiyama Yukiko , Hai Seikan , Yamamoto Satoshi , Kodai Shintaro , Hirohashi Kazuhiro , Suehiro Shigefumi
Published: December 2008

A large number of studies have reported the action of KATPchannel openers in accelerating the proliferation of hepatocytes and many other cell typesin vitro. Few studies, however, have examined the proliferative effect of KATPchannel openersin vivo. The aim of this study was to determine whether the KATPchannel opener minoxidil accelerates liver regeneration after partial hepatectomy (PH)in vivo. Male Wistar rats underwent a 70% partial hepatectomy (PH) after receiving a subcutaneous injection of minoxidil (0.01 mg/kg or 0.03 mg/kg). Some of the rats were intravenously treated with 5‐hydroxydecanoic acid (5‐HD, 10 mg/kg) just before the minoxidil injection. Seventy‐two hours after PH, DNA synthesis was immunohistochemically assessed by bromodeoxyuridine (BrdU) incorporation into the nuclei. Minoxidil induced significant and dose‐dependent increase in the BrdU labeling index after PH, and 5‐HD reversed this minoxidil‐induced change. Minoxidil did not significantly affect the changes in liver weight and liver function after PH. The hepatic levels of prealbumin decreased by about 60% after PH and minoxidil inhibited the decrease. In conclusion, the KATPchannel opener minoxidil enhanced DNA synthesis after PH without affecting the liver function.
EGCG, a major component of green tea, inhibits VEGF production by swine granulosa cells
Authors: Basini Giuseppina , Bianco Federico , Grasselli Francesca
Published: December 2008

Vascular Endothelial Growth Factor (VEGF) plays a pivotal role in the physiological ovarian angiogenic process: its production appears to be stimulated by the hypoxic environment which takes place during follicle development. Recently, epigallocatechin‐3‐gallate (EGCG) from green tea has been used in livestock nutrition as an alternative to antibiotics. However, despite many potential benefits of EGCG consumption, it is also important to get an insight on the possible reproductive‐related consequences of feeding supplementation: in fact this substance has been found to inhibit angiogenesis, a process fundamental for follicle development. Therefore, we evaluated the effect of EGCG (5 and 50 μ/ml) on the production of the main angiogenetic factor, VEGF, by swine granulosa cells cultured in normoxia (19% O2), partial (5% O2) or total hypoxia (1% O2). In addition, we studied the effect of the catechin on cell proliferation. Our data demontrate that both partial and total hypoxia stimulated VEGF production. EGCG reduced VEGF production independently of the O2 condition: 50 μM was the most effective doses. Granulosa cell proliferation was inhibited by EGCG even if only by the highest concentration. This effect might possibly be due to the decrease induced in VEGF production. Therefore feeding supplementation with EGCG should be carefully considered.
Lipid peroxidation in plasma of rats treated with ferric‐nitrilotriacetate, in relation to kidney and liver modifications
Authors: Deiana Monica , Rosa Antonella , Corona Giulia , Collu Stefania , Ennas Maria Grazia , Dessì Maria Assunta
Published: December 2008

Intraperitoneal injection of the iron chelate ferric‐nitrilotriacetate (Fe‐NTA) induces in rodents renal and hepatic suffering, associated with oxidative damage. We investigated the oxidation pattern in plasma of treated rats in relation to liver and kidney, monitoring the variation of the lipid components more susceptible to oxidation, unsaturated fatty acids (UFA) and α‐tocopherol, as biomarkers of the oxidative damage. A sublethal dose of Fe‐NTA induced a strong and extremely significant decrease of UFA levels at 1 h after injection in the plasma compartment and at 3 h in the kidney, with reductions up to 40–50% of the control values, together with an increase of conjugated dienes fatty acids hydroperoxides and a consumption of α‐tocopherol. The same modifications were observed in the liver, but to a lesser extent. Histological observation proved that biochemical changes in the lipid fraction were a direct consequence of an ongoing membrane lipid peroxidation process. Our data show that oxidative damage to the lipid fraction is initially evident in the plasma compartment, where Fe‐NTA toxicity is assumed to be caused by the elevation of serum free iron concentration, and proceeds with different speed and severity in the kidney and liver.
Genomics of berry fruits antioxidant components
Authors: D'Amico E. , Perrotta G.
Published: December 2008

Reactive oxygen and nitrogen metabolites, which are side products of cell metabolism, can produce a lot of damage in biological macromolecules and tissues, producing a number of chronic illnesses. On the other hand, antioxidant metabolites usually accumulated in fruits and vegetables can provide an effective protection by neutralizing these reactive molecules.

Among comestible vegetables, berry fruits are considered one of the richest sources of antioxidant metabolites; hence, they represent a good model for molecular and biochemical investigations about the biosynthesis and the functional role of antioxidants in plants. This review illustrates how recent developments in the fields of genomics and bioinformatics can provide powerful tools to better understand the molecular mechanisms that trigger biosynthesis and accumulation of antioxidant metabolites in berries.
The inhibitory effects of berry polyphenols on digestive enzymes
Authors: Mcdougall Gordon J. , Stewart Derek
Published: December 2008

The evidence for the effect of polyphenol components of berries on digestive enzymes is reviewed. Anthocyanins inhibit α‐glucosidase activity and can reduce blood glucose levels after starch‐rich meals, a proven clinical therapy for controlling type II diabetes. Ellagitannins inhibit α‐amylase activity and there is potential for synergistic effects on starch degradation after ingestion of berries such as raspberries and strawberries, which contain substantial amounts of ellagitannins and anthocyanins.

A range of berry polyphenols (e.g. flavonols, anthocyanidins, ellagitannins and proanthocyanidins) can inhibit protease activities at levels which could affect protein digestion in the gastrointestinal tract. In contrast, potential for the inhibition of gastrointestinal lipase activity, a proven therapeutic target for the control of obesity through reduced fat digestion, may be limited to proanthocyanidins.

Taking into account the manifold possible synergies for inhibition of starch, protein and/or lipid digestion by the spectrum of polyphenol components present within berry species, the inhibition of digestive enzymes by dietary polyphenols may represent an under‐reported mechanism for delivering some of the health benefits attributed to a diet rich in fruit and vegetables.
Identification and dietary relevance of antioxidants from raspberry
Authors: Beekwilder Jules , Hall Robert D. , Ric Vos C.H. De
Published: December 2008

In this paper we review the current literature on antioxidants from fruit of red raspberry (Rubus idaeus) and place these in context concerning what is known from other food species. The review concentrates on the methods of antioxidant testing, the diversity of antioxidants in raspberry, effects of ripeness, cultivar, storage and processing techniques, and the bioavailability of raspberry antioxidants in humans after eating the fruit. It is clear that raspberry, like several other fruits and vegetables such as tomato, strawberry, kiwi and broccoli, represents a valuable contrasting source of potentially healthy compounds and can represent an important component of a balanced diet.