bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuroprotective effect of nicardipine on cadmium‐induced Purkinje cell death in rat cerebellum
Authors: Bağirici Faruk , Genç Hayri , Tan Faruk , Demir Şerif
Published: August 2002

The present study was designed to investigate the effects of nicardipine on cadmium‐induced Purkinje cell loss in cerebellum of rats. Animals were divided into three groups as control, cadmium and cadmium + nicardipine groups. Saline, cadmium sulphate (0,0021 mg/kg) and cadmium sulphate (0,0021 mg/kg) + nicardipine (1 mg/kg) were intracortically administered respectively. All rats were observed for one week, but only the rats in the third group were injected nicardipine (10 mg/kg/day, i.p.) during this period. One week later, all rats were perfused intracardially. Series of frontal sections from cerebella were stained with Thionin staining. Purkinje cells were counted under ×400 magnification via a light microscope

Cadmium administration caused 25–35 % decrease in Purkinje cell density in Crus I, Crus II and Lobulus Simplex areas of cerebellum in cadmium group (p<0.05). The Purkinje cell density was 16–23 % less in nicardipine‐treated group than control and cells were partially protected from toxic effects of cadmium significantly (p<0.05).

These results suggest that cadmium has neurotoxic effects on Purkinje cells in cerebellum and nicardipine may protect neurons from cadmium‐induced toxicity (p<0.05).
Implicit kinetic schemes for scalar conservation laws
Authors: Botchorishvili Ramaz
Published: August 2002

Based on kinetic formulation for scalar conservation laws, we present implicit kinetic schemes. For time stepping these schemes require resolution of linear systems of algebraic equations. The scheme is conservative at steady states. We prove that if time marching procedure converges to some steady state solution, then the implicit kinetic scheme converges to some entropy steady state solution. We give sufficient condition of the convergence of time marching procedure. For scalar conservation laws with a stiff source term we construct a stiff numerical scheme with discontinuous artificial viscosity coefficients that ensure the scheme to be equilibrium conserving. We couple the developed implicit approach with the stiff space discretization, thus providing improved stability and equilibrium conservation property in the resulting scheme. Numerical results demonstrate high computational capabilities (stability for large CFL numbers, fast convergence, accuracy) of the developed implicit approach. © 2002 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 18: 26–43, 2002
Marine resources from an urban Moche (470–600 ad) area in the ‘Huacas del Sol y de la Luna’ archaeological complex (Trujillo, Peru)
Authors: Roselló E. , Vásquez V. , Morales A. , Rosales T.
Published: August 2002

An analysis of the marine animal remains retrieved in a sector of Huacas de Moche archaeological complex is presented. The area,14C‐dated between 470 and 600 ad (Moche IV/V), includes a poorly diversified fauna with two dominating species (donax clam and hake) despite the large number of secondary taxa (71). Such faunal spectrum corresponds to a secondary type of cropping strategy, likely to go through some kind of cultural filter (market), thus indirectly certifying the social complexity of Moche urban centres in general and the centralized and redistributive nature of Moche economy in particular. From an environmental standpoint most of the taxa indicate ‘normal’ (i.e. non‐El Niño–Southern Oscillation (ENSO)) conditions and their abundance and ecological affinities correspond to what one could expect to find at present on the shores of the Moche Valley. The fish assemblage, moreover, suggests the existence of a low status population whereas complementary data indicate that a few of the taxa might not have had exclusively dietary connotations. Copyright © 2001 John Wiley & Sons, Ltd.
Polymer bound glutamic acid salicylaldehyde Schiff‐base complex ­catalyst for oxidation of olefins with ­dioxygen
Authors: Wang Rong‐Min , Hao Cheng‐Jun , He Yu‐Feng , Wang Yun‐Pu , Xia Chun‐Gu
Published: August 2002

The polymer bound Schiff‐base ligand (PS‐SalGlu) has been prepared from polystyrene bound salicylaldehyde and glutamic acid, and its complex (PS‐SalGlu‐Co) has also been synthesized. The polymer ligand and its complex were characterized by infrared spectroscopy, small area X‐ray photoelectron spectroscopy, and inductively coupled plasma‐atomic emission spectro (ICP‐AFS). In the presence of the complex, cyclohexene can be effectively oxidized by molecular oxygen without reductant. The long‐chain linear aliphatic olefins, such as 1‐octene, 1‐decene, 1‐dodecene and 1‐tetradecene, can be directly oxidized by molecular oxygen catalyzed by PS‐SalGlu‐Co, which affords the 1,2‐epoxy alkane. Copyright © 2001 John Wiley & Sons, Ltd.
Liquid chromatography–Atmospheric pressure chemical ionisation/Mass spectrometry: a rapid and selective method for the quantitative determination of ginkgolides and bilobalide in ginkgo leaf extracts and phytopharmaceuticals
Authors: Jensen Anette Gemal , Ndjoko Karine , Wolfender Jean‐Luc , Hostettmann Kurt , Camponovo Fabrizio , Soldati Fabio
Published: August 2002

In order to evaluate the composition of active constituents in phytopharmaceutical preparations, valid analytical methods are required. For the determination of the active terpene constituents of Ginkgo biloba (the ginkgolides and bilobalide), a liquid chromatography–mass spectrometry (LC‐MS) method has been developed using atmospheric pressure chemical ionisation (APCI) in the negative ion mode. This detection mode was found to be much more sensitive and selective compared to UV; indeed the ginkgo terpene trilactones lack strong UV chromophores and flavonoids interfere with their UV detection. LC‐APCI/MS detection allowed a considerable reduction in analysis time when compared to LC‐UV, because LC resolution was only needed between the pair of isomers ginkgolide B and ginkgolide J. All compounds were selectively detected by single ion monitoring of their specific deprotonated molecules [M‐H]−. The samples were directly injected without pre‐purification, and a fast gradient was applied, reducing the total time of analysis to 14 min. With this method, the ginkgo terpene trilactones were detected on‐line in the picogram range. Several commercial ginkgo preparations on the Swiss market were analysed, and the ginkgolide and bilobalide contents were evaluated using the method described. Copyright © 2001 John Wiley & Sons, Ltd.
Reliability of prenatal sonographic lung biometry in the diagnosis of pulmonary hypoplasia
Authors: Heling Kai‐Sven , Tennstedt Cornelia , Chaoui Rabih , Kalache Karim D. , Hartung John , Bollmann Rainer
Published: August 2002

Objective

The purpose of the present study was to assess the value of biometric lung measurements for the diagnosis of severe fetal pulmonary hypoplasia by investigating whether a significant correlation between two‐dimensional lung biometry measurements and autopsy findings could be established.

Methods

This was a prospective study carried out between 1995 and 1997. Nomograms for normal fetuses of the arterior–posterior and transverse inner thoracic diameters, which describe the growth and shape of the lung, were used as a basis for diagnosis of pulmonary hypoplasia in fetuses at high risk of developing the condition (the fetuses had bilateral renal agenesis or multicystic kidneys; chronic PROM <25 gestational weeks or hydrothorax). Pregnancy was terminated by abortion or intrauterine death in 29/43 high‐risk fetuses and autopsies were performed. Only the 29 fetuses for which there were autopsy findings were included in the study.

Results

The best plane for diagnosing pulmonary hypoplasia was the four‐chamber view. The diagnostic accuracy for this view as expressed by the sensitivity was 57% for the anterior–posterior diameter and 44% for the transverse diameter; as expressed by the specificity it was 42% for the anterior–posterior diameter and 50% for the transverse diameter. The results for the four‐chamber view for the various high‐risk conditions were as follows: for fetuses with chronic PROM we obtained sensitivities of 75% and 50% (anterior–posterior and transverse dimensions, respectively) and specificities of 80% and 60% (anterior–posterior and transverse dimensions, respectively). The sensitivities of lung biometry in fetuses with hydrothorax were 1% and 80% for the two diameters, but there was a low specificity. In fetuses with bilateral renal agenesis or multicystic kidneys we obtained sensitivities of 36% and 30% (anterior–posterior and transverse dimensions, respectively) and a specificity of 50% (anterior–posterior dimension).

Conclusions

The pesent results show that two‐dimensional lung biometry is not a suitable method for antenatal detection of pulmonary hypoplasia. However, in individual cases with high risk for pulmonary hypoplasia, lung biometry might prove to be an additional diagnostic parameter. Copyright © 2001 John Wiley & Sons, Ltd.
Prenatal diagnosis of a homologous Robertsonian translocation involving chromosome 15
Authors: Abrams Debra J. , Aronoff Amy R. , Ann Berend Sue , Roa Benjamin B. , Shaffer Lisa G. , Geier Mark R.
Published: August 2002

We report the prenatal diagnosis of a fetus with a de novo Robertsonian translocation: 45,XY,der(15;15)(q10;q10). Although Robertsonian translocations are common chromosomal rearrangements, those involving homologous chromosomes are infrequent. Since chromosome 15 is imprinted, uniparental disomy (UPD) is a concern when chromosomal rearrangements involving chromosome 15 are identified. In the present case, UPD studies showed normal biparental inheritance. In contrast to the fact that most homologous acrocentric rearrangements are isochromosomes, these results indicate postzygotic formation of a Robertsonian translocation between biparentally inherited chromosomes 15. Copyright © 2001 John Wiley & Sons, Ltd.
Clinical outcome of treatment cycles using preimplantation genetic diagnosis for structural chromosomal abnormalities
Authors: Fridström Margareta , Ährlund‐Richter Lars , Iwarsson Erik , Malmgren Helena , Inzunza José , Rosenlund Björn , Sjöblom Peter , Nordenskjöld Magnus , Blennow Elisabeth , Hovatta Outi
Published: August 2002

Objectives

To explore oocyte recovery, embryo quality, the number of transferable embryos and pregnancy rate after preimplantation genetic diagnosis (PGD) in patients with structural chromosomal aberrations.

Methods

PGD was performed in seven couples with Robertsonian translocations (Rob), eight couples with reciprocal translocations (Rec), two couples with inversions and one couple with a deletion. A total of 43 treatment cycles were carried out.

Results

A total of 14.2 oocytes per cycle were retrieved. Fertilisation and cleavage rates were 63% and 58%, respectively. Of the biopsied embryos 20% were transferable. Comparison of the Rob and Rec group revealed no significant differences in number of oocytes, fertilisation or cleavage rates. The number of transferable embryos after biopsy was significantly higher in the Rob group than in the Rec group. When embryo transfer (ET) was performed the pregnancy rate did not differ between the Rob and the Rec groups. Twenty‐eight embryo transfers (one or two embryos) were carried out leading to eight clinical pregnancies (29% per ET): two twins, four singletons, one miscarriage and one ectopic pregnancy. All the children are carriers of balanced chromosomal aberrations.

Conclusion

An acceptable pregnancy rate can be achieved among couples with structural chromosomal abnormalities. Copyright © 2001 John Wiley & Sons, Ltd.
Heterogeneity in fetal akinesia deformation sequence (FADS): autopsy confirmation in three 20–21‐week fetuses
Authors: Yfantis H. , Nonaka D. , Castellani R. , Harman C. , Sun C.‐C.
Published: August 2002

Fetal akinesia deformation sequence (FADS) is a rare condition characterized by intrauterine growth retardation (IUGR), congenital limb contractures, pulmonary hypoplasia, hydramnios and craniofacial abnormalities. The present report comprises an autopsy study of three fetuses to illustrate the variable clinical manifestations and neuropathological findings. Fetus 1 had arthrogryposis and no movement on fetal ultrasound examination. Aborted at 21 weeks, the fetus showed micrognathia, bilateral joint contracture with pterygia at the elbow and axilla. Growth retardation and pulmonary hypoplasia were not major features. Neuropathologic examination revealed anterior horn cell loss and lateral corticospinal tract degeneration in spinal cord, with marked muscular atrophy. Fetus 2, 20 weeks' gestation, had fetal akinesia, nuchal thickening, left pleural effusion, and Dandy‐Walker malformation on ultrasound examination. Autopsy showed low‐set ears, ocular hypertelorism, cleft palate, flexion contractures with pterygia over axilla, elbow and groin, pulmonary hypoplasia, Dandy‐Walker malformation, unremarkable spinal cord and skeletal muscle. Fetus 3, 21 weeks' gestation, was aborted for fetal akinesia, neck and limb webbing and severe arthrogryposis. At autopsy, similar facial abnormalities, contracture and pterygia in neck and multiple major joints were found. Borderline pulmonary hypoplasia and severe lumbar scoliosis were also present. The brain, spinal cord and muscle were unremarkable.

In these three fetuses, the prenatal ultrasound and autopsy findings were characteristic of FADS. Neurogenic spinal muscular atrophy was the basis of fetal akinesia in Case 1. Dandy‐Walker malformation was present in Case 2, but the pathogenetic mechanism of fetal akinesia was not clear as spinal cord and muscle histology appeared normal. The etiology of akinesia was undetermined in Case 3; no extrinsic or intrinsic cause was identified. Copyright © 2002 John Wiley & Sons, Ltd.
Accuracy of Down syndrome risks produced in a first‐trimester screening programme incorporating fetal nuchal translucency thickness and maternal serum biochemistry
Authors: Spencer Kevin
Published: August 2002

Over the past three years approximately 12 000 women have been screened in the first trimester through our OSCAR programme, which utilizes fetal NT and maternal serum free β‐hCG and PAPP‐A. During this time 30 cases of Down syndrome were identified either prenatally or postnatally. Using an established procedure the accuracy of predicted risk for Down syndrome was assessed in a population of 30 cases of Down syndrome and 11 758 unaffected pregnancies. The correlation between predicted risk and prevalence of Down syndrome was very high (r=0.9995). It is concluded that risks produced by the Fetal Medicine Foundation combined risk algorithm agree very closely with Down syndrome prevalence and can be used with confidence when counselling women of their risk. Copyright © 2002 John Wiley & Sons, Ltd.
Prenatal diagnosis of congenital nephrosis by in utero kidney biopsy
Authors: Wapner Ronald J. , Jenkins Thomas M. , Silverman Neil , Kaufmann Marion , Hannau Cheryl , McCue Peter
Published: August 2002

The diagnosis of congenital nephrosis is difficult during the antepartum period. The combination of an elevated amniotic fluid alpha‐fetoprotein, a negative acetylcholinesterase, and a negative ultrasound examination is highly indicative of congenital nephrosis; however, these findings can also be associated with a normal gestation. This is the first report of pathologic confirmation of congenital nephrosis from an in utero fetal kidney biopsy. Copyright © 2001 John Wiley & Sons, Ltd.
Prenatal detection of free sialic acid storage disease: genetic and biochemical studies in nine families
Authors: Salomäki Pirjo , Aula Nina , Juvonen Vesa , Renlund Martin , Aula Pertti
Published: August 2002

Sialic acid storage disorders, Salla disease (SD) and a severe infantile form of disease (ISSD), are recessively inherited allelic lysosomal storage disorders due to impaired egress of free sialic acid from lysosomes. Fourteen pregnancies at risk of adult‐type free sialic acid storage disease, SD, were monitored by sialic acid assays, genetic linkage or mutation detection analyses using chorionic villus samples. Three affected and 12 unaffected fetuses were identified. The first studies were based on the sialic acid assays alone, but the location of the gene enabled the use of genetic linkage analysis and, more recently, the identification of the SLC17A5 gene and disease‐causing mutations added yet another possibility for prenatal studies. A missense mutation 115C→T (R39C) is present in 95% of all Finnish SD alleles, providing an easy and reliable means of diagnostic studies. Both molecular and biochemical (sialic acid assay) studies can be used for prenatal diagnosis of free sialic acid storage diseases. Copyright © 2001 John Wiley & Sons, Ltd.
Caribbean people's health beliefs about the body and their implications for diabetes management: a South London study
Authors: Scott Penelope
Published: August 2002

This article presents the findings of a study into Caribbean people's health beliefs about the body and their body related health practices in diabetes management. The study used quantitative and qualitative methods to explore these beliefs and practices, as well as those relating to food and eating and health and disease, among 80 people with diabetes and 80 people who did not have the disease. The findings showed that the sample had distinctive beliefs about blood and having ‘washouts’, i.e. taking laxatives, and some also observed fasts for various reasons. As regards weight management, having a ‘normal’ BMI was associated with health and attractiveness and there was no evidence that being large in size was culturally valued. The vast majority were unaware, however, of the relationship between obesity and the potential onset of diabetes. The implications of these health beliefs and practices for patient education are also discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Impact of diabetes mellitus on Sudanese women
Authors: Mohamed Ahmed Awad , Hussein Abashar , Mohamed Kheir Musa , Hassan Ahmed Nada
Published: August 2002

As there are increasing numbers of Sudanese women with diabetes, there is a great need for investigating the gender‐specific factors in presentation or management of this disease. We studied 150 diabetic non‐pregnant women who attended a medical clinic in Khartoum in July 1999–January 2000. The mean age was 45.3 years, 126 (84%) had type 2 diabetes, the mean duration of diabetes was 7.3 years, 58.6% of patients were poorly controlled and there was a lack of diabetic knowledge among them. Our patients were of poor physical activity, and 28% of them were obese. They were poorly adherent to diet or treatment. The patients were, generally, illiterate (58.6%) and lacking professional skills (78.7%), and 38% were unmarried or divorced. Our patients reported marital and sexual problems, poor performance at home or work and lack of family support. The young patients were worried about their academic achievement and chances of marriage. Our diabetic women, in our society, suffer a gender‐related impact of diabetes in addition to the disease itself. Management protocols tailored for diabetic women are needed. Copyright © 2001 John Wiley & Sons, Ltd.
Changes in the care of the diabetic foot: part one
Authors: Foster A
Published: August 2002

Keypoints

The diabetic foot remains an enormous public health problem despite modern advances in foot care.

There is a lack of evidence for many diabetic foot interventions: however, there is consensus between experts that a multi‐disciplinary spproach helps reduce amputations.

Diabetic amputations are on the increase.

Copyright © 2001 John Wiley & Sons, Ltd.
Does opportunistic screening for diabetic retinopathy result in timely and appropriate referral?
Authors: Prasad S. , Jones W.A. , Jones K. , Kamath G.G. , Bowen‐Jones D. , Phillips R.P.
Published: August 2002

Aims

We studied the quality of opportunistic screening for diabetic retinopathy, which existed in the absence of a formal screening programme.

Methods

Patients referred during the period from June 1992 to May 1997 were identified. The findings and outcome at first ophthalmic consultation were used as surrogate measures to determine the appropriateness of referral. We considered patients to have had sight‐threatening retinopathy (STDR) if laser treatment or fluorescein angiography was recommended, or follow‐up at 6 months or less was arranged. Patients whose fundi could not be visualised were also included in the STDR group.

Results

Two hundred and eighty‐nine case records were available for analysis; 190 of these (65.7%) were considered to have STDR and 41 (14.2%) had other pathology, without concurrent diabetic retinopathy. The agreement between the referrer's diagnosis and the diagnosis made by the ophthalmologist was only fair, when comparing major diagnostic categories (kappa 0.35, 95% CI 0.30–0.41) and also for grading of retinopathy (kappa 0.30, 95% CI 0.23–0.37).

Conclusions

Our findings suggest that opportunistic screening can identify retinopathy only at a late stage. Our data should be valuable in measuring the benefits of formal screening for diabetic retinopathy as compared to previously existing services. Copyright © 2001 John Wiley & Sons, Ltd.
Time to reflect – what makes a difference in diabetes care?1
Authors: Avery Lorraine
Published: August 2002

Diabetes care is constantly evolving in response to new developments, innovative research, and the national agenda. The development of new technical advances, such as pen devices and glucose monitors, as well as the implementation of new working practices, has led to significant improvement in the management of diabetes. If, however, too much emphasis is placed on the advantages offered by these new advances, it is often easy to overlook or fail to recognise what makes a real difference to patients in the self‐management of diabetes. It is, therefore, essential to constantly reappraise and develop the provision of diabetes care, to ensure the best possible service for patients. The diabetes nurse specialist (DNS) plays a major part in shaping the future of diabetes care. How changes in care are translated into tangible benefits for patients depends largely on the dedication and commitment of the DNS, whose important role in the planning and implementation of diabetes care continues to increase and expand. The role of the DNS extends much further than simply providing medical care. DNSs are key contributors both to patient education and in ensuring that help and support is available to enable patients to feel more confident about managing their diabetes. Copyright © 2001 John Wiley & Sons, Ltd.
The ethical issues of the postmarketing surveillance of drug teratogenicity in Hungary
Authors: Czeizel Andrew E.
Published: August 2002

Purpose

To discuss some ethical issues of the postmarketing surveillance of drug teratogenicity.

Methods

To describe the three study groups of the Hungarian Case–Control Surveillance of Congenital Abnormalities with the three sources of data collection.

Results

This large population‐based surveillance system comprised 22 843 cases with congenital abnormalities, 38 151 population controls without congenital abnormalities and 834 patient controls with Down syndrome between 1980 and 1996. The major ethical issue is connected with personal data protection (confidential handling of data and informed consent). However, the Hungarian experiences displayed the ethical dilemma between the balance of individual and community rights and interest (mandatory notification, mandatory autopsy of infant deaths, personal identification number). Finally the medical consequences of publication bias at the evaluation of drug teratogenicity are presented as these also have some ethical aspects.

Conclusion

The ethical issues of postmarketing surveillance of drug teratogenicity show similarities with general epidemiological research but this public health system also has some special aspects. Copyright © 2001 John Wiley & Sons, Ltd.
Ethical issues arising in pharmacoepidemiologic research in a community hospital in Crete, Greece
Authors: Tzimis Leonidas
Published: August 2002

This paper presents the various issues encountered in planning, designing, performing, and reporting pharmacoepidemiologic research. Five hundred and fifty‐one indigent patients insured by Social Care visited the Hospital Pharmacy of Chania General Hospital, and were compared with 551 patients insured under Social Security funds who visited three community pharmacies. The study had no external funding. Before we started the study, we officially sought approval from the Scientific Committee of our Hospital and from the local Pharmaceutical Association. We asked also for approval from the Medical School of the University of Crete. Patient privacy was of great concern in the design and performance of the study. The law in Greece, according to the directives of the European Union, affects the way we use records in hospitals and protect patient rights. After these studies were completed, we made proposals to the authorities concerning continuous health education for both patients and health workers. Pharmacoepidemiologic research is difficult in hospitals outside universities or institutions, because of the lack of adequate funding and grants to support research staff. Copyright © 2001 John Wiley & Sons, Ltd.
Drug epidemiology in Italy: methods and ethical issues. The example of psychiatry
Authors: Barbui Corrado
Published: August 2002

Purpose

These notes aim at analysing current methods, ethical issues and major legislation changes related to drug epidemiology in Italy.

Methods

The design and conduct of two pharmacoepidemiological surveys carried out in the context of recent law dispositions on psychiatric care and confidentiality are presented.

Results

In 1978 law 180 stated that no more patients had to be admitted to psychiatric hospitals, and no more psychiatric hospitals had to be built. Chronic long‐stay patients were allowed to remain in hospitals. In 1994, however, financial law 724 established a deadline for the final closure of Italian psychiatric hospitals. A survey of more than 1000 patients living in eight state psychiatric hospitals was carried out to describe the social and clinical characteristics of the inpatient population and to monitor their community placement. In 1996 law 675 established that private and confidential information could not be used for any purpose without the patient's informed consent. However, this law was not implemented that year. A survey of benzodiazepine use among general practice patients was conducted without written informed consent.

Conclusions

The Italian legislation has been changing for some years, and regulations might still be modified in the near future. To increase ethical practices in pharmacoepidemiology scientists and clinical researchers should guarantee high standards in terms of research objectives, design and analyses. Potential conflict of interest should always be declared. Copyright © 2001 John Wiley & Sons, Ltd.
Precautions for proactive surveillance
Authors: Walker Alexander M. , Wise Robert P.
Published: August 2002

Four barriers confront the architects and users of surveillance systems. Bonferroni's Bind blunts our ability to act on real safety signals when the surveillance scheme is capable of producing realistic but wrong signals just by chance. The paradox of definitive data is that the results of a truly comprehensive scheme become untestable because there is no further relevant information to be had. Flexible priors augment the first two barriers by intensifying our instinctive cautions, and by giving almost any claim the appearance of empiric proof. The poverty of tabular summaries is that they presuppose the existance of relevant categories for tabulation, and that they fail to persuade. The resolution for proactive surveillance is sen/cen: high sensitivity to signals and vigorous censoring to filter out the noise. Copyright © 2001 John Wiley & Sons, Ltd.
A study of the photopolymerization kinetics of methyl methacrylate using novel benzophenone initiators
Authors: George Beena , Dhamodharan R
Published: August 2002

A series of novel bifunctional photoinitiators with benzophenone moieties were synthesized. Characterization of these molecules was performed using IR, UV, 1H NMR, 13C NMR and mass spectroscopy. Photopolymerization of methyl methacrylate, a model acrylate‐type monomer, was carried out with the bifunctional benzophenone molecules functioning as the photoinitiator and triethylamine as the co‐initiator. The progress of the polymerization was followed by dilatometry. The resulting plots of monomer conversion with time were used to evaluate the initial rates of polymerization. The relative enhancement/lowering of the rates of polymerization, with respect to benzophenone as the model photoinitiator, are interpreted in terms of the structure, and the photophysics of the initiator evaluated by nanosecond laser flash photolysis.

© 2001 Society of Chemical Industry
In situ FT‐IR and DSC investigation on the cure reaction of the dicyanate/diepoxide/diamine system
Authors: Lin Rong‐Hsien , Hsu Jiun‐Hsien
Published: August 2002

Cure reactions of a liquid aromatic dicyanate ester (1,1′‐bis(4‐cyanatophenyl)ethane, BEDCy) with a liquid bisphenol A epoxide (2,2‐bis(4‐glycidyloxyphenyl)propane, BADGE) and 4,4′‐diaminodiphenyl sulfone (DDS) were studied through correlation of the in situ FT‐IR spectroscopy and DSC in dynamic scanning mode. Before this system was examined, cure reactions of precursory systems of BADGE/DDS, BEDCy/BADGE and BEDCy/DDS were investigated separately. Cure reaction paths for each system are proposed. Some reactions in the precursory systems, such as polycyclotrimerization of dicyanate to form sym‐triazine and formation of alkyl isocyanurate, were not observed in the combined curing system BEDCy/BADGE/DDS. Four principal reaction paths are proposed for this curing system: (1) formation of oxazoline from the reaction between the epoxide and cyanate group; (2) reaction of epoxide with primary amine to form a hydroxyl group; (3) reaction of epoxide with the hydroxyl group to form an ether linkage; and (4) rearrangement of oxazoline to form oxazolidinone. Two distinct, but somewhat overlapping, exothermic peaks were observed on the DSC thermogram. The lower temperature peak on the DSC thermogram was primarily contributed by the first reaction path, whereas the higher temperature peak can mainly be attributed to the reaction paths 2, 3 and 4.

© 2001 Society of Chemical Industry
Reactivity ratios during radiation‐induced grafting of comonomer mixtures onto polyester fabrics
Authors: El‐Naggar A M , Zohdy M H , Sahar S M , Allam E A
Published: August 2002

Radiation‐induced grafting of binary mixtures of acrylonitrile (AN)/styrene (S) and acrylamide (AAm)/styrene (S) onto polyester fabric (PET) has been investigated. Synergism during radiation grafting was investigated by determining the graft yield fraction for each monomer in the final graft copolymer. Moreover, by knowing the mole fraction of each monomer in the grafting solution, the reactivity ratio of the individual monomers in the comonomer mixture during graft copolymerization could be determined: in the case of AN/S comonomer mixture, the calculated reactivity ratios for AN and S are 0.04 and 0.05, respectively; the calculated reactivity ratios of AAm and S in their comonomer mixture are 1.82 and 0.41, respectively.

© 2001 Society of Chemical Industry
The growing photovoltaic market in India
Authors: Chaurey Akanksha
Published: August 2002

Growth of the Indian photovoltaic industry, which produces 58 MWp at present, is influenced by global market trends, owing to the cost of the technology. It is also driven by local government initiatives and policies. The current structure of the market and its various segments is discussed, with the objective of studying the overall growth potential. A growth of 250 MWp in the next ten years is projected, with annual production reaching 35 MWp by 2010. In order to achieve the projected market volume, specific barriers related to technology and market development are identified, and enabling mechanisms are suggested. The Indian experience of barriers to adoption of PV technology, and their removal, are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Energy demand in solar home systems: the case of the communities in Ribeira Valley in the state of São Paulo, Brazil
Authors: Morante Federico , Zilles Roberto
Published: August 2002

An account is given of research on energy demand with solar home systems (SHSs) and the analysis of results of a field survey of 18 families located in 4 communities in the Ribeira Valley, on the southern coast of the State of São Paulo, Brazil. These families' energy consumption was measured over a one‐year period and, in order to do so, equipment that could determine the daily energy requirements in Ampere hour units was developed. The measurement instrument was coupled to existing (SHSs) in these communities and the data collection involved direct user participation. Data collection was done by hand and was intended to provide an interrelationship among the system, the user, and the researcher. The data provided social and cultural information related to the energy use in addition to essentially technical data. Through this methodology it was confirmed that energy demand is related to a number of factors which were not predicted before the survey. It was also confirmed that the people's behavior is reflected in the operation of the photovoltaic system as a whole. The results show that 55% of the SHSs researched showed consumption below 3 kW h/month. Copyright © 2001 John Wiley & Sons, Ltd.
Gas‐phase elimination reactions of 4‐arylideneimino‐1,2,4‐triazol‐3(2H)‐ones and their 3(2H)‐thione analogues
Authors: Al‐Awadi Nouria , Ibrahim Yehia , Kaul Kamini , Dib Hicham
Published: August 2002

4‐Arylideneimino‐1,2,4‐triazol‐3(2H)‐ones (1–4) and their thio analogues (5–8) were pyrolysed in the gas phase. The reactions were homogeneous and free from catalytic and radical pathways. Analysis of the pyrolysate showed the elimination products to be substituted benzonitriles and the corresponding 3‐hydroxy‐1,2,4‐triazoles and their thio analogues. The kinetic results and product analysis lend support to a reaction pathway involving a six‐membered transition state. At 500 K, the thiooxotriazoles 5–8 were found to be 103‐fold more reactive than the corresponding oxotriazoles 1–4. The reactivities of the 2‐oxotriazoles were compared with those of the substituted 2‐oxopyridine‐3‐carbonitriles. Copyright © 2001 John Wiley & Sons, Ltd.
A non‐topotactical thermal rearrangement without change of the macroscopic crystal shape
Authors: Kaupp G. , Schmeyers J. , Kato M. , Tanaka K. , Harada N. , Toda F.
Published: August 2002

The solid‐state thermal transformation of rac‐3,8‐di(tert‐butyl)‐1,5,6,10‐tetraphenyldeca‐3,4,6,7‐tetraene‐1,9‐diyne (1) into 4,5,9,10‐tetraphenyltricyclo[6.2.0.02,6]deca‐1,3,5,7,9‐pentaene (3) was investigated by x‐ray crystallography and atomic force microscopy (AFM) on two different faces. The enantiopure crystals of 1 that were picked from the conglomerate were monoclinic in the chiral space group C2 (No. 5) and were refined to an R‐factor of 0.0375. The monolayers stack in a straight manner without displacement leaving (001) cleavage planes. The layered structure is seen in AFM traces at certain stages of the reaction. The overall shape of single crystals of 1 does not change even though they turn deeply blue–green at 140–150 °C. However, the initial roughness in the micrometer region is flattened out or thoroughly rearranged by long‐range molecular movements giving phase rebuilding and phase transformation without detachment of the product from the parent crystal. Thus, the chemical reaction is limited to the surface region and to internal cracks of the crystal. A topotactical transformation is experimentally excluded and cannot be modelled at the given crystal structure. The chemical yield depends on the crystal size and is significant. The thermochrome 3 reverts to 1 but only in the outer surface region at anaerobic storage, whereas the known solid‐state oxidations occur in air. The topographic differences of these processes were traced with AFM. The release of strain in the surface region is evidenced by anisotropic crack formation that initially follows the crystal packing of 1 and could be imaged and compared with an ordinary microscope after the thermal reversion or oxidation. Copyright­© 2001 John Wiley & Sons, Ltd.
Experimental and theoretical determination of the dipole polarizability of dibenzothiophene
Authors: Soscún Humberto , Alvarado Ysaías , Hernández Javier , Hernández Paola , Atencio Reinaldo , Hinchliffe Alan
Published: August 2002

The dipole polarizability of dibenzothiophene is reported, which was measured experimentally by refractometry techniques, and evaluated theoretically with ab initio and density functional theory (DFT) methods in the 1A′ electronic ground state. The experimental polarizability was determined from measurements of the refraction index of dibenzothiophene in CCl4‐diluted solutions at five different frequencies to obtain the dispersion curve. The static polarizability of dibenzothiophene was determinated to be 2.358 × 10−23 esu from the extrapolation of the dispersion curve to zero frequency. Theoretical calculations were performed with fully C2V optimized geometries at both the HF/6‐31G** and HF/6‐31 + G(d,p) levels of theory, and we present comparisons with the crystal structure of dibenzothiophene and HF/6‐31G** geometry of benzothiophene previously reported. We calculated the dipole polarizability by using the coupled perturbed Hartree–Fock analytical method, with both the STO/6‐31 + G(d,p) and STO/6‐31 + G(3d,3p) basis sets. We investigated the effects of exchange and electron correlation on these properties by using the BLYP and B3LYP hybrid approaches. The B3LYP/6‐31 + G(3d,3p) average polarizability value of dibenzothiophene is 2.425 × 10−23 esu, which differs from the experimental static value by 3%. Copyright © 2001 John Wiley & Sons, Ltd.
Magnetic polyglycidylmethacrylate microspheres by dispersion polymerization
Authors: Horák Daniel
Published: August 2002

Composite polyglycidylmethacrylate [poly(GMA)] spherical microparticles capable of responding to magnetic fields were prepared by dispersion polymerization of GMA in the presence of iron oxides. The polymerization reaction was carried out in aqueous alcoholic media (methanol, ethanol, propan‐1‐ol, and butan‐1‐ol) using poly‐(N‐vinylpyrrolidone) and 2,2′‐azobisisobutyronitrile as a steric stabilizer and initiator, respectively. Quaternary ammonium salt (Aliquat 336) acting as an electrostatic costabilizer favorably affected dispersity. The solubility parameter of the reaction mixture determined the size of the resulting microspheres. In addition to the particle size distribution, the addition of iron oxide to the polymerization medium also caused a shift of the particle size to higher values. The results show that poly(GMA) particles contained up to 25 wt % iron oxide. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3707–3715, 2001
Atom transfer radical polymerization of n‐butyl acrylate from silica nanoparticles
Authors: Carrot G. , Diamanti S. , Manuszak M. , Charleux B. , Vairon J.‐P.
Published: August 2002

This article reports the synthesis of atom transfer radical polymerization (ATRP) of active initiators from well‐defined silica nanoparticles and the use of these ATRP initiators in the grafting of poly(n‐butyl acrylate) from the silica particle surface. ATRP does not require difficult synthetic conditions, and the process can be carried out in standard solvents in which the nanoparticles are suspended. This “grafting from” method ensures the covalent binding of all polymer chains to the nanoparticles because polymerization is initiated from moieties previously bound to the surface. Model reactions were first carried out to account for possible polymerization in diluted conditions as it was required to ensure the suspension stability. The use of n‐butyl acrylate as the monomer permits one to obtain nanocomposites with a hard core and a soft shell where film formation is facilitated. Characterization of the polymer‐grafted silica was done from NMR and Fourier transform infrared spectroscopies, dynamic light scattering, and DSC. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4294–4301, 2001
Synthesis of a soluble vinyl‐type polynorbornene with a half‐titanocene/methylaluminoxane catalyst
Authors: Wu Qing , Lu Yingying
Published: August 2002

Norbornene polymerization was performed with monocyclopentadienyltitanium tribenzyloxide activated with methylaluminoxane (MAO). The catalyst afforded a pure vinyl‐type polymer at temperatures below 80 °C and at appropriate MAO concentrations. However, at higher temperatures or high MAO concentrations, a portion of the titanium species was pyrolyzed to form an alkylidene compound that catalyzed the ring‐opening metathesis polymerization of norbornene. As a result, both vinyl‐type and ring‐opening polymers were produced under the reaction conditions. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1421–1425, 2002
Design of polyethers, thioethers, and amines with pendent iron moieties
Authors: Abd‐El‐Aziz A. S. , Todd E. K. , Ma G. Z.
Published: August 2002

Soluble organoiron polyethers, thioethers, and amines were synthesized via nucleophilic aromatic substitution reactions. The synthesis of these classes of organometallic polymers involved either the reaction of cyclopentadienyliron complexes of dichloroarenes with various oxygen and sulfur dinucleophiles or the reaction of ether‐ or amine‐containing diiron complexes with dithiols. Polymerization reactions with the diiron complexes gave rise to organoiron polymers with alternating ether/thioether or amine/thioether bridges. Removal of the iron moieties from the backbone of these polymers allowed for the production of the corresponding organic materials. Furthermore, the organometallic polymers had much higher solubilities than their organic analogues. Thermogravimetric analysis of the organoiron polymers indicated that the polymers lost their metallic moieties at approximately 200 °C, whereas degradation of the polymer backbones occurred around 500 °C. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1216–1231, 2001
Solvent effect on the free‐radical copolymerization of 2‐hydroxyethyl methacrylate with t‐butyl acrylate
Authors: Fernández‐Monreal Carmen , Martínez Gerardo , Sánchez‐Chaves Manuel , López Madruga Enrique
Published: August 2002

The free‐radical copolymerization of 2‐hydroxyethyl methacrylate with t‐butyl acrylate was carried out at 50 °C in bulk and in 3 mol · L−1 1,4‐dioxane and N,N′‐dimethylformamide solutions. Differences between the apparent reactivity ratios determined in this work indicated a noticeable solvent effect. This is explained with a qualitative bootstrap effect. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2043–2048, 2001
Rheological studies on the phase separation of hydroxypropylcellulose solution systems
Authors: Fujii Syuji , Sasaki Naoki , Nakata Mitsuo
Published: August 2002

Phase behavior of hydroxypropylcellulose (HPC) in a mixed solvent of glycerol and water was investigated by two different rheological methods: rheooptical birefringence measurement in an elongational flow field and viscometric measurement in a shear flow field. The association process of the HPC chain during phase separation observed by the elongational flow birefringence method was also investigated by the shear viscometric method. The temperature dependence of chain rigidity was determined by measuring the intrinsic viscosity, and change in the conformation was investigated by observing elongational flow birefringence over the temperature range from the one‐phase to inside a phase boundary. The results focus on the molecular process of phase separation. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1976–1986, 2001
Cavitation criterion for rubber materials: A review of void‐growth models
Authors: Fond C.
Published: August 2002

The principal criteria used to predict cavitation in rubber materials are reviewed, and experimental evidence is recalled for three different configurations: in the bulk, in the vicinity of a rigid particle, and in small rubber particles embedded in a rigid polymer matrix. Two major classes of cavitation criteria are defined, those based on an elastic instability (i.e., related to a stress state and finite strains) and those based on the energy balance (i.e., involving surface energies). The different criteria, in which various hyperelastic behavior laws are considered, are compared in numerical applications, and the tendencies are derived. The particular case of accounting for the surface tension of the rubber, a parameter common to the stress state and the energy balance, is treated in detail. It appears that the understanding of the genesis of a microcavity in a rubber material, when no pre‐existing flaw is assumed, still constitutes a difficulty for the analysis of mechanical damage in polymers containing a rubber phase. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2081–2096, 2001
Small‐angle X‐ray scattering and polymer melting: A model study
Authors: Crist Buckley
Published: August 2002

Small‐angle X‐ray scattering (SAXS) gives information on lamellar stacks in semicrystalline polymers. SAXS experiments have been used to follow the melting transition that occurs over a temperature range of 10 °C or more. One common feature is the increase in the average period by 50–100% during the melting process, a change that is often attributed to sequential melting of crystals in the lamellar stack. A quantitative treatment shows that the scattering experiment indicates only the original period, not the average period that increases throughout sequential melting. With this model, I discuss the relation between structural parameters of the melting structure and quantities derived from the SAXS intensity, the correlation function, and the interface distribution function. Uncertainties persist in our understanding of polymer melting. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2454–2460, 2001
Météorisation des Blocs de Granite à la Surface des Pédiments dans le Nord du Yukon, Canada
Authors: Bjornson Jean , Lauriol Bernard
Published: August 2002

This article describes how tors calve granite boulders which are then distributed in three zones on the surrounding pediments. The boulders are broken down to granules, sand, silt and clay on the surface of the pediments. The study site is located on a rounded hill of the Old Crow batholith near the Yukon‐Alaska border. The methods and techniques used were grain size analysis, rock and sediment geochemistry and boulder fabric. Results show that boulders become smaller and less frequent on the pediment as distance from the tor increases. Weathering processes disaggregate the boulders before they reach the talwegs. Chronological evaluation suggests that 10s to 100s ka are necessary for weathering to reduce the boulders to fine particles. Copyright © 2001 John Wiley & Sons, Ltd.