bluuebunny/crossref_metadata_2025 huggingface dataset:
Local defect correction with different grid types
Authors: Nefedov V. , Mattheij R. M. M.
Published: October 2002

For a Poisson problem with a solution having large gradients in (nearly) circular subregions a local defect correction method is considered. The problem on the global domain is discretized on a cartesian grid, whereas the restriction of the problem to a circular subdomain is discretized on a polar grid. The two discretizations are then combined in an iterative way. We show that LDC can be viewed as an iterative method for the Poisson equation on a single composite cartesian‐polar grid. The efficiency of methods is illustrated by numerical examples. © 2002 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 18: 454–468, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/num.10018
The involvement of matrix glycoproteins in vascular calcification and fibrosis: an immunohistochemical study
Authors: Canfield A. E. , Farrington C. , Dziobon M. D. , Boot‐Handford R. P. , Heagerty A. M. , Kumar S. N. , Roberts I. S. D.
Published: October 2002

Calcification and fibrointimal proliferation are associated with advanced complicated atherosclerosis in large arteries but may also occur in smaller vessels, resulting in ischaemic tissue necrosis. This study investigates whether the mechanisms of calcification and intimal fibrosis are similar in vessels of different sizes. The localization of osteopontin (OPN), matrix Gla protein (MGP), thrombospondin‐1 (TSP‐1), and cartilage oligomeric matrix protein (COMP) was investigated in three types of human vascular lesions: atherosclerosis, chronic vascular rejection (CVR) in renal allografts, and calcific uraemic arteriolopathy (calciphylaxis). These lesions were chosen as they affect different sized blood vessels and they exhibit a fibroproliferative intimal reaction, with or without calcification, resulting in luminal obliteration and ischaemic complications. OPN, MGP, TSP‐1, and COMP were not detected in normal blood vessels. However, OPN and MGP were expressed at sites of calcification within atherosclerotic lesions and in microvessels in calciphylaxis, suggesting that calcification in different sized vessels may occur by a common mechanism. These proteins were not detected in areas of fibrointimal proliferation. In contrast, TSP‐1 was localized primarily within the fibrous tissue of atherosclerotic lesions and was also expressed in the expanded fibrous intima of arteries showing CVR. COMP was localized primarily within the fibrous tissue under the lipid core of the majority of advanced atherosclerotic lesions. TSP‐1 and COMP were also detected in areas of microcalcification in atherosclerotic lesions and TSP‐1 was detected adjacent to areas of calcification in calciphylaxis. However, neither TSP‐1 nor COMP was localized to calcific foci within these lesions. The localization of OPN, MGP, TSP‐1, and COMP to pathological, but not normal arterial intima supports a pathogenetic role for these proteins in the development of vascular fibrosis and calcification. Modulation of their production and activity may offer a novel approach to the therapy of a number of vascular diseases. Copyright © 2001 John Wiley & Sons, Ltd.
Evidence for activation of the renin–angiotensin system in the human prostate: increased angiotensin II and reduced AT1 receptor expression in benign prostatic hyperplasia
Authors: Dinh Diem T. , Frauman Albert G. , Somers Gino R. , Ohishi Mitsuru , Zhou Jialong , Casley David J. , Johnston Colin I. , Fabiani Maurice E.
Published: October 2002

The expression and cellular localization of angiotensin II (Ang II) and AT1 receptor proteins were examined in the normal human prostate and benign prostatic hyperplasia (BPH) by immunohistochemistry. In the normal prostate, Ang II immunoreactivity was localized to the basal layer of the epithelium and AT1 receptor immunostaining was found predominantly on stromal smooth muscle and also on vascular smooth muscle of prostatic blood vessels. Ang II immunoreactivity was markedly increased in hyperplastic acini in BPH compared with acini in the normal prostate (normal: 7.4±0.2%, n=5 vs. BPH: 22.7±1.9%, n=5, p<0.001). However, AT1 receptor immunoreactivity was significantly decreased in BPH compared with the normal prostate [normal: 16.4±2.2%, n=4 vs. BPH: 9.4±1.3%, n=5, p<0.05 (p=0.025)]. The present study demonstrates the presence of Ang II peptide in the basal layer of the epithelium and AT1 receptors on stromal smooth muscle, suggesting that Ang II may mediate paracrine functions on cellular growth and smooth muscle tone in the human prostate. Furthermore, AT1 receptor down‐regulation in BPH may be due to receptor hyperstimulation by increased local levels of Ang II in BPH. These data extend previous findings in support of the novel concept that overactivity of the renin–angiotensin system (RAS) may be involved in the pathophysiology of BPH. Copyright © 2001 John Wiley & Sons, Ltd.
Expression of S100A4 protein is associated with metastasis and reduced survival in human bladder cancer
Authors: Davies Barry R. , O'Donnell Marie , Durkan Garrett C. , Rudland Philip S. , Barraclough Roger , Neal David E. , Kilian Mellon J.
Published: October 2002

The calcium‐binding protein S100A4 induces the metastatic phenotype in rodent models of breast cancer and its expression correlates strongly with reduced survival in human breast cancer. The expression of S100A4 in normal bladders and 101 bladder tumours has been studied using immunocytochemistry. Moderate or strong expression of S100A4 was found in 28% of the tumours, whilst the remaining tumours and normal urothelium either failed to stain or showed weak staining. S100A4 staining was more frequently observed in invasive bladder tumours than in non‐invasive tumours (p<0.05). In invasive tumours, S100A4 staining was usually strongest in invasive regions and single infiltrating cells. Statistically significant associations were found between S100A4 expression and metastasis (p=0.0003) and reduced survival (p<0.0001). It is concluded that S100A4 expression may play an important role in bladder cancer and may identify a subgroup of patients at increased risk of metastasis who should be considered for adjuvant systemic therapy. Copyright © 2002 John Wiley & Sons, Ltd.
HLA‐G and its KIR ligands in cancer – another enigma yet to be solved?
Authors: Urosevic Mirjana , Trojan Andreas , Dummer Reinhard
Published: October 2002

Alterations of antigen‐presenting human leukocyte antigen (HLA) molecules often occur in cancer and represent one of the mechanisms by which tumours evade host immunosurveillance. One such molecule, HLA‐G, was recently implicated in the same context. HLA‐G is thought to mediate the tolerance of the semi‐allogeneic fetus during pregnancy, by inhibiting maternal immune response through interaction with different HLA‐G‐recognizing killer‐cell inhibitory receptors (KIRs). A report in this issue of the journal demonstrates for the first time the expression of HLA‐G and its KIR ligand, ILT‐2 in human breast cancer. Apart from the up‐regulation on tumour cells, the authors describe HLA‐G induction on the macrophages and T cells infiltrating the breast cancer lesions. Moreover, a subset of infiltrating cells also expressed HLA‐G‐recognizing KIR, ILT‐2. This editorial discusses the induction of HLA‐G and related KIR molecules as another mechanism for tumours to escape immune recognition. Copyright © 2002 John Wiley & Sons, Ltd.
Loss of heterozygosity at 18q21 region in gastric cancer involves a number of cancer‐related genes and correlates with stage and histology, but lacks independent prognostic value
Authors: Candusso M. E. , Luinetti O. , Villani L. , Alberizzi P. , Klersy C. , Fiocca R. , Ranzani G. N. , Solcia E.
Published: October 2002

Several studies support a role of 18q21 LOH, involving the DCC locus, in colorectal cancer progression; however, its contribution to the natural history of gastric cancer is less clear. Recently, a number of cancer‐related genes have been mapped in the 18q21 region, either centromeric or telomeric to DCC. This study searched for 18q21 LOH in 161 gastric cancers representative of all tumour stages and main histological types. To this purpose, seven highly polymorphic markers were used flanking the 18q21 band and spanning the entire region. Thirty‐four out of 147 (23.1%) informative cases showed LOH. In 27 of 34 cases (79%), LOH involved all the informative loci. The remaining seven cases showed LOH at more telomeric sites and retained heterozygosity at more centromeric markers, mostly those proximal to the DCC gene. A strong correlation between 18q21 LOH and level of gastric wall invasion, lymph node metastases, or stage was found in cohesive (glandular+solid) and mixed tumours, but not in diffuse cancers. Cox univariate and multivariate analysis showed that invasion level, lymph node metastases, distant metastases, TNM stage, and histology were effective predictors of survival, whereas 18q21 LOH did not show predictive power. The simultaneous deletion of a variety of cancer‐related genes with different and even opposite roles might explain why, apparently, 18q21 LOH does not per se contribute significantly to the natural history of gastric cancer, despite strong correlation with stage. Copyright © 2002 John Wiley & Sons, Ltd.
Clonal T cell receptor γ‐chain gene rearrangement by PCR‐based GeneScan analysis in the skin and blood of patients with parapsoriasis and early‐stage mycosis fungoides
Authors: Klemke Claus‐Detlev , Dippel Edgar , Dembinski Antje , Pönitz Nina , Assaf Chalid , Hummel Michael , Stein Harald , Goerdt Sergij
Published: October 2002

Cutaneous T cell lymphoma (CTCL) and reactive T cell skin diseases represent opposite ends of a spectrum of diseases ranging from overtly malignant to persistently benign. Within this spectrum, the parapsoriasis group is not clearly defined regarding malignant potential. In contrast to consistent findings in advanced‐stage CTCL, clonality analysis of parapsoriasis has produced conflicting results in previous studies. As T cell receptor γ‐chain polymerase chain reaction GeneScan analysis (TCR‐γ‐PCR‐GSA) stands out by its sensitivity, its accuracy in size determination of PCR products, its capacity to identify false positives by repeated analysis and its easy applicability, this approach was used to analyse the clonality status of 41 patients with borderline T cell lymphoproliferative skin diseases, including parapsoriasis (n=27) and early‐stage mycosis fungoides (MF) (n=14). A monoclonal T cell infiltrate was demonstrated by repeated TCR‐γ‐PCR‐GSA in lesional skin specimens in 19.2% of parapsoriasis patients and in 66.6% of early‐stage MF cases (p=0.013). In peripheral blood, a monoclonal T cell population was found in a similar percentage of parapsoriasis and of early‐stage MF patients (26.7% versus 12.5%; p=0.611). A detailed analysis of parapsoriasis subentities, namely small and large plaque parapsoriasis, and parapsoriasis lichenoides, revealed monoclonality in 2(6)/2(5), 3(14)/2(8) and 0(6)/0/(3) of the skin and peripheral blood specimens, respectively. The high detection rate of false positive cases by repeated analysis (20–37.5%) provides a corrected perspective for the high rates of dominant T cell clones found by others in the peripheral blood of such patients. From the results obtained, three major conclusions can be drawn: firstly, CTCL is clearly associated with detection of monoclonality, even in its early stages; secondly, monoclonality is not a prerequisite for potential CTCL precursor entities; and thirdly, recirculating malignant T cells identical to the skin clone are not readily detected in parapsoriasis or early‐stage MF, but may rather indicate disease progression. Copyright © 2002 John Wiley & Sons, Ltd.
Genetic and epigenetic alterations of the INK4a–ARF pathway in cholangiocarcinoma
Authors: Tannapfel Andrea , Sommerer Florian , Benicke Markus , Weinans Lars , Katalinic Alexander , Geißler Felix , Uhlmann Dirk , Hauss Johann , Wittekind Christian
Published: October 2002

The INK4a–ARF locus, located on chromosome 9p21, encodes two cell‐cycle regulatory proteins, p16INK4a and p14ARF, acting through the Rb–CDK4 and p53 pathways. To study the contribution of each pathway in the tumourigenesis of cholangiocarcinoma, the alterations of p14ARF, p16INK4a, p53, and pRb were analysed. After microdissection, DNAs from 51 cholangiocarcinomas were analysed by methylation‐specific PCR (MSP), restriction‐enzyme related polymerase chain reaction (RE‐PCR), microsatellite analysis, mRNA expression, and DNA sequencing. Immunohistochemistry of p14ARF, p16INK4a, p53, and pRb was also performed. Promoter methylation of p14ARF was found in 13/51 cases (25%) and p16INK4a showed aberrant promoter methylation in 39/51 cases (76%) which correlated with loss of mRNA transcription. Two tumours (4%) had homozygous deletion of the INK4a–ARF locus. Specific mutations of both exons were not detected. p14ARF inactivation appeared in the context of an unmethylated p16INK4a promoter in eight of 13 cases (61%) of the carcinomas methylated at p14ARF. Mutations of p53 were found in 19 of 51 tumours (37%), and four of them (21%) harboured p14ARF inactivation. The pRb protein was detected in 30/51 (59%) tumours examined. The absence of pRB protein did not correlate with any of the examined parameters. Alterations of the INK4a–ARF locus, pRB or p53 status could not be established as independent prognostic factors in these tumours. These findings indicate that the INK4a–ARF locus is frequently inactivated in cholangiocarcinoma of the liver and occurs independently of the status of p53 or pRb. Copyright © 2002 John Wiley & Sons, Ltd.
p63 immunoreactivity in lung cancer: yet another player in the development of squamous cell carcinomas?
Authors: Pelosi Giuseppe , Pasini Felice , Olsen Stenholm Catharina , Pastorino Ugo , Maisonneuve Patrick , Sonzogni Angelica , Maffini Fausto , Pruneri Giancarlo , Fraggetta Filippo , Cavallon Alessandra , Roz Elena , Iannucci Antonio , Bresaola Enrica , Viale Giuseppe
Published: October 2002

The p63 protein, a member of the p53 family of nuclear transcription factors, is characterized by different capabilities of transactivating reporter genes, inducing apoptosis, and functioning as dominant‐negative agent. This study evaluated the prevalence and prognostic implications of p63 immunoreactivity in 221 patients with stage I non‐small cell lung carcinoma (NSCLC) and in 57 patients with stage I–IV neuroendocrine tumours (NET). The results were correlated with the tumour proliferative fraction, the accumulation of p53 protein, and with patient survival. p63 immunoreactivity was seen in 109/118 squamous cell carcinomas, 15/95 adenocarcinomas, 2/2 adenosquamous carcinomas, 4/6 large cell carcinomas, 9/20 poorly differentiated NET, and 1/37 typical and atypical carcinoids (p < 0.001). Furthermore, the prevalence of p63‐immunoreactive cells increased progressively from pre‐neoplastic and pre‐invasive lesions to invasive squamous cell carcinomas. In these latter tumours, but not in adenocarcinomas, p63 immunoreactivity correlated directly with the tumour proliferative fraction (p = 0.028), and inversely with the tumour grade (p = 0.004). No relationship was found with p53 protein immunoreactivity or the other clinico‐pathological variables examined. Although p63 is likely to be involved in the development of pulmonary squamous cell carcinoma, it does not carry any prognostic implication for NSCLC patients. Copyright © 2002 John Wiley & Sons, Ltd.
Adult stem cell plasticity
Authors: Poulsom Richard , Alison Malcolm R. , Forbes Stuart J. , Wright Nicholas A.
Published: October 2002

Observations made in the last few years support the existence of pathways, in adult humans and rodents, that allow adult stem cells to be surprisingly flexible in their differentiation repertoires. Termed plasticity, this property allows adult stem cells, assumed, until now, to be committed to generating a fixed range of progeny, to switch, when they have been relocated, to make other specialized sets of cells appropriate to their new niche. Reprogramming of some adult stem cells can occur in vivo; the stem cells normally resident in bone marrow appear particularly flexible and are able to contribute usefully to multiple recipient organs. This process produces cells with specialized structural and metabolic adaptations commensurate with their new locations. In a few examples, the degree of support is sufficient to assist or even rescue recipient mice from genetic defects. Some studies provide evidence for the expansion of the reprogrammed cells locally, but in most it remains possible that cells arrive and redifferentiate, but are no longer stem cells. Nevertheless, the fact that appropriately differentiated cells are delivered deep within organs simply by injection of bone marrow cells should make us think differently about the way that organs regenerate and repair. Migratory pathways for stem cells in adult organisms may exist that could be exploited to effect repairs using an individual's own stem cells, perhaps after gene therapy. Logical extensions of this concept are that a transplanted organ would become affected by the genetic susceptibilities of the recipient, alleles that re‐express themselves via marrow‐derived stem cells, and that plasticity after bone marrow transplantation would also transfer different phenotypes, affecting important parameters such as susceptibility to long‐term complications of diabetes, or the ability to metabolize drugs in the liver. This article reviews some of the evidence for stem cell plasticity in rodents and man. Copyright © 2002 John Wiley & Sons, Ltd.
Detection of N‐myc amplification by FISH in immature areas of fixed neuroblastomas: more efficient than Southern blot/PCR
Authors: Sartelet Hervé , Grossi Laurence , Pasquier Dominique , Combaret Valérie , Bouvier Raymonde , Ranchère Dominique , Plantaz Dominique , Munzer Martine , Philip Thierry , Birembaut Philippe , Zahm Jean‐Marie , Bergeron Christophe , Gaillard Dominique , Pasquier Basile
Published: October 2002

N‐myc amplification is a major prognostic factor in neuroblastomas and is systematically investigated by Southern blot or polymerase chain reaction (PCR). A retrospective study of N ‐myc amplification has been carried out using fluorescence in situ hybridization (FISH) in 97 fixed neuroblastomas. For each tumour, FISH was performed on the area that contained the most immature neuroblasts. Among these 97 neuroblastomas, 16 were amplified and 12 were not interpretable. FISH was not interpretable in six cases. All neuroblastomas with N‐myc amplification detected by Southern blot/PCR were amplified with FISH, except three that were not interpretable. Four tumours that were not interpretable in Southern blot/PCR contained more than five copies of N‐myc by FISH: one was aneuploid and three were truly amplified, containing more than ten copies of N‐myc. Among these three patients, two died in a short time of their tumours. Ten cases were not amplified by Southern blot/PCR and showed more than five copies by FISH: four were aneuploid and two showed heterogeneous amplification, with a few cells clearly amplified whereas most were not. Four cases were amplified, of which two patients died of their tumours. This study confirms that when applied to the most immature areas of fixed neuroblastomas, FISH displayed a higher sensitivity than molecular techniques (p < 0.001) and could detect heterogeneous amplification. FISH could therefore become an important complementary procedure in assessing prognosis in neuroblastomas. Copyright © 2002 John Wiley & Sons, Ltd.
Invasive testing for the karyotyping of mid‐trimester intrauterine fetal death (IUFD): a pilot study
Authors: Howarth E. S. , Konje J. C. , Healey K. A. , Duckett D. P. , Scudamore I. W. , Taylor D. J.
Published: October 2002

Introduction

Aneuploidy remains a common cause of fetal loss after the first trimester. Conventional karyotyping from fetal solid tissues post‐delivery unfortunately has a poor success rate particularly where the fetus is macerated. To overcome this we obtained amniocentesis and/or chorionic villus samples from mid‐trimester intrauterine fetal deaths (IUFDs) prior to medical termination of pregnancy.

Subjects

Ten women with diagnosed IUFD between 12 and 24 weeks' gestation underwent amniocentesis and/or CVS performed after counselling.

Results

Successful karyotypes were obtained in all pregnancies. Five of the ten pregnancies were complicated by aneuploidy (two with trisomy 21, two with trisomy 18, and one with trisomy 13).

Conclusion

The high rate of aneuploidy (50%) in this small cohort emphasises the need for karyotyping. A successful karyotype in all ten pregnancies demonstrates the value of offering these procedures before a termination of pregnancy. We would recommend the adoption of this approach in the management of IUFD occurring after the first trimester. Copyright © 2002 John Wiley & Sons, Ltd.
Pilot study for the neonatal screening of fragile X syndrome
Authors: Rifé M. , Mallolas J. , Badenas C. , Tazón B. , Miguélez M. Rodríguez , Pàmpols T. , Sànchez A. , Milà M.
Published: October 2002

An Erratum has been published for this article in Prenatal Diagnosis 23 (9), 2003, 771.

Fragile X syndrome (SFX) is the commonest form of inherited mental retardation. Due to the highly variable phenotype clinical diagnosis is complicated. In nearly all cases, the disorder is caused by expansion of a CGG‐repeat in the 5′‐untranslated region of the FMR1 (fragile X mental retardation‐1) gene. We have evaluated the feasibility, efficiency and costs of two methodologies in order to develop a simple test to screen large populations: PCR and fragile X mental retardation‐1 protein (FMRP) immunodetection. We studied 100 newborn males using PCR and immunodetection (26.91 Euro). All but one amplified the CGG repeat of the FMR1 gene within the normal size range. The sample that failed to amplify showed only 28% of FMRP expression by immunodetection study; both results indicated an affected male. A further 100 males were studied only by polymerase chain reaction (PCR) (7.8 Euro); all of them amplified within the normal size range. Both methodologies, PCR and immunodetection, are feasible for screening large populations, PCR being the most suitable, economical and less time‐consuming. However, it is advisable to keep slides for immunodetection when PCR fails or the external control shows no amplification. Early detection of SFX‐affected individuals would represent a great benefit for their maximum social integration, due to appropriate treatment and early stimulation and would permit a cascade screening in their pedigree. Copyright © 2002 John Wiley & Sons, Ltd.
A non‐invasive frequent home blood glucose monitor
Authors: Lenzen H , Barrow BA , White S , Holman RR
Published: October 2002

Attaining near‐normoglycaemia in patients with diabetes is essential if diabetes‐related complications are to be minimised. Attempts to optimise glycaemic control are often limited by the infrequent nature of current home blood glucose monitoring systems and fear of hypoglycaemia. We evaluated the potential benefit of the GlucoWatch® Biographer, a non‐invasive glucose monitoring device designed to give a frequent measure of blood glucose and provide early warning of hypoglycaemia or hyperglycaemia, in five subjects with type 1 diabetes over a three week period.

Subjects found the device easy to use, obtaining 762 usable readings out of a possible 1168 (65%) although all experienced some degree of skin irritation. They felt that the device facilitated continuous blood glucose monitoring and thought that high and low glucose alarms were helpful. Subjects experienced between one and six hypoglycaemia alarms per day, usually 20 to 60 min before the appearance of clinical symptoms, and between zero and four hyperglycaemia alarms per day. The degree to which the device can improve glycaemic control remains to be evaluated. Copyright © 2002 John Wiley & Sons, Ltd.
Self‐study material to prevent severe hypoglycaemia in children and adolescents with type 1 diabetes. A prospective intervention study
Authors: Nordfeldt S , Ludvigsson J
Published: October 2002

The aim of this study was to evaluate use of self‐study material in diabetes education aimed at prevention of severe hypoglycaemia. Targeted self‐study brochures (and video programs) regarding diabetes self‐care and prevention of severe hypoglycaemia were mailed to all patients in early 1997 (and in 1999): a geographic population of 122–139 intensively treated type 1 diabetes patients yearly, aged 1–18 years (mean 12.2, SD 4.3), between 1994 and 1999. Yearly mean HbA1c (1.15% below DCCT level) ranged from 4.1 to 11.6% (mean 6.6, SD 1.1), age at onset 0.5–17.4 years (mean 7.6, SD 4.0) and duration 0.1–16.6 years (mean 4.6, SD 3.7). Main outcomes were patient attitudes to the interventions, perceived benefit, level of use, severe hypoglycaemia, and HbA1c.

Eighty‐six percent of responders stated that the video was valuable. Perceived benefit was higher for the hypoglycaemia prevention video than for the brochure (p = 0.016). Those with severe hypoglycaemia the preceding year indicated greater benefit from the hypoglycaemia prevention brochure than others (p = 0.039). Average yearly incidence of severe hypoglycaemia with unconsciousness decreased from 13% in 1994–1996 to 9% (ns) in 1997–1999. The per patient cost of the material was <Euro 10.

Conclusion. Self‐study material can reach high dissemination at a low cost. It also seems to have contributed to a decrease in severe hypoglycaemia, but controlled studies are needed. There is a great need for good quality patient/consumer information materials dealing with aspects of general management and risk prevention in diabetes treatment.

The findings may have implications for other topics, ages, and diagnosis groups. Copyright © 2002 John Wiley & Sons, Ltd.
Development and validation of the preschool learning behaviors scale
Authors: McDermott Paul A. , Leigh Nanette M. , Perry Marlo A.
Published: October 2002

This article presents the design, national standardization, and validation of the Preschool Learning Behaviors Scale (McDermott, Green, Francis, & Stott, 2000). A normative sample (N = 100) of 3‐ to 5–1/2‐year‐olds was configured to the U.S. Census, wherewith factor analyses yielded distinct and reliable dimensions of Competence Motivation, Attention/Persistence, and Attitude Toward Learning. The solution was invariant in an independent national sample (N = 170) and generalizable across child sex, age, ethnicity, and parent education level. Three‐week stability and interobserver agreement were supported with a local Head Start sample (N = 52). Bivariate and canonical correlations demonstrated validity convergence with indices of social skills, divergence from behavior problems, and substantial independence from cognitive ability. Implications and future research are considered. © 2002 Wiley Periodicals, Inc.
Enhancing science performance in students with learning disabilities using cover, copy, and compare: A student shows the way
Authors: Smith Tawnya J. , Dittmer Karen I. , Skinner Christopher H.
Published: October 2002

A student who participated in a previous study where he was trained to use a self‐managed academic intervention known as cover, copy, and compare (CCC) to enhance his mathematics performance developed the specific intervention used in the current study. Without prompting, this student adapted and employed this procedure to learn bone in the human body. In the current study a multiple baseline across tasks design was used to determine if CCC could be used to enhance accuracy in identifying parts of the human heart in three students with learning disabilities. Three students learned how to perform the self‐management procedures during one session that lasted less than 15 minutes. Results showed that immediately after implementing the CCC intervention students' accuracy improved. Following 11 brief sessions, students were able to identify 15 parts of a human heart with an overall accuracy of 80% over 2 consecutive days. Discussion focuses on limitations and implications of this study and school psychologists' and students' contributions to the development and empirical validation of academic interventions. © 2002 Wiley Periodicals, Inc.
Interrater agreement for discriminant classifications for the adjustment scales for children and adolescents
Authors: Canivez Gary L. , Watkins Marley W. , Schaefer Barbara A.
Published: October 2002

Investigation of interrater agreement for the Adjustment Scales for Children and Adolescents (ASCA) discriminant classifications is reported. Two teaching professionals or paraprofessionals working in the same classroom for a minimum of 1 hour per day provided independent ratings of the same child using the ASCA. A total of 119 students ranging in age from 7 to 18 years were independently rated on the ASCA. Results indicated significant and moderate to substantial interrater agreement for the discriminant classifications. © 2002 Wiley Periodicals, Inc.
Creating school environments that deter antisocial behaviors in youth
Authors: Reinke Wendy M. , Herman Keith C.
Published: October 2002

School violence has become of paramount concern in recent years, leaving many schools unprepared to deal with the varied problems students bring to the classroom. Conditions within the school can be readily identified that predict and contribute to problematic behavior. The success of preventive and intervention programs for youth violence hinges upon recognizing and modifying aspects of school climate, teacher/school personnel interactions with students, and school structure. Several of these aspects are identified in this article and suggestions for improving the educational environment to prevent the development of antisocial behaviors in youth are offered. © 2002 Wiley Periodicals, Inc.
Teacher attributions of student failure and teacher behavior toward the failing student
Authors: Georgiou Stelios N. , Christou Constantinos , Stavrinides Panayiotis , Panaoura Georgia
Published: October 2002

The aim of this study was to examine the relation between teacher attributions of student school failure and teacher behavior toward the failing student. A structural equation model was proposed and its ability to fit the data was tested. It was found that teachers tend to behave in ways that indicate more pity and less anger when they attribute a student's low achievement to her or his low abilities, whereas they express more anger when attributing low achievement to the student's low effort. In contrast to previous research that argues in favor of anger as a high ability cue, this study has found that the presence of anger was associated with a teacher tendency to give‐up efforts to help the student improve. This giving‐up behavior was negatively related to the tendency of the teachers to accept some responsibility for the student failure. © 2002 Wiley Periodicals, Inc.
Ab initio analysis on metal ion catalysis in the enolization reactions of some acetylheterocycles: kinetics of the enolization reactions of 3‐acetyl‐5‐methylisoxazole, 5‐acetyl‐3‐methylisoxazole and 3(5)‐acetylpyrazole
Authors: Fontana Antonella , Maria Paolo De , Pierini Marco , Siani Gabriella , Cerritelli Simona , Macaluso Gabriella
Published: October 2002

Kinetic data on the enolization reaction of 3‐acetyl‐5‐methylisoxazole, 5‐acetyl‐3‐methylisoxazole, 3(5)‐acetylpyrazole and some previously studied acetylheterocycles have been the object of a comprehensive ab initio analysis. Enolization rate constants were measured spectrophotometrically by the halogen trapping technique at 25 °C and ionic strength of 0.3 mol dm−3 in water, in acetate buffers, in dilute hydrochloric acid, in dilute sodium hydroxide and in the presence of some metal ion salts. In the spontaneous (water) and base (acetate) catalysed reactions the ketones investigated are generally more reactive than acetophenone, according to the electron‐withdrawing effect of the heterocyclic ring compared with the benzene ring. In particular, acetylisoxazoles, 3(5)‐acetylpyrazole and acetylthiazoles are more reactive than acetylfurans, 2‐acetylpyrrole and acetylthiophenes respectively, and this can be attributed to the additional effect of the second heteroatom in the heterocyclic moiety. On the other hand, the compounds investigated are generally less reactive than acetophenone in the H3O+‐catalysed reaction. Ab initio calculations on the relative stability of the protonated and unprotonated forms of the substrates investigated have been compared with the kinetic results obtained in acid solutions. As far as the metal ion catalysis is concerned, an approach in terms of ΔΔE can give an estimate of the combined contributions of charge densities and frontier orbitals to the interaction of the substrate with the metal ion catalyst. A comparison of experimental metal activating factor values and ab initio calculations outlines the importance of charge density on the carbonyl oxygen atom of acetylheterocycles with one heteroatom. An analogous comparison for acetylheterocycles with two heteroatoms suggests the formation of a chelate complex or transition state, in which the metal ion coordinates both the carbonyl oxygen and the aza nitrogen, whenever these two atoms are suitably placed within the molecular structure of the acetylheterocycle. Copyright © 2002 John Wiley & Sons, Ltd.
Conformational dependence of substituent effects in the solvolyses of the 1,1‐diphenyl‐2,2,2‐trifluoroethyl system
Authors: Fujio Mizue , Kim Hyun‐Joong , Uddin Md. Khabir , Yoh Soo‐Dong , Rappoport Zvi , Tsuno Yuho
Published: October 2002

The substituent effects on the solvolysis of 1‐X‐phenyl‐1‐Y‐phenyl‐2,2,2‐trifluoroethyl tosylates were analyzed on the basis of the Yukawa–Tsuno equation. For the solvolysis of the symmetrically disubstituted X = Y subseries, an excellent linear correlation was obtained. However, in the solvolyses of series of varying X with a fixed‐Y subset, the substituent effects were found to give significantly concave Y–T correlations. The ρ value for the Y–T correlations changes significantly with the fixed Y substituent. There is a qualitative trend of a linear decrease in the ρ value as the fixed‐Y substituent of the respective subset becomes more electron donating. The non‐linearity of substituent effects was attributed to a substituent‐induced conformational change of the transition state, which could be simulated by calculation of the preferred conformation of the intermediate carbocation. A molecular orbital optimization method was applied to determine the preferred conformations of the α,α‐diarylcarbenium ions derived from the title systems. The symmetrical carbenium ions X = Y have a preferred propeller shape conformation with twist angles differing by 14° (E conformation), whereas in the unsymmetrical systems X ≠ Y the two aryl rings are much more (>30°) differently twisted in the preferred conformation (PT conformation). The linear correlation found for the symmetrical subseries is essentially an outcome of the E conformation of the transition state. In unsymmetrical cases, the substituent effect correlation in any Y subset should reflect the conformational arrangements, E
X, P
X and T
X of the variable X‐aryl group, depending on relative σ values of X and Y. The substituent effects in the Y‐subsets were successfully treated by three different Y‐independent correlations for the preferred conformational arrangements: E correlation for substituents when (σ
X − σ
Y) ≅ 0, P
X correlation when (σ
X − σ
Y) ≪0 and T
X correlation for the (σ
X − σ
Y) ≫0 class, respectively. Copyright © 2002 John Wiley & Sons, Ltd.
Formation and isomerization of C120: considerations of symmetry, kinetics and thermodynamics
Authors: Halevi Emil Amitai
Published: October 2002

An orbital‐symmetry analysis (OCAMS) of the dimerization of C60 to its stable (D2h) dimer 1 indicates that the reaction cannot proceed along a totally symmetric pathway but that the reaction‐path symmetry must be reduced at least to C2h. Similarly, one‐step conversion of 1 to its isomer 3 (also D2h), which has been proposed as an intermediate for the intercalation of helium atoms into C60, is also limited to a C2h pathway. As neither of these pathways is geometrically appropriate, it is predicted that both reactions proceed stepwise. Semi‐empirical computations (AM1/UHF) confirmed this prediction: in the dimerization, a transoid singlet biradical (2) is formed, and then closes readily to 1 after rotation about its newly formed bond. An intermediate (4) of C2v symmetry is detected along the pathway for isomerization of 1 to 3. THERMO computations (AM1/RHF) indicated that both dimers should be in thermal equilibrium with C60 at moderate temperatures, but that their equilibrium concentrations in the gas phase would be exceedingly small under thermally accessible conditions. The limitations of the computational method employed and their bearing on the reliability of the results are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Study of inclusion complexes of acridine with β‐ and (2,6‐di‐O‐methyl)‐β‐cyclodextrin by use of solubility diagrams and NMR spectroscopy
Authors: Correia Isabelle , Bezzenine Nabil , Ronzani Nello , Platzer Nicole , Beloeil Jean‐Claude , Doan Bich‐Thuy
Published: October 2002

Previous molecular modeling studies, in our laboratory, have shown that some esters of type RCOO(CH2)
nC5H5N+Cl− are potentially active against Alzheimer's disease. We have also demonstrated that acridine, which has strong anticholinesterase activity appears to be a suitable R substituent. The main obstacle to the possible pharmaceutical application of these compounds is their limited solubility in water, which is due to the poor aqueous solubility of acridine itself (0.26 mM). Inclusion complexation with cyclodextrins may overcome this problem. Solubility diagrams and NMR spectroscopy were used to study the inclusion of acridine (Acr) within β‐cyclodextrin (βCD) and heptakis(2,6‐di‐O‐methyl)cyclomaltoheptose (DMβCD). A 1:1 complex was formed for the Acr–βCD system and both 1:1 and 2:1 complexes for the Acr–DMβCD system (apparent Ka 215 ± 20 and 1150 ± 100 M
−1, respectively). Data from 1H NMR studies corrected the assignment of the acridine H1, H8 and H4, H5 protons in D2O, which have been erroneously assigned in previous publications. 1H spin–lattice relaxation times T1 measured with selective, non‐selective and null inversion characterize the dynamics of the inclusion complexes. Geometric features of the host–guest inclusion complexes were inferred from intermolecular dipolar interactions obtained by 2D adiabatic off‐resonance ROESY experiments. A more detailed picture of the structure of the inclusion complexes was obtained by combining NMR structural data and molecular modeling (docking, dynamics under NMR constraints and energy calculations). Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of nonlinear optical polyimides containing azodiamine derivative chromophores and their electrooptic and thermal properties
Authors: Zhou Yuming , Leng Weinan , Liu Xiaojuan , Xu Qunhua , Feng Jikang , Liu Juzheng
Published: October 2002

Some thermally stable second‐order nonlinear optical (NLO) polyimides were synthesized. The polyimides were prepared by the ring‐opening polyaddition of 4,4′‐(hexafluoroisopropylidene) diphthalic anhydride and pyromellitic dianhydride with two aromatic azodiamine derivatives as the NLO chromophores. These chromophores, based on a nitro group connected with azobenzene as the acceptor end of a donor–π‐bridge–acceptor chromophore and a diamine group as the donor end, had specific chemical stability. On the basis of ZERNER'S INDO methods, according to the sum‐over‐states formula, a program for the calculation of nonlinear second‐order optical susceptibilities was devised. The resulting polyimides had high number‐average and weight‐average molecular weights of up to 26,000 and 53,500, respectively, and a large glass‐transition temperature of 248 °C. With an in situ poling and temperature ramping technique, the optimal temperatures (Topt's) for corona poling were obtained for the largest second‐order NLO response. The electrooptic coefficient (γ33) of a polyimide at a wavelength of 830 nm was up to 21 pm/V after corona poling under its Topt, and the value remained at elevated temperatures (>90.6% was retained at 240 °C for >120 h). The thermal stability of the NLO polyimides was studied with UV spectrometry after poling of the films. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2478–2486, 2002
Photoimageable polyimides derived from α,α‐(4‐amino‐3,5‐dimethylphenyl)phenylmethane and aromatic dianhydride
Authors: Qian Z. G. , Pang Z. Z. , Li Z. X. , He M. H. , Liu J. G. , Fan L. , Yang S. Y.
Published: October 2002

Soluble and inherent photoimageable polyimides with improved photopatterning features were prepared from α,α‐(4‐amino‐3,5‐dimethylphenyl)phenylmethane and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride. The polyimides possessed good combined chemical and physical properties: thermal stability was observed, with an initial thermal decomposition temperature of 565 °C and a high glass‐transition temperature of 318 °C. Homogeneous polyimide solutions in common organic solvents with solid contents as high as 20 wt % were prepared. These solutions had a shelf life greater than 3 months. The polyimides had high electric insulating properties and low dielectric constants and dissipation factors. Fine patterns were processed by direct exposure of the polyimide coatings to UV i‐line, followed by development with an organic developer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3012–3020, 2002
Synthesis of fluorosilicone having highly fluorinated alkyl side chains based on the hydrosilylation of fluorinated olefins with polyhydromethylsiloxane
Authors: Furukawa Y. , Kotera M.
Published: October 2002

Hydrosilylation of fluorinated olefins with polyhydromethylsiloxane (PHMS) in the presence of a platinum catalyst was investigated to synthesize fluorosilicone having highly fluorinated alkyl side chains (Rf; CnF2n+1). The hydrosilylation of 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10‐heptadecafluoro‐1‐decene (C8F17CHCH2) (1) with poly(dimethylsiloxane‐co‐hydromethylsiloxane) {(CH3)3SiO[(H)CH3SiO]8[(CH3)2 SiO]18Si(CH3)3} (4) converted the hydrogen bonded to silicons into the 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10‐heptadecafluorodecyl group or fluorine bonded to silicons in the ratio of about 52:48, and the formation of the byproduct C7F15CFCHCH3 (8) was observed. The hydrosilylation of 7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,14‐heptadecafluoro‐4‐oxa‐1‐tetradecene (C8F17CH2CH2OCH2CHCH2) (2) with 4 converted the hydrogen bonded to silicons into the 7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,14‐heptadecafluoro‐4‐oxa‐tetradocyl group bonded to silicons, but an excess amount of 2 was required to complete the reaction because the isomerization of 2 occurred in part to form C8F17CH2CH2OCHCHCH3 (9). The hydrosilylation of 4,4,5,5,6,6,7,7,8,8,9,9, 10,10,11,11,11‐heptadecafluoro‐1‐undecene (C8F17CH2CHCH2) (3) with 4 converted the hydrogen bonded to silicons into the 4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11‐heptadecafluoroundecyl group bonded to silicons. This type of fluorinated olefin was successfully applied to the hydrosilylation with other PHMS's that involved a homopolymer of PHMS and a cyclic PHMS. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3120–3128, 2002
Morphology and physical properties of polyethylene/silicate nanocomposite prepared by melt intercalation
Authors: Wang Ki Hyun , Choi Min Ho , Koo Chong Min , Xu Mingzhe , Chung In Jae , Jang Min Cheol , Choi Sun Woong , Song Hyun Hoon
Published: October 2002

Maleated polyethylene (PEMA)/silicate nanocomposites with a different aspect ratio of silicate and maleated PEMA/SiO2 composite were prepared by melt intercalation. The nanocomposites with a high aspect ratio silicate (montmorillonite) showed a faster decrease in the terminal slope of the storage modulus and a steeper increase in complex viscosity than those with a low aspect ratio silicate (laponite) and SiO2. The addition of montmorillonite increases the crystallization and the melting temperature of PEMA but decreases above 3 vol % of the silicate content because of the increased viscosity. The nanocomposite with montmorillonite showed the highest yield strength and secant modulus among the composites because of the highest aspect ratio of the filler. It also revealed strong interfacial adhesion with the matrix and orientation during tensile deformation. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1454–1463, 2002
Dissolution and regeneration of cellulose in NaOH/thiourea aqueous solution
Authors: Zhang Lina , Ruan Dong , Gao Shanjun
Published: October 2002

A novel cellulose solvent, 1.5 M NaOH/0.65 M thiourea aqueous solution, was used to dissolve cotton linters having a molecular weight of 10.1 × 104 to prepare cellulose solution. Regenerated cellulose (RC) films were obtained from the cellulose solution by coagulating with sulfuric acid (H2SO4) aqueous solution with a concentration from 2 to 30 wt %. Solubility of cellulose, structure, and mechanical properties of the RC films were examined by infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, 13C NMR, and tensile tests. 13C NMR analysis indicated that the novel solvent of cellulose is a nonderivative aqueous solution system. The presence of thiourea enhanced significantly the solubility of cellulose in NaOH aqueous solution and reduced the formation of cellulose gel; as a result, thiourea prevented the association between cellulose molecules, leading to the solvation of cellulose. The RC film obtained by coagulating with 5 wt % H2SO4 aqueous solution for 5 min exhibited higher mechanical properties than that with other H2SO4 concentrations and a homogenous porous structure with a mean pore size of 186 nm for free surface in the wet state. The RC film plasticized with 10% glycerin for 5 min had a tensile strength of 107 MPa and breaking elongation of 10%, and about 1% glycerin in the RC film plays an important role in the enhancement of the mechanical properties. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1521–1529, 2002
Poly(vinylidene fluoride)/clay nanocomposites prepared by melt intercalation: Crystallization and dynamic mechanical behavior studies
Authors: Priya L. , Jog J. P.
Published: October 2002

The preparation and properties of poly(vinylidene fluoride) (PVDF)/clay nanocomposites are reported for the first time. PVDF/clay nanocomposites were prepared by melt intercalation with organophilic clay. The composites were characterized with X‐ray diffraction, differential scanning calorimetry, and dynamic mechanical analysis. X‐ray diffraction results indicated intercalation of the polymer into the interlayer spacing. PVDF in the nanocomposites crystallized in the β form. Differential scanning calorimetry nonisothermal curves showed an increase in the melting and crystallization temperatures along with a decrease in crystallinity, as evidenced by the melting and crystallization peaks. Isothermal crystallization studies showed an enhanced rate of crystallization with the addition of clay, as evidenced by a reduction in the crystallization time. Dynamic mechanical analysis indicated significant improvements in the storage modulus over a temperature range of −100 to 150 °C. The tan δ peak signifying the glass‐transition temperature of PVDF shifted to higher temperatures. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1682–1689, 2002