bluuebunny/crossref_metadata_2025 huggingface dataset:
Pregnancy‐related thrombosis in a woman with congenital afibrinogenemia: A report of two successful pregnancies
Authors: Roqué H. , Stephenson C. , Lee M.J. , Funai E.F. , Popiolek D. , Kim E. , Hart D.
Published: June 2004

We managed two pregnancies in a woman with congenital afibrinogenemia with increasing amounts of cryoprecipitate to achieve a pre‐infusion fibrinogen level of 60 mg/dL. The first pregnancy resulted in placental abruption at 36 weeks, in spite of recent cryoprecipitate infusion. Both placentas showed infarction. Post‐partum ovarian and renal vein thromboses complicated the second pregnancy. Mean FVIII (344%) and vWF Antigen (323%) were elevated prior to cryoprecipitate infusion, with mean post‐infusion levels of 367% and 363%. The clearance of fibrinogen after cryoprecipitate infusion increased during the course of pregnancy. A paradoxical prothrombotic state with embolization may play a role in the observed complications of pregnancy. Am. J. Hematol. 76:267–270, 2004. © 2004 Wiley‐Liss, Inc.
Echocardiographic abnormalities in sickle cell disease
Authors: Ahmed Shahid , Siddiqui Anita K. , Sadiq Adnan , Shahid Rabia K. , Patel Dilip V , Russo Linda A.
Published: June 2004

Echocardiographic abnormalities in patients with sickle cell disease (SCD) were determined, and pulmonary arterial systolic pressure (PASP) was estimated. Clinical data and echocardiograms of 38 adult hospitalized patients with SCD at two tertiary care hospitals were reviewed. Fisher's exact test was performed to determine correlation between pulmonary hypertension and various clinical variables. Pulmonary hypertension was the most common abnormality identified in 22 (58%) patients. The estimated mean PASP was 37.5 ± 10.9 mmHg. Older age and prior history of acute chest syndrome were significantly correlated with an increased prevalence of pulmonary hypertension (P < 0.05). Patients with hemoglobin levels <8 g/dL had PASP 43.2 ± 0.5 compared to a mean PASP of 33.3 ± 6.0 in patients with hemoglobin ≥8 g/dL (P = 0.01). Eight (21%) patients had evidence of a hyperdynamic left ventricle. Left heart abnormalities included dilated atrium in 14 (37%), dilated ventricle in 5 (13%), ventricle hypertrophy in 5 (13%), and ventricle dysfunction in 3 (9%) patients. Right heart abnormalities included dilated atrium in 9 (24%), dilated ventricle in 6 (16%), and ventricle dysfunction in 3 (9%) patients. Despite an increased incidence of abnormal flow across the valves on Doppler analysis, no patient had structurally abnormal valves. A majority of patients with SCD had evidence of pulmonary hypertension, which correlated with older age and history of acute chest syndrome. Other structural and functional echocardiographic abnormalities were less common. Am. J. Hematol. 76:195–198, 2004. © 2004 Wiley‐Liss, Inc.
Idiopathic light‐chain proteinuria: Case report and review of the literature
Authors: Audard Vincent , Damaj Ghandi , Rubio Marie Thérèse , Aucouturier Pièrre , Hermine Olivier , Varet Bruno
Published: June 2004

Isolated Bence Jones proteinuria (BJP) is a distinct form of monoclonal gammopathy of undetermined significance (MGUS) rarely described. The prognosis of the disease is apparently good. We report here a case of idiopathic BJP and review the literature. Am. J. Hematol. 76:293–294, 2004. © 2004 Wiley‐Liss, Inc.
Adaptive skills, cognitive, and behavioral characteristics of Costello syndrome
Authors: Axelrad Marni E. , Glidden Rochelle , Nicholson Linda , Gripp Karen W.
Published: June 2004

Costello syndrome is a rare congenital disorder whose diagnosis is based on clinical findings. The underlying genetic cause has not been identified. Common characteristics include failure to thrive, feeding problems, short stature, coarsening of facial features, developmental delay, mental retardation, skeletal problems, cardiac complications, and increased risk for solid tumors. Given its rarity, existing literature is limited regarding its natural course. Developmental milestones and intellectual functioning have never been systematically studied in this population, therefore this study focused on defining developmental and intellectual attributes. Data was obtained through solicited participation at the 3rd International Costello Syndrome Meeting. A total of 18 children (age 3–20 years) were administered the Leiter‐R brief‐IQ and the Peabody picture vocabulary test (PPVT)‐III to assess nonverbal cognitive functioning and receptive vocabulary. Parents/guardians completed the child behavior checklist (CBCL) and participated in an interview process to complete the survey form of the Vineland adaptive behavior scales to assess emotional/behavioral issues and adaptive behavior. Results indicated that nonverbal cognitive functioning ranged from 1.5 to 4.3 SD below the age mean. Receptive vocabulary skills ranged from average functioning to 4 SD below the age mean. Adaptive behavior composites were all in the low range (2.0 to >5.0 SD below age mean), however there was significant variability in the range of domain scores. CBCL results ranged from normal to clinically significant across various clinical parameters. These data support a generalized descriptive pattern of developmental delay and mental retardation, with noted variability in receptive language, level of adaptive behavior functioning, and emotional/behavioral aspects. Skills and behavior are compared to existing literature of children with various syndromes. © 2004 Wiley‐Liss, Inc.
Growth hormone deficiency in Costello syndrome
Authors: Stein Robert I. , Legault Laurent , Daneman Denis , Weksberg Rosanna , Hamilton Jill
Published: June 2004

We report on three patients with Costello syndrome and isolated growth hormone (GH) deficiency treated with biosynthetic GH. To our knowledge, these are the only patients with Costello syndrome who have been successfully treated for GH deficiency. We review the pathophysiology of Costello syndrome and highlight the recent recommendations of tumor screening and cardiac surveillance in this population, of particular relevance to those receiving GH therapy. © 2004 Wiley‐Liss, Inc.
Behavioral pattern profile: A tool for the description of behavior to be used in the genetics clinic
Authors: Shalev Stavit A. , Hall Judith G.
Published: June 2004

Careful descriptions of dysmorphic features have led to the delineation of hundreds of specific syndromes and patterns of congenital anomalies. The defining of unusual behavior had largely been neglected by clinical geneticists until the study of the natural history of microdeletions revealed that each has unique and characteristic behavior(s). In this study, a simple tool to describe behavior is presented that is to be used in the genetics clinic as part of routine evaluation. The form is meant to simplify recording and does not require the formal training needed for psychological assessments. It is hoped that routine recording of behavior among individuals seen in the genetics clinic will lead to better recognition of unusual behavior among individuals with known conditions, as well as the recognition of conditions characterized only by unusual behavior. Better description of behavioral patterns should lead to the ascertainment of homogeneous groups of affected individuals with abnormalities in the functional pathways that generate patterns of reaction. The genetic and biochemical basis for these patterns of reaction (abnormal behavior) should then be available for both natural history and molecular studies. The tool consists of 12 categories of behavioral features that can be assessed by the medical geneticist. The list was built to allow the observation of as many behavioral aspects as possible, but to keep it to a practical size and to use those features that are simple to describe and quantitate. We expect that its use will produce a rich source of behavioral profiles and will eventually contribute to the better understanding of unusual behavior. © 2004 Wiley‐Liss, Inc.
Katalytische Markownikow‐ und Anti‐Markownikow‐Funktionalisierung von Alkenen und Alkinen
Authors: Beller Matthias , Seayad Jayasree , Tillack Annegret , Jiao Haijun
Published: June 2004

Reaktionen zur selektiven Veredelung von Alkenen zählen zu den wichtigsten Methoden in der Organischen Synthese. Durch die Entwicklung von Übergangsmetallkatalysatoren in den letzten Jahrzehnten können heute alle Arten von Selektivität bei einer Vielzahl von Transformationen effizient gesteuert werden. Auch 100 Jahre nach dem Tod von Vladimir Markownikow – dem Pionier auf diesem Gebiet – ist die regioselektive Funktionalisierung von Alkenen und Alkinen immer noch ein wichtiges Forschungsziel: Besonders die Anti‐Markownikow‐Addition von Sauerstoff‐ und Stickstoff‐Nucleophilen an aliphatische Alkene und Alkine verfügt über großes industrielles Potenzial. In diesem Aufsatz werden neuere Entwicklungen auf diesem Gebiet beschrieben. Eine Auswahl aktueller Beispiele zeigt, wie die Regioselektivität durch die Wahl des Katalysators gesteuert werden kann.
Cover Picture: Palladium Oxidase Catalysis: Selective Oxidation of Organic Chemicals by Direct Dioxygen‐Coupled Turnover (Angew. Chem. Int. Ed. 26/2004)
Authors: Stahl Shannon S.
Published: June 2004

Environmentally friendly chemistry is often inspired by nature itself. This principle is portrayed in the cover picture depicting recent advances in the palladium‐catalyzed selective oxidation of organic molecules with molecular oxygen. In the Review on pp. 3400 ff., S. S. Stahl outlines the mechanistic principles and diversity of applications of “Palladium Oxidase Catalysis”. These catalytic reactions are reminiscent of enzymatic oxidases in which independent dioxygen reduction and substrate oxidation steps are coupled in a sequential, two‐stage mechanism.
Cartilage canals in the chicken embryo are involved in the process of endochondral bone formation within the epiphyseal growth plate
Authors: Blumer Michael J.F. , Longato Stefano , Fritsch Helga
Published: June 2004

A detailed study of so‐called communicating cartilage canals, which penetrate deeply up into the lower hypertrophic zone of the epiphyseal growth plate in the embryonic chicken femur (E20), was carried out with the aim to clarify whether or not these canals are involved in the bone‐forming process. In addition, we examined the manner in which cartilage canals are formed and compare the present data with our previous data. The canals were investigated by means of light microscopy, electron microscopy, immunohistochemistry (VEGF, VEGFR2/Flk1, type I collagen), and 3D reconstruction. Some communicating canals deeply penetrate into the upper hypertrophic zone where they terminate, showing electron‐dense cells at their end. Subcellular characteristics of these cells are hardly detectable and we suppose that they undergo cell death. Other canals pass down deeper into the lower hypertrophic zone. The upper segment of these canals is composed of capillaries, mesenchymal cells, and macrophage‐like cells. Precursors of osteoblasts are adjacent to the canals. The lower segment of communicating canals is composed of bone matrix or osteoid, which contains type I collagen fibrils and cells having the typical subcellular features of osteoblasts. No vessels are found in these segments. Immunohistochemistry shows that the matrix of the canals labels positively for type I collagen. In addition, staining with sirius red demonstrates that bone matrix is formed in these parts. We assume that the osteoblast‐like cells of the lower segments of communicating canals originate either from mesenchymal cells or even from hypertrophic chondrocytes. Our immunohistochemical data also reveal that vascular endothelial growth factor (VEGF) and the corresponding receptor VEGFR2/Flk1 (VEGF receptor 2/Flk1) are localized in cartilage canals of the reserve zone, the proliferative zone, and the hypertrophic zone. The receptor is found in the endothelial cells of the vessels. Furthermore, VEGF is present in hypertrophic chondrocytes. The results of our study suggest that cartilage canals penetrate actively into the cartilage anlage and that bone is formed in the lower segments of the communicating canals where no vessels are detectable. © 2004 Wiley‐Liss, Inc.
Detection of alkanes, alcohols, and aldehydes using bioluminescence
Authors: Minak‐Bernero Vera , Bare Richard E. , Haith Copper E. , Grossman Matthew J.
Published: June 2004

We report a novel method for the rapid, sensitive, and quantitative detection of alkanes, alcohols, and aldehydes that relies on the reaction of bacterial luciferase with an aldehyde, resulting in the emission of light. Primary alcohols with corresponding aldehydes that are within the substrate range of the particular luciferase are detected after conversion to the aldehyde by an alcohol dehydrogenase. In addition, alkanes themselves may be detected by conversion to primary alcohols by an alkane hydroxylase, followed by conversion to the aldehyde by alcohol dehydrogenase. We developed a rapid bioluminescent method by genetically engineering the genes encoding bacterial luciferase, alcohol dehydrogenase, and alkane hydroxylase into a plasmid for simultaneous expression in an E. coli host cell line. Alkanes, alcohols, or aldehydes were detected within seconds, with sensitivity in the micromolar range, by measuring the resulting light emission with a microplate reader. We demonstrate the application of this method for the detection of alkanes, alcohols, and aldehydes and for the detection of alkane hydroxylase and alcohol dehydrogenase activity in vivo. This method is amenable to the high‐throughput screening needs required for the identification of novel catalysts. © 2004 Wiley Periodicals, Inc.
Synergistic activity of Paenibacillus sp. BP‐23 cellobiohydrolase Cel48C in association with the contiguous endoglucanase Cel9B and with endo‐ or exo‐acting glucanases from Thermobifida fusca
Authors: Sánchez Marta M. , Irwin Diana C. , Pastor F.I. Javier , Wilson David B. , Diaz Pilar
Published: June 2004

Cellobiohydrolase Cel48C from Paenibacillus sp. BP‐23, an enzyme displaying limited activity on most cellulosic substrates, was assayed for activity in the presence of other bacterial endo‐ or exocellulases. Significant enhanced activity was observed when Cel48C was incubated in the presence of Paenibacillus sp. BP‐23 endoglucanase Cel9B or Thermobifida fusca cellulases Cel6A and Cel6B, indicating that Cel48C acts synergistically with them. Maximum synergism rates on bacterial microcrystalline cellulose or filter paper were obtained with a mixture of Paenibacillus cellulases Cel9B and Cel48C, accompanied by T. fusca exocellulase Cel6B. Synergism was also observed in cell extracts from recombinant clone E. coli pUCel9‐Cel48 expressing the two contiguous Paenibacillus cellulases Cel9B and Cel48C. The enhanced cellulolytic activity displayed by the cellulase mixtures assayed could be used as an efficient tool for biotechnological applications like pulp and paper manufacturing. © 2004 Wiley Periodicals, Inc.
Prognostic significance of both surgical and pathological assessment of curative resection for rectal cancer
Authors: Martling A , Singnomklao T , Holm T , Rutqvist L E , Cedermark B
Published: June 2004

Background

Information on whether surgery has been ‘curative’ is essential for prediction of prognosis and for selection of patients for adjuvant treatment. The aim of this study was to analyse the prognostic value of surgeons' and pathologists' assessments of tumour clearance in patients with primary rectal cancer who underwent resection.

Methods

A total of 1550 patients were studied prospectively. Data were collected from reports made by surgeons and pathologists on whether tumour clearance had been ‘complete’, ‘uncertain’ or ‘incomplete’. The predictive value in relation to outcome after at least 5 years of follow-up was assessed.

Results

In patients assessed as having a complete surgical clearance, tumour recurrence developed in 33·3 per cent. For patients with an uncertain or incomplete clearance the recurrence rate was 59·5 and 61 per cent respectively (P < 0·001). The relative risk of recurrence was twice as high when the surgeon and pathologist disagreed than when they both agreed on the complete clearance. Survival in patients with a complete, uncertain or incomplete surgical clearance was 55·3, 23·0 and 10 per cent respectively (P = 0·050).

Conclusion

Assessments of tumour clearance were of strong prognostic value in relation to outcome. When the surgeon or pathologist was uncertain, or there was disagreement about the completeness of clearance, the risk of recurrence was similar to that among patients in whom an incomplete resection had been performed.
Randomized clinical trial comparing conservative and surgical treatment of neurogenic faecal incontinence
Authors: Österberg A , Edebol Eeg-Olofsson K , Hålldén M , Graf W
Published: June 2004

Background

The treatment of choice in idiopathic (neurogenic) faecal incontinence is controversial. In a randomized study levatorplasty was compared with anal plug electrostimulation of the pelvic floor with respect to functional outcome and physiological variables.

Methods

Thirty-one patients underwent levatorplasty and 28 anal plug electrostimulation of the pelvic floor over 3 years. The results were evaluated at 3, 12 and 24 months after completion of treatment by means of a validated questionnaire and anorectal manometry and manovolumetry.

Results

Incontinence scores were significantly reduced during the entire observation period in both groups (P < 0·001) as was the use of pads (P = 0·003 to P < 0·001). The proportion of patients reporting improvement in physical and social handicap was greater in the levatorplasty group after 3, 12 and 24 months (P = 0·036 to P < 0·001). No significant changes in physiological variables were observed in either group.

Conclusion

Better results were obtained with levatorplasty than with anal plug electrostimulation of the pelvic floor in patients with idiopathic (neurogenic) faecal incontinence. Levatorplasty should be therefore be considered the treatment of choice for this condition.
Prospective survey of factors affecting risk discussion during consent in a surgical specialty
Authors: Pleat J M , Dunkin C S J , Davies C E , Ripley R M , Tyler M P H
Published: June 2004

Background

The Department of Health in the UK has developed new consent guidance but without clear recommendations on how the incidence and severity of a given risk should influence its discussion during the process of obtaining informed consent. Plastic surgery is a litigation-prone specialty that offers a paradigm for assessing attitudes to consent.

Methods

A questionnaire was sent to all surgeons at six plastic and reconstructive surgery units within the UK. It enquired what incidence of a relatively frequent minor severity risk such as wound infection, or an extremely rare but major risk such as stroke, would merit its discussion when obtaining informed consent for elective surgery.

Results

Sixty of 85 questionnaires were returned. For a minor risk, there was a consensus that an incidence threshold of 5 per cent or greater would necessitate its discussion. For a major risk, the modal threshold was 0·1 per cent, but there was a greater variability of response.

Conclusion

There was a wide variation of opinion as to how frequently a major risk must occur before it is likely to be conveyed to a patient during the process of consent. The findings suggest that recent change in case law has yet to disseminate fully in one surgical specialty, with the potential for the challenge that consent is not ‘informed’.
Surgical management of primary anorectal melanoma
Authors: Pessaux P , Pocard M , Elias D , Duvillard P , Avril M-F , Zimmerman P , Lasser P
Published: June 2004

Background

This aim of this study was to analyse outcome after surgery for primary anorectal melanoma and to determine factors predictive of survival.

Methods

Records of 40 patients treated between 1977 and 2002 were reviewed.

Results

Twelve men and 28 women of mean age 58·1 (range 37–83) years were included in the analysis. Overall and disease-free survival rates were 17 and 14 per cent at 5 years. Median overall survival was 17 months and disease-free survival was 10 months. The 5-year survival rate was 24 per cent for patients with stage I tumours, and zero for those with stage II or stage III disease. There was no significant difference in overall survival after wide local excision (49 and 16 per cent at 2 and 5 years respectively) and abdominoperineal resection (33 per cent at both time points). In patients with stage I and stage II disease, there was a significant association between poor survival and duration of symptoms (more than 3 months), inguinal lymph node involvement, tumour stage and presence of amelanotic melanoma.

Conclusion

Anorectal melanoma is a rare disease with a poor prognosis. Wide local excision is recommended as primary therapy if negative resection margins can be achieved.
Economic impact of laparoscopic versus open abdominal rectopexy
Authors: Salkeld G , Bagia M , Solomon M
Published: June 2004

Background

The introduction of new laparoscopic techniques has important cost implications. The aim of this study was to compare the cost effectiveness of laparoscopic rectopexy with that of open abdominal rectopexy for full-thickness rectal prolapse.

Methods

A cost effectiveness study was conducted alongside a randomized trial of laparoscopic versus open abdominal rectopexy.

Results

The efficacy trial demonstrated significant subjective and objective differences in favour of the laparoscopic technique. The mean operating time was 51 min longer for laparoscopic rectopexy than for the open procedure. Laparoscopic disposables incurred a mean cost of £291 per patient. The mean duration of hospital stay was significantly shorter for the laparoscopic group (P = 0·001). Laparoscopic rectopexy was associated with an overall mean cost saving of £357 (95 per cent confidence interval £164 to £592; P = 0·042) per patient.

Conclusion

Laparoscopic rectopexy is associated with superior clinical outcomes and is cheaper than the open approach.
Structure and unexpected chiroptical properties of chiral 4‐pyrrolidinyl substituted 2(5H)‐furanones
Authors: Gawroński Jacek , Gawrońska Krystyna , Kwit Marcin , Kacprzak Karol , Rychlewska Urszula
Published: June 2004

Planar 2(5H)‐furanones substituted at C4 with a chiral pyrrolidinyl group show CD spectra which are apparently due to the distortion of the C4‐N1 bond of sp2 character from the plane defined by the 2(5H)‐furanone ring atoms and/or due to the presence of substituents in the pyrrolidine ring. This is a new, previously not encountered structural factor determining the chiroptical properties of 2(5H)‐furanones and emerging from the analysis of X‐ray diffraction data and quantum mechanical DFT computations. In the presence of a C5 pseudoaxial substituent in the furanone ring, the sign of the furanone n–π* and π–π* transition Cotton effects is determined primarily by the previously postulated allylic helicity rule. Chirality 16:405–413, 2004. © 2004 Wiley‐Liss, Inc.
Concomitant versus sequential administration of epirubicin and paclitaxel as first‐line therapy in metastatic breast carcinoma
Authors: Conte Pier Franco , Guarneri Valentina , Bruzzi Paolo , Prochilo Tiziana , Salvadori Barbara , Bolognesi Angelo , Aldrighetti Daniela , Venturini Marco , Rosso Riccardo , Mammoliti Serafina , Carnino Flavio , Giannessi Piergiorgio , Costantini Massimo , Moyano Alfredo , Baldini Editta ,   on behalf of the Gruppo Oncologico Nord Ovest
Published: June 2004

BACKGROUND

The authors performed a randomized trial comprising patients with metastatic breast carcinoma (MBC). They used a noninferiority design to evaluate whether the results of sequential administration of epirubicin and paclitaxel were not markedly worse than the concomitant administration in terms of objective response rates (ORRs). Toxicity profile, quality of life (QOL), and pharmacoeconomic evaluations were evaluated as well.

METHODS

In the current study, 202 patients with MBC were randomized to receive either the combination of epirubicin at a dose of 90 mg/m2 plus paclitaxel at a dose of 200 mg/m2 for 8 cycles (concomitant arm, n = 108) or epirubicin at a dose of 120 mg/m2 for 4 cycles followed by paclitaxel at a dose of 250 mg/m2 over 3 hours for 4 cycles every 21 days (sequential arm, n = 94).

RESULTS

The authors rejected the null hypothesis that the sequential treatment is less active than the standard concomitant regimen (ORRs: concomitant = 58.5%, sequential = 57.6%). The median progression‐free and overall survival periods were 11.0 months (95% confidence interval [95% CI], 9.7–12.3) and 20.0 months (95% CI, 17.2–22.6), respectively, in the concomitant arm and 10.8 months (95% CI, 7.9–13.6) and 26 months (95% CI, 18.1–33.8), respectively, in the sequential arm (P = not significant). Patients who received the sequential regimen experienced a higher incidence of Grade 3/4 (according to the World Health Organization grading system) neutropenia (62.2% of courses vs. 50.62%; P = 0.003) and Grade ≥ 2 neuropathy (45.5% vs. 30.4% of patients; P = 0.03), whereas 6 patients who received the concomitant regimen developed Grade II cardiotoxicity according to New York Heart Association criteria. QOL analyses failed to provide clear differences.

CONCLUSIONS

The sequential administration of epirubicin and paclitaxel at full doses was found to be as active as their association. Therefore, both the sequential and the combined administration were acceptable options. Cancer 2004. © 2004 American Cancer Society.
Flow cytometric analysis of isolated liver mitochondria to detect changes relevant to cell death
Authors: Mattiasson Gustav
Published: June 2004

Background

Mitochondria are key players in many forms of cell death, and mitochondrial production of reactive oxygen species (ROS), membrane depolarization, permeability changes, and release of apoptogenic proteins are involved in these processes. Flow cytometric analysis of isolated mitochondria enables parallel analysis of mitochondrial structure and function in individual mitochondria, and small mitochondrial samples are sufficient for analysis. This article describes a well‐characterized protocol for flow cytometric analysis of isolated liver mitochondria that can be used to detect mitochondrial alterations relevant to cell death.

Methods

Fluorescent probes were used to selectively stain mitochondria (nonyl acridine orange), and to measure membrane potential (tetramethylrhodamine‐methyl‐ester, 1,1′,3,3,3′,3′‐hexamethylindodicarbocyanine‐iodide), as well as production of ROS (2′,7′‐dichlorodihydrofluorescein‐diacetate). Calcium‐induced mitochondrial swelling was detected as a decrease in SSC. To ensure optimal concentrations of all probes, the effect on mitochondrial respiration was evaluated.

Results

This protocol can be used to determine the purity of the mitochondrial preparation, to detect calcium‐induced morphological changes, small mitochondrial de‐ and hyperpolarizations, as well as physiological changes in ROS generation.

Conclusions

Flow cytometry is a very useful tool to simultaneously analyze several mitochondrial parameters that are important in the induction of mitochondria‐mediated cell death. © 2004 Wiley‐Liss, Inc.
Synthesis and Crystal Structure of Cs2(CN3H6)3[(C2H5)2NH2][W7O22(O2)2]·3H2O
Authors: Suzuki Hiroyuki , Hashimoto Masato , Okeya Seichi
Published: June 2004

A novel diperoxoheptatungstate was crystallised as a Cs+−CN3H6+−(C2H5)2NH2+ salt and characterised by a single‐crystal X‐ray diffraction method. The anion has a Lindqvist heptametallate structure. The metal atoms are located in a bent 2‐3‐2 arrangement with the central W3 section (W3, W4 and W5) as the hinge. The peroxo groups coordinate the tungsten atoms at both ends of the W3 section (W3 and W5). In the crystal polyanions, caesium and guanidinium cations, and water of crystallisation form tunnel‐like cavities, and the diethylammonium cations are accommodated in the cavities, suggesting a clathrate‐like feature for the compound. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Use of caesium‐137 data to evaluate SHETRAN simulated long‐term erosion patterns in arable lands
Authors: Norouzi Banis Y. , Bathurst J. C. , Walling D. E.
Published: June 2004

The caesium‐137 method of quantifying soil erosion is used to provide field data for validating the capability of the SHETRAN modelling system for predicting long‐term (30‐year) erosion rates and their spatial variability. Simulations were carried out for two arable farm sites (area 3–5 ha) in central England for which average annual erosion rates of 6·5 and 10·4 t ha−1 year−1 had already been determined using caesium‐137 measurements. These rates were compared with a range of simulated values representing the uncertainty in model output derived from uncertainty in the evaluation of model parameters. A successful validation was achieved in that the simulation range contained the measured rate at both sites, whereas the spatial variability was reproduced excellently at one site and partially at the other. The results indicate that, as the caesium‐137 technique measures the erosion caused by all the processes acting at a site, it is relevant to hydrologically based models such as SHETRAN only if erosion by wind, agricultural activities and other processes not represented in the model are insignificant. The results also indicate a need to reduce the uncertainty in model parameter evaluation. More generally, the caesium‐137 technique is shown to provide field data that improve the severity of the validation procedure (accounting for internal as well as outlet conditions) and that add spatial variability to magnitude as a condition for identifying unrealistic parameter sets when seeking to reduce simulation uncertainty. Copyright © 2004 John Wiley & Sons, Ltd.
An in vivo study of hydrogels based on physiologically clotted fibrin–gelatin composites as wound‐dressing materials
Authors: Noorjahan S.E. , Sastry T.P.
Published: June 2004

In this study we have reported the efficacy of three biomaterials: (a) physiologically clotted fibrin–gelatin composite (PFG), (b) PFG graft copolymerized with 2‐hydroxyethyl methacrylate (PFG–HEMA), and (c) PFG graft copolymerized with 2‐hydroxypropyl methacrylate (PFG–HPMA) as temporary wound‐dressing materials using the rat as an animal model. Full‐thickness excision wounds were made on the back of female rats weighing about 150 ± 10 g. The dressings were applied on the wounds and changed periodically at an interval of 4 days with the respective materials. The wounds treated with PFG–HEMA healed completely on 15th day after wound creation, whereas those treated with PFG and PFG–HPMA resulted in complete healing on the 17th day. The concentrations of collagen, hexosamine, and uronic acid in the granulation tissue were determined. The PFG and its graft copolymers acted as hydrogels, thereby absorbing excess exudates, while still maintaining a moist environment at the wound site. The enhanced wound healing in the experimental animals was reflected in the increased rate of wound contraction. The results of the histological and mechanical studies of the experimental groups revealed that reepithelialization and remodeling of the skin have been achieved by providing a moist environment at the wound site by the biomaterials and thereby hastening the migration of keratinocytes. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 305–312, 2004
Flexural strength of dental composite restoratives: Comparison of biaxial and three‐point bending test
Authors: Chung S. M. , Yap A. U. J. , Chandra S. P. , Lim C. T.
Published: June 2004

This study compared two test methods used to evaluate the flexural strength of resin‐based dental composites. The two test methods evaluated were the three‐point bending test4 and the biaxial flexural test. Materials used in this investigation were from the same manufacturer (3M ESPE) and included microfill (A110), minifill (Z100 and Filtek Z250), polyacid modified (F2000), and flowable [Filtek Flowable (FF)] composites. Flexural strength was determined with the use of both test methods after 1 week of conditioning in water at 37°C. Data were analyzed with the use of an ANOVA/Scheffé test and an independent‐samples t test at significance level 0.05. Mean flexural strength (n = 7) ranged from 66.61 to 147.21 and 67.27 to 182.81 MPa for three‐point bending and ball‐on‐three‐ball biaxial test methods, respectively. In both test methods, Z100 was significantly stronger than all other composites evaluated. In the three‐point bending test, flexural strength of Z250 was significantly higher than A110, F2000 and FF, and FF was significantly stronger than A110 and F2000. The biaxial test method arrived at the same conclusions except that there was no significant difference between Z250 and FF. Pearson's correlation revealed a significantly (p < 0.01) positive and good correlation (R2 = 0.72) in flexural strength between the two test methods. Although the biaxial test has the advantage of utilizing small specimens, the low reproducibility of this test method does not support the proposition that it is a more reliable test method when compared to the ISO three‐point bending test. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 278–283, 2004
Modelling of Cr(VI) removal from polluted groundwaters by ion exchange
Authors: Rivero María J , Primo Oscar , Ortiz M Inmaculada
Published: June 2004

This work reports the viability and modelling of the removal of Cr(VI) from polluted groundwaters by means of ion exchange using the resin Lewatit MP‐64. Feed groundwaters that contained Cr(VI) at an average concentration of 2431 mg dm−3 and 1187 mg dm−3 of chloride and 1735 mg dm−3 of sulfate as main anions were acidified to a pH of 2.0 prior to the removal process. Dynamic experiments were carried out in a fixed bed column with feed waters at flow rates in the range of 2.78 × 10−7 m3 s−1 to 5.55 × 10−7 m3 s−1. Regeneration was achieved with NaOH (2 mol dm−3). From the experimental results, the equilibrium of the ion exchange reaction was successfully modelled, obtaining an equilibrium constant (K′AB) = 44.90. Finally, a mass balance that included mass transfer resistances in the liquid and solid phases was developed and from the comparison between simulated and experimental data the value of the effective intraparticle diffusivity (Ds) was determined as 1.43 × 10−12 m2 s−1. Copyright © 2004 Society of Chemical Industry
Claw‐free 3‐connected P11‐free graphs are hamiltonian
Authors: Łuczak Tomasz , Pfender Florian
Published: June 2004

We show that every 3‐connected claw‐free graph which contains no induced copy of P11 is hamiltonian. Since there exist non‐hamiltonian 3‐connected claw‐free graphs without induced copies of P12 this result is, in a way, best possible. © 2004 Wiley Periodicals, Inc. J Graph Theory 47: 111–121, 2004
Micro Construction of Poly(ε‐caprolactone)/Poly(L‐lactic acid) Blend Film by Solution Casting under Microwave Irradiation
Authors: Jin Wei , Liu Lijian
Published: June 2004

Summary: The micro construction of poly(ε‐caprolactone) (PCL) and poly(L‐lactic acid) (PLLA) blend films fabricated by solution casting under microwave irradiation was investigated by selective enzymatic degradation and scanning electron microscopy (SEM).The results were totally different from the blends obtained by conventional methods. The blend was more homogeneous and the PCL continuous phase more compact as no spherulites and tiny zone separation were observed from the film surface and no PCL network was observed inside the film, and the degradation of a PCL plank by Pseudomonas lipase was significantly retarded. The distributed PLLA micro spheres were enlarged and amorphous. The thermal behavior of the blend by microwave heating revealed that PCL and PLLA underwent a melting process, which induced the variations of the PCL phase and PLLA spheres.

The weight loss caused by degradation of the PCL/PLLA blend obtained by conventional methods (B50c) is greater than that of the blend obtained by microwave methods (B50m), which reflects the change in morphology from a loose PCL network (B50c) to a dense PCL plank (B50m).

magnified image

The weight loss caused by degradation of the PCL/PLLA blend obtained by conventional methods (B50c) is greater than that of the blend obtained by microwave methods (B50m), which reflects the change in morphology from a loose PCL network (B50c) to a dense PCL plank (B50m).
Hydrogel Networks of Poly(ethylene oxide) Star‐Molecules Supported by Expanded Polytetrafluoroethylene Membranes: Characterization, Biocompatibility Evaluation and Glucose Diffusion Characteristics
Authors: Alexandre Eliane , Schmitt Bertrand , Boudjema Karim , Merrill Edward W. , Lutz Pierre J.
Published: June 2004

Summary: The present work discusses the grafting by electron beam irradiation of poly(ethylene oxide) (PEO) star‐shaped polymers onto porous expanded polytetrafluoroethylene (EXPTFE) surfaces. The resulting materials are intended to combine the good biocompatible properties of PEO with the outstanding mechanical properties of PTFE. The star‐shaped PEOs were synthesized via anionic polymerization. 3 Mev electron beam irradiation was applied to graft these PEO stars onto porous EXPTFE surfaces. The hydrophobic EXPTFE surface had to be pre‐modified with N‐vinylpyrrolidone. ESCA was used to quantify the amount of grafted star‐shaped PEO. Unmodified EXPTFE surfaces are well known, when implanted in a body, to be rapidly covered by a layer of cells and fibrin. The EXPTFE coated with PEO were implanted in the peritoneal cavity of rats (or under the back skin). This implantation did not induce any inflammation reactions and SEM analysis had attested the absence of adsorbed cells and fibrin. The glucose diffusion properties of these membranes were studied by a lag time analysis method and compared to those of pure PEO hydrogels. As expected, glucose diffuses through the hydrogel coated membrane and diffusion is not affected by the presence of the EXPTFE membrane.

EXPTFE surface before (left) and after (right) PEO hydrogel grafting.

magnified image

EXPTFE surface before (left) and after (right) PEO hydrogel grafting.
Cover Picture: Macromol. Mater. Eng. 6/2004
Authors: Bourbigot Serge , Le Bras Michel , Duquesne Sophie , Rochery Maryline
Published: June 2004

Cover: Intumescent structure obtained after burning poly(propylene) containing an intumescent formulation in the conditions of the limiting oxygen index (LOI) test.

Further details can be found in the Feature Article by S. Bourbigot,* M. Le Bras, S. Duquesne, and M. Rochery on page 499.
Carboplatin‐based chemotherapy for refractory and recurrent Ewing's tumours
Authors: Whelan Jeremy S. , McTiernan Anne , Kakouri Eleni , Kilby Anne
Published: June 2004

Background

Failure of first line therapy for the Ewing's family of tumours (EFT) is associated with a very poor outlook. Studies of second line chemotherapy are therefore necessary to identify active agents and drug combinations. Cisplatin‐based therapy is frequently used in these circumstances but there are few studies to clearly define activity and toxicity. This report details outcome in a cohort of patients with poor risk EFT treated with a carboplatin‐based combination.

Procedure

Between 1990 and 1998, 23 males and 16 females aged between 6 and 48 years (median 23) with relapsed or refractory EFT were treated with carboplatin‐based chemotherapy. Previous chemotherapy had included ifosfamide and doxorubicin in all but two patients. Twenty patients were treated at the time of recurrence, and 19 after a poor response to initial chemotherapy. Treatment comprised of carboplatin to give an area under the plasma carboplatin concentration versus time curve of (AUC) 6 mg/ml, etoposide 120 mg/m2 for 3 days, and cyclophosphamide 500–750 mg/m2 for 2 days, repeated every 21 days.

Results

A total of 105 cycles were given, median 2 per patient (range 1–5). Overall response was 26%, with one complete response and nine partial responses. Median time to progression was 10 weeks (range 2–54). Haematological toxicity was severe requiring dose reductions in 53% of patients. Six patients proceeded to high dose consolidation treatment with bone marrow or peripheral stem cell rescue.

Conclusions

This combination results in a substantial response rate in previously treated patients but with significant toxicity. Responses are, however, relatively short. © 2004 Wiley‐Liss, Inc.
Optical characterization of concentrated dispersions: applications to laboratory analyses and on‐line process monitoring and control
Authors: Buron H , Mengual O , Meunier G , Cayré I , Snabre P
Published: June 2004

Light scattering methods are often used to study the stability of suspensions or emulsions and to estimate the dispersed phase properties such as particle size and volume fraction. However, such optical methods often require a previous dilution of the dispersion because of a limited measurement range, and are then unable to give information about the real physical state of dense heterogeneous media. A new technology based on multiple light scattering analysis and called Turbiscan has been recently developed by a French company, Formulaction, to fill this gap and to characterize both diluted and concentrated dispersions. In the first part, we review the physical concepts of multiple light scattering by dispersions. In relation to the optical analyser Turbiscan, we present physical and statistical models for the radiative transfer in dense suspensions. In the second part, we investigate the influence of particle volume fraction and particle size (polystyrene latex bead suspensions) on the backscattered and transmitted light fluxes measured by Turbiscan. The experimental data are compared with results from the physical models. In the last section, we use the optical analyser Turbiscan Lab to detect and characterize various concentrated dispersions destabilization (coalescence, flocculation, creaming and sedimentation), and then the Turbiscan On Line to monitor and characterize an emulsification process under ultrasonic agitation. Copyright © 2004 Society of Chemical Industry
Characterization and properties of UV‐curable polyurethane‐acrylate/silica hybrid materials prepared by the sol‐gel process
Authors: Zhang Ling , Zeng Zhaohua , Yang Jianwen , Chen Yonglie
Published: June 2004

UV‐curable, transparent hybrid material of urethane‐acrylate resin was prepared by the sol‐gel process using 3‐(trimethoxysilyl)propylmethacrylate (TMSPM) as a coupling agent between the organic and inorganic phases. The effects of the content of acid and silica on the morphology and mechanical properties of UV‐curable polyurethane‐acrylate/silica hybrid (UA‐TMSPM)/SiO2 materials have been studied. The results of thermogravimetric analysis for the (UA‐TMSPM)/SiO2 hybrid materials indicated that the thermal stability of the hybrids is greatly improved. It was found that with the increase of HCl content, the interfacial interaction between organic and inorganic phases had been strengthened, as demonstrated by field emission scanning electron microscopy. Without sacrificing flexibility, the hybrid materials showed improved hardness with increasing content of acid and silica. Compared with the pure organic counterpart UA/hexanediol diacrylate (UA/HDDA) system, abrasion resistance of the hybrids improved with increasing acid content, at low silica content. Copyright © 2004 Society of Chemical Industry
Synthesis and characterisation of organosoluble polyimides containing the anisyl moiety
Authors: Ramalingam Hariharan , Sowrirajalu Bhuvana , Ganesan Anuradha , Muthusamy Sarojadevi
Published: June 2004

A new type of diamine monomer containing the anisyl moiety was synthesized via a straight‐forward one‐step procedure. Anisaldehyde was reacted with 2,6‐dimethylaniline in the presence of dry HCl to attain bis(4‐amino‐3,5‐dimethylphenyl)anisylmethane. A series of organo‐soluble polyimides were prepared using the anisyl diamine and various aromatic dianhydrides via a two step method involving thermal imidization. All polyimides are soluble in strong polar solvents such as N‐methyl‐2‐pyrollidone, N,N‐Dimethylformamide, and N,N‐DimethylAcetamide. The polyimides show excellent thermal stability and good mechanical properties. The glass transition temperatures of the polyimides are in the range 265–294 °C. The tensile strengths are in the range 79–99 MPa and the temperatures at which 10 % weight loss occurs are in the range 460–496 °C. Copyright © 2004 Society of Chemical Industry
Numerical simulation of the effect of nanotube orientation on tensile modulus of carbon‐nanotube‐reinforced polymer composites
Authors: Zhu Linjie , Narh Kwabena A
Published: June 2004

By correlating the curvature of carbon nanotubes to the orientation of fibers in a polymer, the effect of the curvature of nanotubes on the tensile modulus of carbon‐nanotube‐reinforced polymer composites was investigated with a numerical simulation method. The simulation results showed that the tensile modulus of a nanotube‐reinforced composite drops sharply when the nanotubes diverge from their orientation in the axial direction, and the presence of curved nanotubes in the polymer matrix significantly decreases the modulus of the composite. This finding could explain, partly, why in most cases, the predicted tensile modulus of a carbon‐nanotube‐reinforced composite, based on the assumption that the nanotubes are fully isolated and aligned in the polymer matrix, is much higher than the value obtained from experiments. Copyright © 2004 Society of Chemical Industry
Effect of aluminoxane on molecular weight and molecular weight distribution of polyethylene prepared by an iron‐based catalyst
Authors: Wang Qi , Li Lidong
Published: June 2004

A series of aluminoxanes, tetraethylaluminoxane (TEAO), tetraalkylaluminoxane (TAAO), Et2AlOB(4 − F − C6H4)OAlEt2 (BTEAO) and ethyl‐iso‐butylaluminoxane modified with p‐fluorophenylboric acid (BEBAO), were prepared and their effects on molecular weight (MW) and molecular weight distribution (MWD) of polyethylene prepared by the iron‐based catalyst [(ArNC(Me))2C5H3N]FeCl2 (Ar2,6‐dimethylphenyl) (1) were investigated. It was found that TEAO and BTEAO were highly efficient activators for iron‐based catalysts and introducing the branched bulky group (eg iso‐Bu) into the aluminoxane activator could improve the MW of the resulting polyethylene. The MW of polyethylene produced by activators modified by p‐fluorophenylboric acid was higher than for other aluminoxane activators. The TEAO‐ and TAAO‐based polyethylene exhibited attractive bimodal MWD, and the lower MW fraction of bimodal MWD was shown to be produced in the early stage of polymerization due to chain transfer to the aluminium activator. Copyright © 2004 Society of Chemical Industry
Zirconocene‐catalyzed copolymerization of methyl methacrylate with other methacrylate monomers
Authors: Karanikolopoulos Giorgos , Batis Christos , Pitsikalis Marinos , Hadjichristidis Nikos
Published: June 2004

Statistical copolymers of methyl methacrylate (MMA) with n‐butyl‐, s‐butyl, t‐butyl‐, n‐hexyl‐, decyl‐, stearyl‐, allyl‐, trimethylsilyl‐ and trimethylsilyloxyethyl methacrylate were prepared by zirconocene‐catalyzed copolymerization. The reactivity ratios of MMA copolymers with butyl‐, hexyl‐, and stearyl methacrylate were estimated using the Finemann–Ross, the inverted Finemann–Ross, and the Kelen–Tüdos graphical methods. Structural parameters of the copolymers were obtained from the calculated dyad sequences, derived by using the reactivity ratios. The effect of the nature of the methacrylate ester group and the catalytic system used on the copolymer structure is discussed. The glass‐transition temperature (Tg) values of MMA copolymers with butyl‐ and hexyl methacrylate were measured and examined in the frame of several theoretical equations, allowing the prediction of these Tg values. The best fit was obtained using Barton and Johnston equations, taking the monomer sequence distribution of the copolymers into account. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3761–3774, 2004