bluuebunny/crossref_metadata_2025 huggingface dataset:
Consistent selection of mutations in the 5′‐untranslated region of oral poliovirus vaccine upon passaging in vitro
Authors: Chumakov Konstantin M. , Dragunsky Eugenia M. , Norwood Laurie P. , Douthitt Monica P. , Ran Yuxin , Taffs Rolf E. , Ridge Jeanette , Levenbook Inessa S.
Published: March 2007

We have previously found that upon passaging type 3 oral poliovirus vaccine (OPV) in cell cultures the proportion of revertants at nucleotide 472 rapidly increases [Chumakov et al.: Proceedings of the National Academy of Sciences of the United States of America 88:199–203 1991]. Systematic study on the accumulation of these revertants showed that it was dependent on the multiplicity of infection and the temperature at which virus was grown. Revertants at position 472 of type 3 OPV accumulated faster in vaccines derived from Sabin Original (SO) substrain than from RNA‐plaque purified (RSO) substrain. The rate of accumulation of 472‐C revertants differed among cell lines and was higher in overgrown cell cultures suggesting that host factors are involved in the selection of mutants. We also found that accumulation of mutants occurred in vitro at position 480 in type 1 and position 481 in type 2 OPV, making the selection for revertants in domain F of the 5′‐noncoding region a general phenomenon for all three Sabin strains. Assessment of the abundance of these mutants may be used for evaluation of the quality of OPV lots. © 1994 Wiiey‐Liss, Inc.
Factors associated with viremia and elevated transaminase levels in asymptomatic hepatitis D virus‐infected risk groups
Authors: Wu Jaw‐Ching , Li Chin‐Shien , Chen Chih‐Li , Sheng Wen‐Yung , Lee Shou‐Dong , Lo Kwang‐Juei
Published: March 2007

To detect hepatitis D virus (HDV) RNA in asymptomatic HDV‐infected risk groups, Northern blot hybridization was carried out using a strand‐specific riboprobe. Univariate and multivariate analyses were carried out to evaluate factors associated with HDV viremia and elevated transaminase levels in these subjects. Two (15%) of 13 antibody to HDV (anti‐HDV) ‐positive intravenous drug addicts, 15 (33%) of 45 anti‐HDV positive prostitutes, and 6 (40%) of 15 anti‐HDV positive brothel goers had detectable serum HDV RNA. Older age (>31 years old) was negatively associated with HDV RNA (P < 0.04), while hepatitis B e antigen (HBeAg) was positively associated with it (P < 0.002) in univariate analysis. Only HBeAg was still significant in multivariate analysis (P < .05). Of the 76 asymptomatic anti‐HDV positive case, 28 (37%) had mildly elevated serum ALT levels and only 5 (7%) had ALT levels more than twice normal (>80 U/L). HBeAg (P < .05) and HDV RNA (P < .02) were two factors associated with ALT elevation in univariate analysis, and HDV RNA was the only significant factor in multivariate analysis (P < .005). In summary, active replication of HBV seemed to be of help for the assembly of HDV and viremia. However, active replication of HDV was associated mostly with mildly elevated ALT levels in these subjects. These cases may represent a particular group in the disease spectrum of HDV infection. © 1994 Wiiey‐Liss, Inc.
Prevalence of antibodies against hepatitis e virus among urban and rural populations in Venezuela
Authors: Pujol Flor H. , Favorov Michael O. , Marcano Teodardo , Esté José A. , Magris Magda , Liprandi Ferdinando , Khudyakov Yury E. , Khudyakova Natasha S. , Fields Howard A.
Published: March 2007

Antibodies against hepatitis E virus (HEV) were detected in sera by a synthetic peptide‐based enzyme immunoassay (EIA) from different populations in Venezuela. Antibodies against HEV were found in 1.6% (3/184) of urban pregnant woman (Caracas), in 3.9% (8/204) of rural populations (San Camilo, Edo Apure), and in 5.4% (12/223) of rural Amerindians (Padamo, Edo Amazonas). Positivity was confirmed by a neutralization EIA based on the use of competing soluble free pep‐tides. The prevalence of antibodies in the Amerindian group was significantly higher than in urban pregnant women. No relation was found between age and HEV prevalence in rural populations. Three of 21 positive sera were also weakly positive by Western blot for IgM antibodies. This result, together with the low optical density values observed by EIA, suggested that the presence of antibodies in these sera reflects past infections. Based on these results, Venezuela does not seem to be highly endemic for hepatitis E. This is the first report of serological evidence of infection by HEV in South America. © 1994 Wiley‐Liss, Inc.
Inhibition of human immunodeficiency virus type 1 replication by nonionic block polymer surfactants
Authors: Hirschman Shalom Z. , Zucker Marcia L. , Garfinkel Esther
Published: March 2007

Eight block copolymers of hydrophilic polyoxy‐ethylene and hydrophobic polyoxypropylene were examined for their effects on the replication of human immunodeficiency virus type 1 (HIV‐1) in H9 cells. Although the polymers decreased cellular replication, they did not appear to be toxic to the cells; rather, they seemed to arrest cellular growth. Three triblock copolymers were found to inhibit HIV replication at low concentrations. Maximum inhibition was achieved at concentrations of 50 μUg/ml by day 5 following infection. The combination of azidothymidine with both HIV‐1‐inhibitory and noninhibitory copolymers resulted in antagonistic effects, with an increase in viral replication, compared to treatment with copolymers or azidothymidine alone. These copolymers should be useful in the study of the mechanism of HIV replication in cell cultures and may yield clinically useful compounds in combination therapies for HIV infection. © 1994 Wiley‐Liss, Inc.
Detection of herpes simplex virus DNA sequences in human blood and bone marrow cells
Authors: Cantin Edouard , Chen Jian , Gaidulis Laima , Valo Zuzana , McLaughlin‐Taylor Elizabeth
Published: March 2007

Herpes simplex virus type 1 (HSV1) establishes latent infections in neural tissues of humans and experimental animals. Utilizing a sensitive polymerase chain reaction (PCR) assay we detected HSV DNA sequences in blood ceils of healthy prospective bone marrow transplant (BMT) donors and patients. In three healthy individuals studied, HSV DNA sequences were found in all blood cell types and also in bone marrow cells as well as in stem cell progenitor colonies isolated from in vitro cultures. Studies of BMT donor‐recipient pairs suggested that HSV reactivation may occur in hematopoietic cells after transplantation, as the PCR signal intensity increased over time simultaneous with an increased antibody liter to HSV. In a mouse model for HSV infection, HSV DNA sequences were found in blood and bone marrow cells at the latent stage of infection, after intravenous (IV) inoculation, but not after ocular inoculation. These studies suggest that bone marrow cells may be an additional site of HSV latency capable of reactivation after BMT. These studies have broad implications for understanding pathogenesis of HSV disease and are of particular significance in situations where allo‐geneic bone marrow cells are given therapeutically. © 1994 Wiley‐Liss, Inc.
Analysis of integrated hepatitis B virus DNA and flanking cellular sequences in a childhood hepatocellular carcinoma
Authors: Tsuei Daw‐Jen , Hsu Tsuey‐Ying , Chen Jen‐Yang , Chang Mei‐Hwei , Hsu Hey‐Chi , Yang Czau‐Siung
Published: March 2007

The DNA of tumor tissue K1 obtained at autopsy from a case of hepatocellular carcinoma (HCC) in a 9‐year‐old boy contained integrated hepatitis B virus (HBV) DNA at a single site in the chromosome (case 2, Chang et al.: Hepatology 13:316‐320, 1991). To characterize further the integrated viral DNA sequences, a genomic library of the K1 DNA was constructed in the lambda L47.1 vector. One phage clone, designated KTM‐1, containing integrated HBV DNA and cellular flanking sequences was obtained from this library. The restriction map and DNA sequence of this clone showed that the integrated HBV DNA was partially deleted and rearranged. The most conserved viral DNA sequences were surface and X genes and arranged in the opposite orientation. The viral core gene was not present. Using chloramphenicol acetyltransferase (CAT) assay, the C‐terminal truncated X open reading frame was demonstrated to retain its trans‐activating ability. The result suggested that the functional integrated X gene may play a role in hepatocarcinogenesis. The study also showed that the right cellular flanking sequences were human alphoid repetitive sequences. © 1994 Wiley‐Liss, Inc.
Oral famciclovir against duck hepatitis B virus replication in hepatic and nonhepatic tissues of ducklings infected in ovo
Authors: Tsiquaye Kwesi N. , Slornka Marek J. , Maung Mala
Published: March 2007

Detection of hepadnaviral DMA in extrahepatic tissues of human and animal models of hepatitis B virus (HBV) has raised the question of whether virus replication in organs other than the liver could be targeted for the treatment of chronic hepatitis B. Since duck hepatitis B virus (DHBV) replication is dynamic in the liver, kidney, pancreas, and spleen of newly hatched ducklings infected in ovo, we used the duck model and the new antiherpesvirus agent, famciclovir (FCV), to determine whether antiviral effect of nucleoside analogues on DHBV replication is pluripotential. Day‐old ducklings hatched from eggs laid by a DHBV‐carrier duck were bled and administered FCV (25 mg/kg/bd) orally for periods of 1, 2, 3, 6, 9, and 12 days. Seventeen (17) hours after the last dose of each regimen the duckling(s) was bled and postmortem samples of liver, kidney, pancreas, and spleen were snap‐frozen and stored at −70°. Analysis of plasma samples of ducklings treated for 2 days and longer by dot‐blot hybridisation showed that levels of DHBV DNA were reduced significantly compared to levels in samples collected before treatment begun. Southern blot hybridisation of tissue DNA corroborated these results and showed that DHBV DNA replicative intermediates in all the tissues examined were reduced to levels that reflected the amount of virus released into the blood of each treated duckling. It is concluded from these results that if antiviral agents could be transformed to active metabolites in any infected tissues including the liver, replication of hepadnaviruses would be inhibited. We also note that the ability of young ducklings to metabolise FCV to the parent compound, penciclovir, suggests that hatchlings could be used for screening antiviral compounds under development. © 1994 Wiley‐Liss, Inc.
Meningoradiculoneuritis due to acyclovir‐resistant varicella zoster virus in an acquired immune deficiency syndrome patient
Authors: Snoeck R. , Gérard M. , Sadzot‐Delvaux C. , Andrei G. , Balzarini J. , Reymen D. , Ahadi N. , De Bruyn J. M. , Piette J. , Rentier B. , Clumeck N. , De Clercq E.
Published: March 2007

Varicella zoster virus (VZV) is recognized as one of the major viral pathogens reactivated in patients with the acquired immune deficiency syndrome (AIDS). We report the case of meningora‐diculoneuritis in an AIDS patient, associated with the isolation in the cerebrospinal fluid (CSF) of a thymidine kinase (TK)‐deficient, acyclovir (ACV)‐resistant strain of VZV. Although the virus was sensitive in vitro to phosphonoformate (PFA), the patient did not improve during PFA therapy and finally died. Several VZV strains isolated from this patient (including two isolates from the patient's CSF) were analyzed for their TK activity and subsequently the viral TK gene was sequenced showing a major deletion leading to a truncated protein. Their susceptibility to several antiviral agents including ACV, PFA, (E)‐5‐(2‐bro‐movinyl)‐2′‐deoxyuridine (BVDU), 9‐β‐D‐ara‐binofuranosyladenine (vidarabine), (S)‐1‐(3‐hy‐droxy ‐ 2 ‐ phosphonylmethoxypropyl) cytosine (HPMPC), and (S)‐9‐(3‐hydroxy‐2‐phosphonyl‐methoxypropyl)adenine (HPMPA) was evaluated. All the virus strains isolated from this patient remained sensitive to HPMPA and HPMPC, pointing to the potential usefulness of these acyclic nucleoside phosphonates for the treatment of ACV‐resistant VZV infections in immunocom‐promised patients. © 1994 Wiley‐Liss, Inc.
Tumor suppressor genes, growth factor genes, and oncogenes in hepatitis B virus‐associated hepatocellular carcinoma
Authors: Tabor Edward
Published: March 2007

A series of changes in the genes that control hepatocyte growth, or interference with the protein products of these genes, appears to have an important role in the etiology of hepatocellular carcinoma (HCC). Mutations of the p53 tumor suppressor gene have been identified in 30‐50% of HCC patients in some geographic areas. Abnormalities of the RB tumor suppressor gene have been found in 20‐25% of HCCs, including 80‐86% of HCCs with p53 mutations. Overexpression of transforming growth factor α (TGF‐a), insulin‐like growth factor II (IGF‐II), and the oncogenes N‐ras, c‐myc, and c‐fos have been found in high percentages of HCC patients. The cumulative effect of these changes may be more important than the order in which they occur. Some of these changes may explain the mechanism(s) by which the hepatitis B virus participates in the development of HCC. © 1994 Wiley‐Liss, Inc.
Seroepidemiological associations between tuberculosis, malaria, hepatitis B, and AIDS in West Africa
Authors: Adebajo A. O. , Smith D. J. , Hazleman B. L. , Wreghitt T. G.
Published: March 2007

Serum samples from 51 patients with malaria, 35 patients with hepatitis B virus infection, 111 patients with tuberculosis, and 166 healthy controls were studied to determine any associations between tuberculosis, malaria, hepatitis B, and AIDS in Nigeria, West Africa. All serum samples were examined for the presence of HIV‐1/HIV‐2, hepatitis B virus surface antigen (HBsAg), and malaria antibodies.

Only one patient was HIV‐1 antibody‐positive and none HIV‐2 antibody‐positive. Statistical associations were found between the presence of malaria antibody litres on the one hand and a diagnosis of hepatitis B virus infection (P < 0.05) or tuberculosis (P < 0.05). A stronger association (P < 0.001) was found between the presence of HBsAg and tuberculosis suggesting that HBsAg carriers are at higher risk of contracting tuberculosis. © 1994 Wiley‐Liss, Inc.
New genotype of hepatitis C virus in South Africa
Authors: Ohno T. , Mizokami M. , Tibbs C. J. , Ohba K. , Suzuki K. , Wu R.‐R. , Nouri‐Aria K. T. , Williams Roger
Published: March 2007

Partial nucleotide sequences in the core region of the hepatitis C viral genome were determined by reverse transcription followed by polymerase chain reaction, in a patient with chronic hepatitis from South Africa. These nucleotide sequences showed a low degree of homology with known types of HCV: the degree of homology between the nucleotide sequences of these clones with HC‐J1, J4, J6, J7, Tr, and Eb‐1 were 86.1‐87.3%, 87.3‐87.9%, 83.0‐83.9%, 81.1‐82.0%, 81.0‐82.2%, and 82.8‐83.4%, respectively, and that the deduced amino acid sequence homologies between these clones and HC‐J1, J4, H6, J7, Tr, and Eb‐1 were 90.7‐91.6%, 89.7‐91.6%, 91.6‐93.5%, 90.7‐91.6%, 81.5‐82.4%, and 89.2‐90.2%, respectively. The nucleotide sequence homologies of these clones with HC‐J1, J4, J6, J7, Tr, and Eb‐1 were very low, compared to those between the same genotype. Further comparison using molecular evolutionary methods suggested that this sequence should be classified in a new genotype. © 1994 Wiley‐Liss, inc.
Expression of hepatitis B surface and core antigens and transforming growth factor‐a in “oval cells” of the liver in patients with hepatocellular carcinoma
Authors: Hsia Chu Chieh , Thorgeirsson Snorri S. , Tabor Edward
Published: March 2007

Recent studies have identified epithelial cell populations in human livers that are similar to the “oval cells” and “transitional cells” seen in rat livers during the early stages of chemical car‐cinogenesis. It has been suggested that these cells might be precursors of hepatocytes and theoretically could be involved in hepatocarcino‐genesis. The hepatitis B virus (HBV) also is believed to play a role in the etiology of hepatocellular carcinoma (HCC). Therefore, a study was conducted in nontumorous livers adjacent to HCCs obtained from 26 patients from China to determine whether HBV antigens could be identified in oval cells and transitional cells using an immunohistochemical technique. Hepatitis B surface antigen (HBsAg) was detected in the nontumorous livers of 22/26 (85%) patients. HBsAg was detected in oval cells in 18/26 (69%), in transitional cells in 21/26 (81%), and in mature hepatocytes in 22/26 (85%), but not in bile duct or ductule cells. Transforming growth factor‐α (TGF‐α) was expressed in oval cells, transitional cells, and bile duct cells in 24/26 (92%) patients, an in mature hepatocytes in 25/26 (96%). Coexpression of HBsAg and TGF‐α was identified in the same cells in populations of oval cells and transitional cells of selected patients. Because of the possibility that oval cells could be a source of evolving HCC, these findings suggest that expression of TGF‐α associated with HBV infection of oval cells could be a mechanism of human hepatocarcinogenesis. Thus, oval cells could be a site (or one of the sites) where HBV participates in the development of HCC. © 1994 Wiley‐Liss, Inc.
Avidities of IgG directed against viral capsid antigen or early antigen: Useful markers for significant epstein‐barr virus serology
Authors: Andersson Annika , Vetter Veronika , Kreutzer Ludger , Bauer Georg
Published: March 2007

Classical Epstein‐Barr virus (EBV) serology can be misleading in some cases due to the variability of the viral capsid antigen (VCA)‐IgM response, persistent or reactivated VCA‐IgM, or loss of anti‐EBNA‐1 during suppression of the cellular immune system. Therefore, we studied the usefulness and significance of avidity determinations of VCA‐IgG and EA‐IgG to achieve unequivocal interpretation of serological results.

Avidities of EBV capsid antigen‐specific IgG (VCA‐IgG) and early antigen‐specific IgG (EA‐IgG) were determined by indirect immunofluorescence during and after acute EBV infection. Low‐avidity antibodies were removed from antigen‐antibody complexes by incubation with 6 M urea for 3 minutes. The analysis of 105 sera taken at defined time spans with regard to the onset of clinical symptoms allowed us to determine the kinetics of maturation of avidity of VCA‐IgG. All sera had low‐avidity antibodies at the onset of disease. More than 90% of the sera showed an avidity index below 0.25 during the first 10 days after the onset of disease. Fifty percent of the sera exhibited an avidity index of 0.25 or above 20–30 days after the onset of clinical symptoms. Sera from past infections uniformly exhibited avidity indices of 0.5 or 1. Avidity of EA‐IgG may still be low when avidity of VCA‐IgG is already borderline or high, thus allowing further differentiation of acute and recent infections.

Avidity determination represents an important additional marker of serology in classical cases and allows diagnosis in aberrant cases, such as acute infections with low or undetectable VCA‐IgM. In convalescent patients with persistent or reactivated VCA‐IgM and in cases of negative anti‐EBNA‐1 due to a loss of this marker during immunosuppression, avidity determination of VCA‐IgG is helpful to prevent false diagnosis. © 1994 Wiley‐Liss, Inc.
Southern hybridisation analysis of HBV DNA in peripheral blood leucocytes and of different cell types: Changes during the natural history and with interferon‐α therapy in patients with hepatitis B virus infection
Authors: Catterall A. P. , Murray‐Lyon I. M. , Zuckerman A. J. , Harrison T. J.
Published: March 2007

Hepatitis B virus (HBV) DNA was evaluated in peripheral blood mononuclear cells (PBMC) from 50 individuals utilising Southern hybridisation analysis. HBV DNA sequences were detected in PBMC from 16/29 (55 percent) of chronic hepatitis B virus (HBV) carriers with serum HBeAg and HBV DNA, compared with 1/8 (13%) of carriers with anti‐HBe and HBV DNA negative (P = NS). Two of 7 patients with previous HBV infection and chronic liver disease had detectable HBV DNA in PBMC. Of the 19 patients with HBV DNA in PBMC, 18 had high molecular weight species. In addition, five of these had free, monomeric HBV DNA and six patients had low molecular weight bands. For nine of the above patients, total peripheral blood leucocytes were separated into PBMC and polymorphonuclear cells. Four had HBV DNA in PBMC only, two only in polymorphonuclear cells and three in both types of cell. Eleven patients with chronic HBV infection were studied at monthly intervals for 6 months. Six were untreated and five received IFN‐alpha. Three patients who responded to IFN‐a had HBV DNA present in PBMC before therapy, and two became negative. Two of 3 untreated patients had intermittent HBV DNA in PBMC and the other remained persistently negative. Of the patients positive on more than one occasion, the pattern of HBV DNA was similar. Peripheral blood leucocytes often contain multimers of free HBV DNA, more commonly in patients with serum HBeAg and HBV DNA and may occur even in the absence of serum HBsAg. These findings have implications for recurrence of disease after hepatic transplantation. HBV DNA in PBMC is detected intermittently over time and IFN‐α therapy may be associated with eradication. © 1994 Wiley‐Liss, Inc.
Raman and surface‐enhanced Raman spectra of flavone and several hydroxy derivatives
Authors: Teslova Tatyana , Corredor Charlie , Livingstone Richard , Spataru Tudor , Birke Ronald L. , Lombardi John R. , Cañamares M. V. , Leona Marco
Published: March 2007

The Raman and surface‐enhanced Raman spectra (SERS) of flavone and three of its hydroxy derivatives, 3‐hydroxyflavone (3‐HF) and 5‐hydroxyflavone (5‐HF) and quercetin (3,5,7,3′,4′ pentahydroxyflavone) have been obtained. The normal Raman (NR) spectra were taken in the powder form. The SERS spectra were obtained both on Ag colloids and Ag electrode substrates. Assignments of the spectrally observed normal modes were aided by density functional theory (DFT) calculations using the B3LYP functional and the 6‐31 + G* basis, a split valence polarized basis set with diffuse functions. Excellent fits were obtained for the observed spectra with little or no scaling. The most intense lines of the NR spectra are those in the CO stretching region (near 1600 cm−1). These lines are often weakened by proximity to the surface, while other lines at lower wavenumbers, due to in‐plane ring stretches, tend to be strongly enhanced. The SERS spectrum of flavone is weak both on the colloid and on the electrode, indicating weak attachment to the surface. In contrast, the SERS spectra of the hydroxy derivatives of flavone are intense, indicating the assistance of OH groups in attachment to the surface. The spectra of the various species are compared, and a case study of application to detection of a textile dye (Persian berries), which contains quercetin, is presented. Copyright © 2007 John Wiley & Sons, Ltd.
Advanced cooling technology for rotors of high‐power low‐duty cycle generators using polyalphaolefins
Authors: Sleiti Ahmad K.
Published: March 2007

Experimental and numerical studies of heat transfer distribution on rotors of high‐power low‐duty cycle electrical machines are performed to investigate the temperature distribution across the rotor core and winding insulation that determines the performance of rotor cooling techniques. Studies are performed to verify the selected cooling technique and coolant, and to determine the maximum heat load on the rotor and on the insulation material of the windings. The coolant used is polyalphaolefin (PAO) oil that can be used both as a coolant and lubricant. The boundary conditions investigated in this study are those existing on actual rotors of electric machines. The results show that the maximum temperature in the rotor conductors is found in the windings end turn and the maximum temperature in the insulation material of the rotor conductors could reach high values but still within the allowable maximum temperature limits. Copyright © 2007 John Wiley & Sons, Ltd.
Grease lubrication of rolling element bearings — role of the grease thickener
Authors: Cann P. M.
Published: March 2007

The contribution of grease thickener to lubricant film formation was examined in this paper. Lubricant film thickness and friction were measured for different grease thickener types in a bearing simulation device. The results showed that the greases formed thick (20–80nm), low friction surface layers at low speeds, which were much greater than the corresponding base oil film. These films appeared to be formed by the physical deposition of thickener in the track during overrolling of the grease. This was confirmed by infrared reflection analysis, which showed the deposited films to have increased thickener content. The ability of grease to form renewable physically deposited solid films has significant implications for optimising lubricant formulation for certain applications, e.g. bearings operating at high temperatures and low speeds where a conventional elastohydrodynamic lubricating film would be inadequate. Copyright © 2007 John Wiley & Sons, Ltd.
A impulsive infective transmission SI model for pest control
Authors: Zhang Hong , Xu Weijian , Chen Lansun
Published: March 2007

In this paper, we propose a model with impulsive control of epidemics for pest management. By using Floquet's theorem, small‐amplitude perturbation skills and comparison theorem, we show that there exists a globally asymptotically stable susceptible pest‐eradication periodic solution when the release amount of infective pests is larger than some critical value. However, when the amount of infective pests released is less than this critical value, the system is shown to be permanent, which implies that the trivial periodic susceptible pest‐eradication solution loses its stability. Further, the existence of a positive periodic endemic solution and other rich dynamics are also studied by numerical simulation. Therefore, we can use the amount of release of infective pests to control susceptible pests at desirable low levels. Copyright © 2007 John Wiley & Sons, Ltd.
Psychometric evaluation of the Spanish version of CONNECT: a measure of continuity of care in mental health services
Authors: Chavez L.M. , Canino G. , Shrout P.E. , Barrio C. , Ware N.C.
Published: March 2007

This article provides the results of the psychometric testing of the Spanish version of CONNECT(‐S), a measure of continuity of care in mental health services. CONNECT‐S is a multidimensional measure designed for use with seriously mentally ill respondents. Consisting of 12 scales and one single‐item indicator, it addresses qualities of interaction in current relationships between mental health service providers and consumers in five conceptual domains: (1) practitioner knowledge of their clients, (2) creating flexibility, (3) practitioner availability, (4) practitioner co‐ordination, and (5) smoothing transitions. One‐hundred‐and‐fifty participants took part in the study. Participants were recruited from mental health outpatient clinics in both the Puerto Rican (n = 109) and the San Antonio (n = 41) samples. Internal consistency for scales in a combined site estimate ranged from 0.68 to 0.96. Test‐retest reliability ranged from fair to substantial in all but one scale. Concurrent validity hypotheses based on a priori predictions were mostly supported. The Spanish translation and adaptation of CONNECT‐S provided sound psychometric results across both sites. CONNECT‐S addresses the gap in measurement of continuity of care for the two largest US Latino subgroups, Mexican Americans and Puerto Ricans; and provides an encouraging starting point for a measure that is both relevant and culturally sensitive. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of the value of the ICIQ‐UI SF questionnaire and stress test in the differential diagnosis of the type of urinary incontinence
Authors: Espuña‐Pons Montserrat , Dilla Tatiana , Castro David , Carbonell Cristina , Casariego Joaquín , Puig‐Clota Montserrat
Published: March 2007

Aims

Presently, there is no simple, universally accepted instrument for the initial diagnosis of urinary incontinence (UI), which is why physicians find it so difficult to integrate the diagnosis into their daily clinical practice. The objective of this study is to analyze the true value of the ICIQ‐UI SF questionnaire (ICIQ), the stress test, and the combination of both for the diagnosis as to the type of UI.

Methods

Cross‐sectional study performed in 116 women consulting for UI symptoms in two specialized health care centers. The subjects completed the ICIQ and underwent a stress test and urodynamic testing which was used for the reference diagnosis. Sensitivity, specificity, positive and negative predictive values, and the statistical “likelihood ratio (LR)” were assessed.

Results

According to the ICIQ, 45 women (38.8%) suffered from Stress UI (SUI); 19 (16.4%), Urgency UI (UUI), and 49 (42.2%), Mixed UI (MUI). According to the stress test, 75 (64.7%) presented SUI. According to the combination of both tests, the diagnosis was SUI in 35 (30.2%), UUI in 17 (14.7%), and MUI in 37 (31.9%). Regarding urodynamic testing, observations were as follows: USI in 45 subjects (38.8%), detrusor overactivity (DO) in 25 (21.6%), and combination of both (MUI) in 30 (25.9%). The combination of ICIQ‐UI SF plus stress test showed good specificity and negative predictive value, and the best LR coefficients obtained were: 3.11 (USI); 6.64 (UUI); 2.64 (MUI), and 3.77 (“all” SUI).

Conclusions

The combined use of the ICIQ plus stress test will aid in characterizing the type of UI at a basic health care level, favoring the prescription of the most appropriate treatment for each case. Neurourol. Urodynam. 26:836–841, 2007. © 2007 Wiley‐Liss, Inc.
Parameter uniform approximations for time‐dependent reaction‐diffusion problems
Authors: Linß Torsten , Madden Niall
Published: March 2007

Using discrete Green's functions techniques, we present a classification of fitted mesh methods for time‐dependent reaction diffusion problems, based on the analyses of Linß (Linß, Numer Algor 40 (2005), 23–32) for the analogous steady‐state problem and of Kopteva (Kopteva, Computing 66 (2001), 179–197) for time‐dependent convection‐diffusion problems.

As examples of how to apply the analysis, we derive error estimates for the fitted meshes of Shishkin and Bakhvalov, and provide supporting numerical results. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007
Incremental unknowns preconditioning for solving the Helmholtz equation
Authors: Poullet Pascal , Boag Amir
Published: March 2007

An efficient preconditioner is developed for solving the Helmholtz problem in both high and low frequency (wavenumber) regimes. The preconditioner is based on hierarchical unknowns on nested grids, known as incremental unknowns (IU). The motivation for the IU preconditioner is provided by an eigenvalue analysis of a simplified Helmholtz problem. The performance of our preconditioner is tested on the iterative solution of two‐dimensional electromagnetic scattering problems. When compared with other well‐known methods, our technique is shown to often provide a better numerical efficacy and, most importantly, to be more robust. Moreover, for the best performance, the number of IU levels used in the preconditioner should be designed for the coarsest grid to have roughly two points per linear wavelength. This result is consistent with the conventional sampling criteria for wave phenomena in contrast with existing IU applications for solving the Laplace/Poisson problem, where the coarsest grid comprises just one interior point. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007
A second‐order linearized difference scheme for a strongly coupled reaction‐diffusion system
Authors: Cao Hai‐Yan , Sun Zhi‐Zhong
Published: March 2007

This article deals with the numerical solution to some models described by the system of strongly coupled reaction–diffusion equations with the Neumann boundary value conditions. A linearized three‐level scheme is derived by the method of reduction of order. The uniquely solvability and second‐order convergence in L2‐norm are proved by the energy method. A numerical example is presented to demonstrate the accuracy and efficiency of the proposed method. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007
Preimplantation genetic diagnosis for cancer predisposition syndromes
Authors: Spits C. , De Rycke M. , Van Ranst N. , Verpoest W. , Lissens W. , Van Steirteghem A. , Liebaers I. , Sermon K.
Published: March 2007

Objectives

Mutations in the APC, NF2 and BRCA1 genes cause adult‐onset cancer predisposition syndromes. Prenatal diagnosis (PND) and selective pregnancy termination for adult‐onset disorders is emotionally difficult and, in some cases, socially not well accepted. Preimplantation genetic diagnosis (PGD) appears as an attractive alternative to PND, as it ensures the establishment of a pregnancy free of the mutation from the onset, circumventing the potentially difficult decision of termination of pregnancy.

Methods

Development of single‐cell PCRs using Epstein‐Barr virus transformed lymphoblasts as single‐cell model, followed by clinical application in PGD.

Results

A total of five duplex‐PCRs were developed, three for adenomatous polyposis of the colon (APC), one for neurofibromatosis type 2 (NF2) and one for inherited breast and ovarian cancer caused by BRCA1 mutations. Eleven clinical cycles were performed, resulting in the birth of an unaffected girl. For one of the couples undergoing PGD for NF2, a spontaneous pregnancy ensued after five unsuccessful PGD cycles. The couple underwent chorionic villus sampling (CVS) and the application of the same protocol as used during PGD showed an unaffected fetus.

Conclusion

In this work, we present the development and clinical application of PGD for three cancer predisposition syndromes. Copyright © 2007 John Wiley & Sons, Ltd.
Micromechanical approach to modeling damage in crystalline polyethylene
Authors: Alvarado‐Contreras José , Polak Maria Anna , Penlidis Alexander
Published: March 2007

The purpose of this article is to describe how the concepts of continuum damage mechanics can be applied to modeling of polyethylene materials under different loading conditions. The increasing use of polyethylene in diverse applications motivates the need for understanding how its molecular properties relate to the overall behavior of the material. Although microstructure and mechanical properties of polymers have been the subject of several studies, the irreversible microstructural rearrangements occurring at large deformations are not completely understood. In this work, a three‐dimensional damage constitutive model for polyethylene is proposed. The material is analyzed from a microscopic viewpoint and considered as an aggregate of crystals. The model regards the crystals as rigid‐viscoplastic and incorporates the effects of atomic debonding on the overall mechanical behavior. To illustrate the capability of the proposed model, two simulations are carried out to capture the macroscopic stress–strain behavior and texture evolution under uniaxial tension and simple shear loading conditions. The results are compared with experimental data and numerical simulations from other references. POLYM. ENG. SCI., 47:410–420, 2007. © 2007 Society of Plastics Engineers.
Polyolefins–biofibre composites: A new way for an industrial production
Authors: Soulestin J. , Quiévy N. , Sclavons M. , Devaux J.
Published: March 2007

Low density polyethylene (LDPE) composites based on cellulose fibres have been processed by high shear extrusion with water injection to help dispersion of fibres and release nanofibres from cellulose. Influence of extrusion parameters as shear, residence time, storage conditions of the matrix, and effect of water injection on the morphological properties of the composites have been studied using microscopy. Optimization of the extrusion parameters is necessary to reach a dispersion of the fibres. Increasing shearing forces and residence time allows limiting the presence of large aggregates of cellulose fibres. Use of powdered LDPE, even for short residence time and low shear, is efficient to produce well‐dispersed composites. Injection of water during the extrusion also improves the quality of the dispersion. However, no nanofibres are observed. The main effect is a spectacular decrease of the discoloration (yellowing) due to cellulose degradation. Mechanical properties of the composites have been investigated. Young modulus increases with cellulose content and reinforcing effect is more important above 10% by weight. For well‐dispersed composites, the extrusion parameters have no significant influence on the stiffness of the composites. However, due to the weakness of the interface, the ductility of composites is reduced compared with LDPE. POLYM. ENG. SCI., 47:467–476, 2007. © 2007 Society of Plastics Engineers.
Solid‐state structure and formation of organized molecular films of methacrylate copolymers containing fluorinated and hydrogenated side‐chains
Authors: Fujimori Atsuhiro , Kobayashi Satoshi , Hoshizawa Hiroko , Masuya Ryosuke , Masuko Toru
Published: March 2007

Surface morphology of monolayers related to solid‐state structure for methacrylate comb copolymers having fluorocarbon and hydrocarbon side‐chains was investigated by X‐ray diffraction (XRD), differential scanning calorimetry, and atomic force microscopy (AFM). From the XRD profiles, two kinds of short spacing peaks were confirmed at 5.0 and 4.2 Å, which assigned the sub‐cells for both side‐chains. Furthermore, two kinds of endothermic peaks, which corresponded to melting peaks of the both side‐chain crystals, appeared in the thermograms. From the AFM observation, it was found that there were hydrogenated domains at a few hundred nanometer diameter in their monolayers, whereas corresponding acrylate copolymer monolayers form the phase‐separated structure at 10–30 nm order scales. POLYM. ENG. SCI., 47:354–364, 2007. © 2007 Society of Plastics Engineers.
Effect of uniaxial drawing of soy protein isolate biopolymer film on structure and mechanical properties
Authors: Kurose Takashi , Urman Kevin , Otaigbe Joshua U. , Lochhead Robert Y. , Thames Shelby F.
Published: March 2007

The effect of uniaxial drawing of biodegradable soy protein isolate (SPI) polymer film on mechanical properties was investigated to accelerate the efforts to develop SPI films with improved properties. The films containing 0–30 wt% glycerol were drawn uniaxially up to a draw ratio of 2.5. The mechanical properties of the SPI film increased significantly after uniaxial drawing. The tensile strength of the undrawn film (49.7 MPa) was approximately doubled by subjecting the film to uniaxial drawing to a D.R. of 2.5. Wide‐angle X‐ray diffraction and differential scanning calorimetry measurements did not show evidence of generation of a crystal phase in the drawn SPI films. ATR‐FTIR revealed that the protein film contained mainly α‐helix and β‐sheets secondary structures. Microwave molecular orientation analysis showed that birefringence increased with increasing draw ratios. Mechanical anisotropy of the SPI film via orientation of α‐helix and β‐sheets structure is thought to be responsible for the enhancement of mechanical properties with uniaxial drawing of the SPI films. POLYM. ENG. SCI., 47:374–380, 2007. © 2007 Society of Plastics Engineers.
Effects of processing parameters on the filament fiber diameter of spunbonded nonwoven fabrics
Authors: Bo Zhao
Published: March 2007

The air drawing model of polymer in spunbonding is established. The air drawing model of polypropylene polymer in spunbonding is confirmed by the experimental results obtained with the help of our university's equipment. The predicted filament fiber diameter is in accordance with the experimental data. The effects of the process parameters on the filament fiber are investigated in this article. It is found that a lower polymer throughput rate, a higher polymer melt temperature, a higher primary air temperature, a higher air suction speed, a higher quench pressure, a higher venturi gap can all yield finer fiber, whereas the effect of the web basis weight is not significant. The results show great prospects for this research in the field of computer assisted design of spunbonding technology. POLYM. ENG. SCI., 47:510–515, 2007. © 2007 Society of Plastics Engineers.
Dendrimers as drug delivery vehicles: non‐covalent interactions of bioactive compounds with dendrimers
Authors: Crampton Hannah L , Simanek Eric E
Published: March 2007

This mini review highlights issues associated with the use of dendrimers as drug delivery vehicles. The review introduces dendrimers and summarizes findings on their use in vivo and in vitro. Specifically, this review is limited to examples wherein the drug is non‐covalently associated with the dendrimer. Examples wherein the drug is covalently attached to the dendrimer are not discussed. Copyright © 2007 Society of Chemical Industry
Preparation of gradient copolymers via ATRP in miniemulsion. II. Forced gradient
Authors: Min Ke , Kwon Oh Jung , Matyjaszewski Krzysztof
Published: March 2007

A series of forced gradient copolymers with different controlled distribution of monomer units along the copolymer backbone were successfully prepared by atom transfer radical polymerization in miniemulsion. The newly developed initiation technique, known as activators generated by electron transfer, was beneficial for forced gradient copolymers preparation because all polymer chains were initiated within the miniemulsion droplets and the miniemulsion remained stable throughout the entire polymerization. Various monomer pairs with different reactivity ratios were examined in this study, including n‐butyl acrylate/t‐butyl acrylate, n‐butyl methacrylate/methyl methacrylate, and n‐butyl acrylate/styrene. In each case, the added monomer diffused across the aqueous suspending medium and gradient copolymers with different forced distributions of comonomer units along the polymer backbone were obtained. The shape of the gradient along the backbone of the copolymers was influenced by the molar ratio of the monomers, the reactivity ratio of the comonomers as well as the feeding rate. The shape of the gradient was also affected by the relative hydrophobicities of the comonomers. Copolymerizations exhibited good control for all feeding rates and comonomer feeding ratios, as evidenced by narrow molecular weight distribution (Mw/Mn = 1.20–1.40) and molecular weight increasing smoothly with polymer yield, indicating high initiation efficiency. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1413–1423, 2007
Biodegradation of plasticized poly(vinyl chloride) containing cellulose
Authors: Kaczmarek Halina , Bajer Krzysztof
Published: March 2007

The plasticized poly(vinyl chloride) (PVC‐P) and its blend with cellulose (PVC‐P/cell) were prepared by means of extrusion. The samples were then biodegraded in forest soil as well as in soil enriched with cellulolytic microorganisms. Moreover, the samples were vaccinated with chosen species of fungi whose direct effect on polymer was then observed. The course of biodegradation was monitored in terms of, and by means of the following: weight loss, carbon dioxide evolved, attenuated total reflectance infrared (FTIR‐ATR) spectroscopy, gel permeation chromatography (GPC), as well as visual and microscopic observation (OM, SEM). The mechanical properties of samples were studied using the standard tensile tests. It was found that biodegradation in soil occurs in PVC‐P and this process is accelerated in the composition of PVC‐P with cellulose. The biodecomposition yield of PVC‐P/cellulose blends (calculated as relative percentage weight loss) is several dozen times higher than that of PVC‐P. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 903–919, 2007
New insights into the cold crystallization of filled natural rubber
Authors: Chenal J. M. , Chazeau L. , Bomal Y. , Gauthier C.
Published: March 2007

This article is devoted to the cold crystallization of filled natural rubber with different types of filler such as carbon black, silica, and grafted silica. A large set of differential scanning calorimetry data is presented with various scanning rates, times, and temperatures of isothermal crystallization to display the factors affecting natural rubber (NR) crystallization. The crystallization kinetic measurements suggest that fillers can create a region with perturbed mobility where the kinetics of nucleation and/or growth are slowed down, the rest of the matrix being unperturbed. And, the final crystallization level indicates the existence of an excluded region for crystallization close to the filler surface. Furthermore, the presence of fillers appears less unfavorable to NR crystallization than chemical crosslinking. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 955–962, 2007
New nanohybrids of poly(ε‐caprolactone) and a modified Mg/Al hydrotalcite: Mechanical and thermal properties
Authors: Pucciariello Rachele , Tammaro Loredana , Villani Vincenzo , Vittoria Vittoria
Published: March 2007

Novel composites based on poly(ε‐caprolactone) (PCL) and an organically modified layer double hydroxide (LDH) obtained using the melt‐extrusion technique have been characterized through structural, thermal, and mechanical analyses. Although exfoliation has not been achieved and despite the very low content of filler (from 1 to 3% by weight), significant enhancements are obtained in the physical and mechanical properties of the composites with respect to neat PCL. As a consequence, LDHs can substitute other nanofillers, in particular, cationic clays for polymeric matrices. They can be modified by a large number of organic anions, generally more numerous than the cationic ones, and can be mixed in very simple ways with polymers. This makes such nanofillers suitable to obtain new hybrid materials for a series of applications, from active food packaging to intelligent materials for biomedical device, for example, controlled drug release. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 945–954, 2007
Restraining the aggregation of photoluminescent 1‐pyrenecarboxylic acid by hydrogen bonding to poly(methyl methacrylate)
Authors: Su Fu‐Kun , Liau Guei‐Fen , Hong Jin‐Long
Published: March 2007

Hydrogen bonds between the carboxylic acid in photoluminescent 1‐pyrenecarboxylic acid (PCA) and the ester carbonyl group in poly(methyl methacrylate) (PMMA) can be used to restrain the aggregation of the fluorescent PCA molecules and to enhance the emission efficiency of the resulting PMMA/PCA films. Primarily, PCA is added to PMMA in THF (or in toluene) to make homogeneous mother solutions for the further preparation of solid PMMA/PCA films. The concentration and chain conformation of PMMA in the mother solution are crucial to controlling the dispersion of PCAs in solution and, therefore, the extent of aggregation in the so‐derived films. The results from solution emissions suggest that PCAs in dilute solutions are easy to disperse, and less PMMA is required for the effective exclusion of aggregation in comparison with PCAs in concentrated solutions. In addition, the solvents THF and toluene play different roles in the arrangement of the PMMA chains and the emission behavior of the incorporated PCA in the dilute and semidilute regimes. With appropriate solution preparation conditions, the resulting films have photoluminescence quantum efficiencies ranging from 0.83 to 0.93, and the best value of 0.93 has been obtained from a film containing a small PCA content of 0.24 wt %. This result indicates that the fluorophore arrangements, rather than the content, govern the final emission efficiency. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 920–929, 2007