bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of gankyrin protein expression with early clinical stages and insulin-like growth factor-binding protein 5 expression in human hepatocellular carcinoma
Authors: Umemura Atsushi , Itoh Yoshito , Itoh Katsuhiko , Yamaguchi Kanji , Nakajima Tomoki , Higashitsuji Hiroaki , Onoue Hitoshi , Fukumoto Manabu , Okanoue Takeshi , Fujita Jun
Published: December 2007

Gankyrin (also known as PSMD10) is a liver oncoprotein that interacts with multiple proteins including MDM2 and accelerates degradation of the tumor suppressors p53 and Rb. We produced a monoclonal anti-gankyrin antibody and immunohistochemically assessed the clinicopathological significance of gankyrin overexpression in 43 specimens of human hepatocellular carcinoma (HCC). Specific cytoplasmic staining for gankyrin was observed in 62.8% (27/43) of HCCs, which was significantly associated with low TNM stage (

P

= 0.004), no capsular invasion (

P

= 0.018), no portal venous invasion (

P

= 0.008), and no intrahepatic metastasis (

P

= 0.012). The cumulative survival rate of patients with gankyrin-positive HCC was significantly higher than that with gankyrin-negative HCC (

P

= 0.037). p53 and MDM2 were positively stained by antibodies in 30.2% and 23.3%, respectively, of HCCs, but neither was inversely associated with gankyrin expression. In the Huh-7 human HCC cell line, overexpression of gankyrin up-regulated expression of insulin-like growth factor binding protein 5 (IGFBP-5), whereas suppression of gankyrin expression by siRNA down-regulated it. Supression of IGFBP-5 expression inhibited proliferation of Huh-7 cells as well as U-2 OS osteosarcoma cells. In HCC specimens, positive staining for IGFBP-5 was observed by immunohistochemistry in 41.9% (18/43), and the level of expression was significantly correlated with that of gankyrin (

rho

= 0.629,

P

< 0.001).

Conclusion:

These results suggest that gankyrin plays an oncogenic role(s) mainly at the early stages of human hepatocarcinogenesis, and that IGFBP-5 inducible by gankyrin overexpression may be involved in it. (Hepatology 2008.)
Etiology-dependent molecular mechanisms in human hepatocarcinogenesis
Authors: Schlaeger Christof , Longerich Thomas , Schiller Claudia , Bewerunge Peter , Mehrabi Arianeb , Toedt Grischa , Kleeff Jörg , Ehemann Volker , Eils Roland , Lichter Peter , Schirmacher Peter , Radlwimmer Bernhard
Published: December 2007

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and is characterized by aggressive tumor behavior coupled with poor prognosis. Various etiologies have been linked to HCC development, most prominently chronic hepatitis B and C virus infections as well as chronic alcohol consumption. In approximately 10% of HCCs, the etiology remains cryptic; however, recent epidemiological data suggest that most of these cryptogenic HCCs develop due to nonalcoholic steatohepatitis. To identify etiology-dependent DNA copy number aberrations and genes relevant to hepatocarcinogenesis, we performed array-based comparative genomic hybridization of 63 HCCs of well-defined etiology and 4 HCC cell lines followed by gene expression profiling and functional analyses of candidate genes. For a 10-megabase chromosome region on 8q24, we observed etiology-dependent copy number gains and

MYC

overexpression in viral and alcohol-related HCCs, resulting in up-regulation of

MYC

target genes. Cryptogenic HCCs showed neither 8q24 gains, nor

MYC

overexpression, nor target gene activation, suggesting that tumors of this etiology develop by way of a distinct

MYC

-independent pathomechanism. Furthermore, we detected several etiology-independent small chromosome aberrations, including amplification of

MDM4

on 1q32.1 and frequent gains of

EEF1A2

on 20q13.33. Both genes were overexpressed in approximately half the HCCs examined, and gene silencing reduced cell viability as well as proliferation and increased apoptosis rates in HCC cell lines.

Conclusion:

Our findings suggest that

MDM4

and

EEF1A2

act as etiology-independent oncogenes in a significant percentage of HCCs. (Hepatology 2008.)
Natural antisense transcript stabilizes inducible nitric oxide synthase messenger RNA in rat hepatocytes
Authors: Matsui Kosuke , Nishizawa Mikio , Ozaki Takashi , Kimura Tominori , Hashimoto Iwao , Yamada Masanori , Kaibori Masaki , Kamiyama Yasuo , Ito Seiji , Okumura Tadayoshi
Published: December 2007

During inflammation, inducible nitric oxide synthase (iNOS) is induced to generate the important mediator nitric oxide (NO). Interleukin 1β (IL-1β) induces iNOS messenger RNA (mRNA), iNOS protein, and NO in rat hepatocytes. We found that the stability of iNOS mRNA changed during the induction and that the antisense (AS) strand corresponding to the 3′-untranslated region (3′UTR) of iNOS mRNA was transcribed from the

iNOS

gene. Expression levels of the iNOS AS transcript correlated with those of iNOS mRNA. The 1.5-kilobase region 3′-flanking to

iNOS

gene exon 27 was involved in IL-1β induction. Knockdown experiments suggest that sense oligonucleotides to iNOS mRNA significantly reduced iNOS mRNA levels in the hepatocytes by blocking the interaction between iNOS mRNA and the AS transcript. Overexpression of iNOS AS transcript stabilized the reporter luciferase mRNA through the fused iNOS mRNA 3′UTR. These results together with the data in a yeast RNA-hybrid assay suggested that the iNOS AS transcript interacted with iNOS mRNA and stabilized iNOS mRNA. The iNOS mRNA colocalized with the AU-rich element-binding protein HuR, a human homolog of embryonic lethal-abnormal visual protein, and heterogeneous nuclear ribonucleoprotein L (hnRNP L) in the cytoplasm of rat hepatocytes. Interaction assays further revealed that the iNOS AS transcript interacted with HuR, which interacted with hnRNP L, suggesting that iNOS mRNA, the AS transcript, and the RNA-binding proteins may mutually interact.

Conclusion:

The natural AS transcript of the

iNOS

gene interacts with iNOS mRNA and may play an important role in the stability of iNOS mRNA. This RNA-RNA interaction may be a new therapeutic target for NO-mediating inflammatory diseases. (Hepatology 2008.)
Aberrant methylation of multiple tumor suppressor genes in aging liver, chronic hepatitis, and hepatocellular carcinoma
Authors: Nishida Naoshi , Nagasaka Takeshi , Nishimura Takafumi , Ikai Iwao , Boland Richard C. , Goel Ajay
Published: December 2007

Aberrant DNA methylation is an important epigenetic alteration in hepatocellular carcinoma (HCC). However, the molecular processes underlying the methylator phenotype and the contribution of hepatitis viruses are poorly understood. The current study is a comprehensive methylation analysis of human liver tissue specimens. A total of 176 liver tissues, including 77 pairs of HCCs and matching noncancerous liver and 22 normal livers, were analyzed for methylation. Methylation of 19 epigenetic markers was quantified, and the results were correlated with different disease states and the presence or absence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. Based on methylation profiles, the 19 loci were categorized into 3 groups. Normal liver tissues showed methylation primarily in group 1 loci (

HIC
-
1

,

CASP8

,

GSTP1

,

SOCS1

,

RASSF1A

,

p16

,

APC

), which was significantly higher than group 2 (

CDH1

,

RUNX3

,

RIZ1

,

SFRP2

,

MINT31

) and group 3 markers (

COX2

,

MINT1

,

CACNA1G

,

RASSF2

,

MINT2

,

Reprimo

,

DCC

) (

P

< 0.0001). Noncancerous livers demonstrated increased methylation in both group 1 and group 2 loci. Methylation was significantly more abundant in HCV-positive livers compared with normal liver tissues. Conversely, HCC showed frequent methylation at each locus investigated in all 3 groups. However, the group 3 loci showed more dense and frequent methylation in HCV-positive cancers compared with both HBV-positive cancers and virus-negative cancers (

P

< 0.0001).

Conclusion:

Methylation in HCC is frequent but occurs in a gene-specific and disease-specific manner. Methylation profiling allowed us to determine that aberrant methylation is commonly present in normal aging livers, and sequentially progresses with advancing stages of chronic viral infection. Finally, our data provide evidence that HCV infection may accelerate the methylation process and suggests a continuum of increasing methylation with persistent viral infection and carcinogenesis in the liver.
Christian religious functioning and trauma outcomes
Authors: Harris J. Irene , Erbes Christopher R. , Engdahl Brian E. , Olson Raymond H. A. , Winskowski Ann Marie , McMahill Joelle
Published: December 2007

While some trauma survivors find their faith helpful in recovery, others find it a source of distress, and still others abandon their faith. More complex conceptualizations of religious functioning are needed to explore its relationship with trauma. This study explores such relationships using measures of religious action and behaviors in a community sample of 327 church‐going, self‐identified trauma survivors. A principal components analysis of positive and negative religious coping, religious comforts and strains, and prayer functions identified two dimensions: Seeking Spiritual Support, which was positively related to posttraumatic growth, and Religious Strain, which was positively related to posttraumatic symptoms. © 2007 Wiley Periodicals, Inc. J Clin Psychol 64: 17–29, 2008.
Cognitive mediational deficits and the role of coping styles in pedophile and ephebophile Roman Catholic clergy
Authors: Ryan Gregory P. , Baerwald Jeffrey P. , McGlone Gerard
Published: December 2007

This study was designed to examine hypothesized differences between sex offending and nonoffending Roman Catholic clergy on cognitive mediation abilities as measured by the Rorschach Inkblot Test (H. Rorschach, 1921/1942). This study compared 78 priest pedophiles and 77 priest ephebophiles with 80 nonoffending priest controls on the Inkblot test using J. E. Exner's (2003) Comprehensive System. The three groups were compared on seven variables that constitute Exner's Cognitive Mediation cluster. Additionally, the groups' coping styles were compared to examine the interaction of coping style and cognitive mediational abilities. We found interactions between coping style and offending status across most of the cognitive variables indicating impairment in the mild to pathological ranges. Moreover, significantly higher unusual thinking styles (Xu%) and significantly lower conventional thinking styles (X+%) in offenders compared to nonoffenders. Those with an Extratensive style (n=31) showed significantly higher distorted thinking when compared to the Introversive (n=81), Ambitent (n=73), and Avoidant (n=50) coping styles. This study suggests that offenders display significantly higher distorted thinking styles than do nonoffenders. Possible reasons for these discrepancies and the role of coping styles in abusive behaviors were discussed. © 2007 Wiley Periodicals, Inc. J Clin Psychol 64: 1–16, 2008.
Self‐determination theory, motivational interviewing, and the treatment of clients with acute suicidal ideation
Authors: Britton Peter C. , Williams Geoffrey C. , Conner Kenneth R.
Published: December 2007

An overwhelming number of individuals who die by suicide suffer from mental disorders, but comparatively few are seen in psychological or psychiatric treatment. Given the efficacy of psychosocial interventions in decreasing suicide‐related behavior, the development of strategies to increase motivation for treatment is critical for clients with acute suicidal ideation. Self‐Determination Theory (SDT) provides a framework for understanding how the therapeutic relationship can affect clients' motivation for treatment. When working with clients with serious suicidal ideation, clinicians can use the principles of SDT or interventions that are congruent with SDT, such as motivational interviewing (MI), to increase clients' engagement in treatment and improve treatment outcome. SDT‐based suggestions and an adaptation of MI are introduced to guide clinicians through this process. © 2007 Wiley Periodicals, Inc. J Clin Psychol 64: 52–66, 2008
Psychometric properties of the Beck Depression Inventory‐II in nonclinical adolescent samples
Authors: Osman Augustine , Barrios Francisco X. , Gutierrez Peter M. , Williams John E. , Bailey Jennifer
Published: December 2007

This study examined the factor structure and psychometric properties of the Beck Depression Inventory‐II (BDI‐II; A. T. Beck, Steer, & Brown, 1996) in samples of high‐school adolescents (N=414; 210 boys and 204 girls, ages 14–18 years). Confirmatory factor analyses provided satisfactory fit estimates for the two‐ and three‐factor oblique solutions reported frequently in the extant literature. The solution to a general factor with domain‐specific somatic and cognitive‐affective factors was examined as an alternative model to previously established models for the current high‐school sample data. Results provided stronger support for the general factor model. Estimates of internal consistency for scores on this instrument were high (coefficient α=.92, average interitem correlation=.35). The mean BDI‐II total score for the nonclinical samples (M=12.50, SD=10.50) was compared with the mean scores reported for various adolescent normative samples in the extant literature. The BDI‐II total score correlated moderately and significantly with scores on self‐report measures of hopelessness (r=.63), anxiety (r=.53), and suicide‐related behaviors (r=.57), providing support of adequate correlates for the BDI‐II. Estimates of known‐groups validity were evaluated using data from a small sample of 167 clinical adolescent inpatients. Specific study findings, limitations, and recommendations are discussed. © 2007 Wiley Periodicals, Inc. J Clin Psychol 64: 83–102, 2008.
The relational context of aggression in borderline personality disorder: using adult attachment style to predict forms of hostility
Authors: Critchfield Kenneth L. , Levy Kenneth N. , Clarkin John F. , Kernberg Otto F.
Published: December 2007

Attachment theory provides a framework for understanding and predicting critical aspects of aggression in the personality disorders. An association between borderline personality disorder (BPD) and insecure forms of adult attachment marked by high relationship anxiety has been repeatedly observed in the empirical literature. Aggression also has been linked to insecure attachment. The present study extends previous work by exploring the degree to which the underlying attachment dimensions of relationship anxiety and avoidance are associated in BPD with the following forms of hostility: (a) direct aggression (verbal or physical) initiated towards others, (b) expectation/perception of aggression from others (including “reactive” counteraggression when/if provoked), (c) aggression directed towards the self in the form of suicidality or parasuicidality, and (d) affective experience of irritability or anger. The issue was studied in a sample of 92 patients diagnosed with BPD. Results show significant association between more fearful forms of attachment (simultaneous presence of relationship anxiety and avoidance) and the more reactive form of aggression involving expectation of hostility from others. Self‐harm was significantly associated only with relational avoidance while anger and irritability were associated only with relational anxiety. Implications for understanding relational aspects of BPD aggression in research and clinical work are discussed. © 2007 Wiley Periodicals, Inc., J Clin Psychol 64: 67–82, 2008.
Health care disparities and language use at home among latino, asian american, and american indian adolescents: Findings from the california health interview survey
Authors: Hahm Hyeouk Chris , Lahiff Maureen , Barreto Rose M. , Shin Sunny , Chen Wan‐Yi
Published: December 2007

Using the 2001 California Health Interview Survey, this study compared health status, medical insurance, and having a usual source of care for 2,230 ethnic minority adolescents based on language use at home: Group 1, English only; Group 2, both English and another language; and Group 3, exclusively another language. Adjusting for demographic variables, adolescents in Group 3 were more likely to report fair or poor health (OR=2.37, p=.012) and to not have medical insurance (OR=4.61, p<.001) compared to adolescents in Group 1. Young adolescents in Group 3 were more likely to have no usual source of care (OR=4.07, p=.029). Interventions need to consider language barriers in the context of an adolescent's age. © 2007 Wiley Periodicals, Inc.
Faith‐placed parenting intervention
Authors: Patrick Megan E. , Rhoades Brittany L. , Small Meg , Coatsworth J. Douglas
Published: December 2007

Collaboration with religious institutions is recommended as a frontier for prevention science. Little is known about the effectiveness of programs currently disseminated by churches. This pilot program investigated potential advantages and disadvantages of university collaborations in faith settings, by implementing the Staying Connected with Your Teen parenting program (N=13 parents) in a single congregation. The mixed‐method assessment included surveys, a focus group, and observation to gather information about implementation. Meeting time, location, parallel youth programming, endorsement by trusted leaders, and use of existing social networks were indicated by past research and described by participants as potential advantages to an evidence‐based program implementation in faith communities. © 2007 Wiley Periodicals, inc.
Violence breeds violence: Childhood exposure and adolescent conduct problems
Authors: Weaver Chelsea M. , Borkowski John G. , Whitman Thomas L.
Published: December 2007

The relationships between childhood exposure to violence and adolescent conduct problems were investigated in a sample of 88 primiparous adolescent mothers and their children. Regression analyses revealed that witnessing violence and victimization prior to age 10 predicted delinquency and violent behaviors, even after controlling for prenatal maternal and early childhood externalizing problems. Social competency and depression during middle childhood moderated the relationship between victimization and violent behaviors for girls, but not boys: Lower levels of social competency and depression served as risk factors for delinquency among teenage girls who experienced victimization during childhood. These findings have important implications for youth violence prevention programs. © 2007 Wiley Periodicals, Inc.
Thickness‐two graphs part one: New nine‐critical graphs, permuted layer graphs, and Catlin's graphs
Authors: Boutin Debra L. , Gethner Ellen , Sulanke Thom
Published: December 2007

The purpose of this article is to offer new insight and tools toward the pursuit of the largest chromatic number in the class of thicknesstwo graphs. At present, the highest chromatic number known for a thickness‐two graph is 9, and there is only one known color‐critical such graph. We introduce 40 small 9‐critical thickness‐two graphs, and then use a newconstruction, the permuted layer graphs, together with a construction of Hajós to create an infinite family of 9‐critical thickness‐two graphs. Finally, a non‐trivial infinite subfamily of Catlin's graphs, with directly computable chromatic numbers, is shown to have thickness two. © 2007 Wiley Periodicals, Inc. J Graph Theory 57: 198–214, 2008
Infinite paths in planar graphs V, 3‐indivisible graphs
Authors: Yu Xingxing
Published: December 2007

We prove Nash‐Williams' conjecture that every 4‐connected, 3‐indivisible, infinite, planar graph contains a spanning 2‐way infinite path. A graph is said to be 3‐indivisible if the deletion of any finite set of vertices results in at most two infinite components. © 2007 Wiley Periodicals, Inc. J Graph Theory 57: 275–312, 2008
On the maximum number of cycles in a planar graph
Authors: Aldred R. E. L. , Thomassen Carsten
Published: December 2007

Let G be a graph on p vertices with q edges and let r = q − p = 1. We show that G has at most ${15\over 16} 2^{r}$ cycles. We also show that if G is planar, then G has at most 2r − 1 = o(2r − 1) cycles. The planar result is best possible in the sense that any prism, that is, the Cartesian product of a cycle and a path with one edge, has more than 2r − 1 cycles. © Wiley Periodicals, Inc. J. Graph Theory 57: 255–264, 2008
Practice and endpoint accuracy with the left and right hands of old adults: The right‐hemisphere aging model
Authors: Poston Brach , Enoka Joel A. , Enoka Roger M.
Published: December 2007

The purpose of the study was to quantify the aging‐related differences in endpoint accuracy during isometric contractions of the left and right hands based on the prediction that declines in motor performance with aging may be greater for muscles controlled by the right hemisphere. Twelve young (6 men, 25 ± 5 years) and 12 old (6 men, 76 ± 6 years) adults performed a task that involved matching the peak of a force–time trajectory to a target. The old adults were less accurate than the young men and exhibited greater endpoint error with the left hand than the right hand on day 1, but not on days 2 and 3. Although electromyographic amplitude was similar between hands, old adults exhibited greater timing variability. These findings indicate that given sufficient practice there was no difference in endpoint accuracy between the left and right hands of old adults, which is not consistent with the prediction of an asymmetrical decline in motor performance by the right‐hemisphere aging model. Conversely, an inability by an old adult to achieve similar accuracy with both hands during such tasks likely indicates an underlying motor impairment. Muscle Nerve, 2007
Trialkoxysilane‐capped acrylic resin/alumina hybrid materials prepared by in situ sol–gel process
Authors: Li Mingqi , Zhou Shuxue , You Bo , Wu Limin
Published: December 2007

The (3‐methacryloxypropyl)trimethoxysilane (MPMS) capped acrylic resin/alumina hybrid materials with highly homogeneous structure were successfully prepared by in situ sol–gel process. The effects of the contents of alumina, ethylacetoacetate (EAA), and water as well as the types of catalyst on the structures and properties of the hybrid materials were studied. It was found that the Tg, thermal stability, microhardness, and Young's modulus of the hybrid materials were obviously improved with increasing alumina and water contents, low EAA content, and catalyst employed. POLYM. COMPOS., 2008. © 2007 Society of Plastics Engineers
Synthesis and characterization of organo‐attapulgite/polyaniline‐dodecylbenzenesulfonic acid based on emulsion polymerization method
Authors: Lei Xiping , Liu Yushan , Su Zhixing
Published: December 2007

Organo‐attapulgite (OAT) was obtained by pretreating attapulgite (AT) with hexadecyltrimethyl ammonium bromide (HDTMABr) and dodecylbenzenesulfonic acid doped polyaniline (PAn‐DBSA) (OAT/PAn‐DBSA) was synthesized by emulsion polymerization at different OAT weight ratios. The perhaps polymerization procedure was supposed. The chemical structure and electronic absorption of the composites was confirmed by FTIR and UV–Vis spectroscopy, respectively. According to the X‐ray diffraction (XRD) results, it can be concluded that HDTMABr and PAn‐DBSA was just adsorbed on the surface of AT during the cation‐exchange process and OAT respectively without destroying the crystalline structure of AT or OAT. The composites showed a higher thermal stability than pure PAn‐DBSA by introduction of OAT into this polymerization system by using TGA analysis. Morphologies of the samples were confirmed by TEM and it showed that OAT was dispersed well in organic solvent after AT was pretreated with HDTMABr. The morphologies of OAT/PAn‐DBSA also supported the perhaps formation procedure we hypothesized. The electrical conductivity of the composite decreased with increasing the feed weight ratios of OAT in this polymerization system. POLYM. COMPOS., 2008 © 2007 Society of Plastics Engineers
Impact modified polyamide‐6/organoclay nanocomposites: Processing and characterization
Authors: Isik Isil , Yilmazer Ulku , Bayram Goknur
Published: December 2007

The effects of melt state compounding of ethylene‐butyl acrylate‐maleic anhydride (E‐BA‐MAH) terpolymer and/or three types of organoclays (Cloisite® 15A, 25A, and 30B) on thermal and mechanical properties and morphology of polyamide‐6 are investigated. E‐BA‐MAH formed spherical domains in the materials to which it is added, and increased the impact strength, whereas the organoclays decreased the impact strength. In general, the organoclays increased the tensile strength (except for Cloisite 15A), Young's modulus and elongation at break, but the addition of E‐BA‐MAH had the opposite effect. XRD patterns showed that the interlayer spacing for the organoclays Cloisite 25A and Cloisite 30B increased in both polyamide‐6/organoclay binary nanocomposites and in polyamide‐6/organoclay/impact modifier ternary systems. TEM analysis showed that exfoliated‐intercalated nanocomposites were formed. The crystallinities of polyamide‐6/organoclay nanocomposites were in general lower than that of polyamide‐6 (except for Cloisite 15A). In ternary nanocomposites, crystallinities generally were lower than those of polyamide‐6/organoclay nanocomposites. Cloisite 15A containing ternary nanocomposites had higher tensile and impact strengths and Young's modulus than the ternary nanocomposites prepared with Cloisite 25A and Cloisite 30B, owing to its surface hydrophobicity and compatibility with the impact modifier. POLYM. COMPOS., 2008. © 2007 Society of Plastics Engineers
Polyester composites reinforced with noncrimp stitched glass fabrics: Experimental characterization of composites and investigation on the interaction between glass fiber and polyester matrix
Authors: Cecen Volkan , Sarikanat Mehmet , Seki Yoldas , Yildiz Hasan , Tavman Ismail H.
Published: December 2007

The primary purpose of the study was to investigate the anisotropic behavior of different noncrimp stitched fabric reinforced polyester composites. The effects of geometric variables on composite structural integrity and strength are illustrated. Hence, tensile, three‐point bending flexural and short beam shear tests were conducted up to failure on specimens strengthened with different layouts of fibrous plies in noncrimp stitched fabric. The remark, based on the observations while tensile testing, is that the stress–strain curves of polyester based composites were linear in the direction of fibers. However, in the matrix dominated orientations nonlinear relation between the stress and the strain was observed. Another aim of the present work was to investigate the interaction between glass fiber and polyester matrix. The experiments, in conjunction with scanning electron photomicrographs of fractured surfaces of composites, were interpreted in an attempt to explain the interaction between glass fiber and polyester and were interpreted in an attempt to explain the instability of polyester resin–glass fiber interfaces. It was concluded that the polymer was either deposited between adjacent fibers or as widely separated islands on the fiber surface. Infrared spectra of the cured polyester and its glass fiber composite were obtained by Fourier transform infrared spectroscopy. POLYM. COMPOS., 2008. © 2007 Society of Plastics Engineers
Processability studies of silica‐thermoset polymer matrix nanocomposites
Authors: Lekakou C. , Kontodimopoulos I. , Murugesh A.K. , Chen Y.L. , Jesson D.A. , Watts J.F. , Smith P.A.
Published: December 2007

The aim of this study is to investigate the processability of silica‐thermoset polymer matrix nanocomposites in terms of dispersion of silica nanoparticles and their effect on curing. Two thermosetting resins were considered, an epoxy and a polyester resin, with 5% silica, although 1% silica was also used in preliminary studies in the polyester system. Various combinations of mechanical mixing and sonication were investigated for the dispersion of silica nanoparticles under different processing conditions and times in solvent‐free and solvent‐containing systems. It was found that the best dispersion route involved a solvent‐aided dispersion technique. Consequently, different procedures for the solvent removal were investigated. Optical microscopy and SEM were used to characterize the resulting nanocomposites. DSC and rheological DMTA tests demonstrated that the silica nanoparticles shorten the gel time and promote curing in these thermosetting systems. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
Elongational viscosity of LDPEs and polystyrenes using entrance loss data
Authors: Walczak K. , Gupta M. , Koppi K.A. , Dooley J. , Spalding M.A.
Published: December 2007

For two low‐density polyethylenes and two polystyrenes, axisymmetric and planar elongational viscosities are estimated using entrance loss data from capillary and slit rheometers, respectively. The elongational viscosity is estimated by optimizing the values of various parameters in the Sarkar–Gupta elongational viscosity model such that the entrance loss predicted by a finite element simulation agrees with the corresponding experimental data. The predicted entrance loss is in good agreement with the experimental data at high flow rates. The difference in the experimental and predicted entrance loss at lower flow rates might have been caused by large error in the experimental data in this range. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
Structural characterization and mass transfer properties of dense segmented polyurethane membrane: Influence of hard segment and soft segment crystal melting temperature
Authors: Mondal S. , Hu J.L.
Published: December 2007

An attempt has been taken to investigate the microstructure and mass transfer properties of polycaprolactone diol (Mn = 2000 g mol–1, PCL 2000)‐based dense segmented polyurethane (SPU) membrane as a function of hard segment (HS) content. Structure of SPUs were investigated by Fourier transform infrared analysis, wide angle X‐ray diffraction, differential scanning calorimetry, dynamic mechanical thermal analysis, and scanning electron microscopy (SEM). On the other hand, mass transfer properties were measured by equilibrium sorption, dynamic sorption, and water vapor permeability measurements. From the experimental results, it was observed that with the increasing HS content in SPU the percentage crystallinity decreases, whereas the glassy state storage modulus increases. α transition temperature of polyurethane copolymers also increases with increasing HS content. SEM micrograph shows the dense surface structure of SPU films. Mass transfer rate of dense polyurethane membranes decreases with increasing HS content. In contrast, hydrophilic segment and soft segment crystal melting could enhance the mass transfer properties. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
Interaction of thermoplastic polyurethane with polyamide 1212 and its influence on the thermal and mechanical properties of TPU/PA1212 blends
Authors: Li Wanli , Liu Jinli , Hao Chaowei , Jiang Kai , Xu Duanfu , Wang Dujin
Published: December 2007

To improve the heat resistance of polyester‐based thermoplastic polyurethane (TPU), in the present work, polyamide 1212 (PA1212) was chosen as a modifier and a series of TPU/PA1212 blends with different compositions were prepared using a twin screw extruder. The solubility parameters, characteristic of chemical structures, hydrogen‐bonding interaction, as well as interfacial tension of the single component and blends were taken into account to describe the good compatibility of TPU/PA1212 blends. The effect of PA1212 content on the rheological behaviors, morphology, mechanical, and thermal properties of TPU/PA1212 blends were systematically investigated with scanning electron microscope, tensile strength measurement, thermal gravimetry analysis, differential scanning calorimetry, and Vicat softening temperature (VST). The results showed that PA1212 formed submicron dispersion domains in the TPU matrix, indicating good compatibility between TPU and PA1212. A slight increase of the tensile strength was achieved as PA1212 content is relatively low. Because of the strong hydrogen‐bonding interaction between TPU and PA1212, the thermal stability of the blends is improved, and VST values rise up from about 80 (pure TPU) to 100°C, showing attractive potential application. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
Macroscopic failure of multilayered viscoelastic polymers
Authors: Wu Chunhui , Mantell Susan C. , Davidson Jane H.
Published: December 2007

This study considers creep deformation (macroscopic failure) of laminated polymer materials. A closed form analytical model is developed to characterize creep in laminates loaded in the linear viscoelastic region. For nonlinear viscoelastic loading, a numerical solution is developed. The models are based on an application of laminated plate theory to materials with viscoelastic layers. Both approaches are able to predict laminate behavior with input of appropriate material properties for each layer. Experimental data are presented, which confirm the validity of the analytical model for laminates constructed from nylon66 and liquid crystalline polymer films. The validated macroscale failure models are capable of characterizing a variety of materials. A case study is included to demonstrate the influence of layer properties and orientation on overall laminate performance. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
A study of nano‐mechanical and macro‐mechanical properties of ethylene vinyl acetate
Authors: Kim Jaehyun , Wang Janson , Kang Ho‐Jong , Talke Frank
Published: December 2007

Nano‐ and macro‐mechanical properties of ethylene vinyl acetate (EVA) with various amounts of vinyl acetate (VA) have been investigated. Nano‐mechanical properties (modulus and hardness) were obtained using nano‐indentation measurements while macro‐mechanical properties were determined using tensile test measurements. A decrease in Young's modulus and hardness was observed with increasing VA content for both nano‐ and macro‐mechanical measurements. An increase in Young's modulus and hardness was observed as a function of the draw ratio keeping the VA content constant. The difference between macro‐ and nano‐mechanical properties as a function of VA content and draw ratio is explained in terms of crystallinity and chain orientation. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers
Establishment and growth pattern ofPinus pumilaunder a forest canopy in central Kamchatka
Authors: Okuda Masaki , Sumida Akihiro , Ishii Hiroaki , Vetrova Valentina P. , Hara Toshihiko
Published: December 2007

We investigated the spatial distribution and growth of the Siberian dwarf pine (Pinus pumila) in a valley–foothill larch–birch (Larix cajanderi–Betula platyphyllaas canopy trees) mixed forest of fire origin located in central Kamchatka with the aim of elucidating the ecological features ofP. pumilawhen it is an undergrowth species in a forest. The spatial distribution of all individuals of all tree species was clumped, and the spatial distribution of the two canopy tree species did not repulsively affect that ofP. pumila(i.e., its establishment site). These results suggest that the regeneration ofP. pumiladoes not depend on canopy gaps. However, the analysis using a growth model indicated that the canopy trees negatively affected the growth ofP. pumilaand that the negative effect ofL. cajanderionP. pumilagrowth was stronger than that ofB. platyphylla. The direction of the crown extension ofP. pumilawas weakly related to the open‐space direction. Our results suggest that, although the spatial pattern of establishment ofP. pumilais not repulsed by the distribution of canopy trees, the crown can spread horizontally toward the more sparsely populated areas of the canopy trees where they may have higher growth rates.
Exploring dual identification among Muslim‐American emerging adults: A mixed methods study
Authors: Sirin Selcuk R. , Bikmen Nida , Mir Madeeha , Fine Michelle , Zaal Mayida , Katsiaficas Dalal
Published: December 2007

This mixed methods study explored dual identification among Muslim‐American emerging adults of immigrant origin. A closer look was taken at the relationship between American and Muslim identifications and how this relationship was influenced by experiences of discrimination, acculturative and religious practices, and whether it varied by gender. Data were gathered from 97 Muslim Americans (ages 18–25) who completed a survey and produced identity maps, a pictorial representation of hyphenated identities. The findings showed that young people found a way of allowing their Muslim and American identities to co‐exist, and only a small minority of the participants seemed to experience identity conflict. While religiosity was the only predictor of Muslim identification, young peoples’ identification with mainstream United States culture was predicted by discrimination‐related stress and acculturative practices. Gender moderated the relationship between Muslim and American identities in both survey measures and identity maps.
Long‐term survival in patients older than 80 years hospitalised for heart failure. A 5‐year prospective study
Authors: Mahjoub Haïfa , Rusinaru Dan , Soulière Vicky , Durier Chloé , Peltier Marcel , Tribouilloy Christophe
Published: December 2007

Background:

Although heart failure (HF) is frequent in elderly patients, few studies have focused on patients older than 80 years.

Aims:

To evaluate the clinical features, treatment and long‐term prognosis of HF in patients older than 80 years.

Methods and results:

Consecutive patients hospitalised for a first HF episode in the Somme Department (France) during 2000 were prospectively included. Of the 799 included patients, 305 (38%) were aged over 80 years. The elderly patients were mostly women with a high prevalence of atrial fibrillation, ischaemic and hypertensive heart disease. Ejection fraction (EF) was assessed in 68.5% of elderly patients and 61% had EF ≥50%. Angiotensin‐converting enzyme inhibitors, beta‐blockers, oral anticoagulants and statins were prescribed less frequently in elderly patients. The 5‐year survival in elderly patients was 19%, dramatically lower than the survival of age‐ and sex‐matched general population (48%). Cardiovascular causes were recorded in over 60% of deaths. On multivariable analysis, cancer, renal insufficiency, old myocardial infarction, diabetes, hyponatraemia and age were predictors of mortality in elderly patients. Reduced EF was a potent predictor of death (HR 1.72, 95%CI 1.24–2.37, p=0.001) in elderly patients.

Conclusion:

Long‐term prognosis in HF patients older than 80 years is poor, with a dramatic excess mortality compared to the elderly general population. Life‐saving drugs are largely underused in elderly HF patients.
Preservation of heart function in diabetic rats by the combined effects of muscle cell implantation and insulin therapy
Authors: Kim Byung‐Ok , Verma Subodh , Weisel Richard D. , Fazel Shafie , Jia Zhi‐Qiang , Mizuno Tomohiro , Li Ren‐Ke
Published: December 2007

Background:

Diabetic cardiomyopathy is a common cause of heart failure in diabetic patients, but current treatments do not directly improve ventricular function. Cell transplantation can prevent cardiac dilatation after injury, and may also prevent congestive heart failure in diabetic cardiomyopathy.

Aim:

This study evaluated the functional effects of smooth muscle cells (SMCs) implanted into the myocardium of insulin‐ and non insulin‐treated diabetic rats.

Methods:

Four weeks after streptozotocin infusion, adult Wistar rats were implanted with BrdU‐labelled SMCs or culture media (N=12/group). Six rats in each group were also treated with insulin. Echocardiograms were performed at 0, 4 and 8 weeks after streptozotocin injection, and histology and heart function were evaluated at 4 weeks after implantation.

Results:

Blood glucose levels decreased after insulin treatment. Among cell‐injected rats, histology indicated that those that did not receive insulin retained fewer surviving BrdU+ SMCs, and a smaller volume of myocardial tissue positive for αsmooth muscle actin. Cardiac function was preserved in the insulin‐treated groups relative to those that did not receive insulin. Among insulin‐treated rats, the cell‐injected group functioned better than the media‐injected group.

Conclusions:

Diabetic cardiomyopathy is partially treatable with insulin; however, a combination of SMC transplantation and insulin treatment produced the best functional result. Cell transplantation may prevent the progression of diabetic cardiomyopathy in patients whose glucose levels are controlled with insulin.
A comparison of the relationship between depression, perceived disability, and physical performance in persons with chronic pain
Authors: Alschuler Kevin N. , Theisen‐Goodvich Mary E. , Haig Andrew J. , Geisser Michael E.
Published: December 2007

This study examined the relationships between self‐report of depressive symptoms, perceived disability, and physical performance among 267 persons with chronic pain. Prior research has reported a relationship between depression and disability using self‐report measures. However, self‐report instruments may be prone to biases associated with depression as depressed persons with pain may have an exaggerated negative view of their level of function. In addition, we examined whether the relationship between depression and functional activity was mediated by physiologic effort (as measured by heart rate). The results indicated that self‐report of depressive symptoms (using the Center for Epidemiological Studies‐Depression Scale (CES‐D)) was significantly correlated with self‐report of disability on the Quebec Back Pain Disability Scale (QBPDS) and physical performance on the Progressive Isoinertial Lifting Evaluation (PILE). Regression analyses revealed that depression assessed by the CES‐D significantly contributed to the prediction of QBPDS scores and PILE performance even when controlling for age, gender, site of pain, and pain intensity. The magnitude of the relationships between depression and self‐report and functional activity were similar, suggesting that a self‐report bias associated with depression is not responsible for an observed relationship between depression and disability. Physiologic effort partially mediated the relationship between depression and physical performance. The findings further highlight the importance of depression in the experience of chronic pain.
Cognitive appraisal and coping in chronic pain patients
Authors: Ramírez‐Maestre Carmen , Esteve Rosa , López Alicia E.
Published: December 2007

Objectives: This study analyses the relationships between patients’ cognitive appraisals concerning their pain and the coping strategies they use. In addition, the way the coping strategy influences the intensity of perceived pain and impairment in these patients was studied.

Methods: One hundred and twenty two patients with musculoskeletal chronic pain participated. The assessment tools were as follows: The Cognitive Appraisal Inventory for Chronic Pain Patients (CAI), the Vanderbilt Pain Management Inventory (VPMI), the McGill Pain Questionnaire (MPQ) and the Impairment and Functioning Inventory for Chronic Pain Patients (IFI). The hypothetical model was empirically tested using the LISREL 8.20 software package and the unweighted least squares method.

Results: High levels of challenge appraisal were associated with low levels of passive coping and high levels of active coping strategies, whereas the harm, loss or threat appraisal predicted high use of passive coping strategies. Passive coping had three statistically significant path coefficients: high levels of passive coping were associated with low levels of functioning and high levels of pain intensity and impairment. However, high levels of active coping reported high levels of daily functioning.

Discussion: By analysing the cognitive appraisals made by chronic pain patients, clinicians could make better predictions regarding the way they cope and adjust.
Smoking in relation to anxiety and depression: Evidence from a large population survey: The HUNT study
Authors: Mykletun Arnstein , Overland Simon , Aarø Leif Edvard , Liabø Hanne-Marthe , Stewart Robert
Published: December 2007

Smoking is reported to be associated with depression and anxiety. The present study (a) examines these associations taking comorbidity into account, (b) investigates possible confounders, (c) examines how former smokers compared to current and never-smokers in terms of anxiety and depression, and if anxiety and depression decline by time since cessation. Participants (66%) aged 20–89 years in a population-based health survey (N = 60,814) were screened employing the HADS. (a) The association with smoking was strongest in comorbid anxiety depression, followed by anxiety, and only marginal in depression. Associations were stronger in females and younger participants. (b) Variables partly accounting for the association comprised somatic symptoms, socio-demographics, alcohol problems, and low physical activity. (c) Anxiety and depression were most common in current smokers, followed by quitters, and then never-smokers. No decline in anxiety or depression was found with time since cessation. Previous studies of associations between depression and smoking might have overestimated the association when ignoring comorbid anxiety.
Awareness of Metabolic Concerns in Patients With Bipolar Disorder: A Survey of European Psychiatrists
Authors: Bauer Michael , Lecrubier Yves , Suppes Trisha
Published: December 2007

Purpose.

An online survey of European psychiatrists assessed awareness of the metabolic syndrome and its influence on the management of bipolar disorder.

Materials and methods.

Psychiatrists in the United Kingdom, France, Germany, Spain, and Italy were surveyed from April to June 2006. Eligibility criteria w ere 4–30 years in practice, ≥50% of time in direct patient care, had seen ≥10 bipolar patients in the preceding month. Aggregate data were weighted to represent the practicing physician population per country.

Results.

of 718 respondents, 56% had diagnosed metabolic syndrome. Respondents reported that metabolic syndrome prevalence was higher in bipolar patients (25%) than in the general population (20%). Seventy-two percent felt that metabolic syndrome poses significant health risks, warranting monitoring/treatment, and were most concerned with the bipolar medication adverse effects of weight gain, cognitive impairment, and glucose intolerance. Survey respondents recognized clear differences among psychotropic agents in the propensity to induce metabolic adverse effects. Sixty-five percent of respondents indicated that they had made interviewing and monitoring changes in the past three years as a result of metabolic concerns.

Conclusions.

European psychiatrists view metabolic syndrome as highly prevalent in the general population and in bipolar patients; twothirds have changed their management of bipolar patients because of metabolic health concerns.