bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of composition and component structure on thermal behavior and miscibility of polypropylene catalloys
Authors: Shangguan Yonggang , Tao Liyang , Zheng Qiang 
Published: June 2007

AbstractThe thermal behavior and the miscibility of an in‐situ polypropylene blend named polypropylene catalloys (PP‐cats) were investigated by using modulated differential scanning calorimeter (MDSC). It is found that all PP‐cats samples present two glass transitions, one of which is ascribed to the ethylene‐propylene random copolymer (EPR), and the other, to isotactic polypropylene (PP). However, no glass transition of ethylene‐propylene block copolymer (E‐b‐P) responsible for a third component in PP‐cats could be found. With the increase of EPR, the glass transition temperatures responding to PP and EPR components, Tg, PP and Tg, EPR, shift to low temperature, because of the enhancement of the interaction between PP and EPR component and the increase of ethylene content in EPR, respectively. Furthermore, the difference between Tg, PP and Tg, EPR remarkably decreases with the increase of the total ethylene content in PP‐cats, which indicates that the miscibility of PP‐cats is strongly dependent on the composition. Comparing the Tg, PP and Tg, EPR with Tg of fractionated PP and EPR, we ascribe the Tg change of PP fraction to the increase of EPR content; while that of EPR, to the increase of ethylene content in EPR. These experimental results suggest that the existence of E‐b‐P plays an important role in improving the miscibility between propylene homopolymer and EPR in PP‐cats. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Preparation and evaluation of a vancomycin‐immobilized silica monolith as chiral stationary phase for CEC
Authors: Dong Xiaoli , Dong Jing , Ou Junjie , Zhu Yan , Zou Hanfa 
Published: June 2007

AbstractEnantiomeric separations in CEC with the macrocyclic antibiotic vancomycin immobilized silica monolith as a chiral stationary phase are presented. The monolithic silica capillary columns were prepared by a sol–gel process in fused‐silica capillaries with an inner diameter of 50 μm and subsequently in situ immobilization of vancomycin as a chiral selector by reductive amination. Enantioselectivity was obtained for eight pairs of enantiomers in nonaqueous polar organic or aqueous mobile phases and most of them were baseline‐separated with high column efficiencies. It was observed that the organic modifier ratio (MeOH/ACN) in the polar organic mobile phase played a significant role in controlling the resolution and efficiency of the enantiomers. In enantiomeric separation of propranolol, repeatability for column efficiency and resolution in the nonaqueous mobile phase was given in terms of RSD values at 1.1 and 2.3% (n = 5) for run‐to‐run injections and 7.2 and 9.6% (n = 5) for column‐to‐column testing while repeatability for the separation of thalidomide in the aqueous mobile phase was given in terms of RSD values at 1.5, 2.8% and 6.1, 10.5%, respectively.
Enantioseparation of chiral tropa alkaloids by means of cyclodextrin‐modified microemulsion electrokinetic chromatography
Authors: Bitar Yaser , Holzgrabe Ulrike 
Published: June 2007

AbstractCD‐modified microemulsion EKC as a CE technique has been applied to the chiral separation of atropine, scopolamine, ipratropium and homatropine. Enantioseparations of these tropa alkaloids were optimized by using a standard oil‐in‐water (O/W) microemulsion and varying the nature and concentration of CD additives as well as of the organic modifier (methanol, 2‐propanol or ACN) whilst keeping the applied voltage of 15 kV and capillary temperature of 30°C constant. The standard (O/W) microemulsion BGE solution consisted of 0.8% w/w octane, 6.6% w/w 1‐butanol, 2.0% w/w SDS and 90.6% w/w 10 mM sodium tetraborate buffer (pH 9.2). Enantioseparations with high resolution and short migration times of all tropa alkaloids were achieved by using heptakis(2,3‐di‐O‐methyl‐6‐O‐sulfo)‐β‐CD and sulfated β‐CD in the microemulsion BGE and were superior to corresponding CD‐modified CE methods.
Supratentorial primitive neuroectodermal tumors of the central nervous system frequently harbor deletions of the CDKN2A locus and other genomic aberrations distinct from medulloblastomas
Authors: Pfister Stefan , Remke Marc , Toedt Grischa , Werft Wiebke , Benner Axel , Mendrzyk Frank , Wittmann Andrea , Devens Frauke , von Hoff Katja , Rutkowski Stefan , Kulozik Andreas , Radlwimmer Bernhard , Scheurlen Wolfram , Lichter Peter , Korshunov Andrey 
Published: June 2007

AbstractSupratentorial primitive neuroectodermal tumors (stPNETs) and medulloblastomas have long been thought to arise from a common cell type in the subventricular germinal matrix. Because of the infrequent occurrence of stPNETs, little is known about their genetic background. Here, we performed a genome‐wide screening for DNA copy‐number aberrations in 10 supratentorial PNETs using array‐based comparative genomic hybridization (array‐CGH). Comparing our findings with data from a previous array‐CGH study on 47 medulloblastomas, we identified differences in the frequency of copy‐number losses at chromosome regions 1p12‐22.1 and 9p, and gains at 19p, all of them more frequently occurring in stPNETs. In contrast to previous reports, we detected chromosome 17 aberrations by array‐CGH in 2/10 stPNETs. To validate our findings obtained by array‐CGH, we analyzed the loci of interest by fluorescence in situ hybridization in an independent set of 11 stPNETs and found deletions of 9p21 in 5/11 tumors of the second set, three of them being homozygous. All 9p21 deletions were associated with loss of CDKN2A protein expression. Altogether, CDKN2A deletions were detected in 7/21 stPNETs including four homozygous deletions, whereas such deletions were only found in 4/112 medulloblastomas, all of these being heterozygous (P < 0.001). Gains of 19p (14% vs. 0% in medulloblastomas, P = 0.02) were found to be significantly more frequent in stPNETs, whereas gains of 17q (14% vs. 45% in medulloblastomas, P = 0.02) were confirmed to be more frequent in medulloblastomas. These data further support the hypothesis of two different tumor entities of embryonal neuroepithelial tumors with characteristic genetic aberrations. © 2007 Wiley‐Liss, Inc.
Performance of the general circulation HadAM3P model in simulating circulation types over the Mediterranean region
Authors: Anagnostopoulou CHR. , Tolika K. , Maheras P. , Kutiel H. , Flocas H. A. 
Published: June 2007

AbstractThe capability of the general circulation model(GCM) Hadley Center atmospheric general circulation model 3P (HadAM3P) to reproduce the mean pattern and the frequency of circulation types concerning the 500 hPa geopotential height fields and 1000–500 hPa thickness fields over Europe and the Mediterranean region are evaluated against the NCEP/NCAR dataset for the period 1960–1990. Daily catalogues of the circulation types describing the regional circulation over Greece at the 500 hPa and 1000–500 hPa thickness fields are constructed based on the two datasets, and the corresponding seasonal frequencies are also estimated. The evaluation is performed for the mean seasonal fields of the two parameters, as well as for those derived for each circulation type separately. It is demonstrated that the HadAM3P model generally succeeds in reproducing the two fields over the examined area, while their seasonal variability is underestimated. The mean patterns of the circulation types are well represented by the model but the seasonal simulated frequencies of the circulation types are not in good agreement with the national centers for environmental predictions (NCEP) ones. The systematic errors of the frequency estimation and the variability in some anticyclonic or cyclonic types should be considered seriously, because it can introduce some degree of uncertainty in the results of a downscaling method based on a circulation type approach. Nevertheless, the links between the precipitation, temperature and circulation types frequency seem to hold in the GCMs. It is therefore safe to use the frequencies of circulation types as predictor in a downscaling technique in order to obtain future precipitation and temperature. Copyright © 2007 Royal Meteorological Society
Determinants of small trading companies' performance in high‐tech industries
Authors: Li Lee , Ng Peggy , Gaber Brian 
Published: June 2007

AbstractSmall trading companies in high‐tech industries have experienced increasingly high failure rates in the last decade. Their threats result from the prevalence of the Internet, short product life cycles, frequent product replacements, and high inventory risks. This study explores the strategies adopted by small trading companies to survive competition in high‐tech industries. Findings from this study suggest that small trading companies in high‐tech industries should operate in a variety of markets and product lines, focus on manufacturers that adopt differential pricing policy, provide customers with bundles of products and complementary services, and continuously innovate new methods of distribution or transactions. These strategies help small trading companies sustain their value‐adding contributions in the distribution process. © 2007 Wiley Periodicals, Inc.
Old technology meets new technology: complementarities, similarities, and alliance formation
Authors: Rothaermel Frank T. , Boeker Warren 
Published: June 2007

AbstractAlliance formation is commonplace in many high‐technology industries experiencing radical technological change, where established firms use alliances with new entrants to adapt to technological change, while new entrants benefit from the ability of established players to commercialize the new technology. Despite the prevalence of these alliances, we know little about how these firms choose to ally with specific firms given the range of possible partners they may choose from. This study explores factors that lead to alliance formation between pharmaceutical and biotechnology companies. We focus on the alliance tie as the unit of analysis and argue that dyadic complementarities and similarities directly influence alliance formation. We then introduce a contingency model in which the positive effect of complementarities and similarities on alliance formation is moderated by the age of the new technology firm. We draw theoretical attention to the intersection between levels of analysis, in particular, the intersection between dyadic and firm‐level constructs. We find that a pharmaceutical and a biotechnology firm are more likely to enter an alliance based on complementarities when the biotechnology firm is younger. Another noteworthy finding is that proxies for broad capabilities appear to be at least as effective, if not more so, in predicting alliance formation compared to fine‐grained science and technology‐related indicators, like patent cross‐citations or patent common citations. We conclude by suggesting that future studies on alliance formation need to take into account interactions across levels; for example, how dyadic capabilities interact with firm‐level factors, and the advantages and disadvantages of more or less fine‐grained measures of organizational capabilities. Copyright © 2007 John Wiley & Sons, Ltd.
Chlamydia screening: the role of general practice
Authors: Emmett, Lynsey , Battison Teresa , Clarke, Janette 
Published: June 2007

AbstractThe English National Chlamydia Screening Programme is an important public health intervention that has the potential to make a substantial difference to the sexual health of young people. The authors outline practical ways in which general practice can help to make this a reality. Copyright © 2007 Wiley Interface Ltd
Scaled Quantum Mechanical Force Fields for the CF3SX Molecules (X = H, F, Cl, Br, I)
Authors: Ledesma A. E. , Brandán S. A. , Varetti E. L. , Ben Altabef A. 
Published: June 2007

AbstractDensity functional theory calculations at different levels of theory were performed on the molecules of the series CF3SX (X = H, F, Cl, Br, I) in order to obtain their optimized geometric parameters and conformations, the wavenumbers corresponding to the normal modes of vibrations and the associated force constants. The obtained force fields were transformed to local symmetry coordinates and scaled to reproduce the experimental wavenumbers.
Spontaneous maxillary sinus rupture in the absence of pre-existing sinus disease: case report
Authors: Beaumont H , Sharma N , Ahmed S K , O'Connell J E 
Published: June 2007

AbstractIntroduction:Spontaneous fracture of the maxillary sinus is usually associated with enophthalmos and pre-existing sinus disease.Case report:We present a case of spontaneous maxillary sinus fracture without enophthalmos and with no preceding history of trauma or evidence of sinusitis.Discussion:The closest condition to that presented is silent sinus syndrome. The differences between our case and this syndrome are reviewed. There are no previously reported cases of lateral wall maxillary fracture and associated facial surgical emphysema following nose-blowing.
Differential regulation of Akt, caspases and MAP kinases underlies smooth muscle cell apoptosis during aortic remodelling in SHR treated with amlodipine
Authors: Duguay D , DeBlois D 
Published: June 2007

Background and purpose:The regression of aortic hypertrophy is initiated by a transient wave of smooth muscle cell (SMC) apoptosis in spontaneously hypertensive rats (SHR) treated with antihypertensive drugs, although the molecular pathways remain unclear.Experimental approach:Enzymes involved in apoptosis regulation were examined daily during onset aortic remodelling in SHR treated with amlodipine (20 mg kg−1day−1).Key results:Significant reduction of aortic SMC number occurred by day 3 of amlodipine, reaching ‐13% at 28 days, followed by a significant regression of medial hypertrophy by day 5, reaching ‐13% at 28 days. ISOL‐positive (apoptotic) SMC nuclei increased by 4.6‐fold between days 2 and 4, in temporal correlation with the activation of caspase‐8 (2.7‐fold) at day 2 only, caspase‐3 at days 3 and 4 (1.7‐fold) and caspase‐9 at day 3 only (3.1‐fold). Akt phosphorylation, a pro‐survival pathway, was reduced prior to apoptosis at day 1 (‐52%) and until day 3. During the first 6 days of amlodipine treatment, significant reduction in phosphorylation of mitogen‐activated protein (MAP) kinases was transient for p38 (‐46% at day 3 only) but continuous for ERK1/2 after 3 days (‐40%), and for JNK after 4 days (>‐50%).Conclusions and implications:Amlodipine inhibition of Akt occurred prior to and during SMC apoptosis induction, a process mediated by the early activation of caspase‐8 followed by caspase‐9 and ‐3 and associated with MAP kinase inhibition. These findings provide insights about the molecular pathways underlying SMC apoptosis leading to vascular remodelling during amlodipine treatment of hypertension.British Journal of Pharmacology(2007)151, 1315–1323; doi:10.1038/sj.bjp.0707334
Tuning the endocannabinoid system: allosteric modulators of the CB1 receptor
Authors: Ross R A 
Published: June 2007

Cannabinoid CB1 receptor antagonists are novel therapeutics with potential for the treatment of a number of conditions including obesity, nicotine addition and metabolic syndrome. In 2005, Price et al. demonstrated that the cannabinoid CB1 receptor contains an allosteric‐binding site which binds synthetic small molecules. In this issue of the British Journal of Pharmacology, Horswill et al. have extended these observations. They demonstrate that a structurally similar small molecule allosterically modulates the cannabinoid CB1 receptor and reduces body weight and food intake in an acute feeding model. Allosteric modulation now contends as a new strategy in the therapeutic exploitation of cannabinoid receptors that may offer certain advantages over the more familiar small molecules targeting the orthosteric site.British Journal of Pharmacology (2007) 152, 565–566; doi:10.1038/sj.bjp.0707349; published online 25 June 2007
Medical-Care Costs Associated with Posttraumatic Stress Disorder in Vietnam Veterans
Authors: Marshall Richard P. , Jorm Anthony F. , Grayson David A. , O'Toole Brian I. 
Published: June 2007

Objective: This study examined the relationship between medical-care costs of Vietnam veterans and predictor factors, including posttraumatic stress disorder (PTSD). Method: We merged medical-care cost data from the Department of Veterans' Affairs and the Health Insurance Commission with data from an epidemiological study of 641 Australian Vietnam veterans. Posttraumatic stress disorder and other factors were examined as predictors of medical-care cost using regression analysis. Results: We found that a diagnosis of PTSD was associated with medical costs 60% higher than average. Those costs appeared to be partly associated with higher treatment costs for physical conditions in those with PTSD and also related mental health comorbidities. Major predictors of medical-care cost were age ($137 per year for each 5-year increase in age) and number of diagnoses reported ($81 to $112 per year for each diagnosis). Mental health factors such as depression ($14 per year for each symptom reported) and anxiety ($27 per year for each symptom reported) were also important predictors. Conclusions: The findings indicate that, however they are incurred, high healthcare and, presumably, also economic and personal costs are associated with PTSD. There is an important social obligation as well as substantial economic reasons to deal with these problems. From both perspectives, continued efforts to identify and implement effective prevention and treatment programs are warranted.
Lifetime Prevalence of Trauma among Homeless People in Sydney
Authors: Buhrich Neil , Hodder Tracey , Teesson Maree 
Published: June 2007

Objective: The experience of lifetime trauma among homeless women in the USA is well documented. Less information is available concerning homeless men. There are no prevalence studies concerning lifetime trauma among homeless people in Australia. Our aim was to assess the lifetime prevalence of trauma as reported by homeless men and women in Sydney. Method: We interviewed 119 men and 38 women who were visiting or residing at the seven largest refuges for homeless people in inner Sydney, using the lifetime trauma section of the Composite International Diagnostic Interview. Results: All women and over 90% of men reported at least one event of trauma in their life. Fifty-eight per cent suffered serious physical assault and 55% witnessed someone being badly injured or killed. Half the women and 10% of men reported that they had been raped. Conclusion: The experience of at least one lifetime event of trauma is almost universal among homeless people in Sydney and is considerably higher than for the USA general population. Reasons for such high prevalence rates are discussed. Depression and posttraumatic stress disorder are associated with a history of trauma. Health professionals need to be aware of past events of trauma among individuals who are homeless.
Neuroleptic and Anticholinergic Drug Use in Chinese Patients with Schizophrenia Resident in a State Psychiatric Hospital in Singapore
Authors: Chong Siow-Ann , Sachdev Perminder , Mahendran Rathi , Chua Hong-Choon 
Published: June 2007

Objective: The objective of this study was to survey the prescribing pattern in Chinese patients with chronic schizophrenia in a state mental hospital in Singapore, and to compare our findings with those of surveys of Chinese patients in other countries. Method: We surveyed the use of neuroleptic and anticholinergic agents among Chinese patients with chronic schizophrenia (n = 534) in a state mental hospital in Singapore. Results: Fifty-nine per cent of the patients received two or more neuroleptics (median daily dose of 400 mg chlorpromazine equivalents, range 50–2875 mg). There were no differences in gender distribution between those prescribed multiple neuroleptics as against an older group of those receiving none or only one neuroleptic medication. Sixty-six per cent of the patients were receiving depot neuroleptics, with more than half of these subjects also receiving additional oral neuroleptics. Patients who were prescribed multiple neuroleptics received significantly higher total doses than those receiving just one neuroleptic. Only 1% of patients were prescribed an atypical neuroleptic. Sixty-five per cent of patients were prescribed an anticholinergic agent. Those prescribed anticholinergic agents were younger, in receipt of higher doses of neuroleptic medications and had lower Simpson-Angus scores for extrapyramidal side-effects. Conclusions: The pervasive use of multiple typical neuroleptics, marked under-utilisation of atypical neuroleptics, and the lack of anticholinergic medication in patients who might benefit from such treatment are issues of substantial concern, warranting action in both psychiatry practice and mental health policy.
The Impact Factor: Time for Change
Authors: Bloch Sidney , Walter Garry 
Published: June 2007

Objective: The Impact Factor (IF) has received virtually no attention in the psychiatric literature, despite its long-term use, expanding influence and evidence of misapplication. We examine the IF's validity as a measure of a paper's scientific worth, and consider alternative ways to conduct such an appraisal. Method: We explored medical databases and websites, and conferred with acknowledged experts on the subject. Results: Irremediable problems, both conceptual and technical, make the IF a flawed measure. The notion that citations vouch for the quality of an article is questionable. Moreover, the IF's vulnerability to misuse in domains such as academic promotion and research grant assessment is a serious development. Conclusion: The IF (and all measures derived from it) should be abandoned. A ‘return to basics’ in evaluating published work is overdue. As seductive as a simple formula is to assess quality, shortcuts are unavailable and unlikely to be useful. Publishing a short-list of papers annually, judged as objectively as possible by peers to merit special attention, may be a more meaningful option. Conceivably, every psychiatric journal could participate in this cyclical exercise, leading to a ‘grand short-list’. This could be made readily available to all professionals, both researchers and clinicians, by being posted on a suitable website. Since peer review has a long-standing role in scientific publishing, our proposal is essentially an extension of that process.