bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of ab initio and group additive ideal gas heat capacities
Authors: Marriott Robert A. , White Mary Anne 
Published: December 2004

AbstractThree case studies comparing molecular ideal gas heat capacity estimations using empirical group additive methods and statistical mechanical methods using ab initio vibrational frequencies are reported. In the first study, results from several ab initio levels of theory are compared with the experimental heat capacities of piperidine and the heat capacities calculated from the observed vibrational frequencies. In the second study, heat capacities for a benchmark group of 27 organic molecules were calculated using vibrational frequencies from AM1, HF/3‐21G(d), and B3LYP/6‐31G(d) theory level, and the results were compared to three recently updated additivity schemes. In the third study, semiempirical corrections to the heat capacities of n‐alkanes were investigated. The strength of additivity schemes is that they are easy to use and understand, and often give reasonable results, but predict the same thermodynamic properties for isomers containing the same functional groups, and are of limited accuracy when the near‐neighbor interactions are strong or if the input data set is not appropriate. Ab initio vibrational frequencies can rapidly provide accurate heat capacities using the harmonic oscillator model, especially if one conformer dominates. The results can be comparable to additivity, and better for rigid molecules containing heteroatoms. Furthermore, ab initio results do not require a calibration data set. © 2004 American Institute of Chemical Engineers AIChE J, 51: 292–297, 2005
Study of folate receptor genes in nonsyndromic familial and sporadic cleft lip with or without clef palate cases
Authors: Scapoli Luca , Marchesini Jlenia , Martinelli Marcella , Pezzetti Furio , Carinci Francesco , Palmieri Annalisa , Rullo Rosario , Gombos Fernando , Tognon Mauro , Carinci Paolo 
Published: December 2004

AbstractFolate receptor family members (FOLRs) mediate the delivery of 5‐methyltetrahydrofolate to the interior of, out of within, or between cells in a process known as potocytosis. Three FOLRs and a pseudogene map to 11q13.4. The aim of this study was to verify whether FOLRs could be responsible for the onset of nonsyndromic cleft lip with or without cleft palate (CL/P). Linkage and linkage disequilibrium between genetic markers and disorder were analyzed. Patients and their mothers from 71 familial CL/P pedigrees and 75 sporadic cases from Italian population were investigated by PCR‐SSCP analysis. Data from mutation scanning allowed us to find only a silent mutation in FOLR1 present in a mother and her child. Our findings do not support FOLR1 and FOLR2 genes in the onset of CL/P. © 2004 Wiley‐Liss, Inc.
Chronic exposure to a 1.439 GHz electromagnetic field used for cellular phones does not promote N‐ethylnitrosourea induced central nervous system tumors in F344 rats
Authors: Shirai Tomoyuki , Kawabe Mayumi , Ichihara Toshio , Fujiwara Osamu , Taki Masao , Watanabe So‐ichi , Wake Kanako , Yamanaka Yukio , Imaida Katsumi , Asamoto Makoto , Tamano Seiko 
Published: December 2004

AbstractThe present study was designed to evaluate whether a 2 year exposure to an electromagnetic field (EMF) equivalent to that generated by cellular phones can accelerate tumor development in the central nervous system (CNS) of rats. Brain tumorigenesis was initiated by an intrauterine exposure to N‐ethylnitrosourea (ENU) on gestational day 18. A total of 500 pups were divided into five groups, each composed of 50 males and 50 females: Group 1, untreated control; Group 2, ENU alone; Groups 3–5, ENU + EMF (sham exposure and 2 exposure levels). A 1.439 GHz time division multiple access (TDMA) signal for the Personal Digital Cellular (PDC), Japanese standard cellular system was used for the exposure of the rat head starting from 5 weeks of age, 90 min a day, 5 days a week, for 104 weeks. Brain average specific absorption rate (SAR) was 0.67 and 2.0 W/kg for low and high exposures, respectively: whole body average SAR was less than 0.4 W/kg. There were no inter‐group differences in body weights, food consumption, and survival rates. No increase in the incidences or numbers per group of brain and/or spinal cord tumors, either in the males or females, was detected in the EMF exposed groups. In addition, no clear changes in tumor types were evident. Thus, under the present experimental conditions, 1.439 GHz EMF exposure to the heads of rats for a 2 year period was not demonstrated to accelerate or affect ENU initiated brain tumorigenesis. Bioelectromagnetics 26:59–68, 2005. © 2004 Wiley‐Liss, Inc.
The discursive construction of community identity
Authors: Colombo Monica , Senatore Azzurra 
Published: December 2004

AbstractThe aim of this article is to illustrate how a discourse‐oriented approach would open new theoretical and methodological perspectives to the study of community identity. Here outlined is the idea that community identity is discursively constructed by members in order to lend meaning to experience. An analysis of how community identity is constructed in subjects' discourse with reference to the local context is presented. Copyright © 2004 John Wiley & Sons, Ltd.
Synthetic Strategies for Controlling the Morphology of Proton Conducting Polymer Membranes
Authors: Yang Y. , Holdcroft S. 
Published: December 2004

AbstractThe nanostructure and morphology of proton conducting polymers is of considerable interest in the search for next generation materials and optimization of existing ones. Synthetic methodologies for tailoring molecular structures that promote nanoscopic phase separation of ionic and non‐ionic domains, and the effect of phase separation on parameters such as proton conductivity, are considered. Rather than distinguish proton conducting polymers according to chemical class, they are categorized under sub‐headings of random, block, and graft copolymers. The synthetic methodology available to access archetypal polymer structures is dependent on the nature of the monomers and restrictive compared to conventional non‐ionic polymer systems. Irrespective of the methodology, ionic aggregation and phase separation are consistently found to play an important role in the proton conductivity of low ion exchange capacity (IEC) membranes, but less of a role in highIECmembranes. Significant research is required to further develop relationships between polymer architecture, morphology, and electrolytic properties.
Pharmacoeconomic evaluation and healthcare management in Poland
Authors: Czech Marcin 
Published: December 2004

AbstractThe main objective of this study was to investigate the potential role of pharmacoeconomic evaluation in the decision‐making process and management in healthcare in Poland. A group of 102 people with backgrounds in health economics/pharmacoeconomics was interviewed, including students (23), medical doctors (28), pharmacists (36), managers/economists (22). They came from such settings as hospitals, outpatient clinics, pharmacies, and the pharmaceutical industry. They were asked about sources of information that should be used by decision makers at different levels of healthcare sector, barriers to practical application of pharmacoeconomic evaluation results, criteria for inclusion/exclusion of drugs in a hospital formulary, means by which economic evaluation utilization could become more common, and finally about needs for education initiatives. Eighty six percent of respondents indicated that expert opinion and 66% that articles in reviewed scientific journals are the most important source of information for reimbursement decisions. At management level, expert opinion (77%) and scientific journals (65%) were also considered as an important source of information. In relations between the pharmacist/physician and patient, personal opinion was found to be vital (58%), followed by an expert opinion (55%), and by information from the scientific press (50%). As main barriers, interviewees recognized limited interest in pharmacoeconomic analyses focusing only on cost‐containment (77%) followed by lack of governmental agency involvement in introduction of the regulations (61%), difficulties in applying long‐term view (57%), and limited access to cost data (lack of national cost database) (57%). The survey results showed that acquisition cost (70%) and efficacy (96%) were considered to be crucial, while hospital savings were less important (50%). Also, a wider use of pharmacoeconomic studies may result from more educational initiatives (74%), creation of professional cost databases (72%), and transparent criteria of evaluation (69%). Eighty six percent of respondents expressed the desire to expand their current knowledge in the relevant areas of interest. © 2005 Wiley Periodicals, Inc. Hum Factors Man 15: 99–108, 2005.
Organizational entrepreneurship: Theoretical background, some empirical tests, and directions for future research
Authors: Bratnicki Mariusz 
Published: December 2004

AbstractThe widely held contemporary perspective on entrepreneurship is dangerously premature. Currently existing theories are insufficient to understand the dynamic interplay among entrepreneurship, the state, and external environment forces, as well as the organization's capacity to facilitate entrepreneurship and resulting effectiveness. In this exploratory paper I identify organizational architecture variables that help to shape a firm's entrepreneurship. The topic of organizational enablers is introduced. The primary purpose of the investigation falls under a category of exploration of dialectics' potential for entrepreneurship theory and development concept that refers to strategic contradictions, organizational enablers, and entrepreneurial behaviors. In particular, it focuses on understanding the organizational context of entrepreneurship and understanding the entrepreneurial reconciliation made by managers who seek to increase their company's growth. I investigate empirically how reconciliation of primary and secondary contradictions is related to entrepreneurial behaviors. The in‐depth examination of organizational enablers and entrepreneurial behavior is only one example of how a dialectical approach can reshape our understanding of the complex, multilevel entrepreneurship process, which may have less to do with the behavior of individual members than with impersonal and seemingly insignificant forces. Finally, implications for future research are discussed. © 2005 Wiley Periodicals, Inc. Hum Factors Man 15: 15–33, 2005.
Building entrepreneurial capacity in post‐communist Poland: A case study
Authors: Despiney Barbara A. 
Published: December 2004

AbstractThe process of globalization defines new frontiers, giving more importance to the territory. In the context of a rapidly changing international environment it is of no small importance to ask questions about the present situations in the bordering regions, their foreseeable evolution, both short‐ and long‐term, and the economic and social consequences likely to result, considering their geographical and demographic situation, as well as their structures of activity. The redrawing of old national territories no longer seems to be the product of diplomacy and, in particular, wars; henceforth, it would appear to depend upon industrial economics. This is especially significant in the case of “Neisse,” the Euroregion located on Polish–Czech–German borders. Here is the chance to revive a localized productive system that would give life to new forms of interregional cooperation. In this article I reflect on the relevance of the Marshallian district concept in the analysis of this interregional cooperation. The Marshallian industrial district is based on the external economies of agglomerations and the economics of urbanization, and this kind of development we can see today in Poland. The study of localized productive systems must be thorough, multidisciplinary, and carried out through fieldwork. The aim is to understand how work, relationships, and culture as well as material and immaterial infrastructures, which give a place for original identity within the international division of labor, regenerate in locally coherent forms. A production system grouped together on a spatial level and integrated company networks at the regional level could serve to create local hubs of competition in Central and Eastern Europe. © 2005 Wiley Periodicals, Inc. Hum Factors Man 15: 109–126, 2005.
Influence of the power density on the kinetics of photopolymerization and properties of dental composites
Authors: Neves A. D. , Discacciati J. A. C. , Oréfice R. L. , Yoshida M. I. 
Published: December 2004

AbstractPolymer shrinkage during photopolymerization of dimethacrylate monomers, used for many years to produce materials for dental restoration, can induce either the formation of tooth‐restoration gaps or the production of residual stress depending on the quality of adhesion between tooth and dental composites. In this work, the effect of the power density, used to photopolymerize three commercial dental composites (Fill Magic, Supra Fill, and Z100), on the kinetics of the reaction was investigated to determine processing conditions in which the generation of residual stress would be reduced by allowing polymer chains and macromers to flow before freezing during gelation of the polymer network. The kinetics of photopolymerization of the dental composites was monitored by real‐time infrared (FTIR) spectroscopy. Polymer shrinkage and mechanical properties were also investigated by using, respectively, density and microhardness measurements. Results showed that the final conversion (after 200 s), volumetric shrinkage, and microhardness values were not affected by different power densities, mainly because the amount of energy used during photopolymerization was set constant by using different irradiation times. Lower power densities were able to reduce the maximum polymerization rate and delay the formation of a rigid network. Conversion before the formation of the rigid network was also enhanced by using a lower power density. Considering that too premature gelation can lead to residual stress during shrinkage, the results of this work indicated that the use of a lower power density can be effective in terms of delaying the onset of the formation of a rigid network, providing then conditions for macromolecules to flow and relieve stress during shrinkage. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 72B: 393–400, 2005
Gas6 induces proliferation in prostate carcinoma cell lines expressing the Axl receptor
Authors: Sainaghi Pier Paolo , Castello Luigi , Bergamasco Luca , Galletti Margherita , Bellosta Paola , Avanzi Gian Carlo 
Published: December 2004

AbstractAxl is a tyrosine kinase receptor and although it is expressed in malignancy such as leukemia, colon cancer, melanoma, endometrial, prostate and thyroid cancers, its role has not been completely elucidated yet and appears to be complex. The ligand of Axl, Gas6, is a 75 KDa multimodular protein with an N‐terminal gamma‐carboxy‐glutamic acid that is essential for binding. Gas6 has a mitogenic effect on several normal cell lines. The receptor Axl is expressed in primary prostate carcinoma and in prostate cancer cell lines as such as PC‐3 and DU 145. We demonstrated a mitogenic activity determined by Gas6/Axl interaction in these undifferentiated metastatic human prostatic cancer cell lines. This effect is proportional to Axl expression, not due to inhibition of apoptosis, and induces AKT and MAPK phosphorylation. However, only MEK phosphorylation seems to be essential for growth signaling. Our results suggest that Axl overexpression and activation by Gas6 could be involved in progression of prostate neoplastic disease. © 2004 Wiley‐Liss, Inc.
Volumetric flow mapping for microvascular networks by bimodality imaging with light microscope and laser doppler imager
Authors: Sun Ying , Verbeuren Tony J. , Vallez Marie O. , Nilsson Gert E. , Sjöberg Folke 
Published: December 2004

AbstractA method was developed to produce a composite image of microvascular networks with grayscales proportional to volumetric flows. Velocities in arterioles and venules were assessed with a high‐resolution laser Doppler imager (LDI). The vascular structures were quantified from the micrograph with a computerized vessel detection algorithm. After registering the detected vascular network with the LDI scan, volumetric flows were calculated along the centerlines of the vessels. In vivo data were obtained from the hamster cheek pouch in 6 studies. Flow continuity of the flow map was evaluated by comparing the main flow (Q) with the sum of branch flows (Qs), averaging over the respective vessel segments incident to each bifurcation. The method was reproducible across the 6 studies with the correlation coefficient (r) between Qs and Q ranging from 0.913 to 0.986. In all, over 20,000 flow estimates from 360 vessel segments (24–160 μm in diameter) at 166 bifurcations were analyzed. With flow normalized between 0 and 1, the linear regression yielded: Qs = 1.03 Q + 0.006; r = 0.952, n = 166, P < 0.0005. The bimodality imaging method exploits a large amount of velocity and diameter data, and therefore should be useful for studying heterogeneous flows in the microvasculature. Microsc. Res. Tech. 65:130–138, 2004. © 2004 Wiley‐Liss, Inc.
Defocusing microscopy
Authors: Agero U. , Mesquita L.G. , Neves B.R.A. , Gazzinelli R.T. , Mesquita O.N. 
Published: December 2004

AbstractTransparent objects (phase objects) are not visible in a standard brightfield optical microscope. In order to see such objects the most used technique is phase‐contrast microscopy. In phase‐contrast microscopy the contrast observed is proportional to the optical path difference introduced by the object. If the index of refraction is uniform, phase‐contrast microscopy then yields a measure of the thickness profile of phase objects. We show that by slightly defocusing an optical microscope operating in brightfield, phase objects become visible. We modeled such an effect and show that the image contrast of a phase object is proportional to the amount of defocusing and proportional to the two‐dimensional Laplacian of the optical path difference introduced by the object. For uniform index of refraction, defocusing microscopy then yields a measure of the curvature profile of phase objects. We extended our previous model for thin objects to thick objects. To check our theoretical model, we use as phase objects polystyrene spherical caps and compare their curvature radii obtained by defocusing microscopy (DM) to those obtained with atomic force microscopy (AFM). We also show that for thick curved phase objects one can reconstruct their thickness profiles from DM images. We illustrate the utility of defocusing microscopy in biological systems to study cell motility. In particular, we visualize and quantitatively measure real‐time cytoskeleton curvature fluctuations of macrophages (a cell of the innate immune system). The study of such fluctuations might be important for a better understanding of the engulfment process of pathogens during phagocytosis. Microsc. Res. Tech. 65:159–165, 2004. © 2004 Wiley‐Liss, Inc.
Changes in HIV RNA viral load, CD4+ T‐cell counts, and levels of immune activation markers associated with anti‐tuberculosis therapy and cotrimoxazole prophylaxis among HIV‐infected tuberculosis patients in Abidjan, Côte d'Ivoire
Authors: Kalou Mireille , Sassan‐Morokro Madeleine , Abouya Lucien , Bile Célestin , Maurice Chantal , Maran Mathieu , Tossou Odette , Roels Thierry , Greenberg Alan E. , Wiktor Stefan Z. , Nkengasong John N. 
Published: December 2004

AbstractWe analyzed changes in plasma human immunodeficiency virus (HIV)‐1 viral load, CD4+ T‐cell count, and markers of immune activation markers at start of treatment of tuberculosis and 12 months after among 44 HIV‐1‐infected patients with newly diagnosed, sputum‐smear positive for Mycobacterium tuberculosis pulmonary in fection. All patients received a standard regimen of 6 months of rifampicin and isoniazid with first 2 months of pyrazinamid with or without cotrimoxazole. Compared with values at start of treatment, median viral load increased by a median of 0.64 log10 copies/ml after 12 months of follow‐up (P = 0.0002). Median CD4+ T‐cell counts were 393 cells/L at start of treatment and 370 cells/L after 12 months of follow‐up (P = 0.61). Levels of serum activation markers decreased significantly at 12 months of follow‐up of the patients for both patients on standard and cotrimoxazole treatment. Levels of viral load, CD4+ T‐cell counts, and markers of immune activation were not different for patients on standard treatment of tuberculosis compared with those on standard and cotrimoxazole treatment. Levels of serum activation markers decreased significantly at 12 months of follow‐up of the patients for both patients on standard and cotrimoxazole treatment. Because viral load is a predictor of disease progression, its persistent elevated levels in blood of HIV‐infected patients co‐infected with tuberculosis, who successfully complete TB treatment, may account for the high mortality observed in this population. J. Med. Virol. 75:202–208, 2005. © 2004 Wiley‐Liss, Inc.
Productive herpes simplex virus in brain of elderly normal subjects and Alzheimer's disease patients
Authors: Wozniak Matthew A. , Shipley Suzanne J. , Combrinck Marc , Wilcock Gordon K. , Itzhaki Ruth F. 
Published: December 2004

AbstractIt was previously shown that herpes simplex virus type 1 (HSV1) DNA resides latently in a high proportion of aged brains and that in carriers of the type 4 allele of the apolipoprotein E gene (APOE‐ε4), it confers a strong risk of Alzheimer's disease. It was suggested that initial entry of brain by HSV1 and any subsequent reactivation(s) would cause a type of limited encephalitis, the resulting damage being more harmful in APOE‐ε4 carriers. Reactivation(s) would induce synthesis of intrathecal antibodies; these are long‐lived after herpes simplex encephalitis so they were sought in cerebrospinal fluid (CSF) of Alzheimer's disease patients and age‐matched normal subjects. Intrathecal antibodies to human herpesvirus 6 (HHV6) were also sought as DNA of this virus has been detected previously in a high proportion of Alzheimer's disease brains. Antibody indices for HSV and HHV6 were measured using indirect ELISA for IgG antibody, and single radial immunodiffusion was used for albumin, in serum and CSF. A raised antibody index (>1.5) indicative of virus‐specific intrathecal HSV1 IgG synthesis was found in 14/27 (52%) Alzheimer's disease patients and 9/13 (69%) age‐matched normals (difference non‐significant). A raised antibody index to HHV6 was detected in 22% of the Alzheimer's disease patients and in no normals, so presumably this virus either did not reactivate in brain or it elicited only short‐lived intrathecal antibodies. The HSV1 results confirm the original PCR findings that show the presence of HSV1 DNA sequences in many elderly brains, and indicate also that the whole functional HSV1 genome is present, and that the virus has replicated. J. Med. Virol. 75:300–306, 2005. © 2004 Wiley‐Liss, Inc.