bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymmetries in conditional mean and variance: modelling stock returns by asMA‐asQGARCH
Authors: Brännäs Kurt , Gooijer Jan G. De 
Published: April 2004

AbstractWe propose a nonlinear time series model where both the conditional mean and the conditional variance are asymmetric functions of past information. The model is particularly useful for analysing financial time series where it has been noted that there is an asymmetric impact of good news and bad news on volatility (risk) transmission. We introduce a coherent framework for testing asymmetries in the conditional mean and the conditional variance, separately or jointly. To this end we derive both a Wald and a Lagrange multiplier test. Some of the new asymmetric model's moment properties are investigated. Detailed empirical results are given for the daily returns of the composite index of the New York Stock Exchange. There is strong evidence of asymmetry in both the conditional mean and the conditional variance functions. In a genuine out‐of‐sample forecasting experiment the performance of the best fitted asymmetric model, having asymmetries in both conditional mean and conditional variance, is compared with an asymmetric model for the conditional mean, and with no‐change forecasts. This is done both in terms of conditional mean forecasting as well as in terms of risk forecasting. Finally, the paper presents some evidence of asymmetries in the index stock returns of the Group of Seven (G7) industrialized countries. Copyright © 2004 John Wiley & Sons, Ltd.
Information on ancestry from genetic markers
Authors: Pfaff Carrie Lynn , Barnholtz‐Sloan Jill , Wagner Jennifer K. , Long Jeffrey C. 
Published: April 2004

AbstractIt is possible to estimate the proportionate contributions of ancestral populations to admixed individuals or populations using genetic markers, but different loci and alleles vary considerably in the amount of information that they provide. Conventionally, the allele frequency difference between parental populations (δ) has been used as the criterion to select informative markers. However, it is unclear how to use δ for multiallelic loci, or populations formed by the mixture of more than two groups. Moreover, several other factors, including the actual ancestral proportions and the relative genetic diversities of the parental populations, affect the information provided by genetic markers. We demonstrate here that using δ as the sole criterion for marker selection is inadequate, and we propose, instead, to use Fisher's information, which is the inverse of the variance of the estimated ancestral contributions. This measure is superior because it is directly related to the precision of ancestry estimates. Although δ is related to Fisher's information, the relationship is neither linear nor simple, and the information can vary widely for markers with identical δs. Fortunately, Fisher's information is easily computed and formally extends to the situation of multiple alleles and/or parental populations. We examined the distribution of information for SNP and microsatellite loci available in the public domain for a variety of model admixed populations. The information, on average, is higher for microsatellite loci, but exceptional SNPs exceed the best microsatellites. Despite the large number of genetic markers that have been identified for admixture analysis, it appears that information for estimating admixture proportions is limited, and estimates will typically have wide confidence intervals. © 2004 Wiley‐Liss,Inc.
FK506 enhances regeneration of axons across long peripheral nerve gaps repaired with collagen guides seeded with allogeneic Schwann cells
Authors: Udina Esther , Rodríguez Francisco J. , Verdú Enrique , Espejo Mónica , Gold Bruce G. , Navarro Xavier 
Published: April 2004

AbstractWe assessed the effects of FK506 administration on regeneration after a 6‐mm gap repair with a collagen guide seeded with allogeneic Schwann cells (SCs) in the mouse sciatic nerve. SCs were isolated from predegenerated adult sciatic nerves and expanded in culture using a defined medium, before being seeded in the collagen guide embedded in Matrigel. Functional reinnervation was evaluated by noninvasive methods to determine recovery of motor, sensory, and autonomic functions in the hindpaw over 4 months postoperation. Histological analysis of the regenerated nerves was performed at the end of the study. Using simple collagen guides for tubulization repair, treatment with an immunosuppressant dose of FK506 (5 mg/kg/day) resulted in significant improvement of the onset and the degree of reinnervation. While the introduction of allogeneic SCs did not improve regeneration versus a collagen guide filled only with Matrigel, treatment with FK506 allowed for successful regeneration in all the mice and for significant improvement in the levels of functional recovery. Compared with the untreated group, there was greater survival of transplanted pre‐labeled SCs in the FK506‐treated animals. Morphologically, the best nerve regeneration (in terms of nerve caliber and numbers of myelinated axons) was obtained with SC‐seeded guides from FK506‐treated animals. Thus, FK506 should be considered as adjunct therapy for various types of tubulization repair. © 2004 Wiley‐Liss, Inc.
Migratory capacity of the cell line RN33B and the host glial cell response after subretinal transplantation to normal adult rats
Authors: Blixt Wojciechowski Anita , Englund Ulrica , Lundberg Cecilia , Warfvinge Karin 
Published: April 2004

AbstractAs previously reported, the brain‐derived precursor cell line RN33B has a great capacity to migrate when transplanted to adult brain or retina. This cell line is immortalized with the SV40 large T‐antigen and carries the reporter gene LacZ and the green fluorescent protein GFP. In the present study, the precursor cells were transplanted to the subretinal space of adult rats and investigated early after grafting. The purpose was to demonstrate the migration of the grafted cells from the subretinal space into the retina and the glial cell response of the host retina. Detachment caused by the transplantation method was persistent up to 4 days after transplantation, and then reattachment occurred. The grafted cells were shown to migrate in between the photoreceptor cells before entering into the plexiform layers. Molecules involved in migration of immature neuronal cells as the polysialylated neural cell adhesion molecule (PSA‐NCAM) and the collapsing response‐mediated protein 4 (TUC‐4) was found in the plexiform layers of the host retina, but not in the grafted cells. The expression of the intermediate filaments GFAP, vimentin, and nestin was intensely upregulated immediately after transplantation. A less pronounced upregulation was observed on sham‐operated animals. In summary, the RN33B cell line migrated promptly posttransplantation and settled preferably into the plexiform layers of the retina, the same layers where the migration cues PSA‐NCAM and TUC‐4 were established. In addition, both the transplantation method per se and the implanted cells caused an intense glial cell response by the host retina. © 2004 Wiley‐Liss, Inc.
Cycloaddition reactions of heterophospholes
Authors: Bansal Raj K. , Gupta Neelima , Gupta Nidhi 
Published: April 2004

AbstractThe cycloaddition reactions namely, [2 + 4], [4 + 2], [2 + 3] and [1 + 4] given by the heterophospholes, which are five‐membered 6π aromatic heterocycles containing at least one σ2, λ3 phosphorus, are reviewed in the present article. Different aspects of these reactions such as stereoselectivity, regioselectivity, relative reactivities and theoretical correlations thereof are included. The literature has been surveyed up to December 2003. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:271–287, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20002
The first general synthesis of 3‐iodo‐4‐R‐furazans
Authors: Sheremetev Aleksei B. , Shamshina Julia L. , Dmitriev Dmitry E. , Lyubetskii Denis V. , Antipin Mikhail Yu. 
Published: April 2004

AbstractThe first general synthetic route has been developed for the convenient preparation of iodofurazans. The approach was accomplished by one‐pot diazotization‐iodation reaction of appropriate aminofurazans. A combination of sodium nitrite and iodine in organic solvent under anhydrous conditions as the reaction conditions allowed to solve problem in iodofurazans preparation. The investigation of the substituent's influence on NMR data of the iodofurazans has been carried out. The X‐ray crystal structure of the 3‐amino‐4‐iodofurazan 1d is reported. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:199–207, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20007
Design of novel podand‐like compounds with two short diphenylphosphine oxide pendant arms
Authors: Kruszynski Rafal , Wieczorek Wanda 
Published: April 2004

AbstractCrystal and molecular structure of 1,3,5‐benzenetris(methylenediphenylphosphine oxide) cyclohexylammonium chloride dibenzene solvate monohydrate has been determined. The overall arrangement of two diphenylphosphine oxide substituents atoms is imposed by intermolecular strong hydrogen bonds, O(water)H···O(oxide) and NH···O(oxide, water). Cyclohexylamine exists in almost ideal chair conformation and nitrogen atom is equatorial to the ring. The structure is build up from strong and weak intermolecular hydrogen bonds to form the three‐dimensional infinite hydrogen bond network.Crystal and molecular structure of 1,4‐bis[(diphenylphosphineoxide)methyl] ‐ 2,5 ‐ bis (ethoxymethyl) benzene has been determined. The phenyl rings are inclined at 80.91(7)° within the substituent, and they are involved in weak C(phenyl)H···O(oxide) hydrogen bonds. The arrangement of diphenylphosphine oxide substituents is imposed practically only by steric effects. Two intramolecular weak hydrogen bonds exist between diphenylphosphine oxide and ethoxymethyl substituents, which can provide additional stabilization to molecule, but it has no noticeable influence on overall molecule geometry. Molecules are assembled via weak intermolecular CH···O(oxide) hydrogen bonds to the one‐dimensional hydrogen‐bonded chain along y axis. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:233–240, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20008
Quantum chemical estimation of reactivity of 2,3,4,5‐tetrahydro‐1,5‐benzodiazepin‐2(1H)‐ones in electrophilic aromatic substitution
Authors: Vektariene Ausra , Vektaris Gytis 
Published: April 2004

AbstractDFT B3LYP calculation study was employed to estimate the regioselectivity of an electrophilic aromatic substitution in functionalized 2,3,4,5‐tetrahydro‐1,5‐benzodiazepin‐2(1H)‐ones. Charge density, frontier molecular orbital study, energetics of σ‐complex intermediates of electrophilic substitution reactions in the 2,3,4,5‐tetrahydro‐1,5‐benzodiazepin‐2(1H)‐ones yield information on different reactivity of aromatic sites. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:263–270, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20015
High‐resolution imaging of the thyroid gland using optical coherence tomography
Authors: Pantanowitz Liron , Hsiung Pei‐Lin , Ko Tony H. , Schneider Karl , Herz Paul R. , Fujimoto James G. , Raza Sughra , Connolly James L. 
Published: April 2004

AbstractBackground.Current diagnostic imaging modalities of the thyroid gland cannot reliably distinguish benign from malignant lesions, primarily because of their inability to visualize microscopic structure. A high‐resolution imaging technique capable of examining thyroid tissue architectural morphology in real time is needed. Optical coherence tomography (OCT) has been shown to achieve high resolutions approaching the cellular range (1–15 μm). The feasibility of optical coherence tomography for imaging thyroid tissue was explored ex vivo on the human thyroid gland.Methods.High‐resolution OCT was performed in real time at 2 to 4 frames per second on three postmortem and 15 surgically excised thyroid glands containing normal, hyperplastic, and neoplastic tissue. OCT images acquired were compared with those obtained using standard histopathologic methods.Results.The microstructure of the normal thyroid gland, including colloid‐filled follicles as small as 15 μm and their supporting stroma, was clearly identified. OCT images of degenerative, hyperplastic, adenomatous, and malignant change within the thyroid gland were shown to correlate well with corresponding histopathologic findings.Conclusions.The ability of OCT to image thyroid tissue microarchitecture makes it a potentially powerful technology that can be used to assess the thyroid gland at a resolution greater than currently available clinical imaging modalities. © 2004 Wiley Periodicals, Inc. Head Neck 26: 425–434, 2004
Previous chemotherapy as a predictor of wound infections in nonmajor head and neck surgery: Results of a prospective study
Authors: Penel Nicolas , Fournier Charles , Lefebvre Danièle , Roussel‐Delvallez Micheline , Sarini Jérome , Kara Ahmed , Mallet Yann , Lefebvre Jean‐Louis 
Published: April 2004

AbstractBackground.The goal of this prospective study was to determine the incidence of wound infections (WI) after clean uncontaminated head and neck cancer procedures and after emergency tracheotomies.Methods.Two hundred twelve clean procedures without tracheotomy or opening of mucosa (neck dissections, large skin resections, thyroidectomies, parotid gland resections, and explorative cervicotomies) were studied at Oscar Lambret Cancer Center over a 24‐month period.Results.WI rate was 6.6% (14 of 212). In a univariate analysis, only one variable was significantly related to the likelihood of WI: previous anticancer chemotherapy. All but one patient who had had previous chemotherapy demonstrated WI (14 of 15).Conclusions.After previous chemotherapy, WI rate in clean uncontaminated head and neck surgery was as high as 90%. In this case, antibiotic prophylaxis should be evaluated. © 2004 Wiley Periodicals, Inc. Head Neck 26: 513–517, 2004
Accuracy of visual screening for cervical neoplasia: Results from an IARC multicentre study in India and Africa
Authors: Sankaranarayanan Rengaswamy , Basu Parthasarathy , Wesley Ramani S. , Mahe Cédric , Keita Namory , Mbalawa Charles C. Gombe , Sharma Rameshwar , Dolo Amadou , Shastri Surendra S. , Nacoulma Marius , Nayama Madi , Somanathan Thara , Lucas Eric , Muwonge Richard , Frappart Lucien , Parkin D. Maxwell ,   for the IARC Multicentre Study Group on Cervical Cancer Early Detection
Published: April 2004

AbstractVisual inspection‐based screening tests, such as visual inspection with 4% acetic acid (VIA) and with Lugol's iodine (VILI), have been proposed as alternatives to cytology in mass screening programs. To date, there is only limited information on the accuracy of these tests in detecting High‐grade Squamous Intraepithelial Lesions (HSIL). Eleven cross‐sectional studies involving 56,939 women aged 25–65 years were conducted in Burkina Faso, Congo, Guinea, India, Mali and Niger to evaluate the accuracy of VIA and VILI performed by health workers. A common protocol and questionnaire was used. For final diagnosis, all women were investigated with colposcopy and biopsies were taken when necessary. Data from the studies were pooled to calculate sensitivity, specificity and predictive values of the tests for the detection of HSIL. Of the screened women, 16.1% and 16.4% were positive on examination using, respectively, VIA and VILI; 1,063 were diagnosed with HSIL. The pooled sensitivity, specificity, positive and negative predictive values for VIA were 76.8% (95% CI: 74.2–79.4%), 85.5% (95% CI: 85.2–85.8%), 9.4% (95% CI:8.8–10.8%) and 99.5% (95% CI:99.4–99.6%), respectively. The values were 91.7% (95% CI: 89.7–93.4%), 85.4% (95% CI: 85.1–85.7%), 10.9% (95% CI: 10.2–11.6%) and 99.8% (95% CI:99.7–99.9%), respectively for VILI. The range of sensitivity and specificity for VIA was 56.1–93.9% and 74.2–93.8%, respectively, between studies and were 76.0–97.0 % and 73.0–91.3% for VILI. VILI had a significantly higher sensitivity than VIA in detecting HSIL, but specificity was similar. VILI appears to be a more accurate visual test for use in screening and treatment programs in low‐resource settings. © 2004 Wiley‐Liss, Inc.
Genetic evolution in colon cancer KM12 cells and metastatic derivates
Authors: Camps Jordi , Morales Cristina , Prat Esther , Ribas Maria , Capellà Gabriel , Egozcue Josep , Peinado Miguel A. , Miró Rosa 
Published: April 2004

AbstractSo far, CRC cell lines have contributed to descriptions of 2 patterns of genetic instability, affecting either microsatellite sequences or chromosome number and structure. Often, these patterns are mutually exclusive; while near‐diploid karyotypes usually appear with MSI and chromosomal stability, near‐triploid or tetraploid cells display a high degree of CIN and are stable at the microsatellite level. In the present study, we describe the genomic instability pattern of KM12 CRC cells. KM12C and derived cell lines with different metastatic properties were analyzed by conventional cytogenetics, CGH and M‐FISH. Results were compared to 5 cell lines usually used as model of MSI and CIN. Concordance between our results and previously published SKY data are also reviewed. Interestingly, the poorly metastatic KM12C cell line displayed a near‐diploid karyotype with high levels of structural chromosome instability and microsatellite instability. The highly metastatic KM12SM and KM12L4A cell lines showed polyploid karyotypes and maintained CIN and MSI. A comparison between karyotypes of poorly and highly metastatic KM12 cell lines allowed us to delineate a cytogenetic evolution pathway. Our results clearly demonstrated that endoreduplication was the origin of the polyploid dosages in the highly metastatic forms following the monosomic model postulated for CRC. Therefore, we demonstrate that KM12C cells and their metastatic derivates, KM12SM and KM12L4A, are a useful model of chromosomal evolution where MSI may coexist with CIN. © 2004 Wiley‐Liss, Inc.
Molecular classification of oral cancer by cDNA microarrays identifies overexpressed genes correlated with nodal metastasis
Authors: Warner Giles C. , Reis Patricia P. , Jurisica Igor , Sultan Mujahid , Arora Shilpi , Macmillan Christina , Makitie Antti A. , Grénman Reidar , Reid Nancy , Sukhai Mahadeo , Freeman Jeremy , Gullane Patrick , Irish Jonathan , Kamel‐Reid Suzanne 
Published: April 2004

AbstractOur purpose was to classify OSCCs based on their gene expression profiles, to identify differentially expressed genes in these cancers and to correlate genetic deregulation with clinical and histopathologic data and patient outcome. After conducting proof‐of‐principle experiments utilizing 6 HNSCC cell lines, the gene expression profiles of 20 OSCCs were determined using cDNA microarrays containing 19,200 sequences and the BTSVQ method of data analysis. We identified 2 sample clusters that correlated with the T3‐T4 category of disease (p = 0.035) and nodal metastasis (p = 0.035). BTSVQ analysis identified a subset of 23 differentially expressed genes with the lowest QE scores in the cluster containing more advanced‐stage tumors. Expression of 6 of these differentially expressed genes was validated by quantitative real‐time RT‐PCR. Statistical analysis of quantitative real‐time RT‐PCR data was performed and, after Bonferroni correction, CLDN1 overexpression was significantly correlated with the cluster containing more advanced‐stage tumors (p = 0.007). Despite the clinical heterogeneity of OSCC, molecular subtyping by cDNA microarray analysis identified distinct patterns of gene expression associated with relevant clinical parameters. Application of this methodology represents an advance in the classification of oral cavity tumors and may ultimately aid in the development of more tailored therapies for oral carcinoma. © 2004 Wiley‐Liss, Inc.
Monolayer versus aggregate balance in survival process for EGF‐induced apoptosis in A431 carcinoma cells: Implication of ROS‐P38 MAPK‐integrin α2β1 pathway
Authors: Morazzani Marie , de Carvalho Daniela Diogenes , Kovacic Herve , Smida‐Rezgui Sophia , Briand Claudette , Penel Claude 
Published: April 2004

AbstractA431 cells escape EGF‐induced apoptosis by forming cell aggregates. We show that these clusters migrate and merge with neighboring ones, resulting in larger structures composed of a multilayer central (3D) population surrounded by a cell monolayer (2D). We found that after 48 hr of 10 nM EGF treatment, 3D structure formation correlates with α2β1 integrin upregulation. Blockade of α2 integrin impairs 3D structure formation. We studied the involvement of reactive oxygen species (ROS) in this process. We show that A431 cells express the NADPH oxidase catalytic subunits Nox1. EGF‐induced dose‐dependant ROS production was inhibited by the NADPH oxidase inhibitor, diphenylene iodonium (DPI), in these cells while rotenone was ineffective. Inhibition of ROS level in A431 cells with DPI or ebselen (glutathione peroxydase mimic) as well as P38 MAP kinase inhibition by SB203580 decreases α2 integrin subunit expression and induces a shift to 3D versus 2D populations. Cell cycle analysis of 2D cells shows that DPI, ebselen and SB203580 decrease the number of cells in S/G2 phase without affecting the cell number in mitosis phase. On the contrary, for 3D cells, these treatments increased the proportion of cells in mitosis without modification of the cell number in S/G2 phase. For both populations, apoptosis was increased by DPI and ebselen. Resistance of cell aggregates by paclitaxel to cell death is usually described. We show that DPI abolishes paclitaxel resistance of 3D cell aggregates. We observed a greater than additive effect between paclitaxel and DPI resulting in an increased proportion of cells in S/G2 phase for 3D populations. These results suggested that the ROS‐P38 MAP kinase‐α2β1 integrin pathway was implicated in the A431 survival process by modulating the balance between 2D/3D cells. © 2004 Wiley‐Liss, Inc.
Vacuum ultraviolet treatment of polyethylene to change surface properties and characteristics of protein adsorption
Authors: Vasilets Viktor N. , Kuznetsov Artem V. , Sevastianov Viktor I. 
Published: April 2004

AbstractThe effects of vacuum ultraviolet (VUV) treatment on surface chemical composition morphology and albumin adsorption for low‐density polyethylene (LDPE) and high‐density polyethylene (HDPE) were investigated. The attenuated total reflection‐Fourier transform infrared (ATR‐FTIR) spectra and contact angle measurements indicated the formation of oxygen‐containing polar groups and double bonds under VUV photooxidation in the presence of air or under VUV irradiation in vacuum. Scanning electron microscopy revealed the development of regular structure with the period about 1 μm on the surface of LDPE and HDPE during VUV photooxidation. The correlation between amount of tightly adsorbed albumin and surface concentration of carboxyl groups generated by VUV irradiation was found. The aging effect for protein adsorption during long storage of VUV irradiated samples in air or phosphate‐buffered saline (PBS) was studied. The obtained results prove the VUV irradiation provides a high potential to regulate protein adsorption on polymers for biomedical applications. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 428–435, 2004