bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recreational Use of Sildenafil by HIV-Positive and -Negative Homosexual/Bisexual Males
Authors: Romanelli Frank , Smith Kelly M 
Published: May 2004

OBJECTIVE: To conduct an epidemiologic review of sildenafil in homosexual and bisexual males focusing on concurrent use with club drugs and/or antiretroviral medications. DATA SOURCES: A search of MEDLINE was conducted (1966–September 2003), and an extensive manual review of journals was performed using the key search terms club drugs, sildenafil, antiretrovirals, and HIV. STUDY SELECTION AND DATA EXTRACTION: All articles identified from the data sources were evaluated and information deemed relevant was included. DATA SYNTHESIS: Several epidemiologic studies have reported that sildenafil is abused in a recreational fashion, typically with agents commonly known to be “club drugs.” In this setting, sildenafil may reverse the impotence-inducing effects of the club drugs and restore sexual capabilities. Many implications of both recreational and nonrecreational use of sildenafil exist in relation to HIV disease. Concern has been raised regarding the potential effects on high-risk sexual practices. Also, several researchers have documented interactions between sildenafil and various club drugs, as well as with antiretrovirals intended for HIV disease. CONCLUSIONS: Serious concerns exist regarding the concurrent use of sildenafil with antiretrovirals and/or club drugs. Clinicians prescribing sildenafil to patients receiving protease inhibitor—containing antiretroviral regimens should be aware of the potential for reduced sildenafil metabolism with resultant adverse effects. Additionally, untoward effects may also occur when sildenafil is used concurrently with various club drugs including amyl and butyl nitrites (“poppers”).
Cost-Effectiveness of Escitalopram versus Citalopram in the Treatment of Severe Depression
Authors: Hemels Michiel EH , Kasper Siegfried , Walter Evelyn , Einarson Thomas R 
Published: May 2004

BACKGROUND: Severe depression is associated with an extensive economic burden on both the patient and society. OBJECTIVE: To estimate the cost-effectiveness in Austria of escitalopram compared with citalopram in the management of severe depression (Montgomery—Åsberg Depression Rating Scale score ≥30). METHODS: A decision model incorporated treatment paths and associated direct resource use (psychiatric hospitalization, medications, general practitioner and psychiatrist visits, treatment discontinuation, suicide attempts) associated with managing severe depression and the indirect cost of work absenteeism over a 6-month period. Main outcomes were clinical success (remission at 6 mo) and cost (2002 Euros equals ∼1.25 US) of treatment. The analysis was performed from the Austrian societal and Social Healthcare Insurance System (SHIS) perspectives. Clinical input data were derived from a meta-analysis of 8-week randomized clinical trials. Costs were derived from standard Austrian price lists or from the literature. RESULTS: Six months after the start of treatment, the overall clinical success remission rate was higher for escitalopram (53.7%) than for citalopram (48.7%). From the SHIS perspective, the total expected cost per successfully treated severely depressed patient was €924 (32.1%) lower for escitalopram (€2879) compared with citalopram (€3803). From the societal perspective, the total expected cost per successfully treated severely depressed patient was €1369 (24.4%) lower for escitalopram (€5610) than for citalopram (€6979). Sensitivity analyses demonstrated that the model was robust and that, even if citalopram had no acquisition cost, escitalopram remained the dominant strategy for both perspectives. CONCLUSIONS: Treatment with escitalopram was the dominant strategy. These data suggest that escitalopram is a cost-effective antidepressant compared with citalopram in the management of severe depression in Austria.
Simultaneous Determination of α-Fetoprotein and Free β-Human Chorionic Gonadotropin by Element-Tagged Immunoassay with Detection by Inductively Coupled Plasma Mass Spectrometry
Authors: Zhang Sichun , Zhang Chao , Xing Zhi , Zhang Xinrong 
Published: May 2004

AbstractBackground: An inductively coupled plasma mass spectrometry (ICP-MS)-based immunoassay has been proposed independently by Baranov et al. (Anal Chem 2002;74:1629–36) and our group, but the applicability of this method for multianalyte analysis in clinical samples has not been fully illustrated. We developed a dual-label immunoassay method for the simultaneous determination of α-fetoprotein (AFP) and free β-human chorionic gonadotropin (hCGβ) in human serum.Methods: Monoclonal antibodies immobilized on microtiter plates captured AFP and hCGβ, which were detected by use of Eu3+-labeled anti-AFP and Sm3+-labeled anti-hCGβ monoclonal antibodies. Eu3+ and Sm3+ were dissociated from the immunocomplex with HNO3 solution (10 mL/L) and delivered by peristaltic pump to the ICP mass spectrometer.Results: The measurable ranges of AFP and hCGβ were 4.6–500 and 5.0–170 μg/L, respectively, with detection limits of 1.2 and 1.7 μg/L (3 SD above mean of zero calibrator), respectively. The intraassay imprecision (CV) for AFP was 8.3%, 4.0%, and 2.7% at 16.3, 86, and 354 μg/L, respectively, and the interassay CV was 10%, 5.7%, and 3.5%. For hCGβ, the intraassay CV was 5.4%, 6.4%, and 3.1%, respectively, at 10.5, 45.2, and 105 μg/L, and the interassay CV was 7.2%, 8.0%, and 3.7%. Comparison with IRMAs for AFP and hCGβ yielded correlation coefficients (r2) of 0.97 and 0.95.Conclusions: Two proteins can be measured simultaneously by immunoassays using two rare earth elemental tags (Eu3+ and Sm3+) and ICP-MS detection. The multielement capability and the multiple potential elemental labels make ICP-MS attractive for multianalyte immunoassays. Implementation of ICP-MS-linked immunoassays may be relatively straightforward because the labeling and immunoreaction procedures have been well developed for clinical time-resolved immunofluorometric assays.
Ontogeny of the VATER kidney in a rat model
Authors: Temelcos Catherine , Hutson John M. 
Published: April 2004

AbstractBy exposing rat fetuses to adriamycin prenatally, a rat model of VATER association has been created. Absence of the fetal bladder is prominent and the kidneys show features of chronic obstruction with hydronephrosis/hydroureter, loss of parenchyma, fewer glomeruli, and less differentiation. The aim of this study was to elucidate this rat model, to determine exactly when the changes in the kidneys develop, hopefully thereby to expand our understanding of congenital obstructive uropathy. Timed‐pregnant Sprague‐Dawley rats were injected intraperitoneally with adriamycin on days 6–9 of gestation. The control group received saline. Fetuses were recovered on gestational days (GDs) 20, 19, 18, 17, 16, 15, 14, 12, and 10 (total, 120 control, 121 treated). Macroscopic features were determined. Serial sections were then taken and stained with hematoxylin and eosin. Comparisons were made under light microscopy. The metanephric kidney first became apparent at GD12. The development of the control and treated kidneys appeared similar till GD18. Beyond this day, the treated kidneys exhibited increasing degrees of distension of Bowman's capsule, ducts, and subsequently pelvis and ureter. There were fewer levels of glomeruli, which were also less differentiated. Less differentiation was also noted in the medulla, and with time this became thin in comparison to the control kidneys. By GD20, the renal pelvis was grossly dilated with a blunted papilla, and the renal parenchyma was thin. Prenatal exposure of rat fetuses to adriamycin results in kidneys that are chronically obstructed, as the majority of the fetuses show absence of the bladder. Absence of renal dysmorphology until GD18, when urine is first produced, suggests strongly that the effect of adriamycin on the kidney is indirect, via agenesis of the bladder and secondary to backpressure from early urine production. This is a unique, simple, and reliable model of fetal obstructive uropathy and will be very useful to facilitate further investigation into its pathophysiology and to explore new treatment options. Anat Rec Part A 278A:520–527, 2004. © 2004 Wiley‐Liss, Inc.
Ultrastructure of the osteocyte process and its pericellular matrix
Authors: You Li‐Dan , Weinbaum Sheldon , Cowin Stephen C. , Schaffler Mitchell B. 
Published: April 2004

AbstractOsteocytes are believed to be the mechanical sensor cells in bone. One potential physical mechanism for the mechanosensing process is that osteocytes directly sense the deformation of the substrate to which they are attached. However, there is a fundamental paradox in this theory: tissue‐level strains in whole bone are typically <0.2%, yet an extensive range of in vitro experiments show that dynamic substrate strains must be at least an order of magnitude larger in order for intracellular biochemical responses to occur. Recently, a theoretical model was developed (You et al. J. Biomech., 2001; 34:1375–1386) that provides a possible mechanism by which mechanical loading‐induced fluid flow in the lacuno‐canalicular system, under routine physical activity, can produce cellular‐level strains on the osteocyte processes that are at least one order of magnitude larger than bone tissue deformations. This would resolve the fundamental paradox mentioned above. In this work we experimentally confirm and quantify the essential ultrastructural elements in this model: 1) the presence of the transverse elements that bridge the pericellular space surrounding the osteocyte process, which interact with the fluid flow and lead to an outward hoop tension on the process; and 2) the presence of bundled F‐actin in the osteocyte processes, which resists the outward hoop tension and limits the cell process membrane deformation. Morphological data to support these assumptions are scant. Special staining techniques employing ruthenium III hexamine trichloride (RHT) were developed to elucidate these structures in the humeri of adult mice. Anat Rec Part A 278A:505–513, 2004. © 2004 Wiley‐Liss, Inc.
Modelling changes in volatility in the North Atlantic oscillation
Authors: Mills Terence C. 
Published: April 2004

AbstractThe NAO index constructed from 1659 by Luterbacher et al. (2002) is analysed using time series techniques designed to model long memory and volatility. The index is found to have a positively correlated short memory in mean and to exhibit long memory in conditional variance: the ‘volatility’ of the series. Copyright © 2004 Royal Meteorological Society
Metal‐ion‐ and pH‐induced conformational changes of acutolysin D from Agkistrodon acutus venom probed by fluorescent spectroscopy
Authors: Xu Xiao‐Long , Liu Xiang‐Hu , Wu Bin , Liu Yi , Liu Wen‐Qi , Xie Yong‐Shu , Liu Qing‐Liang 
Published: April 2004

AbstractAcutolysin D isolated from the venom of Agkistrodon acutus is a protein of 44 kDa with marked hemorrhagic and proteolytic activities. The metal‐ion‐ and pH‐induced conformational changes of acutolysin D have been studied by following fluorescence and activity measurements. Here we provide evidence for the fact that native holo‐acutolysin D adopts two different conformations, native state a, stable in the weak acidic pH range from 5.5 to 7.0 with low activity, and native state b, stable in the weak alkaline pH range from 8.0 to 9.0 with high activity. Holo‐acutolysin D has an optimum pH of 9.0 for caseinolytic activity and a maximum fluorescence at pH 9.0. The protein adopts the most stable conformation at pH 9.0. The addition of 1 mM Zn2+ shifts both the alkali‐induced unfolding transition curve and the alkali‐induced inactivation curve toward higher pH value but has little effect on the acid‐induced unfolding transition curve. No obvious effects on the pH‐induced unfolding transition curve and the pH‐dependent activity curve have been observed after the addition of 1 mM Ca2+ to holo‐acutolysin D. The results indicate that Zn2+ is essential for its CA, while Ca2+ is not essential for its CA. Removal of Ca2+ and Zn2+ from the protein enhances its sensitivity to pH and significantly reduces its overall stability during acid‐induced denaturation. The kinetic results of the demetalization of holo‐acutolysin D show that the demetalization rate constant K1 for a slower reaction linearly decreases with the pH increase from 5.0 to 9.0, while K2 for the faster reaction linearly increases with the pH change from 5.0 to 7.0. It is also evident from the present work that the free Zn2+‐induced inactivation in the pH range from 8.0 to 9.0 should be attributed to the effect of Zn(OH)2 precipitation on the protein. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
The schiff base of gossypol with 3,6,9,12,15,18,21,24‐octaoxa‐pentacosylamine complexes and monovalent cations studied by electrospray ionization–mass spectrometry, 1H nuclear magnetic resonance, Fourier transform infrared, as well as PM5 semiempirical methods
Authors: Przybylski Piotr , Brzezinski Bogumil , Bartl Franz 
Published: April 2004

AbstractA Schiff base of gossypol with 3,6,9,12,15,18,21,24‐octaoxa‐pentacosylamine (GSOB) forms stable complexes with monovalent cations. This process of complex formation was studied by electrospray ionization–mass spectrometry, 1H‐NMR and Fourier transform infrared spectroscopy as well as by the PM5 semiempirical method. It was found that GSOB forms 1:6 complexes with Li+ and Na+, and 1:4 complexes with K+ as well as 1:2 complexes with Rb+ or Cs+ cations and exists in all these complexes in the enamine–enamine tautomeric form. Moreover, within these complexes only Li+ cations can fluctuate between the oxygen atoms of the octaoxaalkyl chains. The interactions of Li+ cations with hydroxyl groups of the gossypol part is also possible. All other cations are much more localized. In the complex of GSOB with protons, a 1:2 stoichiometry is realized. The two protons are localized on the N atoms of the Schiff base, and the complex exists in the imine–imine tautomeric form. The structures of the complexes are calculated by PM5 semiempirical methods and discussed. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Structural studies of wheat flour glutenin polymers by CD spectroscopy
Authors: Fisichella S. , Amato M. E. , Lafiandra D. , Mantarro D. , Palermo A. , Savarino A. , Scarlata G. 
Published: April 2004

AbstractA dissolution procedure of unreduced glutenin polymers of three wheat flour varieties (WRU 6981, Alisei 1, and Alisei 2) by sonication in the presence of SDS (sodium dodecyl sulphate), after the elimination of albumins, globulins, and gliadins, was achieved, and the molecular weight distribution of glutenin polymers obtained by this method was measured by matrix assisted laser desorption ionization–time of flight (MALDI‐TOF) mass spectrometry. A structural study by CD spectroscopy at different temperatures of WRU 6981 glutenin polymer and of 1Ax1 high‐Mr (relative molecular mass) glutenin subunit, which is the only high‐Mr subunit contained in WRU 6981 flour, was undertaken to understand if the information obtained from the single subunit were applicable to the total polymer. CD spectroscopy also has been employed to study the glutenin polymers obtained by Alisei 1 and Alisei 2 wheat flours; Alisei 1 biotype contained 1Bx7 and 1Dx2+1Dy12 high‐Mr subunits, whereas the Alisei 2 biotype contained only 1Bx7 and 1Dy12 subunits. A conformational study was undertaken by CD spectroscopy at different temperatures and in the presence of some chemical denaturant agents, such as urea and sodium dodecyl sulphate, in order to obtain information about their intrinsic stability and to verify if the 1Dx2 subunit presence determined a different structural behavior between Alisei 1 and Alisei 2 polymers. MALDI‐TOF mass spectrometric experiments showed that the glutenin polymers molecular weights were in the mass range of 500,000–5,000,000. CD spectra indicated that a single conformational state did not predominate in the temperature range studied but equilibrium between two distinct conformational states existed; moreover, all the changes induced by urea and by SDS followed a multistep transition process. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Structural evolution of regenerated silk fibroin under shear: Combined wide‐ and small‐angle x‐ray scattering experiments using synchrotron radiation
Authors: Rössle Manfred , Panine Pierre , Urban Volker S. , Riekel Christian 
Published: April 2004

AbstractThe structural evolution of regenerated Bombyx mori silk fibroin during shearing with a Couette cell has been studied in situ by synchrotron radiation small‐ and wide‐angle x‐ray scattering techniques. An elongation of fibroin molecules was observed with increasing shear rate, followed by an aggregation phase. The aggregates were found to be amorphous with β‐conformation according to infrared spectroscopy. Scanning x‐ray microdiffraction with a 5 μm beam on aggregated material, which had solidified in air, showed silk II reflections and a material with equatorial reflections close to the silk I structure reflections, but with strong differences in reflection intensities. This silk I type material shows up to two low‐angle peaks suggesting the presence of water molecules that might be intercalated between hydrogen‐bonded sheets. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
A mixed finite element solver for liquid–liquid impacts
Authors: Bertolazzi Enrico , Manzini Gianmarco 
Published: April 2004

AbstractThe impact of a liquid column on a liquid surface initially at rest is numerically modelled to describe air entrapment and bubble formation processes. The global quantities of interest are evaluated in the framework of the potential theory. The numerical method couples a potential flow solver based on a Mixed Finite Element Method with an Ordinary Differential Equation solver discretized by the Crank–Nicholson scheme. The capability of the method in solving liquid–liquid impacts is illustrated in two numerical experiments taken from literature and a good agreement with the literature data is obtained. Copyright © 2004 John Wiley & Sons, Ltd.
Remarks on numerical prediction of wall shear stress in entry flow problems
Authors: Darbandi M. , Hosseinizadeh S. F. 
Published: April 2004

AbstractToday, commercial CFD codes are widely used to simulate many different entry flow problems. The flow in the developing zone undergoes a transition from a specified velocity profile at the inlet section to a fully developed profile in the region far from the inlet. Previous investigations have shown that the hydrodynamic variables, such as velocity and pressure magnitudes, along the centreline converge to a mesh independent solution even when coarse grid distributions are utilised. However, the present work shows that the local velocity profile is highly dependent on grid resolution in the vicinity of solid boundaries. It is shown that failure to account for the grid resolution can result in significant errors in the predicted solid–fluid interaction, e.g. wall shear stress calculation. A remedy to overcome this problem is subsequently given. Copyright © 2004 John Wiley & Sons, Ltd.
Transonic shock in a nozzle I: 2D case
Authors: Xin Zhouping , Yin Huicheng 
Published: April 2004

AbstractIn this paper we establish the existence and uniqueness of a transonic shock for the steady flow through a general two‐dimensional nozzle with variable sections. The flow is governed by the inviscid potential equation, and is supersonic upstream, has no‐flow boundary conditions on the nozzle walls, and a given pressure at the exit of the exhaust section. The transonic shock is a free boundary dividing two regions of C flow in the nozzle. The potential equation is hyperbolic upstream where the flow is supersonic, and elliptic in the downstream subsonic region. In particular, our results show that there exists a solution to the corresponding free boundary problem such that the equation is always subsonic in the downstream region of the nozzle when the pressure in the exit of the exhaustion section is appropriately larger than that in the entry. This confirms exactly the conjecture of Courant and Friedrichs on the transonic phenomena in a nozzle [10]. Furthermore, the stability of the transonic shock is also proved when the upstream supersonic flow is a small steady perturbation for the uniform supersonic flow or the pressure at the exit has a small perturbation. The main ingredients of our analysis are a generalized hodograph transformation and multiplier methods for elliptic equation with mixed boundary conditions and corner singularities. © 2004 Wiley Periodicals, Inc.
Technical basis on structural fire resistance design in building standards law of Japan
Authors: Harada Kazunori , Ohmiya Yoshifumi , Natori Akiko , Nakamichi Akiko 
Published: April 2004

AbstractStructural fire resistance design method came into effect due to the revision of Japan's building code (building standards law of Japan) in June 2001. The method includes standard methods to calculate (1) fire exposure to structural elements, (2) temperature rise of steel and RC elements during fire exposure and (3) structural end points such as ultimate steel temperature for buckling of columns, bending failure of beams and so on. This paper discusses the technical basis for design methods especially focused on steel framed buildings. The calculated values by design equations were compared with experimental values in order to examine the redundancies implied. In the final stage, all the redundancies were combined by Monte‐Carlo method and first‐order moment method (AFORM). Target safety index and corresponding partial safety factors were discussed. Copyright © 2004 John Wiley & Sons, Ltd.
The Characteristics of a PEM Fuel Cell Engine with 40 kW Vehicle Stacks
Authors: Hou M. , Ming P. , Sun D. , Liu Y. , Hui X. , Zhang H. , Yi B. 
Published: April 2004

AbstractThis paper describes a PEM Fuel Cell Engine (FCE) with 40 kW stacks designed for a car. This was developed by DICP and Sunrise Power and is funded by the Chinese “863” key project. The FCE system construction, stack performance, specifications, and operating characteristics are explained. The efficiency of the FCE is analyzed. The net power output for this FCE is 27 kW and the efficiency is 35–38%. The utilization of air and hydrogen are more than 50% and 97%, respectively.
Improving communication between health and infant mental health professionals utilizing ongoing Collaborative Peer Supervision Groups
Authors: Thomasgard Michael , Warfield Janeece , Williams Rosalind 
Published: April 2004

AbstractThis article discusses the use of Collaborative Peer Supervision Groups (CPSG) to promote ongoing professional development for those who work with infants, toddlers, and their families. Our model's strength and clinical utility result from its three major components: (a) a relationship‐based perspective that acknowledges the important role that feelings and emotions play across the life span, (b) a peer supervision model that helps to ensure that no individual or discipline is “the expert,” and (c) a collaborative case‐based continuing‐education experience. Salient features of forming and maintaining a CPSG group are discussed including access to a Web site containing many key start‐up and evaluation materials. Existing barriers to effective communication between disciplines are discussed as are specific methods to structure case data. Additional tools to help anchor a CPSG are considered as are methods of evaluation. Two case presentations are considered to illustrate group process. Lessons learned from such groups are highlighted. Our intent is to provide sufficient background material so that others with a similar interest will be comfortable starting and maintaining a CPSG group on their own. ©2004 Michigan Association for Infant Mental Health.