bluuebunny/crossref_metadata_2025_split huggingface dataset:
A review of vaccines for HIV prevention
Authors: Mwau Matilu , McMichael Andrew J. 
Published: January 2003

AbstractHIV/AIDS has become the most devastating pandemic in recorded history. It has killed 40 million people in the last 20 years and the World Health Organisation estimated that at least 14 000 new infections occurred daily in 2001. There will be up to 100 million new infections in the next 10 years (for current updates, visit http://www.unaids.org/epidemic_update/).Most HIV infections occur in the developing world, and the adverse social and economic impact of the HIV/AIDS pandemic, particularly in the developing world, is unprecedented.Highly active antiretroviral therapy (HAART) has had significant effects on HIV/AIDS in the developed world. The drugs have acted to prolong survival, reduce the viral load, and to alleviate suffering. However, the incidence of side effects and resistance is high and the drugs are unaffordable and unavailable in the developing world. HAART regimens are difficult to comply with. Public health efforts to modify the behaviour, attitude and culture that accelerate the spread of HIV/AIDS have had only modest success.There is urgent need for a prophylactic and/or therapeutic HIV vaccine. This is a review of the obstacles and current trends in HIV vaccine development. Copyright © 2002 John Wiley & Sons, Ltd.
Hot‐electron numerical modelling of short gate length pHEMTs applied to novel field plate structures
Authors: Hussain Shahzad , Cole Eric A. B. , Snowden Christopher M. 
Published: January 2003

AbstractHot‐electron numerical simulations were carried out in order to simulate the DC parameters of pseudomorphic high electron mobility transistors (pHEMTs). The hot‐electron effects were studied by simulating several HEMT device structures. Hot‐carrier injection in the substrate and the formation of the peak of electric field in the channel were studied in detail. The inclusion of a field‐plate contact in a multiple recessed pHEMT structure lowered the peak value of the electric field by 24% compared with the conventional pHEMT. These devices were modelled by solving the two‐dimensional Poisson, current continuity and energy transport equations consistently with the time‐independent Schrödinger wave equation. Appropriate Ohmic boundaries are discussed here and implemented in the simulations of pHEMT structures. A new integral approximation is used to calculate electron densities and electron energy densities for degenerate approximations. Copyright © 2002 John Wiley & Sons, Ltd.
Influence of the carrier diffusion process on the transient response of vertical‐cavity surface‐emitting lasers
Authors: Torre M. S. , Ranea‐Sandoval H. F. 
Published: January 2003

AbstractWe investigate the transverse mode dynamics of weakly index‐guided vertical‐cavity surface‐emitting lasers (VCSEL). The turn‐on time of transverse modes are calculated by implementing a model for the VCSEL dynamics including diffusion and transport/capture phenomena. It takes into account the spatial dependence of the two carrier density profiles associated with the confined carriers in the quantum wells, and with the unconfined carriers in the barrier region. Devices of different aperture diameter under different excitation conditions are also studied. The model displays the correct turn‐on time dependence on the injection current density when compared with the experimental data available. We show that the turn‐on time of the modes increases when capture time increases and escape time decreases and also when diffusion increases. Copyright © 2002 John Wiley & Sons, Ltd.
A parallel 3D semiconductor device simulator for gradual heterojunction bipolar transistors
Authors: J. García‐Loureiro Antonio , López‐González J. M. , F. Pena Tomás 
Published: January 2003

AbstractIn this paper, we present a parallel three‐dimensional semiconductor device simulator for gradual heterojunction bipolar transistor. This simulator uses the drift‐diffusion transport model. The Poisson equation and continuity equations were discretized using a finite element method (FEM) on an unstructured tetrahedral mesh. Fermi–Dirac statistics is considered in our model and a compact formulation is used that makes it easy to take into account other effects such as the non‐parabolic nature of the bands or the presence of various subbands in the conduction process. Domain decomposition methods were tested to solve the linear systems. We have applied this simulator to a gradual heterojunction bipolar transistor (HBT), and we present some measures of the parallel execution time for several solvers and some electrical results. This code has been implemented for distributed memory multicomputers, making use of the MPI message passing standard library and a parallel solver library. Copyright © 2002 John Wiley & Sons, Ltd.
An agent‐based framework for parametric studies of numerical modelling problems in computational electromagnetics
Authors: Biniaris C. G. , Kostaridis A. I. , Kaklamani D. I. , Venieris I. S. 
Published: January 2003

AbstractIn this paper, we present the design of a generic agent‐based framework for distributed parametric analysis of numerical modelling problems on a network of workstations and its application in computational electromagnetics (CEM). The entire infrastructure is based on a Master–Worker paradigm that utilizes mobile agents in order to gather information about the hosts of the network, transfer the native code there, handle its execution and collect the results. Such a framework enables scientists and engineers to perform simulations and parametric studies, in order to determine configurations and characteristics of the scenarios being modelled and, thereby, to greatly improve and shorten design processes. A case study in antenna modelling is presented, in order to test the efficiency of the developed framework. Copyright © 2002 John Wiley & Sons, Ltd.
Verification of 1D BJT numerical simulation and its application to mixed‐level device and circuit simulation
Authors: Chang Chia‐Cherng , Dai Jing‐Fu , Tsai Yao‐Tsung 
Published: January 2003

AbstractIn this paper, we study on a 1D BJT model, which saves the memory size and computation time and verify that the characteristic of 1D BJT model is in good agreement with 2D BJT model. We use the equivalent circuit approach to simulate the BJT device. Poisson's equation and continuity equations for electron and hole are formulated into a subcircuit format suitable for general circuit simulator in the equivalent circuit approach. In order to solve the 2D device simulation, the simulation environment needs a powerful solver. So we use the band matrix solver to replace the full matrix solver. But the 2D BJT simulation still needs a large computation time, so we must develop the efficient 1D BJT model. In 1D BJT simulation, we have overcome the base boundary condition and verified that the base boundary conditions in 1D BJT model closely approach to that in 2D BJT model. Finally, we apply it to two applications and study the operation concepts of these applications. Copyright © 2002 John Wiley & Sons, Ltd.
Experimental photodynamic therapy for malignant pleural mesothelioma with pegylated mTHPC
Authors: Krueger Thorsten , Altermatt Hans J. , Mettler Daniel , Scholl Beatrix , Magnusson Lennart , Ris Hans‐Beat 
Published: January 2003

AbstractBackground and ObjectivesExperimental assessment of photodynamic therapy (PDT) for malignant pleural mesothelioma using a polyethylene glycol conjugate of meta‐tetrahydroxyphenylchlorin (PEG–mTHPC).Study Design/Materials and Methods(a) PDT was tested on H‐meso‐1 xenografts (652 nm laser light; fluence 10 J/cm2; 0.93, 9.3, or 27.8 mg/kg of PEG–mTHPC; drug‐light intervals 3–8 days). (b) Intraoperative PDT with similar treatment conditions was performed in the chest cavity of minipigs (n = 18) following extrapleural pneumonectomy (EPP) using an optical integrating balloon device combined with in situ light dosimetry.Results(a) PDT using PEG–mTHPC resulted in larger extent of tumor necrosis than in untreated tumors (P ≤ 0.01) without causing damage to normal tissue. (b) Intraoperative PDT following EPP was well tolerated in 17 of 18 animals. Mean fluence and fluence rates measured at four sites of the chest cavity ranged from 10.2 ± 0.2 to 13.2 ± 2.3 J/cm2 and 5.5 ± 1.2 to 7.9 ± 1.7 mW/cm2 (mean ± SD). Histology 3 months after light delivery revealed no PDT related tissue injury in all but one animal.ConclusionsPEG–mTHPC mediated PDT showed selective destruction of mesothelioma xenografts without causing damage to intrathoracic organs in pigs at similar treatment conditions. The light delivery system afforded regular light distribution to different parts of the chest cavity. Lasers Surg. Med. 32:61–68,2003. © 2003 Wiley‐Liss, Inc.
MRI thermodosimetry in laser‐induced interstitial thermotherapy
Authors: Prudhomme Michel , Mattéi‐Gazagnes Martine , Fabbro‐Peray Pascale , Puche Pierre , Chabalier Jean‐Paul , Delacrétaz G. , François‐Michel Lopez F.M. , Godlewski Guilhem 
Published: January 2003

AbstractBackground and ObjectivesThe aim of this study was to establish a correlation between a thermal measurement and a magnetic resonance imaging (MRI) signal during laser‐induced interstitial thermotherapy (LITT) in liver.Study Design/Materials and MethodsPig liver was irradiated for 15 minutes with a diode laser at two different powers, 0.5 W (450 J) and 1.5 W (1,350 J). Tissue temperature was monitored every 20 seconds using thermocouples. Thermosensitive MRI sequences (T1‐weighted Turbo‐Flash) were acquired with the same irradiation parameters. Correlation between MRI signals (SI) and temperature measures was defined at two different distances from the fiber (5 and 10 mm).ResultsAt 0.5 W, temperatures rose progressively up to a maximum increase of 9.5°C at 5 mm and 4°C at 10 mm after 15 minutes. The corresponding MRI signal decreased progressively to −27.6 SI at 5 mm and −18.5 SI at 10 mm. At 1.5 W, temperatures rose dramatically at 5 mm, reaching a plateau. The temperature elevation measured at the end of the irradiation was of 30°C whereas at 10 mm it was only 14.5°C. The MRI signal varied accordingly, remaining inversely proportional to temperature (−76 SI at 5 mm and −35.5 SI at 10 mm).ConclusionsAn inversely proportional relationship was observed between MRI signal in sequential Turbo‐Flash and temperature. MRI should allow to analyze heat diffusion in the liver, and thus to monitor real‐time LITT treatments. Lasers Surg. Med. 32:54–60,2003. © 2003 Wiley‐Liss, Inc.
Temporally and spectrally resolved fluorescence spectroscopy for the detection of high grade dysplasia in Barrett's esophagus
Authors: Pfefer T. Joshua , Paithankar Dilip Y. , Poneros John M. , Schomacker Kevin T. , Nishioka Norman S. 
Published: January 2003

AbstractBackground and ObjectivesTemporal and spectral fluorescence spectroscopy can identify adenomatous colonic polyps accurately. In this study, these techniques were examined as a potential means of improving the surveillance of high grade dysplasia (HGD) in Barrett's esophagus (BE).Study Design/Materials and MethodsUsing excitation wavelengths of 337 and 400 nm, 148 fluorescence spectra, and 108 transient decay profiles (at 550 ± 20 nm) were obtained endoscopically in 37 patients. Corresponding biopsies were collected and classified as carcinoma, HGD, or low risk tissue (LRT) [non‐dysplastic BE, indefinite for dysplasia (IFD), and low grade dysplasia (LGD)]. Diagnostic algorithms were developed retrospectively using linear discriminant analysis (LDA) to separate LRT from HGD.ResultsLDA produced diagnostic algorithms based solely on spectral data. Moderate levels of sensitivity (Se) and specificity (Sp) were obtained for both 337 nm (Se = 74%, Sp = 67%) and 400 nm (Se = 74%, Sp = 85%) excitation.ConclusionsIn the diagnosis of HGD in BE, steady‐state fluorescence was more effective than time‐resolved data, and excitation at 400 nm excitation was more effective than 337 nm. While fluorescence‐targeted biopsy is approaching clinical usefulness, increased sensitivity to dysplastic changes—possibly through modification of system parameters—is needed to improve accuracy levels. Lasers Surg. Med. 32:10–16,2003. © 2003 Wiley‐Liss, Inc.
Prospective study on the treatment of postburn hyperpigmentation by intense pulsed light
Authors: Ho Wai Sun , Chan Henry H. , Ying Shun Yuen , Chan Pik Chu , Burd Andrew , King Walter WK. 
Published: January 2003

AbstractBackground and ObjectivesPostburn hyperpigmentation is a common phenomenon among Asian especially over grafted areas and sometimes over donor sites and healed wounds without skin graft. This condition is difficult to treat and can cause severe psychological distress. Intense pulsed light (IPL) has been used to treat melanocytic lesions with promising result. The role of IPL in treating postburn hyperpigmentation has not been explored. The purpose of this study was to assess the efficacy and complication of IPL in the treatment of postburn hyperpigmentation prospectively.Study Design/Materials and MethodsNineteen Chinese patients with postburn hyperpigmentation were treated by IPL. There were 14 females and 5 males. Their age ranged from 8 to 51 years with a mean age of 29.4 ± 11.6 years. The cutoff filters of 550, 570, and 590 nm were used for 3–7 treatments at intervals of 3–4 weeks. Patients were treated with an energy fluence of 28–46 J/cm2, pulse width of 1.7–4 milliseconds, double pulse mode, and a delay of 15–40 milliseconds.ResultsTreatment results and complications were evaluated and scored after each treatment. Over 78% of the patients showed more than 50% clinical clearance and nearly 32% of the patients were able to achieve more than 75% clearing. Although two patients had no clinical response, one patient had 100% clearing. Three patients developed blisters and one patient had erythema that all resolved within 1 week without leaving permanent marks. They have been followed‐up from 11–32 months and there was no recurrence of the hyperpigmentation.ConclusionsIPL is effective and safe in treating postburn hyperpigmentation in Asian patients. Lasers Surg. Med. 32:42–45,2003. © 2003 Wiley‐Liss, Inc.
Chronic and acute analysis of optic nerve sheath fenestration with the free electron laser in monkeys
Authors: Joos Karen M. , Mawn Louise A. , Shen Jin H. , Casagrande Vivien A. 
Published: January 2003

AbstractBackground and ObjectivesThe Amide II wavelength (6.45 μm) produced by the free electron laser (FEL) can efficiently create an optic nerve sheath fenestration in rabbits. We wished to determine if it would be equally successful in macaque monkeys and to determine the histopathologic changes between traditional scissors or knife optic nerve sheath fenestration to FEL fenestration.Study Design/Materials and MethodsOptic nerve sheath fenestration was performed using either the FEL (6.45 μm, 30 Hz, 2–3 mJ, 325‐μm spot size) through a hollow waveguide probe in 12 eyes or with a scissors or a knife in 6 eyes. The monkeys survived 1 month with the fellow optic nerve operated acutely just prior to sacrifice. Optic nerves were evaluated histologically.ResultsLess tissue manipulation was required using the FEL surgical probe. Electroretinograms showed minimal or no change. Tissue responses using either method were similar following chronic or acute incisions. Mild upregulation of vimentin and glial fibrillary acid protein (GFAP) was seen in astrocytes adjacent to the fenestration, but no change in S100β was evident.ConclusionsThe FEL energy at 6.45 μm delivered through a hollow waveguide appears capable of efficiently and safely producing an optic nerve sheath fenestration in monkeys. This innovative surgical technique should be considered for human use. Lasers Surg. Med. 32:32–41,2003. © 2003 Wiley‐Liss, Inc.
The influence of cytokines, chemokines and their receptors on HIV‐1 replication in monocytes and macrophages
Authors: Kedzierska Katherine , Crowe Suzanne M. , Turville Stuart , Cunningham Anthony L. 
Published: January 2003

AbstractMonocytes, macrophages and dendritic cells play an important role in the initial infection and contribute to its pathogenesis throughout the course of infection. Myeloid cells express CD4 and chemokine receptors known for HIV‐1 fusion and entry. The β‐chemokine receptor, CCR5, is the major co‐receptor in conjunction with CD4 for macrophage (M)‐tropic or (R5) isolates of HIV‐1, whereas the α‐chemokine receptor, CXCR4, facilitates entry of T‐tropic or (X4) HIV‐1 strains. Cells of myeloid lineage may be infected predominantly with R5‐ strains, although infection with dual‐tropic isolates of HIV‐1 (exhibiting the capacity to use CCR‐5 and/or CXCR‐4 for entry) or some strains of X4‐ isolates has also been reported. The expression of chemokine receptors, HIV‐1 infectio n and replication is under continuous regulation by a complex cytokine network produced by a variety of cells. The effects of cytokines/chemokines on HIV‐1 replication in cells of myeloid lineage can be inhibitory (IFN‐α, IFN‐β, IFN‐γ, GM‐CSF, IL‐10, IL‐13 and IL‐16 and β‐chemok ines), stimulatory (M‐CSF, TNF‐α, TNF‐β, IL‐1, IL‐6) or bifunction al, that is both inhibitory and stimulatory (IL‐4). This review focuses on the overall expression of chemokine receptors on cells of myeloid lineage and considers the mechanisms of entry of R5‐, X4‐ and dual‐tropic strains of HIV‐1 into these cells. The effects of cytokines/chemokines on viral entry and productive HIV‐1 infection are also reviewed. Copyright © 2003 John Wiley & Sons, Ltd.
Clinical consequences of hepatitis C virus infection
Authors: Zoulim F. , Chevallier M. , Maynard M. , Trepo C. 
Published: January 2003

AbstractHepatitis C virus (HCV) is a positive strand RNA virus that belongs to the Hepacivirinae genus within the Flaviviridae family. HCV infection has a wide spectrum of cellular tropism and clinical presentations. This has major impacts in terms of pathogenesis and diagnosis. Consequently, a wide range of clinical consequences characterises this viral infection, including asymptomatic chronic carriage, acute hepatitis, chronic hepatitis, cirrhosis, hepatocellular carcinoma and extrahepatic manifestations. The latter are commonly observed and may represent the first sign of the disease. A better knowledge of the pathobiology of HCV and its clinical consequences will be important for developing better treatment strategies to cure HCV infection and extrahepatic manifestations. Copyright © 2003 John Wiley & Sons, Ltd.
The new cell culture smallpox vaccine should be offered to the general population
Authors: Bicknell William , James Kenneth 
Published: January 2003

AbstractA series of major factors must be weighed in deciding whether or not, and to what extent, a particular country should consider pre‐exposure vaccination for smallpox. These include the risk of a bioterrorist attack using smallpox, the risk of secondary spread from another country, the risks and benefits of vaccination, the effectivenes s of vaccination pre‐ and post‐exposure, the prevalence of immunocompromised persons, the capacity of the medical care delivery system and the wealth of a nation. We review here the issues and variables relevant for policy making, propose a framework for country‐specific decision making and suggest the World Health Organization has a key role to play, particularly with regard to lower‐income countries. In doing so, we support the proposition. Copyright © 2003 John Wiley & Sons, Ltd.
The new cell culture smallpox vaccine should not be offered to the general population
Authors: Mortimer Philip P. 
Published: January 2003

AbstractCell based smallpox vaccines are to be welcomed, but any decision to vaccinate whole populations must await firstly better intelligence about the gravity of the threat from bioterrorists, including their ability to release smallpox in such a way that wide dissemination could take place; secondly evidence that vaccines grown in cell culture are protective and safe; and thirdly that the vaccines would be generally acceptable and their introduction would not compromise the rest of national immunisation programmes. Smallpox vaccination should not be offered to the general population until these uncertainties have been resolved, by which time bioterrorism might possibly have been overcome or the development of antiviral treatment might have made renewed smallpox vaccination unnecessary. Meanwhile, preparations for rapid deployment of the historically well‐tried containment measures at the epicentres of any smallpox release should proceed, their effectiveness should be tested, and their adequacy kept under review. Copyright © 2003 John Wiley & Sons, Ltd.
Solving problems: young children exploring the rules of the game
Authors: Hope Gill 
Published: January 2003

ABSTRACTThis article is not a review of the problem‐solving literature but instead explores the idea of children developing problem‐solving tactics as learning to applying the ‘rules of the game’, based on Wittgenstein's concept of ‘language games’. The kind of learning under discussion here is not learning of facts. I will not be discussing how we learn to recite the two times table but, rather, the dawning of understanding of what those facts mean: when a child realizes that the two times table divides up the whole universe into sets of either odds or evens. The necessity of accepting the rules of the game in order to perceive relevancy in determining problem‐solutions was illustrated by Donaldson's (1992) work with small children. The existence of general rules, and hence generic problem‐solving skills, is discussed and a model for problem‐solving is suggested. The article concludes with some observations on the role of rule‐breaking in discovery and invention. Examples are taken from the author's observations of young children in English classrooms.
Identity and the environment
Authors: Jones Verity 
Published: January 2003

ABSTRACTTeaching the origins and development of a common heritage in a multicultural society is a challenge for all teachers throughout the UK. What this article offers is an opportunity for teachers to think through links between the curriculum and issues of citizenship, encouraging children to develop a multi‐sited and multicultural identity. Visiting a botanical garden and discussing how children labelled themselves and others gives an example of how this can be put into practice in the classroom.