bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electromigration and charge carrier density versus free lattice volume effects in doped zirconia ceramics
Authors: M'Peko Jean‐Claude , Paz Fernando Y. , Mir Mirta , De Souza Milton F. 
Published: October 2004

AbstractIon conducting yttria‐stabilized tetragonal zirconia (3YTZ) and Er3+‐, Nd3+‐ and Hf4+‐doped 3YTZ ceramics were prepared and studied in this work. It is noted that dopant‐induced structural effects, associated with free lattice volume for bulk conduction, may still be dominant over charge carrier density effects, even for variations of these latter by up to about 30%. In that way, dopant ion size‐modified charge (oxygen vacancy) mobility varied to about +25% in Er3+‐doped 3YTZ and about –45% in Nd3+‐doped 3YTZ, with respect to original 3YTZ. Meanwhile, the behavior of grain‐boundary electrical properties appeared to adapt well with Frenkel's space‐charge model. In both bulk and grain‐boundary cases, the electrical response of Hf4+‐doped 3YTZ remained close to that from 3YTZ, a fact which is also discussed in this report. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dislocation scattering in a two‐dimensional electron gas of an AlxGa1−xN/GaN heterostructure
Authors: Han Xiuxun , Li Dabing , Yuan Hairong , Sun Xuehao , Liu Xianglin , Wang Xiaohui , Zhu Qinsheng , Wang Zhanguo 
Published: October 2004

AbstractThe theoretical electron mobility limited by dislocation scattering of a two‐dimensional electron gas confined near the interface of an AlxGa1−xN/GaN heterostructure is calculated. The accurate wave functions and electron distributions of the three lowest subbands for a typical structure are obtained by solving the Schrödinger and Poisson equations self‐consistently. Based on the model of treating dislocation as a charged line, a simple scattering potential, a square‐well potential, is utilized. The estimated mobility suggests that such a choice can simplify the calculation without introducing significant deviation from experimental data. It is also found that the dislocation scattering dominates both the low‐ and moderate‐temperature mobilities and accounts for the nearly flattening‐out behavior with increasing temperature. To clarify the role of dislocation scattering all standard scattering mechanisms are included in the calculation. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electric field effect on the binding energy of a non‐hydrogenic donor impurity in a cylindrical cross‐sectional quantum well wire
Authors: Ulaş M. , Cicek E. , Senturk Dalgic S. 
Published: October 2004

AbstractThe effect of an electric field on the non‐hydrogenic binding energy of a shallow donor impurity in a cylindrical cross‐sectional GaAs‐(Ga,Al)As quantum well wire (QWW) was investigated. Within the effective mass approximation, the non‐hydrogenic binding energy of the donor impurity was calculated by a variational method as a function of the wire radius, donor impurity position and applied electric field. The results show that the non‐hydrogenic binding energy of the donor impurity located around the centre is larger than that of the hydrogenic binding energy. The difference in binding energy of an on‐centre shallow donor impurity in the two regimes increases more rapidly with decreasing QWW radius than for other impurity positions. It has been found that the sensitivity of the donor binding energies to the applied electric field in both regimes is almost the same. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase transformation in CeGa2 under high pressure
Authors: Chandra Shekar> N. V. , Subramanian N. , Sanjay Kumar N. R. , Sahu P. Ch. 
Published: October 2004

AbstractWe have investigated the structural stability of the rare earth intermetallic compound cerium di‐gallide (CeGa2) under high pressure up to 32 GPa by performing X‐ray powder diffraction in a diamond anvil cell. CeGa2 exhibits a hexagonal AlB2 type structure at standard temperature and pressure (STP) (S.G. P6/mmm). On the application of pressure the hexagonal structure remains stable up to ∼16 GPa and subsequently a new phase emerges and coexists up to the maximum pressure studied. The high‐pressure phase is identified as a hexagonal crystal system with lower c/a ratio. The compressibility and its pressure derivative also have been calculated and reported. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of impurities in pesticides and their degradation products formed during the wine‐making process by solid‐phase extraction and gas chromatography with detection by electron ionization mass spectrometry. II. Bromopropylate, trichlorphon, parathion‐methyl and tebuconazole
Authors: Jiménez Juan José , Bernal José Luis , del Nozal M. Jesús , Toribio Laura , Bernal José 
Published: October 2004

AbstractThe presence of degradation products of bromopropylate, trichlorphon, parathion‐methyl and tebuconazole in white and red wines elaborated from musts spiked with commercial formulations of the pesticides was studied. Must and wine were subjected to solid‐phase extraction followed by gas chromatography with electron ionization mass spectrometric detection. α‐Bromophenylphenylmethanol, aminoparathion, acetylaminoparathion‐oxon and dichlorvos have been identified as degradation products of bromopropylate, parathion‐methyl and trichlorphon in wines, respectively. Moreover, the presence of additives and impurities of the formulations in elaborated wines has also been found. Copyright © 2004 John Wiley & Sons, Ltd.
Quantitative determination of ochratoxin A in kidneys by liquid chromatography/mass spectrometry
Authors: De Saeger S. , Dumoulin F. , Van Peteghem C. 
Published: October 2004

AbstractA sensitive liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) method for the quantitative determination of ochratoxin A (OTA) in kidney samples was developed. Ochratoxin B (OTB) was used as internal standard. Extraction of homogenized kidney samples was done by adding a chloroform/phosphoric acid mixture. Due to restriction of the sample size, less chloroform could be used than in previously described methods. Two different columns for clean‐up were compared: strong anion exchange (Bond Elut® SAX) and Extrelut® NT columns. The high‐performance liquid chromatography (HPLC) was used with gradient elution consisting of variable mixtures of formic acid (0.3%) in acetonitrile and formic acid (0.3%) in water. The mass spectrometer was operated in the positive ESI mode using multiple reaction monitoring. For OTA the precursor ion was m/z 404 while the product ions were at m/z 239 and m/z 341. For OTB the precursor ion was m/z 370 while the product ions were at m/z 205 and at m/z 324. A calibration curve of fortified kidney samples was used to quantify OTA. Method validation was performed according to Commission Decision 2002/657/EC. Decision limit (CCα), detection capability (CCβ), precision, bias, trueness, specificity and measurement uncertainty were determined. In general, the best results were obtained using SAX clean‐up. CCα and CCβ were 0.11 and 0.25 μg kg−1, respectively. Within‐laboratory reproducibility (% CV) was 9, 9, and 5% for OTA‐fortified kidney samples of 0.5, 1, and 2.5 μg kg−1, respectively. Trueness (%) was 75, 69, and 57% for OTA‐fortified kidney samples at 0.25, 0.5, and 1 μg kg−1, respectively. Measurement uncertainty and expanded uncertainty were 14.85 and 29.70%, respectively. All criteria as laid down in Commission Decision 2002/657/EC were fulfilled. Therefore, this LC/ESI‐MS/MS method can be used to monitor kidneys for OTA in the framework of Council Directive No. 96/23/EC. Copyright © 2004 John Wiley & Sons, Ltd.
A “Common” surgery curriculum: Health care delivery and undergraduate surgical education in Australian teaching hospitals
Authors: Prideaux David J. , Marshall Villis R. 
Published: October 2004

AbstractUndergraduate surgical education should focus on common surgical conditions and management principles. It has become increasingly difficult in Australia because of the changed patient mix in teaching hospitals. There has been an increased number of emergency admissions with a consequent reduction in elective surgery and pressure on inpatient and outpatient referrals. In addition, cost cutting has led to the intensification of staff workloads, thereby reducing potential time for teaching. Australian teaching hospitals are also tertiary referral centers. As such they have become more specialized with a more rapid turnover of acutely ill patients undergoing complex technologic treatments. More diagnosis and management of surgical conditions is conducted in ambulatory settings and through office and day surgery. The Heaslip Project at Flinders University was set up to evaluate and reform the undergraduate surgery curriculum. Graduate and student surveys revealed a need to concentrate on teaching about common surgical conditions, developing proficiency in skills and procedures and providing experience in the common principles of surgical care. These areas have now become the major components of changed surgery clerkships. Studients also spend more time interacting with patients, participating in the planning and management of preoperative and postoperative care, and working in outpatient clinics. Although the reforms have addressed the identified concerns, they may not be sufficient if the patient mix in teaching hospitals continues to narrow. Teaching hospitals will continue to provide valuable educational experiences, but they should be supplemented and complemented with the experience of managing surgical patients in the wider community.
Health care delivery system in Australia and its effect on surgical education and training
Authors: Egerton William S. 
Published: October 2004

AbstractSurgical education and training in Australia and New Zealand are based on 6‐year undergraduate medical curricula covering the scientific foundations of medical practice. One‐year rotating internships are required in all states of Australia to allow medical graduates to satisfy statutory requirements for completing basic medical education prior to gaining credit for training within a specialty. The Royal Australasian College of Surgeons defines the duration and content of training as well as the standards of supervision and guidance that enable surgical trainees to satisfy the requirements leading to Fellowship of the Royal Australasian College of Surgeons. Licensing authorities in several states and the Commonwealth of Australia recognize the award of Fellowship of the Royal Australasian College of Surgeons as sufficient evidence of competence to practice as a specialist surgeon. No formal process of recertification of surgical competence has yet been promulgated in Australia.
Health care system and medical education in Canada. 1. Review of the health care context in a time of change
Authors: Cohen Adrianne H. , Cohen Robert , Taylor Bryce R. , Reznick Richard K. 
Published: October 2004

AbstractOver the past three decades Canada has developed an exemplary system of universal health care. However, current financial constraints threaten to undermine the very foundation of the system that represents Canada's respect for social justice. The first of these two articles (Part 1) discusses the unique characteristics of the system, a comparative view of universal health care systems, the reaction of the medical profession to governmental control, and finally the funding and manpower shortages that are compelling a review of the values and organization that have sustained the system thus far. The second article (Part 2) reviews the organization and funding of medical education and the impact of some critical changes in the health care system on postgraduate medical education. Issues related to new licensure and certification requirements, changing population demographics and approaches to health care delivery, manpower needs, and the attitude and expectations of the public are discussed.
Health care system and medical education in Canada. 2. Impact of changes in the health care system on medical education
Authors: Cohen Robert , Cohen Adrianne H. , Reznick Richard K. , Taylor Bryce R. 
Published: October 2004

AbstractOver the past three decades Canada has developed an exemplary system of universal health care. However, current financial constraints threaten to undermine the very foundation of the system that represents Canada's respect for social justice. The first of these two articles (Part 1) discusses the unique characteristics of the system, a comparative view of universal health care systems, the reaction of the medical profession to governmental control, and finally the funding and manpower shortages that are compelling a review of the values and organization that have sustained the system thus far. The second article (Part 2) reviews the organization and funding of medical education and the impact of some critical changes in the health care system on postgraduate medical education. Issues related to new licensure and certification requirements, changing population demographics and approaches to health care delivery, manpower needs, and the attitude and expectations of the public are discussed.
Health care delivery system in France: Effects on surgical education
Authors: Nordlinger Bernard , Ségouin Christophe , Parc Rolland 
Published: October 2004

AbstractSurgical education in France has changed in recent years. It had to conform to the transformation of surgery into a more scientific discipline, to European Community regulations, and to increasing costs of health care. It is now organized on a national scale and is based on anomymous selection. The main objective is to train general surgeons who only afterward become specialized in various surgical specialties. The aim is to make them able to adapt to the changes that will transform surgery in the near future. In France the obligatory social insurance system, called Social Security, reimburses most medical expenses for 99% of the population. Patients can be reimbursed in a similar way whether they seek treatment in a private or a public institution. However, the system has to face major and presently unsolved problems due to the rapidly increasing cost of health care.
Health care delivery system and surgical education in India
Authors: Apte Nikantha K. , Kerkar Prafulla G. 
Published: October 2004

AbstractIn India health care delivery and medical education are largely governmental functions. India cannot afford a national health service. However, it has a national health policy based on the primary health care approach, with emphasis on rural health in order to achieve the World Health Organization's goal of “Health for All” by 2000 ad. Health care delivery is represented by the public sector as well as the private sector. Nearly 80% of the health facilities, both public and private, are concentrated in the urban areas. Hence despite its best efforts, the government has not been able to make medical education need‐based. The postgraduate surgical trainees are not exposed to rural work owing to inadequate facilities and resources in rural areas. Surgical residents get their training in teaching hospitals located in urban areas. Most of the public sector teaching hospitals are well equipped to impart training to the residents according to the guidelines of the Medical Council of India (MCI), the apex governing body. However, with the rapid advancement in medical technology over the last decade, the government is finding it increasingly difficult to keep these teaching hospitals up‐to‐date. Of late, some of the sophisticated private sector hospitals are therefore sharing the onus of surgical education, especially at the subspeciality level. Thus despite the good intentions of government planning a two class system of health care delivery has come into being and a two class system of medical education is foreseeable.
Swiss health care delivery system: Impact of financial restrictions on surgical education
Authors: Wagner Hans E. , Matter Peter 
Published: October 2004

AbstractIn 1990 Swiss health care expenditures totaled 26.3 billion Swiss francs, corresponding to 7.8% of the gross national product. Over the last 5 years expenditures have increased by 43.1%. Give the economic and political realities, future endeavors must be directed at stemming escalating costs. As 51.5% of health care resources are spent on hospital care, a substantial portion of financial restrictions and reorganization have been directed at this sector. These restrictions on hospital care have a direct impact on surgical practice and education.The resulting concentration of manpower and resources demand a new definition of the role of the general surgeon within the revised hospital system. In the face of a dilution of experience and knowledge due to an increasing number of specialized surgeons, the role of the general surgeon who provides basic surgical care must be redefined. These new trends must also be integrated into future training programs. The introduction of a structured surgical curriculum can limit the number of surgical trainees and maintain a high standard of quality.
Changing patterns in graduate surgical education in The Netherlands
Authors: Zwierstra Rein P. , Scherpbier Albert J. J. A. , van Schilfgaarde Reinout 
Published: October 2004

AbstractAn overview is presented of the organization, outline, and contents of graduate surgical training programs in The Netherlands. Adaptations of these programs to changes in demands in surgical practice and health care delivery systems are discussed. Special emphasis is given to the relation of surgery and the surgical specialties, additional training, theoretic training, and manpower planning. The principal questions regarding the optimal way to respond to changing concepts in the field of surgery are presented and discussed in the context of the situation in The Netherlands, but they seem to be similar in the surgical communities of many countries.
Health care delivery systems: Effects on surgical education in the United Kingdom
Authors: Brearley Stephen 
Published: October 2004

AbstractSurgical education in the United Kingdom has evolved to meet the need of the National Health Service (NHS) for a relatively small body of consultants practicing autonomously and carrying ultimate clinical responsibility for their patients. This form of specialist practice is markedly different from that found in most other countries and has necessitated a longer, more comprehensive training program than is usual where hospital specialists work more in teams and under the supervision of a head of department. Because the ratio of specialists to population is low, case loads are high. Trainees obtain excellent experience and rapidly assume clinical responsibility. Service commitments have increasingly conflicted with the need for more formal educational activity, and the financial problems of the NHS have latterly reduced opportunities for clinical training as well. Scientific advances in surgery have removed a range of cases from the operative repertoire of younger trainees. As a result, it is becoming increasingly difficult to provide trainees with opportunities to develop their surgical skills. The duration of surgical training in the United Kingdom is largely dictated by the availability of consultant posts. It could be shortened substantially with no loss of quality, but only if considerable additional funding were made available to the NHS. There seems little prospect of this boost at present and the impoverishment of the NHS is having an increasingly detrimental effect on standards of surgical education.
The push toward generalism: A view from surgery
Authors: Stone Michael D. , Steele Glenn , Doyle Jennifer 
Published: October 2004

AbstractRecent proposals for health care reform center on restructuring the physician workforce in favor of more “generalists.” These plans are based on several assumptions that have been neither clearly argued nor proved. Despite this, each of the plans enuciated thus far dictate that primary care physicians comprise at least 50% of the nation's physician workforce. Such a mandate has enormous repercussions for medical education. This paper takes issue with several assumptions underlying these reform initiatives, particularly the assumption that primary care does not include surgery. Because of the primary nature of surgical care, the prevalence of surgical diseases, the projected shortage of physicians entering general surgery, and the fact that surgical care is most effectively and efficiently provided by general surgeons, general surgery should not be handicapped as it would under present reform proposals. We recommend that the assumptions underlying plans to restructure the nation's physician workforce be tested, and that any reform enacted be based on rational criteria linked to the projected prevalence of disease in the nation as well as a determination of which practitioners care for those diseases most effectively and efficiently. We further recommend that medical students' time in surgical activities be increased rather than decreased, that general surgeons increase their activity in medical school curricular development and teaching, and that surgeons become involved more actively in the graduate training of primary care physicians.
Unexpected difficulties in randomizing patients in a surgical trial: A prospective study comparing extracorporeal shock wave lithotripsy with open cholecystectomy
Authors: Plaisier P. W. , Berger M. Y. , van der Hul R. L. , Nijs H. G. T. , den Toom R. , Terpstra O. T. , Bruining H. A. 
Published: October 2004

AbstractShortly after extracorporeal shock wave lithotripsy (ESWL) was introduced as a promising new treatment modality for gallstone disease, a randomized controlled study was performed to assess the cost‐effectiveness of ESWL compared to open cholecystectomy, the gold standard. During the performance of this study it was found that during a 3‐year intake period only 8.3% (37 of 448) of the patients could be entered into the trial. Three factors were identified that hampered patient accrual: (1) restricted eligibility for ESWL (and thus for the study), which could not have been predicted on the data provided in the literature; (2) the introduction of laparoscopic cholecystectomy; and (3) strong patient preference, inhibiting randomization. All three mechanisms could not have been predicted during the design phase of the study. It is concluded that it is not always feasible to conduct a randomized study in surgery due to unforeseen circumstances. Entering patients into surgical trials is difficult in quickly evolving fields of surgery, such as the management of gallstone disease. Acquiring informed consent is also difficult when treatment characteristics are divergent. A randomized controlled study on the effects of laparoscopic cholecystectomy will therefore probably nerver be performed.