bluuebunny/crossref_metadata_2025 huggingface dataset:
An Innovative Approach to the Synthesis of Anellated [a]Diaza‐anthracenones Through Tandem Cyclization.
Authors: Sharon Ashoke , Maulik Prakas R. , Roy Raja , Ram Vishnu Ji
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
A Novel One‐Pot Four‐Component Access to Tetrahydro‐β‐carbolines by a Coupling‐Amination‐Aza‐Annulation‐Pictet—Spengler Sequence (CAAPS).
Authors: Karpov Alexei S. , Oeser Thomas , Mueller Thomas J. J.
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
New Derivatives of Pyrrolo[3,4‐d]pyridazinone and Their Anticancer Effects.
Authors: Malinka Wieslaw , Redzicka Aleksandra , Lozach Olivier
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
A New Regioselective Synthesis and Bioactivity of 1H‐Pyrazolo[3,4‐d]pyrimidin‐4(5H)‐one Derivatives.
Authors: Wang Hong‐Qing , Liu Zhao‐Jie , Yang Li‐Min , Ding Ming‐Wu
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Antimicrobial Evaluation of 3‐Hydrazinoquinoxaline Derivatives and Their Cyclic Analogues.
Authors: El‐Bendary E. R. , Goda F. E. , Maarouf A. R. , Badria F. A.
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Convenient Synthesis of Phosphonate Derivatives of 4‐Chloro‐2H‐chromenes.
Authors: Modranka R. , Ochocki J.
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Desymmetrization of a meso‐Diol Complex Derived from [Cr(CO)3(η6‐5,8‐Naphthoquinone)]: Use of New Diamine Acylation Catalysts.
Authors: Kuendig E. Peter , Lomberget Thierry , Bragg Ryan , Poulard Cyril , Bernardinelli Gerald
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
N‐Acyl‐α‐triphenylphosphonioglycinates in the Synthesis of α,β‐Dehydro‐α‐amino Acid Derivatives.
Authors: Mazurkiewicz Roman , Kuznik Anna , Grymel Miroslawa , Kuznik Nikodem
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Hexafluoroacetone as Protecting and Activating Reagent. A New Approach to N‐Glycosides.
Authors: Boettcher Christoph , Spengler Jan , Essawy Samy A. , Burger Klaus
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
A Surprising Dipolar Cycloaddition Provides Ready Access to Aminoglycosides.
Authors: Dahl Russell S. , Finney Nathaniel S.
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
A Synthetic Route to Anandamide Analogues Carrying a Substituent at the Terminal Carbon and an Acetylene Group in the End Pentyl Chain
Authors: Altundas Ramazan , Mahadevan Anu , Razdan Raj K.
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Ultrahigh‐Quality Silicon Carbide Single Crystals.
Authors: Nakamura Daisuke , Gunjishima Itaru , Yamaguchi Satoshi , Ito Tadashi , Okamoto Atsuto , Kondo Hiroyuki , Onda Shoichi , Takatori Kazumasa
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Environmentally Benign Preparation of Metal Nano‐particles by Using Water‐in‐CO2 Microemulsions Technology
Authors: Liu Juncheng , Ikushima Yutaka , Shervani Zameer
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Iron(0) Complexes Derived from α,β.‐Unsaturated Ketone Analogues Bearing β‐Positioned Functional Groups
Authors: Ortega Carmen , Gutierrez Rene , Sharma Pankaj , Gomez Elizabeth , Toscano Alfredo , Lopez Jose G. , Penieres Guillermo , Alvarez Cecilio
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Organometallic Complexes of Gold
Authors: Schmidbaur H. , Schier A.
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Tridentate Aryloxide Ligands: New Supporting Ligands in Coordination Chemistry of Early Transition Metals
Authors: Matsuo Tsukasa , Kawaguchi Hiroyuki
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Zeolite‐Based Photocatalysts
Authors: Corma Avelino , Garcia Hermenegildo
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Perfluoroorganosilver(I) Compounds
Authors: Tyrra Wieland , Naumann Dieter
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Discovering Drugs Through Biological Transformation: Role of Pharmacologically Active Metabolites in Drug Discovery
Authors: Fura Aberra , Shu Yue‐Zhong , Zhu Mingshe , Hanson Ronald L. , Roongta Vikram , Humphreys Griffith W.
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Carbon Nanotubes: Substrates for a Novel Chemistry?
Authors: Krueger Anke
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Iodine Electrophiles in Stereoselective Reactions: Recent Developments and Synthetic Applications
Authors: French Andrew N. , Bissmire Stewart , Wirth Thomas
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Polyfection as Nonviral Gene Transfer Method — Design of Novel Nonviral Vector Using α‐Cyclodextrin
Authors: Arima Hidetoshi
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Asymmetric Phase‐Transfer Catalysis Utilizing Chiral Quaternary Ammonium Salts: Asymmetric Alkylation of Glycine Imines.
Authors: Lygo Barry , Andrews Benjamin I.
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Catalytic, Thermal, Regioselective Functionalization of Alkanes and Arenes with Borane Reagents
Authors: Hartwig John F.
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
DDS and Me
Authors: Mayumi Tadanori
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Relationship of HSP70 to Temperature‐Dependency of Influenza Viral Infection
Authors: Hirayama Etsuko
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Injectable Scaffolds for Tissue Regeneration
Authors: Hou Qingpu , De Bank Paul A. , Shakesheff Kevin M.
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Design of Acid—Base Catalysis for the Asymmetric Direct Aldol Reaction
Authors: Saito Susumu , Yamamoto Hisashi
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Novel Scoring Methods in Virtual Ligand Screening
Authors: Pick Daniel
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
Atropisomerism, Biphenyls, and Fluorine: A Comparison of Rotational Barriers and Twist Angles
Authors: Leroux Frederic
Published: October 2004

For Abstract see ChemInform Abstract in Full Text.
A randomized, controlled, clinical trial of activity therapy for apathy in patients with dementia residing in long‐term care
Authors: Politis Antonios M. , Vozzella Stephen , Mayer Lawrence S. , Onyike Chiadi U. , Baker Alva S. , Lyketsos Constantine G.
Published: October 2004

Background

Apathy is a common symptom in patients with dementia and has adverse consequences for patients and caregivers. Most treatments for apathy, particularly non‐pharmacologic interventions, have not been evaluated in controlled trials.

Objectives

This study evaluated the efficacy of a kit‐based activity intervention, compared to a time and attention control (one‐on‐one meetings with an activity therapist) in reducing apathy and improving quality of life in 37 patients with dementia.

Methods

The design was a randomized, controlled, partially masked clinical trial. All outcome measures were administered at baseline and follow‐up. The primary outcome measure was the apathy score of the Neuropsychiatric Inventory (NPI). Other outcome measures were the NPI total score, the Alzheimer Disease Related Quality of Life scale(ADQRL), and the Copper Ridge Activity Index (CRAI).

Results

There was a significant reduction in NPI apathy scores in both treatment groups. The only significant difference between the two treatment groups was a modest advantage for the control intervention on the CRAI cueing subscale (p = 0.027), but not on the other CRAI subscales. There was also a greater within group improvement in quality of life ratings in the control intervention (p = 0.03).

Conclusions

Despite the substantial improvement in apathy scores during the course of the study, there was no clear advantage to the reminiscence‐based intervention over the time and attention, one‐on‐one control intervention. More research is needed to develop specific behavioral interventions for apathy in patients with dementia. Copyright © 2004 John Wiley & Sons, Ltd.
Hydroxyapatite and titania sol–gel composite coatings on titanium for hard tissue implants; Mechanical and in vitro biological performance
Authors: Kim Hae‐Won , Kim Hyoun‐Ee , Salih Vehid , Knowles Jonathan C.
Published: October 2004

Hydroxyapatite (HA) composites with titania (TiO2) up to 30 mol % were coated on a titanium (Ti) substrate by a sol–gel route, and the mechanical and biological properties of the coating systems were evaluated. Using polymeric precursors, highly stable HA and TiO2 sols were prepared prior to making composite sols and coatings. Coatings were produced under a controlled spinning and heat treatment process. Pure phases of HA and TiO2 were well developed on the composites after heat treatment above 450°C. The HA–TiO2 composite coating layers were homogeneous and highly dense with a thickness of about 800–900 nm. The adhesion strength of the coating layers with respect to Ti substrate increased with increasing the TiO2 addition. The highest strength obtained was as high as 56 MPa, with an improvement of about 50% when compared to pure HA (37 MPa). The osteoblast‐like cells grew and spread actively on all the composite coatings. The proliferation and alkaline phosphatase (ALP) activity of the cells grown on the composite coatings were much higher than those on bare Ti, and even comparable to those on pure HA coating. Notably, the HA–20% TiO2 composite coating showed a significantly higher proliferation and ALP expression compared to bare Ti (p < 0.05). These findings suggest that the sol–gel‐derived HA–TiO2 composite coatings possess excellent properties for hard tissue applications from the mechanical and biological perspective. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 72B: 1–8, 2005
Rationally designed mutations convert complexes of human recombinant T cell receptor ligands into monomers that retain biological activity
Authors: Huan Jianya Y , Meza‐Romero Roberto , Mooney Jeffery L , Chou Yuan K , Edwards David M , Rich Cathleen , Link Jason M , Vandenbark Arthur A , Bourdette Dennis N , Bächinger Hans‐Peter , Burrows Gregory G
Published: October 2004

Single‐chain human recombinant T cell receptor ligands derived from the peptide binding/TCR recognition domain of human HLA‐DR2b (DRA*0101/DRB1*1501) produced in Escherichia coli with and without amino‐terminal extensions containing antigenic peptides have been described previously. While molecules with the native sequence retained biological activity, they formed higher order aggregates in solution. In this study, we used site‐directed mutagenesis to modify the β‐sheet platform of the DR2‐derived RTLs, obtaining two variants that were monomeric in solution by replacing hydrophobic residues with polar (serine) or charged (aspartic acid) residues. Size exclusion chromatography and dynamic light scattering demonstrated that the modified RTLs were monomeric in solution, and structural characterization using circular dichroism demonstrated the highly ordered secondary structure of the RTLs. Peptide binding to the ‘empty’ RTLs was quantified using biotinylated peptides, and functional studies showed that the modified RTLs containing covalently tethered peptides were able to inhibit antigen‐specific T cell proliferation in vitro, as well as suppress experimental autoimmune encephalomyelitis in vivo. These studies demonstrated that RTLs encoding the Ag‐binding/TCR recognition domain of MHC class II molecules are innately very robust structures, capable of retaining potent biological activity separate from the Ig‐fold domains of the progenitor class II structure, with prevention of aggregation accomplished by modification of an exposed surface that was buried in the progenitor structure. Copyright © 2004 Society of Chemical Industry
Production of chitinolytic enzymes by Serratia marcescens QMB1466 using various chitinous substrates
Authors: Green Andrew T , Healy Michael G , Healy Adrienne
Published: October 2004

The chitinolytic activity of submerged cultures of Serratia marcescens QMB1466 in media containing four forms of chitin as the main substrate was investigated via a full factorial design experiment with pH, temperature and substrate concentration as the main parameters. At the optimum conditions (pH 7.0, 32.5 °C and 1.0% (w/v) substrate), bioprocessed chitin (BP), isolated by lactic acid fermentation of prawn shell (Nephrops sp), induced a higher level of enzyme activity than untreated prawn shell and colloidal chitin but not that of a chemically isolated chitin (CP). The optimal conditions of pH and temperature were then applied in a bench‐top bioreactor and the chitinolytic activity monitored temporally under the influence of higher concentrations of BP and CP. Increasing the concentration of substrate in the bioreactor (>1.0% w/v) was found to inhibit the enzyme activity of the bacteria. The enzyme mixtures in selected 120‐h culture supernatants were separated by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) and the main proteins characterised by molecular weight. The electrophoretic patterns obtained from cultures from different experiments and by the different chitin substrates showed marked similarity and the main proteins isolated were largely homologous to well‐documented chitinases found in the literature. BP chitin was found to be an efficient elicitor of chitinolytic activity from this bacterium and hence is a suitable substrate to employ in an integrated biotechnological process, whereby several commercially applicable products can be obtained from a waste product of the fishing industry. Copyright © 2004 Society of Chemical Industry
Xylitol production via catalytic hydrogenation of sugarcane bagasse dissolving pulp liquid effluents over Ru/C catalyst
Authors: Baudel HM , Abreu CAM de , Zaror CZ
Published: October 2004

Xylose‐rich liquid effluents generated by the acid hydrolysis of sugarcane bagasse for production of dissolving pulp were converted to xylitol, a highly valued chemical specialty, via catalytic hydrogenation over Ru/C. From the eco‐efficiency standpoint, this initiative emerges as an attractive way to promote a chemical valorisation of bagasse dissolving pulp wastewaters. Copyright © 2004 Society of Chemical Industry
Ultrasound‐activated Knoevenagel condensation of malononitrile with carbonylic compounds catalysed by alkaline‐doped saponites
Authors: Martín‐Aranda RM , Ortega‐Cantero E , Rojas‐Cervantes ML , Vicente‐Rodríguez MA , Bañares‐Muñoz MA
Published: October 2004

α,β‐Unsaturated nitriles have been synthesized by Knoevenagel condensation of a carbonylic compound with malononitrile, assisted by sonochemical irradiation. Two alkaline‐promoted clays (Li+‐ and Cs+‐exchanged saponites) have been employed as catalysts. The influence of the carbonylic compound (benzaldehyde or cyclohexanone) and the use of a solvent on the catalytic activity have been studied. Remarkable increase in the conversion values has been found when the reaction is activated by ultrasound, as compared with the thermal activation. In this green, solvent‐free procedure, α,β‐unsaturated nitriles have been produced in very high yields (97%) when the Cs+‐saponite is used as catalyst. Copyright © 2004 Society of Chemical Industry
Loud noise enhances nigrostriatal dopamine toxicity induced by MDMA in mice
Authors: Gesi Marco , Ferrucci Michela , Giusiani Mario , Lenzi Paola , Lazzeri Gloria , Alessandrì Maria G. , Salvadorini Alessandra , Fulceri Federica , Pellegrini Antonio , Fornai Francesco , Paparelli Antonio
Published: October 2004

The neurotoxicity of 3,4‐methylenedioxymethamphetamine (MDMA, ecstasy) has been intensely investigated due to the widespread abuse of this drug and its neurotoxic effects. In mice, MDMA neurotoxicity has been demonstrated for striatal dopamine (DA) terminals. However, the current literature has reported great variability in the effects induced by MDMA; this is partially due to changes in environmental conditions. For instance, elevated temperature and a crowded noisy environment markedly increase the neurotoxic effects induced by MDMA. The environmental factor loud noise is often present during ecstasy intake; however, only a few studies have analysed the consequence of a concomitant exposure to loud noise and ecstasy intake. In the present experimental work, we investigated whether nigrostriatal DA toxicity occurring after MDMA administration was potentiated in the presence of loud noise (100 dBA). We administered MDMA to C57/Black mice using a “binging” pattern for two durations of white noise exposure. We found a marked enhancement of MDMA toxicity (7.5 mg/Kg ×4, 2 hours apart, i.p.) in the presence of white noise exposure lasting for at least 6 hours. The striatal damage was assessed by assaying DA levels as well as the loss of tyrosine hydroxylase (TH) and the increase in striatal glial fibrillary acidic protein (GFAP) immunohistochemistry. Since loud noise often accompanies ecstasy intake, the present findings call for more in‐depth studies aimed at disclosing the fine mechanisms underlying this enhancement. Microsc. Res. Tech. 64:297–303, 2004. © 2004 Wiley‐Liss, Inc.
Influence of cowpea (Vigna unguiculata L Walp) variety on protein quality and sensory properties of akara, a popular West African cowpea‐based food
Authors: Giami SY
Published: October 2004

The influence of newly developed cowpea varieties (IT81D‐699, IT82E‐18, IT84S‐2246‐4 and TVx3236) on the proximate composition, protein quality and sensory properties of akara, a popular West African cowpea‐based food, was investigated and the results obtained were compared with those for akara prepared from a local blackeye cowpea variety. Protein quality was evaluated using weanling albino rats fed diets which were formulated to supply 10% protein using defatted akara samples, with casein as a control. Akara samples prepared from IT81D‐699 and TVx3236 had crude protein contents, texture and overall acceptability comparable to those of akara prepared from the blackeye variety. Also, akara diets formulated using IT81D‐699 and TVx3236 showed significantly (p < 0.05) higher values for weight gain, protein efficiency ratio, net protein ratio and true digestibility than diets formulated with IT82E‐18, IT84S‐2246‐4 and blackeye, suggesting an improvement in the nutritional quality of akara produced using these (IT8ID‐699 and TVx3236) newly developed cowpea varieties. Copyright © 2004 Society of Chemical Industry
Effect of glycols on the properties of polyester polyols and of room‐temperature‐curable casting polyurethanes
Authors: Zhang Chen , Feng Shengyu
Published: October 2004

A series of liquid polyester polyols (PEs) from adipic acid (AA), phthalic anhydride (PA) and trihydroxymethylpropane (TMP), and such glycols as ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), butanediol (BD) and hexanediol (HD), were prepared. Polyurethanes (PUs) were obtained from the PEs and polyaryl polymethylene isocyanate (PAPI) at room temperature. The effects of the structures of the glycols on viscosity, glass transition temperature and crystallinity of the PEs, and the mechanical, thermal and boiling‐water‐resistant properties of PUs were studied. The experiments showed that the viscosities and glass transition temperatures of the PEs decreased as the length of the glycol chains increased. The polyester based on HD lost flowability because of crystallization. The tensile strength and hardness of the PUs obtained decreased with increasing the length of the glycol chains, while the resistance to thermal deformation and boiling water increased. Thermogravimetric analysis demonstrated that thermal degradation of the polyurethane based on DEG proceeded in one step and for the others in two steps. The initial degradation temperature of the polyurethane based on EG was the lowest and that of the polyurethane based on BD was the highest. The residue of the former at 450 °C was the greatest, while that of the latter was the lowest. Copyright © 2004 Society of Chemical Industry
A study of the crystalline transitions of polyamides X 18
Authors: Cui Xiaowen , Li Weihua , Yan Deyue
Published: October 2004

The crystalline transition behavior of polyamides X 18, where X = 2, 4, 6, 8, 10 and 12, has been studied by variable‐temperature wide‐angle X‐ray diffraction (WAXD) and real‐time Fourier‐transform infrared (FTIR) spectroscopy. It was found that polyamides 2 18 and 4 18 undergo the Brill transition on heating for both the melt‐crystallized samples and the solution‐crystallized samples. For polyamide 6 18, the melt‐crystallized sample undergoes Brill transition before melting but the solution‐crystallized sample melts prior to the complete crystalline transition. Polyamides 8 18, 10 18 and 12 18 do not undergo the Brill transition perfectly in advance of melting for either melt‐crystallized or solution‐crystallized samples. Real‐time FTIR analysis of polyamides X 18 provided helpful information for understanding the mechanism of the crystalline transition. Copyright © 2004 Society of Chemical Industry
Starch‐based biodegradable blends: morphology and interface properties
Authors: Schwach Emmanuelle , Avérous Luc
Published: October 2004

In order to improve the properties of plasticized wheat starch (PWS) and to conserve its final biodegradability, PWS can be blended with biodegradable polyesters [polyesteramide, poly(ε‐caprolactone), poly(lactic acid), poly(butylene succinate adipate) and poly(butylene adipate terephthalate)] which exhibit variable polar characteristics. This paper is focused on the analysis of the compatibility of these blends which vary according to their formulation. To understand the lack of affinity between the different phases, interface adhesion has been investigated by contact angle measurements to obtain the work of adhesion. From these determinations a forecast approach has been developed to predict blend compatibility. Blend structures were obtained by scanning electron microscopy observations. Blends show either a dispersed structure or a co‐continuous morphology. Percolation thresholds (co‐continuity) and full continuity regions were determined thanks to a method based on solvent extraction. Finally, rheological investigations have been carried out on the different biodegradable polymers to understand better the blend structure formation during the process. Copyright © 2004 Society of Chemical Industry
Ionic conductivity of multiarm star polymer/LiClO4 electrolytes
Authors: Yang Xiaohui , Sun Xiaoying , Shao Jiajia , Liu Yunhang , Wang Xinling
Published: October 2004

A series of polymer electrolytes based on multiarm polymers and lithium salt complexes were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and impedance measurement. The relationships of conductivity with salt concentration, temperature, and arm numbers are discussed. It is suggested that the star polymer has a higher solvency and ion transfer ability on lithium salts than on linear polymers. The conductivity maximum appeared at a higher salt concentration ([EO]/[Li] = 4). Impedance measurement suggested that the optimum conductivity was 2 × 10−4 s · cm−1. The conductivity increased with temperature and the dependence of ionic conductivity on temperature fits the Arrhenius equation. Among the studied systems, the star polymer with a five arm number performs better than other structures. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4195–4198, 2004
Can chest X‐ray predict pneumonia severity?
Authors: Grafakou Olga , Moustaki Maria , Tsolia Maria , Kavazarakis Emmanuel , Mathioudakis John , Fretzayas Andrew , Nicolaidou Polyxeni , Karpathios Themistokles
Published: October 2004

Predictors of the severity of pneumonia have not been thoroughly evaluated among children in developed countries. We investigate whether chest radiographic findings could be used as predictors of severity of childhood pneumonia. The study included 167 children, aged more than 12 months, hospitalized in our department during a 4‐year period with unilateral lobar or segmental pneumonia. The durations of fever and of hospitalization were considered indicators of severity of the disease. The size of the consolidation and its location in the left hemithorax were independently associated with severity of the disease. Univariate analysis showed that the mean duration of fever and of hospitalization as well as the prevalence of pleural effusion was significantly higher among children with left‐sided pneumonia. A multiple logistic regression analysis revealed that only the presence of pleural effusion was significantly more likely in left‐sided pneumonia (odds ratio, 2.65; 95% confidence interval, 1.09–6.47; P = 0.031). We conclude that the size of consolidation and the side of its location can be used as predictors of severity of pneumonia, with left‐sided pneumonia running a more severe course, possibly due to increased risk for the development of pleurisy. © 2004 Wiley‐Liss, Inc.
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

Ion 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

The 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

The 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

We 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

The 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

A 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

Undergraduate 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

Surgical 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

Over 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

Over 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

Surgical 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

In 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

In 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

An 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

Surgical 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

Recent 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

Shortly 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.