bluuebunny/crossref_metadata_2025 huggingface dataset:
Topotecan and cyclophosphamide in patients with refractory or relapsed Ewing tumors
Authors: Hunold Andrea , Weddeling Nicole , Paulussen Michael , Ranft Andreas , Liebscher Caren , Jürgens Herbert
Published: January 2006

Background

The prognosis of Ewing tumor (ET) patients has significantly improved to cure rates approximating 70%. The prognosis in relapse, however, is poor. Promising response rates have recently been reported for the combination of topotecan (TOPO) and cyclophosphamide (CYC) encouraging wider application of this combination in patients with relapsed ETs. This report summarizes the experience of patients treated with TOPO/CYC for recurrent or refractory disease within the German ET trials.

Procedure

Fifty‐four patients aged 3.2–49.5 (median: 17.4) years received TOPO (0.75 mg/m2/day, days 1–5) and CYC (250 mg/m2/day, days 1–5) following first (40) or second (6) relapse or progression under first‐line therapy (8).

Results

A median of 3 (range: 1–11) TOPO/CYC courses were given. Sixteen patients (32.6%) showed partial response (PR), 13/49 (26.5%) had stable disease (SD), 14/49 (28.6%) progressed, 2/49 (4.1%) showed a mixed response (MR). In 4 patients response was not documented, 5/54 patients with complete initial resection at the diagnosis of relapse were excluded from the response analysis. At completion of relapse therapy, 24/54 patients had entered complete (19) or partial (5) remission, 2 had SD, 26 showed progression, information was unavailable in 2 patients. Of the 19 relapse patients achieving complete response (CR), 10 maintained remission (52.6%). At the time of evaluation, after a median follow‐up for survivors of 23.1 (range: 7.8–59.8) months from the event prompting TOPO/CYC treatment, 14/54 patients (25.9%) were in continuous complete (13) or partial (1) remission. Overall survival (OAS) after 1 year was 0.61 (95%‐CI 0.47–0.74).

Conclusion

TOPO/CYC is active in relapsed ETs and warrants further evaluation. Pediatric Blood Cancer 2006;47:795–800. © 2006 Wiley‐Liss, Inc.
Langerhans cell histiocytosis infiltration into pancreas and kidney
Authors: Goyal Richa , Das Ashim , Nijhawan Raje , Bansal Deepak , Marwaha Ram Kumar
Published: January 2006

An 18‐month‐old male presented with a swelling of the neck for 2 months. A presumptive diagnosis of Langerhans cell histiocytosis (LCH) was made on fine needle aspiration cytology from the lymph node. The child received chemotherapy. He remained well for around 10 months, when he represented with loose stools, cough, and respiratory distress. His condition deteriorated over a few hours culminating in death. A partial autopsy revealed LCH infiltration in liver, pancreas, and kidneys along with bronchopneumonia. The pancreatic and renal infiltration by LCH is extremely rare. Pediatr Blood Cancer 2007;49:748–750. © 2006 Wiley‐Liss, Inc.
Evaluation of persistent pulmonary infiltrates in pediatric oncology patients
Authors: Armenian Saro H. , La Via William V. , Siegel Stuart E. , Mascarenhas Leo
Published: January 2006

Purpose

To evaluate the role of bronchoalveolar lavage (BAL), computed‐tomography‐guided biopsy (CTB), and open lung biopsy (OLB) in the management of persistent pulmonary infiltrates in pediatric oncology patients.

Methods

Retrospective review of clinical records of pediatric oncology patients who underwent BAL, CTB, and OLB over a 7‐year period. Data was compared across the three procedures using chi‐square analysis. Logistic regression was used to adjust potential confounding variables for diagnostic yield.

Results

There were 113 consecutive patients who underwent 140 separate procedures during their hospitalization. Thirty (26%) patients had a previous BMT. BALs were more likely to occur as the first line of investigation (98% vs. 47%, 45%; P < 0.01) and in patients with diffuse infiltrates (64% vs. 6%, 26%; P < 0.01) when compared to CTB and OLB, respectively. OLBs were performed less frequently in neutropenic patients (26% vs. 53%, 54%; P < 0.05), more often led to change in management directly because of procedure (61% vs. 12%, 33%; P < 0.01), and had higher diagnostic yield (61% vs. 24%, 36%; P < 0.01) when compared to CTB and BAL, respectively. Diagnostic yield of OLB was significantly higher regardless of diffuse or focal nature of infiltrate. Major adverse events after a procedure were not significantly different across the three procedures. Logistic regression demonstrated that having an OLB was independently associated with identifying the cause of pulmonary infiltrate.

Conclusion

OLB appears to be safe, has the best diagnostic yield, and leads to change in management more often than CTB or BAL in pediatric oncology patients with persistent pulmonary infiltrates. Pediatr Blood Cancer 2007;48:165–172. © 2006 Wiley‐Liss, Inc.
Effective treatment of kaposiform hemangioendotheliomas associated with Kasabach–Merritt phenomenon using four‐drug regimen
Authors: Hauer Julia , Graubner Ulrike , Konstantopoulos Nikos , Schmidt Susanne , Pfluger Thomas , Schmid Irene
Published: January 2006

We report a case of a 6‐month‐old girl suffering from a kaposiform hemangioendothelioma of the chest wall, associated with Kasabach–Merritt phenomenon. Despite rapid intervention with cortisone and interferon alpha the tumor led to a life‐threatening clinical condition with progressive growth and consumption coagulopathy under therapy. Because therapy for kaposiform hemangioendotheliomas with a single anti‐angiogenic or anti‐proliferative agent has not been reported to be very successful, we administered vincristine, combined with cyclophosphamide, actinomycin D, and methotrexate in a critically ill patient. After six cycles of the applied four‐drug regiment, the infant was in remission, which has been maintained for 5 months since stopping therapy. Pediatr Blood Cancer 2007;49:852–854. © 2006 Wiley‐Liss, Inc.
Temporary diabetes mellitus secondary to a primary pancreatic Burkitt lymphoma
Authors: Meier Constance , Kapellen Thomas , Tröbs Ralph B. , Hirsch Wolfgang , Parwaresch Reto , Kiess Wieland , Körholz Dieter
Published: January 2006

Primary pancreatic lymphoma (PPL) is a rare form of extranodal lymphoma. So far, only in adults has a coincidence with diabetes mellitus (DM) been described. We report a nearly 9‐year‐old German boy presenting with a Burkitt lymphoma associated with a temporary insulin‐dependent DM and exocrine insufficiency of the pancreas. After the patient went into remission, a spontaneous recovery of the endocrine pancreatic function was observed. On immunophenotyping, the lymphoma cells revealed expression of FasL suggesting a potentially apoptotic effect on pancreatic tissue. Beta cell impairment may have been caused by FasL resembling autoimmune diabetes. Pediatr Blood Cancer © 2006 Wiley‐Liss, Inc.
Complementary and alternative medicine in pediatric oncology: Availability and institutional policies in Canada—a report from the Children's Oncology Group
Authors: Johnston Donna L. , Nagel Kim , O'Halloran Claire , Sencer Susan F. , Kelly Kara M. , Friebert Sarah , Hilden Joanne M. , Friedman Debra L.
Published: January 2006

Complementary and alternative medicine (CAM) is used frequently by pediatric oncology patients. A survey exploring the institutional practices and policies surrounding CAM use in pediatric oncology patients was completed by 17 pediatric hematology/oncology centers in Canada. We found that CAM was offered in only 18% of the institutions, but 94% of the communities. Only 6% of oncology divisions made direct referrals to community CAM providers, and only 20% of the centers had policies regarding use of CAM therapies for their patients. Despite published widespread use of CAM therapies, our study demonstrates that institutional CAM resources and policies on CAM are present in much lower proportions. Pediatr Blood Cancer © 2006 Wiley‐Liss, Inc.
Increased oxidation and degradation of cytosolic proteins in alcohol‐exposed mouse liver and hepatoma cells
Authors: Kim Bong‐Jo , Hood Brian L. , Aragon Richard A. , Hardwick James P. , Conrads Thomas P. , Veenstra Timothy D. , Song Byoung J.
Published: January 2006

We recently developed a sensitive method using biotin‐N‐maleimide (biotin‐NM) as a probe to positively identify oxidized mitochondrial proteins. In this study, biotin‐NM was used to identify oxidized cytosolic proteins in alcohol‐fed mouse livers. Alcohol treatment for 6 wk elevated the levels of CYP2E1 and nitrotyrosine, a marker of oxidative stress. Markedly increased levels of oxidized proteins were detected in alcohol‐fed mouse livers compared to pair‐fed controls. The biotin‐NM‐labeled oxidized proteins from alcohol‐exposed mouse livers were subsequently purified with streptavidin‐agarose and resolved on 2‐DE. More than 90 silver‐stained protein spots that displayed differential intensities on 2‐D gels were identified by MS. Peptide sequence analysis revealed that many enzymes or proteins involved in stress response, chaperone activity, intermediary metabolism, and antioxidant defense systems such as peroxiredoxin were oxidized after alcohol treatment. Smaller fragments of many proteins were repeatedly detected only in alcohol‐fed mice, indicating that many oxidized proteins after alcohol exposure were degraded. Immunoblot results showed that the level of oxidized peroxiredoxin (inactivated) was markedly increased in the alcohol‐exposed mouse livers and ethanol‐sensitive hepatoma cells compared to the corresponding controls. Our results may explain the underlying mechanism for cellular dysfunction and increased susceptibility to other toxic agents following alcohol‐mediated oxidative stress.
Preparation and characterization of optically active polystyrene via a chiral nitroxide‐mediated polymerization
Authors: Zhou Nianchen , Xu Wenjian , Zhang Yu , Zhu Jian , Zhu Xiulin
Published: January 2006

2,2,6,6‐Tetramethyl‐4‐[d‐(+)‐10‐camphorsulfonyl]‐1‐piperidinyloxy was synthesized and used as a chiral nitroxide for the bulk polymerizations of styrene initiated with benzoyl peroxide (BPO), tetraethylthiuram disulfide (TETD), and thermal initiation. The results showed that the polymerizations proceeded in a controlled/living way; that is, the kinetics presented approximately first‐order plots, and the number‐average molecular weights of the polymers with narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight) increased with the monomer conversion linearly. The molecular weight distributions in the case of thermal initiation were narrower than those in the case of BPO and TETD, whereas the polymerization rate with BPO or TETD as an initiator was obviously faster than that with thermal initiation. In addition, successful chain‐extension reactions were carried out, and the structures of the obtained polymers were characterized by gel permeation chromatography and 1H NMR. The specific rotations of the polymers were also measured by polarimetric analysis. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1522–1528, 2006
Synthesis of novel benzoxazines containing glycidyl groups: A study of the crosslinking behavior
Authors: Andreu R. , Espinosa M. A. , Galià M. , Cádiz V. , Ronda J. C. , Reina J. A.
Published: January 2006

Benzoxazines derived from aniline and 4‐hydroxybenzoic acid and from phenol and 4‐aminobenzoic acid were prepared with two different synthetic approaches. When the carboxylic group reacted with epichlorohydrin, glycidylic derivatives M‐1 and M‐2, respectively, were obtained. The ring opening of benzoxazine and epoxy took place simultaneously with no catalyst for both monomers. Likewise, both ring‐opening polymerizations took place when boron trifluoride monoethylamine (BF3·MEA) or 4‐(N,N‐dimethylamino)pyridine was used as a catalyst for M‐1. However, for M‐2, when BF3·MEA was used as a catalyst, the epoxy and benzoxazine ring openings could be distinguished, and a polyether intermediate containing benzoxazine side chains could be obtained. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1529–1540, 2006
Synthesis and characterization of fluorinated telomers containing vinylidene fluoride and hexafluoropropene from 1,6‐diiodoperfluorohexane
Authors: Mladenov G. , Ameduri B. , Kostov G. , Mateva R.
Published: January 2006

The synthesis of original fluorinated (co)telomers containing vinylidene fluoride (VDF) or VDF and hexafluoropropene (HFP) was achieved by radical telomerizations and (co)telomerizations of VDF (or VDF and HFP) in the presence of 1, 6‐diiodoperfluorohexane via a semisuspension process.tert‐Butyl peroxypivalate (TBPPi) was used as an efficient thermal initiator. The numbers of VDF and VDF/HFP base units in the (co)telomers were determined by19F and1H NMR spectroscopy. They ranged from 10 to 190 VDF base units. Fluorinated telomers of various molecular weights (1200–12,600 g/mol) were obtained by the alteration of the initial [1,6‐diiodoperfluorohexane]0/[fluoroalkenes]0and [TBPPi]0/[fluoroalkenes]0molar ratios. The thermal properties of these fluorinated (co)telomers, such as the glass‐transition temperature and melting temperature, were examined. As expected, these telomers exhibited good thermal stability. They were stable at least up to 350 °C. The compounds containing more than 30 VDF units were crystalline, whereas all those containing VDF‐co‐HFP were amorphous with elastomeric properties, whatever the number was of the fluorinated base units. The structures of I–(VDF)n–RF–(VDF)m–I and I–(HFP)x(VDF)n–RF–(VDF)m(HFP)y–I (co)telomers were obtained, and the defects of the VDF chain and the CH2CF2I and CF2CH2I functionalities were studied successfully (where RF= C6F12). The functionality in the iodine atoms was modified: the higher the VDF content in the telomers, the lower the normal end functionality (CH2CF2I) and the higher the reversed extremity (CF2CH2I). In addition, the percentage of defects increased when the number of VDF units increased. The molecular weights and molecular weight distributions of different telomers and cotelomers were also studied. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1470–1485, 2006
Vinyl polymerization of norbornene by bis(nitro‐substituted‐salicylaldiminate)nickel(II)/methylaluminoxane catalysts
Authors: Carlini Carlo , Martinelli Marco , Galletti Anna Maria Raspolli , Sbrana Glauco
Published: January 2006

The polymerization of norbornene has been investigated in the presence of different bis(salicylaldiminate)nickel(II) precursors activated by methylaluminoxane. These systems are highly active in affording nonstereoregular vinyl‐type polynorbornenes (PNBs) with high molecular weights. The productivity of the catalytic systems is strongly enhanced (up to 35,000 kg of PNB/mol of Ni × h) when electron‐withdrawing nitro groups are introduced on the phenol moiety. On the contrary, the presence of bulky alkyl groups on the N‐aryl moiety of the ligand does not substantially affect the activity or characteristics of the resulting PNBs. The catalytic performances are also markedly influenced by the reaction parameters, such as the nature of the solvent, the reaction time, and the monomer/Ni and Al/Ni molar ratios. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1514–1521, 2006
Chain microstructure of homogeneous ethylene‐1‐alkene copolymers and characteristics of single site catalysts using a direct13C NMR peak method. Part III. Application to ethylene–propylene copolymers showing no inversion
Authors: Karssenberg F. G. , Piel C. , Hopf A. , Mathot V. B. F. , Kaminsky W.
Published: January 2006

All relevant13C NMR signals of two series of seven homogeneous ethylene–propylene copolymers were used to fit the second‐order Markov reactivity ratios of the catalysts and the theoretical feeds. The copolymers cover a very broad range of comonomer incorporations, from about 10 to 93%, and show only primary (1,2) insertions. For both series, solutions are found with reliabilities >>99.5%. The reactivity ratios,r112= 2.54,r121= 0.12,r212= 2.05, andr221= 0.29 for the used Zirconocone andr112= 1.69,r121= 0.32,r212= 1.56, andr221= 0.51 for the hafnocene, provide direct information about the metallocenes, the kinetics, and the chain microstructure. With these results, the direct peak method demonstrates that the use of all relevant13C NMR peaks enables accurate second‐order Markov modeling, revealing subtle differences between copolymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 747–755, 2006
Influence of the efficacy of interfacial modification on the coarsening of cocontinuous PS/HDPE blends during quiescent annealing
Authors: Yuan Zhenhua , Favis Basil D.
Published: January 2006

This article studies the quiescent annealing of three different cocontinuous polystyrene/high‐density polyethylene blends modified with two types of interfacial agents of widely different efficacies. Quantitative analysis of phase growth was obtained using mercury porosimetry. In a previous work, it was shown that one of these modifiers, a symmetrical diblock copolymer, has a high affinity for the interface and demonstrates virtually no micelle formation prior to saturation of the blend interface. The other modifier, a hydrogenated SEBS of 70/30 composition, forms micelles at elevated concentrations of modifier. In this study, it is shown that the cocontinuous phase size grows linearly without modifier, whereas the addition of both interfacial modifiers significantly suppresses the PE/PS phase coarsening and results in nonlinear phase growth behavior. The effect of the diblock copolymer on suppressing coarsening, however, is much more effective than that for the triblock case clearly supporting the tendency toward micelle formation for that latter modifier. In the case of unmodified PE/PS, the driving force for capillary pressure effects is so high that it is the capillary instability phenomena that dominate the coarsening and hence result in a linear growth of pore size with annealing time. When interfacial modifiers are added, the influence of reduced interfacial tension and lower pore size polydispersity significantly diminishes both capillary pressure effects and capillary instability phenomena. In that case, capillary pressure becomes the main rate determining step resulting in a nonlinear dependence of pore size with annealing time. It is shown that both the viscosity of the phases and the temperature of annealing can strongly influence coarsening behavior at low levels of interfacial modifier. Under all those conditions, however, nonlinear phase growth for the partially compatibilized system was maintained. These results clearly show that careful quantitative coarsening experiments using mercury porosimetry can be used as a tool to analyze the efficacy of interfacial modifiers for highly continuous or cocontinuous systems. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 711–721, 2006
Collapse and swelling of poly(N‐isopropylacrylamide‐co‐sodium acrylate) copolymer brushes grafted on a flat SiO2 surface
Authors: Cheng He , Liu Guangming , Wang Chengqing , Zhang Guangzhao , Wu Chi
Published: January 2006

Poly(N‐isopropylacrylamide‐co‐sodium acrylate) copolymer brushes grafted on SiO2‐coated quartz crystal surface were prepared with a surface‐immobilized initiator. The collapse and swelling of the thermally sensitive copolymer brushes in water were studied with quartz crystal microbalance in situ. The frequency and dissipation changes with the temperature increasing in the range 20–38 °C indicate that the brushes undergo a continuous collapse transition. Our results show that the copolymer brushes collapse to a state where the brushes were prepared. A hysteresis was observed in the cooling process. Fourier transform infrared (FTIR) results revealed that the formation of some additional hydrogen bonds within the copolymer chains at their collapsed state is responsible for the hysteresis. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 770–778, 2006
Two calorimetric glass transitions do not necessarily indicate immiscibility: The case of PEO/PMMA
Authors: Lodge Timothy P. , Wood Elizabeth R. , Haley Jeffrey C.
Published: January 2006

Differential scanning calorimetry has been used to examine blends of a poly(ethylene oxide) (PEO), Mn = 300 g/mol, and a poly(methylmethacrylate) (PMMA), Mn = 10,000 g/mol, across the complete composition range. The relatively low molar mass of the PEO minimizes interference from crystallization. In the midrange of composition, ∼25–70% PEO, two broad, but distinct, glass transitions are resolved. These are interpreted as distinct glass transitions of the two components, as anticipated by the self‐concentration model of Lodge and McLeish. The composition dependence of the observed transitions is well described by the self‐concentration approach, using lengthscales of approximately two‐thirds of the Kuhn length. The results are compared with previous measurements on PEO/PMMA blends and other miscible systems. The principal, general conclusion is that one should actually expect two glass transitions in a miscible polymer blend or polymer solution; the rule of thumb that two transitions indicate immiscibility is incorrect. Furthermore, attempts to rationalize two transitions on the basis of incomplete segmental mixing, or other unspecified “nanoheterogeneity,” may not be justified in many cases. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 756–763, 2006
Effect of ethanol on folding of hen egg‐white lysozyme under acidic condition
Authors: Sasahara Kenji , Nitta Katsutoshi
Published: January 2006

The equilibrium and kinetics of folding of hen egg‐white lysozyme were studied by means of CD spectroscopy in the presence of varying concentrations of ethanol under acidic condition. The equilibrium transition curves of guanidine hydrochloride‐induced unfolding in 13 and 26% (v/v) ethanol have shown that the unfolding significantly deviates from a two‐state mechanism. The kinetics of denaturant‐induced refolding and unfolding of hen egg‐white lysozyme were investigated by stopped‐flow CD at three ethanol concentrations: 0, 13, and 26% (v/v). Immediately after dilution of the denaturant, the refolding curves showed a biphasic time course in the far‐UV region, with a burst phase with a significant secondary structure and a slower observable phase. However, when monitored by the near‐UV CD, the burst phase was not observed and all refolding kinetics were monophasic. To clarify the effect of nonnative secondary structure induced by the addition of ethanol on the folding/unfolding kinetics, the kinetic m values were estimated from the chevron plots obtained for the three ethanol concentrations. The data indicated that the folding/unfolding kinetics of hen lysozyme in the presence of varying concentrations of ethanol under acidic condition is explained by a model with both on‐pathway and off‐pathway intermediates of protein folding. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Fungicide control of mushroom cobweb disease caused by Cladobotryum strains with different benzimidazole resistance profiles
Authors: Grogan Helen M
Published: January 2006

The benzimidazole fungicides thiabendazole and carbendazim, and the imidazole fungicide prochloraz‐Mn, were tested for their efficacy in controlling cobweb disease of mushrooms caused by two Cladobotryum isolates. Isolate 202A was benzimidazole‐sensitive in vitro and cobweb growth on the casing was well controlled by both benzimidazole fungicides in cropping experiments. Carbendazim also controlled the development of spotting symptoms much more effectively than thiabendazole. A second isolate (192B1) was benzimidazole‐resistant and was highly resistant to thiabendazole in vitro but it showed some sensitivity to carbendazim in vitro at moderate to high concentrations. Despite this, carbendazim did not control disease symptoms in cropping experiments, confirming that isolate 192B1 is cross‐resistant to other benzimidazole fungicides. Both isolates showed some sensitivity to prochloraz‐Mn in vitro. This fungicide gave between 45% and 65% control of cobweb growth on the casing caused by either 202A or 192B1 but gave no control of spotting symptoms. Reducing the fungicide application volume did not give enhanced disease control. The emergence of benzimidazole resistance reduces the value of benzimidazoles in the control of mushroom pathogens. However, the lack of effective alternatives means they continue to have utility in cases where pathogens are still sensitive but this requires regular monitoring of pathogen populations for resistance. Copyright © 2006 Society of Chemical Industry
Effect of dose rate and mixtures of fungicides on selection for QoI resistance in populations of Plasmopara viticola
Authors: Genet Jean‐Luc , Jaworska Grazyna , Deparis Francine
Published: January 2006

Resistance to QoI fungicides (strobilurins, famoxadone and fenamidone) in populations of Plasmopara viticola (Berk & Curt) Berlese & de Toni developed soon after their introduction in France and Italy. Current resistance management strategies include limitation of the number of applications, use of mixtures and alternation of fungicides with different modes of action. The selection pressure resulting from QoI fungicides applied alone or in mixtures with non‐QoI fungicides was investigated in whole plant experiments under controlled conditions. QoI‐resistant populations of P. viticola gradually reverted to full sensitivity following consecutive transfers to untreated plants, suggesting that resistant phenotypes were less competitive than sensitive ones. When cycled on QoI‐treated plants, reduction in sensitivity was greater for the QoI fungicide which had greater intrinsic activity on P. viticola. Sensitivity decreased at each subsequent cycle, resulting in almost full resistance after four generations. Mixture experiments indicated that selection pressure was affected most by the dose of the QoI fungicide and the nature of the partner fungicide. Folpet delayed selection pressure most effectively when it was associated with famoxadone or azoxystrobin. Mancozeb was least effective at reducing the rate of selection compared with the QoI alone, and fosetyl‐aluminium was intermediate. Higher rates of selection were recorded when the dose of the QoI fungicide, solo or in a mixture, was increased from 1 to 4 µg ml−1. Increasing the dose of the non‐QoI partner fungicide in the mixture from 10 to 30 µg ml−1 resulted in reduced selection pressure. These results suggest that the choice of the fungicide partner and its dosage in the mixture can significantly affect the success of QoI resistance management strategies under practical conditions. Copyright © 2006 Society of Chemical Industry
A wedge disclination dipole interacting with a circular inclusion
Authors: Liu Y. W. , Fang Q. H. , Jiang C. P.
Published: January 2006

The problem involving the interaction effects between a wedge disclination dipole and an elastic circular inclusion is investigated. Utilizing the Muskhelishvili complex variable method, the closed form solutions are derived for complex potentials and stress fields due to a wedge disclination dipole located near the circular inclusion. The strain energy and the force acting on the disclination dipole center are also calculated. The influence of the orientation and the location of the disclination dipole as well as the material elastic dissimilarity upon the equilibrium position of the disclination dipole is discussed in detail. The results show that for certain combinations of materials constants, the disclination dipole has a stable equilibrium point near the inclusion. Moreover, the force on the disclination dipole is very much affected by the orientation of the disclination dipole. The present solutions contain previously known results as the special cases. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation on the optical and structural properties of spin coated CeO2–TiO2 thin films
Authors: Ghodsi F. E. , Tepehan F. Z.
Published: January 2006

Equimolar CeO2–TiO2 multi layer (3–7) thin films were prepared by spin coating technique in different spin speed (1500–4000 rpm), by using sol–gel route. The dependence of deposition conditions on the optical and structural properties of the films was investigated. Scanning electron microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS) were employed to analyze the structural properties of the films. Optical constants (refractive index, absorption coefficient, energy band gap, etc.) were determined in the 200–1100 nm wavelength range by transmission spectrophotometry. It was found that with increasing spinning rate from 1500 rpm to 4000 rpm the thickness of the films decrease from 440 nm to 229 nm while the refractive index and the absorption coefficient at 550 nm wavelength increase from 1.80 to 2.16, and 599.83 cm–1 to 1174.60 cm–1 respectively. The thickness, refractive index, and absorption coefficient of the films at 550 nm wavelength increase from 235 nm to 548 nm, 1.85 to 2.00, and 553.90 cm–1 to 1347.00 cm–1 respectively with increasing the number of coating layers from 3 to 7. The optical band gap has a value of 3.19 eV for indirect transition and is independent of spin speed and number of layers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hysteresis phenomena in (La0.83Bi0.17)0.67Ca0.33MnO3
Authors: Xia Z. C. , Zeng F. R. , Hu M. T. , Dong B. , Liu G. , Wang Y. , Feng X. N. , Liu L. , Tang C. Q. , Yuan S. L.
Published: January 2006

The temperature dependence of the resistance and magnetization of Bi3+‐doped (La0.83Bi0.17)0.67Ca0.33MnO3 is investigated, for which both thermal and magnetic hysteresis phenomena are observed. In a lower applied magnetic field range of 0 < H < 0.5 T and a temperature range of 110 < T < 200 K, a two‐step magnetization behavior with an enhanced magnetoresistance effect is observed. According to the experimental results, it is surmised that the hysteresis behavior results mainly from the coexistence of charge ordered (CO) and ferromagnetic (FM) domains, for which the CO domains have relaxation and pinning effects on the growth and rotation of FM domains. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature dependence of the energy gap of InxSe1–x compounds
Authors: Michalewicz Anna , Nowak Marian , Kępińska Mirosława
Published: January 2006

The optical absorption for photon energies of InxSe1–x thin films was used to determine the variation of the energy gap and the Urbach energy as a function of temperature in the range from 80 to 340 K at photon energies hν = 1.24 to 2.6 eV. The data were analyzed using the Varshni relation [Physica 34, 149 (1967)] for the temperature dependence of semiconductor band gaps. The formula by Yang et al. [cf., e.g., J. Phys. Chem. Solids 65, 1015 (2004)] for the temperature dependence of the energy width of the Urbach absorption edge was also used. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The isotope effect in disordered strongly coupled superconductors
Authors: Mierzyńska M. , Wysokiński K. I.
Published: January 2006

The isotope effect in disordered strongly coupled superconductors has been studied. Weakly disordered bulk s‐ and d‐wave superconductors as well as strongly disordered homogeneous and granular thin films have been considered. To treat strong coupling s‐wave superconductors Eliashberg theory has been used and the weak localization effects on isotope coefficient (IC) calculated within this approach. The interesting point is that weak localization effects known to properly describe degradation of transition temperature of s‐wave superconductors have been found to decrease the isotope coefficient of impure material with respect to pure samples. This is in contrast to the strong increase of IC induced by magnetic impurities in s‐wave or nonmagnetic impurities in d‐wave spin singlet superconductors. We have also calculated the change of isotope coefficient for both homogeneous and granular thin films and found that the effect of disorder in granular materials on the isotope coefficient is similar to that observed in high‐temperature superconductors. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A comparative study of helium atom diffusion via an interstitial mechanism in nickel and palladium
Authors: Xia Jixing , Hu Wangyu , Yang Jianyu , Ao Bingyun , Wang Xiaolin
Published: January 2006

At low temperatures, helium atoms diffuse primarily by an interstitial mechanism due to the lower activation energy. Using a modified analytic embedded‐atom model (MAEAM) and the molecular dynamics method, a study of the interstitial diffusion for helium atoms in perfect nickel and palladium was performed. Consequently, the diffusion coefficient was calculated from the jump‐frequency method. The temperature dependency of the diffusion coefficient was found to agree well with the Arrhenius relation. The activation energies of the interstitial mechanism in these two metals were obtained by fitting to the Arrhenius relation, and the results agree with the available experimental and other theoretical data. In addition, by comparing the diffusion activation energies of helium atoms in nickel and palladium, it is found that the helium atom is less mobile in palladium than in nickel. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum tunnelling and decoherence in nanomagnets
Authors: Gedik Z. , Bozat Ö.
Published: January 2006

Starting from the observation that at very low temperatures an isolated nanomagnet can be treated as an effective two‐state system, we introduce a model to study quantum tunnelling and decoherence phenomena. We assume that the total spin of the magnet interacts with a spin bath. We show that depending upon the interaction strengths the molecule can exhibit tunnelling with or without decoherence. We also investigate the case where the spin‐spin interaction is mediated by phonons. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic behaviour of iron nanoparticles passivated by oxidation
Authors: Can Musa Mutlu , Özcan Şadan , Fırat Tezer
Published: January 2006

This study is to understand the effect of oxidation, especially magnetically, on iron nanoparticles. According to generation of the oxidated iron nanoparticles, mechanical alloying technique was used and nanosized magnetite (Fe3O4), maghemite (γ‐Fe2O3) and hematite (α‐Fe2O3) particles were obtained as the resultant samples. The reactance to the thermal treatment was determined by differential thermal analysis and thermogravimetric (DTA‐TG) measurements. X‐ray powder diffractions (XRD) helped to exhibit the structure of the sample by ICDD cards and to determine the size of nanoparticles by using the Scherrer formula. On the other hand, VSM (vibrating sample magnetometer) measurements were determined to understand the magnetic behaviour. Through the transformation of Fe3O4 to other iron‐oxides, two exothermic peaks were observed at around 169.11 °C and 562.61 °C by DTA analysis. Beside of this, the experimental results demonstrate the effects of mechanical milling parameters, atmosphere and lubricant, to the structure and to the size of the resultant particles and the change of magnetic behavior of the iron‐oxide and iron nanoparticles when they approach to superparamagnetic region, especially in single domain region. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin current in spin‐triplet superconducting nanostructures
Authors: Asano Yasuhiro
Published: January 2006

We derive the spin current formula in superconductors on the basis of the mean‐field theory of superconductivity. The obtained formula is applied to mesoscopic p ‐wave superconducting rings. We discuss a possibility of the circulating spin current in p ‐wave superconducting rings at the zero magnetic field. The direction of spin current depends on topological numbers which characterize the spatial configuration of the spin vector of Cooper pairs. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of (Co0.45Fe0.45Zr0.10)x(Al2O3)1–x nanocomposite films applicable as spintronic materials
Authors: Saad A.M. , Fedotov A.K. , Fedotova J.A. , Svito I.A. , Andrievsky B.V. , Kalinin Yu.E. , Fedotova V.V. , Malyutina‐Bronskaya V. , Patryn A.A. , Mazanik A.V. , Sitnikov A.V.
Published: January 2006

The combined use of scanning electron microscopy, Mössbauer spectrometry, X‐ray diffraction and also DC/AC electrical and magnetic characterization techniques allowed this work to elucidate the influence of metal‐to‐dielectric component ration, and effect of oxygen in gas mixture on phase structure and properties of the Co0.45Fe0.45Zr0.10 ferromagnetic nanoparticles in amorphous dielectric Al2O3 matrix. The films of 3–5 µm thickness with compositions of 30 at.% < X < 60 at.% were sputtered on a single substrate from the compound target in the chamber containing either pure Ar or Ar‐O gas mixture. The films sputtered in Ar‐O mixture resulted in partial oxidation of metallic nanoparticles causing the shift of percolation threshold X c to 55 at.% as compared to 45–47 at.% for the samples deposited in pure Ar. Mössbauer studies of the films sputtered in Ar gas have shown that at X < X c metallic nanoparticles were at superparamagnetic state but for X > X c metallic phase showed a ferromagnetic behavior. DC carrier transport at the temperatures of 77–350 K were explained by hopping mechanisms and described by Mott and Shklowski‐Efros laws. That was also confirmed by the relationship power law of Z ′(f ) ∼ f –s (s ≤ 2) for real part of impedance at low temperatures (<120 K) for the samples on dielectric side of MIT. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Off‐resonance Raman spectroscopy of Cd1–xMnxS nanoparticles
Authors: Romčević N. , Kostić R. , Romčević M.
Published: January 2006

Cd1–xMnxS nanoparticles (NPs) with average radius Ro = 2.2 nm have been investigated by Raman scattering measurements. The nanoparticles, synthesized using aqueous solution precipitation, are small enough to show effects due to confinement. The dominant line was at about 300 cm–1 having asymmetric broadening for ω < 300 cm–1. Significant change in intensity for different x and excitation energies was noticed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microstructural study and size control of iron oxide nanoparticles produced by microemulsion technique
Authors: Koutzarova T. , Kolev S. , Ghelev Ch. , Paneva D. , Nedkov I.
Published: January 2006

In this paper we study the possibility to control the size of iron oxide (Fe3O4) nanoparticles by the microemulsion technique. We used a water‐in‐oil reverse microemulsion system with n‐hexadecil trimethylammonium bromide (CTAB) as a cationic surfactant, n‐butanol as a co‐surfactant, n‐hexanol as a continuous oil phase, and aqueous phase. The magnetite nanopowders were synthesized by a single microemulsion technique in which the aqueous phase contains only metal ions (Fe2+ and Fe3+). The particle size of the powders varied in the range of 14–36 nm depending on the preparation conditions. We studied the influence of changing the water/surfactant ratio (W 0 = 5, 10, 15, 20) and the metallic ion (Fe2+ and Fe3+) concentration on the particle size distribution and crystallinity of Fe3O4. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microwave absorption of ferrite powders in a polymer matrix
Authors: Kolev S. , Yanev A. , Nedkov I.
Published: January 2006

The object of this work is to investigate the microwave absorbing properties of nanocomposite bulk samples. As filler we used magnetite with different particle size in a silicone rubber matrix and investigated the influence of the filler concentration and particle size in the polymer matrix on the microwave nonlinearity in a large frequency range (1 ÷ 13 GHz). We found that the intensity and the frequency at the reflection loss minimum depend on the particle size and particle concentration of magnetite in the samples. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature‐induced changes of domain structures in ultrathin magnetic films
Authors: Polyakova T. , Zablotskii V.
Published: January 2006

We describe the thermal‐driven evolution of stripe domain structures in ultrathin magnetic films with perpendicular anisotropy. Taking into account temperature dependencies of the film magnetic parameters we analyze possible temperature dependencies of the domain period. It is shown that the film heating leads to a decrease in the domain period. In soft films thermally assisted domain nucleation could provide a continuous decrease of the domain period while the domain structure passes through equilibrium states. On increasing the temperature of a hard film, the domain structure exists as metastable one adjusting its period by a sequence of jumps towards to equilibrium. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Imaging of inhomogeneous magnetization and currents coupled with anomalous transport properties in manganites
Authors: Tokunaga M. , Song H. , Tokunaga Y. , Tamegai T.
Published: January 2006

Using magneto‐optical imaging technique, real‐space distributions of magnetic fields are visualized in images of a polarized‐light microscope. Application of this technique to crystals of (La1–z Prz )0.7Ca0.3MnO3 (z = 0.7) and Nd0.5Ca0.5Mn1–y Cry O3 (y = 0.03) revealed inhomogeneous magnetization and currents in the phase‐separated states into ferromagnetic metal and antiferromagnetic insulator. Increase of the transport current switches this inhomogeneous current flow to homogeneous one concomitantly with abrupt increase in resistivity. Using magnetic field dependence of this switching phenomenon, operation fields for colossal magnetoresistance effects can be significantly reduced. Empirical relation between the magnitude of bias currents and transition fields is provided. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Equilibrium and metastable nanoscale domains in ultrathin magnets
Authors: Kisielewski M. , Maziewski A. , Polyakova T. , Zablotskii V.
Published: January 2006

We describe equilibrium and nonequilibrium stripe domains in ultrathin magnetic films with uniaxial perpendicular anisotropy. The notion of the domain chemical potential is introduced to analyze metastable domains and their thermal and field evolution. For ultrathin cobalt films the domain period is calculated as a function of the coercivity field. We demonstrate that the period of metastable domains can significantly differ from the period of equilibrium domains. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Different catalysis role of in‐loop and out‐of‐loop waters in assisting HNS/HSN proton transfer isomerizations: Bridging vs. surrounding effect
Authors: Yin Wenjuan , Yan Shihai , Qin Mei , Li Zhiqiang , Bu Yuxiang
Published: January 2006

In this work, a density function theory (DFT) study is presented for the HNS/HSN isomerization assisted by 1–4 water molecules on the singlet state potential energy surface (PES). Two modes are considered to model the catalytic effect of these water molecules: (i) water molecule(s) participate directly in forming a proton transfer loop with HNS/HSN species, and (ii) water molecules are out of loop (referred to as out‐of‐loop waters) to assist the proton transfer. In the first mode, for the monohydration mechanism, the heat of reaction is 21.55 kcal · mol−1 at the B3LYP/6‐311++G** level. The corresponding forward/backward barrier lowerings are obtained as 24.41/24.32 kcal · mol−1 compared with the no‐water‐assisting isomerization barrier T (65.52/43.87 kcal · mol−1). But when adding one water molecule on the HNS, there is another special proton‐transfer isomerization pathway with a transition state 10T′ in which the water is out of the proton transfer loop. The corresponding forward/backward barriers are 65.89/65.89 kcal · mol−1. Clearly, this process is more difficult to follow than the R–T–P process. For the two‐water‐assisting mechanism, the heat of reaction is 19.61 kcal · mol−1, and the forward/backward barriers are 32.27/12.66 kcal · mol−1, decreased by 33.25/31.21 kcal · mol−1 compared with T. For trihydration and tetrahydration, the forward/backward barriers decrease as 32.00/12.60 (30T) and 37.38/17.26 (40T) kcal · mol−1, and the heat of reaction decreases by 19.39 and 19.23 kcal · mol−1, compared with T, respectively. But, when four water molecules are involved in the reactant loop, the corresponding energy aspects increase compared with those of the trihydration. The forward/backward barriers are increased by 5.38 and 4.66 kcal · mol−1 than the trihydration situation. In the second mode, the outer‐sphere water effect from the other water molecules directly H‐bonded to the loop is considered. When one to three water molecules attach to the looped water in one‐water in‐loop‐assisting proton transfer isomerization, their effects on the three energies are small, and the deviations are not more than 3 kcal · mol−1 compared with the original monohydration‐assisting case. When adding one or two water molecules on the dihydration‐assisting mechanism, and increasing one water molecule on the trihydration, the corresponding energies also are not obviously changed. The results indicate that the forward/backward barriers for the three in‐loop water‐assisting case are the lowest, and the surrounding water molecules (out‐of‐loop) yield only a small effect. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Isolation and characterization of promoters suitable for a multidrug‐resistant marker CuYAP1 in the yeast Candida utilis
Authors: Iwakiri Ryo , Noda Yoichi , Adachi Hiroyuki , Yoda Koji
Published: January 2006

The overexpression of CuYAP1 by the CuGAP1 promoter (Pgap) was recently shown to function as a drug‐resistant selection marker for the industrially important yeast Candida utilis. In order to increase the efficiency of selection, we screened for promoters better than Pgap to express CuYAP1. Two restriction fragments, P2‐1‐2 (0.5 kbp) and P2‐33‐2 (1.4 kbp), gave higher cycloheximide resistance, and five‐ to 10‐fold of the transformants were selectable by using these fragments. These promoters were found to be at the 5′ of the ribosomal protein genes, RPL31 and RPL29, respectively. Interestingly, their transcription activity was less than one‐tenth that of Pgap in the absence of cycloheximide. The transcription also increased by the addition of blasticidin S or hygromycin B and heat shock. These novel characteristics will be suitable for an economical marker of the recombinant cell. The DDBJ/EMBL/GenBank Accession Nos. for P2‐1, P2‐33‐2, RPL31 and RPL29 are AB206952, AB206953, AB208646 and AB208647, respectively. Copyright © 2006 John Wiley & Sons, Ltd.
Spsgt1, a new essential gene of Schizosaccharomyces pombe, is involved in carbohydrate metabolism
Authors: Kainou Tomohiro , Shinzato Tomoko , Sasaki Kentaro , Mitsui Youji , Giga‐Hama Yuko , Kumagai Hiromichi , Uemura Hiroshi
Published: January 2006

hSGT1 (human suppressor of Gcr two) was isolated as a suppressor gene of the gcr2 mutation. Since Gcr2p is a key regulatory factor of glycolytic gene expression in Saccharomyces cerevisiae, hSGT1 is a candidate for a novel human transcription factor involved in carbohydrate metabolism. SGT1 appears to be conserved from Schizosaccharomyces pombe to human but not present in S. cerevisiae. To further study its function, we cloned the hSgt1p orthologue of Sz. pombe (Spsgt1) from Sz. pombe genomic DNA. Overall identity and similarity between SpSgt1p and hSgt1p are 24% and 37%, respectively. Disruption of Spsgt1 showed that Spsgt1 is essential for growth and, using a construct which conditionally expresses sgt1, which with low level expression growth was severely affected on glucose but normal on non‐fermentable carbon sources. DNA microarray analyses showed that the transcription of many genes involved in carbohydrate metabolism and amino acid metabolism were upregulated in the mutant, suggesting that SpSgt1p may be involved in the regulation of carbohydrate metabolism. Furthermore, a GFP fusion of SpSgt1p was localized to the nucleus, fitting with the possibility of SpSgt1p as a transcription factor. Copyright © 2006 John Wiley & Sons, Ltd.