bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel porous Ti6Al4V: Characterization and cell attachment
Authors: Li J. P. , Li S. H. , Van Blitterswijk C. A. , de Groot K.
Published: March 2005

For the first time, a highly porous strong Ti6Al4V was produced by using a “polymeric sponge replication” method. A polymeric sponge, impregnated with a Ti6Al4V slurry prepared from Ti6Al4V powders and binders, was subjected to drying and pyrolyzing to remove the polymeric sponge and binders. After sintering at a high temperature and under high vacuum, a porous Ti6Al4V was produced. Optical microscopical observation, environmental scanning electron microscopy observation (with energy‐dispersive micro X‐ray analysis), mechanical tests, and metallurgical analyses were performed on the obtained porous Ti6Al4V with regard to the porous structure (both macropores and micropores), mechanical properties, chemical composition, phase compositions, and cell attachment behavior. The porous Ti6Al4V made by this method had a three‐dimensional trabecular porous structure with interconnected pores mainly ranging from 400 to 700 μm and a total porosity of about 90%. The compressive strength was 10.3 ± 3.3 MPa and the elastic constant 0.8 ± 0.3 GPa. MC3T3‐E1 cells attached and spread well in the inner surface of pores. Being similar to cancellous bone with regard to both interconnected porous structure and mechanical properties, the resulting porous Ti6Al4V is expected to be a promising biomaterial for biomedical applications. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 73A: 223–233, 2005
Activation of Wnt/β‐catenin/Tcf signaling in mouse skin carcinogenesis
Authors: Bhatia Neehar , Spiegelman Vladimir S.
Published: March 2005

Although Wnt/β‐catenin/Tcf signaling pathway has been shown to be an important factor in the development of many malignancies including colorectal, ovarian, prostate, and many other cancers, little is known about its role in non‐melanoma skin cancers. Here, we report the first evidence that β‐catenin/Tcf signaling pathway is constitutively activated in non‐melanocytic skin tumors induced by two stage chemical carcinogenesis protocol. Mouse skin tumors showed cytoplasmic and nuclear accumulation of β‐catenin, and upregulation of β‐catenin/Tcf target genes (c‐myc and c‐jun). We found high levels of skin‐expressed Wnt proteins (Wnt 3, 4, and 10b) in different parts of the tumors, likely representing key upstream events in β‐catenin/Tcf activation during mouse skin carcinogenesis. Inhibition of β‐catenin/Tcf signaling by ectopic expression of dominant negative Tcf4 resulted in significant inhibition of growth in squamous cell carcinoma cells. A role of the constitutive activation of β‐catenin/Tcf signaling in skin carcinogenesis is discussed. © 2005 Wiley‐Liss, Inc.
Defect states in Czochalski p‐type silicon: the role of oxygen and dislocations
Authors: Castaldini A. , Cavalcoli D. , Cavallini A. , Pizzini S.
Published: March 2005

This contribution reports the study, by junction spectroscopies, of electronic states induced by thermal and deformation treatments in p‐type Si. In order to understand the role that oxygen precipitation, metallic contamination and plastic deformation play on the defect states, several sets of Cz (Czochalski) and Fz (Float‐zone) Si samples and different material treatments were investigated. The electronic states were also compared with optical transitions obtained by photoluminescence analyses carried out on the same sample sets. These defect states could thus be microscopically identified with specific defect types. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cation distribution, hyperfine parameters and conduction mechanism in the ferrimagnetic system Cu0.5Co0.5GaxFe2–xO4
Authors: Ata‐Allah S. S. , Kaiser M.
Published: March 2005

Compositions having the chemical formula Cu0.5Co0.5GaxFe2–xO4with (0.0 ≤x≤ 0.5) have been prepared by the usual ceramic processing from high‐purity oxides. X‐ray diffraction measurements are used for analyzing the composition, lattice parameter, density, porosity and grain size of these compounds. The area ratio of Fe3+at the tetrahedral A‐ and octahedral B‐sites deduced from the spectral analysis of Mössbauer measurements on the present spinel system gives evidence that Ga replaces Fe at A‐site in the range 0.0  0.3), it replaces Fe at B‐site. This change in the site preference reflects an abrupt change in the hyperfine parameters with Ga content atx> 0.3. The electrical measurements as a function of temperature and frequency on these materials revealed semiconducting behavior. These results show a significant increase in the frequency dependence of conductivity as Ga content increases. Variation of the universal exponentswith temperature indicates the presence of small‐polaron (SP) hopping mechanism at low Ga content. As Ga substitution progressed, the overlap large polaron (OLP) becomes the predominant hopping mechanism in these compounds. The determined transition temperatureTCof these samples is found to decrease linearly with increasing Ga contentx. The results obtained in this study are interpreted in light of the cation–cation and cation–anion–cation interactions in the spinel structure. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phospholipase Cγ in distinct regions of the ventral tegmental area differentially regulates morphine‐induced locomotor activity
Authors: Bolaños Carlos A. , Neve Rachael L. , Nestler Eric J.
Published: March 2005

Neurotrophic factors and the signaling pathways they activate play a role in mediating long‐term molecular, cellular, and behavioral adaptations associated with drug addiction. Here we mimicked the biological response of phospholipase C‐γ (PLCγ) induction in the ventral tegmental area (VTA) observed after chronic morphine using viral‐mediated gene transfer. Using a behavioral sensitization paradigm, we demonstrate that microinjections of PLCγ1 into distinct (rostral vs. caudal) regions of the VTA result in differential locomotor responses to morphine. Synapse 56:166–169, 2005. © 2005 Wiley‐Liss, Inc.
Continuous opioid agonist treatment dose‐dependently regulates μ‐opioid receptors and dynamin‐2 in mouse spinal cord
Authors: Zhang Qiuyu , Purohit Vishal , Yoburn Byron C.
Published: March 2005

Continuous opioid agonist treatment produces tolerance and in some cases μ opioid receptor (μOR) down‐regulation. Previous studies indicate that down‐regulation of μOR is more likely with high‐efficacy opioid agonists (e.g., etorphine), whereas lower efficacy agonists (e.g., morphine) do not regulate μOR density. It has been suggested that μOR down‐regulation may depend upon increases in Dynamin‐2 (DYN‐2) proteins. Therefore, the present study examined the effect of various infusion doses of etorphine on μOR density, DYN‐2 protein, and DYN‐2 mRNA abundance in mouse spinal cord. Mice were implanted sc with an osmotic pump that infused etorphine (50–250 μg/kg/day). Controls were implanted with inert placebo pellets. At the end of 7 days, mice were sacrificed, spinal cord removed and processed for radioligand binding, quantitative Western blotting, or RT‐PCR assay. Results indicate that etorphine induced dose‐dependent regulation of μOR density, DYN‐2 proteins, and mRNA abundance in mouse spinal cord. Higher infusion doses significantly down‐regulated μOR density, increased DYN‐2 protein abundance, and decreased DYN‐2 mRNA. Analysis of these results indicated a significant correlation between μOR down‐regulation and DYN‐2 abundance in mouse spinal cord. Taken together, μOR regulation may depend on changes in DYN‐2 abundance induced by high‐efficacy opioid agonists in mouse spinal cord. Synapse 56:123–128, 2005. © 2005 Wiley‐Liss, Inc.
Increase of GAP‐43 in the rat cerebellum following unilateral striatal 6‐OHDA lesion
Authors: Perović Milka , Mladenović Aleksandra , Rakić Ljubisav , Ruždijić Sabera , Kanazir Selma
Published: March 2005

In order to further characterize synaptic alterations following a severe lesion of the nigrostriatal system, the expression of synaptic marker proteins, synaptophysin and growth‐associated protein‐43 (GAP‐43), was examined in various brain regions of 6‐hydroxydopamine (6‐OHDA)‐treated rats, an animal model of Parkinson's disease. Unilateral nigrostriatal lesioning induced an increase in synaptophysin protein levels by 68% and 106% in the sensorimotor cortex and striatum, respectively, while changes in the level of GAP‐43 were not observed. In contrast, 6‐OHDA induced a 73% increase in the level of GAP‐43 protein in the cerebellum. This increase was also confirmed with immunohistochemistry. The level of synaptophysin in the cerebellum remained unchanged in response to the lesion. These results suggest that a neurotoxic lesion of the nigrostriatal pathway differentially affects the expression of the two synaptic proteins and that plasticity‐related changes in this model are not solely restricted to the nigrostriatal system. In addition, these results provide further evidence of the involvement of the cerebellum in the late response to a 6‐OHDA lesion. Synapse 56:170–174, 2005. © 2005 Wiley‐Liss, Inc.
Abnormal auditory N400 in a case of zolpidem dependence, during a working memory test
Authors: Liappas Ioannis A. , Papageorgiou Charalabos C. , Rabavilas Andreas D.
Published: March 2005

Zolpidem is a GABA (A) agonist, which is indicated for the short-term management of insomnia. Recent research provide evidence suggesting that zolpidem produces spatial working memory (WM) deficits and dependence; however, the underlying mechanisms of these effects are unknown. Since the auditory N400 component of event-related potentials (ERPS) is considered as an index of memory use of context processing, the present study focused on N400 waveform of ERPs elicited during a WM task in a case suffering from zolpidem dependence. The patterns of N400 waveform of this case were compared to the patterns obtained from healthy controls. This comparison revealed that zolpidem dependence is accompanied by reduced amplitudes located at posterior brain areas and diffuse prolongation of N400. These findings may indicate that zolpidem dependence manifests alterations with regard to the memory use of context processing, involving or affecting a wide-ranging network of the brain's structures.
Media consumption and desire for social distance towards people with schizophrenia
Authors: Angermeyer M.C. , Dietrich S. , Pott D. , Matschinger H.
Published: March 2005

There is ample evidence for a distorted presentation of the mentally ill in the media. However, only little is known about its impact on attitudes towards people with mental disorders. Therefore, we investigated the relationship between watching TV and reading the newspaper on the one hand, and the desire for social distance towards people with schizophrenia on the other. In 2001, a representative population survey was conducted in Germany, using a fully structured personal interview. We found that the desire for social distance towards people with schizophrenia increases almost continuously with the amount of TV consumption. The association between reading the newspaper and social distance is less pronounced and depends on the type of newspaper people read. Since, obviously, there is a relationship between media consumption and attitudes towards people with schizophrenia, inaccurate and one-sided messages about mental disorders should be replaced by accurate and more balanced messages.
Thermolabile phenotype of carnitine palmitoyltransferase II variations as a predisposing factor for influenza‐associated encephalopathy
Authors: Chen Y. , Mizuguchi H. , Yao D. , Ide M. , Kuroda Y. , Shigematsu Y. , Yamaguchi S. , Yamaguchi M. , Kinoshita M. , Kido H.
Published: March 2005

To assess the etiology of influenza‐associated encephalopathy (IAE), a surveillance effort was conducted during 2000–2003 in South‐West Japan. All fatal and handicapped patients except one (4/34 patients) exhibited a disorder of mitochondrial β‐oxidation evoked by the inactivated carnitine palmitoyltransferase II (CPT II) with transiently elevated serum acylcarnitine ratios (C16:0
+ C18:1)/C2 >
0.09 during high‐grade fever. Analyses of genotypes and allele compositions of CPT II revealed a thermolabile phenotype of compound heterozygotes for [1055T >
G/F352C] and [1102G >
A/V368I], which shows a higher frequency in IAE patients than healthy volunteers (P
< 0.025). The thermolabile phenotype of CPT II variations may be a principal genetic background of IAE in Japanese.
Xestospongin B, a competitive inhibitor of IP3‐mediated Ca2+ signalling in cultured rat myotubes, isolated myonuclei, and neuroblastoma (NG108‐15) cells
Authors: Jaimovich Enrique , Mattei César , Liberona José Luis , Cardenas Cesar , Estrada Manuel , Barbier Julien , Debitus Cécile , Laurent Dominique , Molgó Jordi
Published: March 2005

Xestospongin B, a macrocyclic bis‐1‐oxaquinolizidine alkaloid extracted from the marine sponge Xestospongia exigua, was highly purified and tested for its ability to block inositol 1,4,5‐trisphosphate (IP3)‐induced Ca2+ release. In a concentration‐dependent manner xestospongin B displaced [3H]IP3 from both rat cerebellar membranes and rat skeletal myotube homogenates with an EC50 of 44.6 ± 1.1 μM and 27.4 ± 1.1 μM, respectively. Xestospongin B, depending on the dose, suppressed bradykinin‐induced Ca2+ signals in neuroblastoma (NG108‐15) cells, and also selectively blocked the slow intracellular Ca2+ signal induced by membrane depolarization with high external K+ (47 mM) in rat skeletal myotubes. This slow Ca2+ signal is unrelated to muscle contraction, and involves IP3 receptors. In highly purified isolated nuclei from rat skeletal myotubes, Xestospongin B reduced, or suppressed IP3‐induced Ca2+ oscillations with an EC50
= 18.9 ± 1.35 μM. In rat myotubes exposed to a Ca2+‐free medium, Xestospongin B neither depleted sarcoplasmic reticulum Ca2+ stores, nor modified thapsigargin action and did not affect capacitative Ca2+ entry after thapsigargin‐induced depletion of Ca2+ stores. Ca2+‐ATPase activity measured in skeletal myotube homogenates remained unaffected by Xestospongin B. It is concluded that xestospongin B is an effective cell‐permeant, competitive inhibitor of IP3 receptors in cultured rat myotubes, isolated myonuclei, and neuroblastoma (NG108‐15) cells.
Exploring the effects of fishing on fish assemblages using Abundance Biomass Comparison (ABC) curves
Authors: Yemane Dawit , Field John G. , Leslie Rob W.
Published: March 2005

The possible effect of fishing on dominance patterns in the South African south coast demersal trawl fishery is assessed using Abundance Biomass Comparison (ABC) curves for the period 1986–2003. The ABC method compares the ranked distribution of abundance among species against the similar distribution of biomass among species. The temporal pattern in the ABC curves and the W-statistic for two depth groups (<100 m and 101–200 m), and for the whole area combined, shows a gradient of change in the demersal assemblages from neutral (W ≥ 0) towards negative (W < 0), suggesting a disturbed or stressed condition. This corresponds to the onset of longline fishing effort in 1994, still ongoing in 2003, superimposed upon declining trawl effort in the same region. The ABC method shows promise as a guide for assessing the effects of fishing on fish communities, being based on established r- and k-selection theory. More modelling and comparative work is needed to establish acceptable ranges for the W-statistic, and their application in an ecosystem approach to fisheries management.
Negative Priming with Masked Distractor-Only Prime Trials
Authors: Frings Christian , Wentura Dirk
Published: March 2005

Abstract. The literature yields inconsistent evidence for negative priming (NP) following masked distractor-only prime trials. We contrast two different hypotheses on the inconsistent findings: one - which is most compatible with the temporal discrimination theory - that relates the sign of priming effects to the absence vs. presence of prime awareness and one - which is most compatible with the inhibition and episodic retrieval accounts - that relates the sign of priming effects to the prime event being categorized as a to-be-attended vs. to-be-ignored event. In two experiments, it turned out that participants’ awareness of the masked stimuli caused the different results (with participants being not aware of the primes showing NP), whereas the factor prime color = probe target color vs. prime color = probe distractor color (i.e., the prime contains the to-be-attended vs. the to-be-ignored signal) did not moderate NP. These findings are discussed with regard to theories of negative priming and the debate on conscious vs. unconscious perception.
Headache Associated with Dialysis: the International Headache Society Criteria Revisited
Authors: Antoniazzi AL , Bigal ME , Bordini CA , Speciali JG
Published: March 2005

The International Headache Society (IHS) criteria for headache related to haemo-dialysis consider that the headaches must begin during haemodialysis and terminate within 24 h. Twenty-eight patients whose headaches started by the time they entered the dialysis programme were prospectively studied. We were not able to classify eight patients that presented the headaches between the sessions. Despite the small number of patients in our study being too low to provide a basis for change in the IHS classification, it serves as an observational report demonstrating possible varieties of headache related to haemodialysis.
Blocking Characteristics of hERG, hNav1.5, and hKvLQT1/hminK after Administration of the Novel Anti‐Arrhythmic Compound AZD7009
Authors: PERSSON FRIDA , CARLSSON LEIF , DUKER GÖRAN , JACOBSON INGEMAR
Published: March 2005

Introduction: AZD7009 is a novel anti‐arrhythmic compound under development for short‐ and long‐term management of atrial fibrillation and flutter. Electrophysiological studies in animals have shown high anti‐arrhythmic efficacy, predominant action on atrial electrophysiology, and low proarrhythmic activity. The main aim of this study was to characterize the blocking effects of AZD7009 on the human ether‐a‐go‐go‐related gene (hERG), the hNav1.5, and the hKvLQT1/hminK currents.

Methods and Results: hERG, hKvLQT1/hminK, and hNav1.5 were expressed in CHO K1 cells. Currents were measured using the whole‐cell configuration of the voltage‐clamp technique. AZD7009 inhibited the hERG current with an IC50 of 0.6 ± 0.07 μM (n = 6). AZD7009 1 μM hyperpolarized the potential for half‐maximal activation from −8.2 ± 0.1 mV to −18.0 ± 0.6 mV (P < 0.001, n = 14) and induced pre‐pulse potentiation at potentials near the activation threshold. The hNav1.5 current was blocked with an IC50 of 4.3 ± 1.20 μM at 10 Hz (n = 6) and block developed use‐dependently. Recovery from use‐dependent block was slow, τ= 131 seconds. AZD7009 inhibited the hKvLQT1/hminK current only at high concentrations (IC50= 193 ± 20 μM, n = 6).

Conclusion: AZD7009 inhibits both the hERG and the hNav1.5 current, and it is most likely this combined current block that underlies the prolongation of the refractoriness and the low proarrhythmic activity demonstrated in animals in vivo.
Gender Differences in Autonomic Modulation of Ventricular Repolarization in Humans
Authors: NAKAGAWA MIKIKO , OOIE TATSUHIKO , OU BAIQING , ICHINOSE MASASHI , TAKAHASHI NAOHIKO , HARA MASAHIDE , YONEMOCHI HIDETOSHI , SAIKAWA TETSUNORI
Published: March 2005

Background: Gender differences in the incidence of ventricular arrhythmias have been reported and torsades de pointes associated with long QT syndrome are more common in women than men. Although increased sympathetic tone has an important role in vulnerability to arrhythmia, little is currently known regarding gender differences in the dynamic electrophysiological response to sympathetic stimulation. Therefore, we investigated whether there is a gender difference in humans with respect to the dynamic response of ventricular repolarization to β‐adrenergic stimulation and to autonomic blockade.

Methods: Twelve‐lead ECGs were continuously recorded during isoproterenol infusion (protocol 1) and autonomic blockade with propranolol and atropine infusion (protocol 2) in 24 healthy volunteers (12 men, 23 ± 2 years; 12 women, 23 ± 5 years). QT (QTc) intervals were measured at the baseline and at a heart rate of 75, 100, and 120 beats/min.

Results: (1) The morphology of the T wave dynamically and transiently changed to bifid or biphasic during the acute phase of isoproterenol infusion. The incidence of these morphologic changes was higher in women than men (P < 0.05). (2) The QTc interval was initially prolonged and then shortened in both men and women during isoproterenol administration. However, QTc prolongation was significantly greater in women (0.44 ± 0.02 to 0.55 ± 0.03 sec) than men (0.42 ± 0.03 to 0.51 ± 0.04 sec; P < 0.05). (3) The QTc interval was significantly prolonged under autonomic blockade and the intrinsic QTc interval was longer in women than men (P < 0.05).

Conclusion: While sympathetic stimulation and autonomic blockade modulated the dynamics of ventricular repolarization in both sexes, it was more pronounced in women. This gender difference may partially account for the susceptibility of women to arrhythmogenesis.
Novel Imaging Techniques of the Esophagus Enhancing Safety of Left Atrial Ablation
Authors: POLLAK SCOTT J. , MONIR GEORGE , CHERNOBY MICHAEL S. , ELENBERGER CHARLOTTE D.
Published: March 2005

This report describes different imaging techniques of the esophagus in four patients during radiofrequency catheter ablation of atrial fibrillation in the left atrium. A novel use of a mixture of barium cream and gadolinium diglutamate allowed esophageal imaging during magnetic resonance angiography of the left atrium and pulmonary veins. Barium cream used during computer tomography angiographic imaging of the left atrium and pulmonary veins allowed esophageal imaging. The esophagus was also imaged with an electroanatomic mapping system. Esophageal and left atrial imaging helped to avoid catheter ablation in left atrial tissue overlapping the esophagus.
Open‐State Unblock Characterizes Acute Inhibition of IKs Potassium Current by Amiodarone in Guinea Pig Ventricular Myocytes
Authors: ZANKOV DIMITAR P. , DING WEI‐GUANG , MATSUURA HIROSHI , HORIE MINORU
Published: March 2005

Introduction: The aim of the present study was to investigate the acute action of amiodarone on the slow component of delayed rectifier K+ current (IKs) under basal conditions and during β‐adrenoceptor stimulation in guinea pig ventricular myocytes.

Methods and Results: Using the whole‐cell patch‐clamp method, IKs was evoked by depolarizing voltage‐clamp steps, during superfusion with the Na+‐, K+‐, and Ca2+‐free solution supplemented with 0.4 μM nisoldipine and 5 μM E‐4031. The acute effect of amiodarone was evaluated, within ∼10 minutes after starting the bath application, by the amplitude of deactivating tail currents at –50 mV. Amiodarone concentration dependently blocked IKs and exerted a more potent effect on IKs when activated by shorter pulse durations; the degree of block by 30 μM amiodarone on IKs activated by 200 ms, 500 ms, and 2000 ms depolarizing pulses to +30 mV was 55.9 ± 5.8%, 38.6 ± 6.0%, and 27.1 ± 4.0% (n = 5 each), respectively. An envelope of tails test conducted at +10, +30, and +60 mV demonstrated that the degree of IKs block by amiodarone was gradually attenuated during membrane depolarization, which can be described by a monoexponential function, thus supporting the presence of open channel unblock. Amiodarone also blocked IKs maximally stimulated by 1 μM isoprenaline, to an extent similar to control, when IKs was activated by pulse durations of ≤2000 ms.

Conclusion: We propose that amiodarone acutely blocks native IKs with characteristics associated with open channel unblock, and that the protein kinase A‐mediated phosphorylation of channel proteins only minimally affects the amiodarone block.
Saline‐Irrigated Radiofrequency Ablation Electrode with External Cooling
Authors: WITTKAMPF FRED H.M. , NAKAGAWA HIROSHI , FORESTI SARAH , AOYAMA HIROSHI , JACKMAN WARREN M.
Published: March 2005

Introduction: Open flush, irrigated ablation electrodes may improve the safety of radiofrequency catheter ablation by preventing protein aggregation and coagulum formation. This is particularly important in left‐sided procedures like catheter ablation of atrial fibrillation. Electrode cooling and the inherent loss of temperature feedback, however, grossly reduce the ability to monitor tissue heating. Intimate contact may not be recognized and the delivery of nominal RF power levels may then lead to excessive tissue heating, steam explosions, and even tamponade.

Methods and Results: Standard, open flush, irrigated catheters (Sprinklr, Medtronic Inc, Minneapolis, MN) were modified by thermally insulating the irrigation channels inside the ablation electrode. Using the thigh muscle preparation, multiple lesions were created with standard and modified catheters using 60 s, 20–50 Watt applications and a constant saline flush rate of 20 cc/min. A total of 57 lesions were created on five thigh muscles of three dogs. Lesion dimensions were not significantly different between both types of catheter, but the maximum electrode temperature rise during ablation was significantly higher with the modified catheter. Insulation of the irrigation channels improved the correlation coefficient between maximum electrode temperature rise and lesion volume from 0.38 (ns) to 0.62 (P < 0.001).

Conclusion: Thermal insulation of the irrigation channels facilitates temperature feedback during radiofrequency ablation and controllability of lesion formation.
Modeling of beryllium deposition from a beryllium-seeded deuterium plasma
Authors: Schmid K. , Baldwin M. , Doerner R.
Published: March 2005

This paper is concerned with modeling the formation of beryllium (Be) layers deposited from a Be-seeded deuterium (D) plasma. In recent experiments at the PISCES-B divertor simulator [Y. Hirooka et al., J. Vac. Sci. Technol. A 8, 1790 (1990)] at UC-San Diego, C targets biased at −50V were exposed to a Be-seeded D plasma in the temperature range from 500to1280K and Be plasma concentrations in the range from 0.01% to 0.4%. It was found in [K. Schmid, M. Baldwin, R. Doetner, and A. Wiltner, Nucl. Fusion 44, 815 (2004)] that even at these low Be concentrations the C samples become covered with a shielding Be layer which almost eliminates chemical and physical erosions of the C sample in the observed target temperature range. Three different approaches were used to model these experimental results: the well-established binary collision Monte Carlo code TRIDYN [W. Möller, W. E. Und, and J. P. Biersack, Comput. Phys. Commun. 51, 355 (1988)], the recently developed plasma surface interaction code GWAR, and analytical expressions were compared. The paper explains the details of the developed models and how their results compare to the experiment.
Characterization of a silicon–germanium quantum dot structure at 4.2K and 40mK
Authors: Gandolfo D. S. , Williams D. A. , Qin H.
Published: March 2005

Characterization of a trench-isolated double quantum dot fabricated from silicon germanium has been carried out via low-temperature electron transport measurements. Coulomb oscillations have been observed, and the mean energy required to add a single electron to the quantum dot was 3.9meV at 4.2K and 2.9meV at 40mK. The total capacitance of the double-quantum dot increased from 40aF at 4.2K to 55aF at 40mK.
Quantitative characterization of inertial confinement fusion capsules using phase contrast enhanced x-ray imaging
Authors: Kozioziemski B. J. , Koch J. A. , Barty A. , Martz H. E. , Lee Wah-Keat , Fezzaa Kamel
Published: March 2005

Current designs for inertial confinement fusion capsules for the National Ignition Facility consist of a solid deuterium–tritium (D–T) fuel layer inside of a copper doped beryllium, Be(Cu), shell. Phase contrast enhanced x-ray imaging is shown to render the D–T layer visible inside the Be(Cu) shell. Phase contrast imaging is experimentally demonstrated for several surrogate capsules and validates computational models. Polyimide and low density divinyl benzene foam shells were imaged at the Advanced Photon Source synchrotron. The surrogates demonstrate that phase contrast enhanced imaging provides a method to characterize surfaces when absorption imaging cannot be used. Our computational models demonstrate that a rough surface can be accurately characterized using phase contrast enhanced x-ray images.
Electron bombardment induced enhancement of luminescence from ZnCdMgSe quantum well light emitting diodes
Authors: Nikiforov A. Yu. , Cargill G. S. , Guo S. P. , Tamargo M. C.
Published: March 2005

Electron bombardment enhancement of luminescence from ZnCdMgSe quantum well (QW) light emitting diodes has been studied by time-resolved and bias- and temperature-dependent cathodoluminescence (CL) spectroscopy and mapping. Effects of electron bombardment are seen as bright regions in CL images. The enhancement of CL intensity decays with time after electron bombardment for tens and hundreds of hours, and the rate of decay is faster for higher temperatures in the range studied, 20–200°C. We propose that the enhancement of QW CL intensity results from buildup of internal fields due to persistent charge trapping at pre-existing or electron bombardment created defects. A simple trapping-detrapping model involving two types of traps with different activation energies reproduces most aspects of the observed time and temperature dependence of decay of the luminescence enhancement.
Defect reduction in (11¯00) m-plane gallium nitride via lateral epitaxial overgrowth by hydride vapor phase epitaxy
Authors: Haskell B. A. , Baker T. J. , McLaurin M. B. , Wu F. , Fini P. T. , DenBaars S. P. , Speck J. S. , Nakamura Shuji
Published: March 2005

This letter reports on extended defect density reduction in m-plane (11¯00) GaN films achieved via lateral epitaxial overgrowth (LEO) by hydride vapor phase epitaxy. Several dielectric mask patterns were used to produce 10 to 100 μm-thick, partially and fully coalesced nonpolar GaN films. X-ray rocking curves indicated the films were free of wing tilt. Transmission electron microscopy showed that basal plane stacking fault (SF) and threading dislocation (TD) densities decreased from 105cm−1 and 109cm−2, respectively, less than 3×103cm−1 and ∼5×106cm−2, respectively, in the Ga-face (0001) wing of the LEO films. SFs persisted in ⟨0001⟩-oriented stripe LEO films, though TD reduction was observed in the windows and wings. Band-edge cathodoluminescence intensity increased 2 to 5 times in the wings compared to the windows depending on the stripe orientation. SFs in the low TD density wings of ⟨0001⟩-stripe films did not appear to act as nonradiative recombination centers.
Effect of misfit strain and external electric field on dielectric behavior of epitaxial SrTiO3 thin films
Authors: Gao Yan-Hong , Cao Hai-Xia , Jiang Qing
Published: March 2005

Based on a Landau-Ginsburg-Devonshire (LD)-type phenomenological model, the effect of misfit strain and externally applied electric field on dielectric properties of epitaxially single-domain SrTiO3 thin films is investigated by taking into account the existence of two coupled instabilities (ferroelectric and antiferrodistortive). The epitaxy-induced strain may enable the phase of films transform to ferroelectric phase that is impossible for bulk “quantum paraelectric.” At low temperature, the critical tensile strain is in favor of relative high dielectric constant along [100] direction, while the critical compressive strain is useful to that of [001] direction. A high tunability may be obtained by adjusting misfit strain, especially in the vicinity of a structural phase transition. It is also shown that the electric field is facile to induce ferroelectricity in the case of purely structural orthorhombic (SO) phase or tetragonal (ST) phase under reasonable misfit strains when the external electric field is parallel with the order parameter qi. The structural order parameter induced may explain the “weak peak anomaly” phenomenon. Furthermore, the electric field dependence of dielectric responses of different structure phases is also discussed with various misfit strains. Our theoretical results are in good agreement with the experimental ones reported in the literature.
Three-terminal organic memory devices
Authors: He Jun , Ma Liping , Wu Jianhua , Yang Yang
Published: March 2005

An organic electrical bistable device (OBD) has been reported previously, which has an organic∕metal-nanocluster∕organic structure sandwiched between a top and bottom electrode [L. P. Ma, J. Liu, and Y. Yang, Appl. Phys. Lett. 80, 2997 (2002)]. This device can be switched between a low- (OFF) and a high- (ON) conductivity state by external bias. In this article, we report a three-terminal organic memory device, which is realized by wiring out the metal-nanocluster layer of the OBD as the middle electrode. The ON and OFF states of the device can be read out by measuring the potential of the middle electrode. By controlling the interface formation of the device, a three-terminal OBD with a potential change on the middle electrode of more than three orders in magnitude between the OFF state and ON state (from 0.2mVto0.77V) is achieved. By wiring out the middle electrode, the three-terminal OBD can also be considered as two 2-terminal devices stacked together. By proper interface engineering (to be discussed in detail in the text), we found that both the top and bottom devices show electrical bistability and memory effect. This can double the data storage density of the memory device. Details of the device mechanism are provided.
Numerical simulations of interfacial instabilities on a rotating miscible magnetic droplet with effects of Korteweg stresses
Authors: Chen Ching-Yao , Wu H.-J.
Published: March 2005

Interfacial instability of a miscible magnetic droplet in a rotating Hele-Shaw cell is simulated numerically. The influence of magnetic strengths, the Korteweg stresses, and their coupled effects are first discussed qualitatively by fingering patterns and streamlines. Quantitative measurements are evaluated by interfacial length L, number of fingers n, and diameter of gyration Dg. The results confirm with coupling rotational effects more vigorous fingering instability occurs on stronger magnetic strengths and less effective surface tensions (Korteweg stresses). Without the effects of Korteweg stresses, significant nonlinear fingering merges occur which lead to reduction in fingering number, early decay of interfacial length and reversed plane trajectories. Before the occurrence of fingering merges, monotonic growths of interfacial lengths, constant fingering numbers, and nearly linear pattern trajectories are observed. If the significant Korteweg stresses are taken into account, the nonlinear merge is prevented and the features of fingering patterns resemble the immiscible situations remarkably. The fingering behavior can be approximated by a master line of dL∕dDg≈0.386n+0.13 within the linear fingering region.
Large-area traveling-wave photonic mixers for increased continuous terahertz power
Authors: Michael E. A. , Vowinkel B. , Schieder R. , Mikulics M. , Marso M. , Kordoš P.
Published: March 2005

A large-aperture design for terahertz traveling-wave photomixers, continuously pumped free space by two detuned diode lasers, is proposed and experimentally verified for devices based on low-temperature-grown GaAs (LT-GaAs). It combines the advantages of conventional interdigitated small-area structures and traveling-wave devices. An output power of 1 μW at the mixing frequency of 1 THz was measured in initial testing, which meets local oscillator power requirements for superconducting heterodyne mixer devices.
Transparent Nd and (Nd, Yb)-doped Sc2O3 ceramics as potential new laser materials
Authors: Lupei V. , Lupei A. , Ikesue A.
Published: March 2005

Highly transparent Sc2O3 ceramics with uniform doping up to 0.5at.% Nd and with (Nd, Yb) codoping are reported. The spectroscopic and emission decay properties of Nd:Sc2O3 ceramics are similar to those of single crystals. Highly efficient Nd-to-Yb energy transfer is observed in the codoped ceramics. It is inferred that these materials have potential for construction of Nd or Nd-sensitised-Yb lasers.
A survey of homozygous deletions in human cancer genomes
Authors: Cox Charles , Bignell Graham , Greenman Chris , Stabenau Arne , Warren William , Stephens Philip , Davies Helen , Watt Stephen , Teague Jon , Edkins Sara , Birney Ewan , Easton Douglas F. , Wooster Richard , Futreal P. Andrew , Stratton Michael R.
Published: March 2005

Homozygous deletions of recessive cancer genes and fragile sites are known to occur in human cancers. We identified 281 homozygous deletions in 636 cancer cell lines. Of these deletions, 86 were homozygous deletions of known recessive cancer genes, 17 were of sequenced common fragile sites, and 178 were in genomic regions that do not overlap known recessive oncogenes or fragile sites (“unexplained” homozygous deletions). Some cancer cell lines have multiple homozygous deletions whereas others have none, suggesting intrinsic variation in the tendency to develop this type of genetic abnormality (
P
< 0.001). The 178 unexplained homozygous deletions clustered into 131 genomic regions, 27 of which exhibit homozygous deletions in more than one cancer cell line. This degree of clustering indicates that the genomic positions of the unexplained homozygous deletions are not randomly determined (
P
< 0.001). Many homozygous deletions, including those that are in multiple clusters, do not overlap known genes and appear to be in intergenic DNA. Therefore, to elucidate further the pathogenesis of homozygous deletions in cancer, we investigated the genome landscape within unexplained homozygous deletions. The gene count within homozygous deletions is low compared with the rest of the genome. There are also fewer short interspersed nuclear elements (SINEs), long interspersed nuclear elements (LINEs), and low-copy-number repeats (LCRs). However, DNA within homozygous deletions has higher flexibility. These features may signal the presence of currently unrecognized zones of susceptibility to DNA rearrangement. They may also reflect a tendency to reduce the adverse effects of homozygous deletions by minimizing the number of genes removed.
The interaction between σ
70
and the β-flap of
Escherichia coli
RNA polymerase inhibits extension of nascent RNA during early elongation
Authors: Nickels Bryce E. , Garrity Sean J. , Mekler Vladimir , Minakhin Leonid , Severinov Konstantin , Ebright Richard H. , Hochschild Ann
Published: March 2005

The σ-subunit of bacterial RNA polymerase (RNAP) is required for promoter-specific transcription initiation. This function depends on specific intersubunit interactions that occur when σ associates with the RNAP core enzyme to form RNAP holoenzyme. Among these interactions, that between conserved region 4 of σ and the flap domain of the RNAP β-subunit (β-flap) is critical for recognition of the major class of bacterial promoters. Here, we describe the isolation of amino acid substitutions in region 4 of
Escherichia coli
σ
70
that have specific effects on the σ
70
region 4/β-flap interaction, either weakening or strengthening it. Using these σ
70
mutants, we demonstrate that the σ region 4/β-flap interaction also can affect events occurring downstream of transcription initiation during early elongation. Specifically, our results provide support for a structure-based proposal that, when bound to the β-flap, σ region 4 presents a barrier to the extension of the nascent RNA as it emerges from the RNA exit channel. Our findings support the view that the transition from initiation to elongation involves a staged disruption of σ-core interactions.
Charles De Gaulle and the Nuclear Revolution
Authors: Gordon Philip H.
Published: March 2005

Charles de Gaulle recognized from the beginning that nuclear bomb would have immense consequences although he continued to believe in the continuation of past patterns of great‐power conflict, war, and behaviour. By the end of his two‐decade ’nuclear learning process’, he was convinced that the bomb would have profound effects on how statesmen would use military force. Furthermore, de Gaulle believed that nuclear weapons strengthened the most basic features of the international system by reinforcing the fundamental role of the nation‐state, and by freezing the world into a bipolar order. In short, for de Gaulle, France had to develop its own nuclear weapons in order to ensure French national security, provide great‐power status, respect, national independence, and political influence.
TEACHING COSMOPOLITAN RIGHT
Authors: Waldron Jeremy
Published: March 2005

Jeremy Waldron’s essay centres around Martha Nussbaum’s ideas on cosmopolitan education: Nussbaum argues that we should make ‘world citizenship, rather than democratic or national citizenship, the focus for civic education’. The essay provides just a few examples to illustrate the concrete particularity of the world community for which we are urged by Nussbaum to take responsibility, with the aim of refuting the view of those who condemn cosmopolitanism as an abstraction. The arguments for and against Nussbaum’s idea (universalism vs particularism) are presented, and one of the opposing views highlighted: that cosmopolitan moral education is not just an education in moral ideas; it is (or ought to be) an education in the particular ways in which people have inhabited the world (rather than the purely local aspects of their inhabiting particular territories). The different sections of the chapter look at how a society becomes multicultural, the infrastructure of cultural interaction, the identification of citizenship (citizenship in relation to civic responsibility, exclusivity, subjection), the language of citizenship, and its concrete reality and its cosmopolitan dimensions.
Chapter 6 INTERPRETATION AND PRAGMATICS
Authors: Currie Gregory
Published: March 2005

Argues for an approach to the interpretation of text‐based works within which the idea of a communicative intention is central. The communicative approach, apart from providing detailed, illuminating, and testable theories, transposes very well from conversational exchange to the interpretation of text‐based works, and promises to illuminate aesthetic aspects of our engagement with works. Examines the consequences of this approach for the issue of pluralism about interpretation.
Serum vascular endothelial growth factor165 levels and uterine fibroid volume
Authors: Chen Da‐Chung , Liu Jah‐Yao , Wu Gwo‐Jang , Ku Chih‐Hung , Su Her‐Young , Chen Chi‐Huang
Published: March 2005

Background.  Vascular endothelial growth factor165 (VEGF165) demonstrates increased expression in uterine fibroids. This study aimed to investigate the relationship between serum VEGF165 levels and uterine fibroid volume.

Methods.  On a prospective observational basis, 80 women with symptomatic uterine fibroids underwent hysterectomy. Uterine weight was determined after hysterectomy. Six hours before and 48 h after hysterectomy, serum VEGF165 levels were measured using an enzyme‐linked immunosorbent assay.

Results.  Logistic regression analysis showed no correlation between serum VEGF165 levels and uterine weight (r = 0.0037; P > 0.05). The mean serum VEGF165 level declined significantly from 716.31 ± 457.99 to 581.81 ± 403.32 pg/mL after hysterectomy (P < 0.0001). Controlling for age, body mass index, uterine weight, proliferative or secretory phase, and parity, only parous patients (n = 58) were found to have significantly decreased serum VEGF165 levels after hysterectomy (P = 0.000035), in contrast to nulliparous patients (n = 22; P = 0.15).

Conclusions.  Serum VEGF165 levels do not correlate with uterine fibroid volume, but demonstrate a significant decrease after hysterectomy. The decrease in serum VEGF165 levels after hysterectomy was significant in parous but not in nulliparous patients with uterine fibroids. Serum VEGF165 levels may not predict uterine fibroid development.
Comparison of extraamniotic Foley catheter and intracervical prostaglandin E2 gel for preinduction cervical ripening
Authors: Dalui Rabindranath , Suri Vanita , Ray Pallab , Gupta Indu
Published: March 2005

Background.  The success of induced labor depends on the degree of ripening of cervix. Pharmacological preparations are in widespread use for cervical ripening but are not free from side‐effects and complications. Mechanical methods, i.e. the use of Foley catheter balloon, though effective have not gained much popularity because of the fear of infection. Therefore, this study has been conducted to prove the efficacy and safety of extraamniotic Foley catheter balloon and to compare it with intracervical prostaglandin E2 (PGE2) gel.

Methods.  The randomized prospective study was conducted in the Department of Obstetrics and Gynecology and Medical Microbiology of Nehru Hospital. Hundred women attending the labor ward for induction of labor were divided into two groups: Group A – Foley catheter, Group B – PGE2 gel. Cervical swabs before and after the insertion of ripening agents were taken for culture studies. Placental membranes were also sent for culture. Labor outcome, side‐effects, and complications were compared in both the groups. The statistical methods used were Student's compared t‐test, Chi‐square test, and Wilcoxon–Mann–Whitney test.

Results.  Foley catheter proved to be a very effective preinduction ripening agent for unfavorable cervix compared with PGE2 gel, as is evident by the mean Bishop score at 12 h (P < 0.001). Preparation delivery interval was significantly shorter (P < 0.05) in women who underwent cervical ripening with Foley catheter balloon than with the PGE2 gel. No clinical evidence of chorioamnionitis was present in both the groups.

Conclusion.  This study concludes that extraamniotic Foley catheter balloon is an effective, safe, simple, low‐cost, reversible, non‐pharmacological mechanical method of preinduction cervical ripening.
On Doing Being a Stranger: The Practical Constitution of Civil Inattention
Authors: HIRSCHAUER STEFAN
Published: March 2005

ABSTRACT:The article takes on a less developed aspect of the sociology of the stranger: the normalized non‐relations people in urban settings establish in their effort to stay strangers for one another. How is their “civil inattention”accomplished in practice? What is the social orderliness of “asocial” relations? In order to answer these questions the article uses the elevator as a sociological research instrument allowing for a highly detailed investigation in structural problems of public encounters: bodily navigation, contact avoidance, feigned preoccupation, and the blocking of the automatism by which co‐present bodies start interactions. The setting used for the investigation also raises questions about how the artifact and the bodies present are integrated into the interaction order. The “heteromobile” of the elevator offers specific sociotechnical scripts for interaction. While the human actors work hard at doing nothing, their bodies seem to take over their agency. The specific challenge of elevator riding for the enactment of indifference is the vanishing of actors: undoing presence.
Sol–Gel Processing for Optical Communication Technology
Authors: Bhandarkar Suhas
Published: March 2005

Sol–gel is a versatile technology offering advantageous processing of complex shapes as well as material compositions. In the realm of optical communications, the applicability of a number of dielectric and hybrid materials in various photonic devices makes the technology particularly appealing vis‐a‐vis the vapor‐phase methods that dominate the field today. One can find numerous reports of sol–gel processing for photonic components, although instances where this has been developed for product manufacture are far fewer. Here, we examine the different classes of optical communication devices from fibers to waveguides to photonic crystals and the ability of sol–gel processing to address their needs. Successful deployment appears to depend on two aspects: making innovative modifications to the traditional concept and developing supporting technologies to overcome the key drawbacks.