bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation on the proton exchange membrane water electrolyzer using supported anode catalyst
Authors: Sui Sheng , Ma Lirong , Zhai Yuchun 
Published: September 2008

AbstractThe proton exchange membrane water electrolyzer (PEMWE) was investigated using a novel supported anode catalyst. The supported catalyst for the oxygen evolution reaction (OER) was synthesized by chemical reduction and deposition under ultrasonic dispersion. Transmission electron microscopy (TEM) reveals that iridium (Ir) particles with sizes of about 10–40 nm are mainly dispersed on the outside surface of titanium carbide (TiC). The PEMWE using the supported Ir/TiC (40 wt% Ir) as the anode catalyst shows the best performance among the supported catalysts of three different Ir contents. Increasing the cell temperature in the PEMWE can enhance the activity of the catalyst and lower the over‐potential of the electrodes, which can improve the performance of the PEMWE. At a cell temperature of 80 °C and atmospheric pressure, the current densities of the best PEMWE at the potential of 1.8 and 2.0 V are 1002 and 1736 mA/cm2, respectively. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Electrical transport properties of aliovalent cation‐doped CeO2
Authors: Pearce Mark C. , Thangadurai Venkataraman 
Published: September 2008

AbstractWe report the comparative electrical properties of monovalent (Na+), divalent (Ca2+, Sr2+), trivalent (In3+, La3+) and coupled substitution of divalent and trivalent (Ca2+ + Sm3+) cation‐doped CeO2. The investigated samples were prepared by solid‐state reaction (ceramic) using the corresponding metal oxides and salts in the temperature range 1000–1600 °C in air. Powder X‐ray diffraction (PXRD), laser particle size analysis (LPSA), scanning electron microscopy (SEM), and ac impedance spectroscopy measurements were employed for structural, morphology, and electrical characterization. PXRD studies reveal the formation of single‐phase cubic fluorite‐type structures for all investigated samples except those doped with In3+. The variation of lattice parameters is consistent with ionic radii (IR) of the dopant metal ions, with the exception of Na+‐doped CeO2. Our attempt to substitute In3+ for Ce4+ in CeO2 using both ceramic and wet chemical methods was unsuccessful. Furthermore, diffraction peaks attributed to CeO2 and In2O3 were observed up to sintering conditions of 1600 °C. Among the single‐phase compounds investigated, Ce0.85Ca0.05Sm0.1O1.9 exhibits the highest bulk conductivity of 1.3 × 10−3 S/cm at 500 °C with activation energy of 0.64 eV in air. The electrical conductivity data obtained for Ce0.85Ca0.05Sm0.1O1.9 in air and Ar were found to be very similar over the investigated temperature range, indicating the absence of p‐electronic conduction in the high oxygen partial pressure (pO2) range which is consistent with literature reported on Sm‐doped CeO2. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Triboelectricity in the pairs of polymeric materials
Authors: Truncyte D. , Gutauskas M. , Zebrauskas S. , Virbalis J. 
Published: September 2008

AbstractThe influence of electricity of polymeric films and knitted fabrics on friction parameters is analyzed in this work. The variations of the dynamic friction force were determined (under standard DIN 53375) in polymer sliding on the stands made of glass (organic and nonorganic). The dependencies of these variations on the polymer nature and stand mode were analyzed. The determined values of dynamic friction coefficient and dynamic friction force of 10 polymeric materials from the point of view of different stands are presented. The dependencies of friction parameters on triboelectricity and its influence on the formation of adhesion bonds between the components of the sliding pair are described. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Relationship between the deep peroneal nerve and dorsalis pedis artery in the foot: A cadaveric study
Authors: Ranade A.V. , Rajanigandha V. , Rai R. , Ebenezer David A. 
Published: September 2008

AbstractThe aim of our work was to study the relationship between deep peroneal nerve (DPN) and dorsalis pedis artery (DPA) so that the frequency of these variations can be kept in mind by the angiographers and surgeons to ensure safe surgical approach during flap surgery. Ninety‐two legs in 46 cadavers were dissected to study the relationship between DPN and DPA on the dorsum of the foot. The relationship of neurovascular bundle of the dorsum of the foot was classified into four types. Type I: division of the DPN distal to the midpoint between the two malleoli (observed in 26 limbs). In Type II, the division of the DPN was midway between the two malleoli (seen in 20 limbs). Both Type I and II are further divided into two subtypes (a and b) depending upon the crossing pattern of terminal branches of the DPN over DPA. In Type III, multiple branches of DPN were noted in two limbs. In Type IV, the looping pattern of DPN around the DPA was considered and was seen in eight limbs. Awareness of possible variations in the relationship of the DPA to DPN on the dorsum of the foot is important for vascular and reconstructive surgeons. Because it might help in decreasing confusion when considering treatment options like microvascular anastomosis in reconstruction of the leg. Clin. Anat. 21:705–712, 2008. © 2008 Wiley‐Liss, Inc.
Synthesis and Biological Properties of Cylindramide Derivatives: Evidence for Calcium‐Dependent Cytotoxicity of Tetramic Acid Lactams
Authors: Cramer Nicolai , Helbig Sarah , Baro Angelika , Laschat Sabine , Diestel Randi , Sasse Florenz , Mathieu Daniel , Richter Christian , Kummerlöwe Grit , Luy Burkhard , Schwalbe Harald 
Published: September 2008

AbstractTo gain insight into the biological properties of tetramic acid lactam cylindramide 1, the analogues 4 a–d bearing a cyclopentane ring instead of the pentalene unit were prepared by tandem conjugate addition/enolate trapping of cyclopentenone 10; a Sonogashira or Stille coupling, followed by a Julia–Kocienski olefination, macrolactamisation and Lacey–Dieckmann cyclisation were the key steps. The previous NMR structure of cylindramide 1, which was based on NOE and J coupling restraints, could be refined by including residual dipolar coupling data measured for a sample of cylindramide that was aligned in polyacrylonitrile (18 %). Biological screening of cylindramide 1 and its analogues 2‐epi‐1, 20 and 4 revealed promising antiproliferative activity against several tumour cell lines. It turned out that the activity is strongly correlated to the functionalised pentalene system. The configuration of the cyclopentane ring and an intact tetramic acid lactam with the correct configuration seem to play an equal role in the cytotoxicity. The antiproliferative activity was found to be calcium dependent. Phenotypic characterisation of the mode of action showed vacuolisation and vesicle formation in the endoplasmic reticulum.
Interventional cardiac catheterization procedures in pediatric cardiac transplant patients: Transplant surgery is not the end of the road
Authors: Morchi Gira S. , Pietra Biagio , Boucek Mark M. , Chan Kak‐Chen 
Published: September 2008

AbstractObjectives: The objectives of this study are to report the spectrum of cardiac lesions in pediatric patients post‐orthotopic heart transplantation (OHT), the characteristics of patients who develop these lesions, and the feasibility of transcatheter intervention in treating these lesions. Background: Indications for OHT in the pediatric population range from cardiomyopathy to complex congenital heart defects with and without prior palliation. These patients may have residual vascular access and great vessel abnormalities. Methods: Data was collected through retrospective review of all OHT patients at our institution from 1988 to 2005. Results: During the study period, 276 heart transplants were performed. Forty‐seven patients, age 1.6 [0.1–26] years with a weight of 9.5 [3.5–96.0] kilograms, underwent 69 procedures. Patients with original diagnoses of hypoplastic left heart syndrome and failed palliations required intervention most frequently. Sixteen patients, all with a history of left sided disease, developed aortic arch obstruction. Fifteen were successfully treated with balloon angioplasty while one has recurrent supravalve aortic obstruction. Fourteen patients had superior vena cava obstruction treated with balloon angioplasty and/or stent placement. Twelve patients required no further intervention and two required further stent placement. Ilio‐femoral vein occlusion was treated with balloon angioplasty alone in 4 patients and stent placement in 10 patients to achieve vessel patency. Other procedures included treatment of branch pulmonary artery and pulmonary vein stenosis. Conclusion: Anastomotic aortic arch and venous obstructive lesions should be sought following pediatric OHT as they occur in almost 20% of patients and can be successfully addressed using interventional techniques. © 2008 Wiley‐Liss, Inc.
Concurrence of angiographic coronary artery disease in patients with apical ballooning syndrome (tako‐tsubo cardiomyopathy)
Authors: Winchester David E. , Ragosta Michael , Taylor Angela M. 
Published: September 2008

AbstractObjective: To determine the coexistence of coronary artery disease (CAD) in an unselected cohort of patients with apical ballooning syndrome (ABS). Background: ABS is a clinical condition of unknown etiology with symptoms that mimic an acute coronary syndrome and is characterized by the presence of transient left ventricular dysfunction primarily affecting the apex of the heart. Methods: We conducted a retrospective case series in a single tertiary care hospital. Patients were identified by searching for several inclusive discharge diagnoses in all hospitalized patients. Suspected cases were analyzed using prespecified diagnostic criteria. Demographic, clinical, and imaging data were collected. Coronary lesions were assessed by quantitative angiography. Results: Thirty‐one cases of ABS were identified. The majority of the cases were female, and ischemia was documented in all patients by electrocardiographic or cardiac biomarker criteria. Nineteen patients (61.3%) had angiographic evidence of CAD, with multivessel involvement in seven (23%). Nine patients (29%) had luminal stenosis severity greater than 50% in at least one epicardial vessel. Conclusions: In an unselected cohort of patients with ABS, coronary atherosclerosis is commonly present. Whether CAD simply coexists or is related to the pathophysiology of ABS is unclear. © 2008 Wiley‐Liss, Inc.
The use of tapered self‐expanding stents and embolic protection devices in the treatment of stenotic ectatic coronary arteries: A report of two cases
Authors: Le Vu , Abu‐Fadel Mazen , Hennebry Thomas A. 
Published: September 2008

AbstractObjective: The Usage of tapered self‐expanding stents and embolic protection devices in the treatment of stenotic ectatic coronary arteries. Background: Coronary artery ectasia (CAE) is an uncommon disease that is occasionally found during cardiac catheterization. A high incidence of artherosclerotic disease is associated with CAE. Currently, there is no evidence‐based approach for the management of stenotic ectatic coronary arteries (SEC). Methods: Percutaneous intervention with carotid stenting system and embolic protection system to recanalize SEC. Results: We describe two patients who presented with acute coronary syndrome and were found to have CAE with significant stenosis. Both patients underwent percutaneous intervention with RX ACCULINK™ Carotid stenting system and ACCUNET™ embolic protection system (Abbott Laboratories, Abbott Park, IL), successfully. This carotid stenting system is approved by FDA for stenting of extracranial carotid artery stenosis. Conclusion: To the best of our knowledge, this is the first case report illustrating the usage of these devices as an alternative for the treatment of SEC. © 2008 Wiley‐Liss, Inc.
A New Route to the Considerable Enhancement of Glucose Oxidase (GOx) Activity: The Simple Assembly of a Complex from CdTe Quantum Dots and GOx, and Its Glucose Sensing
Authors: Cao Lihua , Ye Jian , Tong Lili , Tang Bo 
Published: September 2008

AbstractA new complex consisting of CdTe quantum dots (QDs) and glucose oxidase (GOx) has been facilely assembled to achieve considerably enhanced enzymatic activity and a wide active temperature range of GOx; these characteristics are attributed to the conformational changes of GOx during assembly. The obtained complex can be simultaneously used as a nanosensor for the detection of glucose with high sensitivity. A mechanism is put forward based on the fluorescence quenching of CdTe QDs, which is caused by the hydrogen peroxide (H2O2) that is produced from the GOx‐catalyzed oxidation of glucose. When H2O2 gets to the surface of the CdTe QDs, the electron‐transfer reaction happens immediately and H2O2 is reduced to O2, which lies in electron hole traps on CdTe QDs and can be used as a good acceptor, thus forming the nonfluorescent CdTe QDs anion. The produced O2 can further participate in the catalyzed reaction of GOx, forming a cyclic electron‐transfer mechanism of glucose oxidation, which is favorable for the whole reaction system. The value of the Michaelis–Menton constant of GOx is estimated to be 0.45 mM L−1, which shows the considerably enhanced enzymatic activity measured by far. In addition, the GOx enzyme conjugated on the CdTe QDs possesses better thermal stability at 20–80 °C and keeps the maximum activity in the wide range of 40–50 °C. Moreover, the simply assembled complex as a nanosensor can sensitively determine glucose in the wide concentration range from micro‐ to millimolar with the detection limit of 0.10 μM, which could be used for the direct detection of low levels of glucose in biological systems. Therefore, the established method could provide an approach for the assembly of CdTe QDs with other redox enzymes, to realize enhanced enzymatic activity, and to further the design of novel nanosensors applied in biological systems in the future.
Racial segregation and disparities in breast cancer care and mortality
Authors: Haas Jennifer S. , Earle Craig C. , Orav John E. , Brawarsky Phyllis , Keohane Marie , Neville Bridget A. , Williams David R. 
Published: September 2008

AbstractBACKGROUND.Questions have existed as to whether residential segregation is a mediator of racial/ethnic disparities in breast cancer care and breast cancer mortality, or has a differential effect by race/ethnicity.METHODS.Data from the Surveillance, Epidemiology, and End Results–Medicare database on white, black, and Hispanic women aged 66 to 85 years with breast cancer were examined for the receipt of adequate breast cancer care.RESULTS.Blacks were less likely than whites to receive adequate breast cancer care (odds ratio [OR], 0.78; 95% confidence interval [CI], 0.71‐0.86). Individuals, both black and white, who lived in areas with greater black segregation were less likely to receive adequate breast cancer care (OR, 0.73; 95% CI, 0.64‐0.82). Black segregation was a mediator of the black/white disparity in breast cancer care, explaining 8.9% of the difference. After adjustment, adequate care for Hispanics did not significantly differ from whites, but individuals, both Hispanic and white, who lived in areas with greater Hispanic segregation were less likely to receive adequate breast cancer care (OR, 0.73; 95% CI, 0.61‐0.89). Although Blacks experienced greater breast cancer mortality than whites, black segregation did not substantially mediate the black‐white disparity in survival, and was not significantly associated with mortality (hazards ratio, 1.03; 95% CI, 0.87‐1.21). Breast cancer mortality did not differ between Hispanics and whites.CONCLUSIONS.Among seniors, segregation mediates some of the black‐white disparity in breast cancer care, but not mortality. Individuals who live in more segregated areas are less likely to receive adequate breast cancer care. Cancer 2008. © 2008 American Cancer Society.
Phase 2 trial of temozolomide using protracted low‐dose and whole‐brain radiotherapy for nonsmall cell lung cancer and breast cancer patients with brain metastases
Authors: Addeo Raffaele , De Rosa Carmine , Faiola Vincenzo , Leo Luigi , Cennamo Gregorio , Montella Liliana , Guarrasi Rosario , Vincenzi Bruno , Caraglia Michele , Del Prete Salvatore 
Published: September 2008

AbstractBACKGROUND.Temozolomide (TMZ), an oral methylating imidazotetrazinone, has antitumor activity against gliomas, malignant melanomas, and brain metastasis and is presently administered as a 5‐day oral schedule every 4 weeks.METHODS.A single‐institution phase 2 clinical trial was conducted to determine the efficacy and the safety profile of a new regimen based on a dose‐intensified, protracted course of TMZ after whole‐brain radiotherapy (WBRT). Patients were eligible if they had at least 1 bidimensionally measurable brain metastasis from breast cancer and nonsmall cell lung cancer (NSCLC). Twenty‐seven patients were treated with 30 grays (Gy) of WBRT with concomitant TMZ (75 mg/m2/day) for 10 days, and subsequent TMZ at a dose of 75 mg/m2 per day for 21 days every 4 weeks, for up to 12 cycles.RESULTS.Two complete responses (7.4%) and 11 partial responses (40.7%) were achieved. The schedule appeared to be well tolerated, with grade 3 toxicity (graded according to National Cancer Institute Common Toxicity Criteria) observed in only 2 patients. The overall median survival was 8.8 months and the median progression‐free survival was 6 months.CONCLUSIONS.The concomitant use of WBRT and protracted low‐dose TMZ appears to be an active, well‐tolerated regimen. The observed antitumor activity suggests the need for further investigation of this schedule in combination with other anticancer agents for the concomitant treatment of brain metastases and primary cancers. Cancer 2008. © 2008 American Cancer Society.
Two‐level preconditioner via a rigid body‐based aggregation for the Schur complement system
Authors: Ko Jin Hwan , Eom Jaesung 
Published: September 2008

AbstractMost aggregation multigrid (MG) methods employ rigid body modes in constructing the prolongators and are famous for fast convergence with good efficiency. However, it is nontrivial to extend these methods to the Schur complement (SC) system, which is a partitioned and condensed system, because the rigid body modes utilize the nodal coordinates. In this work, we proposed a prolongator in an explicit form by transforming the SC system into an alternative system. The two‐level preconditioner derived from the proposed prolongator guaranteed the convergence to be the same as a two‐level MG in a single‐domain system. As demonstrated in a typical shell problem, the two‐level preconditioner showed much faster convergence rate, which is estimated by the condition number based on the Lanczos connection, and also improved the dependency of the convergence on the size of elements and subdomains as compared with a single‐level preconditioner. Copyright © 2008 John Wiley & Sons, Ltd.
Time‐Dependent Density Functional Theory Molecular Dynamics Simulations of Liquid Water Radiolysis
Authors: Tavernelli Ivano , Gaigeot Marie‐Pierre , Vuilleumier Rodolphe , Stia Carlos , Hervé du Penhoat Marie‐Anne , Politis Marie‐Françoise 
Published: September 2008

AbstractThe early stages of the Coulomb explosion of a doubly ionized water molecule immersed in liquid water are investigated with time‐dependent density functional theory molecular dynamics (TD–DFT MD) simulations. Our aim is to verify that the double ionization of one target water molecule leads to the formation of atomic oxygen as a direct consequence of the Coulomb explosion of the molecule. To that end, we used TD–DFT MD simulations in which effective molecular orbitals are propagated in time. These molecular orbitals are constructed as a unitary transformation of maximally localized Wannier orbitals, and the ionization process was obtained by removing two electrons from the molecular orbitals with symmetry 1B1, 3A1, 1B2and 2A1in turn. We show that the doubly charged H2O2+molecule explodes into its three atomic fragments in less than 4 fs, which leads to the formation of one isolated oxygen atom whatever the ionized molecular orbital. This process is followed by the ultrafast transfer of an electron to the ionized molecule in the first femtosecond. A faster dissociation pattern can be observed when the electrons are removed from the molecular orbitals of the innermost shell. A Bader analysis of the charges carried by the molecules during the dissociation trajectories is also reported.
IR, Raman, and UV/Vis Spectra of Corannulene for Use in Possible Interstellar Identification
Authors: Rouillé Gaël , Jäger Cornelia , Steglich Mathias , Huisken Friedrich , Henning Thomas , Theumer Gabriele , Bauer Ingmar , Knölker Hans‐Joachim 
Published: September 2008

AbstractThe spectroscopic characterization of corannulene (C20H10) is carried out by several techniques. The high purity of the material synthesized for this study was confirmed by gas chromatography‐mass spectrometry (GC‐MS). During a high‐performance liquid chromatography (HPLC) process, the absorption spectrum of corannulene in the ultraviolet (UV) and visible (vis) ranges is obtained. The infrared (IR) absorption spectrum is measured in CsI pellets, and the Raman scattering spectrum is recorded for pure crystal grains. In addition to room temperature measurements, absorption spectroscopy in an argon matrix at 12 K is also performed in the IR and UV/Vis ranges. The experimental spectra are compared with theoretical Raman and IR spectra and with calculated electronic transitions. All calculations are based on the density functional theory (DFT), either normal or time‐dependent (TDDFT). Our results are discussed in view of their possible application in the search for corannulene in the interstellar medium.
System synchronization and channel estimation analysis for IEEE 802.16e OFDMA downlink system
Authors: Zhang Zhaoyang , Cheng Peng , Zhou Xiangwei , Qiu Peiliang 
Published: September 2008

AbstractSystem synchronization and channel estimation are two key problems of IEEE 802.16e Orthogonal Frequency Division Multiplex Access (OFDMA) downlink system. According to the standard, system synchronization is completed through the cell search procedure, which includes two steps: frame detection and cell‐ID identification. First, based on the special time‐domain (TD) and frequency‐domain (FD) structures of the preamble, we propose two novel frame detection ms: the TD algorithm and the FD algorithm. Their robustness performance is nearly the same, and the complexity of the FD algorithm is only${{1} \over{31}}$of that of the TD algorithm. Then, an efficient cell‐ID identification algorithm is proposed, in which the necessary correlation length can be dramatically shortened even without anya priorichannel knowledge. Thereby, it greatly reduces the cell search time. As for the problem of channel estimation, a cluster‐based channel estimation method is proposed. It is based on the special pilot distribution of IEEE 802.16e and utilizes the continuity of channel variations to mitigate the impact of time‐variant channel. System simulation results show that the proposed algorithms are both robust and efficient. Copyright © 2008 John Wiley & Sons, Ltd.