bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymmetric halo and symmetric Single‐Halo Dual‐Material Gate and Double‐Halo Dual‐Material Gate n‐MOSFETs characteristic parameter modeling
Authors: Sarkar Angsuman , De Swapnadip , Sarkar Chandan Kumar 
Published: January 2012

SUMMARYThis paper presents an analytical subthreshold surface potential model of novel structures called asymmetric pocket‐implanted Double‐Halo Dual‐Material Gate (DHDMG) and Single‐Halo Dual‐Material Gate (SHDMG) Metal Oxide Semiconductor Field Effect Transistor (MOSFET), which combines the advantages of both the channel engineering (halo) and the gate engineering techniques (dual‐material gate) to effectively suppress the short‐channel effects (SCEs). The model is derived using the pseudo‐2D analysis by applying the Gauss's law to an elementary rectangular box in the channel depletion region, considering the surface potential variation with the channel depletion layer depth. The asymmetric pocket‐implanted model takes into account the effective doping concentration of the two linear pocket profiles at the source and the drain ends. The inner fringing field capacitances are also considered in the model for accurate estimation of the subthreshold surface potential at the two ends of the MOSFET. The same model is used to find the characteristic parameters for dual‐material gate with single‐halo and double‐halo implantations. It is concluded that the DHDMG device structure exhibits better suppression of the SCEs and the threshold voltage roll‐off than a pocket‐implanted and SHDMG MOSFET after investigating the characteristics parameter improvement. In order to validate our model, the modeled expressions have been extensively compared with the simulated characteristics obtained from the 2D device simulator DESSIS. A nice agreement is achieved with a reasonable accuracy over a wide range of device parameter and bias condition. Copyright © 2012 John Wiley & Sons, Ltd.
Synovial fluid microanalysis allows early diagnosis of ceramic hip prosthesis damage
Authors: Stea Susanna , Traina Francesco , Beraudi Alina , Montesi Monica , Bordini Barbara , Squarzoni Stefano , Sudanese Alessandra , Toni Aldo 
Published: January 2012

AbstractThe first clinical sign of ceramic hip prosthesis failure is hip noise. We therefore investigated whether isolation, observation at scanning electron microscopy, and chemical identification with microanalysis of particles from synovial fluid of “noisy hip” could be predictive of ceramic damage. Firstly, the level of “physiological wear” of well functioning ceramic‐on‐ceramic hip prostheses was assessed with this method, then the test was validated as diagnostic method for liner fracture. Twelve asymptomatic patients were enrolled to demonstrate the first aim; 39 cases of noisy hip (GROUP 1), and 7 cases of pending failure not related to ceramic (GROUP 2) were enrolled for the second aim. The analysis of the synovial fluid of the 12 asymptomatic patients allowed to set the “physiological wear” threshold. The analysis of GROUP 1 hips demonstrated the presence of ceramic particles (2 physiological, 12 mild, and 25 strong). The analysis of GROUP 2 showed a physiological presence of ceramic particles in all cases. Revision surgery in GROUP 1 was performed in 16 hips out 25 with strong ceramic particle presence and 2 out of 12 with mild ceramic particle presence. Failure of the ceramic component was evident in all but one of these cases, while the integrity of components was demonstrated in all seven hips of GROUP 2. Synovial fluid microanalysis can be a useful surrogate in predicting ceramic failure particularly when a strong presence of ceramic particles is observed. On the contrary there is not enough evidence to predict ceramic failure in presence of mild positivity. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1312–1320, 2012
High expression of CD73 as a poor prognostic biomarker in human colorectal cancer
Authors: Wu Xian‐Rui , He Xiao‐Sheng , Chen Yu‐Feng , Yuan Rui‐Xue , Zeng Yang , Lian Lei , Zou Yi‐Feng , Lan Nan , Wu Xiao‐Jian , Lan Ping 
Published: January 2012

AbstractBackground and ObjectivesTo investigate the expression dynamics of CD73 and its prognostic significance in human colorectal cancer (CRC).MethodsCD73 expression dynamics were detected by Western blotting. Immunohistochemistry was used to examine the expression of CD73 in CRC tissues from two independent cohorts by tissue microarrays. The optimal cutpoint of CD73 expression was assessed by the X‐tile program.ResultsWestern blotting analysis demonstrated that CD73 expression in CRC was significantly higher than in normal colorectal tissues. According to the X‐tile program, the cutpoint for high expression of CD73 in CRC was determined when CD73 expression index was more than 5.9. High expression of CD73 was observed in 44.8% and 50.4% of CRC in the training and validation cohorts, respectively. Overexpression of CD73 was significantly correlated with tumor differentiation, nodal status, American Joint Committee on Cancer stage. Patients with high expression of CD73 had a poorer overall survival rate compared with patients with low expression of CD73 in both cohorts. In multivariate Cox regression analysis, overexpression of CD73 was proven to be an independent prognostic biomarker for CRC.ConclusionsHigh expression of CD73 can be an independent and useful biomarker for predicting the poor survival of patients with CRC. J. Surg. Oncol. 2012; 106:130–137. © 2012 Wiley Periodicals, Inc.
Tribology of fluorinated diamond‐like carbon coatings: first principles calculations and sliding experiments
Authors: Sen F. G. , Qi Y. , Alpas A. T. 
Published: January 2012

ABSTRACTSliding contact experiments and first principles calculations were conducted to study tribological properties of aluminium and fluorinated diamond‐like carbon (F‐DLC) surfaces. Sliding tests between Al and an F‐DLC coating generated a low coefficient of friction (COF) of 0.09–0.14 and led to the formation of carbonaceous transfer layers containing AlF3 on the Al surfaces as determined by X‐ray photoelectron spectroscopy. An interface model that examined the interactions between Al (111) and F‐terminated diamond (111) surfaces revealed that F atoms would transfer to the Al surface in increasing quantities with an increase in the contact pressure and the F transfer would lead to the formation of a stable AlF3 compound at the Al surface. The generation of repulsive forces between two F‐passivated surfaces as a result of the F transfer to the Al surface was shown to be responsible for the low COF between Al and F‐DLC. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of π‐Conjugated Polymers Containing Aminoquinoline‐Borafluorene Complexes in the Main‐Chain
Authors: Tokoro Yuichiro , Nagai Atsushi , Tanaka Kazuo , Chujo Yoshiki 
Published: January 2012

AbstractThe regulation of electron transfer between a conjugated polymer and ligands orthogonally connected to the main‐chain is reported. Poly(arylene‐ethynylene)s containing aminoquinoline‐borafluorene complexes in the main‐chain are synthesized in good yields by a Sonogashira–Hagihara coupling. Single crystal X‐ray analysis of a model compound has elucidated the complex's structure in which the aminoquinolate moiety and the borafluorene ring are connected directly and orthogonally. Moreover, the optical properties of the polymers are characterized by UV‐vis absorption and photoluminescence spectra. Perfluorinated alkyl chain‐containing polymers show strong emission, while hydrocarbon chain‐containing ones exhibit only a slight emission. DFT calculation suggests that an electron transfer from the excited main‐chain to the aminoquinolate ligand is suppressed because of the lowered LUMO level by introducing the electron withdrawing groups, resulting in the significant emission.
A Simple and Effective Approach to Vesicles and Large Compound Vesicles via Complexation of Amphiphilic Block Copolymer With Polyelectrolyte in Water
Authors: Salim Nisa V. , Hanley Tracey L. , Waddington Lynne , Hartley Patrick G. , Guo Qipeng 
Published: January 2012

AbstractThis work reports for the first time a simple and effective approach to trigger a spheres‐to‐ vesicles morphological transition from amphiphilic block copolymer/polyelectrolyte complexes in aqueous solution. Vesicles and large compound vesicles (LCVs) were prepared via complexation of polystyrene‐block‐poly(ethylene oxide) (PS‐b‐PEO) with poly(acrylic acid) (PAA) in water and directly visualized using cryo‐TEM. The complexation and morphological transitions were driven by the hydrogen bonding between the complementary binding sites on the PAA and PEO blocks of the block copolymer. The findings in this work suggest that complexation between amphiphilic block copolymer and polyelectrolyte is a viable approach to vesicles and LCVs in aqueous media.
Using frequency‐labeled exchange transfer to separate out conventional magnetization transfer effects from exchange transfer effects when detecting ParaCEST agents
Authors: Lin Chien‐Yuan , Yadav Nirbhay N. , Friedman Joshua I. , Ratnakar James , Sherry A. Dean , van Zijl Peter C. M. 
Published: January 2012

AbstractParamagnetic chemical exchange saturation transfer agents combine the benefits of a large chemical shift difference and a fast exchange rate for sensitive MRI detection. However, the in vivo detection of these agents is hampered by the need for high B1 fields to allow sufficiently fast saturation before exchange occurs, thus causing interference of large magnetization transfer effects from semisolid macromolecules. A recently developed approach named frequency‐labeled exchange transfer utilizes excitation pulses instead of saturation pulses for detecting the exchanging protons. Using solutions and gel phantoms containing the europium (III) complex of DOTA tetraglycinate (EuDOTA‐(gly)−4), it is shown that frequency‐labeled exchange transfer allows the separation of chemical exchange effects and magnetization transfer (MT) effects in the time domain, therefore allowing the study of the individual resonance of rapidly exchanging water molecules (kex >104 s−1) without interference from conventional broad‐band MT. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Comparison of wideband steady‐state free precession and T2‐weighted fast spin echo in spine disorder assessment at 1.5 and 3 T
Authors: Danagoulian Giovanna S. , Qin Lei , Nayak Krishna S. , Colen Rivka R. , Mukundan Srinivasan , Harris Mitchell B. , Jolesz Ferenc A. , Shankaranarayanan Ajit , Copen William A. , Schmidt Ehud J. 
Published: January 2012

AbstractWideband steady‐state free precession (WB‐SSFP) is a modification of balanced steady‐state free precession utilizing alternating repetition times to reduce susceptibility‐induced balanced steady‐state free precession limitations, allowing its use for high‐resolution myelographic‐contrast spinal imaging. Intertissue contrast and spatial resolution of complete‐spine‐coverage 3D WB‐SSFP were compared with those of 2D T2‐weighted fast spin echo, currently the standard for spine T2‐imaging. Six normal subjects were imaged at 1.5 and 3 T. The signal‐to‐noise ratio efficiency (SNR per unit‐time and unit‐volume) of several tissues was measured, along with four intertissue contrast‐to‐noise ratios; nerve‐ganglia:fat, intradural‐nerves:cerebrospinal fluid, nerve‐ganglia:muscle, and muscle:fat. Patients with degenerative and traumatic spine disorders were imaged at both MRI fields to demonstrate WB‐SSFP clinical advantages and disadvantages. At 3 T, WB‐SSFP provided spinal contrast‐to‐noise ratios 3.7–5.2 times that of fast spin echo. At 1.5 T, WB‐SSFP contrast‐to‐noise ratio was 3–3.5 times that of fast spin echo, excluding a 1.7 ratio for intradural‐nerves:cerebrospinal fluid. WB‐SSFP signal‐to‐noise ratio efficiency was also higher. Three‐dimensional WB‐SSFP disadvantages relative to 2D fast spin echo are reduced edema hyperintensity, reduced muscle signal, and higher motion sensitivity. WB‐SSFP's high resolution and contrast‐to‐noise ratio improved visualization of intradural nerve bundles, foraminal nerve roots, and extradural nerve bundles, improving detection of nerve compression in radiculopathy and spinal‐stenosis. WB‐SSFP's high resolution permitted reformatting into orthogonal planes, providing distinct advantages in gauging fine spine pathology. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Skeletal muscle 1H MRSI before and after prolonged exercise. I. muscle specific depletion of intramyocellular lipids
Authors: Vermathen Peter , Saillen Pierre , Boss Andreas , Zehnder Monica , Boesch Chris 
Published: January 2012

AbstractAim of the study was to determine distribution and depletion patterns of intramyocellular lipids (IMCL) in leg muscles before and after two types of standardized endurance exercise. 1H‐magnetic resonance spectroscopic imaging was performed (1) in the thigh of eight‐trained cyclists after exercising on an ergometer for 3 h at 52 ± 8% of maximal speed and (2) in the lower leg of eight‐trained runners after exercising on a treadmill for 3 h at 49 ± 3% of maximal workload. Pre‐exercise IMCL contents were reduced postexercise in 11 out of 13 investigated upper and lower leg muscles (P < 0.015 for all). A strong linear correlation with a slope of ∼0.5 between pre‐exercise IMCL content and IMCL depletion was found. IMCL depletion differed strongly between muscles. Absolute and also relative IMCL reduction was significantly higher in muscles with predominantly slow fibers compared to those with fast fibers. Creatine levels and fiber orientation were stable and unchanged after exercise, while trimethyl‐ammonium groups increased. This is presented in the accompanying paper. In conclusion, a systematic comparison of metabolic changes in cross sections of the upper and lower leg was performed. The results imply that pre‐exercise IMCL levels determine the degree of IMCL depletion after exercise. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Texture analysis of high resolution MRI allows discrimination between febrile and afebrile initial precipitating injury in mesial temporal sclerosis
Authors: Alegro Maryana de Carvalho , Silva Alexandre Valotta , Bando Silvia Yumi , Lopes Roseli de Deus , Martins de Castro Luiz Henrique , HungTsu Wen , Moreira‐Filho Carlos Alberto , Amaro Edson 
Published: January 2012

AbstractA computational pipeline combining texture analysis and pattern classification algorithms was developed for investigating associations between high‐resolution MRI features and histological data. This methodology was tested in the study of dentate gyrus images of sclerotic hippocampi resected from refractory epilepsy patients. Images were acquired using a simple surface coil in a 3.0T MRI scanner. All specimens were subsequently submitted to histological semiquantitative evaluation. The computational pipeline was applied for classifying pixels according to: a) dentate gyrus histological parameters and b) patients' febrile or afebrile initial precipitating insult history. The pipeline results for febrile and afebrile patients achieved 70% classification accuracy, with 78% sensitivity and 80% specificity [area under the reader observer characteristics (ROC) curve: 0.89]. The analysis of the histological data alone was not sufficient to achieve significant power to separate febrile and afebrile groups. Interesting enough, the results from our approach did not show significant correlation with histological parameters (which per se were not enough to classify patient groups). These results showed the potential of adding computational texture analysis together with classification methods for detecting subtle MRI signal differences, a method sufficient to provide good clinical classification. A wide range of applications of this pipeline can also be used in other areas of medical imaging. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Simulations of high permittivity materials for 7 T neuroimaging and evaluation of a new barium titanate‐based dielectric
Authors: Teeuwisse W. M. , Brink W. M. , Haines K. N. , Webb A. G. 
Published: January 2012

AbstractHigh permittivity “dielectric pads” have been shown to increase image quality at high magnetic fields in regions of low radiofrequency transmit efficiency. This article presents a series of electromagnetic simulations to determine the effects of pad size and geometry, relative permittivity value, as well as thickness on the transmit radiofrequency fields for neuroimaging at 7 T. For a 5‐mm thick pad, there is virtually no effect on the transmit field for relative permittivity values lower than ∼90. Significant improvements are found for values between 90 and ∼180. If the relative permittivity is increased above ∼180 then areas of very low transmit efficiency are produced. For a 1‐cm thick pad, the corresponding numbers are ∼60 and ∼120, respectively. Based upon the findings, a new material (barium titanate, relative permittivity ∼150) is used to produce thin (∼5 mm) dielectric pads which can easily be placed within a standard receive head array. Experimental measurements of transmit sensitivities, as well as acquisition of T2‐ and T‐weighted images show the promise of this approach. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Game‐based cross‐layer channel allocation with SVC‐encoded multimedia streams in cognitive radio networks
Authors: Wu Kuo‐Wei , Kuo Wen‐Kuang 
Published: January 2012

SUMMARYThe available unlicensed spectrum is increasingly being used by new wireless technologies, but past measurements show that the licensed spectrum is extremely underutilized. To address this issue, the IEEE 802.22 Working Group is developing a novel wireless air interface standard based on cognitive radios (CRs), i.e. IEEE 802.22 wireless regional area networks (WRANs). Moreover, over the last decade wireless multimedia applications have developed rapidly, raising significant concerns about the quality of service (QoS) of multimedia stream transmissions. In particular, the Joint Video Team (JVT) and ITU‐T Video Coding Experts Group (VCEG) jointly proposed Scalable Video Coding (SVC) as the next‐generation multimedia compression standard. However, the current IEEE 802.22 WRAN draft does not specify QoS mechanisms for SVC‐encoded multimedia stream transmission in CR networks. To resolve this problem, we developed a cross‐layer channel allocation algorithm (CLCAA) and a novel media access control (MAC) protocol to work with the algorithm. The CLCAA adapts to the characteristics of multimedia traffic and variations of wireless channels by determining the weighting of source–destination pair, which is determined by the deadlines of SVC‐encoded multimedia streams, the queuing delay and channel conditions. The CLCAA then allocates transmission opportunities to source–destination pairs based on their weightings and game theory. We also conducted extensive simulations to demonstrate the efficiency of the CLCAA scheme. The simulation results show that the CLCAA scheme not only guarantees QoS for multimedia traffic but also achieves fairness across different streams. Copyright © 2012 John Wiley & Sons, Ltd.
Bevacizumab and irinotecan in children with recurrent or refractory brain tumors: Toxicity and efficacy trends
Authors: Couec Marie‐Laure , André Nicolas , Thebaud Estelle , Minckes Odile , Rialland Xavier , Corradini Nadège , Aerts Isabelle , Bérard Perrine Marec , Bourdeaut Franck , Leblond Pierre ,   on the behalf of the Comité Pharmacologie of the SFCE
Published: January 2012

AbstractBackgroundBevacizumab, a monoclonal antibody targeting the vascular endothelial growth factor, has proven efficacy in some adult tumors; it is now proposed as a new therapeutic strategy for refractory or recurrent brain tumors in some children, either alone or combinated.ProcedureWe retrospectively analyzed 28 children who received bevacizumab on a compassionate basis for refractory or recurrent brain tumors between June 2007 and August 2010 in 7 French centers. Among them, 12 had high‐grade gliomas, 7 low‐grade gliomas, 4 ependymomas, 2 primitive neurectodermal tumors, 3 neuroglial tumors. The median age at start of bevacizumab was 11.0 years. Bevacizumab was administered at 5–10 mg/kg every 2 weeks, with concomitant chemotherapy for 27 patients.ResultsBevacizumab was used in combination with irinotecan in 27 patients. Bevacizumab‐related toxicity was mild. Toxicities reported were grade I–II hypertension (n = 4), proteinuria (n = 1), lymphopenia (n = 2), wound healing delay (n = 2). Whereas tumor reduction could be observed in 6:7 patients with low‐grade gliomas, no efficacy could be documented in patients with high‐grade glioma, nor PNET nor ependymoma.ConclusionBevacizumab‐related acute toxicity appears to be low in children, even in combination with irinotecan. Further prospective trials are required to confirm the hypothetical efficacy of bevacizumab and to assess the risk of long‐term toxicity especially in the youngest children. Pediatr Blood Cancer 2012; 59: 34–38. © 2012 Wiley Periodicals, Inc.
Functional and structural characterization of a thermostable acetyl esterase from Thermotoga maritima
Authors: Levisson Mark , Han Gye Won , Deller Marc C. , Xu Qingping , Biely Peter , Hendriks Sjon , Ten Eyck Lynn F. , Flensburg Claus , Roversi Pietro , Miller Mitchell D. , McMullan Daniel , von Delft Frank , Kreusch Andreas , Deacon Ashley M. , van der Oost John , Lesley Scott A. , Elsliger Marc‐André , Kengen Servé W. M. , Wilson Ian A. 
Published: January 2012

AbstractTM0077 from Thermotoga maritima is a member of the carbohydrate esterase family 7 and is active on a variety of acetylated compounds, including cephalosporin C. TM0077 esterase activity is confined to short‐chain acyl esters (C2–C3), and is optimal around 100°C and pH 7.5. The positional specificity of TM0077 was investigated using 4‐nitrophenyl‐β‐D‐xylopyranoside monoacetates as substrates in a β‐xylosidase‐coupled assay. TM0077 hydrolyzes acetate at positions 2, 3, and 4 with equal efficiency. No activity was detected on xylan or acetylated xylan, which implies that TM0077 is an acetyl esterase and not an acetyl xylan esterase as currently annotated. Selenomethionine‐substituted and native structures of TM0077 were determined at 2.1 and 2.5 Å resolution, respectively, revealing a classic α/β‐hydrolase fold. TM0077 assembles into a doughnut‐shaped hexamer with small tunnels on either side leading to an inner cavity, which contains the six catalytic centers. Structures of TM0077 with covalently bound phenylmethylsulfonyl fluoride and paraoxon were determined to 2.4 and 2.1 Å, respectively, and confirmed that both inhibitors bind covalently to the catalytic serine (Ser188). Upon binding of inhibitor, the catalytic serine adopts an altered conformation, as observed in other esterase and lipases, and supports a previously proposed catalytic mechanism in which Ser hydroxyl rotation prevents reversal of the reaction and allows access of a water molecule for completion of the reaction. Proteins 2012. © 2012 Wiley Periodicals, Inc.