bluuebunny/crossref_metadata_2025_split huggingface dataset:
Meta‐heuristic algorithms for channel scheduling problem in wireless sensor networks
Authors: Jang Kil‐Woong 
Published: April 2011

SUMMARYThe channel scheduling problem is to decide how to commit channels for transmitting data between nodes in wireless networks. This problem is one of the most important problems in wireless sensor networks. In this problem, we aim to obtain a near‐optimal solution with the minimal energy consumption within a reasonable time. As the number of nodes increases in the network, however, the amount of calculation for finding the solution would be too high. It can be difficult to obtain an optimal solution in a reasonable execution time because this problem is NP‐hard. Therefore, most of the recent studies for such problems seem to focus on heuristic algorithms. In this paper, we propose efficient channel scheduling algorithms to obtain a near‐optimal solution on the basis of three meta‐heuristic algorithms; the genetic algorithm, the Tabu search, and the simulated annealing. In order to make a search more efficient, we propose some neighborhood generating methods for the proposed algorithms. We evaluate the performance of the proposed algorithms through some experiments in terms of energy consumption and algorithm execution time. The experimental results show that the proposed algorithms are efficient for solving the channel scheduling problem in wireless sensor networks. Copyright © 2011 John Wiley & Sons, Ltd.
Neural crest cell communication involves an exchange of cytoplasmic material through cellular bridges revealed by photoconversion of KikGR
Authors: McKinney Mary Cathleen , Stark Danny A. , Teddy Jessica , Kulesa Paul M. 
Published: April 2011

AbstractNeural crest (NC) cells invade the vertebrate embryo in ordered migratory streams, yet it is unclear whether cells communicate to maintain spacing and direction. Here, we examined NC cell communication in detail, using optical highlighting and photobleaching to monitor cell contact dynamics. We observed cytoplasmic transfer between NC cell neighbors through thin cellular bridges. The transfer of molecules between NC cells was bi‐directional, not at equal rates, and independent of bridge dynamics. The cytoplasmic transfer was prevalent in recently divided NC cells. Molecular simulations, based on Brownian motion and measured cell volumes, predicted that simple diffusion could not account for observed cytoplasmic transfer rates. Cell tracking revealed that exchange of cytoplasmic material preceded the re‐orientation of cells to the direction of migration. Our data suggest a mechanism by which NC cells communicate position information through the formation of cellular bridges that allow exchange of cytoplasmic material through active transport. Developmental Dynamics 240:1391–1401, 2011. © 2011 Wiley‐Liss, Inc.
Photochemically Controlled Supramolecular Curdlan/Single‐Walled Carbon Nanotube Composite Gel: Preparation of Molecular Distaff by Cyclodextrin Modified Curdlan and Phase Transition Control
Authors: Tamesue Shingo , Takashima Yoshinori , Yamaguchi Hiroyasu , Shinkai Seiji , Harada Akira 
Published: April 2011

AbstractWe propose a single‐walled carbon nanotube (SWNT) composite with a molecular recognition property, which is prepared by mixing α‐cyclodextrin‐modified curdlan (CD‐CUR) with SWNTs in water. The visible/near‐infrared (Vis/NIR) spectrum of the CD‐CUR/SWNT composite exhibits characteristic absorption bands corresponding to the band‐gap transitions for van Hove singularities of metallic and semiconductor carbon nanotubes. The structure of the CD‐CUR/SWNT composites was characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The TEM and AFM images show that the CD‐CUR/SWNT composite exhibits dispersed fibers with a narrow fiber diameter distribution, which suggests that CD‐CUR helically wraps around SWNTs to form one‐dimensional superstructural composites. Because we hypothesized that the CD‐CUR/SWNT composite possesses a molecular recognition property, we attempted to create supramolecular hydrogels containing SWNTs by using a CD‐CUR/SWNT composite and a guest polymer (pAC12Azo) with an azobenzene guest pendant. The CD‐CUR/SWNT composite selectively forms supramolecular hydrogels with pAC12Azo. UV irradiation (λ = 365 nm) of the supramolecular hydrogel decreases the viscosity upon isomerization of the trans‐azo group to give the sol. In contrast, irradiation with visible light at λ = 430 nm (or heating) of the sol state recovers the viscosity to restore the hydrogel within 2 min, indicating that irradiation affects the association and dissociation between the α‐CD unit and the azobenzene unit during phase transition. In summary, we demonstrate the formation of a CD‐CUR/SWNT composite and a photoresponsive sol–gel supramolecular SWNT hydrogel.
Development and validation of first‐ever speech‐specific perceptual speech evaluation tool for patients with head and neck cancer: The London speech evaluation (LSE) Scale
Authors: Dwivedi Raghav C. , Rose Suzanne St. , Chisholm Edward J. , Kerawala Cyrus J. , Clarke Peter M. , Nutting Christopher M. , Rhys‐Evans Peter H. , Harrington Kevin J. , Kazi Rehan 
Published: April 2011

AbstractBackgroundThe aim of this study was to develop and validate the first ever speech‐specific perceptual speech‐evaluation tool for patients with head and neck cancer.MethodsFive speech parameters (intelligibility, articulation, speech rate, nasality, and asthenia) and overall grade were included and evaluated. Speech samples of 117 subjects were recorded on electroglottograph equipment using a standard protocol and were independently judged and rated by 3 experienced speech and language therapists and re‐rated 12 weeks apart.ResultsAmong patients the Cronbach's alpha (α) coefficients for internal consistency for connected speech were 0.89, whereas for single words the α coefficients ranged between 0.80 and 0.84. The Spearman's correlation coefficients for intra‐rater reliability for connected speech and words varied between 0.30 and 0.90 and 0.49 and 0.76, respectively, whereas for inter‐rater reliability the coefficients ranged between 0.53 and 0.99 and 0.56 and 0.99, respectively. For construct validity, the Spearman's correlation coefficient ranged between 0.41 and 0.55.ConclusionsThe London Speech Evaluation (LSE) scale demonstrated a high reliability and validity in our cohort of patients with head and neck cancer. surgery. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Sternocleidomastoid muscle flap in preventing Frey's syndrome after parotidectomy: A systematic review
Authors: Sanabria Alvaro , Kowalski Luiz P. , Bradley Patrick J. , Hartl Dana M. , Bradford Carol R. , de Bree Remco , Rinaldo Alessandra , Ferlito Alfio 
Published: April 2011

AbstractBackgroundParotidectomy is a common procedure and Frey's syndrome (gustatory sweating) is a common side effect. The current literature was assessed concerning the effectiveness of the sternocleidomastoid muscle (SCM) flap to prevent Frey's syndrome after parotidectomy.MethodsA bibliography search was conducted for studies published between 1966 and 2010 and included randomized controlled trials (RCTs) or cohort studies with patients undergoing parotidectomy with facial nerve preservation. The outcome measures of particular interest were the incidence of Frey's syndrome and cosmetic impairment.ResultsIn all, 12 studies were selected (1 meta‐analysis of all interventions to prevent Frey's syndrome, 2 RCTs, and 9 cohort studies). The trials were too heterogeneous to perform a meta‐analysis on the effect of the SCM flap. The results reported by the authors of each study suggest an objective decrease in Frey's syndrome when the SCM flap was used, but there was no difference in the patients' subjective reporting of symptoms. However, this conclusion is prone to the biases inherent in these studies, and thus overall it is impossible to make any recommendation.ConclusionCurrent reported evidence is inconclusive as to the use of SCM muscle flap as an intervention to prevent Frey's syndrome following parotid surgery. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Near infrared fluorescence‐guided real‐time endoscopic detection of peritoneal ovarian cancer nodules using intravenously injected indocyanine green
Authors: Kosaka Nobuyuki , Mitsunaga Makoto , Longmire Michelle R. , Choyke Peter L. , Kobayashi Hisataka 
Published: April 2011

AbstractNear infrared fluorescence‐guidance can be used for the detection of small cancer metastases and can aid in the endoscopic management of cancer. Indocyanine green (ICG) is a Food and Drug Administration (FDA)‐approved fluorescence agent. Through non‐specific interactions with serum proteins, ICG achieves enhanced permeability and retention (EPR) effects. Yet, ICG demonstrates rapid clearance from the circulation. Therefore, ICG may be an ideal contrast agent for real‐time fluorescence imaging of tumors. To evaluate the usefulness of real‐time dual fluorescence and white light endoscopic optical imaging to detect tumor implants using the contrast agent ICG, fluorescence‐guided laparoscopic procedures were performed in mouse models of peritoneally disseminated ovarian cancers. Animals were administered intravenous ICG or a control contrast agent, IR800‐conjugated to albumin. The ability to detect small ovarian cancer implants was then compared. Using the dual view microendoscope, ICG clearly enabled visualization of peritoneal ovarian cancer metastatic nodules derived from SHIN3 and OVCAR5 cells at 6 and 24 hr after injection with significantly higher tumor‐to‐background ratio than the control agent, IR800‐albumin (p < 0.001). In conclusion, ICG has the desirable properties of having both EPR effects and rapid clearance for the real‐time endoscopic detection of tiny ovarian cancer peritoneal implants compared to a control macromolecular agent with theoretically better EPR effects but longer circulatory retention. Given that ICG is already FDA‐approved and has a long track record of human use, this method could be easily translated to the clinic as a robust tool for fluorescence‐guided endoscopic procedures for the management and treatment of cancer.
Visual analogue scales: how can we interpret them in experimental studies of irritation in the eyes, nose, throat and airways?
Authors: Ernstgård Lena , Bottai Matteo 
Published: April 2011

ABSTRACTThe aim of this study was to investigate if visual analogue scales (VAS) of objective symptoms could be validated against objective measurements in exposure studies of chemical vapours in humans. This validation comprises the results of symptom ratings of irritation and objective measurements of effects of the eye, nose and throat from studies of nine different chemicals. The objective measurements included blinking frequency as a measure of eye irritation, acoustic rhinometry of nose irritation and the lung function parameter FEV1 of irritation in the throat and airways. The statistical analyses were performed with logistic quantile regression. The results show no overall clear correlation between symptom ratings of irritation and objective measurements, although some statistically significant association was found. The last rating of eye irritation during the exposure was significantly correlated at the 75th percentile to the change in blinking frequency during exposure compared with before (P = 0.013). There was also a significant association between ratings of discomfort in the nose and decrease of the minimal nasal cross‐sectional area at the 75th percentile (P = 0.016). Further, a nonsignificant association between ratings of discomfort in the nose and decrease in nasal volume was found. No correlation between FEV1 and ratings of discomfort in the throat or breathing difficulty was detected. There is a relationship between subjective symptoms and objective measures regarding eye and nose irritation at low chemical exposure levels. Thus, the results of this investigation support the use of VAS in chamber exposure studies and could consequently be expanded into field studies. Copyright © 2011 John Wiley & Sons, Ltd.
Physical origins of the stability of aromatic amino acid core ring‐polycyclic hydrocarbon complexes: A post–Hartree–fock and density functional study
Authors: Czyżnikowska Żaneta , Bartkowiak Wojciech 
Published: April 2011

AbstractNoncovalent interactions between four aromatic amino acid core rings and polycyclic hydrocarbons (up to 58 carbon atoms) were investigated at the post–Hartree–Fock level of theory and with the aid of the density functional theory. In particular, the intermolecular interaction energy was partitioned into physically meaningful contributions using the hybrid variational–perturbational decomposition scheme. It was found that electrostatic interactions are completely quenched by associated exchange repulsion. In terms of magnitude, the latter component is 2–3 times larger than the former one. As a result, the complexes are solely stabilized by attractive dispersion forces. Moreover, the SAPT–DFT framework was employed with an eye toward a comparison of various approaches used to compute the dispersion energy. As part of a model study, the impact of the correct representation of the electron density on the description of intermolecular interactions was analyzed as well. It was shown that in the case of the investigated complexes, it is sufficient to augment the basis set with diffuse functions only in the region of the mutual overlap of molecules in stacked alignment. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Mechanical properties of 7–10 mm bone grafts and small slurry grafts in impaction bone grafting
Authors: Xu Zheng‐Jian , Chen Lian‐Yi , Zhong Cheng , Tan Yan‐Bin , He Rong‐Xin 
Published: April 2011

AbstractWe compared the mechanical properties of morselized cancellous bone grafts of two sizes: 7–10 mm bone and small slurry bone (about 2 mm). The in vitro test was designed to simulate the hammer and impactor system for impaction bone grafting used in hip arthroplasty clinical practice. The 7–10 mm bone grafts showed higher height, elastic modulus, and massive extrusion strength than those of the small slurry bone grafts. No difference was found in yield strength. The bone mineral density of the 7–10 mm grafts continued to increase during impaction and became higher than that of the small slurry bone grafts after 10 impactions. Our results demonstrated that the small slurry bone grafts exhibit worse mechanical properties as compared with the 7–10 mm bone grafts, which implies that the use of this material in reconstruction of a bone defect in the acetabulum should be limited. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 1491–1495, 2011
pH‐Responsive Micelles Based on Amphiphilic Block Copolymers Bearing Ortho Ester Pendants as Potential Drug Carriers
Authors: Tang Rupei , Ji Weihang , Wang Chun 
Published: April 2011

AbstractAmphiphilic block copolymers (PEG‐b‐PEYM) bearing acid‐labile ortho ester pendant chains were synthesized by atom transfer radical polymerization, and the effect of chain‐length of the ortho‐ester‐bearing PEYM block on micelle properties was investigated. The length of the PEYM block affected the critical micelle concentration and pH‐dependent average particle size but not the kinetics of side‐chain hydrolysis. A hydrophobic dye, Nile red, was loaded in the micelles. Both the loading content and the size of the loaded micelles were influenced by the length of the PEYM block, whereas the release kinetics of Nile red was not. Provided that these acid‐labile micelles are completely cell compatible, they are potentially useful bio‐responsive nanocarriers for enhancing the efficacy of hydrophobic drugs. magnified image
Osteopontin polymorphic susceptibility factor for Parkinson's disease among patients with Gaucher disease
Authors: Ribner Avigayil , Altarescu Gheona , Zimran Ari , Elstein Deborah 
Published: April 2011

AbstractBackground:There is an increased incidence of Parkinson's disease among obligate carriers of the common glucocerebrosidase mutations, and among patients with Parkinson disease there is an increased number who are carriers of glucocerebrosidase mutations. A Gaucher mutation is considered a susceptibility factor for Parkinson's disease. Osteopontin single‐nucleotide polymorphism–66 is associated with Lewy body disease and considered a susceptibility factor. The aim of this study was to ascertain whether Gaucher patients with parkinsonism carry the osteopontin single‐nucleotide polymorphism‐66 polymorphic genotype TT to a greater extent than other Gaucher patients.Methods:Seventy adult patients with at least 1 allele having the common N370S Gaucher mutation including 10 patients with Parkinson's disease were included.Results:There was no statistically significant difference in incidence of the TT genotype in patients with clinically symptomatic Parkinson's disease (88.9%) and other Gaucher patients (72.1%).Conclusions:This may partly explain the increased incidence of Parkinson's disease associated with Gaucher mutations. © 2011 Movement Disorder Society
Cerebrospinal fluid Tau/α‐synuclein ratio in Parkinson's disease and degenerative dementias
Authors: Parnetti Lucilla , Chiasserini Davide , Bellomo Gianni , Giannandrea David , De Carlo Claudia , Qureshi Mohamed M. , Ardah Mustafa T. , Varghese Shiji , Bonanni Laura , Borroni Barbara , Tambasco Nicola , Eusebi Paolo , Rossi Aroldo , Onofrj Marco , Padovani Alessandro , Calabresi Paolo , El‐Agnaf Omar 
Published: April 2011

AbstractAlthough alpha‐synuclein is the main constituent of Lewy bodies, cerebrospinal fluid determination on its own does not seem fundamental for the diagnosis of synucleinopathies. We evaluated whether the combination of classical biomarkers, Aβ1–42, total tau, phosphorylated tau, and α‐synuclein can improve discrimination of Parkinson's disease, dementia with Lewy bodies, Alzheimer's disease, and frontotemporal dementia. Aβ1–42, total tau, phosphorylated tau, and α‐synuclein were measured in a series of patients with Parkinson's disease (n = 38), dementia with Lewy bodies (n = 32), Alzheimer's disease (n = 48), frontotemporal dementia (n = 31), and age‐matched control patients with other neurological diseases (n = 32). Mean α‐synuclein levels in cerebrospinal fluid were significantly lower in the pathological groups than in cognitively healthy subjects. An inverse correlation of α‐synuclein with total tau (r = −0.196, P < .01) was observed. In the group of patients with Parkinson's disease, Aβ1–42, total tau, and phosphorylated tau values were similar to controls, whereas total tau/α‐synuclein and phosphorylated tau/α‐synuclein ratios showed the lowest values. Cerebrospinal fluid α‐synuclein alone did not provide relevant information for Parkinson's disease diagnosis, showing low specificity (area under the curve, 0.662; sensitivity, 94%; specificity, 25%). Instead, a better performance was obtained with the total tau/α‐syn ratio (area under the curve, 0.765; sensitivity, 89%; specificity, 61%). Combined determination of α‐synuclein and classical biomarkers in cerebrospinal fluid shows differential patterns in neurodegenerative disorders. In particular, total tau/α‐synuclein and phosphorylated tau/α‐synuclein ratios can contribute to the discrimination of Parkinson's disease. © 2011 Movement Disorder Society
Could thiazolidinediones increase the risk of heart failure in Friedreich's ataxia patients?
Authors: García‐Giménez José L. , Sanchis‐Gomar Fabián , Pallardó Federico V. 
Published: April 2011

AbstractClinical evidence and the recent decisions of the European Medicines Agency and the Food and Drug Administration challenge the safety of thiazolidinediones treatment. Recently, this treatment has been suggested for Friedreich's ataxia because thiazolidinediones improve neurological symptoms. Hypertrophic cardiomyopathy is the most prevalent cardiac feature and the cause of premature death in Friedreich's ataxia patients. We recommend that therapy with peroxisome proliferator‐activated receptor‐gamma agonists like thiazolidinediones be taken with caution, as they cause a decrease in the number of fast fibers and an increase in mitochondrial biogenesis in cardiac muscle because of the induction of peroxisome proliferator‐activated receptor‐gamma coactivator‐1α. Furthermore, the incidence of heart failure may increase when thiazolidinediones are combined with insulin, and moreover, they produce cyclooxygenase 2 inhibition, inducing a thrombotic response. Thus, patients are predisposed to adverse cardiovascular outcomes. In our opinion, the possible fatal consequences must be taken into account when peroxisome proliferator‐activated receptor‐gamma agonist drugs are considered as possible therapeutic agents for Friedreich's ataxia patients. © 2011 Movement Disorder Society
A new design and rationale for 3D orthogonally oversampled k‐space trajectories
Authors: Pipe James G. , Zwart Nicholas R. , Aboussouan Eric A. , Robison Ryan K. , Devaraj Ajit , Johnson Kenneth O. 
Published: April 2011

AbstractA novel center‐out 3D trajectory for sampling magnetic resonance data is presented. The trajectory set is based on a single Fermat spiral waveform, which is substantially undersampled in the center of k‐space. Multiple trajectories are combined in a “stacked cone” configuration to give very uniform sampling throughout a “hub,” which is very efficient in terms of gradient performance and uniform trajectory spacing. The fermat looped, orthogonally encoded trajectories (FLORET) design produces less gradient‐efficient trajectories near the poles, so multiple orthogonal hub designs are shown. These multihub designs oversample k‐space twice with orthogonal trajectories, which gives unique properties but also doubles the minimum scan time for critical sampling of k‐space. The trajectory is shown to be much more efficient than the conventional stack of cones trajectory, and has nearly the same signal‐to‐noise ratio efficiency (but twice the minimum scan time) as a stack of spirals trajectory. As a center‐out trajectory, it provides a shorter minimum echo time than stack of spirals, and its spherical k‐space coverage can dramatically reduce Gibbs ringing. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Quantification of myocardial blood flow using model based analysis of first‐pass perfusion MRI: Extraction fraction of Gd‐DTPA varies with myocardial blood flow in human myocardium
Authors: Ishida Masaki , Ichihara Takashi , Nagata Motonori , Ishida Nanaka , Takase Shinichi , Kurita Tairo , Ito Masaaki , Takeda Kan , Sakuma Hajime 
Published: April 2011

AbstractFor the absolute quantification of myocardial blood flow (MBF), Patlak plot‐derived K1 need to be converted to MBF by using the relation between the extraction fraction of gadolinium contrast agent and MBF. This study was conducted to determine the relation between extraction fraction of Gd‐DTPA and MBF in human heart at rest and during stress. Thirty‐four patients (19 men, mean age of 66.5 ± 11.0 years) with normal coronary arteries and no myocardial infarction were retrospectively evaluated. First‐pass myocardial perfusion MRI during adenosine triphosphate stress and at rest was performed using a dual bolus approach to correct for saturation of the blood signal. Myocardial K1 was quantified by Patlak plot method. Mean MBF was determined from coronary sinus flow measured by phase contrast cine MRI and left ventricle mass measured by cine MRI. The extraction fraction of Gd‐DTPA was calculated as the K1 divided by the mean MBF. The extraction fraction of Gd‐DTPA was 0.46 ± 0.22 at rest and 0.32 ± 0.13 during stress (P < 0.001). The relationship between extraction fraction (E) and MBF in human myocardium can be approximated as E = 1 − exp(−(0.14 × MBF + 0.56)/MBF). The current results indicate that MBF can be accurately quantified by Patlak plot method of first‐pass myocardial perfusion MRI by performing a correction of extraction fraction. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.