bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reliability and validity of a continuous pain registration procedure
Authors: van Wijk A.J. , Lobbezoo F. , Hoogstraten J. 
Published: October 2012

AbstractBackgroundConventional pain rating scales [i.e. visual analogue scales (VAS) or numerical rating scales (NRS)] only provide a summary for different levels of pain felt, while the duration of these levels is not accounted for. If pain can be rated continuously, the area under the curve (AUC) of varying pain intensity over time can be calculated, which integrates varying pain intensity with duration. The present study examined the reproducibility and validity of a continuous pain rating procedure.MethodsTwenty‐eight healthy volunteers participated. Pain was induced using constant current delivered to the non‐dominant forearm using bipolar electrodes. Pain was rated continuously on an electronic VAS monitored by a computer. For each participant, the level of current needed to achieve a weak, mild, slightly moderate and moderate level of pain was determined (part I). Next, participants were asked to rate the painfulness of six periods of electrical stimulation (part II). Unknown to the participants, they were presented with the four levels of current obtained in part I, where the level of current for mild and moderate pain was presented twice (in order to assess consistency). The order of presentation was randomized for all subjects.ResultsIn general, participants produced reliable mean AUCs. In addition, the AUC of pain intensity over time could clearly discriminate between the four levels of pain used in the present study.DiscussionA continuous pain registration procedure, using an AUC approach, may be a promising direction to explore. Results can be improved by allowing more training on the use of the electronic VAS.
Phase composition control of calcium phosphate nanoparticles for tunable drug delivery kinetics and treatment of osteomyelitis. II. Antibacterial and osteoblastic response
Authors: Uskoković Vuk , Desai Tejal A. 
Published: October 2012

AbstractOsteomyelitis has been traditionally treated by the combination of long‐term antibiotic therapies and surgical removal of diseased tissue. The multifunctional material was developed in this study with the aim to improve this therapeutic approach by: (a) enabling locally delivered and sustained release of antibiotics at a tunable rate, so as to eliminate the need for repetitive administration of systemically distributed antibiotics; and (b) controllably dissolving itself, so as to promote natural remineralization of the portion of bone lost to disease. We report hereby on the effect of previously synthesized calcium phosphates (CAPs) with tunable solubilities and drug release timescales on bacterial and osteoblastic cell cultures. All CAP powders exhibited satisfying antibacterial performance against Staphylococcus aureus, the main causative agent of osteomyelitis. Still, owing to its highest drug adsorption efficiency, the most bacteriostatically effective phase was amorphous CAP with the minimal inhibitory concentration of less than 1 mg/mL. At the same time, the positive cell response and osteogenic effect of the antibiotic‐loaded CAP particles was confirmed in vitro for all the sparsely soluble CAP phases. Adsorption of the antibiotic onto CAP particles reversed the deleterious effect that the pure antibiotic exerted on the osteogenic activity of the osteoblastic cells. The simultaneous osteogenic and antimicrobial performance of the material developed in this study, altogether with its ability to exhibit sustained drug release, may favor its consideration as a material base for alternative therapeutic approaches to prolonged antibiotic administration and surgical debridement typically prescribed in the treatment of osteomyelitis. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Mineralized poly(lactic acid) scaffolds loading vascular endothelial growth factor and the in vivo performance in rat subcutaneous model
Authors: Kim Joong‐Hyun , Kim Tae‐Hyun , Jin Guang‐Zhen , Park Jeong‐Hui , Yun Ye‐Rang , Jang Jun‐Hyeog , Kim Hae‐Won 
Published: October 2012

AbstractThe functionalization of degradable polymeric scaffolds with therapeutic molecules such as vascular endothelial growth factor (VEGF) is a key strategy to gain better regenerative ability of damaged bone tissue by stimulating vascularization and tissue perfusion. Here, we combined VEGF with poly(lactic acid) (PLA) porous scaffold, after modifying the PLA surface with calcium phosphate (CaP) mineral. The mineralized PLA scaffold (mPLA) showed more effective loading capacity of VEGF than the PLA without mineralization as well as profiled sustainable release of VEGF for up to a couple of weeks. The VEGF‐loaded mPLA scaffold presented significantly improved proliferation of primary endothelial cells for up to 7 days, with respect to the scaffold without the VEGF loading. The performance of the engineered scaffold was assessed after subcutaneous implantation in rats for 4 weeks. Histological results showed favorable tissue compatibility of both the mPLA scaffolds (with and without VEGF loading), as characterized by infiltration of inflammatory cells, formation of fibrous capsule, and ingrowth of fibroblasts into the matrices. Immunohistochemical staining of the von Willebrand Factor revealed significantly improved formation of neo‐capillaries in the VEGF‐loaded mPLA. Based on this study, the strategy of VEGF loading onto mineralized PLA scaffold is considered beneficial for gaining improved vascularization of the polymeric scaffolds, suggesting potential applications for bone tissue engineering. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Biocompatibility and strength retention of biodegradable Mg‐Ca‐Zn alloy bone implants
Authors: Cho Sung Youn , Chae Soo‐Won , Choi Kui Won , Seok Hyun Kwang , Kim Yu Chan , Jung Jae Young , Yang Seok Jo , Kwon Gyeong Je , Kim Jong Tack , Assad Michel 
Published: October 2012

AbstractThe biocompatibility and strength retention of a Mg‐Ca‐Zn alloy were studied to evaluate its efficacy for osteosynthesis applications. Mg‐Ca‐Zn alloy and self‐reinforced poly l‐lactide (SR‐PLLA) bone screws were implanted into New Zealand rabbits for radiography analysis, micro computed tomography analysis, histomorphometry, hematology, serum biochemistry, histopathology, and inductively coupled plasma mass spectrometry analysis. Bending and torsion tests were performed on intact specimens to find the initial mechanical strength of these Mg‐Ca‐Zn alloy bone screws. Strength retention of the Mg‐Ca‐Zn alloy implants were calculated from in vivo degradation rates and initial mechanical strength. Based on the animal study, Mg‐Ca‐Zn alloy bone screw showed absence of subcutaneous gas pockets, characteristic surface erosion properties, faster degradation rate than SR‐PLLA bone screw, normal reference range of hematology and serum biochemistry, better histopathological response than SR‐PLLA bone screw, and stable concentrations of each constituent element in soft tissues surrounding the implants. The initial strength and strength retention of Mg‐Ca‐Zn alloy were compared with those of various biomaterials. The initial strength of Mg‐Ca‐Zn alloy was higher than those of biostable and biodegradable polymers. The strength retention of Mg‐Ca‐Zn alloy bone screws was similar to those of biodegradable polymer. Therefore, this Mg‐Ca‐Zn alloy represents an excellent biodegradable biomaterial candidate for osteosynthesis applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
STAAR: Statistical analysis of aromatic rings
Authors: Jenkins David D. , Harris Jason B. , Howell Elizabeth E. , Hinde Robert J. , Baudry Jerome 
Published: October 2012

AbstractThe statistical analysis of aromatic rings program allows for an automated search for anion‐π interactions between phenylalanine residues and carboxylic acid moieties of neighboring aspartic acid or glutamic acid residues in protein data bank (PDB) structures. The program is written in C++ and is available both as a standalone code and through a web implementation that allows users to upload and analyze biomolecular structures in PDB format. The program outputs lists of Phe/Glu or Phe/Asp pairs involved in potential anion‐π interactions, together with geometrical (distance and angle between the Phe's center of mass and Glu or Asp's center of charge) and energetic (quantum mechanical Kitaura‐Morokuma interaction energy between the residues) descriptions of each anion‐π interaction. Application of the program on the latest content of the PDB shows that anion‐π interactions are present in thousands of protein structures and can possess strong energies, as low as −8.72 kcal/mol. © 2012 Wiley Periodicals, Inc.
Quantification of left ventricular indices from SSFP cine imaging: Impact of real‐world variability in analysis methodology and utility of geometric modeling
Authors: Miller Christopher A. , Jordan Peter , Borg Alex , Argyle Rachel , Clark David , Pearce Keith , Schmitt Matthias 
Published: November 2012

AbstractPurpose:To assess the impact of “real‐world” practice variation in the process of quantifying left ventricular (LV) mass, volume indices, and ejection fraction (EF) from steady‐state free precession cardiovascular magnetic resonance (CMR) images. The utility of LV geometric modeling techniques was also assessed.Materials and Methods:The effect of short‐axis‐ versus long‐axis‐derived LV base identification, simplified versus detailed endocardial contouring, and visual versus automated identification of end‐systole were evaluated using CMR images from 50 consecutive, prospectively recruited patients. Additionally, the performance of six geometric models was assessed. Repeated measurements were performed on 25 scans (50%) in order to assess observer variability.Results:Simplified endocardial contouring significantly overestimated volumes and underestimated EF (–6 ± 4%, P < 0.0005) compared to detailed contouring. A mean difference of –34g (P < 0.0005) was observed between mass measurements made using short‐axis‐ versus long‐axis‐derived LV base positioning. A technique involving long‐axis LV base identification, signal threshold‐based detailed endocardial contouring, and automated identification of end‐systole had significantly higher observer agreement. Geometric models showed poor agreement with conventional analysis and high variability.Conclusion:Real‐world variability in CMR image analysis leads to significant differences in LV mass, volume and EF measurements, and observer variability. Appropriate reference ranges should be applied. Use of geometric models should be discouraged. J. Magn. Reson. Imaging 2013;37:1213–1222. © 2012 Wiley Periodicals, Inc.
On periodic Hamiltonian elliptic systems with spectrum point zero
Authors: Sun Juntao , Chen Haibo , Chu Jifeng 
Published: October 2012

AbstractIn this paper, we study the existence and multiplicity of solutions for a class of periodic Hamiltonian elliptic systems with spectrum point zero. By applying two recent critical point theorems for strongly indefinite functionals, we present some new criteria to guarantee that Hamiltonian elliptic systems with spectrum point zero have a ground state solution and infinitely many geometrically distinct solutions when the potential satisfies the asymptotically quadratic and weak superquadratic conditions, respectively. Some recent results are extended and improved.
Seizures in juvenile Huntington's disease: Frequency and characterization in a multicenter cohort
Authors: Cloud Leslie J. , Rosenblatt Adam , Margolis Russel L. , Ross Christopher A. , Pillai Jagan A. , Corey‐Bloom Jody , Tully Hannah M. , Bird Thomas , Panegyres Peter K. , Nichter Charles A. , Higgins Donald S. , Helmers Sandra L. , Factor Stewart A. , Jones Randi , Testa Claudia M. 
Published: November 2012

AbstractLittle is known about the epilepsy that often occurs in the juvenile form of Huntington's disease (HD), but is absent from the adult‐onset form. The primary aim of this study was to characterize the seizures in juvenile HD (JHD) subjects with regard to frequency, semiology, defining EEG characteristics, and response to antiepileptic agents. A multicenter, retrospective cohort was identified by database query and/or chart review. Data on age of HD onset, primary HD manifestations, number of CAG repeats, the presence or absence of seizures, seizure type(s), antiepileptic drugs used, subjects' response to antiepileptic drugs (AEDs), and EEG results were assembled, where available. Ninety subjects with genetically confirmed JHD were included. Seizures were present in 38% of subjects and were more likely to occur with younger ages of HD onset. Generalized tonic‐clonic seizures were the most common seizure type, followed by tonic, myoclonic, and staring spells. Multiple seizure types commonly occurred within the same individual. Data on EEG findings and AED usage are presented. Seizure risk in JHD increases with younger age of HD onset. Our ability to draw firm conclusions about defining EEG characteristics and response to AEDs was limited by the retrospective nature of the study. Future prospective studies are required. © 2012 Movement Disorder Society
Progression of cortical thinning in early Parkinson's disease
Authors: Ibarretxe‐Bilbao Naroa , Junque Carme , Segura Barbara , Baggio Hugo C. , Marti Maria J. , Valldeoriola Francesc , Bargallo Nuria , Tolosa Eduardo 
Published: November 2012

AbstractThe aim of this study was to investigate the progression of cortical thinning and gray‐matter (GM) volume loss in early Parkinson's disease (PD). MRI and neuropsychological assessment were obtained at baseline and follow‐up (mean ± standard deviation = 35.50 ± 1.88 months) in a group of 16 early‐PD patients (H & Y stage ≤II and disease duration ≤5 years) and 15 healthy controls matched for age, gender, and years of education. FreeSurfer software was used for the analysis of cortical thickness as well as for cortical and subcortical volumetric analyses. Voxel‐based morphometry analysis was performed using SPM8. Compared to controls, PD patients showed greater regional cortical thinning in bilateral frontotemporal regions as well as greater over‐time total GM loss and amygdalar volume reduction. PD patients and controls presented similar over‐time changes in cognitive functioning. In early‐PD patients, global GM loss, amygdalar atrophy, and cortical thinning in frontotemporal regions are specifically associated with the PD‐degenerative process. © 2012 Movement Disorder Society
Characterization and electrical properties of honeycomb‐patterned poly(ε‐caprolactone)/reduced graphene oxide composite film
Authors: Thinh Phung Xuan , Basavajara C. , Kim Jin Kyoung , Huh Do Sung 
Published: October 2012

AbstractA novel biocompatible composite of poly(ε‐caprolactone) (PCL) was synthesized via in situ ring‐opening polymerization method of ε‐caprolactone in the presence of reduced graphene oxide (RGO). Fourier transform infrared (FTIR) and X‐ray photoelectron spectroscopy (XPS) studies support a strong interaction between PCL and RGO. The crystallization behavior and thermal stability of these composites were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. Honeycomb‐patterned thin films with regular structures were fabricated by casting the composite solution under humid conditions. The temperature‐dependent DC conductivity of the honeycomb‐patterned composite films was studied in the range of 290−330 K, which revealed a semiconducting behavior in the transport properties of the composite films. DC conductivity of the patterned films was increased by increasing the concentration of RGO in the composites and in the increased temperature. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Nonisothermal crystallization kinetics of poly(lactide)—effect of plasticizers and nucleating agent
Authors: Courgneau Cécile , Ducruet Violette , Avérous Luc , Grenet Jean , Domenek Sandra 
Published: October 2012

AbstractPoly(lactide), a bio‐based aliphatic polyester, is a subject to large research effort. One point of optimization is the acceleration of its crystallization kinetics to promote crystallinity under nonisothermal polymer processing conditions by means of compounding with nucleating agents and plasticizers. The nonisothermal crystallization kinetics of neat and formulated poly(L,D‐lactide) (PDLLA) from the melt with talc and polyethylene glycol (PEG) or acetyl tributyl citrate (ATBC) were studied with the help of the Avrami–Jeziorny and Liu–Mo analysis. Talc showed to be a moderately efficient nucleating agent, as it causes only small increase of crystallization kinetics and shows no effect on the crystallization activation energy. A synergistic effect with plasticizers was observed, expanding the crystallization window significantly. PEG was found to be a more efficient plasticizer than ATBC but causes large decrease in the molecular weight average of PDLLA upon thermal treatment. The talc/ATBC system is efficient starting with an ATBC concentration of 9 wt%. The acceleration observed was a crystallization half‐time decrease of 30% compared to neat PLA and reaching maximum crystallization enthalpies even at cooling rate of 25°C min−1. The ATBC/talc system can be recommended as an efficient system for acceleration of nonisothermal crystallization kinetics of PDLLA. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Stereoregular poly‐O‐methyl [m,n]‐polyurethanes derived from D‐mannitol
Authors: Fidalgo Daniela M. , Kolender Adriana A. , Varela Oscar 
Published: October 2012

AbstractNovel linear carbohydrate‐derived [m,n]‐polyurethanes are successfully prepared using D‐mannitol as renewable and low cost starting material. The key comonomer, 1,6‐di‐O‐phenylcarbonyl‐2,3,4,5‐tetra‐O‐methyl‐D‐mannitol is polymerized with a diamine synthesized from D‐mannitol or with alkylenediamines. These polymerization reactions afford, respectively, a [6,6]‐polyurethane entirely based on a carbohydrate derivative or [m,n]‐polyurethanes constituted by a poly‐O‐methyl substituted unit alternating with a polymethylene chain. All these polymers are stereoregular, as result of the C2 axis of symmetry of mannitol. The optically active polyurethanes are characterized by standard methods (FTIR, RMN, GPC, TGA, and DSC). Thus, GPC analysis reveals weight‐average molecular weights between 18,000 and 25,000 Da. Thermal studies (DSC) indicate that the polymers obtained are amorphous materials with Tg values dependent on the structure and chain length of the diamine constituent. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Solution‐processable colorless polyimides derived from hydrogenated pyromellitic dianhydride with controlled steric structure
Authors: Hasegawa Masatoshi , Hirano Daiki , Fujii Mari , Haga Misako , Takezawa Eiichiro , Yamaguchi Shinya , Ishikawa Atsushi , Kagayama Takashi 
Published: October 2012

AbstractThis work presents novel colorless polyimides (PIs) derived from 1R,2S,4S,5R‐cyclohexanetetracarboxylic dianhydride (H″‐PMDA). Isomer effects were also discussed by comparing with PI systems derived from conventional hydrogenated pyromellitic dianhydride, that is, 1S,2R,4S,5R‐cyclohexanetetracarboxylic dianhydride (H‐PMDA). H″‐PMDA was much more reactive with various diamines than H‐PMDA, and the former led to PI precursors with much higher molecular weights. The results can be explained from the quite different steric structures of these isomers. The thermally imidized H″‐PMDA‐based films were colorless regardless of diamines because of inhibited charge‐transfer interaction. In particular, the H″‐PMDA/4,4′‐oxydianiline system simultaneously achieved a very high Tg exceeding 300 °C, high toughness (elongation at break > 70%), and good solution processability. In contrast, the H‐PMDA‐based counterparts were essentially insoluble. The outstanding solubility of the former probably results from disturbed chain stacking by its nonplanar steric structure. An advantage of chemical imidization process is also proposed. In some cases, a copolymerization approach with an aromatic tetracarboxylic dianhydride was effective to improve the thermal expansion property. The results suggest that the H″‐PMDA‐based PI systems can be promising candidates for novel high‐temperature plastic substrate materials in electronic paper displays. A potential application as optical compensation film materials in liquid crystal displays (LCD) is also proposed in this work. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Depth characterization by confocal raman microscopy of oxygen inhibition in free radical photopolymerization of acrylates: Contribution of the thiol chemistry
Authors: Courtecuisse François , Cerezo Javier , Croutxé‐Barghorn Céline , Dietlin Céline , Allonas Xavier 
Published: October 2012

AbstractThe oxygen inhibition of acrylate photopolymerization using visible light was depth characterized by confocal Raman microscopy. The sample thickness was found to influence the depth conversion profile. With increasing sample thickness, the conversion at the surface was increased and the oxygen‐affected layer (OAL) decreased, up to a limit where the profiles became independent of the thickness. The addition of a thiol in the acrylate mixture reduced the OAL and the conversion in this region increased. This effect was noticeable even at low concentration of thiol. Real‐time infrared spectroscopy (RT‐FTIR) experiments pointed out that for low thiol content, this beneficial effect is not only attributable to the thiol–ene process—oxygen insensitive—but also to the homopolymerization of acrylates which is enhanced. Homopolymerization and thiyl radical addition were found to have the same impact on the overall mechanism. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Rate‐ and temperature‐dependent strain softening in solid polymers
Authors: van Breemen Lambert C. A. , Engels Tom A. P. , Klompen Edwin T. J. , Senden Dirk J. A. , Govaert Leon E. 
Published: October 2012

AbstractIt is demonstrated that a large number of solid polymers (PMMA, PLLA, iPP, PS) display a pronounced change in kinetics (strain‐rate and temperature dependence) after yield. The phenomenon finds its origin in the fact that, in specific ranges of temperature and strain rate, two different molecular processes may contribute to the yield stress. Because of strain softening, the post‐yield response is only controlled by one of the two, resulting in a strain‐rate dependence of the yield drop. The universality of the phenomenon is discussed in connection to the alleged influence of secondary transitions on the impact response of polymer glasses. A modification of the finite‐strain elasto‐viscoplastic EGP‐model is proposed to enable an accurate description of the mechanical response of solid polymers in the transition range. The versatility of the model is demonstrated on the temperature and strain‐rate dependence of the intrinsic mechanical behavior of PMMA, iPP, PS, and PLLA. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012