bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isothermal crystallization kinetics of poly(lactic acid)/synthetic mica nanocomposites
Authors: Souza Diego H. S. , Andrade Cristina T. , Dias Marcos L. 
Published: January 2014

ABSTRACTThe isothermal crystallization kinetics of PLA/fluoromica nanocomposites was studied. Three types of synthetic mica at three concentrations (2.5, 5.0, and 7.5 wt % mica) were used and the effect of these micas on the crystallization and thermal properties of PLA was investigated by differential scanning calorimetry (DSC). The Avrami and Hoffman‐Weeks equations were used to describe the isothermal crystallization kinetics and melting behavior. Addition of these micas to the PLA matrix increased the crystallization rate, and this effect depended on the mica type and concentration. While the nonmodified Somasif ME‐100 exerted the smallest effect, the effect observed for the organically modified Somasif MPE was the most pronounced. The lower half‐time of crystallization t1/2 was around 3 min for the PLA/Somasif MPE nanocomposites containing 7.5 wt % of filler at 90°C, which is about 16 min below that found for neat PLA. The equilibrium melting temperature (
) of PLA were estimated for these systems, showing an increase in the composites and an increase with increasing loading, except for PLA/Somasif MPE, in which the increase of the mica content decreased
about 5°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40322.
Homogenization of natural rubber network induced by nanoclay
Authors: Nie Yijing , Qu Liangliang , Huang Guangsu , Wang Xiaoan , Weng Gengsheng , Wu Jinrong 
Published: January 2014

ABSTRACTVulcanization gives birth to the nonuniformity of rubber network, the identification of which is the basis of improvement of performance of rubber products. We established a visco‐hyperelastic constitutive equation to reveal the quantitative distribution of the inhomogeneous network phases according to a three‐phase model. The cross‐linked network was assumed to be composed of the cross‐linking cluster, the low network chain density domain and the fluid‐like mass. The incorporation of clay with high specific surface area induced the effective uniformity of network structure by decreasing the content of the cross‐linking cluster and increasing that of the low network chain density domain. These structural variations were responsible for excellent mechanical properties and strong strain‐induced crystallization ability probed by the in situ synchrotron wide‐angle X‐ray diffraction. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40324.
Antibacterial and antifungal dressings obtained by photochemical deposition of silver nanoparticles
Authors: Paladini Federica , De Simone Serena , Sannino Alessandro , Pollini Mauro 
Published: January 2014

ABSTRACTThe antimicrobial activity of silver against a wide spectrum of bacteria, fungi and viruses is known since antiquity. Silver has been used as topical antimicrobial agent in the treatment of wounds since many years and advanced silver‐based dressings have been designed so far. The aim of this study was the development of low‐cost antibacterial and antifungal dressings through the surface modification of conventional cotton gauzes. Different percentages of silver were deposited on textile substrates by adopting an innovative silver deposition technique based on the photochemical deposition of silver nanoparticles. The uniformity of the coating and the distribution of the silver clusters on the surface were evaluated by scanning electron microscopy (SEM). The amount of silver was quantified by thermogravimetric analysis (TGA) and the presence of metallic silver nanoparticles was also assesses through UV–Vis–NIR with integrating sphere and energy dispersive X‐ray spectroscopy EDX. The effectiveness of the silver treated textile was verified on different microorganisms, namely Escherichia coli, Staphylococcus aureus, Pseudomonas p43 and Candida albicans derived from a clinical isolate. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40326.
Tough hyperbranched epoxy/poly(amido‐amine) modified bentonite thermosetting nanocomposites
Authors: De Bibekananda , Karak Niranjan 
Published: January 2014

ABSTRACTA tough and highly flexible hyperbranched epoxy and poly(amido‐amine) modified bentonite based thermosetting nanocomposite was demonstrated. The FTIR, XRD, and TGA analyses confirmed the modification of bentonite. The formation of partially exfoliated structure of the nanocomposite with good physicochemical interactions among the hyperbranched epoxy, poly(amido‐amine) hardener and modified clay was investigated by the FTIR, XRD, SEM, and TEM analyses. Significant improvements of 750% toughness, 300% elongation at break, 50% tensile strength, 300% modulus, and 250% adhesive strength of the pristine epoxy were achieved by the formation of nanocomposites with 3 wt % of modified clay. The experimental modulus values of the nanocomposites were compared with three theoretical models to account the interactions between filler and matrix. Thus, the studied epoxy nanocomposite has great potential to be used as an advanced epoxy thermoset. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40327.
Characterization of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) biosynthesized by mixed microbial consortia fed fermented dairy manure
Authors: Wei Liqing , Guho Nicholas M. , Coats Erik R. , McDonald Armando G. 
Published: January 2014

ABSTRACTThe bioplastic poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV), was isolated from a bioreactor using mixed microbial consortia fed volatile fatty acids (VFA), from fermented dairy manure, as the carbon source. The molar fraction of 3‐hydroxyvalerate (3HV) amounted to 0.33 mol mol−1 for two isolated PHBV samples as determined by GC‐MS and 1H‐NMR spectroscopy. The chemical, thermal, and mechanical properties were determined. The PHBVs had relatively high Mw (∼790,000 g mol−1). Only a single glass transition temperature (Tg) and melting point (Tm) were observed. Isolated PHBVs exhibited good flexibility and elongation to break as compared with commercial PHBVs with lower HV. The diad and triad sequence distributions of the monomeric units were determined by 13C‐NMR spectroscopy and followed Bernoullian statistics suggesting that the PHBVs were random. The PHBV sequence distribution was also characterized by electrospray ionization‐mass spectrometry (ESI‐MSn) after partial alkaline hydrolysis to oligomers showing a random 3HV distribution. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40333.
Crosslinked PVA nanofibers reinforced with cellulose nanocrystals: Water interactions and thermomechanical properties
Authors: Peresin Maria Soledad , Vesterinen Arja‐Helena , Habibi Youssef , Johansson Leena‐Sisko , Pawlak Joel J. , Nevzorov Alexander A. , Rojas Orlando J. 
Published: January 2014

ABSTRACTAcid‐catalyzed vapor phase esterification with maleic anhydride was used to improve the integrity and thermo‐mechanical properties of fiber webs based on poly(vinyl alcohol), PVA. The fibers were produced by electrospinning PVA from aqueous dispersions containing cellulose nanocrystals (CNCs). The effect of esterification and CNC loading on the structure and solvent resistance of the electrospun fibers was investigated. Chemical characterization of the fibers (FTIR, NMR) indicated the formation of ester bonds between hydroxyl groups belonging to neighboring molecules. Thermomechanical properties after chemical modification were analyzed using thermal gravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. An 80% improvement in the ultimate strength was achieved for CNC‐loaded, crosslinked PVA fiber webs measured at 90% air relative humidity. Besides the ultra‐high surface area, the composite PVA fiber webs were water resistant and presented excellent mechanical properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40334.
Influence of the degree of crosslinking on the stringiness of crosslinked polyacrylic pressure‐sensitive adhesives
Authors: Ito Keiko , Shitajima Kohei , Karyu Nozomi , Fujii Syuji , Nakamura Yoshinobu , Urahama Yoshiaki 
Published: January 2014

ABSTRACTThe stringiness of crosslinked polyacrylic pressure‐sensitive adhesive (PSA) was observed during 90° peeling under the constant peel load. The random copolymer of butyl acrylate with 5 wt % acrylic acid crosslinked by N,N,N′,N′‐tetraglycidyl‐m‐xylenediamine was used as PSA. All observed stringiness upon peeling was sawtooth‐shaped, but it could be classified into three types dependent on the degree of crosslinking. The typical sawtooth‐shaped stringiness with interfacial failure was observed at the relatively higher crosslinker content ranging from 0.008 to 0.016 chemical equivalents (Eq.), where the PSA has high cohesive strength and low interfacial adhesion. The frame formed at the front end of stringiness at the content ranging from 0.002 to 0.004 Eq. Sufficient interfacial adhesion and deformability generate large internal deformation of the PSA layer. Internal deformation occurred preferentially over peeling as a result of front frame formation. The mode of peeling was changed from cohesive failure to interfacial failure in this range of crosslinker content. The sawtooth‐shaped with cohesive failure was observed at the lower content ranging from 0 to 0.001 Eq. The PSA has high interfacial adhesion and low cohesive strength, and thus exhibited cohesive failure. The PSA after peeling remained in the shape of belts. It was found that the shape of stringiness is strongly dependent on the balance between the interfacial adhesion and the cohesive strength of PSA. When the sawtooth‐shaped stringiness with frame formed, the peeling rate was lowest. This means the peel strength should be the maximum in this shape of stringiness. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40336.
Synthetic small intestinal scaffolds for improved studies of intestinal differentiation
Authors: Costello Cait M. , Hongpeng Jia , Shaffiey Shahab , Yu Jiajie , Jain Nina K. , Hackam David , March John C. 
Published: January 2014

ABSTRACTIn vitro intestinal models can provide new insights into small intestinal function, including cellular growth and proliferation mechanisms, drug absorption capabilities, and host‐microbial interactions. These models are typically formed with cells cultured on 2D scaffolds or transwell inserts, but it is widely understood that epithelial cells cultured in 3D environments exhibit different phenotypes that are more reflective of native tissue. Our focus was to develop a porous, synthetic 3D tissue scaffold with villous features that could support the culture of epithelial cell types to mimic the natural microenvironment of the small intestine. We demonstrated that our scaffold could support the co‐culture of Caco‐2 cells with a mucus‐producing cell line, HT29‐MTX, as well as small intestinal crypts from mice for extended periods. By recreating the surface topography with accurately sized intestinal villi, we enable cellular differentiation along the villous axis in a similar manner to native intestines. In addition, we show that the biochemical microenvironments of the intestine can be further simulated via a combination of apical and basolateral feeding of intestinal cell types cultured on the 3D models. Biotechnol. Bioeng. 2014;111: 1222–1232. © 2014 Wiley Periodicals, Inc.
Psychological care of caregivers, nurses and physicians: a study of a new approach
Authors: Abeni Maurizio S. , Magni Margherita , Conte Martina , Mangiacavalli Silvia , Pochintesta Lara , Vicenzi Gaia , Ferretti Virginia V. , Pompa Alessandra , Cocito Federica , Klersy Catherine , Corso Alessandro 
Published: January 2014

AbstractThere is much evidence demonstrating that psychosocial interventions in caregivers and oncological staff produce an improvement in their patients' quality of life. The aim of this explorative study was to evaluate the effect of a new approach in promoting more functional ways to face stressful situations in the constellation of people around patients: caregivers, physicians and nurses. Thirty‐four subjects were divided into three groups: 10 caregivers, 11 physicians, and 13 nurses. A “Balint Group” method modified according to a mindfulness technique was used as the intervention. Three assessment tools were administered to the participants at baseline, during, and after completion of the study: the Response Evaluation Measure (REM‐71), the Satisfaction Profile (SAT‐P), and the Group Climate Questionnaire (GCQ). Mean values of defense mechanisms determined by the REM‐71 were compared with those of the standard population. At baseline, we observed a prevalence of immature defenses in the three groups, with mean values above those in the standard population. After the psychological intervention, a tendency to normalization of the mean values was observed, indicating the development of more adaptive ways of using defense mechanisms and the effectiveness of the intervention. Group climate, assessed through the GCQ, showed an increase in the “Engagement” factor and a decline in the “Conflict” factor in all groups. This study suggests that group treatment focused on changing personal responses to stressful situations can induce more adaptive strategies enabling caregivers, hematologists, and nurses to help patients better and thereby improve their quality of life.
Interaction of DHPG‐LTD and synaptic‐LTD at senescent CA3‐CA1 hippocampal synapses
Authors: Kumar Ashok , Foster Thomas C. 
Published: January 2014

ABSTRACTThe susceptibility, but not the magnitude, of long‐term depression (LTD) induced by hippocampal CA3‐CA1 synaptic activity (synaptic‐LTD) increases with advanced age. In contrast, the magnitude of LTD induced by pharmacological activation of CA3‐CA1 group I metabotropic glutamate receptors (mGluRs) increases during aging. This study examined the signaling pathways involved in induction of LTD and the interaction between paired‐pulse low frequency stimulation‐induced synaptic‐LTD and group I mGluR selective agonist, (RS)‐3,5‐dihydroxyphenylglycine (DHPG, 100 µM)‐induced DHPG‐LTD in hippocampal slices obtained from aged (22–24 months) male Fischer 344 rats. Prior induction of synaptic‐LTD did not affect induction of DHPG‐LTD; however, prior induction of the DHPG‐LTD occluded synaptic‐LTD suggesting that expression of DHPG‐LTD may incorporate synaptic‐LTD mechanisms. Application of individual antagonist for the group I mGluR (AIDA), the N‐methyl‐d‐aspartate receptor (NMDAR) (AP‐5), or L‐type voltage‐dependent Ca2+ channel (VDCC) (nifedipine) failed to block synaptic‐LTD and any two antagonists severely impaired synaptic‐LTD induction, indicating that activation of any two mechanisms is sufficient to induce synaptic‐LTD in aged animals. For DHPG‐LTD, AIDA blocked DHPG‐LTD and individually applied NMDAR or VDCC attenuated but did not block DHPG‐LTD, indicating that the magnitude of DHPG‐LTD depends on all three mechanisms. © 2014 Wiley Periodicals, Inc.
Effect of grip type, wrist motion, and resistance level on pressures within the carpal tunnel of normal wrists
Authors: McGorry Raymond W. , Fallentin Nils , Andersen Johan H. , Keir Peter J. , Hansen Torben B. , Pransky Glenn , Lin Jia‐Hua 
Published: January 2014

ABSTRACTElevated carpal tunnel pressure (CTP) has been associated with carpal tunnel syndrome. This study systematically evaluated the effect of wrist motion resistance and grip type on CTP during wrist motion typical of occupational tasks. CTP during four wrist motion patterns, with and without resistance, and with and without gripping, was measured in vivo in 14 healthy individuals. CTP measured during compound motions fell between that measured in the cardinal planes of wrist flexion/extension and radial/ulnar deviation. Generally, with no active gripping there was little pressure change due to wrist angular displacement or resistance level. However, concurrent active pinch or power grip increased CTP particularly in motions including extension. CTP typically did not increase during wrist flexion, and in fact often decreased. Extension motions against resistance when employing a pinch or power grip increase CTP more than motions with flexion. Results could help inform design or modification of wrist motion intensive occupational tasks. © 2014 The Authors. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:524–530, 2014.
Improving outcomes for posterolateral knee injuries
Authors: LaPrade Robert F. , Griffith Chad J. , Coobs Benjamin R. , Geeslin Andrew G. , Johansen Steinar , Engebretsen Lars 
Published: January 2014

ABSTRACTUntil recently, the posterolateral corner of the knee was noted both for its complex anatomy and diagnostic challenges. To improve the understanding of the posterolateral knee, we completed a comprehensive and stepwise research program with a focus on five primary areas: (1) surgical approach and relevant anatomy; (2) diagnosis; (3) clinically relevant biomechanics; (4) natural history; and (5) surgical treatment. Based on this comprehensive research program, the diagnosis and outcomes following treatment of posterolateral knee injuries have been significantly improved comparing the preoperative state to the state of the knee at a minimum 2 year follow‐up in the cases series presented here. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:485–491, 2014.
In situ label‐free cell viability assessment of nucleus pulposus tissue
Authors: Dittmar Roman , van Dijk Bart G. M. , van Zandvoort Marc A. M. J. , Ito Keita 
Published: January 2014

ABSTRACTRegenerative medicine approaches aiming at treating degenerating intervertebral discs, a major cause of back pain, are increasingly tested in ex‐vivo disc explant models mimicking in‐vivo conditions. For assessing the efficacy of regenerative therapies, cell viability is commonly measured requiring specific labels to stain cells. Here, we demonstrate and evaluate how cellular auto‐fluorescence can be utilized to non‐invasively assess viability in disc tissue in‐situ using label‐free two‐photon microscopy. Live and dead bovine disc cells (0% and 100% cell viability) from the nucleus pulposus were seeded into collagen gels and auto‐fluorescence was characterized. Subsequently, nucleus pulposus explants were cultured for 6 days in media with different glucose supplementation (0, 0.25, 0.5, and 1 g/L) to induce different degrees of cell death. Then, samples were split and viability was assessed using label‐free two‐photon microscopy and conventional staining. Results show that live and dead nucleus pulposus cells systematically emit auto‐fluorescent light with distinct characteristics. Cell viability values obtained with label‐free microscopy did not significantly differ from those acquired with staining. In summary, monitoring auto‐fluorescence facilitates accurate cell viability assessment in nucleus tissue requiring no additional dyes. Thus, this technique may be suitable for pre‐clinical testing of regenerative therapies in nucleus pulposus cultures. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:545–550, 2014.
Src activity is increased in gastrointestinal stromal tumors—Analysis of associations with clinical and other molecular tumor characteristics
Authors: Rotert Julia Valerie , Leupold Jörg , Hohenberger Peter , Nowak Kai , Allgayer Heike 
Published: January 2014

ABSTRACTBackgroundIncreased activity of Src has been found in several human cancers, and often is associated with poor clinical outcome. The present study aimed to determine whether Src activity is increased in gastrointestinal stromal tumors (GIST), and whether it correlates with established tumor or patient characteristics and prognosis.MethodsTumor/normal tissues of 29 patients were analyzed for Src activity/protein with kinase assays, and for VEGF/VEGFR with immunohistochemical staining.ResultsSrc activity was higher in tumor than in normal tissues (P = 0.093). However, when imatinib responders were excluded from the analyses, it was significantly higher in the tumor tissue (P = 0.017). Additionally, it was higher in primary compared to recurrent tumors or metastasis (P = 0.04). Univariate survival analysis showed a longer overall survival for patients with high Src activity (P = 0.038). In multivariate analysis, the response to imatinib treatment was the only survival‐influencing factor (P = 0.072).ConclusionsSrc activity is increased in GIST. In contrast to most other tumor entities, it does not correlate with poor clinical outcome, but decreases during the progression from primary tumor to recurrence and metastasis, especially under therapy with imatinib. Additionally, our results show that higher Src activity is associated with longer overall survival. J. Surg. Oncol. 2014 109:597–605. © 2014 Wiley Periodicals, Inc.
National trends in surgery for sinonasal malignancy and the effect of hospital volume on short‐term outcomes
Authors: Ouyang David , El‐Sayed Ivan H. , Yom Sue S. 
Published: January 2014

Objectives/HypothesisTo characterize trends in the management of sinonasal malignancy with a focus on the impact of hospital volume on surgical outcomes.Study DesignRetrospective cohort study.MethodsTime trends were analyzed among patients admitted for surgical resection of sinonasal malignancy in the Nationwide Inpatient Sample (NIS) between 1988 and 2009. Subset analysis was performed on cohorts with skull base or orbital involvement or on cohorts who underwent neck dissection. Patient characteristics and hospital attributes were correlated with morbidity and mortality.ResultsOver 22 years, we identified 3,850 cases from 879 hospitals. A total of 24.3% of patients had complications and 0.8% of hospitalizations resulted in mortality. Cases with skull base or orbital involvement, or cases including neck dissection, had more complications and a longer length of stay. Prevalence of neck dissection increased over time.Thirty‐two hospitals averaged more than five cases per year, accounting for 28% of all surgeries. These centers were large (73.3%), urban (96.7%), teaching (90%) institutions and performed more high‐risk cases: 32.4% of neck dissections, 44.6% of orbital cases, and 43.1% of skull base cases. Compared to lower‐volume centers, these centers had more cardiopulmonary and electrolyte complications, but no difference was observed in the lengths of stay. A greater proportion of cases were recently performed at high‐volume centers.ConclusionOver time, complicated surgeries were more likely to occur at higher‐volume hospitals without significant changes in surgical complication rates. High‐volume centers had increased rates of cardiopulmonary and electrolyte complications, likely representing complex postoperative management, but these were not associated with higher mortality.Level of Evidence2c. Laryngoscope, 124:1609–1614, 2014