bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytocompatibility and osteogenic activity of a novel calcium phosphate silicate bioceramic: Silicocarnotite
Authors: Duan Wei , Ning Congqin , Tang Tingting 
Published: December 2012

AbstractIn the present study, the effect of a novel bioceramic, silicon‐containing calcium phosphate ceramic (silicocarnotite, Ca5(PO4)2SiO4, CPS) on attachment, proliferation, and osteogenic differentiation of rat bone marrow‐derived mesenchymal stem cells (rBMSC) has been investigated in comparison to hydroxyapatite (HA). The CPS showed a similar cell attachment behavior to HA, while the proliferation of rBMSC on CPS was significantly higher than that on HA, which indicated that CPS had a good cytocompatibility. Moreover, the expression of alkaline phosphatase activity and osteogenic‐related genes, including Runx‐2, osteopontin (OPN), bone sialoprotein (BSP) and osteocalcin (OC), demonstrated that CPS enhanced the osteogenic differentiation of rBMSC and accelerated the differentiation process. The results suggest that CPS ceramic exhibits a good cytocompatibility and osteogenic activity, which might be used as a potential candidate material for bone tissue engineering. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Photocrosslinked alginate with hyaluronic acid hydrogels as vehicles for mesenchymal stem cell encapsulation and chondrogenesis
Authors: Coates Emily E. , Riggin Corinne N. , Fisher John P. 
Published: December 2012

AbstractIonic crosslinking of alginate via divalent cations allows for high viability of an encapsulated cell population, and is an effective biomaterial for supporting a spherical chondrocyte morphology. However, such crosslinking chemistry does not allow for injectable and stable hydrogels which are more appropriate for clinical applications. In this study, the addition of methacrylate groups to the alginate polymer chains was utilized so as to allow the free radical polymerization initiated by a photoinitiator during UV light exposure. This approach establishes covalent crosslinks between methacrylate groups instead of the ionic crosslinks formed by the calcium in unmodified alginate. Although this approach has been well described in the literature, there are currently no reports of stem cell differentiation and subsequent chondrocyte gene expression profiles in photocrosslinked alginate. In this study, we demonstrate the utility of photocrosslinked alginate hydrogels containing interpenetrating hyaluronic acid chains to support stem cell chondrogenesis. We report high cell viability and no statistical difference in metabolic activity between mesenchymal stem cells cultured in calcium crosslinked alginate and photocrosslinked alginate for up to 10 days of culture. Furthermore, chondrogenic gene markers are expressed throughout the study, and indicate robust differentiation up to the day 14 time point. At early time points, days 1 and 7, the addition of hyaluronic acid to the photocrosslinked scaffolds upregulates gene markers for both the chondrocyte and the superficial zone chondrocyte phenotype. Taken together, we show that photocrosslinked, injectable alginate shows significant potential as a delivery mechanism for cell‐based cartilage repair therapies. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Parameterization of a geometric flow implicit solvation model
Authors: Thomas Dennis G. , Chun Jaehun , Chen Zhan , Wei Guowei , Baker Nathan A. 
Published: December 2012

AbstractImplicit solvent models are popular for their high computational efficiency and simplicity over explicit solvent models and are extensively used for computing molecular solvation properties. The accuracy of implicit solvent models depends on the geometric description of the solute‐solvent interface and the solvent dielectric profile that is defined near the surface of the solute molecule. Typically, it is assumed that the dielectric profile is spatially homogeneous in the bulk solvent medium and varies sharply across the solute‐solvent interface. However, the specific form of this profile is often described by ad hoc geometric models rather than physical solute‐solvent interactions. Hence, it is of significant interest to improve the accuracy of these implicit solvent models by more realistically defining the solute‐solvent boundary within a continuum setting. Recently, a differential geometry‐based geometric flow solvation model was developed, in which the polar and nonpolar free energies are coupled through a characteristic function that describes a smooth dielectric interface profile across the solvent–solute boundary in a thermodynamically self‐consistent fashion. The main parameters of the model are the solute/solvent dielectric coefficients, solvent pressure on the solute, microscopic surface tension, solvent density, and molecular force‐field parameters. In this work, we investigate how changes in the pressure, surface tension, solute dielectric coefficient, and choice of different force‐field charge and radii parameters affect the prediction accuracy for hydration free energies of 17 small organic molecules based on the geometric flow solvation model. The results of our study provide insights on the parameterization, accuracy, and predictive power of this new implicit solvent model. © 2012 Wiley Periodicals, Inc.
Optimising therapy for schizophrenia and depression: old and new solutions
Authors: Titmarsh Steve 
Published: December 2012

AbstractSchizophrenia and depression were in the spotlight at the Latest Advances in Psychiatry Symposium XI held in London in March 2012. Greater understanding of the mechanisms underlying these diseases are helping clinicians develop strategies that offer hope, particularly to patients who are treatment‐resistant. Steve Titmarsh provides a summary of three of the main lectures at the meeting.
Synthesis of two dihydropyrroloindoledione‐based copolymers for organic electronics
Authors: Rumer Joseph W. , Dai Sheng‐Yao , Levick Matthew , Biniek Laure , Procter David J. , McCulloch Iain 
Published: December 2012

AbstractTwo novel dihydropyrroloindoledione (DPID)‐based copolymers have been synthesized in a two directional approach and characterized (gel permeation chromatography (GPC), ultraviolet‐visible (UV–vis), cyclic voltammetry, and computational models). These planar, broad absorption copolymers show promise for use in organic electronics, with deep energy levels and low bandgaps. The two‐directional Knoevenagel condensation used demonstrates the versatility of DPID as a useful yet underexploited conjugated unit. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Aluminum salen and salan complexes in the ring‐opening polymerization of cyclic esters: Controlled immortal and copolymerization of rac‐β‐butyrolactone and rac‐lactide
Authors: Cross Edward D. , Allan Laura E. N. , Decken Andreas , Shaver Michael P. 
Published: December 2012

AbstractAluminum‐based salen and salan complexes mediate the ring‐opening polymerization (ROP) of rac‐β‐butyrolactone (β‐BL), rac‐lactide, and ε‐caprolactone. Al‐salen and Al‐salan complexes exhibit excellent control over the ROP of rac‐β‐butyrolactone, yielding atactic poly(3‐hydroxybutyrate) (PHB) with narrow PDIs of <1.15 for Al‐salen and <1.05 for Al‐salan. Kinetic studies reveal pseudo‐first‐order polymerization kinetics and a linear relationship between molecular weight and percent conversion. These complexes also mediate the immortal ROP of rac‐β‐BL and rac‐lactide, through the addition of excess benzyl alcohol of up to 50 mol eq., with excellent control observed. A novel methyl/adamantyl‐substituted Al‐salen system further improves control over the ROP of rac‐lactide and rac‐β‐BL, yielding atactic PHB and highly isotactic poly(lactic acid) (Pm = 0.88). Control over the copolymerization of rac‐lactide and rac‐β‐BL was also achieved, yielding poly(lactic acid)‐co‐poly(3‐hydroxybutyrate) with narrow PDIs of <1.10. 1H NMR spectra of the copolymers indicate a strong bias for the insertion of rac‐lactide over rac‐β‐BL. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Thermal stability studies on atomically clean and sulphur passivated InGaAs surfaces
Authors: Chauhan Lalit , Hughes Greg 
Published: December 2012

AbstractHigh resolution synchrotron radiation core level photoemission measurements have been used to study the high temperature stability of sulphur passivated InGaAs surfaces and comparisons made with atomically clean surfaces subjected to the same annealing temperatures. Sulphur passivation of clean InGaAs surfaces prepared by the thermal removal of an arsenic capping layer was carried out using an in situ molecular sulphur treatment in ultra high vacuum. The elemental composition of the surfaces of these materials was measured at a series of annealing temperatures up to 530 °C. Following a 480 °C anneal In:Ga ratio was found to have dropped by 33% on sulphur passivated surface indicating a significant loss of indium, while no drop in indium signal was recorded at this temperature on the atomically InGaAs surface. No significant change in the As surface concentration was measured at this temperature. These results reflect the reduced thermal stability of the sulphur passivated InGaAs compared to the atomically clean surface which has implications for device fabrication.
Mechanism of Si outdiffusion in plasma‐assisted molecular beam epitaxy of GaN on Si
Authors: Adikimenakis A. , Aretouli K. E. , Tsagaraki K. , Kayambaki M. , Georgakilas A. 
Published: December 2012

AbstractThe mechanism of Si outdiffusion related to the formation of Si‐rich GaN clusters during the growth of GaN‐on‐Si by plasma‐assisted molecular beam epitaxy (PAMBE) has been identified. GaN thin films were grown, on high resistivity Si (111) substrates at Ga‐rich conditions to favour the 2D step‐flow growth mode. Hall‐effect measurements revealed very high electron background concentrations, ranging from 2 x 1018 cm‐3 to 3 x 1019 cm‐3, with degraded carrier mobility in the range of 5‐30 cm2/Vs. SEM examination of surfaces and cross‐sections of the samples revealed the presence of hollow GaN clusters on the film surface and voids at the Si/III‐nitride interface. EDX spot analysis revealed dissolution of Si material in the GaN clusters. Growth of GaN on Si under stoichiometric conditions resulted in films without GaN clusters, which exhibited a serious reduction in carrier concentration, down to 1.4 x 1016 cm‐3, with a simultaneous increase of the carrier mobility to 137 cm2/Vs. C‐V carrier profile measurements were consistent with Hall‐effect measurements and revealed a uniform electron concentration in the GaN film, down to the AlN nucleation layer (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray imaging and diffraction study of strain relaxation in MBE grown SiGe/Si layers
Authors: Burle N. , Escoubas S. , Kasper E. , Werner J. , Oehme M. , Lyutovich K. 
Published: December 2012

AbstractMolecular Beam Epitaxy (MBE) grown, 50‐800 nm thick SiGe layers on Si are studied by two X‐ray complementary techniques: imaging (X‐ray topography) and High Resolution X‐Ray Diffraction. The measured relaxation rates are spreding from as low as 0.01% to over 70%. These results are examined through the main models for critical thickness tc calculation, the Matthews and Blakeslee approach concerning misfit dislocations (MD) development from existing dislocations and the People and Bean model for homogeneous MD nucleation.The beginning step of the relaxation is found to fit exactly with the People and Bean model, otherwise larger relaxation is reached after an intermediate weak relaxation stage. This leads to a refined approach of the critical thickness: a critical band [t, t] Comparison between observed t and calculated tc indicates that the lower limit of this band can be predicted by equilibrium models, the upper one being linked with multiplication stages (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transmission electron microscopy analysis of extended defects in multicrystalline silicon using in‐situ EBIC/FIB sample preparation
Authors: Falkenberg M. A. , Seibt M. 
Published: December 2012

AbstractThis paper reports results of microstructural investigations of block cast multicrystalline silicon materials deliberately contaminated with iron and copper impurities from the melt. Electron microscopy techniques have been used to study interactions of grain boundaries, light element impurities such as nitrogen and oxygen, and metal impurities. The key to get access to extended defects typically present in a small density is the recently developed in‐situ EBIC/FIB approach to sample preparation.Special attention is drawn to oxygen and nitrogen containing precipitates at grain boundaries and resulting secondary defects. Strong accumulation of copper impurities is observed which is related to reduced excess carrier lifetimes in these regions. It is shown that copper silicide precipitation mainly accounts for local dislocation networks with a high recombination activity. These observations provide evidence that decoration of grain boundaries with light element contaminants leads to efficient nucleation of metal impurity precipitates. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐born–oppenheimer nuclear and electronic densities for a hooke‐coulomb model for a four‐particle system
Authors: Becerra Marcos , Posligua Víctor , Ludeña Eduardo V. 
Published: December 2012

AbstractBased on the exact solutions for a non‐Born–Oppenheimer (nBO) Hooke‐Coulomb model for a four‐particle system (J. Chem. Phys. 2005, 123, 024102), we present here nBO nuclear and electron one‐particle densities for this system. We examine the effect on the topology of the one‐particle densities that arises from the selection of different reference points for the densities. In addition, we analyze the behavior of these densities as a function of the mass ratio between light and heavy particles. We conclude from these results that molecular structure is not univocally related to the topology of the one‐particle densities in a nBO regime. © 2012 Wiley Periodicals, Inc.
Determination of the Critical Strains for the Initiation of Dynamic Transformation and Dynamic Recrystallization in Four Steels of Increasing Carbon Contents
Authors: Ghosh Chiradeep , Basabe Vladimir V. , Jonas John J. 
Published: December 2012

AbstractHot torsion tests are carried on three plain carbon steels and a Nb microalloyed steel of increasing C concentrations. The tests are performed at strain rates up to 4 s−1 and over the temperature range 743–917°C. The onsets of dynamic transformation (DT) and dynamic recrystallization (DRX) are detected using the double‐differentiation method. Both mechanisms are initiated under all testing conditions but one. The critical strain for DT increases with temperature while the reverse dependency is exhibited by the critical strain for DRX.
What is known about the influence of dentine hypersensitivity on oral health-related quality of life?
Authors: Bekes Katrin , Hirsch Christian 
Published: December 2012

AbstractObjectivesOral health-related quality of life is a relatively new but rapidly growing concept in dentistry. It is an aspect of dental health addressing the patient’s perception of whether his/her current oral health status has an impact upon his/her actual quality of life. Dentine hypersensitivity (DHS), which is a common condition of transient tooth pain associated with a variety of exogenous stimuli, may disturb the patient during eating, drinking, toothbrushing and sometimes even breathing. The resulting restrictions on everyday activities can have an important effect on the patient’s quality of life. The aims of this paper were to consider the concept of oral health-related quality of life and to review and discuss the literature on oral health-related quality of life and DHS.Material and methodsA PubMed literature research was conducted using the terms (“dentin sensitivity” [MeSH Terms] OR (“dentin” [All Fields] AND “sensitivity” [All Fields]) OR “dentin sensitivity” [All Fields]) AND ((“oral health” [MeSH Terms] OR (“oral” [All Fields] AND “health” [All Fields]) OR “oral health” [All Fields]) AND related [All Fields] AND (“quality of life” [MeSH Terms] OR (“quality” [All Fields] AND “life” [All Fields]) OR “quality of life” [All Fields])). Furthermore, a manual search was carried out. Any relevant work published presenting pertinent information about the described issue was considered for inclusion in the review.ResultsThe combination of the search terms resulted in a list of only three titles. The few published studies convincingly demonstrated that oral health-related quality of life is negatively affected in patients suffering from DHS.ConclusionsPatients with sensitive teeth report substantial oral health-related quality of life (OHRQoL) impairment. Nevertheless, knowledge about the influence of DHS on oral health-related quality of life is incomplete and, therefore, needs further research.Clinical relevanceOral diseases can lead to physical, psychological and social disability. This paper shows that DHS can have a negative impact on the patients’ OHRQoL.
Reduced medication use and improved pulmonary function with supplements containing vegetable and fruit concentrate, fish oil and probiotics in asthmatic school children: a randomised controlled trial
Authors: Lee Shu-Chen , Yang Yao-Hsu , Chuang Shao-Yuan , Huang Shih-Yi , Pan Wen-Harn 
Published: December 2012

Dietary pattern changes may be one of the key factors associated with increasing asthma prevalence. Observational studies have found negative associations between fruit, vegetable and fish consumption and risk of asthma. Experimental studies have also shown that probiotics can modulate the immune system. However, each dietary component exhibits a modest effect. The objective of the present study was to investigate the joint effect of multiple beneficial dietary components on asthma. We designed a 16-week school-based double-blind placebo-controlled randomised trial. The supplement group received fruit plus vegetable concentrate, fish oil and probiotics (FVFP supplement), while the control group received placebos. A total of 192 asthmatic children aged 10–12 years were recruited from elementary schools in metropolitan Taipei. Pulmonary function, medication usage, Paediatric Asthma Quality of Life Questionnaire (PAQLQ) score and the Childhood Asthma Control Test score were evaluated at baseline, and at weeks 8 and 16. Compared with the placebo group, the supplement group showed significant improvement in pulmonary function parameters (91 v. 178 ml for forced vital capacity (FVC), 40 v. 107 ml for forced expiratory volume in 1 s (FEV1) and 1·6 v. 4·8 % for FEV1:FVC ratio; all P values < 0·01) and had a significantly reduced proportion of those using short-acting inhaled bronchodilators and inhaled corticosteroids. However, the PAQLQ score and the Childhood Asthma Control Test score were not significantly different between the two groups, possibly because the majority of the children were treated routinely. FVFP supplements reduced medication use and improved pulmonary function in asthmatic children. The present study supports an adjuvant intervention with a combination of fruit, vegetable, fish and probiotic foods.
Nilpotence in group cohomology
Authors: Kuhn Nicholas J. 
Published: December 2012

AbstractWe study bounds on nilpotence in H*(BG), the mod p cohomology of the classifying space of a compact Lie group G. Part of this is a report of our previous work on this problem, updated to reflect the consequences of Peter Symonds's recent verification of Dave Benson's Regularity Conjecture. New results are given for finite p-groups, leading to good bounds on nilpotence in H*(BP) determined by the subgroup structure of the p-group P.
Projecting annual air temperature changes to 2025 and beyond: implications for vegetable production worldwide
Authors: KEATINGE J. D. H. , LEDESMA D. R. , KEATINGE F. J. D. , HUGHES J. D'A. 
Published: December 2012

SUMMARYData sets were accumulated of annual average maximum, minimum and mean air temperature from a range of sites worldwide, specifically from non-urban locations such as agricultural research institutes, universities and other rural or island locations for the period 1975–2011 or longer where data were available. The data sets were then analysed using linear regression to determine the rate and direction of change in temperature over the reference periods. This analysis was performed to provide vegetable scientists with likely future temperature change scenarios up to 2025 and 2050 (on the assumption that recent trends are maintained) so that breeding, agronomic and other related research programmes may better respond to potential challenges from abiotic and biotic stresses to vegetable production. Substantial variation was evident between sites and between time runs at specific sites. At some locations rapid increases in air temperature are projected, such as for sites in East Asia, but at other locations little change is evident; in rare cases, local cooling is shown. The implications of variability and change in air temperature in the context of constraints to vegetable production and the opportunities to exploit the range of genetic diversity available in climatically uncertain environments are discussed. It is believed that modern agricultural science can address successfully the problems raised by climate uncertainty, yet the lack of sufficient, immediate investment in horticultural disciplines worldwide places the world at severe risk of failing to attain effective food and nutritional security.
Host selection by larvae of a marine insectHalocladius variabilis: nutritional dependency or escape from predation?
Authors: Brown Norah E. , Mitchell Sean C. , Garbary David J. 
Published: December 2012

Larvae of the Holarctic marine chironomid,Halocladius variabilis(Staeger), have strong fidelity to the tuft-forming brown alga,Elachista fucicola(Velley) Areschoug, an abundant epiphyte on intertidal fucoids of the North Atlantic. We show that larvae are sufficiently motile to select an algal host in a Petri dish within 3–4 cm, and that larvae show differential behaviour with respect to host selection in the presence or absence of a predator. In the absence of predators 53% of larvae found an algal host within 1 hour; however, after 24 hours, there was no significant difference in host selection. When an isopod predator (Idoteasp.) was present, more larvae found a host within 1 hour (81%) andElachistawas chosen over three of the four other hosts. Furthermore, when larvae were present inElachista, predator (Carcinus maenus) success was significantly reduced relative to two other algal hosts. The adaptive significance ofElachistaas a refuge from predation was confirmed by experiments demonstrating that larval growth with other algal hosts was greater than withElachista. These experiments suggest that microhabitat selection by larvae ofH. variabilisreveals important tradeoffs for growth and predator avoidance.