bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of the biocompatibility of two novel, bionanocomposite scaffolds in a rodent model
Authors: Deeken C. R. , Esebua M. , Bachman S. L. , Ramshaw B. J. , Grant S. A. 
Published: January 2011

AbstractTwo novel, bionanocomposite scaffolds were evaluated in a rodent model over the course of three months to determine whether these scaffolds possessed adequate biocompatibility characteristics to warrant further evaluation as possible tissue reconstruction scaffolds. These bionanocomposite scaffolds were comprised of amine‐functionalized gold nanoparticles (AuNP) or silicon carbide nanowires (SiCNW) crosslinked to an acellular porcine diaphragm tendon. It was hypothesized that the addition of nanomaterials to the porcine tendon would also improve its biocompatibility by imparting a nanostructured surface. As early as seven days after implantation, both types of bionanocomposite scaffolds displayed evidence of granulation tissue and the beginning of scaffold remodeling with new collagen deposited by the host, and by ninety‐seven days the bionanocomposite scaffolds were completely remodeled with no evidence of any adverse host tissue reaction or scar tissue formation. The AuNP bionanocomposite scaffolds exhibited accelerated scaffold remodeling compared to the SiCNW scaffolds. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
A 3D numerical simulation of stress distribution and fracture process in a zirconia‐based FPD framework
Authors: Kou Wen , Li Decong , Qiao Jiyan , Chen Li , Ding Yansheng , Sjögren Göran 
Published: January 2011

AbstractIn this study, a numerical approach to the fracture behavior in a three‐unit zirconia‐based fixed partial denture (FPD) framework was made under mechanical loading using a newly developed three‐dimensional (3D) numerical modeling code. All the materials studied were treated heterogeneously and Weibull distribution law was applied to describe the heterogeneity. The Mohr‐Coulomb failure criterion with tensile strength cut‐off was utilized to judge whether the material was in an elastic or failed state. For validation, the fracture pattern obtained from the numerical modeling was compared with a laboratory test; they largely correlated with each other. Similar fracture initiation sites were detected both in the numerical simulation and in an earlier fractographic analysis. The numerical simulation applied in this study clearly described the stress distribution and fracture process of zirconia‐based FPD frameworks, information that could not be gained from the laboratory tests alone. Thus, the newly developed 3D numerical modeling code seems to be an efficient tool for prediction of the fracture process in ceramic FPD frameworks. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Efficiency of alchemical free energy simulations. II. Improvements for thermodynamic integration
Authors: Bruckner Stefan , Boresch Stefan 
Published: December 2010

AbstractWe attempt to optimize the efficiency of thermodynamic integration, as defined by the minimal number of unphysical intermediate states required for the computation of accurate and precise free energy differences. The suitability of various numerical quadrature methods is tested. In particular, we compare the trapezoidal rule, Simpson's rule, Gauss‐Legendre, Gauss‐Kronrod‐Patterson, and Clenshaw‐Curtis integration, as well as integration based on a cubic spline approximation of the integrand. We find that Simpson's rule and spline integration are already significantly more efficient that the trapezoidal rule, i.e., correct free energy differences can be obtained using fewer λ‐states. We demonstrate that Simpson's rule can be used advantageously with nonequidistant values of the abscissa, which increases the flexibility of the method. Efficiency is enhanced even further if higher order methods, such as Gauss‐Legendre, Gauss‐Kronrod‐Patterson, or Clenshaw‐Curtis integration, are used; no more than seven λ‐states, which in the case of Clenshaw‐Curtis integration include the physical end states, were required for accurate results in all test problems studied. Thus, the performance of thermodynamic integration can equal that of Bennett's acceptance ratio method. We also show, however, that the high efficiency found here relies on the particular functional form of the soft‐core potential used; overall, thermodynamic integration is more susceptible to the details of the hybrid Hamiltonian used than Bennett's acceptance ratio method. Therefore, we recommend Bennett's acceptance ratio method as the most robust method to compute alchemical free energy differences; nevertheless, scenarios when thermodynamic integration may be preferable are discussed. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
Combination of the CHARMM27 force field with united‐atom lipid force fields
Authors: Sapay Nicolas , Tieleman D. Peter 
Published: December 2010

AbstractComputer simulations offer a valuable way to study membrane systems, from simple lipid bilayers to large transmembrane protein complexes and lipid‐nucleic acid complexes for drug delivery. Their accuracy depends on the quality of the force field parameters used to describe the components of a particular system. We have implemented the widely used CHARMM22 and CHARMM27 force fields in the GROMACS simulation package to (i) combine the CHARMM22 protein force field with two sets of united‐atom lipids parameters; (ii) allow comparisons of the lipid CHARMM27 force field with other lipid force fields or lipid‐protein force field combinations. Our tests do not show any particular issue with the combination of the all‐atom CHARMM22 force field with united‐atoms lipid parameters, although pertinent experimental data are lacking to assess the quality of the lipid‐protein interactions. The conversion utilities allow automatic generation of GROMACS simulation files with CHARMM nucleic acids and protein parameters and topologies, starting from pdb files using the standard GROMACS pdb2gmx method. CMAP is currently not implemented. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
Regional differences in hyoid muscle activity and length dynamics during mammalian head shaking
Authors: Wentzel Sarah E. , Konow Nicolai , German Rebecca Z. 
Published: December 2010

AbstractThe sternohyoid (SH) and geniohyoid (GH) are antagonist strap muscles that are active during a number of different behaviors, including sucking, intraoral transport, swallowing, breathing, and extension/flexion of the neck. Because these muscles have served different functions through the evolutionary history of vertebrates, it is quite likely they will have complex patterns of electrical activity and muscle fiber contraction. Different regions of the SH exhibit different contraction and activity patterns during a swallow. We examined the dynamics of the SH and GH muscles during an unrestrained, and vigorous head shaking behavior in an animal model of human head, neck, and hyolingual movement. A gentle touch to infant pig ears elicited a head shake of several revolutions. Using sonomicrometry and intramuscular EMG, we measured regional (within) muscle strain and activity in SH and GH. We found that EMG was consistent across three regions (anterior, belly, and posterior) of each muscle. Changes in muscle length, however, were more complex. In the SH, mid‐belly length‐change occurred out‐of‐phase with the anterior and posterior end regions, but with a zero lag timing; the anterior region shortened before the posterior. In the GH, the anterior region shortened before and out‐of‐phase with the mid‐belly and posterior regions. Head shaking is a relatively simple reflex behavior, yet the underlying patterns of muscle length dynamics and EMG activity are not. The regional complexity in SH and GH, similar to regionalization of SH during swallowing, suggests that these anatomically simple hyoid strap muscles have more complex function than textbooks often suggest. J. Exp. Zool. 315:111–120, 2011. © 2010 Wiley‐Liss, Inc.
Temperature affects brain and pituitary gene expression related to reproduction and growth in the male blue gouramis, Trichogaster trichopterus
Authors: David Dalia , Degani Gad 
Published: December 2010

AbstractThis study examined the effect of temperature on reproduction and growth‐related factors in blue gourami males under nonreproductive and reproductive conditions. Males that were maintained under nonreproductive conditions did not build nest and the gonado‐somatic index (% GSI) was significantly higher in fish maintained at 27°C compared with fish maintained at 23°C. The relative mRNA levels of brain gonadotropin‐releasing hormone 3 (GnRH3), pituitary adenylate cyclase‐activating polypeptide (PACAP), insulin‐like growth factor‐1(IGF‐1), pituitary β‐luteinizing hormone (βLH), and prolactin were significantly higher when the fish were maintained at 27°C than at 23°C or 31°C. β‐Follicle‐stimulating hormone (βFSH) mRNA levels were significantly lower when maintained at 31°C than at the other temperatures. Nests were observed only in males under reproductive conditions. In these fish, higher mRNA levels of GnRH3, PACAP, βFSH, βLH and prolactin were detected at 27°C, and higher mRNA levels of IGF‐1 were detected at 23°C, when compared with other temperature of maintenance or with fish that did not build nest. In conclusion, we propose that temperature has more effect on the transcription of genes, associated with reproduction, than on those pertaining to growth. J. Exp. Zool. 315A:203–214, 2011. © 2011 Wiley‐Liss, Inc.
New insights on ctenophore neural anatomy: Immunofluorescence study in Pleurobrachia pileus (Müller, 1776)
Authors: Jager Muriel , Chiori Roxane , Alié Alexandre , Dayraud Cyrielle , Quéinnec Eric , Manuel Michaël 
Published: December 2010

AbstractCtenophores are non‐bilaterian animals sharing with cnidarians and bilaterians the presence of sensory receptors, nerve cells, and synapses, absent in placozoans and sponges. Although recent immunofluorescence studies have renewed our knowledge of cnidarian neuro‐anatomy, ctenophores have been much less investigated despite their importance to understanding the origin and early evolution of the nervous system. In this study, the neuro‐anatomy of the ctenophore Pleurobrachia pileus (Müller, 1776) was explored by whole‐mount fluorescent antibody staining using antibodies against tyrosylated α‐tubulin, FMRFamide, and vasopressin. We describe the morphology of nerve nets and their local specializations, and the organization of the aboral neuro‐sensory complex comprising the apical organ and polar fields. Two distinct nerve nets are distinguished: a mesogleal nerve net, loosely organized throughout body mesoglea, and a much more compact “nerve net” with polygonal meshes in the ectodermal epithelium. The latter is organized as a plexus of short nerve cords. This epithelial nervous system contains distinct sub‐populations of dispersed FMRFamide and vasopressin immunoreactive nerve cells. In the aboral neuro‐sensory complex, our most significant observations include specialized nerve nets underlying the apical organ and polar fields, a tangential bundle of actin‐rich fibers (interpreted as a muscle) within the polar fields, and distinct groups of neurons labeled by anti‐FMRFamide and anti‐vasopressin antibodies, within the apical organ floor. These results are discussed in a comparative perspective. J. Exp. Zool. (Mol. Dev. Evol.) 316:171–187, 2011. © 2010 Wiley‐Liss, Inc.
Aging and training and development willingness: Employee and supervisor mindsets
Authors: Van Vianen Annelies E. M. , Dalhoeven Betty A. G. W. , De Pater Irene E. 
Published: January 2011

AbstractIn this study, we examined individual and situational factors that impact the relationship between age and employee training and development willingness. We proposed that the relationship between age and training and development willingness would be moderated by employees' entity self‐theory and perceived developmental support. Furthermore, we investigated supervisors' beliefs about the avoidance orientations of older employees and whether these beliefs would moderate the relationship between employee age and training and development willingness. The proposed moderation effects were found. Moreover, it was shown that entity self‐theory beliefs, perceived developmental support, and supervisor avoidance orientation beliefs were related to the training and development willingness of older subordinates. Copyright © 2010 John Wiley & Sons, Ltd.
Screening for fetal aneuploidies at 11 to 13 weeks
Authors: Nicolaides Kypros H. 
Published: January 2011

AbstractEffective screening for major aneuploidies can be provided in the first trimester of pregnancy. Screening by a combination of fetal nuchal translucency and maternal serum free‐β‐human chorionic gonadotrophin and pregnancy‐associated plasma protein‐A can identify about 90% of fetuses with trisomy 21 and other major aneuploidies for a false‐positive rate of 5%. Improvement in the performance of first‐trimester screening can be achieved by firstly, inclusion in the ultrasound examination assessment of the nasal bone and flow in the ductus venosus, hepatic artery and across the tricuspid valve, and secondly, carrying out the biochemical test at 9 to 10 weeks and the ultrasound scan at 12 weeks. Copyright © 2011 John Wiley & Sons, Ltd.
Challenges in the diagnosis of fetal non‐chromosomal abnormalities at 11–13 weeks
Authors: Syngelaki Argyro , Chelemen Teodora , Dagklis Themistoklis , Allan Lindsey , Nicolaides Kypros H. 
Published: January 2011

AbstractObjectiveTo examine the performance of the 11–13 weeks scan in detecting non‐chromosomal abnormalities.MethodsProspective first‐trimester screening study for aneuploidies, including basic examination of the fetal anatomy, in 45 191 pregnancies. Findings were compared to those at 20–23 weeks and postnatal examination.ResultsAneuploidies (n = 332) were excluded from the analysis. Fetal abnormalities were observed in 488 (1.1%) of the remaining 44 859 cases; 213 (43.6%) of these were detected at 11–13 weeks. The early scan detected all cases of acrania, alobar holoprosencephaly, exomphalos, gastroschisis, megacystis and body stalk anomaly, 77% of absent hand or foot, 50% of diaphragmatic hernia, 50% of lethal skeletal dysplasias, 60% of polydactyly, 34% of major cardiac defects, 5% of facial clefts and 14% of open spina bifida, but none of agenesis of the corpus callosum, cerebellar or vermian hypoplasia, echogenic lung lesions, bowel obstruction, most renal defects or talipes. Nuchal translucency (NT) was above the 95th percentile in 34% of fetuses with major cardiac defects.ConclusionAt 11–13 weeks some abnormalities are always detectable, some can never be and others are potentially detectable depending on their association with increased NT, the phenotypic expression of the abnormality with gestation and the objectives set for such a scan. Copyright © 2011 John Wiley & Sons, Ltd.
Prediction of miscarriage and stillbirth at 11–13 weeks and the contribution of chorionic villus sampling
Authors: Akolekar Ranjit , Bower Sarah , Flack Nicola , Bilardo Caterina M. , Nicolaides Kypros H. 
Published: January 2011

AbstractObjectivesTo derive models for estimating risk of miscarriage and stillbirth from maternal characteristics and findings of first‐trimester screening for aneuploidies and to define the procedure‐related risk of chorionic villus sampling (CVS) after adjusting for these factors.MethodWe examined 33 856 singleton pregnancies at 11+0 to 13+6 weeks, and in 2396 CVS was carried out. Logistic regression analysis was used to examine the factors contributing to miscarriage and stillbirth.ResultsThere were 33 310 (98.4%) livebirths, 404 (1.2%) miscarriages and 142 (0.4%) stillbirths. Models combining maternal characteristics, nuchal translucency, pregnancy‐associated plasma protein‐A (PAPP‐A) and flow in the ductus venosus detected 36.9% of miscarriages and 35.2% of stillbirths, at a 10% false‐positive rate. The risk of miscarriage and stillbirth increased with maternal age and weight, in women of African racial origin, in those with previous miscarriages or stillbirths and in those with low serum PAPP‐A and reversed A‐wave in the ductus venosus. The risk of miscarriage increased in women with pre‐existing diabetes mellitus, in those conceiving on ovulation‐induction drugs and in those with high fetal nuchal translucency, and the risk of stillbirth increased in women with chronic hypertension and in cigarette smokers. The expected number of miscarriages and stillbirths in the CVS group and the models derived from the non‐CVS group were 45 (95% prediction intervals 32–58) and 18 (95% prediction intervals 9–26), respectively. These expected numbers were not significantly different from the observed 44 and 15 cases (p = 0.881 and 0.480), respectively.ConclusionA high proportion of fetal losses can be predicted at 11 to 13 weeks. A model for such predictions can be used to assess the procedure‐related risks from CVS. Copyright © 2011 John Wiley & Sons, Ltd.
Prediction of spontaneous preterm delivery from maternal factors, obstetric history and placental perfusion and function at 11–13 weeks
Authors: Beta Jarek , Akolekar Ranjit , Ventura Walter , Syngelaki Argyro , Nicolaides Kypros H. 
Published: January 2011

AbstractObjectiveTo develop a model for prediction of spontaneous delivery before 34 weeks based on maternal factors, placental perfusion and function at 11–13 weeks' gestation.MethodsTwo groups of studies: first, screening study of maternal characteristics, serum pregnancy‐associated plasma protein‐A (PAPP‐A), free β‐human chorionic gonadotrophin (β‐hCG) and uterine artery pulsatility index (PI). Second, case‐control studies of maternal serum or plasma concentration of placental growth factor (PlGF), placental protein 13 (PP13), a disintegrin and metalloprotease 12 (ADAM12), inhibin‐A and activin‐A. Regression analysis was used to develop a model for the prediction of spontaneous early delivery.ResultsSpontaneous early delivery occurred in 365 (1.1%) of the 34 025 pregnancies. A model based on maternal factors could detect 38.2% of the preterm deliveries in women with previous pregnancies at or beyond 16 weeks and 18.4% in those without, at a false positive rate (FPR) of 10%. In the preterm delivery group, compared with unaffected pregnancies there were no significant differences in the markers of placental perfusion or function, except for PAPP‐A which was reduced.ConclusionsPatient‐specific risk of preterm delivery is provided by maternal factors and obstetric history. Placental perfusion and function at 11–13 weeks are not altered in pregnancies resulting in spontaneous early delivery. Copyright © 2011 John Wiley & Sons, Ltd.
Interstitial iron concentrations across multicrystalline silicon wafers via photoluminescence imaging
Authors: Liu AnYao , Fan Yang‐Chieh , Macdonald Daniel 
Published: January 2011

AbstractWe present high‐resolution images of the lateral distribution of interstitial iron across wafers from various positions along the length of a directionally solidified multicrystalline silicon ingot. Iron images were taken on wafers in the as‐cut state and also after two different phosphorus gettering steps performed at 845°C for 30 min, one with an additional anneal at 600°C for 5 h (referred to as extended gettering). The iron images were obtained by taking calibrated photoluminescence (PL) images of the low injection carrier lifetimes, before and after dissociation of iron–boron pairs via strong illumination. The iron images clearly reveal the internal gettering of iron during ingot cooling to grain boundaries and dislocation clusters, resulting in much lower dissolved iron concentrations at those features. In contrast, the PL images of gettered wafers exhibit a reversed distribution of dissolved iron compared to the as‐cut wafers, in other words, with higher interstitial iron concentrations at the grain boundaries than within the grains, most probably owing to the precipitated iron at the grain boundaries partly dissolving during the high‐temperature gettering process. Phosphorus gettering was found to result in a significant reduction of interstitial iron both inside the grains and at grain boundaries. The extended gettering resulted in a further significant reduction in all parts of the wafers and along all sections of the ingot. Copyright © 2011 John Wiley & Sons, Ltd.
Clinical observational gait analysis to evaluate improvement of balance during gait with vibrotactile biofeedback
Authors: Janssen Maurice , Pas Rianne , Aarts Jos , Janssen‐Potten Yvonne , Vles Hans , Nabuurs Christine , van Lummel Rob , Stokroos Robert , Kingma Herman 
Published: January 2011

AbstractBackground and Purpose. This study explores the effect of vibrotactile biofeedback on gait in 20 patients with bilateral vestibular areflexia using observational gait analysis to score individual balance. Methods. A tilt sensor mounted on the head or trunk is used to detect head or body tilt and activates, via a microprocessor, 12 equally distributed vibrators placed around the waist. Two positions of the tilt sensor were evaluated besides no biofeedback in three different gait velocity tasks (slow/fast tandem gait, normal gait on foam) resulting in nine different randomized conditions. Biofeedback activated versus inactivated was compared. Twenty patients (10 males, 10 females, age 39–77 years) with a bilateral vestibular areflexia or severe bilateral vestibular hyporeflexia, severe balance problems and frequent falls participated in this study. Results. Significant improvements in balance during gait were shown in our patients using biofeedback and sensor on the trunk. Only two patients showed a significant individual gait improvement with the biofeedback system, but in the majority of our patients, it increased confidence and a feeling of balance. Conclusion. This study indicates the feasibility of vibrotactile biofeedback for vestibular rehabilitation and to improve balance during gait. Copyright © 2011 John Wiley & Sons, Ltd.
Influenza A virus infection kinetics: quantitative data and models
Authors: Smith Amber M. , Perelson Alan S. 
Published: December 2010

AbstractInfluenza A virus is an important respiratory pathogen that poses a considerable threat to public health each year during seasonal epidemics and even more so when a pandemic strain emerges. Understanding the mechanisms involved in controlling an influenza infection within a host is important and could result in new and effective treatment strategies. Kinetic models of influenza viral growth and decay can summarize data and evaluate the biological parameters governing interactions between the virus and the host. Here we discuss recent viral kinetic models for influenza. We show how these models have been used to provide insight into influenza pathogenesis and treatment, and we highlight the challenges of viral kinetic analysis, including accurate model formulation, estimation of important parameters, and the collection of detailed data sets that measure multiple variables simultaneously. WIREs Syst Biol Med 2011 3 429–445 DOI: 10.1002/wsbm.129This article is categorized under:

Analytical and Computational Methods > Computational Methods