bluuebunny/crossref_metadata_2025_split huggingface dataset:
Porous metals in orthopedic applications – A review
Authors: Levine B.R. , Fabi D.W. 
Published: January 2011

AbstractThe development of porous metals and coatings for osseointegration has revolutionized the specialty of orthopedics, particularly total joint reconstruction. However, until recently most implants are fabricated utilizing traditional materials (i. e. sintered beads, fiber metal, plasma spray), which have several inherent limitations. Several new highly porous metals have been recently introduced to improve upon the biomaterial properties of traditional coatings, namely porosity, surface coefficient and modulus of elasticity. These new biomaterials have a similar microscopic appearance that is much like cancellous bone. The open‐cell structure of these metals affords several intriguing properties, including; high volumetric porosity (60–80%), low moduli of elasticity and high surface frictional characteristics. The self‐passivating nature of these metals and complex nanostructures allow for rapid bone ingrowth in multiple applications of orthopedic surgery. The following represents a review of contemporary implants and biomaterial properties in orthopedic surgery for this class of highly porous metals.Die Entwicklung poröser Metalle und Beschichtungen für die Osseointegration führte zu einer Revolution auf dem orthopädischen Spezialgebiet der totalen Gelenksrekonstruktion. Jedoch wurden bis vor kurzem die meisten Implantate nach traditionellen Methoden (gesinterte Kügelchen, Metallfasern oder Plasmasprayverfahren) hergestellt, die im Einsatz eine Reihe von inhärenten Nachteilen aufweisen. Einige neuen hochporösen Metalle wurden kürzlich eingeführt, die die Biomaterialeigenschaften traditioneller Schichten wie z. B. die Porosität, Oberflächenkoefficient und ‐modulus der Elastizität verbessern sollen. Diese neuen Materialien haben eine ähnliche mikroskopische Struktur wie spongiöser Knochen. Die offenzellige Struktur dieser Metalle bietet eine Reihe von faszinierenden Eigenschaften, wie z.B. eine hohe Volumenporosität (60–80%), niedrige Elastizitätsmoduli und hohe Reibungskennwerte. Die selbstpassivierende Natur dieser Materialien und komplexe Nanostrukturen erlauben ein schnelles Einwachsen von Knochen in vielen Anwendungen der orthopädischen Chirurgie. Die folgend Abhandlung gibt einen Überblick über die heutigen Implantate und Biomaterialeigenschaften der Klasse hochporöser Metalle in der orthopädischen Chirurgie.
Evaluation of degradable bone cements for percutaneous augmentation of bone defects
Authors: Müller‐Mai C. M. , Berger G. , Stiller M. , Gildenhaar R. , Jörn D. , Ploska U. , Houshmand A. , Bednarek A. , Koch C. , Knabe C. 
Published: January 2011

AbstractIn this study, two novel bioactive bone‐bonding cements based on the crystalline phase Ca2KNa(PO4)2 were studied in vivo in order to characterize their bone regenerative capacities as well as their biodegradability. The implantation site was located underneath the patellar sliding plane of the distal femur of rabbits in an area which is almost free of bony trabeculae. Highly porous β‐TCP granules and empty defects served as controls. In order to obtain information especially regarding the remodeling properties time periods of up to 48 weeks were chosen. When used as bulk material, both cements showed bone formation rates which were comparable to those of the TCP granules in combination with a favorable biodegradability, which however was lower than that of TCP granules due to the considerably lower porosity. Taken together, a guided bone regeneration in conjunction with biomaterials degradation was observed with all three materials. The empty defects (negative control) did not show comparable bone formation rates. Based on this study, both cements can be considered as valuable materials for percutaneous treatment of bone defects in traumatology, for example.Zwei neue bioaktive knochenbindende Zemente wurden in einem Tiermodel getestet. Die kristalline Hauptphase war Ca2KNa(PO4)2. Untersucht werden sollten die Knochenregeneration und Degradation. Die Materialien wurden hinter dem Patellagleitlager von Kaninchen implantiert. Hier besteht ein Areal, was physiologischer Weise arm an Knochentrabekeln ist. Als Kontrollen dienten ein TCP‐Granulat und Leerdefekte. Um Informationen besonders über den Remodelingprozess zu erhalten, wurden Zeitpunkte von bis zu 48 Wochen gewählt. Beide Zemente füllten die Defekte vollständig. Sie zeigten vergleichbare Raten der Knochenneubildung wie TCP‐Partikel, wobei die Degradation geringer bzw. langsamer als die der TCP Partikel war aufgrund der geringeren Porosität der Zemente. Die Degradation erreichte nach 48 Wochen jedoch fast den gesamten Defekt, so dass bei gleichzeitiger Knochenbildung von einer gerichteten Knochenregeneration im Defekt gesprochen werden kann. Leerdefekte blieben ohne wesentliche Knochenneubildung. Beide Zemente stellen daher geeignete Materialien zur perkutanen Auffüllung z.B. in der unfallchirurgischen operativen Praxis dar.
Planetary atmospheres
Authors: Taylor Fredric W. 
Published: January 2011

AbstractPlanetary meteorologists seek to understand the origin and evolution of the family of planets that orbit the Sun, to investigate the stability of their atmospheres and to compare the surface environment and climate with the Earth. The radiative, dynamical and chemical processes in Earth's atmosphere all have analogues on the other planets: by studying all of them, we learn more than by studying the Earth as an isolated example. Space missions to the planets are now sufficiently numerous and sophisticated, and computer models sufficiently versatile, to make such studies meaningful. This article reviews the current state of knowledge. Copyright © 2010 Royal Meteorological Society
Climate change and its human dimensions based on GIS and meteorological statistics in Pearl River Delta, Southern China
Authors: Dou Haoyang , Zhao Xinyi 
Published: January 2011

AbstractClimate change in the Pearl River Delta (PRD) has attracted growing attention along with rapid urbanization in Southern China. Annual mean temperatures in this area have increased more rapidly than the average level, which can be attributed to population expansion and land use changes in this region.In this study, temperature records from 31 weather stations in the PRD in Guangdong, China and the global dataset from the National Centres for Environmental Prediction (NCEP) Reanalysis (R‐2) are analysed. Data from NCEP R‐2 and temperature soundings taken at 850 hPa are used to define the background temperature. Anthropogenic temperature is then calculated according to the observed temperature and background temperature. The relationships of anthropogenic temperature to population density and area ratio of land‐use types are analysed by univariate and multiple regression analysis techniques.Spatial distribution of anthropogenic temperature in the daytime is different from that at night. Model results indicate that relationships between population and anthropogenic temperature in the daytime are logarithmic or inverse but tend to be linearly related at night. Multiple regression analysis conducted on the area ratios of land‐use types and anthropogenic temperature shows that a strong relationship exists between the two in spring and autumn. Positive correlations with anthropogenic temperature from arid land, water bodies and urban land, as well as a negative correlation from woodland, are detected regardless of time of day. Contrary to the paddy field, grassland and sea show a negative correlation with anthropogenic temperature in the daytime and a positive correlation at night. Copyright © 2010 Royal Meteorological Society
Wind speed variability over Iran and its impact on wind power potential: a case study for Esfehan Province
Authors: Rahimzadeh Fatemeh , Noorian Ali Mohammad , Pedram Mojdeh , Kruk Michael C. 
Published: January 2011

AbstractAccording to the Intergovernmental Panel on Climate Change (IPCC), there is a need to carry out in‐depth research into the potential for renewable energy as part of international efforts to combat climate change and reduce dependency on fossil fuels. The purpose of this study is to examine long‐term wind speed variability using seasonal and annual wind speed data at 32 Iranian synoptic stations from 1960 to 2005 to assess if wind power is a plausible source of renewable energy for Iran. Least‐square regression methods and the Kruskal–Wallis test were used to determine the trends and decadal changes in wind speed.Esfehan province was selected for assessment of the impacts on wind power potential owing to its progressive and forward thinking in exploration of renewable energy. Wind power potential was estimated by fitting a hybrid of the Weibull distribution to the 3 hourly wind data.This assessment revealed a declining trend in annual wind speeds in the central part of Iran and an increasing trend near the Iranian borders during the study period. The patterns on seasonal and annual scales were generally similar.The results indicated a similar pattern of wind power variation for stations in Esfehan province, except Ardestan. The monthly wind power potential from November to January and from February to May may be representative of the low and high periods of wind energy, respectively. Consequently, despite the existence of wind speed variability and general declining trends across Esfehan province, wind energy may be explored further over the coming years by employing modern wind turbines that require lower start‐up speeds. Copyright © 2010 Royal Meteorological Society
Cytogenetic analysis of 355 cases of fetal loss in different trimesters
Authors: Zhang Lin , Zhang Xiao‐hong , Wang Jian‐liu , Ren Mei‐hong , Pei Qiu‐yan , Wei Jun 
Published: January 2011

AbstractObjectiveWe estimated the success rates of cytogenetic analyses in different tissue samples after intrauterine fetal deaths and analyzed the value of cytogenetic testing for determining the causes.MethodsWomen with intrauterine fetal deaths (occurring at > 10 weeks of gestation) were offered either invasive testing before medical induction of labor, or solid tissue biopsy diagnosis after delivery.ResultsA total cohort of 355 intrauterine fetal deaths was studied. During antepartum examinations, invasive procedures included amniocentesis (AMC), chorionic villus sampling (CVS) and umbilical cord (UBC) sampling. During postpartum examinations, samples were taken from unfixed specimens of fetal skin, placenta and other tissues. Chromosomal abnormalities were observed in 22 fetal deaths for which cytogenetic analyses were successful. Logistic regression analysis identified antepartum invasive sampling [P = 0.000, odds ratio (OR) 31.125, 95% confidence interval (CI) 14.265–67.908] to be associated with a high cytogenetic success rate and older age with fetal deaths (P = 0.104, OR 0.487, 95% CI 0.204–1.160) not to be associated with a high chromosomal abnormality. In the patients with recurrent pregnancy loss, the chromosomal abnormality rate of 18.6% of spontaneous abortions has not been significantly more than that of fetal deaths 11.5% (P = 0.437).ConclusionParents should be counseled on all aspects of cytogenetic analysis after fetal death. Antepartum testing after pregnancy loss is recommended. Copyright © 2011 John Wiley & Sons, Ltd.
Aberrant lymphatic development in euploid fetuses with increased nuchal translucency including Noonan syndrome
Authors: de Mooij Yolanda M. , van den Akker Nynke M. S. , Bekker Mireille N. , Bartelings Margot M. , van Vugt John M. G. , Gittenberger‐de Groot Adriana C. 
Published: January 2011

AbstractObjectiveIncreased nuchal translucency in the human fetus is associated with aneuploidy, structural malformations and several syndromes such as Noonan syndrome. In 60–70% of the Noonan syndrome cases, a gene mutation can be demonstrated. Previous research showed that aneuploid fetuses with increased nuchal translucency (NT) demonstrate an aberrant lymphatic endothelial differentiation.MethodFetuses with increased NT and normal karyotype (n = 7) were compared with euploid controls having normal NT (n = 5). A Noonan syndrome gene mutation was found in three out of seven fetuses with increased NT. Endothelial differentiation was evaluated by immunohistochemistry using lymphatic markers (PROX‐1, Podoplanin, LYVE‐1) and blood vessel markers vascular endothelial growth factor‐A (VEGF‐A), Neuropilin‐1 (NP‐1), Sonic hedgehog, von Willebrand factor, and the smooth muscle cell marker, smooth muscle actin.ResultsNuchal edema and enlarged jugular lymphatic sacs (JLSs) were observed in fetuses with increased NT, together with abnormal lymphatic endothelial differentiation i.e. the presence of blood vessel characteristics, including high levels of VEGF‐A and NP‐1 expression. The enlarged JLSs contained erythrocytes and were surrounded by smooth muscle cells.ConclusionThis study shows an aberrant lymphatic endothelial differentiation in fetuses with increased NT and a normal karyotype (including Noonan syndrome fetuses), as was previously reported before in aneuploid fetuses. Copyright © 2011 John Wiley & Sons, Ltd.
Adjustment of maternal serum alpha‐fetoprotein levels in women with pregestational diabetes
Authors: Sprawka Nicole , Lambert‐Messerlian Geralyn , Palomaki Glenn E. , Eklund Elizabeth E. , Canick Jacob A. 
Published: January 2011

AbstractObjectiveDecreased second trimester levels of maternal serum alpha‐fetoprotein (MSAFP) have been reported in women with pregestational diabetes leading some laboratories to use a correction factor. The aim of this study is to determine if MSAFP levels in pregnant women with diabetes managed on oral antidiabetic agents is lower than non‐diabetic controls and require adjustment similar to those on insulin.Study designWe performed a nested case/control study of an existing dataset using women with pregestational diabetes who had routine MSAFP values available.ResultsBefore adjusting the MSAFP value for weight, both the diabetic patients who used insulin (n = 68) and those who used oral antidiabetic agents (n = 37) showed a non‐significant trend toward a lower multiples of the median (MoM) as compared with controls (n = 244). After converting the raw MSAFP values to race‐adjusted MoM and adjusting for weight, the median MSAFP MoM for women taking insulin (1.01) versus those on oral antidiabetic agents (1.00) were essentially the same. Furthermore, both of the diabetic groups were virtually identical to non‐diabetic controls.ConclusionsIn our study, women with pregestational diabetes managed on either insulin or oral antidiabetic agents had weight‐adjusted MSAFP MoM levels equivalent to those in control pregnancies and did not require a correction factor. Copyright © 2011 John Wiley & Sons, Ltd.
Maternal serum insulin‐like growth factor‐binding protein‐1 (IGFBP‐1) at 11–13 weeks in pre‐eclampsia
Authors: Sifakis Stavros , Akolekar Ranjit , Kappou Dimitra , Mantas Nikitas , Nicolaides Kypros H. 
Published: January 2011

AbstractObjectiveThe aim of this study was to determine the maternal serum concentration of insulin‐like growth factor‐binding protein‐1 (IGFBP‐1) at 11–13 weeks' gestation in pregnancies that subsequently develop pre‐eclampsia (PE) and to examine the possible association with uterine artery pulsatility index (PI).MethodsMaternal serum concentration of IGFBP‐1 and uterine artery PI were measured in 60 cases that developed PE, including 20 that required delivery before 34 weeks (early‐PE) and 120 unaffected controls. The measured IGFBP‐1 concentration and uterine artery PI were converted into a multiple of the expected median (MoM) in unaffected pregnancies and median MoM values were compared in the outcome groups. Regression analysis was used to determine the significance of association of IGFBP‐1 MoM with uterine artery PI MoM.ResultsIn the early‐ and late‐PE groups, the median IGFBP‐1 was decreased (0.63 and 0.67 MoM, respectively) and uterine artery PI was increased (1.31 and 1.19 MoM, respectively). In the group that developed PE there were no significant associations between serum IGFBP‐1 with uterine artery PI (p = 0.210).ConclusionIn pregnancies that develop PE, the serum IGFBP‐1 is decreased from the first trimester suggesting that IGFBP‐1 may be implicated in the pathogenesis of PE in a mechanism unrelated to impaired placental perfusion. Copyright © 2011 John Wiley & Sons, Ltd.
Hypomethylated DSCR4 is a placenta‐derived epigenetic marker for trisomy 21
Authors: Du Yingying , Zhang Jin , Wang Huijun , Yan Xiaoling , Yang Yingjun , Yang Lu , Luo Xin , Chen Yating , Duan Tao , Ma Duan 
Published: January 2011

AbstractBackgroundTrisomy 21 is the most common chromosomal aberration in live births. Some efforts have been made to develop noninvasive prenatal detection of trisomy 21 by using fetal DNA in maternal plasma. Due to the maternal DNA background, a distinguishable marker between maternal DNA and fetal DNA must be used, such as DNA methylation. The objective of this study was to search for fetal‐specific methylation markers on chromosome 21.MethodsWe chose six genes highly or specifically expressed in placenta and screened the methylation status of these gene promoter regions by combination of methylated‐DNA precipitation and methylation‐sensitive restriction enzymes assay (COMPARE‐MS). We further determined the methylation status of each CpG site within selected gene fragments by bisulfite sequencing. At last, we detected the placenta‐derived methylation marker in the first‐trimester maternal plasma by real‐time methylation‐specific PCR (MSP).ResultsDown syndrome (DS) critical region gene 4 (DSCR4) promoter region was found to be hypomethylated in placental tissues and densely methylated in maternal blood cells. Unmethylated DSCR4 (Down syndrome) sequence can be detected in the first‐trimester maternal plasma.ConclusionDSCR4 promoter DNA is a candidate fetal epigenetic marker for noninvasive prenatal detection of trisomy 21. Copyright © 2011 John Wiley & Sons, Ltd.
Computer simulation and preparation of molecularly imprinted polymer membranes with chlorogenic acid as template
Authors: Li Xiu Fang , Zhong Shi An , Chen Lan , Whittaker Andrew 
Published: January 2011

AbstractA computational approach was developed for screening functional monomers for rational design of molecularly imprinted polymer (MIP) membranes. It was based on a comparison of the binding energy of complexes between a template and various functional monomers. According to the results of theoretical calculations, MIP membranes with chlorogenic acid as a template were prepared with a UV irradiation polymerization method, using 4‐vinylpyridine as a functional monomer and N,N′‐methylenebisacrylamide as a crosslinker, with poly(vinylidene fluoride) microfiltration membranes as the support. Membranes covered with a thin layer of imprinted polymer selective to chlorogenic acid were then obtained and tested using the equilibrium‐adsorption method. The high affinity of these synthetic membranes to chlorogenic acid, together with their straightforward and inexpensive preparation, provides a good basis for the development of applications of imprinted polymers in separation processes such as solid‐phase extraction. Copyright © 2011 Society of Chemical Industry
Synthesis of spin labelled silica and EPR molecular dynamics study at silica–polymer interfaces
Authors: Dondi D. , Pepori F. , Buttafava A. , Ottaviani M.F. , Faucitano A. 
Published: January 2011

AbstractInformation concerning the interface structure in filler/polymer composites is of key importance for the rationalization of reaction mechanisms in mechano‐chemical (extrusion, blending, etc.), thermal or radiation induced free radical processes and for elucidating the factors underlying the reinforcing mechanism. The analysis of the chain dynamics is a suitable tool for undertaking such investigations because any reactivity parameter (rate constants, collisional frequencies, activation energies) and bonding interactions are strictly related to the mobility of the interacting centres. EPR spectroscopy coupled with specific spin labelling at the filler/polymer interface is a tool for making such novel perspective available. In this work, a spin labelling study of the molecular motion at the filler–rubber interface in a silica–SBR blend is reported. Spin labels of different length, spanning a 9–11 Å depth and linked to the surface of silica particles, were prepared and used for determining the rotational diffusion tensors, the T50 and order parameter in silica/SBR interfaces. The measurements carried out as a function of the temperature in comparison with unbound spin probes dispersed in the rubber matrix have afforded information consistent with the structure of the interfaces predicted by molecular–level theoretical models. Copyright © 2010 John Wiley & Sons, Ltd.
The N0‐binding region of the vesicular stomatitis virus phosphoprotein is globally disordered but contains transient α‐helices
Authors: Leyrat Cédric , Jensen Malene Ringkjøbing , Ribeiro Euripedes A. , Gérard Francine C. A. , Ruigrok Rob W. H. , Blackledge Martin , Jamin Marc 
Published: January 2011

AbstractThe phosphoprotein (P) of vesicular stomatitis virus (VSV) interacts with nascent nucleoprotein (N), forming the N0–P complex that is indispensable for the correct encapsidation of newly synthesized viral RNA genome. In this complex, the N‐terminal region (PNTR) of P prevents N from binding to cellular RNA and keeps it available for encapsidating viral RNA genomes. Here, using nuclear magnetic resonance (NMR) spectroscopy and small‐angle X‐ray scattering (SAXS), we show that an isolated peptide corresponding to the 60 first N‐terminal residues of VSV P (P60) and encompassing PNTR has overall molecular dimensions and a dynamic behavior characteristic of a disordered protein but transiently populates conformers containing α‐helices. The modeling of P60 as a conformational ensemble by the ensemble optimization method using SAXS data correctly reproduces the α‐helical content detected by NMR spectroscopy and suggests the coexistence of subensembles of different compactness. The populations and overall dimensions of these subensembles are affected by the addition of stabilizing (1M trimethylamine‐N‐oxide) or destabilizing (6M guanidinium chloride) cosolvents. Our results are interpreted in the context of a scenario whereby VSV PNTR constitutes a molecular recognition element undergoing a disorder‐to‐order transition upon binding to its partner when forming the N0–P complex.
Structural repertoire of immunoglobulin λ light chains
Authors: Chailyan Anna , Marcatili Paolo , Cirillo Davide , Tramontano Anna 
Published: January 2011

AbstractThe immunoglobulin λ isotype is present in nearly all vertebrates and plays an important role in the human immune system. Despite its importance, few systematic studies have been performed to analyze the structural conformation of its variable regions, contrary to what is the case for κ and heavy chains. We show here that an analysis of the structures of λ chains allows the definition of a discrete set of recurring conformations (canonical structures) of their hypervariable loops and, most importantly, the identification of sequence constraints that can be used to predict their structure. We also show that the structural repertoire of λ chains is different and more varied than that of the κ chains, consistently with the current view of the involvement of the two major light‐chain families in complementary strategies of the immune system to ensure a fine tuning between diversity and stability in antigen recognition. Proteins 2011; © 2011 Wiley‐Liss, Inc.