bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simplified seismic analysis of asymmetric building systems
Authors: Lin Jui‐Liang , Tsai Keh‐Chyuan 
Published: September 2006

AbstractThe paper reviews the uncoupled modal response history analysis (UMRHA) and modal pushover analysis (MPA) procedure in the analysis of asymmetric structures. From the pushover curves in ADRS format, showing the relationships of base shear versus roof translation and base torque versus roof rotation, a bifurcating characteristic of the pushover curves of an asymmetric structure is observed. A two‐degree‐of‐freedom (2DOF) modal stick is constructed using lump mass eccentrically placed at the end of beam which is connected with the column by a rotational spring. By converting the equation of motion of a whole structure into 2DOF modal equations, all of the elastic properties in the 2DOF modal sticks can be determined accurately. A mathematical proof is carried out to demonstrate that the 2DOF modal stick is consistent with the single‐degree‐of‐freedom (SDOF) modal stick at elastic state. The bifurcating characteristic of modal pushover curves and the interaction of modal translation and rotation can be considered rationally by this 2DOF modal stick. In order to verify the effectiveness of this proposed 2DOF modal stick, a two‐storey asymmetric building structure was analysed by the UMRHA procedure incorporating this novel 2DOF modal sticks (2DMPA) and conventional SDOF modal sticks (SDMPA), respectively. The analytical results are compared with those obtained by nonlinear response history analysis (RHA). It is illustrated that the accuracy of the rotational response histories obtained by 2DMPA is much better than those obtained by SDMPA. Consequently, the estimations of translational response histories on flexible side (FS) and stiff side (SS) of the building structure are also improved. Copyright © 2006 John Wiley & Sons, Ltd.
Non‐avian dinosaur fossils from the Lower Cretaceous Jehol Group of western Liaoning, China
Authors: Xing Xu , Norell Mark A. 
Published: September 2006

AbstractOver the past 10 years, numerous dinosaur specimens covering several major dinosaurian clades have been recovered from the Lower Cretaceous Jehol Group of western Liaoning. Among ornithischians from the Jehol Group, ornithopod fossils shed new light on the evolution of this largest ornithischian group; ankylosaurian discoveries add morphological diversity relevant to the highly specialized ankylosaurian body‐plan and ceratopsian occurrences offer a chance to study patterns of morphological change at the base of the Ceratopsia. The most significant discoveries are exceptionally well‐preserved theropod specimens covering most major coelurosaurian groups. Most theropod taxa from the Jehol Biota are the earliest, most basal members of coelurosaurian sub‐clades and provide substantial new information important for the reconstruction of coelurosaurian phylogeny and understanding the character evolution. The examination of character distributions along the coelurosaurian lineages reveals that the major structural modifications seen in birds were acquired sequentially and hierarchically early in coelurosaurian evolution. Most significantly, the Liaoning theropod discoveries advanced our understanding of two long‐debated evolutionary issues: the origin and early evolution of feathers and the origin of avian flight. The known distribution of the feather‐like integumentary structures and true feathers along the coelurosaurian lineages suggests that: (1) simple, filamentous integuments represent a primitive morph in feather evolution; (2) pennaceous feathers evolved early in maniraptoran evolution; and (3) feathers with aerodynamic features originated before the origin of birds. The presence of flight feathers on the metatarsus represents a new morph that is not known previously, but it has implications for understanding the origin of avian flight. The discovery of four‐winged dinosaurs was suggested to provide strong evidence supporting the ‘tree‐down’ hypothesis for the origin of avian flight, though in‐depth analysis and more data are needed to confirm this. A brief analysis of the fossil preservation and faunal composition reveals several interesting characteristics: (1) Volcanic activity might have contributed to the exceptional preservation of dinosaurian skeletons and in particular their soft tissues; (2) Different from most other dinosaur faunas, the Jehol dinosaur fauna has a low ornithischian specific diversity relative to a high theropod specific diversity; and (3) the Liaoning theropods show a strong tendency toward secondary herbivory. The faunal composition suggests a complex biogeographic history for this fauna and provides negative evidence for the hypothesis that eastern Asia was isolated from the Middle Jurassic through late Early Cretaceous times. Copyright © 2006 John Wiley & Sons, Ltd.
The mammal fauna in the Early Cretaceous Jehol Biota: implications for diversity and biology of Mesozoic mammals
Authors: Jin Meng , Yaoming Hu , Chuankui Li , Yuanqing Wang 
Published: September 2006

AbstractEleven species belonging to five major groups of mammals (multituberculates, eutriconodontans, ‘symmetrodontans’, metatherians and eutherians) have been described from the Jehol Biota, Liaoning, China. These fossils came from three horizons of the Yixian Formation: Lujiatun (lowest), Jianshangou and Dawahgzhangzi (highest) beds. Ages and correlations of these beds are still in debate, but are generally accepted as Early Cretaceous. Biostratigraphic distributions of some Jehol mammals corroborate the Early Cretaceous age of the biota. Many species are represented by skulls and articulated skeletons, although in most cases a species is known only from a single holotype that is squashed. These fossils furnish a wealth of morphological data for Mesozoic mammals, from which large character data sets have been amassed to generate competing higher‐level phylogenetic hypotheses of mammals. The Early Cretaceous divergence of eutherians is first documented as skull and skeletal fossils. The Jehol mammals indicate a diverse mammal fauna in which species range from 25 g to 14 000 g in body masses, have insectivorous, omnivorous and carnivorous diets (as reflected by their dentitions and by stomach content), and acquire scansorial, possibly arboreal and terrestrial habits (as inferred from articulated skeletons). The well‐preserved material helps to clarify some anatomical uncertainties in the study of early mammals, such as an ossified Meckel's cartilage as the occupant for the internal groove on the lower jaw of some Mesozoic species and a dental formula I3‐C1‐P3‐M4/i2‐c1‐p2‐3‐m5 for gobiconodontids as suggested by dentitions of several Jehol eutriconodontans. Evidence from cranial specimens of Jehol eutriconodontans also disfavours the brain‐expansion model for the detachment of middle ear ossicles from the dentary during evolution of mammals. Copyright © 2006 John Wiley & Sons, Ltd.
Metallurgical characterization, galvanic corrosion, and ionic release of orthodontic brackets coupled with Ni‐Ti archwires
Authors: Darabara Myrsini S. , Bourithis Lefteris I. , Zinelis Spiros , Papadimitriou George D. 
Published: September 2006

AbstractIn orthodontics, a combination of metallic alloys is placed into the oral cavity during medical treatment and thus the corrosion resistance and ionic release of these appliances is of vital importance. The aim of this study is to investigate the elemental composition, microstructure, hardness, corrosion properties, and ionic release of commercially available orthodontic brackets and Copper Ni‐Ti archwires. Following the assessment of the elemental composition of the orthodontic wire (Copper Ni‐Ti™) and the six different brackets (Micro Loc, Equilibrium, OptiMESHXRT, Gemini, Orthos2, and Rematitan), cyclic polarization curves were obtained for each material to estimate the susceptibility of each alloy to pitting corrosion in 1M lactic acid. Galvanic corrosion between the orthodontic wire and each bracket took place in 1M lactic acid for 28 days at 37°C and then the ionic concentration of Nickel and Chromium was studied. The orthodontic wire is made up from a Ni‐Ti alloy with copper additions, while the orthodontic brackets are manufactured by different stainless steel grades or titanium alloys. All tested wires and brackets with the exception of Gemini are not susceptible to pitting corrosion. In galvanic corrosion, following exposure for 28 days, the lowest potential difference (∼250 mV) appears for the orthodontic wire Copper Ni‐Ti and the bracket made up from pure titanium (Rematitan) or from the stainless steel AISI 316 grade (Micro Loc). Following completion of the galvanic corrosion experiments, measurable quantities of chromium and nickel ions were found in the residual lactic acid solution. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Biocompatibility of resin‐based dental materials applied as liners in deep cavities prepared in human teeth
Authors: de Souza Costa Carlos Alberto , Teixeira Hilcia Mezzalira , Nascimento Alexandre Batista Lopes do , Hebling Josimeri 
Published: September 2006

AbstractBackground: Since only a few data have been published concerning the effects of resinous dental materials on the pulp–dentin complex, the aim of this study was to evaluate the biocompatibility of resin‐based materials applied as liners in deep cavities prepared in human teeth. Methods: After preparing class V cavities, the following dental materials were applied on the axial walls: group 1, Vitrebond™ (VIT; 3M ESPE); group 2, Ultra‐Blend® Plus™ (UBP; Untradent); and group 3, Clearfil™ SE Bond (CSEB; Kuraray). In group 4 (control), the hard‐setting calcium hydroxide cement Dycal (CH; Caulk/Dentsply) was used. The teeth extracted at 7 days or between 30 and 85 days after the clinical procedures were processed for histological evaluation. Results: For all the experimental and control groups, most of specimens exhibited no pulpal response or slight inflammatory reaction associated with slight tissue disorganization at 7‐day period. Moderate inflammatory pulpal response occurred only in one tooth (RDT = 262 μm) of group 3 in which transdentinal diffusion of resin components was observed. Conclusion: The resin‐based dental cements VIT and UBP as well as the bonding agent CSEB presented acceptable biocompatibility when applied in deep cavities prepared in sound human teeth. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Influence of contamination on bonding to zirconia ceramic
Authors: Yang Bin , Scharnberg Michael , Wolfart Stefan , Quaas Anne C. , Ludwig Klaus , Adelung Rainer , Kern Matthias 
Published: September 2006

AbstractThe purpose of this study was to investigate the influences of contaminations and cleaning methods on bonding to dental zirconia ceramic. After saliva immersion and using silicone disclosing agent, airborne‐particle abraded ceramic specimens were cleaned with isopropanol (AL), acetone (AC), 37% phosphoric acid (PA), additional airborne‐particle abrasion (AA), or only with water rinsing (SS). Airborne‐particle abraded specimens without contaminations (CL) were used as control group. For chemical analysis specimens of all groups were examined with X‐ray photoelectron spectroscopy (XPS). Plexiglas tubes filled with composite resin were bonded to ceramic specimens using a phosphate‐monomer containing composite luting resin. After 3‐day water storage, tensile bond strengths (TBS) were tested. XPS analysis of group SS showed the presence of saliva and silicone (Si) contamination on the surface. The ratios of carbon/zirconium and oxygen/zirconium for groups PA and AA were comparable to those ratios obtained for group CL, indicating the removal of the organic saliva contamination. Airborne‐particle abrasion and acetone completely removed Si contamination from ceramic surfaces. Isopropanol had little cleaning effect on the two contaminants. TBS (median ± standard deviation) in MPa of the groups SS (11.6 ± 3.1), AL (10.0 ± 2.9), and AC (13.0 ± 2.8) were statistically lower than those of groups PA (33.6 ± 5.5), AA (40.1 ± 3.6), and CL (47.0 ± 8.1) (p < 0.001), while no differences were found in TBS between groups AA and CL (p > 0.5). Contamination significantly reduced bond strengths to zirconia ceramic. Airborne‐particle abrasion was the most effective cleaning method. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
A biodegradable copolymer for the slow release of growth hormone expedites scarring in diabetic rats
Authors: García‐Esteo Francisco , Pascual Gemma , Gallardo Alberto , San‐Román Julio , Buján Julia , Bellón Juan Manuel 
Published: September 2006

AbstractIn many diseases wound healing is impaired. This study was designed to establish whether the healing process in diabetes could be improved using a site‐specific polymer delivery system containing hGH. The system was first optimized in in vitro experiments performed on cultured fibroblasts taken from healthy and diabetic rats and then tested in an incisional wound model created in the diabetic Wistar rat. In the in vitro experiments using cultured fibroblasts, cell viability, growth, and proliferation were determined, along with polymer degradation, hormone release rates and the expression of TGFβ1 in the culture medium. For the in vivo experiments, polymer discs with/without GH were inserted through 3 cm incisions made on the backs of the animals. Wound specimens were obtained 7 and 30 days after surgery to evaluate inflammatory/apoptotic cells, metalloprotease expression and neoangiogenesis using microscopy and immunohistochemical techniques. The local administration of GH using a polymer delivery system did not affect the normal wound healing process. Conversely, when used in diabetic animals, epidermal and dermal repair was expedited. Our findings indicate that GH induces cell proliferation, enhances CD4+ infiltration; increases extracellular matrix protein deposition; stimulates angiogenesis; and diminishes apoptosis at the diabetic wound site. These effects give rise to a comparable wound healing process to that observed in healthy animals. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Deep rolling of titanium rods for application in modular total hip arthroplasty
Authors: Schuh Alexander , Zeller Christian , Holzwarth Ulrich , Kachler Werner , Wilcke Gerhard , Zeiler Günther , Eigenmann Bernd , Bigoney Jean 
Published: September 2006

AbstractCompressive residual stresses are commonly introduced into the near‐surface regions of morse taper junctions of modular hip endoprostheses to prolong fatigue life. An increasing number of publications report that contamination of shot‐peened surfaces can lead to enhanced corrosion and third body wear. This study evaluates deep rolling of titanium alloy rods as a possible alternative to shot peening. Ten rods of Ti6Al7Nb alloy with a diameter of 15 mm were deep rolled with various rolling parameters. The resulting surface topography and residual contamination was analyzed using a scanning electron microscope (SEM). The near‐surface residual stress states after deep rolling were characterized by means of X‐ray diffraction. The roughness of the surfaces before deep rolling was about Rz = 14 μm, and after deep rolling surface roughness values of Rz 0.4–7.5 μm were achieved. The results of the SEM and EDAX analyses of the sample surface showed no evidence of surface contamination by particles or abrasion products caused by any process. At a pressure of 300 bar, compressive stress reached the maximum of −1150 MPa at a depth of 0.1 mm. Deep rolling thus allows a smooth and particle‐free surface to be obtained and therefore shows promise as a surface treatment for mating surfaces of morse tapers in modular hip endoprostheses. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
An fMRI study of somatosensory‐implicated acupuncture points in stable somatosensory stroke patients
Authors: Li Geng , Jack Clifford R. , Yang Edward S. 
Published: September 2006

AbstractPurposeTo assess differences in brain responses between stroke patients and controls to tactile and electrical acupuncture stimulation using functional MRI (fMRI).Materials and MethodsA total of 12 male, clinically stable stroke patients with left side somatosensory deficits, and 12 age‐matched male control subjects were studied. fMRI was performed with two different paradigms; namely, tactile stimuli and electrical stimulation at acupuncture points LI4 and LI11 on the affected side of the body. fMRI data were analyzed using SPM99.ResultsTactile stimulation in both patients and controls produced significant activation in primary and secondary sensory and motor cortical areas and cerebellum. Greater activation was present in patients than controls in the somatosensory cortex with both the tactile task and the acupuncture point (acupoint) stimulation. Activation was greater during the tactile task than the acupuncture stimulation in patients and normal controls.ConclusionDifferences observed between patients and controls on both tasks may indicate compensatory over recruitment of neocortical areas involved in somatosensory perception in the stroke patients. The observed differences between patients and controls on the acupoint stimulation task may also indicate that stimulation of acupoints used therapeutically to enhance recovery from stroke, selectively activates areas thought to be involved in mediating recovery from stroke via functional plasticity. fMRI of acupoint stimulation may illustrate the functional substrate of the therapeutically beneficial effect of acupuncture in stroke rehabilitation. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Delayed hyperenhancement patterns in occlusive and reperfused myocardial infarcts during different healing stages
Authors: Wang Yi , Sun Wei , Cao Guang , Meng Liang , Song Laifeng , Du Xiangke 
Published: September 2006

AbstractPurposeTo investigate delayed hyperenhancement during different healing stages of myocardial infarct with and without reperfusion in a pig model.Materials and MethodsTwelve pigs were studied. Six pigs were subjected to permanent right coronary artery (RCA) occlusion, and the other six were subjected to transient 90‐minute RCA occlusion. In vivo MRI including first‐pass perfusion and myocardial delayed enhancement (MDE) was performed at four, eight, 12, and 24 hours, and eight days after the artery occlusion. The MDE scan was repeated four times, two to 32 minutes after contrast administration.ResultsFor all six pigs without reperfusion, the four‐hour MRI showed transmural perfusion defect and no delayed hyperenhancement; from eight hours on, delayed hyperenhancement appeared and its spatial extent gradually increased until it became transmural hyperenhancement at eight days. However, in all six pigs with reperfusion, hyperenhancement was present at every stage from four hours to eight days. Pathology confirmed the existence of infarct at various stages of healing irrespective of reperfusion status.ConclusionOcclusive hyperacute infarct did not exhibit any delayed hyperenhancement, which indicates that perfusion plays an important role in delayed enhancement at the hyperacute stage. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Spontaneous detorsion of the ovary: Can it be diagnosed by MRI?
Authors: Ghossain Michel A. , Hachem Kamal , Aoun Noël J. , Haddad‐Zebouni Soha , Mansour Fersan , Suidan Joseph S. , Abboud Joseph 
Published: September 2006

AbstractPurposeTo determine whether recent progress in imaging has made it possible to diagnose spontaneous detorsion, which is an accepted concept in the gynecological literature but until now has been a presumptive diagnosis that could not be confirmed because of the lack of imaging proof.Materials and MethodsWe searched for patients who had a diagnosis of spontaneous detorsion on MRI between January 2000 and January 2003, and selected only patients who met a selection of strict criteria, including mainly enlargement and hyperintensity of ovarian stroma on T2‐weighted (T2W) images, clinical findings compatible with torsion and detorsion, and return of the stroma to normal size on follow‐up examinations. Other signs of torsion, such as tubal thickening, were appreciated but not mandatory. Clinical follow‐up for at least three years was available.ResultsFour patients met the study criteria. No stabilizing procedure was performed in the ovaries. One patient recurred and lost her ovary.ConclusionThe diagnosis of torsion followed by spontaneous detorsion was made with high probability in a selected number of patients. The clinical management of such patients remains a matter of debate. Laparoscopy with oophoropexy would be useful for young patients in whom close follow‐up cannot be achieved. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Automated perfusion‐weighted MRI using localized arterial input functions
Authors: Lorenz Cory , Benner Thomas , Chen Poe Jou , Lopez Chloe Joan , Ay Hakan , Zhu Ming Wang , Menezes Nina M. , Aronen Hannu , Karonen Jari , Liu Yawu , Nuutinen Juho , Sorensen A. Gregory 
Published: September 2006

AbstractPurposeTo investigate the utility of an automated perfusion‐weighted MRI (PWI) method for estimating cerebral blood flow (CBF) based on localized arterial input functions (AIFs) as compared to the standard method of manual global AIF selection, which is prone to deconvolution errors due to the effects of delay and dispersion of the contrast bolus.Materials and MethodsAnalysis was performed on spin‐ and gradient‐echo EPI images from 36 stroke patients. A local AIF algorithm created an AIF for every voxel in the brain by searching out voxels with the lowest delay and dispersion, and then interpolating and spatially smoothing them for continuity. A generalized linear model (GLM) for predicting tissue outcome, and MTT lesion volumes were used to quantify the performance of the localized AIF method in comparison with global methods using ipsilateral and contralateral AIFs.ResultsThe algorithm found local AIFs in each case without error and generated a higher area under the receiver operating characteristic (ROC) curve compared to both global‐AIF methods. Similarly, the local MTT lesion volumes had the least mean squared error (MSE).ConclusionAutomated CBF calculation using local AIFs is feasible and appears to produce more useful CBF maps. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Separation and quantitation of fructose‐6‐phosphate and fructose‐1,6‐diphosphate by LC‐ESI‐MS for the evaluation of fructose‐1,6‐biphosphatase activity
Authors: Mancini Francesca , Fiori Jessica , Cavrini Vanni , Andrisano Vincenza 
Published: September 2006

AbstractAn LC‐ESI‐MS method was developed for the identification and quantification of fructose‐1,6‐biphosphate (F1,6BP) and fructose‐6‐phosphate (F6P), respectively the substrate and the product of the enzymatic reaction catalysed by fructose‐1,6‐bisphosphatase (F1,6BPase). F1,6BPase, expressed predominantly in liver and kidney, is one of the rate‐limiting enzymes of hepatic gluconeogenesis and has become a target for the development of new drugs for type 2 diabetes. The two sugar phosphates were separated on a Phenomenex Luna NH2 column (150 mm×2.0 mm id) using the following mobile phase: 5 mM triethylamine acetate buffer/ACN (80 : 20) v/v in a linear pH gradient (from pH = 9 to 10 in 15 min) at the flow rate of 0.3 mL/min. The detection was performed with an IT mass spectrometer in negative polarity (full scan 100–450 m/z) and in SIM mode on the generated anions at m/z = 339 (F1,6BP) and m/z = 259 (F6P). Under the optimised final conditions, the method was validated for accuracy, specificity, precision (inter‐ and intradays RSD comprised between 1.0 and 6.3% over the range of concentrations used), linearity (50–400 μM), LODs (0.44 μM) and LOQs (1.47 μM), and the method was applied to F6P determination in the F1,6BPase catalysed hydrolysis of F1,6BP.