bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human hypertrophic nonunion tissue contains mesenchymal progenitor cells with multilineage capacity in vitro
Authors: Iwakura Takashi , Miwa Masahiko , Sakai Yoshitada , Niikura Takahiro , Lee Sang Yang , Oe Keisuke , Hasegawa Takumi , Kuroda Ryosuke , Fujioka Hiroyuki , Doita Minoru , Kurosaka Masahiro 
Published: August 2008

AbstractHypertrophic nonunion usually results from insufficient fracture stabilization. Therefore, most hypertrophic nonunions simply require the stabilization of the nonunion site. However, the reasons why union occurs without treating the nonunion site directly is not well understood biologically. In this study, we hypothesized that the intervening tissue at the hypertrophic nonunion site (nonunion tissue) could serve as a reservoir of mesenchymal progenitor cells and investigated whether the cells derived from nonunion tissue had the capacity for multilineage mesenchymal differentiation. After nonunion tissue was obtained, it was cut into strips and cultured. Homogenous fibroblastic adherent cells were obtained. Flow cytometry revealed that the adherent cells were consistently positive for mesenchymal stem cell related markers CD13, CD29, CD44, CD90, CD105, CD166, and negative for the hematopoietic markers CD14, CD34, CD45, and CD133, similar to control bone marrow stromal cells. In the presence of lineage‐specific induction factors, the adherent cells differentiated in vitro into osteogenic, chondrogenic, and adipogenic cells. These results demonstrated for the first time that hypertrophic nonunion tissue contains multilineage mesenchymal progenitor cells. This suggests that hypertrophic nonunion tissue plays an important role during the healing process of hypertrophic nonunion by serving as a reservoir of mesenchymal cells that are capable of transforming into cartilage and bone forming cells. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:208–215, 2009
Changes of femoral periprosthetic bone mineral density 6 years after treatment with alendronate following total hip arthroplasty
Authors: Arabmotlagh Mohammad , Pilz Mathias , Warzecha Jörg , Rauschmann Michael 
Published: August 2008

AbstractEarlier osteodensitometric results of femoral periprosthetic bone showed that postoperative antiresorptive treatment with alendronate following total hip arthroplasty (THA) reduces the periprosthetic bone loss that commonly occurs in the first months after surgery. However, whether alendronate can prevent periprosthetic bone loss over the long term, or if bone loss occurs after discontinuing alendronate is unknown. Femoral periprosthetic bone mineral density (BMD) was assessed in 49 patients 6 years after cementless total hip arthroplasty using dual energy X‐ray absorptiometry. Twenty‐nine patients were treated postoperatively with alendronate and 20 control patients received no treatment. All patients were followed up at 12 months after surgery in a prospective randomized study. The bone mineral density was evaluated in 7 regions of interest according to the Gruen protocol. Six years after total hip arthroplasty, no significant changes were detected in femoral periprosthetic BMD when compared with results at 1 year, and the bone loss in patients with postoperative alendronate treatment was still significantly less than those without treatment. These results suggest that the prevention of femoral periprosthetic bone loss following THA achieved by postoperative antiresorptive treatment with alendronate is of long‐standing effect, and further bone loss does not occur after the first postoperative year. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:183–188, 2009
Kunststoffe mit dem Laser beschriften
Authors: Faißt Birgit 
Published: August 2008

AbstractDer Laser als Markierwerkzeug ist aus der Industrie nicht mehr wegzudenken. Automobil, Elektronik sowie Medizintechnik sind nur einige wenige Industriezweige, in denen der Laser aufgrund seiner Flexibilität und Vielseitigkeit anderen Verfahren zum Beschriften vorgezogen wird. Die Nachfrage nach Markierlasern steigt, die Gründe dafür sind vielfältig.
Selektives Lasersintern
Authors: Exner Horst , Ebert Robby 
Published: August 2008

Abstract Das Selektive Lasersintern (SLS) hat sich seit nunmehr 20 Jahren zu einem industriell etablierten Verfahren entwickelt. Mit ihm lassen sich schnell und präzise Bauteile aus verschiedensten Materialien generieren. Kunststoff und Metall werden bereits in großer Vielfalt verarbeitet – die Verarbeitung von Keramik steht noch in den Startlöchern.
Measuring tissue heat penetration by scattered light measurements
Authors: Ben‐David M. , Cantor R. , Balbul N. , Yehuda M. , Gannot I. 
Published: August 2008

AbstractBackground and ObjectivesThe monitoring of tissue morphological changes during clinical procedure such as laser thermotherapy, laser hair removal and others is important in order to prevent damage to healthy tissue. An optical system and method for the assessment of real time in vivo tissue morphological changes is proposed.Materials and MethodsWe used ex vivo chicken breast as tissue samples. The samples were irradiated by CO2 laser to create thermal structural changes. The optical properties of the tissue samples were measured using an integrating sphere method. We measured the tissue heat penetration and the scattered light from the tissue and compared the results to Monte‐Carlo simulation.ResultsThermal interaction causes structural changes in the tissue. Therefore changing (increasing) the scattering properties of the tissue. We relate the structural changes to the scattered light pattern and proposed a method for controlling the thermal interaction.ConclusionIt is possible to design a real time in vivo controlling system for laser tissue thermal interaction that utilizes the changes in the scattered light pattern. Lesers Surg. Med. 40:494–499, 2008. © 2008 Wiley‐Liss, Inc.
Topical delivery of methotrexate via skin pretreated with physical enhancement techniques: low‐fluence erbium:YAG laser and electroporation
Authors: Lee Woan‐Ruoh , Shen Shin‐Chuan , Fang Chia‐Lang , Zhuo Rou‐Zi , Fang Jia‐You 
Published: August 2008

AbstractBackground and ObjectiveThe high hydrophilicity and molecular weight of methotrexate (MTX) make it difficult to deliver via the skin route for treating psoriasis or rheumatoid arthritis. The objective of this study was to enhance and optimize the skin permeation of MTX using two physical techniques: an erbium:yttrium‐aluminum‐garnet (Er:YAG) laser and electroporation.MethodsIn vitro skin permeation was performed using horizontal side‐by‐side diffusion cells. The animal model utilized nude mice. The skin where epidermal hyperproliferation was reproduced by repeated barrier abrogation was also used as a permeation barrier for MTX delivery.ResultsApplication of the laser and electroporation significantly enhanced the permeation of MTX. The enhancing effect was more pronounced after applying the laser. Er:YAG laser pretreatment on the skin produced a 3‐ to 80‐fold enhancement dependent upon the magnitude of the laser fluence. Using electroporation, treatment with 10 pulses resulted in a twofold increase in MTX flux. A combination of laser pretreatment and subsequent electroporation for 10 minutes resulted in a higher drug permeation than either technique alone. However, this synergistic effect was only observed when the lower laser fluence (1.4 J/cm2) was applied. Hyperproliferative skin generally showed a greater variability of MTX flux and lower permeation.ConclusionThe results shown in the present study encourage further investigation of laser‐ and electroporation‐assisted topical drug delivery. Lesers Surg. Med. 40:468–476, 2008. © 2008 Wiley‐Liss, Inc.
Effects of laser repetition rate on corneal tissue ablation for 193‐nm excimer laser light
Authors: Shanyfelt Leia M. , Dickrell Pamela L. , Edelhauser Henry F. , Hahn David W. 
Published: August 2008

AbstractBackground and ObjectiveThe goal of the present work is to assess whether bovine corneal ablations generated at laser repetition rates of up to 400 Hz are comparable to ablations performed at rates consistent with current clinical laser systems.Study Design/Materials and MethodsA combination of experiments was used to assess a comprehensive range of ablation parameters, including ablation plume dynamics via imaging and transmission, corneal ablation profiles via scanning interferometry, and high‐resolution electron microscopy of collagen structure following ablation.ResultsUsing white‐light interferometry analysis, no statistical difference was found between corneal ablation profiles created at 60 and 400 Hz, with an average rate of 0.94 µm/pulse at 60 Hz versus 0.92 µm/pulse at 400 Hz. In addition, based on plume imaging and transmission studies, the bulk ablation plume was found to dissipate on a time‐scale less than the pulse‐to‐pulse separation for a laser repetition rate up to about 400 Hz. A persistent, diffuse gas‐phase component of the ablation products was observed and concluded to be comparable at both repetition rates. Finally, SEM and TEM analysis revealed no signs of differential thermal tissue damage, including collagen fibril analysis, for laser repetition rates up to 400 Hz.ConclusionsIn summary, investigation of the relative effects of excimer laser repetition rate on the overall corneal ablation metrics revealed no measurable difference under conditions typical of clinical refractive procedures. This study suggests that increases in ArF laser repetition rates for clinical applications (up to ∼400 Hz) appear feasible. Lesers Surg. Med. 40:483–493, 2008. © 2008 Wiley‐Liss, Inc.
Low density, non‐ablative fractional CO2laser rejuvenation
Authors: Christiansen Kaare , Bjerring Peter 
Published: August 2008

AbstractBackground and ObjectivesFractional skin rejuvenation has gained increased interest since its introduction in 2003. Both non‐ablative and ablative lasers as well as different treatment techniques have been devised. Recent clinical studies indicate that a paradigm of low spot density combined with high fluences tend to produce better clinical results and less risk of post‐inflammatory hyperpigmentation in darker skin types. The present study is focused on investigations of the clinical outcome by non‐ablative fractional CO2treatments with a single pass with low spot density.Methods and MaterialsA CO2laser was equipped with a scanner enabling it to perform fractional treatments with 36, 64 or 100 microthermal zones (MTZ)/cm2. Twelve patients participated in the study. The perioral area was treated three times with 1‐month intervals using a spot density of 64 MTZ/cm2, a spot diameter of 0.5 mm, a micro‐beam energy of 36–60 mJ, and a pulse duration of 3–5 milliseconds. Follow‐up was performed 3 months after the last treatment.ResultsAt the 3‐month follow‐up 72.7% of the volunteers had obtained improvement in ultrasonographically determined dermal density, and the average improvement was 40.2% (SD: 48.0%). This improvement was statistically significant (P<0.006). Eighty percent of the volunteers rated the reduction in visible perioral wrinkles to be fair, good or excellent. For reduction of irregular pigmentation, fair, good or excellent clearance was reported by 62.5% of the volunteers.ConclusionsThe present study demonstrates subjective improvements in wrinkles, skin texture and mottled pigmentation as well as statistically significant objectively measured improvements in ultrasonographical dermal density after three non‐ablative fractional CO2laser treatments. Lesers Surg. Med. 40:454–460, 2008. © 2008 Wiley‐Liss, Inc.
A possible mechanism for visible light‐induced wound healing
Authors: Lipovsky Anat , Nitzan Yeshayahu , Lubart Rachel 
Published: August 2008

AbstractBackground and ObjectivesChronic wounds resistant to conventional therapy have been treated successfully with low energy lasers and light emitting diodes (LEDs) in the visible and near IR region. It has been proposed that production of low level reactive oxygen species (ROS) following illumination is the first step of photobiomodulation. It was also shown that white light (400–800 nm) has similar stimulatory effects as lasers and LEDs. ROS at higher levels are toxic to cells and bacteria.Study Design/Materials and MethodsIn the present study, we examined the phototoxicity of broadband (400–800 nm, 120 J/cm2) visible light on the survival of several pathogenic bacteria:Staphylococcus aureus 195,Pseudomonas aeruginosa 1316,Escherichia coli 1313, andSerratia marcescens. These bacteria were chosen due to their high prevalence in infected wounds. The survival of bacterial cells following illumination was monitored by counting the number of colony forming units before and after exposure to light.ResultsIllumination with white light, 120 J/cm2, caused a reduction of 62%, 83%, and 56% in the colony count ofE. coli 1313,S. aureus 195andS. marcescens, respectively, though no reduction in the viability ofP. aeruginosa 1316was demonstrated. The phototoxic effect was found to involve induction of ROS production by the bacteria. It was also found that illumination ofS. aureus 195andE. coli 1313in the presence of pyocyanin, known to be secreted byP. aeruginosa, had a stronger bactericidal effect compared to illumination alone.ConclusionVisible light at high intensity can kill bacteria in infected wounds. Thus, illumination of infected wounds with intense visible light, prior to low intensity illumination for stimulating wound closure, may reduce infection and promote healing. Lesers Surg. Med. 40:509–514, 2008. © 2008 Wiley‐Liss, Inc.
Fluoroelastomer Copolymers Incorporating Polyhedral Oligomeric Silsesquioxane
Authors: Seurer Bradley , Coughlin Edward Bryan 
Published: August 2008

AbstractThe aggregation of polyhedral oligomeric silsesquioxane (POSS) in copolymers was studied by incorporation of POSS into fluorinated copolymers, namely poly(octafluoropentyl acrylate) elastomers. The aggregation of POSS in copolymers affords unique materials. Studies of these novel polymers show POSS aggregates in these copolymers with both the phenyl and isobutyl peripheries, as the chain‐repulsive fluorinated chains help drive this aggregation. The isooctylPOSS copolymers, however, do not have POSS aggregation. Thermal studies of these copolymers also show an increase in the decomposition temperature by incorporation of POSS, which is directly dependent on the POSS periphery.magnified image
Uniformly computable aspects of inner functions: estimation and factorization
Authors: McNicholl Timothy H. 
Published: August 2008

AbstractThe theory of inner functions plays an important role in the study of bounded analytic functions. Inner functions are also useful in applied mathematics. Two foundational results in this theory are Frostman's Theorem and the Factorization Theorem. We prove a uniformly computable version of Frostman's Theorem. We then show that the Factorization Theorem is not uniformly computably true. We then show that for an inner function u with infinitely many zeros, the Blaschke sum of u provides the exact amount of information necessary to compute the factorization of u. Along the way, we prove some uniform computability results for Blaschke products; these results play a key role in the analysis of factorization. We also give some computability results concerning zeros and singularities of analytic functions. We use Type‐Two Effectivity as our foundation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rose‐Like Microstructures of Polyaniline by Using a Simplified Template‐Free Method under a High Relative Humidity
Authors: Zhu Ying , He Haiyong , Wan Meixiang , Jiang Lei 
Published: August 2008

Abstract3‐D rose‐like microstructures of polyaniline (PANI), which are self‐assembled from 2‐D nanosheets consisted of 1‐D nanofibers, were synthesized by a template‐free method in the presence of ammonium peroxydisulfate (APS) as both oxidant and dopant under a high relative humidity of 80% for the first time. When the relative humidity increases from 25 to 80%, not only morphology of the micro/nanostructured PANI undergoes a change from 1‐D nanofibers to 2‐D nanosheets to 3‐D rose‐like microstructures, but also increase in crystallinity. It is proposed that a cooperation effect of the oriented water molecules at the vapor–water interface and difference in hydrogen bonding energies between the interface and the bulk induced by the relative high humidity results in the formation of the 3‐D rose‐like microstructures self‐assembled from 2‐D nanosheets. Moreover, the method reported may provide a simple approach for understanding self‐assembly of complex micro/nanostructures of PANI.magnified image
Susceptibility gradient mapping (SGM): A new postprocessing method for positive contrast generation applied to superparamagnetic iron oxide particle (SPIO)‐labeled cells
Authors: Dahnke Hannes , Liu Wei , Herzka Daniel , Frank Joseph A. , Schaeffter Tobias 
Published: August 2008

AbstractLocal susceptibility gradients result in a dephasing of the precessing magnetic moments and thus in a fast decay of the NMR signals. In particular, cells labeled with superparamagnetic iron oxide particles (SPIOs) induce hypointensities, making the in vivo detection of labeled cells from such a negative image contrast difficult. In this work, a new method is proposed to selectively turn this negative contrast into a positive contrast. The proposed method calculates the susceptibility gradient and visualizes it in a parametric map directly from a regular gradient‐echo image dataset. The susceptibility gradient map is determined in a postprocessing step, requiring no dedicated pulse sequences or adaptation of the sequence before and during image acquisition. Phantom experiments demonstrated that local susceptibility differences can be quantified. In vivo experiments showed the feasibility of the method for tracking of SPIO‐labeled cells. The method bears the potential also for usage in other applications, including the detection of contrast agents and interventional devices as well as metal implants. Magn Reson Med 60:595–603, 2008. © 2007 Wiley‐Liss, Inc.
Image‐based coronary tracking and beat‐to‐beat motion compensation: Feasibility for improving coronary MR angiography
Authors: Dewan Maneesh , Hager Gregory D. , Lorenz Christine H. 
Published: August 2008

AbstractA method to reduce the effect of motion variability in MRI of the coronary arteries is proposed. It involves acquiring real‐time low‐resolution images in specific orthogonal orientations, extracting coronary motion from these images, and then using this motion information to guide high‐resolution MR image acquisition on a beat‐to‐beat basis. The present study establishes the feasibility and efficacy of the proposed approach using human motion data in an offline implementation, prior to future online implementation on an MRI scanner. To track the coronary arteries in low‐resolution real‐time MR images in an accurate manner, a tracking approach is presented and validated. The tracking algorithm was run on real‐time images acquired at 15–20 frames per second in four‐chamber, short‐axis, and coronal views in five volunteers. The systolic and diastolic periods in the cardiac cycles, computed from the extracted motion information, had significant variability during the short time periods typical of cardiac MRI. It is also demonstrated through simulation analysis using human tracked coronary motion data that accounting for this cardiac variability by adaptively changing the trigger delay for acquisition on a beat‐to‐beat basis improves overall motion compensation and hence MR image quality evaluated in terms of SNR and CNR values. Magn Reson Med 60:604–615, 2008. © 2008 Wiley‐Liss, Inc.
Magnetization transfer induced biexponential longitudinal relaxation
Authors: Prantner Andrew M. , Bretthorst G. Larry , Neil Jeffrey J. , Garbow Joel R. , Ackerman Joseph J.H. 
Published: August 2008

AbstractLongitudinal relaxation of brain water 1H magnetization in mammalian brain in vivo is typically analyzed on a per‐voxel basis using a monoexponential model, thereby assigning a single relaxation time constant to all 1H magnetization within a given voxel. This approach was tested by obtaining inversion recovery (IR) data from gray matter of rats at 64 exponentially spaced recovery times. Using Bayesian probability for model selection, brain water data were best represented by a biexponential function characterized by fast and slow relaxation components. At 4.7T, the amplitude fraction of the rapidly relaxing component is 3.4% ± 0.7% with a rate constant of 44 ± 12 s−1 (mean ± SD; 174 voxels from four rats). The rate constant of the slow relaxing component is 0.66 ± 0.04 s−1. At 11.7T, the corresponding values are 6.9% ± 0.9%, 19 ± 5 s−1, and 0.48 ± 0.02 s−1 (151 voxels from four rats). Several putative mechanisms for biexponential relaxation behavior were evaluated, and magnetization transfer (MT) between bulk water protons and nonaqueous protons was determined to be the source of biexponential longitudinal relaxation. MR methods requiring accurate quantification of longitudinal relaxation may need to take this effect explicitly into account. Magn Reson Med 60:555–563, 2008. © 2008 Wiley‐Liss, Inc.
Inferring multiple maxima in intravoxel white matter fiber distribution
Authors: Canales‐Rodríguez Erick Jorge , Melie‐García Lester , Iturria‐Medina Yasser , Martínez‐Montes Eduardo , Alemán‐Gómez Yasser , Lin Ching‐Po 
Published: August 2008

AbstractA new methodology is introduced that characterizes the intravoxel orientation distribution function (ODF) based on a single‐fiber model of the diffusion MRI signal. Using a Bayesian framework the probability of finding a fiber in a specific orientation is obtained. The proposed ODF estimation relies on a cigar‐like diffusion tensor model, the methodology is thus denominated Bayesian cigar‐like diffusion tensor (BCDT). This work makes two major contributions: 1) the study of single‐fiber models in detecting fibers with different volume fractions in a voxel, and 2) the introduction of the Nth‐root correction to improve the detection of fibers with smaller volume fractions, where N is the number of diffusion MRI measurements. It is demonstrated that the incomplete signal modeling fails to reconstruct the relative fiber volume fractions, especially when the intravoxel diffusion profiles have dissimilar contributions to the diffusion MRI signal. In this situation the fibers with smaller contributions are hardly detectable. The BCDT method proposed here reduces this effect by introducing the Nth‐root correction, making multiple fibers estimable. The performance of the new methodology is illustrated using synthetic and real data, as well as the data from a phantom of intersecting capillaries. Magn Reson Med 60:616–630, 2008. © 2008 Wiley‐Liss, Inc.
Rapid radiofrequency field mapping in vivo using single‐shot STEAM MRI
Authors: Helms Gunther , Finsterbusch Jürgen , Weiskopf Nikolaus , Dechent Peter 
Published: August 2008

AbstractHigher field strengths entail less homogeneous RF fields. This may influence quantitative MRI and MRS. A method for rapidly mapping the RF field in the human head with minimal distortion was developed on the basis of a single‐shot stimulated echo acquisition mode (STEAM) sequence. The flip angle of the second RF pulse in the STEAM preparation was set to 60° and 100° instead of 90°, inducing a flip angle‐dependent signal change. A quadratic approximation of this trigonometric signal dependence together with a calibration accounting for slice excitation‐related bias allowed for directly determining the RF field from the two measurements only. RF maps down to the level of the medulla could be obtained in less than 1 min and registered to anatomical volumes by means of the T2‐weighted STEAM images. Flip angles between 75% and 125% of the nominal value were measured in line with other methods. Magn Reson Med 60:739–743, 2008. © 2008 Wiley‐Liss, Inc.