bluuebunny/crossref_metadata_2025_split huggingface dataset:
A multispectral three‐dimensional acquisition technique for imaging near metal implants
Authors: Koch Kevin M. , Lorbiecki John E. , Hinks R. Scott , King Kevin F. 
Published: January 2009

AbstractMetallic implants used in bone and joint arthroplasty induce severe spatial perturbations to the B0 magnetic field used for high‐field clinical magnetic resonance. These perturbations distort slice‐selection and frequency encoding processes applied in conventional two‐dimensional MRI techniques and hinder the diagnosis of complications from arthroplasty. Here, a method is presented whereby multiple three‐dimensional fast‐spin‐echo images are collected using discrete offsets in RF transmission and reception frequency. It is demonstrated that this multi acquisition variable‐resonance image combination technique can be used to generate a composite image that is devoid of slice‐plane distortion and possesses greatly reduced distortions in the readout direction, even in the immediate vicinity of metallic implants. Magn Reson Med 61:381–390, 2009. © 2009 Wiley‐Liss, Inc.
Improved residue function and reduced flow dependence in MR perfusion using least‐absolute‐deviation regularization
Authors: Wong Kelvin K. , Tam Chi‐Pan , Ng Michael , Wong Stephen T.C. , Young Geoffrey S. 
Published: January 2009

AbstractCerebral blood flow (CBF) estimates derived from singular value decomposition (SVD) of time intensity curves from Gadolinium bolus perfusion‐weighted imaging are known to underestimate CBF, especially at high flow rates. We report the development of a model‐independent delay‐invariant deconvolution technique using least‐absolute‐deviation (LAD) regularization to improve the CBF estimation accuracy. Computer simulations were performed to compare the accuracy of CBF estimates derived from LAD, reformulated SVD (rSVD) and standard SVD (sSVD) techniques. Simulations were performed at image signal‐to‐noise ratios ranging from 20 to 400, cerebral blood volumes from 1% to 10%, and CBF from 2.5 mL/100 g/min to 176.5 mL/100 g/min to estimate the effect of these parameters on the accuracy of CBF estimation. The LAD method improved the CBF estimation accuracy by up to 32% in gray matter and 23% in white matter compared with rSVD and sSVD methods. LAD method also reduces the systematic bias of rSVD and sSVD methods to baseline SNR while producing more accurate and reproducible residue function calculation than either rSVD or sSVD method. Initial clinical implementation of the method on six representative clinical cases confirm the advantages of the LAD method over rSVD and sSVD methods. Magn Reson Med 61:418–428, 2009. © 2009 Wiley‐Liss, Inc.
Mechanically adjustable coil array for wrist MRI
Authors: Nordmeyer‐Massner J.A. , De Zanche N. , Pruessmann K.P. 
Published: January 2009

AbstractIn this work, the concept of mechanically adjustable MR receiver coil arrays is proposed and implemented for the specific case of human wrist imaging. An eight‐channel wrist array for proton MRI at 3 Tesla was constructed and evaluated. The array adjusts to the individual anatomy by a mechanism that fits a configuration of flexible coil elements closely around the wrist. With such adjustability, it is challenging to ensure robust electrical behavior and signal‐to‐noise (SNR) performance. These requirements are met by preamplifier decoupling and a suitable matching strategy based on π networks that render the coil responses robust against changes in tuning, loading and mutual coupling. The robustness of the resulting SNR yield was studied by varying the effective coil matching over a wide range in a phantom imaging experiment. While SNR variation of up to 25% was observed at the surface of the phantom the SNR was essentially constant in the critical center region. A second SNR study in wrist phantoms of different sizes confirmed the benefits of bringing the coil elements very close, up to 3 mm, to the individual target volume. These findings were supported by initial in vivo imaging, exploiting high‐sensitivity detection for highly resolved structural imaging. Magn Reson Med 61:429–438, 2009. © 2009 Wiley‐Liss, Inc.
Simultaneous z‐shim method for reducing susceptibility artifacts with multiple transmitters
Authors: Deng Weiran , Yang Cungeng , Alagappan Vijayanand , Wald Lawrence L. , Boada Fernando E. , Stenger V. Andrew 
Published: January 2009

AbstractThe signal loss susceptibility artifact is a major limitation in gradient‐echo MRI applications. Various methods, including z‐shim techniques and multidimensional tailored radio frequency (RF) pulses, have been proposed to mitigate the through‐plane signal loss artifact, which is dominant in axial slices above the sinus region. Unfortunately, z‐shim techniques require multiple steps and multidimensional RF methods are complex, with long pulse lengths. Parallel transmission methods were recently shown to be promising for improving B1 inhomogeneity and reducing the specific absorption rate. In this work, a novel method using time‐shifted slice‐select RF pulses is presented for reducing the through‐plane signal loss artifact in parallel transmission applications. A simultaneous z‐shim is obtained by concurrently applying unique time‐shifted pulses on each transmitter. The method is shown to reduce the signal loss susceptibility artifact in gradient‐echo images using a four‐channel parallel transmission system at 3T. Magn Reson Med 61:255–259, 2009. © 2009 Wiley‐Liss, Inc.
Healthcare‐associated Infections: Epidemiology, Prevention, and Therapy
Authors: Doshi Rupali K. , Patel Gopi , MacKay Richard , Wallach Frances 
Published: January 2009

AbstractReducing nosocomial infection rates is a major component of healthcare improvement. This article reviews the epidemiology, prevention, and therapy for some of the most common healthcare‐associated infections, including central line–associated bloodstream infections and catheter‐associated urinary tract infections, and 3 common organisms: methicillin‐resistant Staphylococcus aureus, multidrug‐ resistant gram‐negative bacteria, and Clostridium difficile. Mt Sinai J Med 76:84–94, © 2009 Mount Sinai School of Medicine
Spectrum of Fibrosing Diffuse Parenchymal Lung Disease
Authors: Morgenthau Adam S. , Padilla Maria L. 
Published: January 2009

AbstractThe interstitial lung diseases are a heterogeneous group of disorders characterized by inflammation and/or fibrosis of the pulmonary interstitium. In 2002, the American Thoracic Society and the European Respiratory Society revised the classification of interstitial lung diseases and introduced the term diffuse parenchymal lung disease. The idiopathic interstitial pneumonias are a subtype of diffuse parenchymal lung disease. The idiopathic interstitial pneumonias are subdivided into usual interstitial pneumonia (with its clinical counterpart idiopathic interstitial pneumonia), nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, acute interstitial pneumonia, desquamative interstitial pneumonia, respiratory bronchiolitis interstitial lung disease, and lymphocytic pneumonia. Sarcoidosis and hypersensitivity pneumonitis are the 2 most common granulomatous diffuse parenchymal lung diseases. Rheumatoid arthritis, systemic sclerosis, and dermatomyositis/polymyositis (causing antisynthetase syndrome) are diffuse parenchymal lung diseases of known association because these conditions are associated with connective tissue disease. Hermansky‐Pudlak syndrome is a rare genetic diffuse parenchymal lung disease characterized by the clinical triad of pulmonary disease, oculocutaneous albinism, and bleeding diathesis. This review provides an overview of the chronic fibrosing diffuse parenchymal lung diseases. Its primary objective is to illuminate the clinical challenges encountered by clinicians who manage the diffuse parenchymal lung diseases regularly and to offer potential solutions to those challenges. Treatment for the diffuse parenchymal lung diseases is limited, and for many patients with end‐stage disease, lung transplantation remains the best option. Although much has been learned about the diffuse parenchymal lung diseases during the past decade, research in these diseases is urgently needed. Mt Sinai J Med 76:2–23, © 2009 Mount Sinai School of Medicine
Gastroesophageal Reflux Disease and Idiopathic Pulmonary Fibrosis
Authors: Pashinsky Yevgenia Y. , Jaffin Barry W. , Litle Virginia R. 
Published: January 2009

AbstractGastroesophageal reflux disease occurs with a higher prevalence in patients with idiopathic pulmonary fibrosis than in matched controls. Silent reflux occurs in about a third of patients with significant gastroesophageal reflux disease; thus, objective measurements are required to evaluate gastroesophageal reflux disease in patients with advanced lung diseases. We provide here a detailed description of acid and non‐acid reflux and the diagnostic evaluation for pulmonologists and lung transplant surgeons suspecting reflux as a contributing factor in advanced lung diseases. We review the evidence for gastroesophageal reflux disease causing idiopathic pulmonary fibrosis and other select pulmonary diseases and the potential role of antireflux surgery in the management of advanced lung disease and transplant patients. Mt Sinai J Med 76:24–29, © 2009 Mount Sinai School of Medicine
High Resolution Computed Tomography in Idiopathic Interstitial Pneumonias
Authors: Argiriadi Pamela A. , Mendelson David S. 
Published: January 2009

AbstractIn June 2001, using an “international multidisciplinary consensus,” the American Thoracic Society and European Respiratory Society classified the idiopathic interstitial pneumonias (Am J Respir Crit Care Med 2002;165:277–304). The American Thoracic Society and European Respiratory Society coined the term idiopathic interstitial pneumonias because the diseases in question have both unknown etiologies and various combinations of inflammation and fibrosis within the lung parenchyma. The consensus included the development of a classification standard of the interstitial pneumonias and discussed the role of surgical lung biopsy and bronchoalveolar lavage evaluation. The classification of idiopathic interstitial pneumonias is based on histologic criteria, which correlate to imaging patterns on high‐resolution computed tomography. The group of lung diseases under the umbrella of idiopathic interstitial pneumonias includes the following: usual interstitial pneumonia, nonspecific interstitial pneumonia, desquamative interstitial pneumonia, respiratory bronchiolitis interstitial lung disease, acute interstitial pneumonia, cryptogenic organizing pneumonia, and lymphoid interstitial pneumonia. Mt Sinai J Med 76:37–52, © 2009 Mount Sinai School of Medicine
“End‐stage” Pulmonary Fibrosis in Sarcoidosis
Authors: Teirstein Alvin T. , Morgenthau Adam S. 
Published: January 2009

AbstractPulmonary fibrosis is an unusual “end stage” in patients with sarcoidosis. Fibrosis occurs in a minority of patients, and presents with a unique physiologic combination of airways dysfunction (obstruction) superimposed on the more common restrictive dysfunction. Imagin techniques are essential to the diagnosis, assessment and treatment of pulmonary fibrosis. Standard chest radiographs and CT scans may reveal streaks, bullae, cephalad retraction of the hilar areas, deviation of the trachea and tented diaphragm. Positive gallium and PET scans indicate residual reversible granulomatous disease and are important guides to therapy decisions. Treatment, usually with corticosteroids, is effective in those patients with positive scans, but fibrosis does not improve with any treatment. With severe functional impariment and patient disability, pulmonary hypertension and right heart failure may supervene for which the patient will require treatment. Oxygen, careful diuresis, sildenafil and bosentan may be salutary. These patients are candidates for lung transplantation. Mt Sinai J Med 76:30–36, © 2009 Mount Sinai School of Medicine
Proton spectroscopic imaging of the human prostate at 7 T
Authors: Klomp D. W. J. , Bitz A. K. , Heerschap A. , Scheenen T. W. J. 
Published: January 2009

AbstractThe sensitivity of proton MR Spectroscopic Imaging (1H‐MRSI) of the prostate can be optimized by using the high magnetic field strength of 7 T in combination with an endorectal coil. In the work described in this paper we introduce an endorectal transceiver at 7 T, validate its safety for in vivo use and apply a pulse sequence, optimized for three‐dimensional (3D) 1H‐MRSI of the human prostate at 7 T. A transmit/receive endorectal RF coil was adapted from a commercially available 3 T endorectal receive‐only coil and validated to remain within safety guidelines for radiofrequency (RF) power deposition using numerical models, MR thermometry of phantoms, and in vivo temperature measurements. The 1H‐MRSI pulse sequence used adiabatic slice selective refocusing pulses and frequency‐selective water and lipid suppression to selectively obtain the relevant metabolite signals from the prostate. Quantum mechanical simulations were used to adjust the inter‐pulse timing for optimal detection of the strongly coupled spin system of citrate resulting in an echo time of 56 ms. Using this endorectal transceiver and pulse sequence with slice selective adiabatic refocusing pulses, 3D 1H‐MRSI of the human prostate is feasible at 7 T with a repetition time of 2 s. The optimized inter‐pulse timing enables the absorptive detection of resonances of spins from spermine and citrate in phase with creatine and choline. These potential tumor markers may improve the in vivo detection, localization, and assessment of prostate cancer. Copyright © 2009 John Wiley & Sons, Ltd.
“Life grows between the rocks”: Latino adolescents' and parents' perspectives on mental health stressors
Authors: Garcia Carolyn , Lindgren Sandi 
Published: January 2009

AbstractLatino adolescents, an increasingly larger proportion of youth in the US, are at special risk for mental health problems, including depression and suicidal ideation. Little is known about the meaning of mental health stressors for Latino adolescents and their parents. We conducted a descriptive study to elicit Latino adolescents' and parents' perspectives regarding mental health stressors as a basis for future preventive interventions. Eight focus groups were conducted with 53 Latino participants, 2 per sub‐group (boys, girls, mothers, fathers). Three categories of mental health stressors included discrimination, immigration, and familial disconnection. Findings support the need for collaborative interventions and multi‐level strategies (individual, family, and community) to address stressors in Latino adolescents' experiences. © 2009 Wiley Periodicals, Inc. Res Nurs Health 32:148–162, 2009
Liquid crystalline polycarbosilanes and poly(di‐n‐butylsiloxane) as stationary phases in gas chromatography
Authors: Ganicz Tomasz , Stańczyk Wladyslaw Andrzej , Chmielecka Jadwiga , Kowalski Jozef 
Published: January 2009

AbstractBACKGROUND: Due to their wide variety of applicable substituents and relative ease of synthesis, liquid crystalline polymers are extensively studied as stationary phases in gas–liquid chromatography (GC). Although side‐chain liquid crystalline polycarbosilanes, due to their higher thermal and chemical stability compared to polysiloxanes, seem to be natural candidates for GC stationary phases, they have not yet been tested for such applications.RESULTS: Five stationary phases for GC, based on liquid crystalline polycarbosilanes and polysiloxanes, capable of generating nematic, smectic and condis mesophases were studied. HETP values and Kováts retention indices were calculated, using a series of probes (linear alkenes, benzene, xylene, toluene, cumene, mesitylene), and compared with those obtained for a typical stationary phase based on polydimethylsiloxane (OV‐101). The separation abilities of polycarbosilanes and poly(di‐n‐butylsiloxane) were evaluated using inverse gas chromatography.CONCLUSION: The results suggest that polycarbosilane‐based phases have similar separation properties to those of polysiloxane liquid crystals with some advantages such as higher thermal and chemical stability and good, linear dependence of retention times on temperature. The poly(di‐n‐butylsiloxane)‐based phase did not exhibit any advantages over the typical OV‐101 phase. Copyright © 2009 Society of Chemical Industry
Predictions of peptides' retention times in reversed‐phase liquid chromatography as a new supportive tool to improve protein identification in proteomics
Authors: Bączek Tomasz , Kaliszan Roman 
Published: January 2009

AbstractOne of the initial steps of proteomic analysis is peptide separation. However, little information from RP‐HPLC, employed for peptides separation, is utilized in proteomics. Meanwhile, prediction of the retention time for a given peptide, combined with routine MS/MS data analysis, could help to improve the confidence of peptide identifications. Recently, a number of models has been proposed to characterize quantitatively the structure of a peptide and to predict its gradient RP‐HPLC retention at given separation conditions. The chromatographic behavior of peptides has usually been related to their amino acid composition. However, different values of retention coefficients of the same amino acid in different peptides at different neighborhoods were commonly observed. Therefore, specific retention coefficients were derived by regression analysis or by artificial neural networks (ANNs) with the use of a set of peptides retention. In the review, various approaches for peptide elution time prediction in RP‐HPLC are presented and critically discussed. The contribution of sequence dependent parameters (e.g., amphipathicity or peptide sequence) and peptide physicochemical descriptors (e.g., hydrophobicity or peptide length) that have been shown to affect the peptide retention time in LC are considered and analyzed. The predictive capability of the retention time prediction models based on quantitative structure–retention relationships (QSRRs) are discussed in details. Advantages and limitations of various retention prediction strategies are identified. It is concluded that proper processing of chromatographic data by statistical learning techniques can result in information of direct use for proteomics, which is otherwise wasted.
Water‐soluble polymers from acid‐functionalized norbornenes
Authors: Lienkamp Karen , Kins Christoph F. , Alfred Sterling F. , Madkour Ahmad E. , Tew Gregory N. 
Published: January 2009

AbstractUnprotected exo,exo‐5‐norbornene‐2,3‐dicarboxylic acid and exo,exo‐7‐oxa‐5‐norbornene‐2,3‐dicarboxylic acid were polymerized via ring‐opening metathesis polymerization. This reaction yielded polymers with molecular weights (Mn from GPC) ranging from 31 to 242 kg/mol and polydispersity indices between 1.05 and 1.12, using Grubbs' third generation catalyst. The water solubility as a function of pH value of the polymers was investigated by dynamic light scattering (DLS). DLS and acid‐base titration revealed that the oxanorbornene polymer was water soluble over a wider pH range than its norbornene analog. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1266–1273, 2009
Synthesis of high‐molecular‐weight linear methacrylate copolymers with spiropyran side groups: Conformational changes of single molecules in solution and on surfaces
Authors: Adelmann Ronald , Mela Petra , Gallyamov Marat O. , Keul Helmut , Möller Martin 
Published: January 2009

AbstractP(BMA‐co‐HEMA‐spiropyran) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization of butyl methacrylate (BMA) and 2‐(trimethylsilyloxy)‐ethyl methacrylate (HEMA‐TMS), removal of the TMS‐protective groups, and the polymer analogous esterification of the hydroxyethyl side chains with a spiropyran containing a carboxylic acid group. UV‐induced conformational changes of the synthesized macromolecules and low‐molecular‐weight spiropyran molecules were studied. Rate constants and half‐life times of the ring closure reaction from zwitterionic merocyanine to the spiropyran species were determined in the presence and absence of mica‐dispersed particles in toluene both with the free spiropyran and the polymer‐bound spiropyran. Scanning force microscopy was used to visualize the conformation of spiropyran‐decorated single macromolecular chains and agglomerated polymer‐bound merocyanine adsorbed on mica. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1274–1283, 2009
The study of electroactive block copolymer containing aniline pentamer isolated from different solvents
Authors: Hu Jun , Huang Lihong , Lang Le , Liu Yadong , Zhuang Xiuli , Chen Xuesi , Wei Yen , Jing Xiabin 
Published: January 2009

AbstractFor the films and powder of polymers containing conductive oligomer are usually obtained from solution, the choice of better solvents for the regular arrangement of oligomers is very important for the higher conductivity. Because of the poor solubility of the oligomers, it is difficult to study the arrangement directly in most common solvents, so, we synthesized a triblock copolymer, mPEG2k‐aniline pentamer‐mPEG2k, as the model to investigate the arrangement–solvent relationship. For the poor solubility of the AP block in common solvents, the copolymer self‐assembled into spheric micelles in toluene and into lamellar crystals in water and THF. The crystallinity (Xc) and crystallization temperature (Tc) values of mPEG blocks in powders prepared from different solvents differed obviously, which may be the effect of different self‐assembled structures. From the two‐phase model of one‐dimensional electron density correlation function of SAXS, the long period of copolymer prepared from THF was presumably equal to the long period of pure mPEG plus the chain length of AP, which demonstrates that the AP blocks arrange regularly in the noncrystalline regions. In the selected solvents, the ones with higher polarity and better solubility induced more regular arrangement of AP blocks, which may be useful for choosing solvents for preparation of higher conductivity polymers' films containing aniline oligomers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1298–1307, 2009
Synthesis and characterization of star graft copolymers with asymmetric mixed “V‐shaped” side chains via “click” chemistry on a hyperbranched polyglycerol core
Authors: Wang Guowei , Liu Chao , Pan Mugang , Huang Junlian 
Published: January 2009

AbstractThe star graft copolymers composed of hyperbranched polyglycerol (HPG) as core and well defined asymmetric mixed “V‐shaped” identical polystyrene (PS) and poly(tert‐butyl acrylate) as side chains were synthesized via the “click” chemistry. The V‐shaped side chain bearing a “clickable” alkyne group at the conjunction point of two blocks was first prepared through the combination of anionic polymerization of styrene (St) and atom transfer radical polymerization of tert‐butyl acrylate (tBA) monomer, and then “click” chemistry was conducted between the alkyne groups on the side chains and azide groups on HPG core. The obtained star graft copolymers and intermediates were characterized by gel permeation chromatography (GPC), GPC equipped with a multiangle laser‐light scattering detector (GPC‐MALLS), nuclear magnetic resonance spectroscopy and fourier transform infrared. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1308–1316, 2009