bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural D‐glucose as a biodegradable MRI contrast agent for detecting cancer
Authors: Chan Kannie W. Y. , McMahon Michael T. , Kato Yoshinori , Liu Guanshu , Bulte Jeff W. M. , Bhujwalla Zaver M. , Artemov Dmitri , van Zijl Peter C. M. 
Published: October 2012

AbstractPurpose:Modern imaging technologies such as CT, PET, SPECT, and MRI employ contrast agents to visualize the tumor microenvironment, providing information on malignancy and response to treatment. Currently, all clinical imaging agents require chemical labeling, i.e. with iodine (CT), radioisotopes (PET/SPECT), or paramagnetic metals (MRI). The goal was to explore the possibility of using simple D‐glucose as an infusable biodegradable MRI agent for cancer detection.Methods:D‐glucose signals were detected using chemical exchange saturation transfer (glucoCEST) MRI of its hydroxyl groups. Feasibility was established in phantoms as well as in vivo using two human breast cancer cell lines, MDA‐MB‐231 and MCF‐7, implanted orthotopically in nude mice. PET and contrast‐enhanced MRI were also acquired.Results:Both tumor types exhibited significant glucoCEST signal enhancement during systemic sugar infusion (mild hyperglycemia), allowing their noninvasive visualization. GlucoCEST showed differences between types, while PET and CE‐MRI did not. Data are discussed in terms of signal contributions from the increased vascular volume in tumors and especially from the acidic extracellular extravascular space (EES), where glucoCEST signal is expected to be enhanced due to a slow down of hydroxyl proton exchange.Conclusions:This observation opens up the possibility for using simple non‐toxic sugars as contrast agents for cancer detection with MRI by employing hydroxyl protons as a natural label. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Fractional order constitutive model of geomaterials under the condition of triaxial test
Authors: Yin Deshun , Wu Hao , Cheng Chen , Chen YangQuan 
Published: October 2012

SUMMARYFractional calculus has been successfully applied to characterize the rheological property of viscoelastic materials; however, geomaterials were seldom involved in fractional order constitutive models (FOCM), and the topic of first loading and then unloading is rarely discussed through fractional calculus. In this paper, mechanical properties are considered as a ‘spectrum’, both ends of which are elasticity and viscosity, and the fractional order can be utilized to describe such properties quantitatively. In addition to conditions such as creep, stress‐relaxation, and constant‐strain‐rate loading, stress‐strain relationship under the condition of first loading and then unloading was also derived using FOCM. FOCM is then adopted to simulate triaxial tests of geomaterials under corresponding conditions. A comparison of test and numerical results demonstrates that FOCM can reasonably describe the mechanical characteristics of geomaterials.Copyright © 2012 John Wiley & Sons, Ltd.
Evaluation of Clinical and Safety Outcomes Associated with Conversion from Brand‐Name to Generic Tacrolimus in Transplant Recipients Enrolled in an Integrated Health Care System
Authors: Spence Michele M. , Nguyen Lynda M. , Hui Rita L. , Chan James 
Published: October 2012

Study ObjectiveTo evaluate clinical and safety outcomes among transplant recipients whose tacrolimus was converted from the brand‐name formulation to a generic formulation.DesignRetrospective analysis.Data SourceClinical databases and electronic records from a large, integrated health care system in California.PatientsA total of 234 clinically stable, adult transplant recipients (renal, liver, and heart) whose tacrolimus was converted from the brand‐name formulation to a generic formulation between October 1, 2010, and December 31, 2010, according to a physician‐approved protocol.Measurements and Main ResultsFor each patient, pre‐ and postconversion tacrolimus trough concentrations and serum creatinine concentrations were analyzed. Data were also collected on the percentage of patients who required dosage titration, drug cost savings, and rates of reversion to brand‐name tacrolimus, biopsy‐proved acute allograft rejections, and mortality. No significant differences were noted in mean ± SD pre‐ and postconversion tacrolimus trough levels (6.74 ± 1.61 vs 6.96 ± 2.31 ng/ml, p=0.137) or serum creatinine concentrations (1.33 ± 0.48 vs 1.36 ± 0.82 mg/dl, p=0.302). The mean ± SD percent change in tacrolimus trough concentration was 5.63 ± 32.95%. Thirty‐six patients (15.4%) required dosage titration. Six patients (2.6%) reverted back to brand‐name tacrolimus. No deaths or acute rejections occurred. Use of the generic product saved each patient an average of $45/month in drug acquisition cost and $26/prescription copayment.ConclusionClinical experience as well as research data show that use of generic tacrolimus results in trough concentrations that are comparable to the brand‐name drug. Given the lack of adverse events reported and the cost savings recognized, conversion from brand‐name tacrolimus to generic tacrolimus should be encouraged. Since dosage titration may be required, close therapeutic drug monitoring is recommended.
Sequential interpenetrating poly(ethylene glycol) hydrogels prepared by UV‐initiated thiol–ene coupling chemistry
Authors: Yang Ting , Malkoch Michael , Hult Anders 
Published: October 2012

AbstractPoly(ethylene glycol) (PEG)‐diallyls, ranging from 2 to 8 kDa, were successfully reacted with a trifunctional thiol crosslinker via thiol–ene coupling reaction to construct four different primary PEG hydrogels. These systems were used as scaffolds for the preparation of a library of sequential interpenetrating networks (SeqIPNs). The solid content of the secondary networks varied between 21 and 34% and was dependent on the length of the absorbing PEGs. The gel fractions for the IPNs were above 85%. Additionally, the lowest degree of swelling was found for the IPN based on 2‐kDa PEG (315%), whereas the 8‐kDa PEG IPN exhibited a value of 810%. The SeqIPN strategy facilitated hydrogel systems that cover a larger domain of tensile modulus (192–889 kPa) when compared with single hydrogel networks (175–555 kPa). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Interactions of cartilage extracellular matrix macromolecules
Authors: Horkay Ferenc 
Published: October 2012

AbstractArticular cartilage is a low‐friction, load‐bearing tissue located at joint surfaces. The extracellular matrix (ECM) of cartilage consists of a fibrous collagen network, which is prestressed by the osmotic swelling pressure exerted by negatively charged proteoglycan (PG) aggregates embedded in the collagen network. The major PG is the bottlebrush‐shaped aggrecan, which forms complexes with linear hyaluronic acid (HA) chains. We quantify microscopic and macroscopic changes resulting from self‐assembly between aggrecan and HA using a complementary set of physical measurements to determine structure and interactions by combining scattering techniques, including small‐angle X‐ray scattering, small‐angle neutron scattering, and dynamic light scattering with macroscopic osmotic pressure measurements. It is demonstrated that the osmotic pressure that defines the load‐bearing ability of cartilage is primarily governed by the main macromolecular components (aggrecan and collagen) of the ECM. Knowledge of the interactions between the macromolecular components of cartilage ECM is essential to understand biological function and to develop successful tissue engineering strategies for cartilage repair. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Mechanism of surface pre‐treatments and modification for dye‐sensitized solar cells
Authors: Hu Linhua , Mo Li’e , Li Wenxin , Fang Xiaqin , Dai Songyuan 
Published: October 2012

AbstractThe influence of the TiCl4 solution treatment on nanocrystalline TiO2 films in dye‐sensitized solar cells (DSC) was investigated and compared with the untreated films by Intensity‐modulated photocurrent spectroscopy (IMPS) and Intensity‐modulated photovoltage spectroscopy (IMVS). The IMPS and IMVS experimental results indicated that the electron lifetime (τn), the diffusion coefficient (Dn), the diffusion length (Ln), the incident photo‐to‐current conversion efficiency (IPCE) and the electric charge (Qoc) in open‐circuit of the treated DSC were increased while the electron transit time (τd) decreased comparing with those of the untreated one. The electron generation, transportation, recombination rates and the electron collecting efficiency have been remarkably improved after treating. The properties of the electron generation, transport and recombination under different illumination intensities which were also investigated by IMPS/IMVS were accordant with the results reported in previous literature (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wavelength‐modulated excitonic spectra in green series of Cu2O thin films sandwiched by MgO plates
Authors: Iwamitsu Kazunori , Aihara Shingo , Shimamoto Tomoshige , Fujii Atsuhiro , Akai Ichiro 
Published: October 2012

AbstractIn order to clarify uniaxial stress effects on a green excitonic series in Cu2O, we measured temperature dependence of wavelength modulated (WM) absorption spectra of a Cu2O thin film sandwiched by MgO plates. In these spectra, excitonic resonances of 2P∼4P states are clearly observed even at 180 K. From these resonance spectral structures at each temperature, it is found that the band gap of the green series shifts to lower energy side than that of bulk crystals and the red shift becomes obvious with cooling down to 7 K. These results indicate that the trapping potential for the green excitons is formed by the uniaxial stress due to a lattice mismatch between the Cu2O and MgO (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sub‐gap absorption study of SnS films deposited by thermal evaporation of sulfurized Sn powder
Authors: Gotoh Tamihiro 
Published: October 2012

AbstractOptical absorption spectra of thermally evaporated SnS films were examined by optical transmittance and photothermal spectroscopy using individual cantilever. The SnS films exhibit optical bandgap of 1.30‐1.36 eV for indirect or nondirect transitions, Urbach energy of 0.12‐0.14 eV and mid‐gap absorption at 0.5‐1.2 eV. The slight decrease of bandgap was observed for the annealed films in vacuum. The mid‐gap absorption was reduced to less than 2% of as‐deposited films by thermal annealing up to 400 °C. These results indicate that heat‐induced structural change causes the reduction of gap‐states in SnS films. Photothermal spectroscopy using individual cantilever is useful for the quality monitoring of semiconducting SnS films (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoinduced mass transport in amorphous As‐S‐Se films
Authors: Reinfelde Mara , Grants Rolands , Teteris Janis 
Published: October 2012

AbstractDirect surface patterning due to photoinduced mass transport in amorphous As‐S‐Se films has been studied. Illumination of the films with two orthogonally (±45°) polarized beam interference pattern causes the formation of surface relief gratings on the films due to lateral mass transport regarding to light propagation direction. The obtained experimental results showed the dependence of photoinduced surface relief depth (Δh) on film thickness during holographic recording from film side as well as from glass substrate side. After constant exposure doses for the films with a thickness d < 1 μm a strong dependence of Δh on film thickness was observed. For films with a thickness d > 1 μm values of Δh do not depend significantly on the film thickness for recording from film side but decrease rapidly for recording from opposite side. The studies of the surface relief grating formation dependence on the film thickness show that all illuminated film volume is involved in mass transport process (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Performance of blue fluorescence and red phosphorescent organic light‐emitting diodes using a molecular material with high hole drift mobility
Authors: Oshiro Tomoyuki , Tamura Takeshi , Kageyama Hiroshi , Shirota Yasuhiko , Kajii Hirotake , Ohmori Yutaka 
Published: October 2012

AbstractThis study focuses on the carrier balance factor and transient characteristics of organic light‐emitting diodes (OLEDs) utilizing tris[4‐(5‐phenylthiophen‐2‐yl)phenyl] amine (TPTPA) as a blue emissive material or a host material of a red phosphorescent dye, which exhibits the highest level of hole drift mobility (µ = 1.0×10‐2 cm2V‐1s‐1) among those reported for organic disordered systems. We investigated the doping effect of a red phos‐phorescent material in the TPTPA. The peak wavelengths and the shape of the electroluminescent (EL) spectra agree with those of the photoluminescent spectra, which indicate that the EL originates from the excited state of the TPTPA and dopant. The maximum luminance of approximately 11,000 and 2,000 cd/m2 were achieved for devices without and with dopant. While TPTPA device achieved good carrier balance, the hole current was decreased by doping a red phosphorescent material. Compared with the short response times of TPTPA device, relatively long response times of doped device was observed owing to phosphorescent recombination lifetime of a dopant. The TPTPA device exhibited the relatively high light outcoupling efficiency of approximately 34% (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of stimulants using gas chromatography/high‐resolution time‐of‐flight mass spectrometry and a soft ionization source
Authors: Lopez‐Avila Viorica , Cooley James , Urdahl Randall , Thevis Mario 
Published: October 2012

RATIONALEThe aim of this study was to investigate the mass spectral fragmentation of a small set of stimulants in a high‐resolution time‐of‐flight mass spectrometer equipped with a soft ionization source using vacuum ultraviolet (VUV) photons emitted from different plasma gases. It was postulated that the use of a plasma gas such as Xe, which emits photons at a lower energy than Kr or Ar, would lead to softer ionization of the test compounds, and thus to less fragmentation.METHODSA set of nine stimulants: cocaine, codeine, nicotine, methadone, phenmetrazine, pentylenetetrazole, niketamide, fencamfamine, and caffeine, was analyzed by gas chromatography/time‐of‐flight mass spectrometry (GC/TOFMS) in positive ion mode with this soft ionization source, using either Xe, Kr, or Ar as plasma gases. Working solutions of the test compounds at 0.1 to 100 ng/μL were used to establish instrument sensitivity and linearity.RESULTSAll test compounds, except methadone and pentylenetetrazole, exhibited strong molecular ions and no fragmentation with Xe‐microplasma photoionization (MPPI). Methadone exhibited significant fragmentation not only with Xe, but also with Kr and Ar, and pentylenetetrazole could not be ionized with Xe, probably because its ionization energy is above 8.44 eV. The Kr‐ and Ar‐MPPI mass spectra of the test compounds showed that the relative intensity of the molecular ion decreased as the photon energy increased.CONCLUSIONSWhen coupled to a TOF mass spectrometer this soft ionization source has demonstrated signal‐to‐noise (S/N) ratios from 7 to 730 at 100 pg per injection (depending on the compound), and a dynamic range of three orders of magnitude (100 pg to 100 ng) for some of the test compounds. Copyright © 2012 John Wiley & Sons, Ltd.
More inclusive or selective ionization for mass spectrometry using obstructive sonic spray ionization and voltage polarity switching
Authors: Chubatyi Nicholas D. , Wang Tongwen , McEwen Charles N. 
Published: October 2012

RATIONALEA new variation of sonicspray ionization (SSI) significantly enhances its sensitivity with an advantage of producing selective or more inclusive ionization by changing the polarity of the potential applied to an obstruction in the path of the SSI spray. This technique also provides high sensitivity with water solutions, which is difficult for electrospray ionization (ESI) without added organic solvent.METHODSAn Orbitrap Exactive mass spectrometer with an IonMax source heated electrospray ionization (ESI) probe operating at its maximum sheath gas setting was used for SSI. Both positive and negative polarities varying from 0.1 to 4 kV were applied to a metal obstruction positioned in the path of the spray using an atmospheric solid analysis probe. All mass spectra for this study were acquired in the positive ion mode.RESULTSSSI using a variety of obstructions improved the observed analyte ion abundance of small molecules, peptides, and proteins by approximately two orders of magnitude. The addition of a DC or AC voltage to a metal obstruction further enhanced the abundance of analyte ions by an additional two orders of magnitude. The relative abundances of the detected positive ions were considerably altered by switching the voltage polarity on the obstruction.CONCLUSIONSSSI with an obstruction improves the sensitivity of various samples compared with SSI. An applied voltage onto the obstruction further enhances the analyte ion abundances to approximately equal that of ESI but has the added advantage that switching the voltage polarity from positive to negative on the obstruction emphasizes different compounds present in the sample. Copyright © 2012 John Wiley & Sons, Ltd.
Comfort and Burden: The Changing Meaning of Home for Owners At‐Risk of Foreclosure
Authors: McCormack Karen 
Published: October 2012

AbstractThe home is a meaningful site of security, control, and comfort. On the basis of ethnographic data, this paper examines how the meaning of home changes for people at‐risk of foreclosure and how their subsequent actions are shaped by these meanings. I explore shifts in the meaning of home, with particular attention to the interaction of race, family structure, and immigrant status in these constructions. As owners respond to foreclosure threat, interactions with lenders further leave owners with a sense that the process is beyond their control, threatening ontological security and a sense of being at home in the world.
Variations in interpulse interval of double action potentials during propagation in single neurons
Authors: Villagran‐Vargas Edgar , Rodríguez‐Sosa Leonardo , Hustert Reinhold , Blicher Andreas , Laub Katrine , Heimburg Thomas 
Published: October 2012

AbstractIn this work, we analyzed the interpulse interval (IPI) of doublets and triplets in single neurons of three biological models. Pulse trains with two or three spikes originate from the process of sensory mechanotransduction in neurons of the locust femoral nerve, as well as through spontaneous activity both in the abdominal motor neurons and the caudal photoreceptor of the crayfish. We show that the IPI for successive low‐frequency single action potentials, as recorded with two electrodes at two different points along a nerve axon, remains constant. On the other hand, IPI in doublets either remains constant, increases or decreases by up to about 3 ms as the pair propagates. When IPI increases, the succeeding pulse travels at a slower speed than the preceding one. When IPI is reduced, the succeeding pulse travels faster than the preceding one and may exceed the normal value for the specific neuron. In both cases, IPI increase and reduction, the speed of the preceding pulse differs slightly from the normal value, therefore the two pulses travel at different speeds in the same nerve axon. On the basis of our results, we may state that the effect of attraction or repulsion in doublets suggests a tendency of the spikes to reach a stable configuration. We strongly suggest that the change in IPI during spike propagation of doublets opens up a whole new realm of possibilities for neural coding and may have major implications for understanding information processing in nervous systems. Synapse, 2013. © 2012 Wiley Periodicals, Inc.
State‐specific multireference coupled‐cluster theory
Authors: Köhn Andreas , Hanauer Matthias , Mück Leonie Anna , Jagau Thomas‐Christian , Gauss Jürgen 
Published: October 2012

AbstractThe multireference problem is considered one of the great challenges in coupled‐cluster (CC) theory. Most recent developments are based on state‐specific approaches, which focus on a single state and avoid some of the numerical problems of more general approaches. We review various state‐of‐the‐art methods, including Mukherjee's state‐specific multireference coupled‐cluster (Mk‐MRCC) theory, multireference Brillouin–Wigner coupled‐cluster (MR‐BWCC) theory, the MRexpT method, and internally contracted multireference coupled‐cluster (ic‐MRCC) theory. Related methods such as extended single‐reference schemes [e.g., the complete active space coupled‐cluster (CASCC) theory] and canonical transformation (CT) theory are covered as well. The comparison is done on the basis of formal arguments, implementation issues, and numerical results. Although a final and generally accepted multireference CC theory is still lacking, it is emphasized that recent developments render the new MRCC schemes useful tools for solving chemical problems. © 2012 John Wiley & Sons, Ltd.This article is categorized under:

Electronic Structure Theory > Ab Initio Electronic Structure Methods
Kidney organogenesis in the zebrafish: insights into vertebrate nephrogenesis and regeneration
Authors: Gerlach Gary F. , Wingert Rebecca A. 
Published: October 2012

AbstractVertebrates form a progressive series of up to three kidney organs during development—the pronephros, mesonephros, and metanephros. Each kidney derives from the intermediate mesoderm and is comprised of conserved excretory units called nephrons. The zebrafish is a powerful model for vertebrate developmental genetics, and recent studies have illustrated that zebrafish and mammals share numerous similarities in nephron composition and physiology. The zebrafish embryo forms an architecturally simple pronephros that has two nephrons, and these eventually become a scaffold onto which a mesonephros of several hundred nephrons is constructed during larval stages. In adult zebrafish, the mesonephros exhibits ongoing nephrogenesis, generating new nephrons from a local pool of renal progenitors during periods of growth or following kidney injury. The characteristics of the zebrafish pronephros and mesonephros make them genetically tractable kidney systems in which to study the functions of renal genes and address outstanding questions about the mechanisms of nephrogenesis. Here, we provide an overview of the formation and composition of these zebrafish kidney organs, and discuss how various zebrafish mutants, gene knockdowns, and transgenic models have created frameworks in which to further delineate nephrogenesis pathways. WIREs Dev Biol 2013, 2:559–585. doi: 10.1002/wdev.92This article is categorized under:

Gene Expression and Transcriptional Hierarchies > Regulatory Mechanisms
Vertebrate Organogenesis > From a Tubular Primordium: Non-Branched
Vertebrate Organogenesis > From a Tubular Primordium: Branched