bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rare disease centers for periodic paralysis: China versus the United States and United Kingdom
Authors: Ke Qing , Qi Ming , Wu Weiping , Luo Benyan , Hanna Michael , Herr Barbara , Griggs Robert C. ,   the Consortium for Investigation of Neurological Channelopathies (CINCH)
Published: July 2013

ABSTRACTIntroduction: We have developed a rare disease center in China. Methods: In this study we analyzed how patients with periodic paralysis accessed centers in China vs. in the USA and UK. Results: A total of 116 patients with periodic paralysis were evaluated in Beijing and Hangzhou (2003–2012). These patients traveled long distances for outpatient specialist care without an appointment or physician referral. In contrast, at the University of Rochester in the USA, >90% of patients were referred from physicians throughout the country by identifying physician expertise or by referrals from a patient advocacy group. In the UK, a single center, supported by the National Health Service, provides assessment/genetic testing for all UK patients. Conclusions: Rare disease centers in China require: (1) establishing a center for clinical characterization of the disease (e.g., periodic paralysis); (2) establishing a genetic diagnostic platform; (3) placing the center at a major city hospital; and (4) facilitating patient access through internet websites. Muscle Nerve 49: 171–174, 2014
Feature selection for motor unit potential train characterization
Authors: Abdelmaseeh Meena , Smith Benn , Stashuk Daniel 
Published: July 2013

ABSTRACTIntroduction: Ten new features of motor unit potential (MUP) morphology and stability are proposed. These new features, along with 8 traditional features, are grouped into 5 aspects: size, shape, global complexity, local complexity, and stability. Methods: We used sequential forward and backward search strategies to select subsets of these 18 features to discriminate accurately between muscles whose MUPs are predominantly neurogenic, myopathic, or normal. Results and Conclusions: Results based on 8102 motor unit potential trains (MUPTs) extracted from 4 different limb muscles (n = 336 total muscles) demonstrate the usefulness of these newly introduced features and support an aspect‐based grouping of MUPT features. Muscle Nerve 49: 680–690, 2014
Mirabegron: new treatment for OAB with fewer side‐effects
Authors: Chaplin Steve , Chapple Christopher 
Published: July 2013

AbstractMirabegron (Betmiga) is a new class of drug for the treatment of overactive bladder. In our New products review, Steve Chaplin presents the clinical data relating to its efficacy and adverse events, and Professor Chapple discusses its place in treatment compared with anticholinergics.
Investigation of carrier spill‐over in InGaN‐based light‐emitting diodes by temperature dependences of resonant photoluminescence and open‐circuit voltage
Authors: Han Dong‐Pyo , Kang Min‐Goo , Oh Chan‐Hyoung , Kim Hyunsung , Kim Kyu‐Sang , Shin Dong‐Soo , Shim Jong‐In 
Published: July 2013

AbstractIn InGaN‐based light‐emitting diodes (LEDs), carrier leakage to the outside of the active quantum wells (QWs) has been considered as one of the dominant carrier loss mechanisms at high current densities. In order to verify the carrier spill‐over phenomenon, we compared the electroluminescence (EL) efficiency, the resonant photoluminescence (PL) efficiency, and the open‐circuit voltage as functions of current, temperature, and excitation laser power. Very similar tendencies were experimentally observed among the three physical quantities, which implied that carriers were spilt over out of the QWs even in the resonant PL experiment.
Density functional theory study of the impact of tin doping on oxygen diffusion in Czochralski silicon
Authors: Gao Chao , Ma Xiangyang , Yang Deren 
Published: July 2013

AbstractThe impact of tin (Sn) doping on interstitial oxygen (Oi) diffusion in Czochralski silicon is investigated by density functional theory (DFT) calculations. Two aspects are taken into consideration: (i) Sn induced lattice strain and lattice expansion; (ii) direct and vacancy‐mediated interaction between Sn and Oi atoms. The calculations show that the interstitial oxygen migration energy barrier increases with increasing lattice constant which grows with the concentration of Sn. Structure analysis indicates that the geometric parameters such as the bond length and the angle of SiOSi configuration also increase with the lattice constant, which is considered to be the origin of the increased energy barrier for oxygen diffusion. SnO pair formation is found to be energetically unfavorable, while the SnVO complexes have a large binding energy. Sn is however able to trap Oi atoms by stimulating vacancy generation around it, which increases the oxygen diffusion energy barrier as well. It is thus predicted that oxygen diffusion in silicon with a high concentration of Sn atoms will be retarded.
Efficiency enhancement of Cu(In,Ga)Se2 thin‐film solar cells by a post‐deposition treatment with potassium fluoride
Authors: Laemmle Anke , Wuerz Roland , Powalla Michael 
Published: July 2013

AbstractAlkali‐free Cu(In,Ga)Se2(CIGS) absorbers grown on Mo‐coated alumina (Al2O3) substrates were doped with potassium (K) after CIGS growth by a potassium fluoride (KF) post‐deposition treatment (PDT). The addition of K to the absorber leads to a strong increase in cell efficiency from 10.0% for the K‐free cell to 14.2% for the K‐doped cell, mainly driven by an increase in the open‐circuit voltage Voc and the fill factor FF, and to an increase in the net charge carrier density. Hence K doping by KF‐PDT is comparable to doping with Na.magnified imageJ –V characteristics of a CIGS solar cell with KF‐PDT (red solid line) and of a K‐free reference cell without treatment (black dashed line). The solar cell treated with K shows a strong increase in Voc and FF compared to the solar cell without K.(© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Unusual domain configurations and local piezoresponse in the [720]‐cut BaTiO3 single crystal
Authors: Zeng H. R. , Sun F. , Zhao K. Y. , Li F. X. , Zhang X. W. , Chu R. Q. , Luo H. S. , Li G. R. 
Published: July 2013

AbstractThe domain configurations and local piezoresponse property of the [720]‐cut BaTiO3 single crystal and [001]‐oriented BaTiO3 crystal were investigated by high‐resolution piezoresponse force microscopy. Large differences in their surface topography features, domain configurations and local piezoresponse were found between [720]‐cut and [001]‐oriented BaTiO3 crystals. The large surface bending angle due to ferroelastic domain walls leads to a high strain energy appearing in the [720]‐cut BaTiO3, further resulting in unique band‐like topographic features, needle domains for stress compensation and locally ultrahigh piezoelectric response as well. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Four‐dimensional tensor equations for a classical fluid in an external gravitational field
Authors: Charron Martin , Zadra Ayrton , Girard Claude 
Published: July 2013

AbstractA four‐dimensional tensor formalism suitable for the equations of motion of a classical fluid in the presence of a given external gravitational field is presented. The formalism allows for arbitrary time‐dependent transformations of spatial coordinates. Some well‐known conservation laws are derived in covariant form. The metric tensor and the associated Christoffel symbols are calculated for coordinate systems useful in meteorology. The vertical momentum equation employed in the Canadian operational weather forecasting model is obtained using the proposed tensor formalism.
Hydrogen isotope ratio mass spectrometry and high‐resolution/high‐accuracy mass spectrometry in metabolite identification studies: Detecting target compounds for sports drug testing
Authors: Thevis Mario , Piper Thomas , Horning Stevan , Juchelka Dieter , Schänzer Wilhelm 
Published: July 2013

RATIONALEIn sports drug testing, comprehensive studies on the metabolism of therapeutic agents with misuse potential are necessary to identify metabolites that provide utmost retrospectivity and specificity. By commonly employed approaches minor and/or long‐term metabolites in urine might remain undetected. Hence, an alternative strategy to unambiguously identify the majority of urinary metabolites including low‐abundance representatives is desirable.METHODSUrine samples were collected for 20 days during an elimination study with an oral dose of 5 mg of 17α‐C2H3‐metandienone. The specimens were processed according to established sample preparation procedures (including fractionation and deconjugation) and subjected to gas chromatography/hydrogen isotope ratio mass spectrometry (GC/IRMS) analysis. Due to the deuteration of the administered drug, urinary metabolites bearing the deuterium label yield abundant and specific signals on the GC/IRMS instrument resulting from the substantially altered 2H/1H ratio. The sample aliquots were measured by gas chromatography/time‐of‐flight (GC/Q‐TOF) mass spectrometry using identical GC conditions, allowing high‐resolution/high‐accuracy mass data to be obtained on all urinary metabolites previously identified by IRMS.RESULTSWithin the IRMS chromatograms, labeled metabolites were identified up to 20 days after administration at urinary concentration down to 0.25 ng/mL. More than 50 metabolites were observed with the earlier described long‐term metabolite of metandienone, 18‐nor‐17β‐hyroxymethyl,17α‐methyl‐androst‐1,4,13‐trien‐3‐one, being the most prominent glucuronidated metabolite in the studied time window. In the sulfoconjugated steroids fraction, a yet unknown metabolite was observed at m/z 283.1997 comprising the experimentally determined elemental composition of C20H212H3O.CONCLUSIONSCombining IRMS with high‐resolution mass spectrometry considerably facilitates and accelerates metabolite identification of deuterium‐labeled compounds in urine. Of particular relevance in doping control, the principle is applicable also to other arenas of drug research, allowing the preparation and administration of e.g. radioactively labeled substances to be omitted. © 2013 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd.
Ionospheric observations of underground nuclear explosions (UNE) using GPS and the Very Large Array
Authors: Park Jihye , Helmboldt Joseph , Grejner‐Brzezinska Dorota A. , von Frese Ralph R. B. , Wilson Thomas L. 
Published: July 2013

AbstractObservations from Global Positioning System (GPS) receivers and the Very Large Array (VLA) radio telescope recorded traveling ionospheric disturbances (TID) from underground nuclear explosions (UNEs), detonated in September 1992. The slant TEC (STEC) data derived from GPS observations were processed for all ray paths to isolate TIDs. For the TIDs from the Hunters Trophy test on 18 September 1992 and the Divider test on 23 September 1992, the propagated mean velocities of the TIDs were about 573 m/s and 740 m/s with standard deviations of 85 m/s and 135 m/s, respectively. For the VLA observations, the spectral analysis produced three‐dimensional fluctuation spectral cubes for the Hunters Trophy event. The arrival time of the TID at the VLA implied a propagation speed of 570–710 m/s. This study suggests the global availability of GNSS tracking networks and new low‐frequency (VHF) radio telescopes may offer a method of UNE detection and characterization, which could complement the International Monitoring System (IMS).
Enrichment of human embryonic stem cell-derived NKX6.1-expressing pancreatic progenitor cells accelerates the maturation of insulin-secreting cells in vivo
Authors: Rezania Alireza , Bruin Jennifer E. , Xu Jean , Narayan Kavitha , Fox Jessica K. , O'Neil John J. , Kieffer Timothy J. 
Published: July 2013

Abstract
Human embryonic stem cells (hESCs) are considered a potential alternative to cadaveric islets as a source of transplantable cells for treating patients with diabetes. We previously described a differentiation protocol to generate pancreatic progenitor cells from hESCs, composed of mainly pancreatic endoderm (PDX1/NKX6.1-positive), endocrine precursors (NKX2.2/synaptophysin-positive, hormone/NKX6.1-negative), and polyhormonal cells (insulin/glucagon-positive, NKX6.1-negative). However, the relative contributions of NKX6.1-negative versus NKX6.1-positive cell fractions to the maturation of functional β-cells remained unclear. To address this question, we generated two distinct pancreatic progenitor cell populations using modified differentiation protocols. Prior to transplant, both populations contained a high proportion of PDX1-expressing cells (∼85%–90%) but were distinguished by their relatively high (∼80%) or low (∼25%) expression of NKX6.1. NKX6.1-high and NKX6.1-low progenitor populations were transplanted subcutaneously within macroencapsulation devices into diabetic mice. Mice transplanted with NKX6.1-low cells remained hyperglycemic throughout the 5-month post-transplant period whereas diabetes was reversed in NKX6.1-high recipients within 3 months. Fasting human C-peptide levels were similar between groups throughout the study, but only NKX6.1-high grafts displayed robust meal-, glucose- and arginine-responsive insulin secretion as early as 3 months post-transplant. NKX6.1-low recipients displayed elevated fasting glucagon levels. Theracyte devices from both groups contained almost exclusively pancreatic endocrine tissue, but NKX6.1-high grafts contained a greater proportion of insulin-positive and somatostatin-positive cells, whereas NKX6.1-low grafts contained mainly glucagon-expressing cells. Insulin-positive cells in NKX6.1-high, but not NKX6.1-low grafts expressed nuclear MAFA. Collectively, this study demonstrates that a pancreatic endoderm-enriched population can mature into highly functional β-cells with only a minor contribution from the endocrine subpopulation.
In situ mechanotransduction via vinculin regulates stem cell differentiation
Authors: Holle Andrew W. , Tang Xinyi , Vijayraghavan Deepthi , Vincent Ludovic G. , Fuhrmann Alexander , Choi Yu Suk , Álamo Juan C. , Engler Adam J. 
Published: July 2013

Abstract
Human mesenchymal stem cell (hMSC) proliferation, migration, and differentiation have all been linked to extracellular matrix stiffness, yet the signaling pathway(s) that are necessary for mechanotransduction remain unproven. Vinculin has been implicated as a mechanosensor in vitro, but here we demonstrate its ability to also regulate stem cell behavior, including hMSC differentiation. RNA interference-mediated vinculin knockdown significantly decreased stiffness-induced MyoD, a muscle transcription factor, but not Runx2, an osteoblast transcription factor, and impaired stiffness-mediated migration. A kinase binding accessibility screen predicted a cryptic MAPK1 signaling site in vinculin which could regulate these behaviors. Indeed, reintroduction of vinculin domains into knocked down cells indicated that MAPK1 binding site-containing vinculin constructs were necessary for hMSC expression of MyoD. Vinculin knockdown does not appear to interfere with focal adhesion assembly, significantly alter adhesive properties, or diminish cell traction force generation, indicating that its knockdown only adversely affected MAPK1 signaling. These data provide some of the first evidence that a force-sensitive adhesion protein can regulate stem cell fate.
Performance limitations for nanowire/nanoribbon biosensors
Authors: Rajan Nitin K. , Duan Xuexin , Reed Mark A. 
Published: July 2013

Field‐effect transistor‐based biosensors (bioFETs) have shown great promise in the field of fast, ultra‐sensitive, label‐free detection of biomolecules. Reliability and accuracy, when trying to measure small concentrations, is of paramount importance for the translation of these research devices into the clinical setting. Our knowledge and experience with these sensors has reached a stage where we are able to identify three main aspects of bioFET sensing that currently limit their applications. By considering the intrinsic device noise as a limitation to the smallest measurable signal, we show how various parameters, processing steps and surface modifications, affect the limit of detection. We also introduce the signal‐to‐noise ratio of bioFETs as a universal performance metric, which allows us to gain better insight into the design of more sensitive devices. Another aspect that places a limit on the performance of bioFETs is screening by the electrolyte environment, which reduces the signal that could be potentially measured. Alternative functionalization and detection schemes that could enable the use of these charge‐based sensors in physiological conditions are highlighted. Finally, the binding kinetics of the receptor–analyte system are considered, both in the context of extracting information about molecular interactions using the bioFET sensor platform and as a fundamental limitation to the number of molecules that bind to the sensor surface at steady‐state conditions and to the signal that is generated. Some strategies to overcome these limitations are also proposed. Taken together, these performance‐limiting issues, if solved, would bring bioFET sensors closer to clinical applications. WIREs Nanomed Nanobiotechnol 2013, 5:629–645. doi: 10.1002/wnan.1227This article is categorized under:

Diagnostic Tools > Biosensing
Diagnostic Tools > Diagnostic Nanodevices
Reprogramming cells and tissue patterning via bioelectrical pathways: molecular mechanisms and biomedical opportunities
Authors: Levin Michael 
Published: July 2013

Transformative impact in regenerative medicine requires more than the reprogramming of individual cells: advances in repair strategies for birth defects or injuries, tumor normalization, and the construction of bioengineered organs and tissues all require the ability to control large‐scale anatomical shape. Much recent work has focused on the transcriptional and biochemical regulation of cell behavior and morphogenesis. However, exciting new data reveal that bioelectrical properties of cells and their microenvironment exert a profound influence on cell differentiation, proliferation, and migration. Ion channels and pumps expressed in all cells, not just excitable nerve and muscle, establish resting potentials that vary across tissues and change with significant developmental events. Most importantly, the spatiotemporal gradients of these endogenous transmembrane voltage potentials (Vmem) serve as instructive patterning cues for large‐scale anatomy, providing organ identity, positional information, and prepattern template cues for morphogenesis. New genetic and pharmacological techniques for molecular modulation of bioelectric gradients in vivo have revealed the ability to initiate complex organogenesis, change tissue identity, and trigger regeneration of whole vertebrate appendages. A large segment of the spatial information processing that orchestrates individual cells' programs toward the anatomical needs of the host organism is electrical; this blurs the line between memory and decision‐making in neural networks and morphogenesis in nonneural tissues. Advances in cracking this bioelectric code will enable the rational reprogramming of shape in whole tissues and organs, revolutionizing regenerative medicine, developmental biology, and synthetic bioengineering. WIREs Syst Biol Med 2013, 5:657–676. doi: 10.1002/wsbm.1236This article is categorized under:

Developmental Biology > Developmental Processes in Health and Disease
Laboratory Methods and Technologies > Imaging
Developmental Biology > Stem Cell Biology and Regeneration
A hybrid stochastic Galerkin method for uncertainty quantification applied to a conservation law modelling a clarifier‐thickener unit
Authors: Bürger R. , Kröker I. , Rohde C. 
Published: July 2013

AbstractThe continuous sedimentation process in a clarifier‐thickener can be described by a scalar nonlinear conservation law for the local solids volume fraction. The flux density function is discontinuous with respect to spatial position due to feed and discharge mechanisms. Typically, the feed flow cannot be given deterministically and efficient numerical simulation requires a concept for quantifying uncertainty. In this paper uncertainty quantification is expressed by a new hybrid stochastic Galerkin (HSG) method that extends the classical polynomial chaos approximation by multiresolution discretization in the stochastic space. The new approach leads to a deterministic hyperbolic system for a finite number of stochastic moments which is however partially decoupled and thus allows efficient parallelisation. The complexity of the problem is further reduced by stochastic adaptivity. For the approximate solution of the resulting high‐dimensional system a finite volume scheme is introduced. Numerical experiments cover one‐ and two‐dimensional situations.
A microscale second gradient approximation of the damage parameter of quasi‐brittle heterogeneous lattices
Authors: Rinaldi A. , Placidi L. 
Published: July 2013

AbstractLattice models are powerful tools to investigate damage processes in quasi‐brittle material by a microscale perspective. Starting from prior work on a novel rational damage theory for a 2D heterogenous lattice, this paper explores the connection between the series of critical strains at which the microcracks form (i.e. lattice links fail) and the second gradient of the microscale displacement field. Taking a simple tensile test as a representative case study for this endeavour, the analysis of accurate numerical results provides evidence that the second gradient of the microscale displacement field (notably the quantity | ∇ (∂ ux/∂ x)| for the specific example elaborated here) conveys indeed crucial information about the microcracks formation process and can be conveniently used to introduce simplifications of the rational theory that are of relevance by practical purposes as full field strain measurements become routinely possible with digital imaging correlation techniques. Note worthy, the results support the new view that the damage evolution is a three regimes process (I dilute damage, II homogeneous interaction, III localization.) The featured connection with the second gradient of the microscale displacement field is applicable in regions II–III, where microcracks interactions grow stronger and the lattice transitions to the softening regime. The potential impact of these findings towards the formulation of new and physically based CDM models, which are consistent with the reference discrete microscale theory, cannot be overlooked and is pointed out.
Harmonic vibrations of nanosized piezoelectric bodies with surface effects
Authors: Nasedkin A.V. , Eremeyev V.A. 
Published: July 2013

AbstractWe consider the harmonic and eigenvalue problems for piezoelectric nanodimensional bodies with account for surface stresses and surface electric charges. For harmonic problem new mathematical model is suggested, which generalizes the model of the piezoelectric medium with damping properties, boundary conditions of contact type and surface effects. The classical and generalized (weak) statements for harmonic and eigenvalue problems are formulated in the extended and reduced forms. The spectral properties of the eigenvalue problems with account for surface effects are determined. A variational minimal principle is constructed which is similar to the well‐known variational principle for problems for pure elastic and piezoelectric media. The discreteness of the spectrum and completeness of the eigenvectors are proved. As a consequence of variational principle, the properties of the natural frequencies increase or decrease are established for changing the mechanical, electric and “surface” boundary conditions and the moduli of piezoelectric body. The finite element approaches are described for determination of the natural frequencies, the resonance and antiresonance frequencies and harmonic behavior of nanosized piezoelectric bodies with account for surface effects.