bluuebunny/crossref_metadata_2025_split huggingface dataset:
Boron nitride nanotube‐enhanced osteogenic differentiation of mesenchymal stem cells
Authors: Li Xia , Wang Xiupeng , Jiang Xiangfen , Yamaguchi Maho , Ito Atsuo , Bando Yoshio , Golberg Dmitri 
Published: March 2015

AbstractThe interaction between boron nitride nanotubes (BNNTs) layer and mesenchymal stem cells (MSCs) is evaluated for the first time in this study. BNNTs layer supports the attachment and growth of MSCs and exhibits good biocompatibility with MSCs. BNNTs show high protein adsorption ability, promote the proliferation of MSCs and increase the secretion of total protein by MSCs. Especially, BNNTs enhance the alkaline phosphatase (ALP) activity as an early marker of osteoblasts, ALP/total protein and osteocalcin (OCN) as a late marker of osteogenic differentiation, which shows that BNNTs can enhance osteogenesis of MSCs. The release of trace boron and the stress on cells exerted by BNNTs with a fiber structure may account for the enhanced differentiation of MSCs into osteoblasts. Therefore BNNTs are potentially useful for bone regeneration in orthopedic applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 323–329, 2016.
Mst2 Controls Bone Homeostasis by Regulating Osteoclast and Osteoblast Differentiation
Authors: Lee Jongwon , Youn Bang Ung , Kim Kabsun , Kim Jung Ha , Lee Da-Hye , Seong Semun , Kim Inyoung , Han Seung-Hee , Che Xiangguo , Choi Je-Yong , Park Yong-Wook , Kook Hyun , Kim Kyung Keun , Lim Dae-Sik , Kim Nacksung 
Published: March 2015

ABSTRACT

Mammalian sterile 20-like kinase 2 (Mst2) plays a central role in the Hippo pathway, controlling cell proliferation, differentiation, and apoptosis during development. However, the roles of Mst2 in osteoclast and osteoblast development are largely unknown. Here, we demonstrate that mice deficient in Mst2 exhibit osteoporotic phenotypes with increased numbers of osteoclasts and decreased numbers of osteoblasts as shown by micro–computed tomography (µCT) and histomorphometric analyses. Osteoclast precursors lacking Mst2 exhibit increased osteoclastogenesis and Nfatc1, Acp5, and Oscar expression in response to receptor activator of NF-κB ligand (RANKL) exposure. Conversely, Mst2 overexpression in osteoclast precursors leads to the inhibition of RANKL-induced osteoclast differentiation. Osteoblast precursors deficient in Mst2 exhibit attenuated osteoblast differentiation and function by downregulating the expression of Runx2, Alpl, Ibsp, and Bglap. Conversely, ectopic expression of Mst2 in osteoblast precursors increases osteoblastogenesis. Finally, we demonstrate that the NF-κB pathway is activated by Mst2 deficiency during osteoclast and osteoblast development. Our findings suggest that Mst2 is involved in bone homeostasis, functioning as a reciprocal regulator of osteoclast and osteoblast differentiation through the NF-κB pathway. © 2015 American Society for Bone and Mineral Research.
SOXC Transcription Factors Induce Cartilage Growth Plate Formation in Mouse Embryos by Promoting Noncanonical WNT Signaling
Authors: Kato Kenji , Bhattaram Pallavi , Penzo-Méndez Alfredo , Gadi Abhilash , Lefebvre Véronique 
Published: March 2015

ABSTRACT

Growth plates are specialized cartilage structures that ensure the elongation of most skeletal primordia during vertebrate development. They are made by chondrocytes that proliferate in longitudinal columns and then progress in a staggered manner towards prehypertrophic, hypertrophic and terminal maturation. Complex molecular networks control the formation and activity of growth plates, but remain incompletely understood. We investigated here the importance of the SoxC genes, which encode the SOX4, SOX11 and SOX12 transcription factors, in growth plates. We show that the three genes are expressed robustly in perichondrocytes and weakly in growth plate chondrocytes. SoxCPrx1Cre mice, which deleted SoxC genes in limb bud skeletogenic mesenchyme, were born with tiny appendicular cartilage primordia because of failure to form growth plates. In contrast, SoxCCol2Cre and SoxCATC mice, which deleted SoxC genes primarily in chondrocytes, were born with mild dwarfism and fair growth plates. Chondrocytes in the latter mutants matured normally, but formed irregular columns, proliferated slowly and died ectopically. Asymmetric distribution of VANGL2 was defective in both SoxCPrx1Cre and SoxCATC chondrocytes, indicating impairment of planar cell polarity, a noncanonical WNT signaling pathway that controls growth plate chondrocyte alignment, proliferation and survival. Accordingly, SoxC genes were necessary in perichondrocytes for expression of Wnt5a, which encodes a noncanonical WNT ligand required for growth plate formation, and in chondrocytes and perichondrocytes for expression of Fzd3 and Csnk1e, which encode a WNT receptor and casein kinase-1 subunit mediating planar cell polarity, respectively. Reflecting the differential strengths of the SOXC protein transactivation domains, SOX11 was more powerful than SOX4, and SOX12 interfered with the activity of SOX4 and SOX11. Altogether, these findings provide novel insights into the molecular regulation of skeletal growth by proposing that SOXC proteins act cell- and non-cell-autonomously in perichondrocytes and chondrocytes to establish noncanonical WNT signaling crosstalk essential for growth plate induction and control. © 2015 American Society for Bone and Mineral Research.
Zinc-Induced Effects on Osteoclastogenesis Involves Activation of Hyperpolarization-Activated Cyclic Nucleotide Modulated Channels via Changes in Membrane Potential
Authors: Notomi Takuya , Kuno Miyuki , Hiyama Akiko , Ohura Kiyoshi , Noda Masaki , Skerry Timothy M 
Published: March 2015

ABSTRACT

Zinc is a trace element in the mammalian body, and increasing evidence shows its critical role in bone development and osteoclastogenesis. The relationships between zinc and voltage-gated ion channels have been reported; however, the effects of zinc on membrane potential and the related ion channels remain unknown. In this study, we found that zinc-induced hyperpolarization in RAW264.7 cells (RAW) was promoted by inhibition of hyperpolarization-activated cyclic nucleotide modulated channels (HCNs). In electrophysiological experiments with RAW-derived osteoclasts, HCNs were functional and generated hyperpolarization-activated inward currents (Ih) with properties similar to the Ih recorded in excitable cells such as neurons and cardiomyocytes. Quantitative PCR of HCN subunits HCN1 and HCN4 in RAW cells showed detectable levels of HCN1 mRNA and HCN4 expression was the highest of all four subunits. HCN4 knockdown decreased osteoclastic Ih and promoted osteoclastogenesis in the presence of zinc, but not in the absence of zinc. To determine the effect of membrane hyperpolarization on osteoclastogenesis, we developed a light-controllable membrane potential system in RAW cells by stably expressing the light-driven outward proton pump, Archaerhodopsin3 (Arch). Arch activation by yellow-green light hyperpolarizes the cell membrane. Light-induced hyperpolarization accelerated osteoclast differentiation in the presence of receptor activator of nuclear factor kappa-B ligand (RANKL). Thus, HCN activation reduced the hyperpolarization-related promotion of osteoclast differentiation in the presence of zinc. This study revealed the novel role of HCN and membrane potential in non-excitable osteoclasts. © 2015 American Society for Bone and Mineral Research.
STAQ: A route toward low power, Multicolor nanoscopy
Authors: Rosales Tilman , Sackett Dan L. , Xu Jianhua , Shi Zhen‐Dan , Xu Biying , Li Haitao , Kaur Gurpreet , Frohart Erin , Shenoy Nalini , Cheal Sarah M. , Wu Haitao , Dulcey Andrés E. , Hu Yulin , Li Changhui , Lane Kelly , Griffiths Gary L. , Knutson Jay R. 
Published: March 2015

ABSTRACTNanoscopy has now become a real procedure in fluorescence microscopy of living cells. The STED/RESOLFT family of nanoscopy approaches has the best prospects for delivering high speed imaging, but the history of STED includes a continuing struggle to reduce the deactivation power applied, along with difficulties in achieving simultaneous multicolor images. In this manuscript, we present a concept for a similar real‐time nanoscopy, using a new class of bipartite probes that separate the luminescent and quenching functions into two coupled molecules. In particular, the STAQ (Superresolution via Transiently Activated Quencher) example we show herein employs the excited state absorbance (not ground state) of the partner to accept energy from and quench the luminescent dye. The result is that much less deactivation power is needed for superresolved (∼50 nm) imaging. Moreover, the TAQ partner excited by the “donut” beam is shown to quench several different visible dyes via the same mechanism, opening the door to easier multicolor imaging. We demonstrate three dyes sharing the same deactivation and show examples of superresolved multicolor images. We suggest STAQ will facilitate the growth of real‐time nanoscopy by reducing confounding photodamage within living cells while expanding the nanoscopist's palette. Microsc. Res. Tech. 78:343–355, 2015. Published 2015. This article is a U.S. Government work and is in the public domain in the USA
Shape Memory Hydrogel based on a Hydrophobically‐Modified Polyacrylamide (HMPAM)/α‐CD Mixture via a Host‐Guest Approach
Authors: Yasin Akram , Zhou Wanfu , Yang Haiyang , Li Huazhen , Chen Yin , Zhang Xingyuan 
Published: March 2015

A novel thermally sensitive shape memory (SM) hydrogel is prepared by block copoly­merization of a cationic surfactant monomer, dimethylhexadecyl[2‐(dimethylamino)ethylmethacrylate]ammoniumbromide (C16DMAEMA), and acrylamide (AM) in the presence of α‐cyclodextrin (α‐CD) using N,N’‐methylenebisacrylamide (MBA) as a crosslinker. XRD, solid state 13C NMR, and DSC measurements show that the crystalline domains, induced by the hydrogen bonds between α‐CDs threaded on the hydrophobic units of the polymer chains through the host‐guest approach, can reversibly melt and crystallize at different temperatures. Rheological measurements show that both the elastic modulus G’ and viscous modulus G’’ drastically change due to the formation and dissolution of the crystalline domains. These thermo‐sensitive crystalline domains serve as reversible physical crosslinks, endowing the hydrogel with excellent SM properties. Cyclic experiments show that the hydrogel can recover to almost 100% of the deformation in each cycle and can be reused several times.
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3D high‐resolution diffusion‐weighted MRI at 3T: Preliminary application in prostate cancer patients undergoing active surveillance protocol for low‐risk prostate cancer
Authors: Nguyen Christopher , Sharif‐Afshar Ali‐Reza , Fan Zhaoyang , Xie Yibin , Wilson Sidney , Bi Xiaoming , Payor Lucas , Saouaf Rola , Kim Hyung , Li Debiao 
Published: March 2015

PurposeTo improve spatial resolution and image quality of diffusion‐weighted (DW) MRI in detecting low‐risk prostate cancer (lrPC) in patients undergoing active surveillance protocol (AS‐PC), we propose the application of a diffusion‐prepared balanced steady‐state free precession (bSSFP) technique capable of multishot acquisition.MethodsDiffusion‐prepared bSSFP was compared with single‐shot DW echo planar imaging (SS‐DW‐EPI) at two prescribed resolutions (2.1 × 2.1 × 3.5mm3, 0.9 × 0.9 × 3.5 mm3) in nine healthy subjects and nine AS‐PC patients. Geometric distortion and susceptibility artifacts were quantitatively assessed in all subjects. In AS‐PC patients, lesion detection via blinded multiparametric MRI including T1‐weighted, T2‐weighted, dynamic contrast‐enhanced imaging, and along with either of two DW methods were evaluated against 12‐point biopsy.ResultsGeometric distortion and susceptibility artifacts were significantly less for diffusion‐prepared bSSFP at both prescribed spatial resolutions than SS‐DW‐EPI. Apparent diffusion coefficients of healthy prostate tissue were concordant between the two DW methods at both spatial resolutions. In AS‐PC patients, multiparametric MRI with diffusion‐prepared bSSFP had greater sensitivity (94%, 63%), accuracy (76%, 67%), positive‐predictive value (54%, 48%), negative‐predictive value (97%, 82%), and area under the curve (0.80, 0.67) than with SS‐DW‐EPI.ConclusionsThe proposed diffusion‐prepared technique with higher spatial resolution and improved image quality over SS‐DW‐EPI resulted in better multiparametric MRI detection of lrPC in AS‐PC patients. Magn Reson Med 75:616–626, 2016. © 2015 Wiley Periodicals, Inc.
Analytical three‐point Dixon method: With applications for spiral water–fat imaging
Authors: Wang Dinghui , Zwart Nicholas R. , Li Zhiqiang , Schär Michael , Pipe James G. 
Published: March 2015

PurposeThe goal of this work is to present a new three‐point analytical approach with flexible even or uneven echo increments for water–fat separation and to evaluate its feasibility with spiral imaging.Theory and MethodsTwo sets of possible solutions of water and fat are first found analytically. Then, two field maps of the B0 inhomogeneity are obtained by linear regression. The initial identification of the true solution is facilitated by the root‐mean‐square error of the linear regression and the incorporation of a fat spectrum model. The resolved field map after a region‐growing algorithm is refined iteratively for spiral imaging. The final water and fat images are recalculated using a joint water–fat separation and deblurring algorithm.ResultsSuccessful implementations were demonstrated with three‐dimensional gradient‐echo head imaging and single breathhold abdominal imaging. Spiral, high‐resolution T1‐weighted brain images were shown with comparable sharpness to the reference Cartesian images.ConclusionWith appropriate choices of uneven echo increments, it is feasible to resolve the aliasing of the field map voxel‐wise. High‐quality water–fat spiral imaging can be achieved with the proposed approach. Magn Reson Med 75:627–638, 2016. © 2015 Wiley Periodicals, Inc.
Removal of nuisance signals from limited and sparse 1H MRSI data using a union‐of‐subspaces model
Authors: Ma Chao , Lam Fan , Johnson Curtis L. , Liang Zhi‐Pei 
Published: March 2015

PurposeTo remove nuisance signals (e.g., water and lipid signals) for 1H MRSI data collected from the brain with limited and/or sparse (k, t)‐space coverage.MethodsA union‐of‐subspace model is proposed for removing nuisance signals. The model exploits the partial separability of both the nuisance signals and the metabolite signal, and decomposes an MRSI dataset into several sets of generalized voxels that share the same spectral distributions. This model enables the estimation of the nuisance signals from an MRSI dataset that has limited and/or sparse (k, t)‐space coverage.ResultsThe proposed method has been evaluated using in vivo MRSI data. For conventional chemical shift imaging data with limited k‐space coverage, the proposed method produced “lipid‐free” spectra without lipid suppression during data acquisition at 130 ms echo time. For sparse (k, t)‐space data acquired with conventional pulses for water and lipid suppression, the proposed method was also able to remove the remaining water and lipid signals with negligible residuals.ConclusionNuisance signals in 1H MRSI data reside in low‐dimensional subspaces. This property can be utilized for estimation and removal of nuisance signals from 1H MRSI data even when they have limited and/or sparse coverage of (k, t)‐space. The proposed method should prove useful especially for accelerated high‐resolution 1H MRSI of the brain. Magn Reson Med, 2015. © 2015 Wiley Periodicals, Inc. Magn Reson Med 75:488–497, 2016. © 2015 Wiley Periodicals, Inc.
Reproducibility of phase rotation stimulated echo acquisition mode at 3T in schizophrenia: Emphasis on glutamine
Authors: Bustillo Juan R. , Rediske Nathan , Jones Thomas , Rowland Laura M. , Abbott Christopher , Wijtenburg S. Andrea 
Published: March 2015

PurposeTo determine the reproducibility and reliability of glutamine (Gln), measured with a very short echo time phase rotation stimulated echo acquisition mode (VTE‐PR STEAM) sequence at 3T, in subjects with schizophrenia.MethodsSeven subjects with schizophrenia were scanned twice with VTE‐PR STEAM in a Siemens 3T TIM Trio scanner with a 32‐channel head coil. Spectroscopic data were collected from two voxels in gray matter, one in the dorsal anterior cingulate and the other in the medial occipital cortex. Reproducibility was assessed using coefficients of variation (CVs) and reliability with standard error of measurement and intraclass correlations (ICCs). Phantoms containing increasing concentrations of Gln in a physiologic solution of other neurometabolites with overlapping resonances were scanned to assess the validity of spectral Gln measurement.ResultsVery good reliability and reproducibility for Gln in both regions of interest were supported by CVs of ≤10.0% and ICCs of ≥0.6, respectively. Phantom studies documented a robust correspondence between known Gln concentrations and VTE‐PR STEAM measurements of this metabolite (R2 = 0.988).ConclusionThe VTE‐PR STEAM approach at 3T permits the longitudinal assessment of Gln and other 1H MR spectroscopy neurometabolites in a clinically plausible setting. Magn Reson Med 75:498–502, 2016. © 2015 Wiley Periodicals, Inc.
Clinical utility of fetal autopsy and its impact on genetic counseling
Authors: Nayak Shalini S. , Shukla Anju , Lewis Leslie , Kadavigere Rajagopal , Mathew Mary , Adiga Prashanth K. , Vasudeva Akhila , Kumar Pratap , Shetty Jyothi , Shah Hitesh , Girisha Katta M. 
Published: March 2015

AbstractObjectivesWe aimed to analyze the utility of fetal autopsy in terms of its contribution to establishing a definitive diagnosis and its impact on genetic counseling.Subjects and methodsDetailed fetal autopsy was carried out in fetuses referred for examination. Clinical utility of fetal autopsy and its impact on counseling were measured by adapting previously published parameters.ResultsWe performed autopsy in 230 fetuses. There were 106 cases with single system and 92 cases with multisystem involvement. We confirmed prenatal findings in 23% of cases and observed additional findings in 37% of cases. In 23% of cases, autopsy findings differed enough to change the diagnosis. However, in 17% of fetuses, no cause of fetal loss was determined. Risk of recurrence became clear in 30.3% of the fetuses, and risk remained the same, but the diagnosis was different in 4.8% of cases after autopsy. Hence, autopsy led to refinement of the risk of recurrence in 36% of cases. Autopsy aided prenatal counseling of couples in 77% of cases by either confirming the prenatal findings (35%) or providing new information/ruling out a diagnosis (42%).ConclusionThe present study quantifies the utility of fetal autopsy in reproductive genetic counseling in a large cohort. © 2015 John Wiley & Sons, Ltd.
Investigation of the conformational dynamics of the apo A2A adenosine receptor
Authors: Caliman Alisha D. , Swift Sara E. , Wang Yi , Miao Yinglong , McCammon J. Andrew 
Published: March 2015

AbstractThe activation/deactivation processes for G‐protein coupled receptors (GPCRs) have been computationally studied for several different classes, including rhodopsin, the β2 adrenergic receptor, and the M2 muscarinic receptor. Despite determined cocrystal structures of the adenosine A2A receptor (A2AAR) in complex with antagonists, agonists and an antibody, the deactivation process of this GPCR is not completely understood. In this study, we investigate the convergence of two apo simulations, one starting with an agonist‐bound conformation (PDB: 3QAK)14 and the other starting with an antagonist‐bound conformation (PDB: 3EML)11. Despite the two simulations not completely converging, we were able to identify distinct intermediate steps of the deactivation process characterized by the movement of Y2887.53 in the NPxxY motif. We find that Y2887.53 contributes to the process by forming hydrogen bonds to residues in transmembrane helices 2 and 7 and losing these interactions upon full deactivation. Y1975.58 also plays a role in the process by forming a hydrogen bond only once the side chain moves from the lipid interface to the middle of the helical bundle.
Discrete breathers in 2D and 3D crystals
Authors: Dmitriev Sergey V. , Chetverikov Alexander P. , Velarde Manuel G. 
Published: March 2015

Discrete breathers (DB) are spatially localized, large‐amplitude vibrational modes in defect‐free nonlinear lattices. Recent numerical and experimental studies have confirmed that DB exist in crystals. In the present work, we briefly describe the well‐known existence conditions of DB in crystals and present our recent results on DB in 2D crystals such as graphene and graphane and in 3D crystals such as alkali halide crystals and pure metals. The possible role of DB in solid state physics and materials science is discussed.Stroboscopic picture of atomic motions in the vicinity of discrete breather excited in graphene homogeneously strained with ϵxx=0.3, ϵyy=−0.1. Displacements of atoms from the equilibrium lattice positions are multiplied by the factor 4 for clarity. The discrete breather is of high spatial localization, so that only two atoms oscillate with a large amplitude.
Viewing Sexual Stimuli Associated with Greater Sexual Responsiveness, Not Erectile Dysfunction
Authors: Prause Nicole , Pfaus James 
Published: March 2015

Abstract

Introduction
Time spent viewing visual sexual stimuli (VSS) has the potential to habituate the sexual response and generalize to the partner context.

Aim
The aim of this study was to examine whether the time spent viewing VSS is related to sexual responsiveness felt in the laboratory or with a sexual partner.

Methods
Nontreatment-seeking men (N = 280) reported their weekly average VSS viewing in hours. VSS hours were examined in relation to the sexual arousal experienced while viewing a standardized sexual film in the laboratory and erectile problems experienced with a sexual partner.

Main Outcome Measures
Self-reported sexual arousal in response to sexual films and erectile problems on the International Index of Erectile Function were the main outcome measures.

Results
More hours viewing VSS was related to stronger experienced sexual responses to VSS in the laboratory, was unrelated to erectile functioning with a partner, and was related to stronger desire for sex with a partner.

Conclusions
VSS use within the range of hours tested is unlikely to negatively impact sexual functioning, given that responses actually were stronger in those who viewed more VSS.