bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matrix metalloproteinase inhibitor, doxycycline and progression of calcific aortic valve disease in hyperlipidemic mice
Authors: Jung Jae-Joon , Razavian Mahmoud , Kim Hye-Yeong , Ye Yunpeng , Golestani Reza , Toczek Jakub , Zhang Jiasheng , Sadeghi Mehran M. 
Published: September 2016

AbstractCalcific aortic valve disease (CAVD) is the most common cause of aortic stenosis. Currently, there is no non-invasive medical therapy for CAVD. Matrix metalloproteinases (MMPs) are upregulated in CAVD and play a role in its pathogenesis. Here, we evaluated the effect of doxycycline, a nonselective MMP inhibitor on CAVD progression in the mouse. Apolipoprotein (apo)E−/− mice (n = 20) were fed a Western diet (WD) to induce CAVD. After 3 months, half of the animals was treated with doxycycline, while the others continued WD alone. After 6 months, we evaluated the effect of doxycycline on CAVD progression by echocardiography, MMP-targeted micro single photon emission computed tomography (SPECT)/computed tomography (CT), and tissue analysis. Despite therapeutic blood levels, doxycycline had no significant effect on MMP activation, aortic valve leaflet separation or flow velocity. This lack of effect on in vivo images was confirmed on tissue analysis which showed a similar level of aortic valve gelatinase activity, and inflammation between the two groups of animals. In conclusion, doxycycline (100 mg/kg/day) had no effect on CAVD progression in apoE−/− mice with early disease. Studies with more potent and specific inhibitors are needed to establish any potential role of MMP inhibition in CAVD development and progression.
First step to investigate nature of electronic states and transport in flower-like MoS2: Combining experimental studies with computational calculations
Authors: Pandey Kavita , Yadav Pankaj , Singh Deobrat , Gupta Sanjeev K. , Sonvane Yogesh , Lukačević Igor , Kim Joondong , Kumar Manoj 
Published: September 2016

AbstractIn the present paper, the nature of electronic states and transport properties of nanostructured flower-like molybdenum disulphide grown by hydrothermal route has been studied. The band structure, electronic nature of charge, thermodynamics and the limit of phonon scattering through density functional theory (DFT) has also been studied. The band tail states, dynamics of trap states and transport of carriers was investigated through intensive impedance spectroscopy analysis. The direct fingerprint of density and band tail state is analyzed from the capacitance plot as capacitance reflects the capability of a semiconductor to accept or release the charge carriers with a corresponding change in its Fermi potential levels. A recently introduced infrared photo-carrier radiometry and density functional perturbation theory (DFPT) techniques have been used to determine the temperature dependence of carrier mobility in flower type-MoS2. The present study illustrates that a large amount of trapped charges leads to an underestimation of the measured effective mobility and the potential of the material. Thus, a continuous engineering effort is required to improve the quality of fabricated nanostructures for its potential applications.
Phase correlation imaging of unlabeled cell dynamics
Authors: Ma Lihong , Rajshekhar Gannavarpu , Wang Ru , Bhaduri Basanta , Sridharan Shamira , Mir Mustafa , Chakraborty Arindam , Iyer Rajashekar , Prasanth Supriya , Millet Larry , Gillette Martha U. , Popescu Gabriel 
Published: September 2016

AbstractWe present phase correlation imaging (PCI) as a novel approach to study cell dynamics in a spatially-resolved manner. PCI relies on quantitative phase imaging time-lapse data and, as such, functions in label-free mode, without the limitations associated with exogenous markers. The correlation time map outputted in PCI informs on the dynamics of the intracellular mass transport. Specifically, we show that PCI can extract quantitatively the diffusion coefficient map associated with live cells, as well as standard Brownian particles. Due to its high sensitivity to mass transport, PCI can be applied to studying the integrity of actin polymerization dynamics. Our results indicate that the cyto-D treatment blocking the actin polymerization has a dominant effect at the large spatial scales, in the region surrounding the cell. We found that PCI can distinguish between senescent and quiescent cells, which is extremely difficult without using specific markers currently. We anticipate that PCI will be used alongside established, fluorescence-based techniques to enable valuable new studies of cell function.
The association between phosphatase and tensin homolog hypermethylation and patients with breast cancer, a meta-analysis and literature review
Authors: Lu Yi-Min , Cheng Feng , Teng Li-Song 
Published: September 2016

AbstractThe Phosphatase and tensin homolog (PTEN) protein is a negative regulator of the Akt pathway, leading to suppression of apoptois and increased cell survival. Its role as a tumor-suppressor gene has been adequately substantiated, and PTEN hypermethylation has been demonstrated in familial and sporadic cancers. However, the association and clinical significance between PTEN hypermethylation and breast cancer remains unclear. In this study, we systematically reviewed studies of PTEN hypermethylation and breast cancer and quantify the association between PTEN hypermethylation and breast cancer using meta-analysis methods. The pooled OR, 22.30, 95% confidential intervals, CI = 1.98–251.51, P = 0.01, which demonstrates that loss of PTEN expression by hypermethylation plays a critical role in the early tumorigenesis of ductal carcinoma in situ (DCIS). In addition, PTEN hypermethylation also is detected in invasive ductal carcinomas (IDCs) and is significantly higher than in normal controls, OR = 23.32, 95% CI = 10.43–52.13, P < 0.00001. Further analysis did not show significant correlation between PTEN hypermethylation and the progression of breast cancer, estrogen receptor (ER), progesterone receptor (PgR), as well as HER2 status. These results indicate the PTEN hypermethylation is significantly associated with both DCIS and IDCs. The detection of PTEN hypermethylation could be an early tumorigenesis marker for breast cancer patients.
Osteogenic differentiation of preosteoblasts on a hemostatic gelatin sponge
Authors: Kuo Zong-Keng , Lai Po-Liang , Toh Elsie Khai-Woon , Weng Cheng-Hsi , Tseng Hsiang-Wen , Chang Pei-Zen , Chen Chih-Chen , Cheng Chao-Min 
Published: September 2016

AbstractBone tissue engineering provides many advantages for repairing skeletal defects. Although many different kinds of biomaterials have been used for bone tissue engineering, safety issues must be considered when using them in a clinical setting. In this study, we examined the effects of using a common clinical item, a hemostatic gelatin sponge, as a scaffold for bone tissue engineering. The use of such a clinically acceptable item may hasten the translational lag from laboratory to clinical studies. We performed both degradation and biocompatibility studies on the hemostatic gelatin sponge, and cultured preosteoblasts within the sponge scaffold to demonstrate its osteogenic differentiation potential. In degradation assays, the gelatin sponge demonstrated good stability after being immersed in PBS for 8 weeks (losing only about 10% of its net weight and about 54% decrease of mechanical strength), but pepsin and collagenases readily biodegraded it. The gelatin sponge demonstrated good biocompatibility to preosteoblasts as demonstrated by MTT assay, confocal microscopy, and scanning electron microscopy. Furthermore, osteogenic differentiation and the migration of preosteoblasts, elevated alkaline phosphatase activity, andin vitromineralization were observed within the scaffold structure. Each of these results indicates that the hemostatic gelatin sponge is a suitable scaffold for bone tissue engineering.
Quenched Magnon excitations by oxygen sublattice reconstruction in (SrCuO2)n/(SrTiO3)2 superlattices
Authors: Dantz M. , Pelliciari J. , Samal D. , Bisogni V. , Huang Y. , Olalde-Velasco P. , Strocov V. N. , Koster G. , Schmitt T. 
Published: September 2016

AbstractThe recently discovered structural reconstruction in the cuprate superlattice (SrCuO2)n/(SrTiO3)2 has been investigated across the critical value of n = 5 using resonant inelastic x-ray scattering (RIXS). We find that at the critical value of n, the cuprate layer remains largely in the bulk-like two-dimensional structure with a minority of Cu plaquettes being reconstructed. The partial reconstruction leads to quenching of the magnons starting at the Γ-point due to the minority plaquettes acting as scattering points. Although comparable in relative abundance, the doped charge impurities in electron-doped cuprate superconductors do not show this quenching of magnetic excitations.
Strong light scattering and broadband (UV to IR) photoabsorption in stretchable 3D hybrid architectures based on Aerographite decorated by ZnO nanocrystallites
Authors: Tiginyanu Ion , Ghimpu Lidia , Gröttrup Jorit , Postolache Vitalie , Mecklenburg Matthias , Stevens-Kalceff Marion A. , Ursaki Veaceslav , Payami Nader , Feidenhansl Robert , Schulte Karl , Adelung Rainer , Mishra Yogendra Kumar 
Published: September 2016

AbstractIn present work, the nano- and microscale tetrapods from zinc oxide were integrated on the surface of Aerographite material (as backbone) in carbon-metal oxide hybrid hierarchical network via a simple and single step magnetron sputtering process. The fabricated hybrid networks are characterized for morphology, microstructural and optical properties. The cathodoluminescence investigations revealed interesting luminescence features related to carbon impurities and inherent host defects in zinc oxide. Because of the wide bandgap of zinc oxide and its intrinsic defects, the hybrid network absorbs light in the UV and visible regions, however, this broadband photoabsorption behavior extends to the infrared (IR) region due to the dependence of the optical properties of ZnO architectures upon size and shape of constituent nanostructures and their doping by carbon impurities. Such a phenomenon of broadband photoabsorption ranging from UV to IR for zinc oxide based hybrid materials is novel. Additionally, the fabricated network exhibits strong visible light scattering behavior. The developed Aerographite/nanocrystalline ZnO hybrid network materials, equipped with broadband photoabsorption and strong light scattering, are very promising candidates for optoelectronic technologies.
Effect of X-ray irradiation on ancient DNA in sub-fossil bones – Guidelines for safe X-ray imaging
Authors: Immel Alexander , Le Cabec Adeline , Bonazzi Marion , Herbig Alexander , Temming Heiko , Schuenemann Verena J. , Bos Kirsten I. , Langbein Frauke , Harvati Katerina , Bridault Anne , Pion Gilbert , Julien Marie-Anne , Krotova Oleksandra , Conard Nicholas J. , Münzel Susanne C. , Drucker Dorothée G. , Viola Bence , Hublin Jean-Jacques , Tafforeau Paul , Krause Johannes 
Published: September 2016

AbstractSub-fossilised remains may still contain highly degraded ancient DNA (aDNA) useful for palaeogenetic investigations. Whether X-ray computed [micro-] tomography ([μ]CT) imaging of these fossils may further damage aDNA remains debated. Although the effect of X-ray on DNA in living organisms is well documented, its impact on aDNA molecules is unexplored. Here we investigate the effects of synchrotron X-ray irradiation on aDNA from Pleistocene bones. A clear correlation appears between decreasing aDNA quantities and accumulating X-ray dose-levels above 2000 Gray (Gy). We further find that strong X-ray irradiation reduces the amount of nucleotide misincorporations at the aDNA molecule ends. No representative effect can be detected for doses below 200 Gy. Dosimetry shows that conventional μCT usually does not reach the risky dose level, while classical synchrotron imaging can degrade aDNA significantly. Optimised synchrotron protocols and simple rules introduced here are sufficient to ensure that fossils can be scanned without impairing future aDNA studies.
The role of exopolymeric substances in the bioaccumulation and toxicity of Ag nanoparticles to algae
Authors: Zhou Kaijun , Hu Yi , Zhang Luqing , Yang Kun , Lin Daohui 
Published: September 2016

AbstractExopolymeric substances (EPS) have an important role in bioaccumulation and toxicity of nanoparticles (NPs) to algae, which warrants specific studies. The interaction of EPS with citrate and polyvinyl pyrrolidone (PVP) coated AgNPs (C-AgNPs and P-AgNPs, respectively) and its roles in bioaccumulation and toxicity of the AgNPs to Chlorella pyrenoidosa were investigated. The amino and aromatic carboxylic groups in the EPS were involved in the EPS-AgNP interactions. Compared with Ag+, C-AgNPs had comparable total bioaccumulation but greater absorption by intact algae with EPS; P-AgNPs had the smallest total bioaccumulation and were mainly adsorbed on algal surfaces. With EPS removed, the total bioaccumulations and surface adsorptions for the three Ag species decreased but the cell internalizations increased; the 96 h half growth inhibition concentrations decreased, indicating EPS alleviated the algal toxicity of Ag. The cell-internalized but not the adsorbed AgNPs could contribute to the nanotoxicity. The EPS could bind both AgNPs and Ag+, and thus inhibited the cell internalization and the nanotoxicity. However, the EPS-bound Ag on the cell surfaces would migrate along with the algae and be biologically amplified in the aquatic food chains, presenting ecological risks. These results are helpful for understanding the fate and ecological effects of NPs.
ITF promotes migration of intestinal epithelial cells through crosstalk between the ERK and JAK/STAT3 pathways
Authors: Le Juan , Zhang Duan Y. , Zhao Yong , Qiu Wei , Wang Peng , Sun Yong 
Published: September 2016

AbstractIntestinal trefoil factor (ITF), a member of the trefoil factor family, is a “Super-protective factor” for intestinal mucosal protection. This study was designed to explore the mechanism by which ITF promotes intestinal epithelial cell migration. Intestinal epithelial cells were treated with the human ITF (hITF). Phospho-ERK, phospho-STAT3 Tyr705, and phospho-STAT3 Ser727 levels were detected at different time points by western blot. To assess the potential crosstalk between the ERK and JAK/STAT3 pathways, HT-29 cells were treated with the MEK-inhibitor, U0126, and phosphor-STAT3 levels were evaluated. Conversely, cells were treated with the JAK-inhibitor, AG490, and ERK-activity was evaluated. Transwell assay was performed to investigate the effect of the crosstalk on the cell motility. MMP-2 and MMP-9 transcription was analyzed by quantitative real-time PCR. E-cadherin degradation was detected by immunofluorescence. Our results indicate that hITF simultaneously activated the ERK and JAK/STAT3 pathways and a crosstalk was detected between the two pathways. hITF increased cell migration. This effect was abolished by U0126 and AG490 treatment. hITF increased MMP2 and MMP9 mRNA levels and E-cadherin degradation and U0126 and AG490 abolished this effect of hITF. In conclusion, the hITF-induced crosstalk between the ERK and JAK/STAT3 pathways is associated with intestinal epithelial cell migration.
Elastic instabilities in planar elongational flow of monodisperse polymer solutions
Authors: Haward Simon J. , McKinley Gareth H. , Shen Amy Q. 
Published: September 2016

AbstractWe investigate purely elastic flow instabilities in the almost ideal planar stagnation point elongational flow field generated by a microfluidic optimized-shape cross-slot extensional rheometer (OSCER). We use time-resolved flow velocimetry and full-field birefringence microscopy to study the behavior of a series of well-characterized viscoelastic polymer solutions under conditions of low fluid inertia and over a wide range of imposed deformation rates. At low deformation rates the flow is steady and symmetric and appears Newtonian-like, while at high deformation rates we observe the onset of a flow asymmetry resembling the purely elastic instabilities reported in standard-shaped cross-slot devices. However, for intermediate rates, we observe a new type of elastic instability characterized by a lateral displacement and time-dependent motion of the stagnation point. At the onset of this new instability, we evaluate a well-known dimensionless criterionMthat predicts the onset of elastic instabilities based on geometric and rheological scaling parameters. The criterion yields maximum values ofMwhich compare well with critical values ofMfor the onset of elastic instabilities in viscometric torsional flows. We conclude that the same mechanism of tension acting along curved streamlines governs the onset of elastic instabilities in both extensional (irrotational) and torsional (rotational) viscoelastic flows.
Sodium nitrite exerts an antihypertensive effect and improves endothelial function through activation of eNOS in the SHR
Authors: Ling Wei Chih , Murugan Dharmani Devi , Lau Yeh Siang , Vanhoutte Paul M. , Mustafa Mohd Rais 
Published: September 2016

AbstractSodium nitrite (NaNO2) induces relaxation in isolated arteries partly through an endothelium-dependent mechanism involving NO-eNOS-sGC-cGMP pathway. The present study was designed to investigate the effect of chronic NaNO2 administration on arterial systolic blood pressure (SBP) and vascular function in hypertensive rats. NaNO2 (150 mg L−1) was given in drinking water for four weeks to spontaneously (SHR) and Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) treated hypertensive SD rats. Arterial SBP and vascular function in isolated aortae were studied. Total plasma nitrate/nitrite and vascular cyclic guanosine monophosphate (cGMP) levels were measured using commercially available assay kits. Vascular nitric oxide (NO) levels were evaluated by DAF-FM fluorescence while the proteins involved in endothelial nitric oxide synthase (eNOS) activation was determined by Western blotting. NaNO2 treatment reduced SBP, improved the impaired endothelium-dependent relaxation, increased plasma total nitrate/nitrite level and vascular tissue NO and cGMP levels in SHR. Furthermore, increased presence of phosphorylated eNOS and Hsp-90 was observed in NaNO2-treated SHR. The beneficial effect of nitrite treatment was not observed in L-NAME treated hypertensive SD rats. The present study provides evidence that chronic treatment of genetically hypertensive rats with NaNO2 improves endothelium-dependent relaxation in addition to its antihypertensive effect, partly through mechanisms involving activation of eNOS.
Half-metallicity and ferromagnetism in penta-AlN2 nanostructure
Authors: Li Jiao , Fan Xinyu , Wei Yanpei , Liu Haiying , Li Shujuan , Zhao Peng , Chen Gang 
Published: September 2016

AbstractWe have performed a detailed first-principles study of the penta-AlN2 nanostructure in the Cairo pentagonal tiling geometry, which is dynamically stable due to the absence of imaginary mode in the calculated phonon spectrum. The formation energy and the fragment cohesive energy analyses, the molecular dynamics simulations, and the mechanical property studies also support the structural stability. It could withstand the temperature as high as 1400 K and sustain the strain up to 16.1% against structural collapse. The slightly buckled penta-AlN2 is found to be a ferromagnetic semiconductor. The strain of ~9% could drive the structural transition from the buckled to the planar. Interestingly, the strain of >7% would change the conducting properties to show half-metallic characters. Furthermore, it could be also used to continuously enhance the magnetic coupling strength, rendering penta-AlN2 as a robust ferromagnetic material. These studies shed light on the possibilities in synthesizing penta-AlN2 and present many unique properties, which are worth of further studying on both theory and experiment.
The dynamic nature of crystal growth in pores
Authors: Godinho Jose R. A. , Gerke Kirill M. , Stack Andrew G. , Lee Peter D. 
Published: September 2016

AbstractThe kinetics of crystal growth in porous media controls a variety of natural processes such as ore genesis and crystallization induced fracturing that can trigger earthquakes and weathering, as well as, sequestration of CO2 and toxic metals into geological formations. Progress on understanding those processes has been limited by experimental difficulties of dynamically studying the reactive surface area and permeability during pore occlusion. Here, we show that these variables cause a time-dependency of barite growth rates in microporous silica. The rate is approximately constant and similar to that observed on free surfaces if fast flow velocities predominate and if the time-dependent reactive surface area is accounted for. As the narrower flow paths clog, local flow velocities decrease, which causes the progressive slowing of growth rates. We conclude that mineral growth in a microporous media can be estimated based on free surface studies when a) the growth rate is normalized to the time-dependent surface area of the growing crystals, and b) the local flow velocities are above the limit at which growth is transport-limited. Accounting for the dynamic relation between microstructure, flow velocity and growth rate is shown to be crucial towards understanding and predicting precipitation in porous rocks.
A novel ethanol gas sensor based on TiO2/Ag0.35V2O5 branched nanoheterostructures
Authors: Wang Yuan , Liu Lixin , Meng Chuanmin , Zhou Yun , Gao Zhao , Li Xuhai , Cao Xiuxia , Xu Liang , Zhu Wenjun 
Published: September 2016

AbstractMuch greater surface-to-volume ratio of hierarchical nanostructures renders them attract considerable interest as prototypical gas sensors. In this work, a novel resistive gas sensor based on TiO2/Ag0.35V2O5 branched nanoheterostructures is fabricated by a facile one-step synthetic process and the ethanol sensing performance of this device is characterized systematically, which shows faster response/recovery behavior, better selectivity, and higher sensitivity of about 9 times as compared to the pure TiO2 nanofibers. The enhanced sensitivity of the TiO2/Ag0.35V2O5 branched nanoheterostructures should be attributed to the extraordinary branched hierarchical structures and TiO2/Ag0.35V2O5 heterojunctions, which can eventually result in an obvious change of resistance upon ethanol exposure. This study not only indicates the gas sensing mechanism for performance enhancement of branched nanoheterostructures, but also proposes a rational approach to design nanostructure based chemical sensors with desirable performance.