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Find video protocols related to scientific articles indexed in Pubmed.
Strong vortical flows generated by the collective motion of magnetic particle chains rotating in a fluid cell.
Lab Chip
PUBLISHED: 11-08-2014
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Magnetic microparticles, assembled into chains that are actuated with rotating magnetic fields, can be used as microstirrers to promote fluid transport and biochemical reactions in microfluidic systems. We show that, within a certain range of magnetic field rotation frequency, the microstirrers exhibit a coherent collective motion: the rotating magnetic particle chains move throughout the volume of a flat fluid cell and generate very strong (~1 mm s(-1)) and global (9 mm) vortical fluid flows, with many eddy-type substructures that fluctuate continuously in time, resembling turbulent flow. The collective motion makes the microstirrers not only defy gravity, but also move against magnetic field gradients. The induced fluid flow is directly related to the stirring rate and the amount of magnetic particle chains. The observed behavior is caused by the magnetic and hydrodynamic interactions between the magnetic microparticles and the fluid. We utilized the phenomenon of swarming particles to enhance biochemical assays with magnetic capture particles (4000 ?L(-1)) and IgG targets (500 pM). When compared to a reference system of sedimented magnetic capture particles, magnetic actuation leads to both a ~9 times increase in the initial assay kinetics as well as a ~7 times increase of target capture signal after 30 minutes.
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A JOINT FRAMEWORK FOR 4D SEGMENTATION AND ESTIMATION OF SMOOTH TEMPORAL APPEARANCE CHANGES.
Proc IEEE Int Symp Biomed Imaging
PUBLISHED: 10-31-2014
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Medical imaging studies increasingly use longitudinal images of individual subjects in order to follow-up changes due to development, degeneration, disease progression or efficacy of therapeutic intervention. Repeated image data of individuals are highly correlated, and the strong causality of information over time lead to the development of procedures for joint segmentation of the series of scans, called 4D segmentation. A main aim was improved consistency of quantitative analysis, most often solved via patient-specific atlases. Challenging open problems are contrast changes and occurance of subclasses within tissue as observed in multimodal MRI of infant development, neurodegeneration and disease. This paper proposes a new 4D segmentation framework that enforces continuous dynamic changes of tissue contrast patterns over time as observed in such data. Moreover, our model includes the capability to segment different contrast patterns within a specific tissue class, for example as seen in myelinated and unmyelinated white matter regions in early brain development. Proof of concept is shown with validation on synthetic image data and with 4D segmentation of longitudinal, multimodal pediatric MRI taken at 6, 12 and 24 months of age, but the methodology is generic w.r.t. different application domains using serial imaging.
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[Calculating method for crop water requirement based on air temperature].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 10-28-2014
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The importance of accurately estimating crop water requirement for irrigation forecast and agricultural water management has been widely recognized. Although it has been broadly adopted to determine crop evapotranspiration (ETc) via meteorological data and crop coefficient, most of the data in whether forecast are qualitative rather than quantitative except air temperature. Therefore, in this study, how to estimate ETc precisely only using air temperature data in forecast was explored, the accuracy of estimation based on different time scales was also investigated, which was believed to be beneficial to local irrigation forecast as well as optimal management of water and soil resources. Three parameters of Hargreaves equation and two parameters of McClound equation were corrected by using meteorological data of Xinxiang from 1970 to 2010, and Hargreaves equation was selected to calculate reference evapotranspiration (ET0) during the growth period of winter wheat. A model of calculating crop water requirement was developed to predict ETc at time scales of 1, 3, and 7 d intervals through combining Hargreaves equation and crop coefficient model based on air temperature. Results showed that the correlation coefficients between measured and predicted values of ETc reached 0.883 (1 d), 0.933 (3 d), and 0.959 (7 d), respectively. The consistency indexes were 0.94, 0.95 and 0.97, respectively, which showed that forecast error decreased with the increasing time scales. Forecasted accuracy with an error less than 1 mm x d(-1) was more than 80%, and that less than 2 mm x d(-1) was greater than 90%. This study provided sound basis for irrigation forecast and agricultural management in irrigated areas since the forecasted accuracy at each time scale was relatively high.
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High-precision rolling angle measurement for a three-dimensional collimator.
Appl Opt
PUBLISHED: 10-17-2014
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We propose a precise rolling angle measurement for a collimator to extend its application in 3D angular deformation measurement, with performance significantly superior to that of the traditional 2D technique. The rolling angle measurement is realized by taking full advantage of the point array image, which is projected in terms of the collimated beam. The measurement error is estimated according to the proposed algorithm. The characteristics of the point array are analyzed to optimize the point array for precise measurement, including the point distribution, the point array resolution, and the point array area. Both simulations and experiments demonstrate that subarcsecond precision rolling angle measurement is achieved by our method, which is superior to those attained by other proposed targets.
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Hericium erinaceus (Yamabushitake): a unique resource for developing functional foods and medicines.
Food Funct
PUBLISHED: 10-15-2014
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Hericium erinaceus (HE) is a fungus inhabiting the mountainous areas of the northeast territories in Asia. HE has been used in traditional folk medicine and medicinal cuisine in China, Korea and Japan. Evidence has been adduced for a variety of physiological effects, including anti-aging, anti-cancer, anti-gastritis, and anti-metabolic disease properties. Hence, HE is an attractive target resource for developing not only medicines, but also functional foods. Basic studies on the physiological functions of HE and on the chemical identification of its active ingredients have progressed in recent decades. In this article, we provide an overview of the biochemical and pharmacological studies on HE, especially of its antitumor and neuroprotective functions, together with a survey of recent developments in the chemical analysis of its polysaccharides, which comprise its major active components.
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Defect-induced strong localization of uranium dicarbide on the graphene surface.
Phys Chem Chem Phys
PUBLISHED: 09-20-2014
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Defects such as the most stable hexavacancy (V6) distribute widely on neutron-irradiated graphite surfaces, which play a dominant role in immobilizing radioactive products released from nuclear fuels. By performing DFT calculations, we explore the interaction of gaseous uranium dicarbide (UC2) molecules on a graphene nanosheet with a V6 defect, in order to investigate the behavior of the representative vapor species of uranium carbide fuels in reactor cores. Results suggest that UC2 can be trapped in the V6 defect with considerable binding energy of >10 eV, with all the six dangling bonds of the V6 defect being saturated by UC2. Bonding nature analyses also reveal that the U-C interaction lies in the synergistic interplay between electrostatic and covalent interaction with extensive participation of U valence electrons from 5f to 7p orbitals, which further stimulate polarization of semi-core 6p orbitals and their subsequent contributions to the bonding. This strong interaction leads to a favorable binding of UC2 to the defective graphite surface, which reduces the capability of nuclear graphite to retain harmful fission products by the vacancies being filled with UC2. These findings highlight substantial chemical reactivity and strong localization of UC2 on the widespread V6 defects in nuclear graphite, and may provide an important reference in establishing modern nuclear reactor safety at the atomic level.
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Dimensionality Reduction for Hyperspectral Data Based on Class-Aware Tensor Neighborhood Graph and Patch Alignment.
IEEE Trans Neural Netw Learn Syst
PUBLISHED: 09-16-2014
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To take full advantage of hyperspectral information, to avoid data redundancy and to address the curse of dimensionality concern, dimensionality reduction (DR) becomes particularly important to analyze hyperspectral data. Exploring the tensor characteristic of hyperspectral data, a DR algorithm based on class-aware tensor neighborhood graph and patch alignment is proposed here. First, hyperspectral data are represented in the tensor form through a window field to keep the spatial information of each pixel. Second, using a tensor distance criterion, a class-aware tensor neighborhood graph containing discriminating information is obtained. In the third step, employing the patch alignment framework extended to the tensor space, we can obtain global optimal spectral-spatial information. Finally, the solution of the tensor subspace is calculated using an iterative method and low-dimensional projection matrixes for hyperspectral data are obtained accordingly. The proposed method effectively explores the spectral and spatial information in hyperspectral data simultaneously. Experimental results on 3 real hyperspectral datasets show that, compared with some popular vector- and tensor-based DR algorithms, the proposed method can yield better performance with less tensor training samples required.
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Contrast enhanced computed tomography is indicative for angiogenesis pattern and display prognostic significance in breast cancer.
BMC Cancer
PUBLISHED: 09-12-2014
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The Prognostic value of microvessel density in cancer remains unclear. Recent studies have suggested that the uneven distribution of microvessels in tumours caused the variation in sample selection which led to different prognostic outcome. The enhancement pattern of Contrast-enhanced computed tomography (CECT) is determined in part by the microvessel distribution in solid tumors. Therefore, survival analysis of tumors grouping by the enhancement pattern and the pattern of microvessel distribution is important.
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[Effect of perioperative treatment with ambroxol on lung cancer patients after video-assisted thoracic surgery lobectomy].
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 09-10-2014
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To evaluate the influence of perioperative intravenous administration of ambroxol on pulmonary function, postoperative complications, postoperative hospital stay, and cost after video-assisted thoracic surgery lobectomy for lung cancer.
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Preparation and pharmacokinetics study on gastro-floating sustained-release tablets of troxipide.
Drug Dev Ind Pharm
PUBLISHED: 09-05-2014
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Abstract The purpose of this research aimed at preparing gastro-floating sustained-release tablets of troxipide and a further study on in vitro release and in vivo bioavailability. Under the circumstances of direct powder compression, the floating tablets were successfully prepared with HPMC as main matrix material, Carbopol as assistant matrix material, octadecanol as floating agent and sodium bicarbonate as foaming agent to float by gas-forming. The floating time and accumulative release amount as evaluation indexes were utilized to perform pre-experiment screening and single-factor test, respectively, while central composite design response surface method was applied for formulation optimization, followed by in vivo pharmacokinetic study in beagles after oral administration for floating tablets and commercial tablets used as the control. The results indicated that the floating sustained-release tablets held a better capability for floating and drug release and more satisfactory pharmacokinetic parameters, such as a lower Cmax, a prolonged Tmax, but an equivalent bioavailability calculated by AUC0-24 compared to commercial tablets. So a conclusion was finally drawn that the floating sustained-release tablets possessing a good release property could be suitable for demands of design.
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Overexpression of FABP7 promotes cell growth and predicts poor prognosis of clear cell renal cell carcinoma.
Urol. Oncol.
PUBLISHED: 09-02-2014
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Renal cell carcinoma (RCC) is one of the most lethal urologic malignancies; however, the molecular events supporting RCC carcinogenesis remain poorly understood. The aim of the present study was to determine the differential expression of genes between normal kidney and clear cell RCC (ccRCC) samples and investigate the biological function of the most frequently altered gene in RCC cells.
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Open carbon nanopipettes as resistive-pulse sensors, rectification sensors, and electrochemical nanoprobes.
Anal. Chem.
PUBLISHED: 09-02-2014
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Nanometer-sized glass and quartz pipettes have been widely used as a core of chemical sensors, patch clamps, and scanning probe microscope tips. Many of those applications require the control of the surface charge and chemical state of the inner pipette wall. Both objectives can be attained by coating the inner wall of a quartz pipette with a nanometer-thick layer of carbon. In this letter, we demonstrate the possibility of using open carbon nanopipettes (CNP) produced by chemical vapor deposition as resistive-pulse sensors, rectification sensors, and electrochemical nanoprobes. By applying a potential to the carbon layer, one can change the surface charge and electrical double-layer at the pipette wall, which, in turn, affect the ion current rectification and adsorption/desorption processes essential for resistive-pulse sensors. CNPs can also be used as versatile electrochemical probes such as asymmetric bipolar nanoelectrodes and dual electrodes based on simultaneous recording of the ion current through the pipette and the current produced by oxidation/reduction of molecules at the carbon nanoring.
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De Novo Design of an Endohedral Heteronuclear Dimetallofullerene (U-Gd)@C60 with Exceptional Structural and Electronic Properties.
Chemphyschem
PUBLISHED: 09-01-2014
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Ever since the first synthesis of La@C82 and U@C28 , there has been a growing interest in the study of endohedral metallofullerenes (EMFs) because of their great potential in various applications. Here we design a novel heteronuclear EMF (U-Gd)@C60 , by using density functional theory (DFT), which shows an encapsulation energy of about -5.53?eV, comparable to that of U2 @C60, La2 @C80 , and Lu2 @C76 . (U-Gd)@C60 is found to have a surprising twofold, single-electron U?Gd bond that results from the strong nanoconfinement of the fullerene, dominated by uranium's 5f and 6d and gadolinium's 5d atomic orbitals. The ground state shows an 11-et high spin state, and the net spins distributed on the U-pole carbons are relatively scattered, while they are highly concentrated on the Gd-pole carbons. The exceptional electronic characteristics of this novel EMF, containing both uranium and gadolinium atoms encapsulated, might prove useful for future applications in nuclear energy and biomedicine.
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Accelerating Multiagent Reinforcement Learning by Equilibrium Transfer.
IEEE Trans Cybern
PUBLISHED: 08-29-2014
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{}An important approach in multiagent reinforcement learning (MARL) is equilibrium-based MARL, which adopts equilibrium solution concepts in game theory and requires agents to play equilibrium strategies at each state. However, most existing equilibrium-based MARL algorithms cannot scale due to a large number of computationally expensive equilibrium computations (e.g., computing Nash equilibria is PPAD-hard) during learning. For the first time, this paper finds that during the learning process of equilibrium-based MARL, the one-shot games corresponding to each state's successive visits often have the same or similar equilibria (for some states more than 90% of games corresponding to successive visits have similar equilibria). Inspired by this observation, this paper proposes to use equilibrium transfer to accelerate equilibrium-based MARL. The key idea of equilibrium transfer is to reuse previously computed equilibria when each agent has a small incentive to deviate. By introducing transfer loss and transfer condition, a novel framework called equilibrium transfer-based MARL is proposed. We prove that although equilibrium transfer brings transfer loss, equilibrium-based MARL algorithms can still converge to an equilibrium policy under certain assumptions. Experimental results in widely used benchmarks (e.g., grid world game, soccer game, and wall game) show that the proposed framework: 1) not only significantly accelerates equilibrium-based MARL (up to 96.7% reduction in learning time), but also achieves higher average rewards than algorithms without equilibrium transfer and 2) scales significantly better than algorithms without equilibrium transfer when the state/action space grows and the number of agents increases.
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Curcumin promotes KLF5 proteasome degradation through downregulating YAP/TAZ in bladder cancer cells.
Int J Mol Sci
PUBLISHED: 08-28-2014
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KLF5 (Krüppel-like factor 5) plays critical roles in normal and cancer cell proliferation through modulating cell cycle progression. In this study, we demonstrated that curcumin targeted KLF5 by promoting its proteasome degradation, but not by inhibiting its transcription in bladder cancer cells. We also demonstrated that lentivirus-based knockdown of KLF5 inhibited cancer cell growth, while over-expression of a Flag-tagged KLF5 could partially reverse the effects of curcumin on cell growth and cyclin D1 expression. Furthermore, we found that curcumin could down-regulate the expression of Hippo pathway effectors, YAP and TAZ, which have been reported to protect KLF5 protein from degradation. Indeed, knockdown of YAP by small interfering RNA caused the attenuation of KLF5 protein, but not KLF5 mRNA, which was reversed by co-incubation with proteasome inhibitor. A xenograft assay in nude mice finally proved the potent inhibitory effects of curcumin on tumor growth and the pro-proliferative YAP/TAZ/KLF5/cyclin D1 axis. Thus, our data indicates that curcumin promotes KLF5 proteasome-dependent degradation through targeting YAP/TAZ in bladder cancer cells and also suggests the therapeutic potential of curcumin in the treatment of bladder cancer.
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[Nitrogen leaching and associated environmental health effect in sloping cropland of purple soil].
Huan Jing Ke Xue
PUBLISHED: 08-28-2014
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In this paper, we monitored different forms of nitrogen (N) transported by the subsurface flow under three different natural rainfall events and different fertilizations and conducted an associated risk evaluation on environmental health, which provides scientific basis for controlling N non-point pollution and establishing a reasonable fertilization system in purple soil area. The results showed that there were different forms of N transport by subsurface flow under different rainfall events, where in dissolved nitrogen (DN) accounted for about 53.74% - 99.21%, and nitrate (NO3(-) -N) accounted for about 35.70% - 93.65% of DN, and especially under the moderate rainfall, NO3(-) -N could reach 84.09% - 93.65% of DN. The different N fluxes were the highest under moderate rainfall among different rainfall events, in which the flux of total nitrogen (TN), DN, particle nitrogen (PN), ammonia (NH4(+) -N) and nitrite (NO2(-) -N) reached 737.17, 711.12, 26.06, 12.70 and 0.46 mg x m(-2), respectively, and the NO3(-)-N flux was as high as 686.12 mg x m(-2), showing a huge potential threat on groundwater health. Through the risk assessment on N pollution for groundwater quality, we concluded that the straw returning could be used to effectively alleviate the N leaching and groundwater N pollution; especially, the combined application of organic and chemical fertilizer could effectively mitigate the groundwater pollution, improve soil fertility and increase crop yield.
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The mechanism of N-Ag bonding determined tunability of surface-enhanced Raman scattering of pyridine on MAg (M = Cu, Ag, Au) diatomic clusters.
Phys Chem Chem Phys
PUBLISHED: 08-26-2014
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Binary coinage metal clusters can show a significantly different enhancement in surface-enhanced Raman scattering (SERS) from that of pure element clusters, owing to their tunable surface plasmon resonance energies affected by the composition and atomic ordering. Yet, the tunability by composition requires a deep understanding in order to further optimize the SERS-based detection technique. Here, to fill this deficiency, we conducted detailed analyses of the SERS of pyridine adsorbed through N-Ag bonding on the homonuclear diatomic metal cluster Ag2 and heteronuclear diatomic metal clusters of AuAg and CuAg, as well as the involved charge transfer under an intracluster excitation, based on calculations using time-dependent density functional theory with a short-time approximation for the Raman cross-section. We find that although the SERS enhancements for all complexes can reach the order of 10(3)-10(4), the corresponding wavelengths used for SERS excitation are significantly different. Our molecular orbital analysis reveals that the complexes based on heteronuclear metal clusters can produce varied electronic transitions owing to the polarization between different metal atoms, which tune the SERS enhancements with altered optical properties. Our analyses are expected to provide a theoretical basis for exploring the multi-composition SERS substrates applicable for single molecular detection, nanostructure characterization, and biological molecular identification.
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[Analysis on the relationship between adolescent myopia and serum sex hormone].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-22-2014
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To investigate the quantitative changes of the serum sex hormone levels in juvenile myopia patients.
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Regulation of HPV16 E6 and MCL1 by SF3B1 inhibitor in head and neck cancer cells.
Sci Rep
PUBLISHED: 08-20-2014
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ABT-737 inhibits the anti-apoptotic proteins B-cell lymphoma 2 (BCL-2) and BCL-X(L). Meayamycin B switches the splicing pattern of myeloid cell leukemia factor 1 (MCL1) pre-mRNA. Specifically, inhibition of splicing factor 3B subunit 1 (SF3B1) with meayamycin B promotes the generation of the proapoptotic, short splicing variant (MCL1-S) and diminishes the antiapoptotic, long variant (MCL1-L). This action was previously associated with the cytotoxicity of meayamycin B in non-small cell lung carcinoma cell lines. ABT-737 induced apoptosis in response to an ablation of MCL1-L by meayamycin B. In this study, we further exploited this synergistic combination in head and neck squamous cell carcinoma (HNSCC), up to 90% of which overexpress MCL1 and BCL-X(L). In a panel of seven HNSCC cell lines, the combination of meayamycin B and ABT-737 rapidly triggered a Bax/Bak-mediated apoptosis that overcame the resistance from HPV16-positive HNSCC against each agent alone. Both RT-PCR and Western blotting showed that meayamycin B up-regulated MCL1-S and down-regulated MCL1-L. Significantly, we discovered that SF3B1 was involved in the splicing of oncogenic HPV16 E6 to produce non-oncogenic HPV16 E6*, indicating that SF3B1 may inhibit HPV16-induced tumorigenesis.
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Diruthenium-polyyn-diyl-diruthenium wires: electronic coupling in the long distance regime.
J. Am. Chem. Soc.
PUBLISHED: 08-18-2014
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Reported herein is a series of Ru2(Xap)4 capped polyyn-diyl compounds, where Xap is either 2-anilinopyridinate (ap) or its aniline substituted derivatives. Symmetric [Ru2(Xap)4](?-C4k)[Ru2(Xap)4] (compounds 4ka (X = 3-isobutoxy) and 4kc (X = 3,5-dimethoxy) with k = 2, 3, 4, and 5) was obtained from the Glaser coupling reaction of Ru2(Xap)4(C2kH). Unsymmetric [Ru2(Xap)4](?-C(4k+2))[Ru2(ap)4] (compounds 4k+2b with k = 2, 3, and 4) were prepared from the Glaser coupling reaction between Ru2(Xap)4(C(2k+2)H) and Ru2(ap)4(C2kH). X-ray diffraction study of compound 12c revealed both the sigmoidal topology of the polyyn-diyl bridge and the fine structural detail about the Ru2 cores. Cyclic and differential pulse voltammetric (CV and DPV) measurements and spectroelectrochemical studies revealed that (i) the reduced monoanions [Ru2-C2m-Ru2](-1) (m = 4-8) belong to the Robin-Day class II mixed valent ions and (ii) the electronic coupling between Ru2 termini depends on the length of the polyyn-diyl bridge with an attenuation constant (?) between 0.12 and 0.15 Å(-1). In addition, spin-unrestricted DFT calculations provide insight about the nature of orbitals that mediate the long distance electronic coupling.
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Design, synthesis, and fungicidal evaluation of a series of novel 5-methyl-1H-1,2,3-trizole-4-carboxyl amide and ester analogues.
Eur J Med Chem
PUBLISHED: 08-12-2014
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Succinate dehydrogenase inhibitors (SDHIs) are efficient fungicides that are widely used to control plant diseases caused by phytopathogenic fungi, although their effectiveness is undermined by the development of resistance across a range of different fungi. One of the most common structural features of SDHIs is their amide bond. The introduction of greater structural diversity to SDHIs is a promising strategy to delay the onset of resistance. A series of novel SDHIs containing a bioactive 1,2,3-triazole moiety have been designed and synthesized and their fungicidal and insecticidal activities evaluated. The results of these analyses show that most of the newly synthesized 1,2,3-trizole-4-carboxyl amide (ester) analogues exhibit good fungicidal activities, especially towards Sclerotinia sclerotiorum, and a structure-activity relationship study confirmed that the replacement of the amide group with an ester group had little effect on fungicidal activity, which could be provideous in terms of issues and metabolism. 1,6-Dimethyl phenyl was confirmed as the most efficient substituent of the current study when it was placed on both the amide and ester compounds. Interestingly, some of the newly synthesized compounds displayed good insecticidal activities against Culex pipiens pallens. The results of the current study show that these 1,2,3-triazole-4-carboxyl amide and ester analogues represent a new type of SDHI that could be used for the development of novel pesticides.
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Structurally enhanced incremental neural learning for image classification with subgraph extraction.
Int J Neural Syst
PUBLISHED: 08-12-2014
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In this paper, a structurally enhanced incremental neural learning technique is proposed to learn a discriminative codebook representation of images for effective image classification applications. In order to accommodate the relationships such as structures and distributions among visual words into the codebook learning process, we develop an online codebook graph learning method based on a novel structurally enhanced incremental learning technique, called as "visualization-induced self-organized incremental neural network (ViSOINN)". The hidden structural information in the images is embedded into the graph representation evolving dynamically with the adaptive and competitive learning mechanism. Afterwards, image features can be coded using a sub-graph extraction process based on the learned codebook graph, and a classifier is subsequently used to complete the image classification task. Compared with other codebook learning algorithms originated from the classical Bag-of-Features (BoF) model, ViSOINN holds the following advantages: (1) it learns codebook efficiently and effectively from a small training set; (2) it models the relationships among visual words in metric scaling fashion, so preserving high discriminative power; (3) it automatically learns the codebook without a fixed pre-defined size; and (4) it enhances and preserves better the structure of the data. These characteristics help to improve image classification performance and make it more suitable for handling large-scale image classification tasks. Experimental results on the widely used Caltech-101 and Caltech-256 benchmark datasets demonstrate that ViSOINN achieves markedly improved performance and reduces the computational cost considerably.
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RASSF5 inhibits growth and invasion and induces apoptosis in osteosarcoma cells through activation of MST1/LATS1 signaling.
Oncol. Rep.
PUBLISHED: 08-07-2014
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Ras association (RalGDS/AF-6) domain family member RASSF5 has been implicated in a variety of key biological processes, including cell proliferation, cell cycle regulation and apoptosis. It is believed to play an important role in tumorigenesis as a tumor suppressor in a number of malignancies. Yet, little is known concerning the function and underlying mechanisms of RASSF5 in human osteosarcoma (OS). The expression of RASSF5 was examined by immunohistochemical assay using a tissue microarray in 45 cases of OS tissues. A gain-of-function approach was used to observe the effects of lentiviral vector-mediated overexpression of RASSF5 (Lv-RASSF5) on cell growth, invasion and apoptosis, respectively, as indicated by MTT, Transwell and flow cytometry assays, and the expression levels of mammalian sterile 20-like (MST1) kinase, large tumor suppressor 1 (LATS1), proliferating cell nuclear antigen (PCNA), matrix metallopeptidase-9 (MMP-9) and p53 were detected by real-time PCR and western blot assays in OS cells (MG-63 and U-2 OS). The results indicated that the expression of RASSF5 protein was significantly downregulated in OS tissues compared to that in adjacent non-cancerous tissues (ANCT) (40.0 vs. 73.3%, P=0.002), and had a negative correlation with distant metastasis of the tumor (P=0.01). Overexpression of RASSF5 markedly suppressed cell proliferation and invasion, and induced cell apoptosis in the OS cell lines with increased expression of MST1, LATS1 and p53 and decreased expression of PCNA and MMP-9. Taken together, our findings demonstrate that RASSF5 expression is negatively correlated with distant metastasis of OS, and RASSF5 may function as a tumor suppressor in OS cells through activation of the MST1/LATS1 pathway.
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Screening for markers of frailty and perceived risk of adverse outcomes using the Risk Instrument for Screening in the Community (RISC).
BMC Geriatr
PUBLISHED: 08-05-2014
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Functional decline and frailty are common in community dwelling older adults, increasing the risk of adverse outcomes. Given this, we investigated the prevalence of frailty-associated risk factors and their distribution according to the severity of perceived risk in a cohort of community dwelling older adults, using the Risk Instrument for Screening in the Community (RISC).
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Human herpesvirus 8 viral interleukin-6 signaling through gp130 promotes virus replication in primary effusion lymphoma and endothelial cells.
J. Virol.
PUBLISHED: 07-30-2014
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The contributions of human herpesvirus 8 (HHV-8) viral interleukin-6 (vIL-6) to virus biology remain unclear. Here we examined the role of vIL-6/gp130 signaling in HHV-8 productive replication in primary effusion lymphoma and endothelial cells. Depletion and depletion-complementation experiments revealed that endoplasmic reticulum-localized vIL-6 activity via gp130 and gp130-activated signal transducer and activator of transcription (STAT) signaling, but not extracellular signal-regulated kinase (ERK) activation, was critical for vIL-6 proreplication activity. Our data significantly extend current understanding of vIL-6 function and associated mechanisms in HHV-8 biology.
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Autoinhibition of bacteriophage T4 Mre11 by its C-terminal domain.
J. Biol. Chem.
PUBLISHED: 07-30-2014
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Mre11 and Rad50 form a stable complex (MR) and work cooperatively in repairing DNA double strand breaks. In the bacteriophage T4, Rad50 (gene product 46) enhances the nuclease activity of Mre11 (gene product 47), and Mre11 and DNA in combination stimulate the ATPase activity of Rad50. The structural basis for the cross-activation of the MR complex has been elusive. Various crystal structures of the MR complex display limited protein-protein interfaces that mainly exist between the C terminus of Mre11 and the coiled-coil domain of Rad50. To test the role of the C-terminal Rad50 binding domain (RBD) in Mre11 activation, we constructed a series of C-terminal deletions and mutations in bacteriophage T4 Mre11. Deletion of the RBD in Mre11 eliminates Rad50 binding but only has moderate effect on its intrinsic nuclease activity; however, the additional deletion of the highly acidic flexible linker that lies between RBD and the main body of Mre11 increases the nuclease activity of Mre11 by 20-fold. Replacement of the acidic residues in the flexible linker with alanine elevates the Mre11 activity to the level of the MR complex when combined with deletion of RBD. Nuclease activity kinetics indicate that Rad50 association and deletion of the C terminus of Mre11 both enhance DNA substrate binding. Additionally, a short peptide that contains the flexible linker and RBD of Mre11 acts as an inhibitor of Mre11 nuclease activity. These results support a model where the Mre11 RBD and linker domain act as an autoinhibitory domain when not in complex with Rad50. Complex formation with Rad50 alleviates this inhibition due to the tight association of the RBD and the Rad50 coiled-coil.
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[Application of space-time scan statistics in the analysis of spatial and temporal distribution of Oncomelania hupensis snails in Gaoyou County, Jiangsu Province].
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi
PUBLISHED: 07-29-2014
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To investigate the distribution features of Oncomelania hupensis infested areas in Gaoyou County so as to formulate surveillance and intervention strategies.
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Effects of meteorology and secondary particle formation on visibility during heavy haze events in Beijing, China.
Sci. Total Environ.
PUBLISHED: 07-25-2014
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The causes of haze formation in Beijing, China were analyzed based on a comprehensive measurement, including PBL (planetary boundary layer), aerosol composition and concentrations, and several important meteorological parameters such as visibility, RH (relative humidity), and wind speed/direction. The measurement was conducted in an urban location from Nov. 16, 2012 to Jan. 15, 2013. During the period, the visibility varied from >20km to less than a kilometer, with a minimum visibility of 667m, causing 16 haze occurrences. During the haze occurrences, the wind speeds were less than 1m/s, and the concentrations of PM2.5 (particle matter with radius less than 2.5?m) were often exceeded 200?g/m(3). The correlation between PM2.5 concentration and visibility under different RH values shows that visibility was exponentially decreased with the increase of PM2.5 concentrations when RH was less than 80%. However, when RH was higher than 80%, the relationship was no longer to follow the exponentially decreasing trend, and the visibility maintained in very low values, even with low PM2.5 concentrations. Under this condition, the hygroscopic growth of particles played important roles, and a large amount of water vapor acted as particle matter (PM) for the reduction of visibility. The variations of meteorological parameters (RH, PBL heights, and WS (wind speed)), chemical species in gas-phase (CO, O3, SO2, and NOx), and gas-phase to particle-phase conversions under different visibility ranges were analyzed. The results show that from high visibility (>20km) to low visibility (<2km), the averaged PBL decreased from 1.24km to 0.53km; wind speeds reduced from 1m/s to 0.5m/s; and CO increased from 0.5ppmv to 4.0ppmv, suggesting that weaker transport/diffusion caused the haze occurrences. This study also found that the formation of SPM (secondary particle matter) was accelerated in the haze events. The conversions between SO2 and SO4 as well as NOx to NO3(-) increased, especially under high humidity conditions. When the averaged RH was 70%, the conversions between SO2 and SO4 accounted for about 20% concentration of PM2.5, indicating that formation of secondary particle matter had important contribution for the haze occurrences in Beijing.
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Draft Sequencing and Analysis of the Genome of Pufferfish Takifugu flavidus.
DNA Res.
PUBLISHED: 07-24-2014
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The pufferfish Takifugu flavidus is an important economic species due to its outstanding flavour and high market value. It has been regarded as an excellent model of genetic study for decades as well. In the present study, three mate-pair libraries of T. flavidus genome were sequenced by the SOLiD 4 next-generation sequencing platform, and the draft genome was constructed with the short reads using an assisted assembly strategy. The draft consists of 50,947 scaffolds with an N50 value of 305.7 kb, and the average GC content was 45.2%. The combined length of repetitive sequences was 26.5 Mb, which accounted for 6.87% of the genome, indicating that the compactness of T. flavidus genome was approximative with that of T. rubripes genome. A total of 1,253 non-coding RNA genes and 30,285 protein-encoding genes were assigned to the genome. There were 132,775 and 394 presumptive genes playing roles in the colour pattern variation, the relatively slow growth and the lipid metabolism, respectively. Among them, genes involved in the microtubule-dependent transport system, angiogenesis, decapentaplegic pathway and lipid mobilization were significantly expanded in the T. flavidus genome. This draft genome provides a valuable resource for understanding and improving both fundamental and applied research with pufferfish in the future.
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Implementation of incident learning in the safety and quality management of radiotherapy: the primary experience in a new established program with advanced technology.
Biomed Res Int
PUBLISHED: 07-22-2014
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To explore the implementation of incident learning for quality management of radiotherapy in a new established radiotherapy program.
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Multiagent Reinforcement Learning With Unshared Value Functions.
IEEE Trans Cybern
PUBLISHED: 07-12-2014
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One important approach of multiagent reinforcement learning (MARL) is equilibrium-based MARL, which is a combination of reinforcement learning and game theory. Most existing algorithms involve computationally expensive calculation of mixed strategy equilibria and require agents to replicate the other agents' value functions for equilibrium computing in each state. This is unrealistic since agents may not be willing to share such information due to privacy or safety concerns. This paper aims to develop novel and efficient MARL algorithms without the need for agents to share value functions. First, we adopt pure strategy equilibrium solution concepts instead of mixed strategy equilibria given that a mixed strategy equilibrium is often computationally expensive. In this paper, three types of pure strategy profiles are utilized as equilibrium solution concepts: pure strategy Nash equilibrium, equilibrium-dominating strategy profile, and nonstrict equilibrium-dominating strategy profile. The latter two solution concepts are strategy profiles from which agents can gain higher payoffs than one or more pure strategy Nash equilibria. Theoretical analysis shows that these strategy profiles are symmetric meta equilibria. Second, we propose a multistep negotiation process for finding pure strategy equilibria since value functions are not shared among agents. By putting these together, we propose a novel MARL algorithm called negotiation-based Q-learning (NegoQ). Experiments are first conducted in grid-world games, which are widely used to evaluate MARL algorithms. In these games, NegoQ learns equilibrium policies and runs significantly faster than existing MARL algorithms (correlated Q-learning and Nash Q-learning). Surprisingly, we find that NegoQ also performs well in team Markov games such as pursuit games, as compared with team-task-oriented MARL algorithms (such as friend Q-learning and distributed Q-learning).
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Testosterone regulates keratin 33B expression in rat penis growth through androgen receptor signaling.
Asian J. Androl.
PUBLISHED: 07-05-2014
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Androgen therapy is the mainstay of treatment for the hypogonadotropic hypogonadal micropenis because it obviously enhances penis growth in prepubescent microphallic patients. However, the molecular mechanisms of androgen treatment leading to penis growth are still largely unknown. To clarify this well-known phenomenon, we successfully generated a castrated male Sprague Dawley rat model at puberty followed by testosterone administration. Interestingly, compared with the control group, testosterone treatment stimulated a dose-dependent increase of penis weight, length, and width in castrated rats accompanied with a dramatic recovery of the pathological changes of the penis. Mechanistically, testosterone administration substantially increased the expression of androgen receptor (AR) protein. Increased AR protein in the penis could subsequently initiate transcription of its target genes, including keratin 33B (Krt33b). Importantly, we demonstrated that KRT33B is generally expressed in the rat penis and that most KRT33B expression is cytoplasmic. Furthermore, AR could directly modulate its expression by binding to a putative androgen response element sequence of the Krt33b promoter. Overall, this study reveals a novel mechanism facilitating penis growth after testosterone treatment in precastrated prepubescent animals, in which androgen enhances the expression of AR protein as well as its target genes, such as Krt33b.
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[Carbon sequestration status of forest ecosystems in Ningxia Hui Autonomous Region].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 07-03-2014
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Based on the data of Ningxia Hui Autonomous Region forest resources inventory, field investigation and laboratory analysis, this paper studied the carbon sequestration status of forest ecosystems in Ningxia region, estimated the carbon density and storage of forest ecosystems, and analyzed their spatial distribution characteristics. The results showed that the biomass of each forest vegetation component was in the order of arbor layer (46.64 Mg x hm(-2)) > litterfall layer (7.34 Mg x hm(-2)) > fine root layer (6.67 Mg x hm(-2)) > shrub-grass layer (0.73 Mg x hm(-2)). Spruce (115.43 Mg x hm(-2)) and Pinus tabuliformis (94.55 Mg x hm(-2)) had higher vegetation biomasses per unit area than other tree species. Over-mature forest had the highest arbor carbon density among the forests with different ages. However, the young forest had the highest arbor carbon storage (1.90 Tg C) due to its widest planted area. Overall, the average carbon density of forest ecosystems in Ningxia region was 265.74 Mg C x hm(-2), and the carbon storage was 43.54 Tg C. Carbon density and storage of vegetation were 27.24 Mg C x hm(-2) and 4.46 Tg C, respectively. Carbon storage in the soil was 8.76 times of that in the vegetation. In the southern part of Ningxia region, the forest carbon storage was higher than in the northern part, where the low C storage was mainly related to the small forest area and young forest age structure. With the improvement of forest age structure and the further implementation of forestry ecoengineering, the forest ecosystems in Ningxia region would achieve a huge carbon sequestration potential.
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Two-photon polymerization: investigation of chemical and mechanical properties of resins using Raman microspectroscopy.
Opt Lett
PUBLISHED: 07-01-2014
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In this study, the degree of conversion (DC) of an acrylic-based resin (IP-L 780) in two-photon polymerization (TPP) is systematically investigated via Raman microspectroscopy. A quantitative relationship between TPP laser parameters and the DC of the resin is established. Nonlinear increase in DC with increased laser average power is observed. The resin DC is more sensitive to the laser average power than the laser writing speed. Nanoindentation was employed to correlate the results obtained from Raman microspectroscopy with the mechanical properties of microstructures fabricated by TPP. At constant writing speeds, microstructures fabricated with high laser average powers possess high hardness and high reduced Young's modulus (RYM), indicating high DCs. The results are in line with high DCs measured under the same TPP parameters in Raman microspectroscopy. Raman microspectroscopy is proved to be an effective, rapid, and nondestructive method characterizing microstructures fabrication by TPP.
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Low-dose X-ray computed tomography image reconstruction with a combined low-mAs and sparse-view protocol.
Opt Express
PUBLISHED: 07-01-2014
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To realize low-dose imaging in X-ray computed tomography (CT) examination, lowering milliampere-seconds (low-mAs) or reducing the required number of projection views (sparse-view) per rotation around the body has been widely studied as an easy and effective approach. In this study, we are focusing on low-dose CT image reconstruction from the sinograms acquired with a combined low-mAs and sparse-view protocol and propose a two-step image reconstruction strategy. Specifically, to suppress significant statistical noise in the noisy and insufficient sinograms, an adaptive sinogram restoration (ASR) method is first proposed with consideration of the statistical property of sinogram data, and then to further acquire a high-quality image, a total variation based projection onto convex sets (TV-POCS) method is adopted with a slight modification. For simplicity, the present reconstruction strategy was termed as "ASR-TV-POCS." To evaluate the present ASR-TV-POCS method, both qualitative and quantitative studies were performed on a physical phantom. Experimental results have demonstrated that the present ASR-TV-POCS method can achieve promising gains over other existing methods in terms of the noise reduction, contrast-to-noise ratio, and edge detail preservation.
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Total Synthesis and Biological Studies of TMC-205 and Analogues as Anticancer Agents and Activators of SV40 Promoter.
ACS Med Chem Lett
PUBLISHED: 06-23-2014
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TMC-205 is a natural fungal metabolite with antiproliferative activity against cancer cell lines. The light- and air-sensitivity prevented in-depth exploitation of this novel indole derivative. Herein, we report the first synthesis of TMC-205. On the basis of its reactivity with reactive oxygen species, we developed air-stable analogues of TMC-205. These analogues are 2-8-fold more cytotoxic than TMC-205 against HCT-116 colon cancer cell line. Importantly, at noncytotoxic dose levels, these analogues activated the transcription of luciferase reporter gene driven by simian virus 40 promoter (SV40). Further, these small molecules also inhibit firefly luciferase, presumably by direct interaction.
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Pd-Catalyzed C-H activation/oxidative cyclization of acetanilide with norbornene: concise access to functionalized indolines.
Chem. Commun. (Camb.)
PUBLISHED: 06-20-2014
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An efficient Pd-catalyzed oxidative cyclization reaction for the synthesis of functionalized indolines by direct C-H activation of acetanilide has been developed. The norbornylpalladium species formed via direct ortho C-H activation of acetanilides is supposed to be a key intermediate in this transformation.
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Misdiagnosis of pancreatic papillary mucinous cystadenocarcinoma: A case report.
Oncol Lett
PUBLISHED: 06-12-2014
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The morbidity of papillary cystadenocarcinoma of the pancreas is extremely low and the condition is rarely first found as spinal metastases, thus it is often misdiagnosed prior to surgery. The present study reports a case of papillary cystadenocarcinoma with thoracolumbar metastases in a 56-year-old male. The first symptom to occur was backache, however, computed tomography revealed no positive findings. The pain became exacerbated and the patient underwent lumbar and thoracic vertebrae magnetic resonance imaging, which identified abnormal signals. Imaging and pathological examinations were used for the final diagnosis. Due to multiple bone metastases, the patient the administration of induction chemotherapy was suggested, however, the patient refused. The patient succumbed to the disease in June 2013.
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The mammalian target of rapamycin pathway in the basolateral amygdala is critical for nicotine-induced behavioural sensitization.
Int. J. Neuropsychopharmacol.
PUBLISHED: 06-11-2014
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Repeated exposure to nicotine increases psychomotor activity. Long-lasting neural plasticity changes that contribute to the nicotine-induced development of locomotor sensitization have been identified. The mammalian target of rapamycin complex 1 (mTORC1) signalling pathway is involved in regulating the neuroplasticity of the central nervous system. In this study, we examined the role of mTORC1 in the amygdala in nicotine-induced locomotor sensitization. Rapamycin, an inhibitor of mTORC1, was infused into the basolateral amygdala (BLA) and central amygdala (CeA) or systemically administered to investigate the role of the mTORC1 in the development and expression of nicotine-induced locomotor sensitization. We found that locomotor activity progressively increased during the initiation of nicotine-induced locomotor sensitization and the expression of nicotine sensitization was induced by nicotine challenge injection (0.35 mg/kg s.c.) after five days of withdrawal. The initiation of nicotine-induced locomotor sensitization was accompanied by the increased phosphorylated level of mTORC1 downstream target proteins including p-p70s6k and p-4EBP in the BLA, but not CeA. Intra-BLA infusion or systemic administration of rapamycin blocked locomotor activity. Increased p-p70s6k and p-4EBP were also observed in the expression of nicotine sensitization, which was demonstrated to be inhibited by systemic rapamycin administration. Our findings indicated that mTORC1 activity in the BLA, but not the CeA, mediated the initiation and expression of nicotine-induced locomotor sensitization, and may become a potential target for the treatment of nicotine addiction.
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Carbon accumulation in a permafrost polygon peatland: steady long-term rates in spite of shifts between dry and wet conditions.
Glob Chang Biol
PUBLISHED: 06-10-2014
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Ice-wedge polygon peatlands contain a substantial part of the carbon stored in permafrost soils. However, little is known about their long-term carbon accumulation rates (CAR) in relation to shifts in vegetation and climate. We collected four peat profiles from one single polygon in NE Yakutia and cut them into contiguous 0.5 cm slices. Pollen density interpolation between AMS (14) C dated levels provided the time span contained in each of the sample slices, which - in combination with the volumetric carbon content - allowed for the reconstruction of CAR over decadal and centennial timescales. Vegetation representing dry palaeo-ridges and wet depressions was reconstructed with detailed micro- and macrofossil analysis. We found repeated shifts between wet and dry conditions during the past millennium. Dry ridges with associated permafrost growth originated during phases of (relatively) warm summer temperature and collapsed during relatively cold phases, illustrating the important role of vegetation and peat as intermediaries between ambient air temperature and the permafrost. The average long-term CAR across the four profiles was 10.6 ± 5.5 g C m(-2)  yr(-1) . Time-weighted mean CAR did not differ significantly between wet depression and dry ridge/hummock phases (10.6 ± 5.2 g C m(-2)  yr(-1) and 10.3 ± 5.7 g C m(-2)  yr(-1) , respectively). Although we observed increased CAR in relation to warm shifts, we also found changes in the opposite direction and the highest CAR actually occurred during the Little Ice Age. In fact, CAR rather seems to be governed by strong internal feedback mechanisms and has roughly remained stable on centennial time scales. The absence of significant differences in CAR between dry ridge and wet depression phases suggests that recent warming and associated expansion of shrubs will not affect long-term rates of carbon burial in ice-wedge polygon peatlands.
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Modeling insurer-homeowner interactions in managing natural disaster risk.
Risk Anal.
PUBLISHED: 06-10-2014
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The current system for managing natural disaster risk in the United States is problematic for both homeowners and insurers. Homeowners are often uninsured or underinsured against natural disaster losses, and typically do not invest in retrofits that can reduce losses. Insurers often do not want to insure against these losses, which are some of their biggest exposures and can cause an undesirably high chance of insolvency. There is a need to design an improved system that acknowledges the different perspectives of the stakeholders. In this article, we introduce a new modeling framework to help understand and manage the insurer's role in catastrophe risk management. The framework includes a new game-theoretic optimization model of insurer decisions that interacts with a utility-based homeowner decision model and is integrated with a regional catastrophe loss estimation model. Reinsurer and government roles are represented as bounds on the insurer-insured interactions. We demonstrate the model for a full-scale case study for hurricane risk to residential buildings in eastern North Carolina; present the results from the perspectives of all stakeholders-primary insurers, homeowners (insured and uninsured), and reinsurers; and examine the effect of key parameters on the results.
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Upregulation of hepatic VLDLR via PPAR? is required for the triglyceride-lowering effect of fenofibrate.
J. Lipid Res.
PUBLISHED: 06-04-2014
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The liver and the VLDL receptor (VLDLR) play major roles in TG and VLDL metabolism. However, the exact role of liver VLDLR is not well known because of the absence of or difficulty in detecting VLDLR in the liver. In this study, we demonstrate that fenofibrate, a PPAR? agonist and widely used TG-lowering drug, markedly upregulated hepatic VLDLR, which is essential for lowering TG. This study also shows that the distinct regulatory roles of PPAR? agonists on VLDLR in the liver and peripheral tissues including adipose tissues, heart, and skeletal muscles are due to the pattern of expression of PPAR?. The in vivo portion of our study demonstrated that oral fenofibrate robustly increased liver VLDLR expression levels in hyperlipidemic and diabetic mice and significantly reduced the increase in serum TG observed in wt mice after feeding with high-fat diet (HFD) but not in Vldlr(-/-) mice or Ppar?(-/-) mice. However, overexpression of mouse VLDLR in livers of Vldlr(-/-) mice significantly prevented the increase in serum TG induced by HFD. The in vitro portion of our study showed that fenofibrate upregulated VLDLR transcriptional activity through PPAR response element binding to the VLDLR promoter. The conclusions of our study provide a novel mechanism for the TG-lowering effects of fenofibrate in the treatment of dyslipidemia.
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Amniotic Fluid-Derived Stem Cells Demonstrated Cardiogenic Potential in Indirect Co-culture with Human Cardiac Cells.
Ann Biomed Eng
PUBLISHED: 05-23-2014
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Amniotic fluid-derived stem cells (AFSC) have been shown to be broadly multipotent and non-tumorogenic. Previous studies of direct mixing of AFSC and neonatal rat ventricle myocytes indicated evidence of AFSC cardiogenesis. In this study, we examined human AFSC cardiogenic potential in indirect co-culture with human cardiac cells in conditions that eliminated the possibility of cell fusion. Human AFSC in contact with human cardiac cells showed expression of cardiac troponin T (cTnT) in immunohistochemistry, and no evidence of cell fusion was found through fluorescent in situ hybridization. When indirectly co-cultured with cardiac cells, human AFSC in contact with cardiac cells across a thin porous membrane showed a statistically significant increase in cTnT expression compared to non-contact conditions but lacked upregulation of calcium modulating proteins and did not have functional or morphological characteristics of mature cardiomyocytes. This suggests that contact is a necessary but not sufficient condition for AFSC cardiac differentiation in co-culture with cardiac cells.
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Chronic alcohol consumption from adolescence-to-adulthood in mice--hypothalamic gene expression changes in the dilated cardiomyopathy signaling pathway.
BMC Neurosci
PUBLISHED: 04-23-2014
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Adolescence is a developmental stage vulnerable to alcohol drinking-related problems and the onset of alcoholism. Hypothalamus is a key brain region for food and water intake regulation, and is one of the alcohol-sensitive brain regions. However, it is not known what would be the alcohol effect on hypothalamus following adolescent alcohol intake, chronically over the adolescent development, at moderate levels.
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Self-Assembly of Conjugated Units Using Metal-Terpyridine Coordination.
Macromol Rapid Commun
PUBLISHED: 04-16-2014
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Due to their inherently dynamic natures and fascinating photoluminescent/photoelectronic properties, coordination compounds of metal ions and conjugated terpyridine ligands have attracted considerable attention as functional materials for a variety of potential applications. In this feature article, a summary of recent work toward the development of one- (1D), two- (2D), and three-dimensional (3D) supramolecular polymers, networks, and metallomacrocycles based on zinc metal ion coordination of conjugated units bearing terpyridine ligands is presented, and it is shown how it fits within the overall framework of work in this field. Here, a sequential study from terpyridines as basic building blocks to their zinc-coordinated supramolecular 1D polymers, 2D macrocycles, and 2D and 3D networks is developed. These networks are compared with respect to their thermal stabilities, molecular organization, and linear and nonlinear optical properties. This work opens new prospects for the development of supramolecular chemistry of terpyridines and other transition metal ions, and also their application in future optoelectronic devices.
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Knockdown of CXCR7 inhibits proliferation and invasion of osteosarcoma cells through inhibition of the PI3K/Akt and ?-arrestin pathways.
Oncol. Rep.
PUBLISHED: 03-31-2014
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CXC chemokine receptor 7 (CXCR7) has been implicated in tumor development and metastasis in multiple malignancies. Yet, the function and molecular mechanisms of CXCR7 in human osteosarcoma (OS) are still unclear. The aim of the present study was to investigate the role of CXCR7 in human OS. The expression of CXCR7 was assessed by immunohistochemical assay using a tissue microarray procedure in 45 cases of OS tissues. A loss?of-function approach was used to observe the effects of lentiviral vector-mediated CXCR7 siRNA (Lv-siCXCR7) on biological behaviors including proliferative activities and invasive potential, as indicated by MTT and Transwell assays in OS (MG-63 and U-2 OS) cells. The results showed that the expression of CXCR7 protein in OS tissues was significantly increased compared to that in adjacent non-cancerous tissues (68.9 vs. 53.3%, P=0.033), and was correlated with the distant metastasis of the tumors (P=0.004). Knockdown of CXCR7 suppressed proliferation and invasion of OS cells through decreased expression of PI3K, AKT, ?-arrestin, proliferating cell nuclear antigen (PCNA), and matrix metalloproteinase-9 (MMP-9). In addition, the tumor volume in U-2 OS subcutaneous tumor models treated with Lv-siCXCR7 was significantly smaller than the tumor volume in the negative control group (P<0.01). Collectively, our findings indicate that upregulation of CXCR7 expression is correlated with distant metastasis of OS, while knockdown of CXCR7 blocks the development of OS cells through inhibition of the PI3K/AKT and ?-arrestin pathways, suggesting that CXCR7 may serve as a potential therapeutic target for the treatment of cancer.
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Identification of antihyperlipidemic constituents from the roots of Rubia yunnanensis Diels.
J Ethnopharmacol
PUBLISHED: 03-30-2014
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The roots of Rubia yunnanensis Diels (Rubiaceae) have been used as an alternative for Rubia cordifolia for the treatment of various diseases including cardiovascular disease and metabolic disease for a long history in traditional Chinese medicine. To evaluate antihyperlipidemic activity of the roots of Rubia. yunnanensis Diels and to identify active compounds from the active fraction.
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Physiologic and metabolic safety of butyrylcholinesterase gene therapy in mice.
Vaccine
PUBLISHED: 02-06-2014
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In continuing efforts to develop gene transfer of human butyrylcholinesterase (BChE) as therapy for cocaine addiction, we conducted wide-ranging studies of physiological and metabolic safety. For that purpose, mice were given injections of adeno-associated virus (AAV) vector or helper-dependent adenoviral (hdAD) vector encoding human or mouse BChE mutated for optimal cocaine hydrolysis. Age-matched controls received saline or AAV-luciferase control vector. At times when transduced BChE was abundant, physiologic and metabolic parameters in conscious animals were evaluated by non-invasive Echo-MRI and an automated "Comprehensive Laboratory Animal Monitoring System" (CLAMS). Despite high vector doses (up to 10(13) particles per mouse) and high levels of transgene protein in the plasma (?1500-fold above baseline), the CLAMS apparatus revealed no adverse physiologic or metabolic effects. Likewise, body composition determined by Echo-MRI, and glucose tolerance remained normal. A CLAMS study of vector-treated mice given 40 mg/kg cocaine showed none of the physiologic and metabolic fluctuations exhibited in controls. We conclude that neither the tested vectors nor great excesses of circulating BChE affect general physiology directly, while they protect mice from disturbance by cocaine. Hence, viral gene transfer of BChE appears benign and worth exploring as a therapy for cocaine abuse and possibly other disorders as well.
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Structural and electronic properties of uranium-encapsulated Au?? cage.
Sci Rep
PUBLISHED: 01-20-2014
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The structural properties of the uranium-encapsulated nano-cage U@Au14 are predicted using density functional theory. The presence of the uranium atom makes the Au14 structure more stable than the empty Au14-cage, with a triplet ground electronic state for U@Au14. Analysis of the electronic structure shows that the two frontier single-occupied molecular orbital electrons of U@Au14 mainly originate from the 5f shell of the U atom after charge transfer. Meanwhile, the bonding orbitals and charge population indicate that the designed U@Au14 nano-cage structure is stabilized by ionocovalent interactions. The current findings provide theoretical basis for future syntheses and further study of actinide doped gold nanoclusters, which might subsequently facilitate applications of such structure in radio-labeling, nanodrug carrier and other biomedical applications.
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Gene expression profiles associated with osteoblasts differentiated from bone marrow stromal cells.
Asian Pac J Trop Med
PUBLISHED: 01-15-2014
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To study the changes of gene expression profiles associated with osteoblasts differentiated from rat bone marrow stromal cells in vitro by gene chip technique.
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miR-145 inhibits invasion of bladder cancer cells by targeting PAK1.
Urol. Oncol.
PUBLISHED: 01-02-2014
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MicroRNAs play important roles in cancer. In many cancers, miR-145 acts as a tumor suppressor, and it is down-regulated in bladder cancer. In the present study, we explored the modulation of oncogenic gene PAK1 by miR-145 in bladder cancer.
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A Functional TNFAIP2 3'-UTR rs8126 Genetic Polymorphism Contributes to Risk of Esophageal Squamous Cell Carcinoma.
PLoS ONE
PUBLISHED: 01-01-2014
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Accumulated evidences demonstrated that single nucleotide polymorphisms (SNPs) in mRNA 3'-untranslated region (3'-UTR) may impact microRNAs (miRNAs)-mediated expression regulation of oncogenes and tumor suppressors. There is a TNFAIP2 3'-UTR rs8126 T>C genetic variant which has been proved to be associated with head and neck cancer susceptibility. This SNP could disturb binding of miR-184 with TNFAIP2 mRNA and influence TNFAIP2 regulation. However, it is still unclear how this polymorphism is involved in development of esophageal squamous cell carcinoma (ESCC). Therefore, we hypothesized that the functional TNFAIP2 rs8126 SNP may affect TNFAIP2 expression and, thus, ESCC risk.
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Nanotechnology for the detection and kill of circulating tumor cells.
Nanoscale Res Lett
PUBLISHED: 01-01-2014
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Circulating tumor cells (CTCs) represent a surrogate biomarker of hematogenous metastases and thus could be considered as a 'liquid biopsy' which reveals metastasis in action. But it is absolutely a challenge to detect CTCs due to their extreme rarity. At present, the most common principle is to take advantage of the epithelial surface markers of CTCs which attach to a specific antibody. Antibody-magnetic nanobeads combine with the epithelial surface markers, and then the compound is processed by washing, separation, and detection. However, a proportion of CTC antigen expressions are down-regulated or lost in the process of epithelial-mesenchymal transition (EMT), and thus, this part of CTCs cannot be detected by classical detection methods such as CellSearch. To resolve this problem, some multiple-marker CTC detections have been developed rapidly. Additionally, nanotechnology is a promising approach to kill CTCs with high efficiency. Implantable nanotubes coated with apoptosis-promoting molecules improve the disease-free survival and overall survival. The review introduces some novel CTC detection techniques and therapeutic methods by virtue of nanotechnology to provide a better knowledge of the progress about CTC study.
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Oxaliplatin-based adjuvant chemotherapy without radiotherapy can improve the survival of locally-advanced rectal cancer.
PLoS ONE
PUBLISHED: 01-01-2014
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To assess the impact of oxaliplatin-containing adjuvant chemotherapy on the survival of patients with locally-advanced rectal cancer.
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Sleep disturbances and health-related quality of life in adults with steady-state bronchiectasis.
PLoS ONE
PUBLISHED: 01-01-2014
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Sleep disturbances are common in patients with chronic lung diseases, but little is known about the prevalence in patients with bronchiectasis. A cross sectional study was conducted to investigate the prevalence and determinants associated with sleep disturbances, and the correlation between sleep disturbances and quality of life (QoL) in adults with steady-state bronchiectasis.
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Content-based image retrieval using spatial layout information in brain tumor T1-weighted contrast-enhanced MR images.
PLoS ONE
PUBLISHED: 01-01-2014
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This study aims to develop content-based image retrieval (CBIR) system for the retrieval of T1-weighted contrast-enhanced MR (CE-MR) images of brain tumors. When a tumor region is fed to the CBIR system as a query, the system attempts to retrieve tumors of the same pathological category. The bag-of-visual-words (BoVW) model with partition learning is incorporated into the system to extract informative features for representing the image contents. Furthermore, a distance metric learning algorithm called the Rank Error-based Metric Learning (REML) is proposed to reduce the semantic gap between low-level visual features and high-level semantic concepts. The effectiveness of the proposed method is evaluated on a brain T1-weighted CE-MR dataset with three types of brain tumors (i.e., meningioma, glioma, and pituitary tumor). Using the BoVW model with partition learning, the mean average precision (mAP) of retrieval increases beyond 4.6% with the learned distance metrics compared with the spatial pyramid BoVW method. The distance metric learned by REML significantly outperforms three other existing distance metric learning methods in terms of mAP. The mAP of the CBIR system is as high as 91.8% using the proposed method, and the precision can reach 93.1% when the top 10 images are returned by the system. These preliminary results demonstrate that the proposed method is effective and feasible for the retrieval of brain tumors in T1-weighted CE-MR Images.
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[Coronary atherosclerosis lesion features in coronary artery disease patients complicating with metabolic syndrome].
Zhonghua Xin Xue Guan Bing Za Zhi
PUBLISHED: 12-28-2013
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Purpose To compare coronary plaque burden, composition, distribution and the degree of coronary artery stenosis in invasive coronary angiography (ICA) diagnosed coronary artery disease (CAD) patients with or without metabolic syndrome (MetS).
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Metabolic syndrome and coronary artery calcification: a community-based natural population study.
Chin. Med. J.
PUBLISHED: 12-18-2013
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Little is known about the influence of metabolic syndrome (MetS) on coronary artery calcification (CAC) in China. In this article, we aimed to explore the distribution of CAC in populations with and without MetS, and estimate the influence of MetS and its components on CAC in a community-based population of Beijing.
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Prostate Segmentation in CT Images via Spatial-Constrained Transductive Lasso.
Proc IEEE Comput Soc Conf Comput Vis Pattern Recognit
PUBLISHED: 12-17-2013
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Accurate prostate segmentation in CT images is a significant yet challenging task for image guided radiotherapy. In this paper, a novel semi-automated prostate segmentation method is presented. Specifically, to segment the prostate in the current treatment image, the physician first takes a few seconds to manually specify the first and last slices of the prostate in the image space. Then, the prostate is segmented automatically by the proposed two steps: (i) The first step of prostate-likelihood estimation to predict the prostate likelihood for each voxel in the current treatment image, aiming to generate the 3-D prostate-likelihood map by the proposed Spatial-COnstrained Transductive LassO (SCOTO); (ii) The second step of multi-atlases based label fusion to generate the final segmentation result by using the prostate shape information obtained from the planning and previous treatment images. The experimental result shows that the proposed method outperforms several state-of-the-art methods on prostate segmentation in a real prostate CT dataset, consisting of 24 patients with 330 images. Moreover, it is also clinically feasible since our method just requires the physician to spend a few seconds on manual specification of the first and last slices of the prostate.
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Edge-controlled growth and kinetics of single-crystal graphene domains by chemical vapor deposition.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 12-02-2013
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The controlled growth of large-area, high-quality, single-crystal graphene is highly desired for applications in electronics and optoelectronics; however, the production of this material remains challenging because the atomistic mechanism that governs graphene growth is not well understood. The edges of graphene, which are the sites at which carbon accumulates in the two-dimensional honeycomb lattice, influence many properties, including the electronic properties and chemical reactivity of graphene, and they are expected to significantly influence its growth. We demonstrate the growth of single-crystal graphene domains with controlled edges that range from zigzag to armchair orientations via growth-etching-regrowth in a chemical vapor deposition process. We have observed that both the growth and the etching rates of a single-crystal graphene domain increase linearly with the slanted angle of its edges from 0° to ?19° and that the rates for an armchair edge are faster than those for a zigzag edge. Such edge-structure-dependent growth/etching kinetics of graphene can be well explained at the atomic level based on the concentrations of the kinks on various edges and allow the evolution and control of the edge and morphology in single-crystal graphene following the classical kinetic Wulff construction theory. Using these findings, we propose several strategies for the fabrication of wafer-sized, high-quality, single-crystal graphene.
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Concise Synthesis and Biological Evaluation of 2-Aroyl-5-Amino Benzo[b]thiophene Derivatives As a Novel Class of Potent Antimitotic Agents.
J. Med. Chem.
PUBLISHED: 11-11-2013
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The biological importance of microtubules make them an interesting target for the synthesis of antitumor agents. The 2-(3,4,5-trimethoxybenzoyl)-5-aminobenzo[b]thiophene moiety was identified as a novel scaffold for the preparation of potent inhibitors of microtubule polymerization acting through the colchicine site of tubulin. The position of the methoxy group on the benzo[b]thiophene was important for maximal antiproliferative activity. Structure-activity relationship analysis established that the best activities were obtained with amino and methoxy groups placed at the C-5 and C-7 positions, respectively. Compounds 3c-e showed more potent inhibition of tubulin polymerization than combretastatin A-4 and strong binding to the colchicine site. These compounds also demonstrated substantial antiproliferative activity, with IC50 values ranging from 2.6 to 18 nM in a variety of cancer cell lines. Importantly, compound 3c (50 mg/kg), significantly inhibited the growth of the human osteosarcoma MNNG/HOS xenograft in nude mice.
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Human Herpesvirus 8 Interleukin-6 Contributes to Primary Effusion Lymphoma Cell Viability via Suppression of Proapoptotic Cathepsin D, a Cointeraction Partner of Vitamin K Epoxide Reductase Complex Subunit 1 Variant 2.
J. Virol.
PUBLISHED: 11-06-2013
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Human herpesvirus 8 (HHV-8) interleukin-6 (vIL-6) promotes cell proliferation and survival and is proangiogenic, implicating it as a contributor to virus-associated Kaposis sarcoma, primary effusion lymphoma (PEL), and multicentric Castlemans disease. Although predominantly lytically expressed, vIL-6 is also produced at low, functional levels during latency in PEL cells. Unlike other IL-6 cytokines, vIL-6 is secreted very inefficiently and localizes in the endoplasmic reticulum (ER). ER-localized vIL-6 supports PEL cell proliferation and survival, mediated in part through its interaction with the largely uncharacterized ER-resident protein vitamin K epoxide reductase complex subunit 1 variant 2 (VKORC1v2). Here, we report that the ER-transiting and functionally mitogenic secreted proenzyme (pCatD) form of cathepsin D (mature CatD), a proapoptotic lysosomal aspartate protease, is an interaction partner of VKORC1v2 and that vIL-6 promotes this interaction. Depletion of vIL-6 in PEL cells increased levels of the catalytically active, proteolytically cleaved form of CatD, corresponding with decreased PEL cell viability. Ectopic expression of CatD in PEL cells induced apoptosis, suggesting that CatD suppression by vIL-6 is biologically significant. In the context of high-density culture or reactivation of HHV-8 lytic replication in PEL cells, CatD depletion substantially reduced stress-induced apoptosis and increased virus production. In contrast, CatD overexpression, vIL-6 depletion, and peptide-mediated disruption of vIL-6-VKORC1v2 interaction inhibited replication and cell survival. Combined, our data identify pCatD as an interaction partner of VKORC1v2, demonstrate a role of vIL-6 in CatD suppression via VKORC1v2 in PEL cells, and identify a biologically significant mechanism of vIL-6 prosurvival and proreplication activities via VKORC1v2.
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Pax9 regulates a molecular network involving Bmp4, Fgf10, Shh signaling and the Osr2 transcription factor to control palate morphogenesis.
Development
PUBLISHED: 10-30-2013
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Cleft palate is one of the most common birth defects in humans. Whereas gene knockout studies in mice have shown that both the Osr2 and Pax9 transcription factors are essential regulators of palatogenesis, little is known about the molecular mechanisms involving these transcription factors in palate development. We report here that Pax9 plays a crucial role in patterning the anterior-posterior axis and outgrowth of the developing palatal shelves. We found that tissue-specific deletion of Pax9 in the palatal mesenchyme affected Shh expression in palatal epithelial cells, indicating that Pax9 plays a crucial role in the mesenchyme-epithelium interactions during palate development. We found that expression of the Bmp4, Fgf10, Msx1 and Osr2 genes is significantly downregulated in the developing palatal mesenchyme in Pax9 mutant embryos. Remarkably, restoration of Osr2 expression in the early palatal mesenchyme through a Pax9(Osr2KI) allele rescued posterior palate morphogenesis in the absence of Pax9 protein function. Our data indicate that Pax9 regulates a molecular network involving the Bmp4, Fgf10, Shh and Osr2 pathways to control palatal shelf patterning and morphogenesis.
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[Relation between uric acid and coronary artery calcification:a community-based cross-sectional survey among Beijing natural population].
Zhonghua Liu Xing Bing Xue Za Zhi
PUBLISHED: 10-16-2013
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To investigate the influence of uric acid on coronary artery calcification in the natural population in Beijing.
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Iterative image reconstruction for ultra-low-dose CT with a combined low-mAs and sparse-view protocol.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 10-11-2013
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Ultra-low-dose x-ray computed tomography (CT) imaging is needed in CT fields. Through a scan protocol by lowering the milliampere-seconds (mAs) and reducing the number of projections per rotation around the body, we can realize low-dose CT imaging. However, the resulting noisy and insufficient measurements will unavoidably cause the degradation of desired-image. To solve this problem, iterative image reconstruction is a promising choice for achieving high-quality image with a low-dose scan. In this study, we are focusing on ultra-low-dose CT image reconstruction by using penalized weighted least-square (PWLS) criteria with a combined low-mAs and sparse-view protocol. Specifically, the sinogram data acquired with a combined low-mAs and sparse-view protocol is first restored by using a PWLS based sinogram restoration method. Then, the restored sinogram data is hereafter used to reconstruct image by using a PWLS based total variation (PWLS-TV) method. Qualitative and quantitative evaluations by simulations were carried out to validate the present method.
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Rapamycin prevents drug seeking via disrupting reconsolidation of reward memory in rats.
Int. J. Neuropsychopharmacol.
PUBLISHED: 10-08-2013
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The maladaptive drug memory developed between the drug-rewarding effect and environmental cues contributes to difficulty in preventing drug relapse. Established reward memories can be disrupted by pharmacologic interventions following their reactivation. Rapamycin, an inhibitor of mammalian target of rapamycin (mTOR) kinase, has been proved to be involved in various memory consolidation. However, it is less well characterized in drug memory reconsolidation. Using a conditioned place preference (CPP) procedure, we examined the effects of systemically administered rapamycin on reconsolidation of drug memory in rats. We found that systemically administered rapamycin (0.1 or 10 mg/kg, i.p.) after re-exposure to drug-paired environment, dose dependently decreased the expression of CPP 1 d later, and the effect lasted for up to 14 d and could not be reversed by a priming injection of morphine. The effect of rapamycin on morphine-associated memory was specific to drug-paired context, and rapamycin had no effect on subsequent CPP expression when rats were exposed to saline-paired context or homecage. These results indicated that systemic administration of rapamycin after memory reactivation can persistently inhibit the drug seeking behaviour via disruption of morphine memory reconsolidation in rats. Additionally, the effect of rapamycin on memory reconsolidation was reproduced in cocaine CPP and alcohol CPP. Furthermore, rapamycin did not induce conditioned place aversion and had no effect on locomotor activity and anxiety behaviour. These findings suggest that rapamycin could erase the acquired drug CPP in rats, and that mTOR activity plays an important role in drug reconsolidation and is required for drug relapse.
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Effect of miR27a on proliferation and invasion in colonic cancer cells.
Asian Pac. J. Cancer Prev.
PUBLISHED: 10-03-2013
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The aim of this study was to detect the expression of miR196a, miR146a, miR27a and miR200a in patients with colon cancer, and investigate the effect of miR27a expression on proliferation and invasion in colonic cancer cells. RT-PCR was employed to detect the expression levels in colon cancers. Then, colon cancer cells were cultured and transfected with 100 nM of miR27a mimics (80 nmol/L) or 80 nM miR27a inhibitors (80 nmol/L) in 24-well plates. Proliferation and invasion of colonic cancer cells were then determined by CCK-8 and Transwell assays, respectively. Our data showed miR27a to be high-expressed in patients with colon cancer. In addition, proliferation and invasion in the miR27a mimic group were significantly higher than in the control group and negative group (P<0.05), while, proliferation and invasion in the miR27a inhibitor group were obviously lowered (P<0.05). In conclusion, high expression of miR27a may play an important role in enhancing proliferation and invasion of colon cancer cells.
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Signatures in vibrational and UV-visible absorption spectra for identifying cyclic hydrocarbons by graphene fragments.
Nanoscale
PUBLISHED: 09-24-2013
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To promote possible applications of graphene in molecular identification based on stacking effects, in particular in recognizing aromatic amino acids and even sequencing nucleobases in life sciences, we comprehensively study the interaction between graphene segments and different cyclic organic hydrocarbons including benzene (C6H6), cyclohexane (C6H12), benzyne (C6H4), cyclohexene (C6H10), 1,3-cyclohexadiene (C6H8(1)) and 1,4-cyclohexadiene (C6H8(2)), using the density-functional tight-binding (DFTB) method. Interestingly, we find obviously different characteristics in Raman vibrational and ultraviolet visible absorption spectra of the small molecules adsorbed on the graphene sheet. Specifically, we find that both spectra involve clearly different characteristic peaks, belonging to the different small molecules upon adsorption, with the ones of ionized molecules being more substantial. Further analysis shows that the adsorptions are almost all due to the presence of dispersion energy in neutral cases and involve charge transfer from the graphene to the small molecules. In contrast, the main binding force in the ionic adsorption systems is the electronic interaction. The results present clear signatures that can be used to recognize different kinds of aromatic hydrocarbon rings on graphene sheets. We expect that our findings will be helpful for designing molecular recognition devices using graphene.
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High specific detection and near-infrared photothermal therapy of lung cancer cells with high SERS active aptamer-silver-gold shell-core nanostructures.
Analyst
PUBLISHED: 09-17-2013
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Lung cancer is the leading cause of cancer death worldwide. Its early detection is of paramount importance for diagnosis, classification, treatment, and improvement of survivorship. However, current methods are not sensitive enough to detect lung cancer in its nascent stage. We reported an aptamer-Ag-Au shell-core nanostructure-based surface-enhanced Raman scattering (SERS) assay for sensitive and specific detection, and near-infrared (NIR) photothermal therapy of lung adenocarcinoma cells (A549 cells). The nanostructures target the cells with high affinity and specificity via the specific interaction between the aptamer (a 45-base oligonucleotide) and the cell, and distinguish A549 cells from other types of cancer cells (HeLa and MCF-7 cells) and subtypes of lung cancer cells (NCI-H157, NCI-H520, NCI-H1299, and NCI-H446 cells). The nanostructures have a high capability to absorb NIR irradiation and are able to perform photothermal therapy of the cells at a very low irradiation power density (0.20 W cm(-2)) without destroying the healthy cells and the surrounding normal tissues. In addition, the nanostructures exhibit a high SERS activity. Based on the SERS signal of the labeled Raman reporter (Rh6G molecules), we can specifically detect A549 cells at a very low abundance (~10 cells per mL) and monitor the therapy process of the cancer cells. Therefore, this nanostructure-based SERS assay has great potential in specific recognition, sensitive detection, and effective photothermal therapy of lung cancer.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.