Hefei National Laboratory for Physical science

Science, China

Hefei National Laboratory for Physical science

Science, China
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Ma N.,Hefei National Laboratory for Physical science | Liu Y.,Anhui Provincial Hospital | Li N.,Hefei National Laboratory for Physical science | Wang C.-X.,Anhui Provincial Hospital | And 6 more authors.
NeuroImage | Year: 2010

It is widely accepted that addictive drug use is related to abnormal functional organization in the user's brain. The present study aimed to identify this type of abnormality within the brain networks implicated in addiction by resting-state functional connectivity measured with functional magnetic resonance imaging (fMRI). With fMRI data acquired during resting state from 14 chronic heroin users (12 of whom were being treated with methadone) and 13 non-addicted controls, we investigated the addiction related alteration in functional connectivity between the regions in the circuits implicated in addiction with seed-based correlation analysis. Compared with controls, chronic heroin users showed increased functional connectivity between nucleus accumbens and ventral/rostral anterior cingulate cortex (ACC), between nucleus accumbens and orbital frontal cortex (OFC), and between amygdala and OFC and reduced functional connectivity between prefrontal cortex and OFC and between prefrontal cortex and ACC. These observations of altered resting-state functional connectivity suggested abnormal functional organization in the addicted brain and may provide additional evidence supporting the theory of addiction that emphasizes enhanced salience value of a drug and its related cues but weakened cognitive control in the addictive state. © 2009 Elsevier Inc. All rights reserved.

Li G.,Hefei University of Technology | Wu X.,Hefei University of Technology | Qian W.,Hefei University of Technology | Qian W.,Hefei National Laboratory for Physical science | And 23 more authors.
Cell Research | Year: 2016

MicroRNAs (miRNAs) typically bind to unstructured miRNA-binding sites in target RNAs, leading to a mutual repression of expression. Here, we report that miR-1254 interacts with structured elements in cell cycle and apoptosis regulator 1 (CCAR1) 5′ untranslated region (UTR) and this interaction enhances the stability of both molecules. miR-1254 can also act as a repressor when binding to unstructured sites in its targets. Interestingly, structured miR-1254-targeting sites act as both a functional RNA motif-sensing unit, and an independent RNA functional unit that enhances miR-1254 expression. Artificially designed miRNA enhancers, termed "miRancers", can stabilize and enhance the activity of miRNAs of interest. We further demonstrate that CCAR1 5′ UTR as a natural miRancer of endogenous miR-1254 re-sensitizes tamoxifen-resistant breast cancer cells to tamoxifen. Thus, our study presents a novel model of miRNA function, wherein highly structured miRancer-like motif-containing RNA fragments or miRancer molecules specifically interact with miRNAs, leading to reciprocal stabilization. © 2016 IBCB, SIBS, CAS All rights reserved.

Li X.,Hefei National Laboratory for Physical science | Huang H.,Massachusetts General Hospital | Huang H.,The Broad Institute of MIT and Harvard | Zhu T.,Hefei National Laboratory for Physical science
BioMed Research International | Year: 2014

Transwell Boyden chamber based migration/invasion assay is a simple and extensively used approach for the characterization of cell motility in vitro. Cell motility is quantified by counting the number of cells that pass through the filter membrane. The counting is usually performed manually, which is laborious and error prone. We have therefore developed CELLCOUNTER, an application that is capable of recognizing and counting the total number of cells through an intuitive graphical user interface. The counting can be performed in batch, and the counting results can be visualized and further curated manually. CELLCOUNTER will be helpful in streamlining the experimental process and improving the reliability of the data acquisition. © 2014 Xiaoni Li et al.

Lu X.,Hefei National Laboratory for Physical science | Lu X.,Tsinghua University | Xiao B.,Hefei National Laboratory for Physical science | Zhang Z.,Hefei National Laboratory for Physical science | And 5 more authors.
Nature Communications | Year: 2016

New carbon-carbon bond formation reactions expand our horizon of retrosynthetic analysis for the synthesis of complex organic molecules. Although many methods are now available for the formation of C(sp2)-C(sp3) and C(sp3)-C(sp3) bonds via transition metal-catalyzed cross-coupling of alkyl organometallic reagents, direct use of readily available olefins in a formal fashion of hydrocarbonation to make C(sp2)-C(sp3) and C(sp3)-C(sp3) bonds remains to be developed. Here we report the discovery of a general process for the intermolecular reductive coupling of unactivated olefins with alkyl or aryl electrophiles under the promotion of a simple nickel catalyst system. This new reaction presents a conceptually unique and practical strategy for the construction of C(sp2)-C(sp3) and C(sp3)-C(sp3) bonds without using any organometallic reagent. The reductive olefin hydrocarbonation also exhibits excellent compatibility with varieties of synthetically important functional groups and therefore, provides a straightforward approach for modification of complex organic molecules containing olefin groups.

Cong H.-P.,Hefei University of Technology | Cong H.-P.,Hefei National Laboratory for Physical science | Qiu J.-H.,Hefei National Laboratory for Physical science | Yu S.-H.,Hefei National Laboratory for Physical science
Small | Year: 2015

Synthetic stimuli-sensitive hydrogel as an important kind of soft intelligent materials has attracted academic and industrial attention as well as its biocompatibility with a high content of water, similar to biological tissues. Under external stimulus, including temperature,[1,2] light[3,4] and pH,[5,6] such hydrogels can exhibit the interesting discontinuous and reversible volume phase transition between a swollen state and a collapsed state, which provide promising potentials in the wide application fi elds of drug release, tissue engineering, sensor, actuator, etc. Among them, the environmentally-thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) hydrogel has been widely investigated,[2,7,8] which shows attractive volume change through absorbing or excluding water attributed from the reversible coil-to-globule transition of macromolecular chains at the well-known lower critical solution temperature (LCST).[9] However, conventional polymer hydrogel with the organic cross-linker often behaves poor mechanical performance and weak resistance to crack propagation because of the lack of an effi cient mechanism for crack energy dissipation, which severely limits its practical applications. Recent work reveals that double-network hydrogel[10,11] with fi rst highlycrosslinked network and second loosely-crosslinked network and nanocomposite hydrogel[12-14] with nano-object as the large cross-linker are the typical models to achieve elastic hydrogel with tough mechanical strength. Very lately, we have reported a kind of polymer/graphene oxide (GO) composite hydrogel with robust and superstretchable mechanical behavior based on a newly-proposed double-network mechanism combined with nanocomposite concept,[15,16] triggered by Ca2+ coordination-induced GO network and covalently crosslinked polymer network which are intertwined by hydrogen bonds between oxygenate groups of GO sheets and the amino groups of polymer chains. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liang Z.,Hefei National Laboratory for Physical science | Zhou H.,Anhui University of Science and Technology | He Z.,Hefei National Laboratory for Physical science | Zheng H.,Anhui University of Science and Technology | And 2 more authors.
Nucleic Acids Research | Year: 2011

MicroRNAs (miRNAs) are critical regulators in the complex cellular networks. The mirAct web server (http://sysbio.ustc.edu.cn/software/mirAct) is a tool designed to investigate miRNA activity based on gene-expression data by using the negative regulation relationship between miRNAs and their target genes. mirAct supports multiple-class data and enables clustering analysis based on computationally determined miRNA activity. Here, we describe the framework of mirAct, demonstrate its performance by comparing with other similar programs and exemplify its applications using case studies. © 2011 The Author(s).

Fang H.,Anhui University of Science and Technology | Fang H.,Hefei National Laboratory for Physical science | Du X.,Anhui University of Science and Technology | Du X.,Hefei National Laboratory for Physical science | And 4 more authors.
Neuroendocrinology Letters | Year: 2011

OBJECTIVE: The effect of SUMO on the promoter activity and mRNA expression of BACE gene was investigated to find the connection between sumoylation and APP processing. METHODS: The BACE promoter activity was measured by reporter gene analysis and BACE mRNA level was investigated using real-time RT-PCR method. RESULTS: BACE gene promoter activity was inhibited by the over-expression of SUMO proteins and was blocked by disrupting the SP1 site. Endogenous BACE mRNA level was also negatively regulated by the induction of SUMO proteins. Using a specific inhitor of SP1, BACE promoter activity was coordinately inhibited. CONCLUSIONS: SUMO negatively regulates the BACE expression and SP1 is involved in the process. ©2011 Neuroendocrinology Letters.

Hou S.,Anhui University of Science and Technology | Ge K.,Anhui University of Science and Technology | Zheng X.,Anhui University of Science and Technology | Wei H.,Anhui University of Science and Technology | And 5 more authors.
Journal of Biological Chemistry | Year: 2014

Background: CD226 is an activating receptor on NK cells that mediates NK cell cytotoxicity. Results: The first extracellular domain of CD226 (CD226-ECD1) mediates NK cell recognition, adhesion, immune synapse formation, and cytotoxicity against target cells. Conclusion: CD226-ECD1 retains almost all functions of the full-length CD226 protein. Significance: The conclusion is helpful to understand the mechanism by which CD226 recognizes its ligands. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Wu Z.,Hefei National Laboratory for Physical science | Wu Z.,CAS Hefei Key Laboratory of Materials for Energy Conversion | Wu Z.,Hefei University of Technology | Ma Y.,Hefei University of Technology | And 15 more authors.
Journal of Physical Chemistry C | Year: 2012

The adsorption and surface reaction of NO 2 on a stepped Au(997) surface were investigated by temperature-programmed desorption, X-ray photoelectron spectroscopy, and ultraviolet photoelectron spectroscopy. At low NO 2 exposures, NO 2 chemisorbs molecularly and reversibly on the Au(997) surface at 130 K, but low-coordinated Au atoms on the (111) step sites exhibit enhanced reactivity. NO 2(a) chemisorbed on the (111) step sites is thermally more stable than that chemisorbed on the (111) terrace sites. At large NO 2 exposures, an amorphous physisorbed N 2O 4 multilayer forms at 130 K. Subsequent heating causes the isomerization of the physisorbed N 2O 4 multilayer (O 2N-NO 2) to nitrite-N 2O 4 (ONO-NO 2) and the subsequent transformation of nitrite-N 2O 4 into nitrosonium nitrate (NO +NO 3 -) that further decomposes into NO(g) and NO 2(g) at elevated temperatures, forming O(a) on the surface. These surface reactions could be utilized to prepare oxygen adatoms on inert Au surfaces under ultrahigh vacuum conditions. Our results broaden the fundamental understanding of the interaction between small molecules and Au surfaces. © 2012 American Chemical Society.

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