bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological Change of Cell Membrane by Interaction with Domain‐Swapped Cytochrome c Oligomers
Authors: Junedi Sendy , Yasuhara Kazuma , Nagao Satoshi , Kikuchi Jun‐ichi , Hirota Shun 
Published: January 2014

AbstractMonomeric cyt c has been reported to bind to the mitochondrial membrane by electrostatic and hydrophobic interactions with anionic phospholipids. We have previously shown that domain‐swapped oligomeric cyt c retains the secondary structure of the monomer, and its surface possesses a larger area and more charges compared to the monomer. However, the effect of oligomerization of cyt c on cells has yet to be revealed. Herein, we investigated the interaction of oligomeric cyt c with anionic phospholipid‐containing vesicles and the outer membrane of HeLa cells. Oligomeric cyt c interacted more strongly than monomeric cyt c with anionic phospholipid‐containing vesicles and the outer membrane of HeLa cells. Oligomeric cyt c induced lateral phase separation of lipids in LUVs and GUVs, thereby leading to membrane disruption, whereas monomeric cyt c did not. Morphological changes in HeLa cells resulted from interaction with oligomeric cyt c, but little from interaction with the monomer. These results show that domain‐swapped oligomeric proteins might exhibit properties different to those of monomer in cell systems.
Identification of Fluorinases from Streptomyces sp MA37, Norcardia brasiliensis, and Actinoplanes sp N902‐109 by Genome Mining
Authors: Deng Hai , Ma Long , Bandaranayaka Nouchali , Qin Zhiwei , Mann Greg , Kyeremeh Kwaku , Yu Yi , Shepherd Thomas , Naismith James H. , O'Hagan David 
Published: January 2014

AbstractThe fluorinase is an enzyme that catalyses the combination of S‐adenosyl‐L‐methionine (SAM) and a fluoride ion to generate 5′‐fluorodeoxy adenosine (FDA) and L‐methionine through a nucleophilic substitution reaction with a fluoride ion as the nucleophile. It is the only native fluorination enzyme that has been characterised. The fluorinase was isolated in 2002 from Streptomyces cattleya, and, to date, this has been the only source of the fluorinase enzyme. Herein, we report three new fluorinase isolates that have been identified by genome mining. The novel fluorinases from Streptomyces sp. MA37, Nocardia brasiliensis, and an Actinoplanes sp. have high homology (80–87 % identity) to the original S. cattleya enzyme. They all possess a characteristic 21‐residue loop. The three newly identified genes were overexpressed in E. coli and shown to be fluorination enzymes. An X‐ray crystallographic study of the Streptomyces sp. MA37 enzyme demonstrated that it is almost identical in structure to the original fluorinase. Culturing of the Streptomyces sp. MA37 strain demonstrated that it not only also elaborates the fluorometabolites, fluoroacetate and 4‐fluorothreonine, similar to S. cattleya, but this strain also produces a range of unidentified fluorometabolites. These are the first new fluorinases to be reported since the first isolate, over a decade ago, and their identification extends the range of fluorination genes available for fluorination biotechnology.
A novel estrogen receptor GPER mediates proliferation induced by 17β‐estradiol and selective GPER agonist G‐1 in estrogen receptor α (ERα)‐negative ovarian cancer cells
Authors: Liu Huidi , Yan Yan , Wen Haixia , Jiang Xueli , Cao Xuefeng , Zhang Guangmei , Liu Guoyi 
Published: January 2014

AbstractG protein‐coupled estrogen receptor (GPER) is recently identified as a membrane‐associated estrogen receptor that mediates non‐genomic effects of estrogen. Our previous immunohistochemistry study found an association between GPER and the proliferation of epithelial ovarian cancer. However, the contributions and mechanisms of GPER in the proliferation of ovarian cancers are not clear. We have examined the role of GPER in estrogen receptor α (ERα)‐negative/GPER positive OVCAR5 ovarian cancer cell line. MTT assay was used to detect cell proliferation. BrdU incorporation assay was used to measure the cells in S‐phase. Protein expression of marker genes of proliferation, cell cycle and apoptosis were examined by Western blot. The results showed that 17β‐estradiol and selective GPER agonist G‐1 stimulated the proliferation of OVCAR5 cells and increased the cells in S‐phase. Both ligands upregulated the protein levels of c‐fos and cyclin D1. Small interfering RNA targeting GPER or G protein inhibitor pertussin toxin (PTX) inhibited basal cell proliferation and attenuated 17β‐estradiol‐ or G‐1‐induced cell proliferation. GPER mediated cell growth was also associated with the apoptosis of OVCAR5 cells. These findings suggest that GPER has an important function in the proliferation of ovarian cancer cells lacking ERα. GPER might be a promising therapeutic target in ovarian cancer.
Artesunate exerts an anti‐immunosuppressive effect on cervical cancer by inhibiting PGE2 production and Foxp3 expression
Authors: Zhang Li‐xin , Liu Zhi‐neng , Ye Jun , Sha Min , Qian Hua , Bu Xin‐hua , Luan Zheng‐yun , Xu Xin‐lan , Huang Ai‐hua , Yuan Dong‐lan , Wu Yi‐qun , Wang Xiao‐xiang , Wang Jia , Huang Jun‐xing , Ye Li‐hua 
Published: January 2014

AbstractArtesunate (ART), derived from a common traditional Chinese medicine, has beeen used an antimalarial for several years. In this study, the effect and mechanism of ART on anti‐human cervical cancer cells was examined. The level of prostaglandin E2 (PGE2) and the population of CD4+CD25+Foxp3 regulatory T cells (Treg) in peripheral blood were detected by flow cytometry. In vivo antitumor activity was investigated in mice with cervical cancer by the subcutaneous injection of various concentrations of ART. The concentrations of PGE2 in the supernatants of CaSki cells were measured using an ELISA kit. Cyclooxygenase‐2 (COX‐2) and Foxp3 expression were determined using quantitative polymerase chain reaction (qPCR) and western blot analysis. The effect of ART on the viability of CaSki and Hela cells was evaluated with a 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. It was identified that the level of PGE2 and the population of CD4+CD25+Foxp3 Treg cells in the peripheral blood were significantly higher in cervical cancer patients and mice with cervical cancer. ART was capable of inhibiting orthotopic tumor growth, which correlated with a decrease in the level of PGE2 and the percentage of Treg cells in mice with cervical cancer. Furthermore, ART decreased COX‐2 expression and the production of PGE2 in CaSki and Hela cells. Notably, the supernatants of CaSki cells treated with ART lowered the expression of Foxp3 in Jurkat T cells, which was capable of being reversed by exogenous PGE2. Our data revealed that ART may elicit an anti‐tumor effect against cervical cancer by inhibition of PGE2 production in CaSki and Hela cells, which resulted in the decrease of Foxp3 expression in T cells. Therefore, ART may be an effective drug for immunotherapy of cervical cancer.
Differentiation potential of menstrual blood‐ versus bone marrow‐stem cells into glial‐like cells
Authors: Azedi Fereshteh , Kazemnejad Somaieh , Zarnani Amir Hassan , Behzadi Gila , Vasei Mohammad , Khanmohammadi Manijeh , Khanjani Sayeh , Edalatkhah Haleh , Lakpour Niknam 
Published: January 2014

AbstractMenstrual blood is easily accessible, renewable, and inexpensive source of stem cells that have been interested for cell therapy of neurodegenerative diseases. In this study, we showed conversion of menstrual blood stem cells (MenSCs) into clonogenic neurosphere‐ like cells (NSCs), which can be differentiated into glial‐like cells. Moreover, differentiation potential of MenSCs into glial lineage was compared with bone marrow stem cells (BMSCs). Differentiation potential of individual converted NSCs derived from MenSCs or BMSCs into glial‐like cells was investigated using immunofluorescence staining and real‐time polymerase chain reaction.The fibroblastic morphology of both MenSCs and BMSCs was turned into NSCs shape during first step of differentiation. NSCs derived from both BMSCs and MenSCs expressed higher levels of Olig‐2 and Nestin markers compared to undifferentiated cells. The expression levels of myelin basic protein (MBP) mRNA up regulated only in BMSCs‐NSCs no in MenSCs‐NSCs. However, outgrowth of individual NSCs derived from both MenSCs and BMSCs into glial‐like cells led to significant up regulation of glial fibrillary acidic protein,Olig‐2 and MBP at mRNA and protein level accompanied with down regulation of Nestin protein.This is the first study demonstrating that MenSCs can be converted to NSCs with differentiation ability into glial‐like cells. Accumulative data show different expression pattern of glial markers in differentiated MenSCs compared to BMSCs. The comparable differentiation potential, more accessibility and no invasive technique for sample collection of MenSCs in comparison with BMSCs introduce MenSCs as an apt, consistent and safe alternative to BMSCs for cell therapy of neurodegenerative diseases.
3‐D structure, volume, and DNA content of erythrocyte nuclei of polyploid fish
Authors: Bytyutskyy Dmytro , Kholodnyy Vitaliy , Flajšhans Martin 
Published: January 2014

AbstractWe have explored the potential relationship between ploidy level, DNA content (pg DNA nucleus−1), and dimensional characteristics, such as volume (μm3), surface area (μm2), and 3‐D structure of erythrocyte nuclei in a series of fish ploidy level models using Feulgen image analysis densitometry, flow cytometry, and confocal laser scanning microscopy. The species were diploid tench (Tinca tinca) (2n), Cuban gar (Atractosteus tristoechus) (2n), triploid tench (3n), evolutionary tetraploid sterlet (Acipenser ruthenus) (4n), evolutionary octaploid Siberian sturgeon (A. baerii) (8n), triploid Siberian sturgeon exhibiting dodecaploidy (12n), evolutionary 12n shortnose sturgeon (A. brevirostrum), and experimentally obtained sturgeon hybrids that were tetraploid, hexaploid (6n), heptaploid (7n), octaploid, decaploid (10n), dodecaploid and/or tetradecaploid (14n). Increase in ploidy was accompanied by growth of the nucleus and an increase in the number of flattened ellipsoid nuclei with increased transverse diameter. The volume (Vvoxel) of erythrocyte nuclei, as the sum of voxels calculated from live cells, seems more accurate than volume (Vaxis) calculated from measuring the major and minor axis, especially at higher and odd ploidy levels. Data of absolute and relative DNA content were in agreement with previously published reports. Species of the same ploidy level, but differing in DNA content, had a similar mean erythrocyte nuclear volume (Vvoxel), as demonstrated in sterlet and a hybrid of sterlet and beluga (48.3 and 48.9 μm3, respectively), with a respective mean DNA content of 3.74 and 3.10 pg DNA nucleus−1. A similar relationship was found for the ploidy 6n, 10n, 12n. The surface‐to‐volume ratio decreased non‐linearly with increasing ploidy. The DNA in erythrocyte nuclei appeared to be more densely packed with increase in ploidy level.
Disordered Mesoporous TiO2−xNx+Nano‐Au: An Electronically Integrated Nanocomposite for Solar H2 Generation
Authors: Sivaranjani Kumarsrinivasan , RajaAmbal Sivaraman , Das Tanmay , Roy Kanak , Bhattacharyya Somnath , Gopinath Chinnakonda S. 
Published: January 2014

AbstractWe report on H2 generation by photocatalysis driven by simulated white light by electronically integrated Au nanoparticles with multifunctional, disordered mesoporous TiO2−xNx (Au‐NT) nanocomposites. Solar H2 generation (1.5 mmol h−1 g−1) from aqueous methanol has been demonstrated with Au‐NT nanocomposites. The water splitting activity of Au‐NT is attributed to the 21.1 ps lifetime of charge carriers observed from fluorescence lifetime measurements, which indicates a high electron‐injection efficiency from nano‐Au to the conduction band of TiO2, and hence charge separation as well as utilization. This is directly supported by the observation of a high photoluminescence emission intensity with Au‐NT that highlights the energy transfer from nano‐Au to TiO2. The p–n heterojunction observed between the Au (0 0 1) and TiO2 (1 0 1) facets helps towards the higher charge separation and their utilization. A low mesochannel depth (<10 nm) associated with disordered mesoporous TiO2−xNx helps the charge carriers to move towards the surface for redox reactions and hence charge utilization. Visible‐light absorption, as a result of the surface plasmon resonance of nano‐Au, is observed in a broad range between 500 and 750 nm, which helps in harvesting visible‐light photons. Finally, electronically integrated nano‐Au with TiO2−xNx in Au‐NT is evident from Raman and X‐ray photoelectron spectroscopy measurements. All of these factors help to achieve a high rate of H2 production. It is likely that a higher rate of H2 production than that reported here is feasible by strategically locating Au clusters in porous TiO2 to generate hot spots through electronic integration.
Phosphorus Electrodes in Sodium Cells: Small Volume Expansion by Sodiation and the Surface‐Stabilization Mechanism in Aprotic Solvent
Authors: Yabuuchi Naoaki , Matsuura Yuta , Ishikawa Toru , Kuze Satoru , Son Jin‐Young , Cui Yi‐Tao , Oji Hiroshi , Komaba Shinichi 
Published: January 2014

AbstractThe electrode performance of amorphous phosphorus in aprotic Na cells is examined. Amorphous phosphorus is electrochemically reduced in the Na cells with a three‐electron redox process, crystallizing into Na3P. NaP bonds in Na3P have high covalent characteristics. Therefore, the molar volume of Na in Na3P is anomalously small in comparison to other Na–metal alloys that have been used as negative electrode materials. The theoretical volumetric capacity, calculated at full volume expansion of amorphous phosphorus electrodes through sodiation, is expected to be 27 % larger than that of metallic sodium. However, experimentally, it is found that severe electrolyte decomposition results in insufficient reversibility of the electrode materials, owing to the highly reactive Na3P surface. Electrode reversibility is successfully improved by utilizing an electrolyte additive, fluoroethylene carbonate (FEC). The surface chemistry of phosphorus in the aprotic solvent with sodium salts is examined by hard/soft X‐ray photoelectron spectroscopy (PES). PES studies reveal that FEC effectively stabilizes the solid–electrolyte interphase (SEI), containing monovalent phosphorus species and sodium fluoride, and thus electrolyte decomposition is partly suppressed by the relatively stable SEI formed on the surface of phosphorus particles.
Organic Nanoparticles: Mechanism of Electron Transfer to Indigo Nanoparticles
Authors: Cheng Wei , Batchelor‐McAuley Christopher , Compton Richard G. 
Published: January 2014

AbstractOrganic nanoparticles are attracting many significant applications in bio‐imaging and nanomedicine. However, in comparison with intensive studies of metal and inorganic nanoparticles, the research of organic nanoparticles is still at a very early stage due to their complex physical and chemical properties. Most recently, there are increasingly significant interests in developing nano‐capacitors and nano‐scale energy storage and sensor devices based on organic materials. Herein, we report for the first time the kinetics and mechanism of electron transfer to individual organic nanoparticles, using indigo nanoparticles as a model system, via analysis of the charge transferred in the reduction of individual organic nanoparticles. We conclude the indigo nanoparticles display irreversible (slow) electron transfer kinetics and that the charge transfer is the rate‐determining step in the reductive dissolution of the nanoparticles; protonation and detachment of molecules from the nanoparticles occurs after this rate‐determining step. The transfer coefficient, α, of the electron transfer is found to be 0.25±0.05, whilst the rate constant (k0) is determined as the composite parameter ${k^0 \exp \left( {{{0.25F} \over {RT}}E_{\rm{f}}^{\rm{{\rm \theta} }} } \right)}$, where ${E_{\rm{f}}^{\rm{{\rm \theta} }} }$ is the formal potential, which is found to have the value of 1.7×10−8 m s−1. Given the high importance of the electron transfer mechanism for organic nanomaterials, this report may have great significance on future research of organic nanomaterials for diverse applications.
A General Route to Hollow Mesoporous Rare‐Earth Silicate Nanospheres as a Catalyst Support
Authors: Jin Renxi , Yang Yang , Zou Yongcun , Liu Xianchun , Xing Yan 
Published: January 2014

AbstractHollow mesoporous structures have recently aroused intense research interest owing to their unique structural features. Herein, an effective and precisely controlled synthesis of hollow rare‐earth silicate spheres with mesoporous shells is reported for the first time, produced by a simple hydrothermal method, using silica spheres as the silica precursors. The as‐prepared hollow rare‐earth silicate spheres have large specific surface area, high pore volume, and controllable structure parameters. The results demonstrate that the selection of the chelating reagent plays critical roles in forming the hollow mesoporous structures. In addition, a simple and low‐energy‐consuming approach to synthesize highly stable and dispersive gold nanoparticle–yttrium silicate (AuNPs/YSiO) hollow nanocomposites has also been developed. The reduction of 4‐nitrophenol with AuNPs/YSiO hollow nanocomposites as the catalyst has clearly demonstrated that the hollow rare‐earth silicate spheres are good carriers for Au nanoparticles. This strategy can be extended as a general approach to prepare multifunctional yolk–shell structures with diverse compositions and morphologies simply by replacing silica spheres with silica‐coated nanocomposites.
Vertically Oriented Silica Mesochannels as the Template for Electrodeposition of Polyaniline Nanostructures and Their Electrocatalytic and Electroanalytical Applications
Authors: Ding Longhua , Li Wanzhen , Wang Qiaohong , Sun Qinqin , He Yayun , Su Bin 
Published: January 2014

AbstractA mesoporous silica film (MSF) with vertically oriented mesochannels on a conductive substrate serves as a hard‐template for electrodeposition of polyaniline (PANI). The PANI nanostructures thus prepared are orderly confined in silica mesochannels, eventually producing a robust hybrid film. The film displays a good electrocatalytic activity toward oxidation of ascorbic acid, and can be used for potentiometric pH sensing with a Nernstian response.
meso‐Ester and Carboxylic Acid Substituted BODIPYs with Far‐Red and Near‐Infrared Emission for Bioimaging Applications
Authors: Ni Yong , Zeng Lintao , Kang Nam‐Young , Huang Kuo‐Wei , Wang Liang , Zeng Zebing , Chang Young‐Tae , Wu Jishan 
Published: January 2014

AbstractA series of meso‐ester‐substituted BODIPY derivatives 1–6 are synthesized and characterized. In particular, dyes functionalized with oligo(ethylene glycol) ether styryl or naphthalene vinylene groups at the α positions of the BODIPY core (3–6) become partially soluble in water, and their absorptions and emissions are located in the far‐red or near‐infrared region. Three synthetic approaches are attempted to access the meso‐carboxylic acid (COOH)‐substituted BODIPYs 7 and 8 from the meso‐ester‐substituted BODIPYs. Two feasible synthetic routes are developed successfully, including one short route with only three steps. The meso‐COOH‐substituted BODIPY 7 is completely soluble in pure water, and its fluorescence maximum reaches around 650 nm with a fluorescence quantum yield of up to 15 %. Time‐dependent density functional theory calculations are conducted to understand the structure–optical properties relationship, and it is revealed that the Stokes shift is dependent mainly on the geometric change from the ground state to the first excited singlet state. Furthermore, cell staining tests demonstrate that the meso‐ester‐substituted BODIPYs (1 and 3–6) and one of the meso‐COOH‐substituted BODIPYs (8) are very membrane‐permeable. These features make these meso‐ester‐ and meso‐COOH‐substituted BODIPY dyes attractive for bioimaging and biolabeling applications in living cells.
CuI/Pd0 Cooperative Dual Catalysis: Tunable Stereoselective Construction of Tetra‐Substituted Alkenes
Authors: Vercruysse Sébastien , Cornelissen Loïc , Nahra Fady , Collard Laurent , Riant Olivier 
Published: January 2014

AbstractThis paper describes a tunable and stereoselective dual catalytic system that uses copper and palladium reagents. This cooperative silylcupration and palladium‐catalyzed allylation readily affords trisubstituted alkenylsilanes. Fine‐tuning the reaction conditions allows selective access to one stereoisomer over the other. This new methodology tolerates different substituents on both coupling partners with high levels of stereoselectivity. The one‐pot reaction involving a CuI/Pd0 cooperative dual catalyst directly addresses the need to develop more time‐efficient and less‐wasteful synthetic pathways.
Lysine Deacetylase (KDAC) Regulatory Pathways: an Alternative Approach to Selective Modulation
Authors: Van Dyke Michael W. 
Published: January 2014

AbstractProtein lysine deacetylases (KDACs), including the classic Zn2+‐dependent histone deacetylases (HDACs) and the nicotinamide adenine dinucleotide (NAD+)‐requiring sirtuins, are enzymes that play critical roles in numerous biological processes, particularly the epigenetic regulation of global gene expression programs in response to internal and external cues. Dysregulation of KDACs is characteristic of several human diseases, including chronic metabolic, neurodegenerative, and cardiovascular diseases and many cancers. This has led to the development of KDAC modulators, two of which (HDAC inhibitors vorinostat and romidepsin) have been approved for the treatment of cutaneous T cell lymphoma. By their nature, existing KDAC modulators are relatively nonspecific, leading to pan‐KDAC changes and undesired side effects. Given that KDACs are regulated at many levels, including transcriptional, post‐translational, subcellular localization, and through their complexation with other proteins, it should be possible to affect specific KDAC activity through manipulation of endogenous signaling pathways. In this Minireview, we discuss our present knowledge of the cellular controls of KDAC activity and examples of their pharmacologic regulation.