bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tetrathiomolybdate inhibits mitochondrial complex IV and mediates degradation of hypoxia-inducible factor-1α in cancer cells
Authors: Kim Kyu Kwang , Abelman Sarah , Yano Naohiro , Ribeiro Jennifer R. , Singh Rakesh K. , Tipping Marla , Moore Richard G. 
Published: October 2015

AbstractHypoxia-inducible factor-1α (HIF-1α) is a transcription factor that triggers adaptive responses upon low oxygen conditions and plays a crucial role in cancer metabolism and therapy resistance. Tetrathiomolybdate (TM), a therapy option for copper overload disorder, has also been shown to be capable of limiting tumor angiogenesis, although its underlying mechanism remains unclear. Using ovarian and endometrial cancer cell lines, we observed that TM downregulates HIF-1α protein levels and HIF-transcriptional targets involved in tumor angiogenesis and glycolysis, but did not affect HIF-1α protein synthesis. TM-mediated HIF-1α downregulation was suppressed when HIF-prolyl hydroxylase activity was pharmacologically inhibited using deferoxamine or dimethyloxaloylglycine and also when the oxygen-dependent degradation domains of HIF-1α, which are responsible for the interaction with HIF-prolyl hydroxylase, were deleted. These findings suggest that TM causes HIF-1α downregulation in a HIF-prolyl hydroxylase-dependent manner. Our studies showed that TM inhibits the activity of the copper-dependent mitochondrial complex IV and reduces mitochondrial respiration, thereby possibly increasing oxygen availability, which is crucial for HIF-prolyl hydroxylase activity. Pimonidazole staining also showed that TM elevates oxygen tension in hypoxic cells. Our studies provide mechanistic evidence for TM-mediated HIF-1α regulation and suggest its therapeutic potential as a method of blocking angiogenesis in ovarian and endometrial tumors.
Fine particulate matter (PM2.5) in China at a city level
Authors: Zhang Yan-Lin , Cao Fang 
Published: October 2015

AbstractThis study presents one of the first long term datasets including a statistical summary of PM2.5 concentrations obtained from one-year monitoring in 190 cities in China. We found only 25 out of 190 cities could meet the National Ambient Air Quality Standards of China and the population-weighted mean of PM2.5 in Chinese cities are 61 μg/m3, ~3 times as high as global population-weighted mean, highlighting a high health risk. PM2.5 concentrations are generally higher in north than in south regions due to relative large PM emissions and unfavorable meteorological conditions for pollution dispersion. A remarkable seasonal variability of PM2.5 is observed with the highest during the winter and the lowest during the summer. Due to the enhanced contributions from dust particles and open biomass burning, high PM2.5 abundances are also found in the spring (in Northwest and West Central China) and autumn (in East China), respectively. In addition, we found the lowest and highest PM2.5 often occurs in the afternoon and evening hours, respectively, associated with daily variation of the boundary layer depth and anthropogenic emissions. The diurnal distribution of the PM2.5-to-CO ratio consistently displays a pronounced peak during the afternoon periods, reflecting a significant contribution of secondary PM formation.
Time-Specific Fear Acts as a Non-Photic Entraining Stimulus of Circadian Rhythms in Rats
Authors: Pellman Blake A. , Kim Earnest , Reilly Melissa , Kashima James , Motch Oleksiy , de la Iglesia Horacio O. , Kim Jeansok J. 
Published: October 2015

AbstractVirtually all animals have endogenous clock mechanisms that “entrain” to the light-dark (LD) cycle and synchronize psychophysiological functions to optimal times for exploring resources and avoiding dangers in the environment. Such circadian rhythms are vital to human mental health, but it is unknown whether circadian rhythms “entrained” to the LD cycle can be overridden by entrainment to daily recurring threats. We show that unsignaled nocturnal footshock caused rats living in an “ethological” apparatus to switch their natural foraging behavior from the dark to the light phase and that this switch was maintained as a free-running circadian rhythm upon removal of light cues and footshocks. Furthermore, this fear-entrained circadian behavior was dependent on an intact amygdala and suprachiasmatic nucleus. Thus, time-specific fear can act as a non-photic entraining stimulus for the circadian system and limbic centers encoding aversive information are likely part of the circadian oscillator network that temporally organizes behavior.
Distinct roles of the RasGAP family proteins in C. elegans associative learning and memory
Authors: Gyurkó M. Dávid , Csermely Péter , Sőti Csaba , Steták Attila 
Published: October 2015

AbstractThe Ras GTPase activating proteins (RasGAPs) are regulators of the conserved Ras/MAPK pathway. Various roles of some of the RasGAPs in learning and memory have been reported in different model systems, yet, there is no comprehensive study to characterize all gap genes in any organism. Here, using reverse genetics and neurobehavioural tests, we studied the role of all known genes of the rasgap family in C. elegans in associative learning and memory. We demonstrated that their proteins are implicated in different parts of the learning and memory processes. We show that gap-1 contribute redundantly with gap-3 to the chemosensation of volatile compounds, gap-1 plays a major role in associative learning, while gap-2 and gap-3 are predominantly required for short- and long-term associative memory. Our results also suggest that the C. elegans Ras orthologue let-60 is involved in multiple processes during learning and memory. Thus, we show that the different classes of RasGAP proteins are all involved in cognitive function and their complex interplay ensures the proper formation and storage of novel information in C. elegans.
HMGB1 induction of clusterin creates a chemoresistant niche in human prostate tumor cells
Authors: Zhou Junmin , Chen Xianghong , Gilvary Danielle L. , Tejera Melba M. , Eksioglu Erika A. , Wei Sheng , Djeu Julie Y. 
Published: October 2015

AbstractDevelopment of chemoresistance, especially to docetaxel (DTX), is the primary barrier to the cure of castration-resistant prostate cancer but its mechanism is obscure. Here, we report a seminal crosstalk between dying and residual live tumor cells during treatment with DTX that can result in outgrowth of a chemoresistant population. Survival was due to the induction of secretory/cytoplasmic clusterin (sCLU), which is a potent anti-apoptotic protein known to bind and sequester Bax from mitochondria, to prevent caspase 3 activation. sCLU induction in live cells depended on HMGB1 release from dying cells. Supernatants from DTX-treated DU145 tumor cells, which were shown to contain HMGB1, effectively induced sCLU from newly-plated DU145 tumor cells and protected them from DTX toxicity. Addition of anti-HMBG1 to the supernatant or pretreatment of newly-plated DU145 tumor cells with anti-TLR4 or anti-RAGE markedly abrogated sCLU induction and protective effect of the supernatant. Mechanistically, HMGB1 activated NFκB to promote sCLU gene expression and prevented the translocation of activated Bax to mitochondria to block cell death. Importantly, multiple currently-used chemotherapeutic drugs could release HMGB1 from tumor cells. These results suggest that acquisition of chemoresistance may involve the HMGB1/TLR4-RAGE/sCLU pathway triggered by dying cells to provide survival advantage to remnant live tumor cells.
Zeta-Fe2O3 – A new stable polymorph in iron(III) oxide family
Authors: Tuček Jiří , Machala Libor , Ono Shigeaki , Namai Asuka , Yoshikiyo Marie , Imoto Kenta , Tokoro Hiroko , Ohkoshi Shin-ichi , Zbořil Radek 
Published: October 2015

AbstractIron(III) oxide shows a polymorphism, characteristic of existence of phases with the same chemical composition but distinct crystal structures and, hence, physical properties. Four crystalline phases of iron(III) oxide have previously been identified: α-Fe2O3 (hematite), β-Fe2O3, γ-Fe2O3 (maghemite) and ε-Fe2O3. All four iron(III) oxide phases easily undergo various phase transformations in response to heating or pressure treatment, usually forming hexagonal α-Fe2O3, which is the most thermodynamically stable Fe2O3 polymorph under ambient conditions. Here, from synchrotron X-ray diffraction experiments, we report the formation of a new iron(III) oxide polymorph that we have termed ζ-Fe2O3 and which evolved during pressure treatment of cubic β-Fe2O3 ("Equation missing" space group) at pressures above 30 GPa. Importantly, ζ-Fe2O3 is maintained after pressure release and represents the first monoclinic Fe2O3 polymorph (I2/a space group) that is stable at atmospheric pressure and room temperature. ζ-Fe2O3 behaves as an antiferromagnet with a Néel transition temperature of ~69 K. The complex mechanism of pressure-induced transformation of β-Fe2O3, involving also the formation of Rh2O3-II-type Fe2O3 and post-perovskite-Fe2O3 structure, is suggested and discussed with respect to a bimodal size distribution of precursor nanoparticles.
Xenon Blocks Neuronal Injury Associated with Decompression
Authors: Blatteau Jean-Eric , David Hélène N. , Vallée Nicolas , Meckler Cedric , Demaistre Sebastien , Lambrechts Kate , Risso Jean-Jacques , Abraini Jacques H. 
Published: October 2015

AbstractDespite state-of-the-art hyperbaric oxygen (HBO) treatment, about 30% of patients suffering neurologic decompression sickness (DCS) exhibit incomplete recovery. Since the mechanisms of neurologic DCS involve ischemic processes which result in excitotoxicity, it is likely that HBO in combination with an anti-excitotoxic treatment would improve the outcome in patients being treated for DCS. Therefore, in the present study, we investigated the effect of the noble gas xenon in an ex vivo model of neurologic DCS. Xenon has been shown to provide neuroprotection in multiple models of acute ischemic insults. Fast decompression compared to slow decompression induced an increase in lactate dehydrogenase (LDH), a well-known marker of sub-lethal cell injury. Post-decompression administration of xenon blocked the increase in LDH release induced by fast decompression. These data suggest that xenon could be an efficient additional treatment to HBO for the treatment of neurologic DCS.
Toward Improved Lifetimes of Organic Solar Cells under Thermal Stress: Substrate-Dependent Morphological Stability of PCDTBT:PCBM Films and Devices
Authors: Li Zhe , Ho Chiu Kar , Shahid Ashraf Raja , Fearn Sarah , Dattani Rajeev , Cheng Wong Him , Tan Ching-Hong , Wu Jiaying , Cabral João T. , Durrant James R. 
Published: October 2015

AbstractMorphological stability is a key requirement for outdoor operation of organic solar cells. We demonstrate that morphological stability and lifetime of polymer/fullerene based solar cells under thermal stress depend strongly on the substrate interface on which the active layer is deposited. In particular, we find that the stability of benchmark PCDTBT/PCBM solar cells under modest thermal stress is substantially increased in inverted solar cells employing a ZnO substrate compared to conventional devices employing a PEDOT:PSS substrate. This improved stability is observed to correlate with PCBM nucleation at the 50 nm scale, which is shown to be strongly influenced by different substrate interfaces. Employing this approach, we demonstrate remarkable thermal stability for inverted PCDTBT:PC70BM devices on ZnO substrates, with negligible (<2%) loss of power conversion efficiency over 160 h under 85 °C thermal stress and minimal thermally induced “burn-in” effect. We thus conclude that inverted organic solar cells, in addition to showing improved environmental stability against ambient humidity exposure as widely reported previously, can also demonstrate enhanced morphological stability. As such we show that the choice of suitable substrate interfaces may be a key factor in achieving prolonged lifetimes for organic solar cells under thermal stress conditions.
Dysfunctional Default Mode Network in Methadone Treated Patients Who Have a Higher Heroin Relapse Risk
Authors: Li Wei , Li Qiang , Wang Defeng , Xiao Wei , Liu Kai , Shi Lin , Zhu Jia , Li Yongbin , Yan Xuejiao , Chen Jiajie , Ye Jianjun , Li Zhe , Wang Yarong , Wang Wei 
Published: October 2015

AbstractThe purpose of this study was to identify whether heroin relapse is associated with changes in the functional connectivity of the default mode network (DMN) during methadone maintenance treatment (MMT). Resting-state functional magnetic resonance imaging (fMRI) data of chronic heroin relapsers (HR) (12 males, 1 female, age: 36.1 ± 6.9 years) and abstainers (HA) (11males, 2 female; age: 42.1 ± 8.1 years) were investigated with an independent component analysis to address the functional connectivity of their DMN. Group comparison was then performed between the relapsers and abstainers. Our study found that the left inferior temporal gyrus and the right superior occipital gyrus associated with DMN showed decreased functional connectivity in HR when compared with HA, while the left precuneus and the right middle cingulum had increased functional connectivity. Mean intensity signal, extracted from left inferior temporal gyrus of HR patients, showed a significant negative correlation corresponding to the degree of heroin relapse. These findings suggest that altered functional connectivity of DMN may contribute to the potential neurobiological mechanism(s) of heroin relapse and have a predictive value concerning heroin relapse under MMT.
Co/Mo bimetallic addition to electrolytic manganese dioxide for oxygen generation in acid medium
Authors: Delgado Dario , Minakshi Manickam , McGinnity Justin , Kim Dong-Jin 
Published: October 2015

AbstractAn efficient electrocatalyst comprising inexpensive and earth-abundant materials for the oxygen evolution reaction (OER) is crucial for the development of water electrolysis. In this work, in-situ addition of cobalt/molybdenum ions to the electrolytic manganese dioxide has been shown to be beneficial for the OER in acid solution as its overpotential performed better (305 mV) than that of the commercial DSA® (341 mV) at 100 mA cm−2. The OER was investigated at ambient temperature in 2 M H2SO4 solution on the modified EMD (MnMoCoO) electrodes. The energy efficiency of the MnMoCoO electrodes improved significantly with the amount of Co in the plating solution. For the electrodeposited catalysts, physico-chemical and electrochemical measurements were conducted including static overpotentials. The better performance of the modified EMD was attributed to an improved charge transfer resistance (Rct; 0.290 Ω cm2), average roughness factor (rf; 429) and decrease in water content in the electrodeposited catalysts. The kinetic parameters obtained on MnMoCoO catalysts were compared and discussed according to the cobalt concentration.
Efficient Photocatalytic Activities of TiO2 Hollow Fibers with Mixed Phases and Mesoporous Walls
Authors: Hou Huilin , Shang Minghui , Wang Lin , Li Wenge , Tang Bin , Yang Weiyou 
Published: October 2015

AbstractCurrently, Degussa P25, with the typical mixed phases of anatase and rutile TiO2, is widely applied as the commercial photocatalysts. However, there are still some of obstacles for the P25 nanoparticles with totally high photocatalytic activities, especially for the catalytic stability due to their inevitable aggregation of the nanoparticles when used as the photocatalysts. In the present work, we reported the exploration of a novel TiO2 photocatalyst, which could offer an ideal platform for synergetic combination of the mixed-phase composition, hollow architecture and mesoporous walls for the desired excellent photocatalytic efficiency and robust stability. The mesoporous TiO2 hollow nanofibers were fabricated via a facile single capillary electrospinning technique, in which the foaming agents were used for creating mesopores throughout the walls of the hollow fibers. The obtained hollow fibers exhibit a high purity and possess the mixed phases of 94.6% anatase and 5.4% rutile TiO2. As compared to P25, the as-fabricated mesoporous TiO2 hollow fibers exhibited much higher efficient photocatalytic activities and stabilities toward the hydrogen evolution with a rate of ~499.1 μmol g−1·h−1 and ~99.5% degradation Rhodamine B (RhB) in 60 min, suggesting their promising application in efficient photocatalysts.
The strength of electron electron correlation in Cs3C60
Authors: Baldassarre L. , Perucchi A. , Mitrano M. , Nicoletti D. , Marini C. , Pontiroli D. , Mazzani M. , Aramini M. , Riccó M. , Giovannetti G. , Capone M. , Lupi S. 
Published: October 2015

AbstractCs3C60 is an antiferromagnetic insulator that under pressure (P) becomes metallic and superconducting below Tc = 38 K. The superconducting dome present in the T − P phase diagram close to a magnetic state reminds what found in superconducting cuprates and pnictides, strongly suggesting that superconductivity is not of the conventional Bardeen-Cooper-Schrieffer (BCS) type We investigate the insulator to metal transition induced by pressure in Cs3C60 by means of infrared spectroscopy supplemented by Dynamical Mean-Field Theory calculations. The insulating compound is driven towards a metallic-like behaviour, while strong correlations survive in the investigated pressure range. The metallization process is accompanied by an enhancement of the Jahn-Teller effect. This shows that electronic correlations are crucial in determining the insulating behaviour at ambient pressure and the bad metallic nature for increasing pressure. On the other hand, the relevance of the Jahn-Teller coupling in the metallic state confirms that phonon coupling survives in the presence of strong correlations.
A regulatory loop containing miR-26a, GSK3β and C/EBPα regulates the osteogenesis of human adipose-derived mesenchymal stem cells
Authors: Wang Zi , Xie Qing , Yu Zhang , Zhou Huifang , Huang Yazhuo , Bi Xiaoping , Wang Yefei , Shi Wodong , Sun Hao , Gu Ping , Fan Xianqun 
Published: October 2015

AbstractElucidating the molecular mechanisms responsible for osteogenesis of human adipose-derived mesenchymal stem cells (hADSCs) will provide deeper insights into the regulatory mechanisms of this process and help develop more efficient methods for cell-based therapies. In this study, we analysed the role of miR-26a in the regulation of hADSC osteogenesis. The endogenous expression of miR-26a increased during the osteogenic differentiation. The overexpression of miR-26a promoted hADSC osteogenesis, whereas osteogenesis was repressed by miR-26a knockdown. Additionally, miR-26a directly targeted the 3′UTR of the GSK3β, suppressing the expression of GSK3β protein. Similar to the effect of overexpressing miR-26a, the knockdown of GSK3β promoted osteogenic differentiation, whereas GSK3β overexpression inhibited this process, suggesting that GSK3β acted as a negative regulator of hADSC osteogenesis. Furthermore, GSK3β influences Wnt signalling pathway by regulating β-catenin and subsequently altered the expression of its downstream target C/EBPα. In turn, C/EBPα transcriptionally regulated the expression of miR-26a by physically binding to the CTDSPL promoter region. Taken together, our data identified a novel feedback regulatory circuitry composed of miR-26a, GSK3β and C/EBPα, the function of which might contribute to the regulation of hADSC osteogenesis. Our findings provided new insights into the function of miR-26a and the mechanisms underlying osteogenesis of hADSCs.
Systems pharmacology-based dissection of mechanisms of Chinese medicinal formula Bufei Yishen as an effective treatment for chronic obstructive pulmonary disease
Authors: Li Jiansheng , Zhao Peng , Li Ya , Tian Yange , Wang Yonghua 
Published: October 2015

AbstractThe present work adopted a systems pharmacology-based approach to provide new insights into the active compounds and therapeutic targets of Bufei Yishen formula (BYF) for the treatment of chronic obstructive pulmonary disease (COPD). In addition, we established a rat model of cigarette smoke- and bacterial infection-induced COPD to validate the mechanisms of BYF action that were predicted in systems pharmacology study. The systems pharmacology model derived 216 active compounds from BYF and 195 potential targets related to various diseases. The compound-target network showed that each herbal drug in the BYF formula acted on similar targets, suggesting potential synergistic effects among these herbal drugs. The ClueGo assay, a Cytoscape plugin, revealed that most targets were related to activation of MAP kinase and matrix metalloproteinases. By using target-diseases network analysis, we found that BYF had great potential to treatment of multiple diseases, such as respiratory tract diseases, immune system and cardiovascular diseases. Furthermore, we found that BYF had the ability to prevent COPD and its comorbidities, such as ventricular hypertrophy, in vivo. Moreover, BYF inhibited the inflammatory cytokine and hypertrophic factors expression, protease-antiprotease imbalance and the collagen deposition, which may be the underlying mechanisms of action of BYF.
Harmonizing HeLa cell cytoskeleton behavior by multi-Ti oxide phased nanostructure synthesized through ultrashort pulsed laser
Authors: Chinnakkannu Vijayakumar Chandramouli , Venkatakrishnan Krishnan , Tan Bo 
Published: October 2015

AbstractKnowledge about cancer cell behavior on heterogeneous nanostructures is relevant for developing a distinct biomaterial that can actuate cancer cells. In this manuscript, we have demonstrated a harmonized approach of forming multi Ti-oxide phases in a nanostructure (MTOP nanostructure) for its unique cancer cell controlling behavior.Conventionally, single phases of TiO2 are used for targeted therapy and as drug carrier systems.In this research, we have shown a biomaterial that can control HeLa cells diligently using a combination of TiO, Ti3O and TiO2 phases when compared to fibroblast (NIH3T3) cells.MTOP-nanostructures are generated by varying the ionization energy in the vapor plume of the ultrashort pulse laser; this interaction with the material allows accurate tuning and composition of phases within the nanostructure. In addition, the lattice spacing of MTOP-nanostructures was analyzed as shown by HR-TEM investigations. An FESEM investigation of MTOP-nanostructures revealed a greater reduction of HeLa cells relative to fibroblast cells. Altered cell adhesion was followed by modulation of HeLa cell architecture with a significant reduction of actin stress fibers.The intricate combination of MTOP-nanostructures renders a biomaterial that can precisely alter HeLa cell but not fibroblast cell behavior, filling a void in the research for a biomaterial to modulate cancer cell behavior.
Electronic Structures of Clusters of Hydrogen Vacancies on Graphene
Authors: Wu Bi-Ru , Yang Chih-Kai 
Published: October 2015

AbstractHydrogen vacancies in graphane are products of incomplete hydrogenation of graphene. The missing H atoms can alter the electronic structure of graphane and therefore tune the electronic, magnetic and optical properties of the composite. We systematically studied a variety of well-separated clusters of hydrogen vacancies in graphane, including the geometrical shapes of triangles, parallelograms, hexagons and rectangles, by first-principles density functional calculation. The results indicate that energy levels caused by the missing H are generated in the broad band gap of pure graphane. All triangular clusters of H vacancies are magnetic, the larger the triangle the higher the magnetic moment. The defect levels introduced by the missing H in triangular and parallelogram clusters are spin-polarized and can find application in optical transition. Parallelograms and open-ended rectangles are antiferromagnetic and can be used for nanoscale registration of digital information.