bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasmon-assisted high-harmonic generation in graphene
Authors: Cox Joel D. , Marini Andrea , de Abajo F. Javier García 
Published: February 2017

AbstractHigh-harmonic generation in condensed-matter systems is both a source of fundamental insight into quantum electron motion and a promising candidate to realize compact ultraviolet and ultrafast light sources. While graphene is anticipated to efficiently generate high-order harmonics due to its anharmonic charge-carrier dispersion, experiments performed on extended samples using THz illumination have revealed only a weak effect. The situation is further complicated by the enormous electromagnetic field intensities required by this highly nonperturbative nonlinear optical phenomenon. Here we argue that the large light intensity required for high-harmonic generation to occur can be reached by exploiting localized plasmons in doped graphene nanostructures. We demonstrate through rigorous time-domain simulations that the synergistic combination of strong plasmonic near-field enhancement and a pronounced intrinsic nonlinearity result in efficient broadband high-harmonic generation within a single material. Our results support the strong potential of nanostructured graphene as a robust, electrically tunable platform for high-harmonic generation.
Enhanced oxidation resistance of active nanostructures via dynamic size effect
Authors: Liu Yun , Yang Fan , Zhang Yi , Xiao Jianping , Yu Liang , Liu Qingfei , Ning Yanxiao , Zhou Zhiwen , Chen Hao , Huang Wugen , Liu Ping , Bao Xinhe 
Published: February 2017

AbstractA major challenge limiting the practical applications of nanomaterials is that the activities of nanostructures (NSs) increase with reduced size, often sacrificing their stability in the chemical environment. Under oxidative conditions, NSs with smaller sizes and higher defect densities are commonly expected to oxidize more easily, since high-concentration defects can facilitate oxidation by enhancing the reactivity with O2 and providing a fast channel for oxygen incorporation. Here, using FeO NSs as an example, we show to the contrary, that reducing the size of active NSs can drastically increase their oxidation resistance. A maximum oxidation resistance is found for FeO NSs with dimensions below 3.2 nm. Rather than being determined by the structure or electronic properties of active sites, the enhanced oxidation resistance originates from the size-dependent structural dynamics of FeO NSs in O2. We find this dynamic size effect to govern the chemical properties of active NSs.
Towards high-resolution laser ionization spectroscopy of the heaviest elements in supersonic gas jet expansion
Authors: Ferrer R. , Barzakh A. , Bastin B. , Beerwerth R. , Block M. , Creemers P. , Grawe H. , de Groote R. , Delahaye P. , Fléchard X. , Franchoo S. , Fritzsche S. , Gaffney L. P. , Ghys L. , Gins W. , Granados C. , Heinke R. , Hijazi L. , Huyse M. , Kron T. , Kudryavtsev Yu. , Laatiaoui M. , Lecesne N. , Loiselet M. , Lutton F. , Moore I. D. , Martínez Y. , Mogilevskiy E. , Naubereit P. , Piot J. , Raeder S. , Rothe S. , Savajols H. , Sels S. , Sonnenschein V. , Thomas J-C , Traykov E. , Van Beveren C. , Van den Bergh P. , Van Duppen P. , Wendt K. , Zadvornaya A. 
Published: February 2017

AbstractResonant laser ionization and spectroscopy are widely used techniques at radioactive ion beam facilities to produce pure beams of exotic nuclei and measure the shape, size, spin and electromagnetic multipole moments of these nuclei. However, in such measurements it is difficult to combine a high efficiency with a high spectral resolution. Here we demonstrate the on-line application of atomic laser ionization spectroscopy in a supersonic gas jet, a technique suited for high-precision studies of the ground- and isomeric-state properties of nuclei located at the extremes of stability. The technique is characterized in a measurement on actinium isotopes around theN=126 neutron shell closure. A significant improvement in the spectral resolution by more than one order of magnitude is achieved in these experiments without loss in efficiency.
Clonal reversal of ageing-associated stem cell lineage bias via a pluripotent intermediate
Authors: Wahlestedt Martin , Erlandsson Eva , Kristiansen Trine , Lu Rong , Brakebusch Cord , Weissman Irving L. , Yuan Joan , Martin-Gonzalez Javier , Bryder David 
Published: February 2017

AbstractAgeing associates with significant alterations in somatic/adult stem cells and therapies to counteract these might have profound benefits for health. In the blood, haematopoietic stem cell (HSC) ageing is linked to several functional shortcomings. However, besides the recent realization that individual HSCs might be preset differentially already from young age, HSCs might also age asynchronously. Evaluating the prospects for HSC rejuvenation therefore ultimately requires approaching those HSCs that are functionally affected by age. Here we combine genetic barcoding of aged murine HSCs with the generation of induced pluripotent stem (iPS) cells. This allows us to specifically focus on aged HSCs presenting with a pronounced lineage skewing, a hallmark of HSC ageing. Functional and molecular evaluations reveal haematopoiesis from these iPS clones to be indistinguishable from that associating with young mice. Our data thereby provide direct support to the notion that several key functional attributes of HSC ageing can be reversed.
Abnormal strong burn-in degradation of highly efficient polymer solar cells caused by spinodal donor-acceptor demixing
Authors: Li Ning , Perea José Darío , Kassar Thaer , Richter Moses , Heumueller Thomas , Matt Gebhard J. , Hou Yi , Güldal Nusret S. , Chen Haiwei , Chen Shi , Langner Stefan , Berlinghof Marvin , Unruh Tobias , Brabec Christoph J. 
Published: February 2017

AbstractThe performance of organic solar cells is determined by the delicate, meticulously optimized bulk-heterojunction microstructure, which consists of finely mixed and relatively separated donor/acceptor regions. Here we demonstrate an abnormal strong burn-in degradation in highly efficient polymer solar cells caused by spinodal demixing of the donor and acceptor phases, which dramatically reduces charge generation and can be attributed to the inherently low miscibility of both materials. Even though the microstructure can be kinetically tuned for achieving high-performance, the inherently low miscibility of donor and acceptor leads to spontaneous phase separation in the solid state, even at room temperature and in the dark. A theoretical calculation of the molecular parameters and construction of the spinodal phase diagrams highlight molecular incompatibilities between the donor and acceptor as a dominant mechanism for burn-in degradation, which is to date the major short-time loss reducing the performance and stability of organic solar cells.
Sex differences in microglial CX3CR1 signalling determine obesity susceptibility in mice
Authors: Dorfman Mauricio D. , Krull Jordan E. , Douglass John D. , Fasnacht Rachael , Lara-Lince Fernando , Meek Thomas H. , Shi Xiaogang , Damian Vincent , Nguyen Hong T. , Matsen Miles E. , Morton Gregory J. , Thaler Joshua P. 
Published: February 2017

AbstractFemale mice are less susceptible to the negative metabolic consequences of high-fat diet feeding than male mice, for reasons that are incompletely understood. Here we identify sex-specific differences in hypothalamic microglial activation via the CX3CL1-CX3CR1 pathway that mediate the resistance of female mice to diet-induced obesity. Female mice fed a high-fat diet maintain CX3CL1-CX3CR1 levels while male mice show reductions in both ligand and receptor expression. Female Cx3cr1 knockout mice develop ‘male-like’ hypothalamic microglial accumulation and activation, accompanied by a marked increase in their susceptibility to diet-induced obesity. Conversely, increasing brain CX3CL1 levels in male mice through central pharmacological administration or virally mediated hypothalamic overexpression converts them to a ‘female-like’ metabolic phenotype with reduced microglial activation and body-weight gain. These data implicate sex differences in microglial activation in the modulation of energy homeostasis and identify CX3CR1 signalling as a potential therapeutic target for the treatment of obesity.
Improved antitumor activity of TRAIL fusion protein via formation of self-assembling nanoparticle
Authors: Huang Kaizong , Duan Ningjun , Zhang Chunmei , Mo Ran , Hua Zichun 
Published: February 2017

AbstractTumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been known as a promising agent for cancer therapy due to its specific apoptosis-inducing effect on tumor cells rather than most normal cells. However, systemically delivered TRAIL suffers from a rapid clearance from the body with an extremely short half-life. Thermally responsive elastin-like polypeptides (ELPs) are a promising class of temperature sensitive biopolymers based on the structural motif found in mammalian tropoelastin and retain the advantages of polymeric drug delivery systems. We therefore expressed RGD-TRAIL fused with ELP (RGD-TRAIL-ELP) in E. coli. Purification of RGD-TRAIL-ELP was achieved by the conveniently inverse transition cycling (ITC). The purified RGD-TRAIL-ELP without any chemical conjugation was able to self-assemble into nanoparticle under physiological condition. Non-reducing SDS-PAGE results showed that trimer content of RGD-TRAIL-ELP increased 3.4-fold than RGD-TRAIL. Flow cytometry confirmed that RGD-TRAIL-ELP 3-fold enhanced apoptosis-inducing capacity than RGD-TRAIL. Single intraperitoneal injection of the RGD-TRAIL-ELP nanoparticle induced nearly complete tumor regression in the COLO-205 tumor xenograft model. Histological observation confirmed that RGD-TRAIL-ELP induced significant tumor cell apoptosis without apparent liver toxicity. These findings suggested that a great potential application of the RGD-TRAIL-ELP nanoparticle system as a safe and efficient delivery strategy for cancer therapy.
Chemometric-assisted QuEChERS extraction method for post-harvest pesticide determination in fruits and vegetables
Authors: Li Minmin , Dai Chao , Wang Fengzhong , Kong Zhiqiang , He Yan , Huang Ya Tao , Fan Bei 
Published: February 2017

AbstractAn effective analysis method was developed based on a chemometric tool for the simultaneous quantification of five different post-harvest pesticides (2,4-dichlorophenoxyacetic acid (2,4-D), carbendazim, thiabendazole, iprodione, and prochloraz) in fruits and vegetables. In the modified QuEChERS (quick, easy, cheap, effective, rugged and safe) method, the factors and responses for optimization of the extraction and cleanup analyses were compared using the Plackett–Burman (P–B) screening design. Furthermore, the significant factors (toluene percentage, hydrochloric acid (HCl) percentage, and graphitized carbon black (GCB) amount) were optimized using a central composite design (CCD) combined with Derringer’s desirability function (DF). The limits of quantification (LOQs) were estimated to be 1.0 μg/kg for 2,4-D, carbendazim, thiabendazole, and prochloraz, and 1.5 μg/kg for iprodione in food matrices. The mean recoveries were in the range of 70.4–113.9% with relative standard deviations (RSDs) of less than 16.9% at three spiking levels. The measurement uncertainty of the analytical method was determined using the bottom-up approach, which yielded an average value of 7.6%. Carbendazim was most frequently found in real samples analyzed using the developed method. Consequently, the analytical method can serve as an advantageous and rapid tool for determination of five preservative pesticides in fruits and vegetables.
Early Spontaneous Abdominal Bleeding is associated with Poor Outcome in Moderate to Severe Acute Pancreatitis Patients: A Propensity Matched Study
Authors: Chen Yizhe , Zhou Jing , Li Gang , Tong Zhihui , Dong Jie , Pan Yiyuan , Ke Lu , Li Weiqin , Li Jieshou 
Published: February 2017

AbstractAbdominal bleeding is a lethal complication in acute pancreatitis (AP) and it is commonly described as a late event. However, spontaneous intra-abdominal bleeding could occur very early but no study focusing on this phenomenon was published yet. In this study, 1137 AP patients were retrospectively screened and 24 subjects suffering early spontaneous bleeding (ESB) were selected. Meanwhile, a 1:1 well-balanced cohort of non-bleeding patients was generated by propensity score match. The clinical characteristics of these patients were compared and a multiple regression analysis was performed to assess the risk factors for ESB. Besides, patients with massive post-intervention bleeding (PIB) were collected for additional comparison. ESB patients suffered significantly worse outcome than the matched cohort evidenced by dramatically higher mortality than the non-bleeding patients and even the PIB group (54.2% versus 20.8%, P = 0.017; 54.2% versus 31.0%, P = 0.049). The regression analysis demonstrated computer tomography severity index (CTSI; OR, 3.34; 95% CI, 1.995–5.59, P < 0.001) and creatinine (OR, 1.008; 95% CI, 1.004–1.012, P < 0.001) were associated with the occurrence of ESB. In conclusion, ESB is a rare but dangerous complication of moderate-to-severe AP and may result in high mortality. CTSI and creatinine are independent risk factors for the development of ESB.
Autophagy Protects against Palmitic Acid-Induced Apoptosis in Podocytes in vitro
Authors: Jiang Xu-shun , Chen Xue-mei , Wan Jiang-min , Gui Hai-bo , Ruan Xiong-zhong , Du Xiao-gang 
Published: February 2017

AbstractAutophagy is a highly conserved degradation process that is involved in the clearance of proteins and damaged organelles to maintain intracellular homeostasis and cell integrity. Type 2 diabetes is often accompanied by dyslipidemia with elevated levels of free fatty acids (FFAs). Podocytes, as an important component of the filtration barrier, are susceptible to lipid disorders. The loss of podocytes causes proteinuria, which is involved in the pathogenesis of diabetic nephropathy. In the present study, we demonstrated that palmitic acid (PA) promoted autophagy in podocytes. We further found that PA increased the production of reactive oxygen species (ROS) in podocytes and that NAC (N-acetyl-cysteine), a potent antioxidant, significantly eliminated the excessive ROS and suppressed autophagy, indicating that the increased generation of ROS was associated with the palmitic acid-induced autophagy in podocytes. Moreover, we also found that PA stimulation decreased the mitochondrial membrane potential in podocytes and induced podocyte apoptosis, while the inhibition of autophagy by chloroquine (CQ) enhanced palmitic acid-induced apoptosis accompanied by increased ROS generation, and the stimulation of autophagy by rapamycin (Rap) remarkably suppressed palmitic acid-induced ROS generation and apoptosis. Taken together, these in vitro findings suggest that PA-induced autophagy in podocytes is mediated by ROS production and that autophagy plays a protective role against PA-induced podocyte apoptosis.
Multiple sodium channel isoforms mediate the pathological effects of Pacific ciguatoxin-1
Authors: Inserra Marco C. , Israel Mathilde R. , Caldwell Ashlee , Castro Joel , Deuis Jennifer R. , Harrington Andrea M. , Keramidas Angelo , Garcia-Caraballo Sonia , Maddern Jessica , Erickson Andelain , Grundy Luke , Rychkov Grigori Y. , Zimmermann Katharina , Lewis Richard J. , Brierley Stuart M. , Vetter Irina 
Published: February 2017

AbstractHuman intoxication with the seafood poison ciguatoxin, a dinoflagellate polyether that activates voltage-gated sodium channels (NaV), causes ciguatera, a disease characterised by gastrointestinal and neurological disturbances. We assessed the activity of the most potent congener, Pacific ciguatoxin-1 (P-CTX-1), on NaV1.1–1.9 using imaging and electrophysiological approaches. Although P-CTX-1 is essentially a non-selective NaV toxin and shifted the voltage-dependence of activation to more hyperpolarising potentials at all NaV subtypes, an increase in the inactivation time constant was observed only at NaV1.8, while the slope factor of the conductance-voltage curves was significantly increased for NaV1.7 and peak current was significantly increased for NaV1.6. Accordingly, P-CTX-1-induced visceral and cutaneous pain behaviours were significantly decreased after pharmacological inhibition of NaV1.8 and the tetrodotoxin-sensitive isoforms NaV1.7 and NaV1.6, respectively. The contribution of these isoforms to excitability of peripheral C- and A-fibre sensory neurons, confirmed using murine skin and visceral single-fibre recordings, reflects the expression pattern of NaV isoforms in peripheral sensory neurons and their contribution to membrane depolarisation, action potential initiation and propagation.
Anticancer osmium complex inhibitors of the HIF-1α and p300 protein-protein interaction
Authors: Yang Chao , Wang Wanhe , Li Guo-Dong , Zhong Hai-Jing , Dong Zhen-Zhen , Wong Chun-Yuen , Kwong Daniel W. J. , Ma Dik-Lung , Leung Chung-Hang 
Published: February 2017

AbstractThe hypoxia inducible factor (HIF) pathway has been considered to be an attractive anti-cancer target. One strategy to inhibit HIF activity is through the disruption of the HIF-1α–p300 protein-protein interaction. We report herein the identification of an osmium(II) complex as the first metal-based inhibitor of the HIF-1α–p300 interaction. We evaluated the effect of complex 1 on HIF-1α signaling pathway in vitro and in cellulo by using the dual luciferase reporter assay, co-immunoprecipitation assay, and immunoblot assay. Complex 1 exhibited a dose-dependent inhibition of HRE-driven luciferase activity, with an IC50 value of 1.22 μM. Complex 1 interfered with the HIF-1α–p300 interaction as revealed by a dose-dependent reduction of p300 co-precipitated with HIF-1α as the concentration of complex 1 was increased. Complex 1 repressed the phosphorylation of SRC, AKT and STAT3, and had no discernible effect on the activity of NF-κB. We anticipate that complex 1 could be utilized as a promising scaffold for the further development of more potent HIF-1α inhibitors for anti-cancer treatment.
Blood-based omic profiling supports female susceptibility to tobacco smoke-induced cardiovascular diseases
Authors: Chatziioannou Aristotelis , Georgiadis Panagiotis , Hebels Dennie G. , Liampa Irene , Valavanis Ioannis , Bergdahl Ingvar A. , Johansson Anders , Palli Domenico , Chadeau-Hyam Marc , Siskos Alexandros P. , Keun Hector , Botsivali Maria , de Kok Theo M. C. M. , Pérez Almudena Espín , Kleinjans Jos C. S. , Vineis Paolo , Kyrtopoulos Soterios A. ,   The EnviroGenomarkers project consortium, Gottschalk Ralph , van Leeuwen Danitsja , Timmermans Leen , Bendinelli Benedetta , Kelly Rachel , Vermeulen Roel , Portengen Lutzen , Saberi-Hosnijeh Fatemeh , Melin Beatrice , Hallmans Göran , Lenner Per , Athersuch Toby J. , Kogevinas Manolis , Stephanou Euripides G. , Myridakis Antonis , Fazzo Lucia , De Santis Marco , Comba Pietro , Kiviranta Hannu , Rantakokko Panu , Airaksinen Riikka , Ruokojärvi Päivi , Gilthorpe Mark , Fleming Sarah , Fleming Thomas , Tu Yu-Kang , Jonsson Bo , Lundh Thomas , Chen Wei J. , Lee Wen-Chung , Hsiao Chuhsing Kate , Chien Kuo-Liong , Kuo Po-Hsiu , Hung Hung , Liao Shu-Fen 
Published: February 2017

AbstractWe recently reported that differential gene expression and DNA methylation profiles in blood leukocytes of apparently healthy smokers predicts with remarkable efficiency diseases and conditions known to be causally associated with smoking, suggesting that blood-based omic profiling of human populations may be useful for linking environmental exposures to potential health effects. Here we report on the sex-specific effects of tobacco smoking on transcriptomic and epigenetic features derived from genome-wide profiling in white blood cells, identifying 26 expression probes and 92 CpG sites, almost all of which are affected only in female smokers. Strikingly, these features relate to numerous genes with a key role in the pathogenesis of cardiovascular disease, especially thrombin signaling, including the thrombin receptors on platelets F2R (coagulation factor II (thrombin) receptor; PAR1) and GP5 (glycoprotein 5), as well as HMOX1 (haem oxygenase 1) and BCL2L1 (BCL2-like 1) which are involved in protection against oxidative stress and apoptosis, respectively. These results are in concordance with epidemiological evidence of higher female susceptibility to tobacco-induced cardiovascular disease and underline the potential of blood-based omic profiling in hazard and risk assessment.
Altered enhancer transcription underlies Huntington’s disease striatal transcriptional signature
Authors: Le Gras Stéphanie , Keime Céline , Anthony Anne , Lotz Caroline , De Longprez Lucie , Brouillet Emmanuel , Cassel Jean-Christophe , Boutillier Anne-Laurence , Merienne Karine 
Published: February 2017

AbstractEpigenetic and transcriptional alterations are both implicated in Huntington’s disease (HD), a progressive neurodegenerative disease resulting in degeneration of striatal neurons in the brain. However, how impaired epigenetic regulation leads to transcriptional dysregulation in HD is unclear. Here, we investigated enhancer RNAs (eRNAs), a class of long non-coding RNAs transcribed from active enhancers. We found that eRNAs are expressed from many enhancers of mouse striatum and showed that a subset of those eRNAs are deregulated in HDvscontrol mouse striatum. Enhancer regions producing eRNAs decreased in HD mouse striatum were associated with genes involved in striatal neuron identity. Consistently, they were enriched in striatal super-enhancers. Moreover, decreased eRNA expression in HD mouse striatum correlated with down-regulation of associated genes. Additionally, a significant number of RNA Polymerase II (RNAPII) binding sites were lost within enhancers associated with decreased eRNAs in HDvscontrol mouse striatum. Together, this indicates that loss of RNAPII at HD mouse enhancers contributes to reduced transcription of eRNAs, resulting in down-regulation of target genes. Thus, our data support the view that eRNA dysregulation in HD striatum is a key mechanism leading to altered transcription of striatal neuron identity genes, through reduced recruitment of RNAPII at super-enhancers.
Full 3D modelling of pulse propagation enables efficient nonlinear frequency conversion with low energy laser pulses in a single-element tripler
Authors: Kardaś Tomasz M. , Nejbauer Michał , Wnuk Paweł , Resan Bojan , Radzewicz Czesław , Wasylczyk Piotr 
Published: February 2017

AbstractAlthough new optical materials continue to open up access to more and more wavelength bands where femtosecond laser pulses can be generated, light frequency conversion techniques are still indispensable in filling the gaps on the ultrafast spectral scale. With high repetition rate, low pulse energy laser sources (oscillators) tight focusing is necessary for a robust wave mixing and the efficiency of broadband nonlinear conversion is limited by diffraction as well as spatial and temporal walk-off. Here we demonstrate a miniature third harmonic generator (tripler) with conversion efficiency exceeding 30%, producing 246 fs UV pulses via cascaded second order processes within a single laser beam focus. Designing this highly efficient and ultra compact frequency converter was made possible by full 3-dimentional modelling of propagation of tightly focused, broadband light fields in nonlinear and birefringent media.