bluuebunny/crossref_metadata_2025_split huggingface dataset:
Imbalance of the spindle-assembly checkpoint promotes spindle poison-mediated cytotoxicity with distinct kinetics
Authors: Zeng Xiaofang , Xu Wendy Kaichun , Lok Tsun Ming , Ma Hoi Tang , Poon Randy Y. C. 
Published: April 2019

AbstractDisrupting microtubule dynamics with spindle poisons activates the spindle-assembly checkpoint (SAC) and induces mitotic cell death. However, mitotic exit can occur prematurely without proper chromosomal segregation or cytokinesis by a process termed mitotic slippage. It remains controversial whether mitotic slippage increases the cytotoxicity of spindle poisons or the converse. Altering the SAC induces either mitotic cell death or mitotic slippage. While knockout of MAD2-binding protein p31comet strengthened the SAC and promoted mitotic cell death, knockout of TRIP13 had the opposite effect of triggering mitotic slippage. We demonstrated that mitotic slippage prevented mitotic cell death caused by spindle poisons, but reduced subsequent long-term survival. Weakening of the SAC also reduced cell survival in response to spindle perturbation insufficient for triggering mitotic slippage, of which mitotic exit was characterized by displaced chromosomes during metaphase. In either mitotic slippage or mitotic exit with missegregated chromosomes, cell death occurred only after one cell cycle following mitotic exit and increased progressively during subsequent cell cycles. Consistent with these results, transient inhibition of the SAC using an MPS1 inhibitor acted synergistically with spindle perturbation in inducing chromosome missegregation and cytotoxicity. The specific temporal patterns of cell death after mitotic exit with weakened SAC may reconcile the contradictory results from many previous studies.
Ginseng metabolite Protopanaxadiol induces Sestrin2 expression and AMPK activation through GCN2 and PERK
Authors: Jin Hong Ri , Du Charles H , Wang Chong-Zhi , Yuan Chun-Su , Du Wei 
Published: April 2019

AbstractGinseng is one of the most commonly used herbs that is believed to have a variety of biological activities, including reducing blood sugar and cholesterol levels, anti-cancer, and anti-diabetes activities. However, little is known about the molecular mechanisms involved. In this study, we showed that protopanaxadiol (PPD), a metabolite of the protopanaxadiol group ginsenosides that are the major pharmacological constituents of ginsengs, significantly altered the expression of genes involved in metabolism, elevated Sestrin2 (Sesn2) expression, activated AMPK, and induced autophagy. Using CRISPR/CAS9-mediated gene editing and shRNA-mediated gene silencing, we demonstrated that Sesn2 is required for PPD-induced AMPK activation and autophagy. Interestingly, we showed that PPD-induced Sesn2 expression is mediated redundantly by the GCN2/ATF4 amino acid-sensing pathway and the PERK/ATF4 endoplasmic reticulum (ER) stress pathway. Our results suggest that ginseng metabolite PPD modulates the metabolism of amino acids and lipids, leading to the activation of the stress-sensing kinases GCN2 and PERK to induce Sesn2 expression, which promotes AMPK activation, autophagy, and metabolic health.
Origin of apparent light-enhanced and negative capacitance in perovskite solar cells
Authors: Ebadi Firouzeh , Taghavinia Nima , Mohammadpour Raheleh , Hagfeldt Anders , Tress Wolfgang 
Published: April 2019

AbstractSo-called negative capacitance seems to remain an obscure feature in the analysis of the frequency-dependent impedance of perovskite solar cells. It belongs to one of the puzzling peculiarities arising from the mixed ionic-electronic conductivity of this class of semiconductor. Here we show that apparently high capacitances in general (positive and negative) are not related to any capacitive feature in the sense of a corresponding charge accumulation. Instead, they are a natural consequence of slow transients mainly in forward current of the diode upon ion displacement when changing voltage. The transient current leads to a positive or negative ‘capacitance’ dependent on the sign of its gradient. The ‘capacitance’ appears so large because the associated resistance, when thinking of a resistor-capacitor element, results from another physical process, namely modified electronic charge injection and transport. Observable for a variety of devices, it is a rather universal phenomenon related to the hysteresis in the current–voltage curve.
The neural computation of inconsistent choice behavior
Authors: Kurtz-David Vered , Persitz Dotan , Webb Ryan , Levy Dino J. 
Published: April 2019

AbstractHumans are often inconsistent (irrational) when choosing among simple bundles of goods, even without any particular changes to framing or context. However, the neural computations that give rise to such inconsistencies are still unknown. Similar to sensory perception and motor output, we propose that a substantial component of inconsistent behavior is due to variability in the neural computation of value. Here, we develop a novel index that measures the severity of inconsistency of each choice, enabling us to directly trace its neural correlates. We find that the BOLD signal in the vmPFC, ACC, and PCC is correlated with the severity of inconsistency on each trial and with the subjective value of the chosen alternative. This suggests that deviations from rational choice arise in the regions responsible for value computation. We offer a computational model of how variability in value computation is a source of inconsistent choices.
Mosaic pattern formation in exfoliated graphene by mechanical deformation
Authors: Pastore Carbone Maria Giovanna , Manikas Anastasios C. , Souli Ioanna , Pavlou Christos , Galiotis Costas 
Published: April 2019

AbstractGraphene is susceptible to morphological instabilities such as wrinkles and folds, which result from the imposition of thermo-mechanical stresses upon cooling from high temperatures and/ or under biaxial loading. A particular pattern encountered in CVD graphene is that of mosaic formation. Although it is understood that this pattern results from the severe biaxial compression upon cooling from high temperatures, it has not been possible to create such a complex pattern at room temperature by mechanical loading. Herein, we have managed by means of lateral wrinkling induced by tension and Euler buckling resulting from uniaxial compression upon unloading, to create such patterns in exfoliated graphene. We also show that these patterns can be used as channels for trapping or administering fluids at interstitial space between graphene and its support. This opens a whole dearth of new applications in the area of nano-fluidics but also in photo-electronics and sensor technologies.
A chloroplast structured photocatalyst enabled by microwave synthesis
Authors: Xiao Shuning , Zhang Dieqing , Pan Donglai , Zhu Wei , Liu Peijue , Cai Yong , Li Guisheng , Li Hexing 
Published: April 2019

AbstractPhotosynthesis occurs through the synergistic effects of the non-ncontinuously distributed components in the chloroplast. Inspired by nature, we mimic chloroplast and develop a generic approach to synthesize non-continuously distributed semiconductors threaded by carbon nanotubes. In the synthesis, carbon nanotubes serve as microwave antennas to produce local super-hot dots on the surface, which might induce and accelerate various organic/inorganic semiconductors assembly. With the unique nanoscale designed bionic architecture, a chloroplast structured photocatalyst with 3−dimentional dual electron transfer pathways facilitate enhanced photocatalytic performance. The as-synthesized carbon nanotubes-titanium oxide achieves a record-breaking efficiency of 86% for nitric oxide treatment under ultraviolet light irradiation. As a general strategy, a wide variety of carbon nanotubes threaded chloroplast structured nanomaterials can be synthesized and these nanomaterials could find applications in energy chemistry, environmental science and human health.
Network Walking charts transcriptional dynamics of nitrogen signaling by integrating validated and predicted genome-wide interactions
Authors: Brooks Matthew D. , Cirrone Jacopo , Pasquino Angelo V. , Alvarez Jose M. , Swift Joseph , Mittal Shipra , Juang Che-Lun , Varala Kranthi , Gutiérrez Rodrigo A. , Krouk Gabriel , Shasha Dennis , Coruzzi Gloria M. 
Published: April 2019

AbstractCharting a temporal path in gene networks requires linking early transcription factor (TF)-triggered events to downstream effects. We scale-up a cell-based TF-perturbation assay to identify direct regulated targets of 33 nitrogen (N)-early response TFs encompassing 88% of N-responsive Arabidopsis genes. We uncover a duality where each TF is an inducer and repressor, and in vitro cis-motifs are typically specific to regulation directionality. Validated TF-targets (71,836) are used to refine precision of a time-inferred root network, connecting 145 N-responsive TFs and 311 targets. These data are used to chart network paths from direct TF1-regulated targets identified in cells to indirect targets responding onlyin plantavia Network Walking. We uncover network paths from TGA1 and CRF4 to direct TF2targets, which in turn regulate 76% and 87% of TF1indirect targetsin planta, respectively. These results have implications for N-use and the approach can reveal temporal networks for any biological system.
Beating the exclusion rule against the coexistence of robust luminescence and ferromagnetism in chalcogenide monolayers
Authors: Duan Hengli , Guo Peng , Wang Chao , Tan Hao , Hu Wei , Yan Wensheng , Ma Chao , Cai Liang , Song Li , Zhang Wenhua , Sun Zhihu , Wang Linjun , Zhao Wenbo , Yin Yuewei , Li Xiaoguang , Wei Shiqiang 
Published: April 2019

AbstractMonolayer chalcogenide semiconductors with both luminescent and ferromagnetic properties are dreamed for simultaneous polarization and detection of the valley degree of freedom in valleytronics. However, a conventional chalcogenide monolayer lacks these coexisting properties due to their mutually exclusive origins. Herein we demonstrate that robust ferromagnetism and photoluminescence (PL) could be achieved in a (Co, Cr)-incorporated single monolayer MoS2, where the ferromagnetic interaction is activated by Co ions, and the nonradiative recombination channels of excitons is cut off by Cr ions. This strategy brings a 90-fold enhancement of saturation magnetization and 35-fold enhancement of PL intensity than the pristine MoS2 monolayer. The main reasons for the coexisting ferromagnetism and PL are the electronic interactions between the impurity bands of atop Cr adatoms and substitutional Co atoms, as well as the increased content of neutral exciton. Our findings could extend the applications of two-dimensional chalcogenides into spintronics, valleytronic and photoelectric devices.
Experimental observation of classical analogy of topological entanglement entropy
Authors: Chen Tian , Zhang Shihao , Zhang Yi , Liu Yulong , Kou Su-Peng , Sun Houjun , Zhang Xiangdong 
Published: April 2019

AbstractLong-range entanglement is an important aspect of the topological orders, so efficient methods to characterize the long-range entanglement are often needed. In this regard, topological entanglement entropy (TEE) is often used for such a purpose but the experimental observation of TEE in a topological order remains a challenge. Here, we propose a scheme to observe TEE in the topological order by constructing specific minimum entropy states (MESs). We then experimentally construct the classical microwave analogs of the MESs and simulate the nontrivial topological order with the TEE in Kitaev toric code, which is in agreement with theoretical predictions. We also experimentally simulate the transition from Z2 topologically ordered state to topologically trivial state.
N-terminal syndecan-2 domain selectively enhances 6-O heparan sulfate chains sulfation and promotes VEGFA165-dependent neovascularization
Authors: Corti Federico , Wang Yingdi , Rhodes John M. , Atri Deepak , Archer-Hartmann Stephanie , Zhang Jiasheng , Zhuang Zhen W. , Chen Dongying , Wang Tianyun , Wang Zhirui , Azadi Parastoo , Simons Michael 
Published: April 2019

AbstractThe proteoglycan Syndecan-2 (Sdc2) has been implicated in regulation of cytoskeleton organization, integrin signaling and developmental angiogenesis in zebrafish. Here we report that mice with global and inducible endothelial-specific deletion of Sdc2 display marked angiogenic and arteriogenic defects and impaired VEGFA165signaling. No such abnormalities are observed in mice with deletion of the closely related Syndecan-4 (Sdc4) gene. These differences are due to a significantly higher 6-O sulfation level in Sdc2 versus Sdc4 heparan sulfate (HS) chains, leading to an increase in VEGFA165binding sites and formation of a ternary Sdc2-VEGFA165-VEGFR2 complex which enhances VEGFR2 activation. The increased Sdc2 HS chains 6-O sulfation is driven by a specific N-terminal domain sequence; the insertion of this sequence in Sdc4 N-terminal domain increases 6-O sulfation of its HS chains and promotes Sdc2-VEGFA165-VEGFR2 complex formation. This demonstrates the existence of core protein-determined HS sulfation patterns that regulate specific biological activities.
Experimental identification of quantum spin liquids
Authors: Wen Jinsheng , Yu Shun-Li , Li Shiyan , Yu Weiqiang , Li Jian-Xin 
Published: April 2019

AbstractIn condensed matter physics there is a novel phase termed ‘quantum spin liquid’, in which strong quantum fluctuations prevent long-range magnetic order from being estab lished, and so electron spins do not form an ordered pattern but remain liquid-like even at absolute zero temperature. Such a phase is not involved in any spontaneous symmetry breaking and local order parameter, and to understand it is beyond conventional phase transition theory. Due to the rich physics and exotic properties of quantum spin liquids, such as long-range entanglement and fractional quantum excitations, which are believed to hold great potential for quantum communication and computation, they have been intensively studied since the concept was proposed in 1973 by P.W. Anderson. Currently, experimental identification of a quantum spin liquid remains a great challenge. Here, we highlight some interesting experimental progress that has been made recently. We also discuss outstanding issues and raise questions that we consider to be important for future research.
ETV5 links the FGFR3 and Hippo signalling pathways in bladder cancer
Authors: di Martino Erica , Alder Olivia , Hurst Carolyn D. , Knowles Margaret A. 
Published: April 2019

AbstractActivating mutations of fibroblast growth factor receptor 3 (FGFR3) are common in urothelial carcinoma of the bladder (UC). Silencing or inhibition of mutant FGFR3 in bladder cancer cell lines is associated with decreased malignant potential, confirming its important driver role in UC. However, understanding of how FGFR3 activation drives urothelial malignant transformation remains limited. We have previously shown that mutant FGFR3 alters the cell-cell and cell-matrix adhesion properties of urothelial cells, resulting in loss of contact-inhibition of proliferation. In this study, we investigate a transcription factor of the ETS-family, ETV5, as a putative effector of FGFR3 signalling in bladder cancer. We show that FGFR3 signalling induces a MAPK/ERK-mediated increase in ETV5 levels, and that this results in increased level of TAZ, a co-transcriptional regulator downstream of the Hippo signalling pathway involved in cell-contact inhibition. We also demonstrate that ETV5 is a key downstream mediator of the oncogenic effects of mutant FGFR3, as its knockdown in FGFR3-mutant bladder cancer cell lines is associated with reduced proliferation and anchorage-independent growth. Overall this study advances our understanding of the molecular alterations occurring during urothelial malignant transformation and indicates TAZ as a possible therapeutic target in FGFR3-dependent bladder tumours.
Genetic data improve the assessment of the conservation status based only on herbarium records of a Neotropical tree
Authors: Muniz André Carneiro , Lemos-Filho José Pires , Buzatti Renata Santiago de Oliveira , Ribeiro Priciane Cristina Correa , Fernandes Fernando Moreira , Lovato Maria Bernadete 
Published: April 2019

AbstractAlthough there is a consensus among conservation biologists about the importance of genetic information, the assessment of extinction risk and conservation decision-making generally do not explicitly consider this type of data. Genetic data can be even more important in species where little other information is available. In this study, we investigated a poorly known legume tree,Dimorphandra exaltata, from the Brazilian Atlantic Forest, a hotspot for conservation. We coupled species distribution models and geospatial assessment based on herbarium records with population genetic analyses to evaluate its genetic status and extinction risk, and to suggest conservation measures.Dimorphandra exaltatashows low genetic diversity, inbreeding, and genetic evidence of decrease in population size, indicating that the species is genetically depleted. Geospatial assessment classified the species as Endangered. Species distribution models projected a decrease in range size in the near future (2050). The genetic status of the species suggests low adaptive potential, which compromises its chances of survival in the face of ongoing climatic change. Altogether, our coupled analyses show that the species is even more threatened than indicated by geospatial analyses alone. Thus, conservation measures that take into account genetic data and the impacts of climate change in the species should be implemented.
Influence of Chemically Disrupted Photosynthesis on Cyanobacterial Thylakoid Dynamics in Synechocystis sp. PCC 6803
Authors: Stingaciu Laura-Roxana , O’Neill Hugh M. , Liberton Michelle , Pakrasi Himadri B. , Urban Volker S. 
Published: April 2019

AbstractThe photosynthetic machinery of the cyanobacterium Synechocystis sp. PCC 6803 resides in flattened membrane sheets called thylakoids, situated in the peripheral part of the cellular cytoplasm. Under photosynthetic conditions these thylakoid membranes undergo various dynamical processes that could be coupled to their energetic functions. Using Neutron Spin Echo Spectroscopy (NSE), we have investigated the undulation dynamics of Synechocystis sp. PCC 6803 thylakoids under normal photosynthetic conditions and under chemical treatment with DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea), an herbicide that disrupts photosynthetic electron transfer. Our measurements show that DCMU treatment has a similar effect as dark conditions, with differences in the undulation modes of the untreated cells compared to the chemically inhibited cells. We found that the disrupted membranes are 1.5-fold more rigid than the native membranes during the dark cycle, while in light they relax approximately 1.7-fold faster than native and they are 1.87-fold more flexible. The strength of the herbicide disruption effect is characterized further by the damping frequency of the relaxation mode and the decay rate of the local shape fluctuations. In the dark, local thicknesses and shape fluctuations relax twice as fast in native membranes, at 17% smaller mode amplitude, while in light the decay rate of local fluctuations is 1.2-fold faster in inhibited membranes than in native membranes, at 56% higher amplitude. The disrupted electron transfer chain and the decreased proton motive force within the lumenal space partially explain the variations observed in the mechanical properties of the Synechocystis membranes, and further support the hypothesis that the photosynthetic process is tied to thylakoid rigidity in this type of cyanobacterial cell.
Gas flux cyclic regime at an open vent magmatic column inferred from seismic and acoustic records
Authors: Kondo Gen , Aoyama Hiroshi , Nishimura Takeshi , Ripepe Maurizio , Lacanna Giorgio , Genco Riccardo , Kawaguchi Ryohei , Yamada Taishi , Miwa Takahiro , Fujita Eisuke 
Published: April 2019

AbstractOn August 7, 2014, a new effusive vent opened on the northern flank of Stromboli. A characteristic pattern was observed in both seismic and infrasonic signal amplitudes prior to this effusive eruption. The pattern consisted of the repeating cycle: (1) quiet phase, (2) puffing phase, and (3) explosion phase. Correlation between seismic and infrasound signal suggests that pulses in the puffing phase were caused by repetitive bursts of small gas pockets at the central crater, while the explosion phase coincided with an explosion at the central crater. We show that degassing of the magma column occurred in cycles of increasing gas flux, which controlled the transition from a bubbly flow (puffing phase), to a slug flow (explosion phase) gas regime. The quiet phase was characterized by a constant time length of 150 s, indicating that the gas rose in the magma column as well-organized waves of gas layers. These cycles represent cyclic changes of the gas flux regime in the shallow magma column, associated with increases in the magma-gas supply input rate before the effusive eruption.
Randomized, Double-blind, Placebo-controlled Study of a Multispecies Probiotic Mixture in Nonalcoholic Fatty Liver Disease
Authors: Ahn Sang Bong , Jun Dae Won , Kang Bo-Kyeong , Lim Jong Hyun , Lim Sanghyun , Chung Myung-Jun 
Published: April 2019

AbstractThe intestinal microbiota is closely associated with the development of obesity and nonalcoholic fatty liver disease (NAFLD). This study investigated the effects of probiotic treatment on visceral fat area (VFA) and intrahepatic fat (IHF) fraction in NAFLD. Sixty-eight obese NAFLD patients (>5% proton density fat fraction [PDFF] on magnetic resonance imaging [MRI]) were randomized to probiotic and placebo groups for 12 weeks. The probiotic mixture included 6 bacterial species. VFA and IHF were measured using the MRI-PDFF technique. Body weight and total body fat were reduced in the probiotic group but not in the placebo group. The mean IHF fraction was reduced after 12 weeks of treatment in the probiotic group compared to that at baseline (from 16.3 ± 15.0% to 14.1 ± 7.7%, p = 0.032) but was not reduced in the placebo group. The decrease in IHF (mean difference: −2.61%, p = 0.012) was also greater in the probiotic group than in the placebo group. Reduction of triglyceride was greater in the probiotic treatment group than in the placebo group (mean difference: −34.0 mg/dl, p = 0.0033). However, the changes in IHF percentage and triglyceride levels were not different between placebo and control groups after adjusting for changes in body weight. Treatment with probiotics for 12 weeks resulted in significant reduction in IHF and body weight in obese NAFLD patients.