bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanoparticles of Chlorin Dimer with Enhanced Absorbance for Photoacoustic Imaging and Phototherapy
Authors: Zheng Xiaohua , Wang Lei , Liu Shi , Zhang Wei , Liu Feng , Xie Zhigang 
Published: April 2018

AbstractNanoparticle assembled from organic molecules is a versatile platform to integrate various functionalities for theranostics. In this work, nanoparticles are constructed from chlorin dimers that are synthesized by reducing porphyrin molecules. Chlorin dimers can assemble into nanoscale aggregates in the absence of surfactants or other auxiliary agent. The resulting nanoparticles of chlorin dimer exhibit much higher absorbance than the porphyrin counterparts, resulting in enhanced photodynamic and photothermal activity upon irradiation. The forming nanoparticles can be effectively endocytosed by the tumor cells, inducing apoptosis under irradiation. Tumor growth on mice model is inhibited by the photodynamic and photothermal treatment in vivo. Furthermore, this nanoparticle can be used for photoacoustic imaging. It is believed that the integrated imaging and phototherapeutic capability in one nanoparticle is beneficial for future cancer diagnosis, therapy, and molecular imaging.
Liquid Exfoliation of Icosahedral Quasicrystals
Authors: Yadav Thakur Prasad , Woellner Cristiano F. , Sinha Shyam K. , Sharifi Tiva , Apte Amey , Mukhopadhyay Nilay Krishna , Srivastava Onkar Nath , Vajtai Robert , Galvao Douglas S. , Tiwary Chandra Sekhar , Ajayan Pulickel M. 
Published: April 2018

AbstractThe realization of quasicrystals has attracted a considerable attention due to their unusual structures and properties. The concept of quasicrystals in the atomically thin materials is even more appealing due to the in‐plane covalent bonds and weak interlayer interactions. Here, it is demonstrated that 2D quasicrystals can be created/isolated from bulk phases because of long‐range interlayer ordered aperiodic arrangements. An ultrasonication‐assisted exfoliation of polygrained icosahedral Al–Pd–Mn quasicrystals at room temperature shows the formation of a large area of mono‐ and few layers in threefold quasicrystalline plane. The formation of these layers from random grain orientation consistently indicates that the threefold plane is most stable in comparison to the twofold and fivefold planes in icosahedral clusters. The above experimental observations are further supported with help of theoretical simulations. The mono‐ and few‐layered aperiodic planes render plentiful active sites for the catalysis of hydrogen evolution reaction. The threefold 2D quasicrystalline plane exhibits a hydrogen evolution reaction overpotential of ≈100 mV (160 times less than bulk counterpart) and long‐term durability. These systems constitute the first demonstration of quasicrystalline monolayer ordering in a free‐standing thin layer without requiring the support of periodic or aperiodic substrate.
Azo Compounds Derived from Electrochemical Reduction of Nitro Compounds for High Performance Li‐Ion Batteries
Authors: Luo Chao , Ji Xiao , Hou Singyuk , Eidson Nico , Fan Xiulin , Liang Yujia , Deng Tao , Jiang Jianjun , Wang Chunsheng 
Published: April 2018

AbstractOrganic compounds are desirable alternatives for sustainable lithium‐ion battery electrodes. However, the electrochemical properties of state‐of‐the‐art organic electrodes are still worse than commercial inorganic counterparts. Here, a new chemistry is reported based on the electrochemical conversion of nitro compounds to azo compounds for high performance lithium‐ion batteries. 4‐Nitrobenzoic acid lithium salt (NBALS) is selected as a model nitro compound to systemically investigate the structure, lithiation/delithiation mechanism, and electrochemical performance of nitro compounds. NBALS delivers an initial capacity of 153 mAh g−1 at 0.5 C and retains a capacity of 131 mAh g−1 after 100 cycles. Detailed characterizations demonstrate that during initial electrochemical lithiation, the nitro group in crystalline NBALS is irreversibly reduced into an amorphous azo compound. Subsequently, the azo compound is reversibly lithiated/delithiated in the following charge/discharge cycles with high electrochemical performance. The lithiation/delithiation mechanism of azo compounds is also validated by directly using azo compounds as electrode materials, which exhibit similar electrochemical performance to nitro compounds, while having a much higher initial Coulombic efficiency. Therefore, this work proves that nitro compounds can be electrochemically converted to azo compounds for high performance lithium‐ion batteries.
Low‐Saturation‐Intensity, High‐Photostability, and High‐Resolution STED Nanoscopy Assisted by CsPbBr3 Quantum Dots
Authors: Ye Shuai , Yan Wei , Zhao Mengjie , Peng Xiao , Song Jun , Qu Junle 
Published: April 2018

AbstractStimulated emission depletion (STED) nanoscopy is one of the most promising super‐resolution imaging techniques for microstructure imaging. Commercial CdSe@ZnS quantum dots are used as STED probes and ≈50 nm lateral resolution is obtained. Compared with other quantum dots, perovskite CsPbBr3 nanoparticles (NPs) possess higher photoluminescence quantum yield and larger absorption cross‐section, making them a more effective probe for STED nanoscopy. In this study, CsPbBr3 NPs are used as probes for STED nanoscopy imaging. The fluorescence intensity of the CsPbBr3 sample is hardly weakened at all after 200 min irradiation with a 39.8 mW depletion laser, indicating excellent photobleaching resistance of the CsPbBr3 NPs. The saturation intensity of the CsPbBr3 NPs is extremely low and estimated to be only 0.4 mW (0.126 MW cm−2). Finally, an ultrahigh lateral resolution of 20.6 nm is obtained for a single nanoparticle under 27.5 mW STED laser irradiation in CsPbBr3‐based STED nanoscopy imaging, which is a tenfold improvement compared with confocal microscopy. Because of its high fluorescence stability and ultrahigh resolution under lower depletion power, CsPbBr3‐assisted STED nanoscopy has great potential to investigate microstructures that require super‐resolution and long‐term imaging.
Intravenous thrombolysis in unwitnessed stroke onset: MR WITNESS trial results
Authors: Schwamm Lee H. , Wu Ona , Song Shlee S. , Latour Lawrence L. , Ford Andria L. , Hsia Amie W. , Muzikansky Alona , Betensky Rebecca A. , Yoo Albert J. , Lev Michael H. , Boulouis Gregoire , Lauer Arne , Cougo Pedro , Copen William A. , Harris Gordon J. , Warach Steven ,   on behalf of the MR WITNESS Investigators
Published: April 2018

ObjectiveMost acute ischemic stroke (AIS) patients with unwitnessed symptom onset are ineligible for intravenous thrombolysis due to timing alone. Lesion evolution on fluid‐attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) correlates with stroke duration, and quantitative mismatch of diffusion‐weighted MRI with FLAIR (qDFM) might indicate stroke duration within guideline‐recommended thrombolysis. We tested whether intravenous thrombolysis ≤4.5 hours from the time of symptom discovery is safe in patients with qDFM in an open‐label, phase 2a, prospective study (NCT01282242).MethodsPatients aged 18 to 85 years with AIS of unwitnessed onset at 4.5 to 24 hours since they were last known to be well, treatable within 4.5 hours of symptom discovery with intravenous alteplase (0.9mg/kg), and presenting with qDFM were screened across 14 hospitals. The primary outcome was the risk of symptomatic intracranial hemorrhage (sICH) with preplanned stopping rules. Secondary outcomes included symptomatic brain edema risk, and functional outcomes of 90‐day modified Rankin Scale (mRS).ResultsEighty subjects were enrolled between January 31, 2011 and October 4, 2015 and treated with alteplase at median 11.2 hours (IQR = 9.5–13.3) from when they were last known to be well. There was 1 sICH (1.3%) and 3 cases of symptomatic edema (3.8%). At 90 days, 39% of subjects achieved mRS = 0–1, as did 48% of subjects who had vessel imaging and were without large vessel occlusions.InterpretationIntravenous thrombolysis within 4.5 hours of symptom discovery in patients with unwitnessed stroke selected by qDFM, who are beyond the recommended time windows, is safe. A randomized trial testing efficacy using qDFM appears feasible and is warranted in patients without large vessel occlusions. Ann Neurol 2018;83:980–993
Stabilized Vanadium Catalyst for Olefin Polymerization by Site Isolation in a Metal–Organic Framework
Authors: Comito Robert J. , Wu Zhenwei , Zhang Guanghui , Lawrence John A. , Korzyński Maciej D. , Kehl Jeffrey A. , Miller Jeffrey T. , Dincă Mircea 
Published: April 2018

AbstractVanadium catalysts offer unique selectivity in olefin polymerization, yet are underutilized industrially owing to their poor stability and productivity. Reported here is the immobilization of vanadium by cation exchange in MFU‐4l, thus providing a metal–organic framework (MOF) with vanadium in a molecule‐like coordination environment. This material forms a single‐site heterogeneous catalyst with methylaluminoxane and provides polyethylene with low polydispersity (PDI≈3) and the highest activity (up to 148 000 h−1) reported for a MOF‐based polymerization catalyst. Furthermore, polyethylene is obtained as a free‐flowing powder as desired industrially. Finally, the catalyst shows good structural integrity and retains polymerization activity for over 24 hours, both promising attributes for the commercialization of vanadium‐based polyolefins.
Establishment and characterization of a primary murine adipose tissue‐chip
Authors: Tanataweethum Nida , Zelaya Adelyn , Yang Feipeng , Cohen Ronald N. , Brey Eric M. , Bhushan Abhinav 
Published: April 2018

AbstractBetter experimental models are needed to enhance our understanding of metabolic regulation which is seen in obesity and metabolic disorders, such as type 2 diabetes. In vitro models based on microfluidics enable physiological representations of tissues with several advantages over conventional culture systems, such as perfused flow to better mimic the physiological environment. Although cell lines such as 3T3‐L1 have been incorporated in microfluidic devices, murine primary preadipocytes have not been differentiated and maintained for long‐term monitoring in these culture systems. We describe the differentiation of these cells into white adipose depots on a perfused microfluidic chip. We compare the effects of shear flow on these cells, and show with a direct comparison of high/low shear conditions that direct shear is detrimental to the viability of preadipocytes. We further develop a dual‐chamber microfluidic chip that enables perfusion while at the same time protects the cells from direct fluidic shear. We show that the dual‐layer microfluidic device enables long‐term culture of cells and allows stimulation of cells through perfusion—we can culture, differentiate, and maintain the differentiated adipose tissue for over multiple weeks in the device. Both triglycerides and lipolytic glycerol production increased significantly by several folds during differentiation. After successful differentiation, the adipocytes had upregulated expression of leptin and adiponectin, which are important makers of the final stage of adipogenic differentiation. In conclusion, the dual‐layer microfluidic device incorporated with primary adipocytes improves the understanding of adipose differentiation under dynamic conditions and is positioned to serve as a disease model for studying obesity and other metabolic disorders.
Sulfur Microspheres Encapsulated in Porous Silver‐Based Shell with Superior Performance for Lithium‐Sulfur Batteries
Authors: Mo Yu‐Xue , Jiang You‐Hong , Lin Jin‐Xia , Zhou Yao , Li Jun‐Tao , Wu Qi‐Hui , Huang Ling , Liao Hong‐Gang , Sun Shi‐Gang 
Published: April 2018

AbstractThe lithium‐sulfur system is considered as one of the next‐generation batteries owing to its low‐cost and high theoretical energy density. However, the poor conductivity of sulfur, undesirable dissolution, and shuttling of lithium polysulfides are still main challenges for a practical application. Herein, a chemical plating method was developed to encapsulate sulfur microspheres within a porous Ag‐based thin shell of ca. 67 nm in thickness (denoted as S@Ag microcomposites). The sulfur content in the S@Ag particles is 89 wt%. With such structural and compositional merits, the core‐shell composites can effectively facilitate the electron transfer and alleviate the polysulfide dissolution. When utilized as cathode in Li−S batteries, the S@Ag microcomposites exhibit good electrochemical performance, featured by an initial charge capacity of 1231 mAh g−1 and a capacity of 922 mAh g−1 after 100 cycles at 0.2 C. The electrochemical performance of commercial S particles was also improved after treated by this chemical plating method. This study provides a simple and novel approach to fabricate S composite cathodes with high S content and promising electrochemical properties.
N4‐Tetradentate Chelators Efficiently Regulate Copper Homeostasis and Prevent ROS Production Induced by Copper‐Amyloid‐β1–16
Authors: Zhang Weixin , Liu Yan , Hureau Christelle , Robert Anne , Meunier Bernard 
Published: April 2018

AbstractThe disruption of copper homeostasis and the oxidative stress induced by Cu‐amyloids are crucial features of Alzheimer's disease pathology. The copper specific N4‐tetradendate ligands TDMQ20 and 1 are able to fully inhibit in vitro the aerobic oxidation of ascorbate induced by Cu‐Aβ1‐16, even in the presence of 100 molar equivalents of ZnII with respect to CuII, whereas other ligands with N2O2 or N3O2 coordination spheres failed to do so. This essential result indicates that, in addition to metal selectivity, the coordination sphere of copper chelators should exhibit a N4‐tetradendate motif to be able to reduce an oxidative stress in the zinc‐rich physiological environment of brain. The N4‐scaffolds of these two aminoquinoline‐based ligands, TDMQ20 or 1, suitable for a square‐planar coordination of copper(II), allowed them to enhance both the selectivity for copper and the ability to reduce the oxidative stress induced by copper‐amyloid in a zinc‐rich environment.
Synthesis of O6‐Corona[3]arene[3]pyridazines and Their Molecular Recognition Property in Organic and Aqueous Media
Authors: Lu Yao , Liang Dong‐Dong , Fu Zhan‐Da , Guo Qing‐Hui , Wang Mei‐Xiang 
Published: April 2018

AbstractO6‐Corona[3]arene[3]pyridazines were synthesized from the one‐pot macrocyclic condensation reaction of 3,6‐dichlorotetrazine with 1,4‐dihydroquinone derivatives followed by the inverse electron demand Diels‐Alder reaction of the tetrazine rings with a cyclopentanone‐derived enamine. Conversion of six ester groups within macrocycle into all sodium acetate moieties afforded a water soluble O6‐corona[3]arene[3]pyridazine. The coronary macrocycle host formed complexes selectively with organic ammoniums and dinitrile guests in a 1: 1 stoichiometric ratio in organic solvents with association constants ranging from (2.96 ± 0.10) × 101 to (2.53 ± 0.33) × 105 L·mol−1. Water soluble O6‐corona[3]arene[3]pyridazine was also able to complex strongly with organic ammoniums in water to give an association constant up to (2.67 ± 0.21) × 104 L·mol−1. The pseudo‐rotaxane and inclusion structures of the host‐guest complexes were revealed by the X‐ray crystallography.
Improving semantic similarity retrieval with word embeddings
Authors: Yan Fengqi , Fan Qiaoqing , Lu Mingming 
Published: April 2018

SummaryWord similarity matchmaking is one of the core research areas of information retrieval. The existing methods based on a synonym dictionary would lead to the problem of semantic gap, which could be caused by the absence of synonyms. To address this problem, we improve semantic similarity retrieval by incorporating word embeddings. Especially, word embeddings are trained by Word2Vec and then use them to depict the semantic similarity between words. Experiments are conducted on two different datasets, ie, one is a public long text dataset (ie, Reuters‐21578), and the other is a short text dataset (ie, 120ask) collected from a healthcare community. The experimental results on the two datasets show that the proposed method further improves the accuracy of the similarity retrieval.
Role of Hydrogen‐Bond Interactions in CO2 Capture by Wet Phosphonium Formate Ionic Liquid: A Raman Spectroscopic Study
Authors: Yasaka Yoshiro , Saito Yuma , Kimura Yoshifumi 
Published: April 2018

AbstractThe mechanism of CO2 absorption by a formate ionic liquid, [P4444]HCOO, was studied by Raman spectroscopy. The band area for the symmetric CO2 stretching of the formate anion linearly decreases with the CO2 loading. From the slope of the decrease, 1 : 1 stoichiometry is proven between CO2 and the formate anion. The result favors the mechanism we proposed in a preceding work [J. Chem. Eng. Data 61, 837 (2016)]: HCOO−+CO2+H2O→HCOOH+HCO3−→[HCOOH…HCO3−]. Further support for the mechanism is obtained by the observation of antisymmetric vibration of CO for the proposed hydrogen‐bonded complex between HCOOH and HCO3−. The bands appeared as a doublet (1677 and 1730 cm−1) as this complex has two carbonyl groups. Based on DFT calculations, the [HCOOH…HCO3−] complex is supposed to be the most abundant form of chemisorbed CO2.
One‐Dimensional ABX3‐Type Fluorescent Crystal: CH3NH3ZnI3
Authors: Wei Hao , Zhang Liuqi , Wang Jilin , Chen Jian , Zheng Guoyuan , Long Fei , Zou Zhengguang , Gao Yihua 
Published: April 2018

AbstractThe ABX3‐type organic‐inorganic hybrid compound CH3NH3ZnI3 is grown by a liquid diffusion method in methylbenzene solution for the first time. The as prepared samples are characterized by single crystal diffraction, XRD, Infrared (IR) and Raman spectra, TG, UV‐Vis and PL respectively. The results indicate that CH3NH3ZnI3 crystal is demonstrated a monoclinic system with the space group P21/n at room temperature. And the sample presents relatively good thermal stability until 270 °C and wide band gap of about 3.88 eV. Besides, when the crystal is excited at 330 nm in the PL characterization, it could exhibit a green fluorescence emission band a maximum value at 521 nm. Therefore, this kind of ABX3‐type organic‐inorganic hybrid compound will be a promising candidate for optical and electronic applications.
Neutral Red and Ferroin as Reversible and Rapid Redox Materials for Redox Flow Batteries
Authors: Hong Jeehoon , Kim Ketack 
Published: April 2018

AbstractNeutral red and ferroin are used as redox indicators (RINs) in potentiometric titrations. The rapid response and reversibility that are prerequisites for RINs are also desirable properties for the active materials in redox flow batteries (RFBs). This study describes the electrochemical properties of ferroin and neutral red as a redox pair. The rapid reaction rates of the RINs allow a cell to run at a rate of 4 C with 89 % capacity retention after the 100th cycle. The diffusion coefficients, electrode reaction rates, and solubilities of the RINs were determined. The electron‐transfer rate constants of ferroin and neutral red are 0.11 and 0.027 cm s−1, respectively, which are greater than those of the components of all‐vanadium and Zn/Br2 cells.
Trellis code‐aided high‐rate M‐QAM space‐time labeling diversity using a unitary expansion
Authors: Dlodlo Buthanani , Xu Hongjun 
Published: April 2018

SummaryIn this paper, we present a high‐rate M‐ary quadrature amplitude modulation (M‐QAM) space‐time labeling diversity (STLD) system that retains the robust error performance of the conventional STLD system. The high‐rate STLD is realised by expanding the conventional STLD via a unitary matrix transformation. Robust error performance of the high‐rate STLD is achieved by incorporating trellis coding into the mapping of additional bits to high‐rate codes. The comparison of spectral efficiency between the proposed trellis code‐aided high‐rate STLD (TC‐STLD) and the conventional STLD shows that TC‐STLD with 16‐QAM and 64‐QAM respectively achieves a 12.5% and 8.3% increase in spectral efficiency for each additional bit sent with the transmitted high‐rate codeword. Moreover, we derive an analytical bound to predict the average bit error probability performance of TC‐STLD over Rayleigh frequency‐flat fading channels. The analytical results are verified by Monte Carlo simulation results, which show that the derived analytical bounds closely predict the average bit error probability performance at high signal‐to‐noise ratios (SNR). Simulation results also show that TC‐STLD with 1 additional bit achieves an insignificant SNR gain of approximately 0.05 dB over the conventional STLD, while TC‐STLD with 2 additional bits achieves an SNR gain of approximately 0.12 dB.
Habitat assessment of Marco Polo sheep (Ovis ammon polii) in Eastern Tajikistan: Modeling the effects of climate change
Authors: Salas Eric Ariel L. , Valdez Raul , Michel Stefan , Boykin Kenneth G. 
Published: April 2018

AbstractIdentifying the factors predicting the high‐elevation suitable habitats of Central Asian argali wild sheep and how these suitable habitats are affected by the changing climate regimes could help address conservation and management efforts and identify future critical habitat for the species in eastern Tajikistan. This study used environmental niche models (ENMs) to map and compare potential present and future distributions of suitable environmental conditions for Marco Polo argali. Argali occurrence points were collected during field surveys conducted from 2009 to 2016. Our models showed that terrain ruggedness and annual mean temperature had strong correlations on argali distribution. We then used two greenhouse gas concentration trajectories (RCP 4.5 and RCP 8.5) for two future time periods (2050 and 2070) to model the impacts of climate change on Marco Polo argali habitat. Results indicated a decline of suitable habitat with majority of losses observed at lower elevations (3,300–4,300 m). Models that considered all variables (climatic and nonclimatic) predicted losses of present suitable areas of 60.6% (6,928 km2) and 63.2% (7,219 km2) by 2050 and 2070, respectively. Results also showed averaged habitat gains of 46.2% (6,106 km2) at much higher elevations (4,500–6,900 m) and that elevational shifts of habitat use could occur in the future. Our results could provide information for conservation planning for this near threatened species in the region.
Strong associations between plant genotypes and bacterial communities in a natural salt marsh
Authors: Zogg Gregory P. , Travis Steven E. , Brazeau Daniel A. 
Published: April 2018

AbstractAlthough microbial communities have been shown to vary among plant genotypes in a number of experiments in terrestrial ecosystems, relatively little is known about this relationship under natural conditions and outside of select model systems. We reasoned that a salt marsh ecosystem, which is characterized by twice‐daily flooding by tides, would serve as a particularly conservative test of the strength of plant–microbial associations, given the high degree of abiotic regulation of microbial community assembly resulting from alternating periods of inundation and exposure. Within a salt marsh in the northeastern United States, we characterized genotypes of the foundational plant Spartina alterniflora using microsatellite markers, and bacterial metagenomes within marsh soil based on pyrosequencing. We found significant differences in bacterial community composition and diversity between bulk and rhizosphere soil, and that the structure of rhizosphere communities varied depending on the growth form of, and genetic variation within, the foundational plant S. alterniflora. Our results indicate that there are strong plant–microbial associations within a natural salt marsh, thereby contributing to a growing body of evidence for a relationship between plant genotypes and microbial communities from terrestrial ecosystems and suggest that principles of community genetics apply to this wetland type.