bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microfluidic Gel Patterning Method by Use of a Temporary Membrane for Organ‐On‐Chip Applications
Authors: Tibbe Martijn P. , Leferink Anne M. , van den Berg Albert , Eijkel Jan C. T. , Segerink Loes I. 
Published: January 2018

AbstractOrgan‐on‐chip systems promise to be useful tools for disease modeling and drug testing. These systems focus on the separation of the parenchymal tissue from endothelial cells, which form the vasculature. Previous organ‐on‐chip models make use of artificial membranes to separate two fluidic channels representing the parenchymal and the endothelial side of native barriers. However, artificial membranes disallow close cell association. During this study, a microfluidic chip, in which a temporary chitosan‐based membrane can be formed, is developed, making direct cell–cell contact between multiple cell types possible. This cell–cell contact on chip can be used to study the behavior of the blood–brain barrier. Chitosan is a polysaccharide that forms a gel‐like solid upon deprotonation. By creating an interface between a basic buffer solution and an acidic chitosan solution, the chitosan gets deprotonated at the interface forming a membrane in the chip. This membrane can be used as a physical barrier for cell culture. 24 h after cell seeding, the temporary membrane of chitosan can be removed by flushing an acidic solution through one of the channels. The membrane fabrication and removal method demonstrated here can be used to create membrane‐free cocultures in a microfluidic device for organs‐on‐chip research.
High‐Performance All‐Aryl Phenazasilines via Metal‐Free Radical‐Mediated CH Silylation for Organic Light‐Emitting Diodes
Authors: Xu Shen , Li Huanhuan , Chen Runfeng , Chen Zhicai , Xu Lijia , Tang Yuting , Huang Wei 
Published: January 2018

AbstractHeteroatom‐containing organic molecules show a unique combination of properties for high‐performance optoelectronic applications. With both Si and N heteroatoms in an aromatic architecture, phenazasilines are promising for optoelectronic devices, except for their synthetic difficulties. Through a newly developed two‐step SiH/CH coupling silylation in a metal‐free intramolecular radical‐mediated catalysis mechanism, all‐aryl phenazasilines that can be hardly synthesized by previous methods are facilely prepared and found to have excellent optoelectronic properties with both high thermal stability and high solubility due to the effects of bulky diphenyl substituents on Si, which cannot only strengthen the intramolecular interactions but also alleviate the intermolecular packing of phenazasilines. Using these compounds as host materials, high device performance was achieved with external quantum efficiency up to 21.3% and very low efficiency roll‐off (1.4% at 1000 cd m−2), which are among the best of the recent reported results of blue phosphorescent organic light emitting diodes. This design strategy featuring rigid all‐aryl phenazasiline motifs and the metal‐free radical‐catalyzed synthetic methodology should be important in developing high‐performance multiheteroatom modified aromatic molecules for organic optoelectronics.
Characterization of HIF‐1α/Glycolysis Hyperactive Cell Population via Small‐Molecule‐Based Imaging of Mitochondrial Transporter Activity
Authors: Wang Yang , Liao Xingyun , Sun Jianguo , Yi Bin , Luo Shenglin , Liu Tao , Tan Xu , Liu Dengqun , Chen Zelin , Wang Xin , Shi Chunmeng 
Published: January 2018

AbstractThe characterization of cancer stem‐like cells (CSCs) has profound implications for elucidating cancer biology and developing treatment strategies. Although surface markers are already used to identify CSCs, the expression of these markers is controversially linked to the phenotypes in different types of tumors and does not represent all functionally relevant of CSCs. Very recently, hyperactive HIF‐1α/glycolysis metabolic pathway is recognized as a master regulator of CSCs. In this study, a near‐infrared fluorescent small‐molecule, IR‐780, is identified for the exclusive characterization of human CSCs through the HIF‐1α/glycolysis dependent mitochondrial transporter ABCB10's activity. The results identified for the first time that ABCB10 is involved in the preferential uptake of IR‐780 in CSCs, which is regulated by HIF‐1α via the direct interaction with the binding site of ABCB10 gene promoter region. In addition, IR‐780 is demonstrated to conjugate with anticancer drug 5‐fluorouracil to act as a potential drug delivery carrier for CSC‐targeted therapy. Thus, the studies provide a new rational approach independent of surface markers to characterize CSCs via small‐molecule‐based imaging of HIF‐1α/glycolysis hyperactive metabolic pathway dependent mitochondrial transporter's activity, which holds promise for the further development of CSCs targeted diagnostic and therapeutic strategies.
Enhanced Ion Conductivity in Conducting Polymer Binder for High‐Performance Silicon Anodes in Advanced Lithium‐Ion Batteries
Authors: Zeng Wenwu , Wang Lei , Peng Xiang , Liu Tiefeng , Jiang Youyu , Qin Fei , Hu Lin , Chu Paul K. , Huo Kaifu , Zhou Yinhua 
Published: January 2018

AbstractPolymer binders with high ion and electron conductivities are prepared by assembling ionic polymers (polyethylene oxide and polyethylenimine) onto the electrically conducting polymer poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonate) chains. Crosslinking, chemical reductions, and electrostatics increase the modulus of the binders and maintain the integrity of the anode. The polymer binder shows lithium‐ion diffusivity and electron conductivity that are 14 and 90 times higher than those of the widely used carboxymethyl cellulose (with acetylene black) binder, respectively. The silicon anode with the polymer binder has a high reversible capacity of over 2000 mA h g−1 after 500 cycles at a current density of 1.0 A g−1 and maintains a superior capacity of 1500 mA h g−1 at a high current density of 8.0 A g−1.
Manganese‐Catalyzed C−H Cyanation of Arenes with N‐Cyano‐N‐(4‐methoxy)phenyl‐p‐toluenesulfonamide
Authors: Yu Xiaoqiang , Tang Jingjing , Jin Xinxin , Yamamoto Yoshinori , Bao Ming 
Published: January 2018

AbstractA manganese‐catalyzed C−H cyanation reaction of arenes has been developed using N‐cyano‐N‐(4‐methoxy)phenyl‐p‐toluenesulfonamide as the cyanating agent. The reaction proceeds smoothly with high regioselectivity to provide monocyanated products in satisfactory yields.
Metal‐Free Azidoarylation of Vinylcyclopropanes for the Synthesis of N3‐Containing Dihydronaphthalenes
Authors: Li Zong‐Rui , Wu Dun‐Qi , Sun Jian , Shen Jing , Deng Qing‐Hai 
Published: January 2018

AbstractAn efficient methodology for the direct metal‐free azidoarylation of vinylcyclopropanes using trimethylsilyl azide as the N3‐transfer reagent is described. The reaction can be performed on a gram scale and a series of N3‐containing dihydronaphthalene derivatives (20 examples) were prepared in good to high yields under mild reaction conditions. Furthermore, three of these organic azides were selected for facile conversion into the corresponding 1,2,3‐triazoles or amino derivatives.
Lewis‐Acid‐Catalyzed Activation of Zerumbone towards Sesquiterpenoid Derivatives: Sustainable Utilization of Abundant Natural Resources for the Synthesis of Chemically Diverse Architectures
Authors: Dhanya Bhandara Purayil , Gopalan Greeshma , Sasikumar Parameswaran , Neethu Sivadas , Meenu Murugan Thulasi , Sharathna Puthiyaparambath , John Jubi , Varughese Sunil , Sabu Mamiyil , Dan Mathew , Radhakrishnan Kokkuvayil Vasu 
Published: January 2018

AbstractA facile Lewis‐acid‐catalyzed method for the synthesis of structurally diverse sesquiterpenoid derivatives from readily available and abundant 11‐membered natural product zerumbone has been developed. Starting from zerumbone, we have developed an efficient cyclization process for the creation of [5.7], [5.8], and [5.8.3] fused‐ring systems. This process was exemplified by the selective functionalization of zerumbone; by controlling the conformation of the 11‐membered ring, the ring‐closing process could be tuned to afford the fused‐ring system of choice.
Submucosal gland mucus strand velocity is decreased in chronic rhinosinusitis
Authors: Tipirneni Kiranya E. , Zhang Shaoyan , Cho Do‐Yeon , Grayson Jessica , Skinner Daniel F. , Mackey Calvin , Moore Lindsay , Cole Denzel , Banks Catherine G. , Woodworth Bradford A. 
Published: January 2018

BackgroundChronic rhinosinusitis (CRS) may be initiated by innately impaired host defense mechanisms that predispose the upper airways to infection. Recent evidence suggests tethering of submucosal gland mucus strands represents an inciting event within cystic fibrosis (CF) airways, occurring prior to onset of chronic infection. Submucosal gland hypertrophy and defective mucociliary clearance (MCC) are present in actively inflamed sinuses, but mucus strand velocity may also be affected as a secondary event, further contributing to chronic disease. The objective of this study is to assess whether mucus strand velocity is decreased in patients with CRS.MethodsMucosal explants from patients with and without CRS were submerged in Ringer's solution mixed with fluorescent nanospheres. Methacholine was then added, and videos demonstrating strand growth and detachment were generated from a time‐lapse of Z‐stack images using a multiphoton confocal microscope. Dynamic mucus strands were identified and individual velocities quantified with the MTrackJ plug‐in of ImageJ.ResultsFifteen patients met criteria for ex vivo analysis of mucus strand velocities (CRS, n = 9 vs controls, n = 6). Mucus strands were recorded (pixels/second) streaming from the submucosal gland openings. Average mucus strand velocities were significantly decreased in patients with CRS (1.53 ± 0.67 vs controls, 4.86 ± 1.68 pixels/second; p < 0.001).ConclusionThis study is the first to report evidence of abnormal mucus strand velocity from submucosal glands in diseased sinonasal mucosa. Future pharmacologic studies targeting this critical component of MCC are warranted.
Interconversion of Molybdenum Imido and Amido Complexes by Proton‐Coupled Electron Transfer
Authors: Bezdek Máté J. , Chirik Paul J. 
Published: January 2018

AbstractInterconversion of the molybdenum amido [(PhTpy)(PPh2Me)2Mo(NHtBuAr)][BArF24] (PhTpy=4′‐Ph‐2,2′,6′,2“‐terpyridine; tBuAr=4‐tert‐butyl‐C6H4; ArF24=(C6H3‐3,5‐(CF3)2)4) and imido [(PhTpy)(PPh2Me)2Mo(NtBuAr)][BArF24] complexes has been accomplished by proton‐coupled electron transfer. The 2,4,6‐tri‐tert‐butylphenoxyl radical was used as an oxidant and the non‐classical ammine complex [(PhTpy)(PPh2Me)2Mo(NH3)][BArF24] as the reductant. The N−H bond dissociation free energy (BDFE) of the amido N−H bond formed and cleaved in the sequence was experimentally bracketed between 45.8 and 52.3 kcal mol−1, in agreement with a DFT‐computed value of 48 kcal mol−1. The N−H BDFE in combination with electrochemical data eliminate proton transfer as the first step in the N−H bond‐forming sequence and favor initial electron transfer or concerted pathways.
Asymmetric Catalytic Preparation of Polysubstituted Cyclopropanol and Cyclopropylamine Derivatives
Authors: Simaan Marwan , Marek Ilan 
Published: January 2018

AbstractThe catalytic asymmetric carbometalation of cyclopropenes followed by either an electrophilic oxidation or amination reaction provides a unique approach to the formation of diastereomerically pure and enantiomerically enriched cyclopropanol and cyclopropylamine derivatives, respectively.
Barbier–Negishi Coupling of Secondary Alkyl Bromides with Aryl and Alkenyl Triflates and Nonaflates
Authors: Zhang Ke‐Feng , Christoffel Fadri , Baudoin Olivier 
Published: January 2018

AbstractA mild and practical Barbier–Negishi coupling of secondary alkyl bromides with aryl and alkenyl triflates and nonaflates has been developed. This challenging reaction was enabled by the use of a very bulky imidazole‐based phosphine ligand, which resulted in good yields as well as good chemo‐ and site selectivities for a broad range of substrates at room temperature and under non‐aqueous conditions. This reaction was extended to primary alkyl bromides by using an analogous pyrazole‐based ligand.
Molecular‐Barrier‐Enhanced Aromatic Fluorophores in Cocrystals with Unity Quantum Efficiency
Authors: Ye Huanqing , Liu Guangfeng , Liu Sheng , Casanova David , Ye Xin , Tao Xutang , Zhang Qichun , Xiong Qihua 
Published: January 2018

AbstractSinglet–triplet conversion in organic light‐emitting materials introduces non‐emissive (dark) and long‐lived triplet states, which represents a significant challenge in constraining the optical properties. There have been considerable attempts at separating singlets and triplets in long‐chain polymers, scavenging triplets, and quenching triplets with heavy metals; nonetheless, such triplet‐induced loss cannot be fully eliminated. Herein, a new strategy of crafting a periodic molecular barrier into the π‐conjugated matrices of organic aromatic fluorophores is reported. The molecular barriers effectively block the singlet‐to‐triplet pathway, resulting in near‐unity photoluminescence quantum efficiency (PLQE) of the organic fluorophores. The transient optical spectroscopy measurements confirm the absence of the triplet absorption. These studies provide a general approach to preventing the formation of dark triplet states in organic semiconductors and bring new opportunities for the development of advanced organic optics and photonics.
Enantioselective Polyene Cyclization Catalyzed by a Chiral Brønsted Acid
Authors: Fan Liwen , Han Chunyu , Li Xuerong , Yao Jiasheng , Wang Zhengning , Yao Chaochao , Chen Weihao , Wang Tao , Zhao Junfeng 
Published: January 2018

AbstractThe first enantioselective polyene cyclization initiated by a BINOL‐derived chiral N‐phosphoramide (NPA) catalyzed protonation of an imine is described. The ion‐pair formed between the iminium ion and chiral counter anion of the NPA plays an important role for controlling the stereochemistry of the overall transformation. This strategy offers a highly efficient approach to fused tricyclic frameworks containing three contiguous stereocenters, which are widely found in natural products. In addition, the first catalytic asymmetric total synthesis of (−)‐ferruginol was accomplished with an NPA catalyzed enantioselective polyene cyclization, as the key step for the construction of the tricyclic core, with excellent yield and enantioselectivity.
Disilenyl Silylene Reactivity of a Cyclotrisilene
Authors: Zhao Hui , Leszczyńska Kinga , Klemmer Lukas , Huch Volker , Zimmer Michael , Scheschkewitz David 
Published: January 2018

AbstractThe highly reactive silicon congeners of cyclopropene, cyclotrisilenes (c‐Si3R4), typically undergo either π‐addition to the Si=Si double bond or σ‐insertion into the Si−Si single bond. In contrast, treatment of c‐Si3Tip4 (Tip=2,4,6‐iPr3C6H2) with styrene and benzil results in ring opening of the three‐membered ring to formally yield the [1+2]‐ and [1+4] cycloaddition product of the isomeric disilenyl silylene to the C=C bond and the 1,2‐diketone π system, respectively. At elevated temperature, styrene is released from the [1+2]‐addition product leading to the thermodynamically favored housane species after [2+2] cycloaddition of styrene and c‐Si3Tip4.
Stable trans isomer as the kinetic and theromodynamic product for the oxidative addition of MeI to cycloplatinated(II) complexes comprising isocyanide ligands
Authors: Shahsavari Hamid R. , Aghakhanpour Reza Babadi , Hossein‐Abadi Mojdeh , Kia Reza , Raithby Paul R. 
Published: January 2018

The present investigation introduces a new series of cycloplatinated(II) complexes, with the general formula Pt(O‐bpy)(Me)(CN‐R)] (R = benzyl, 2‐naphtyl and tert‐butyl), which are able to generate the stable trans‐Pt(IV) product in the solution after the reaction with iodomethane. In fact, the trans product is both the kinetic and thermodynamic product of the reaction; this observation was supported by DFT calculations. These Pt(II) complexes are supported by 2,2'‐bipyridine N‐oxide (O‐bpy) and one of several isocyanides as the cyclometalated and ancillary ligands, respectively. These new Pt(II) complexes undergo oxidative addition with MeI to give the corresponding trans‐Pt(IV) complexes. All the complexes were identified employing the multi‐nuclear NMR spectroscopy and single crystal X‐ray crystallography. The kinetic investigations were also performed for the oxidative addition reactions in order to measure the reaction rates; the reaction was followed by UV‐Vis spectroscopy. The rates obtained follow the trend CN‐tBu > CN‐Bz > CN‐2 Np for the CN‐R ligands in the Pt(II) complexes. The order can be related to the degree of electron‐donation of the R group (tert‐butyl > benzyl > 2‐naphtyl).
Nitrogen‐doped graphene as an alternative to ecotoxic zinc oxide in rubbers
Authors: Glebova Yulia , Severin Nikolai , Shershnev Vladimir , Rabe Jürgen P. 
Published: January 2018

ABSTRACTZinc oxide (ZnO) is an essential ingredient in industrial rubber production; it regulates the onset of vulcanization, accelerates the kinetics of vulcanization, and improves the mechanical properties of rubber. However, environmental pollution with ZnO is a concern because it is recognized to be significantly ecotoxic and might also have adverse effects on human health. One of the major sources of ZnO environmental pollution is rubber items, tires in particular. Nitrogen (N)‐doped graphene is a promising next‐generation catalyst. We show here that the replacement of 3 phr ZnO by just 0.1 phr N‐doped graphene in styrene–butadiene rubber reduced the vulcanization onset time by more than a factor of two while retaining the fast vulcanization kinetics and enhancing the tensile strength in comparison with rubber with just ZnO. A shorter vulcanization time implies energy savings, which, together with the nontoxicity of N‐graphene, should make the resulting rubbers substantially more environmentally friendly. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46116.
Reconstruction of molecular network evolution from cross‐sectional omics data
Authors: Aflakparast Mehran , de Gunst Mathisca C. M. , van Wieringen Wessel N. 
Published: January 2018

AbstractCross‐sectional studies may shed light on the evolution of a disease like cancer through the comparison of patient traits among disease stages. This problem is especially challenging when a gene–gene interaction network needs to be reconstructed from omics data, and, in addition, the patients of each stage need not form a homogeneous group. Here, the problem is operationalized as the estimation of stage‐wise mixtures of Gaussian graphical models (GGMs) from high‐dimensional data. These mixtures are fitted by a (fused) ridge penalized EM algorithm. The fused ridge penalty shrinks GGMs of contiguous stages. The (fused) ridge penalty parameters are chosen through cross‐validation. The proposed estimation procedures are shown to be consistent and their performance in other respects is studied in simulation. The down‐stream exploitation of the fitted GGMs is outlined. In a data illustration the methodology is employed to identify gene–gene interaction network changes in the transition from normal to cancer prostate tissue.
Effect of CaCN2 on the preparation of CaAlSiN3:Eu2+ phosphors
Authors: Xiao Lin‐Jiu , Lv Yan , Xie Ying , Su Jian , Jiang Xin‐Dong , He Ming‐rui 
Published: January 2018

AbstractHighly efficient red‐emitting phosphors, CaAlSiN3:Eu2+, were successfully prepared by the solid‐state method using calcium cyanide (CaCN2) as the single calcium source.The influences of crystallization temperature, crystallization time, calcination mode and compounds ratio on the photoluminescent properties were investigated. The CaAlSiN3:Eu2+ phosphors were obtained with 1 mol% CaCN2 by a two‐step calcination procedure at 900°C for 2 h and subsequently at 1600°C for 8 h. The CaAlSiN3:Eu2+ phosphors showed the strongest luminescent intensity at 660 nm when excited by 468 nm. With an increase in crystallization time, the maximum wavelength of the emission was shifted from 644 nm to 660 nm.
Selective production of decanoic acid from iterative reversal of β‐oxidation pathway
Authors: Kim Seohyoung , Gonzalez Ramon 
Published: January 2018

AbstractDecanoic acid is a valuable compound used as precursor for industrial chemicals, pharmaceuticals, and biofuels. Despite efforts to produce it from renewables, only limited achievements have been reported. Here, we report an engineered cell factory able to produce decanoic acid as a major product from glycerol, and abundant and renewable feedstock. We exploit the overlapping chain‐length specificity of β‐oxidation reversal (r‐BOX) and thioesterase enzymes to selectively generate decanoic acid. This was achieved by selecting r‐BOX enzymes that support the synthesis of acyl‐CoA of up to 10 carbons (thiolase BktB and enoyl‐CoA reductase EgTER) and a thioesterase that exhibited high activity toward decanoyl‐CoA and longer‐chain acyl‐CoAs (FadM). Combined chromosomal and episomal expression of r‐BOX core enzymes such as enoyl‐CoA reductase and thiolase (in the presence of E. coli thioesterase FadM) increased titer and yield of decanoic acid, respectively. The carbon flux toward decanoic acid was substantially increased by the use of an organic overlay, which decreased its intracellular accumulation and presumably increased its concentration gradient across cell membrane, suggesting that decanoic acid transport to the extracellular medium might be a major bottleneck. When cultivated in the presence of a n‐dodecane overlay, the final engineered strain produced 2.1 g/L of decanoic acid with a yield of 0.1 g/g glycerol. Collectively, our data suggests that r‐BOX can be used as a platform to selectively produce decanoic acid and its derivatives at high yield, titer and productivity.
The synergistic role of ATP‐dependent drug efflux pump and focal adhesion signaling pathways in vinorelbine resistance in lung cancer
Authors: Nakanishi Takao , Menju Toshi , Nishikawa Shigeto , Takahashi Koji , Miyata Ryo , Shikuma Kei , Sowa Terumasa , Imamura Naoto , Hamaji Masatsugu , Motoyama Hideki , Hijiya Kyoko , Aoyama Akihiro , Sato Toshihiko , Chen‐Yoshikawa Toyofumi F. , Sonobe Makoto , Date Hiroshi 
Published: January 2018

AbstractThe vinorelbine (VRB) plus cisplatin regimen is widely used to treat non–small cell lung cancer (NSCLC), but its cure rate is poor. Drug resistance is the primary driver of chemotherapeutic failure, and the causes of resistance remain unclear. By focusing on the focal adhesion (FA) pathway, we have highlighted a signaling pathway that promotes VRB resistance in lung cancer cells. First, we established VRB‐resistant (VR) lung cancer cells (NCI‐H1299 and A549) and examined its transcriptional changes, protein expressions, and activations. We treated VR cells by Src Family Kinase (SFK) inhibitors or gene silencing and examined cell viabilities. ATP‐binding Cassette Sub‐family B Member 1 (ABCB1) was highly expressed in VR cells. A pathway analysis and western blot analysis revealed the high expression of integrins β1 and β3 and the activation of FA pathway components, including Src family kinase (SFK) and AKT, in VR cells. SFK involvement in VRB resistance was confirmed by the recovery of VRB sensitivity in FYN knockdown A549 VR cells. Saracatinib, a dual inhibitor of SFK and ABCB1, had a synergistic effect with VRB in VR cells. In conclusion, ABCB1 is the primary cause of VRB resistance. Additionally, the FA pathway, particularly integrin, and SFK, are promising targets for VRB‐resistant lung cancer. Further studies are needed to identify clinically applicable target drugs and biomarkers that will improve disease prognoses and predict therapeutic efficacies.