bluuebunny/crossref_metadata_2025_split huggingface dataset:
hdac4 mediates perichondral ossification and pharyngeal skeleton development in the zebrafish
Authors: DeLaurier April , Alvarez Cynthia Lizzet , Wiggins Kali J 
Published: January 2019

Background
Histone deacetylases (HDACs) are epigenetic factors that function to repress gene transcription by removing acetyl groups from the N-terminal of histone lysines. Histone deacetylase 4 (HDAC4), a class IIa HDAC, has previously been shown to regulate the process of endochondral ossification in mice via repression of Myocyte enhancer factor 2c (MEF2C), a transcriptional activator of Runx2, which in turn promotes chondrocyte maturation and production of bone by osteoblasts.

Methods & Materials
In this study, we generated two zebrafish lines with mutations in hdac4 using CRISPR/Cas9 and analyzed mutants for skeletal phenotypes and expression of genes known to be affected by Hdac4 expression.

Results
Lines have insertions causing a frameshift in a proximal exon of hdac4 and a premature stop codon. Mutations are predicted to result in aberrant protein sequence and a truncated protein, eliminating the Mef2c binding domain and Hdac domain. Zygotic mutants from two separate lines show a significant increase in ossification of pharyngeal ceratohyal cartilages at 7 days post fertilization (dpf) (p < 0.01, p < 0.001). At 4 dpf, mutant larvae have a significant increase of expression of runx2a and runx2b in the ceratohyal cartilage (p < 0.05 and p < 0.01, respectively). A subset of maternal-zygotic (mz) mutant and heterozygote larvae (40%) have dramatically increased ossification at 7 dpf compared to zygotic mutants, including formation of a premature anguloarticular bone and mineralization of the first and second ceratobranchial cartilages and symplectic cartilages, which normally does not occur until fish are approximately 10 or 12 dpf. Some maternal-zygotic mutants and heterozygotes show loss of pharyngeal first arch elements (25.9% and 10.2%, respectively) and neurocranium defects (30.8% and 15.2%, respectively). Analysis of RNA-seq mRNA transcript levels and in situ hybridizations from zygotic stages to 75–90% epiboly indicates that hdac4 is highly expressed in early embryos, but diminishes by late epiboly, becoming expressed again in larval stages.

Discussion
Loss of function of hdac4 in zebrafish is associated with increased expression of runx2a and runx2b targets indicating that a role for hdac4 in zebrafish is to repress activation of ossification of cartilage. These findings are consistent with observations of precocious cartilage ossification in Hdac4 mutant mice, demonstrating that the function of Hdac4 in skeletal development is conserved among vertebrates. Expression of hdac4 mRNA in embryos younger than 256–512 cells indicates that there is a maternal contribution of hdac4 to the early embryo. The increase in ossification and profound loss of first pharyngeal arch elements and anterior neurocranium in a subset of maternal-zygotic mutant and heterozygote larvae suggests that maternal hdac4 functions in cartilage ossification and development of cranial neural crest-derived structures.
GeO2 Encapsulated Ge Nanostructure with Enhanced Lithium‐Storage Properties
Authors: Yan Shancheng , Song Haizeng , Lin Shuren , Wu Han , Shi Yi , Yao Jie 
Published: January 2019

AbstractGermanium (Ge)‐based nanostructures, especially those with germanium dioxide (GeO2), have drawn great interest for applications in lithium (Li)‐ion batteries due to their ultrahigh theoretical Li+ storage capability (8.4 Li/Ge). However, GeO2 in conventional Ge(s)/GeO2(c) (where (c) means the core and (s) means the shell) composite anodes with Ge shell outside GeO2 undergoes an irreversible conversion reaction, which restricts the maximum capacity of such batteries to 1126 mAhg−1 (the equivalent of storing 4.4 Li+). In this work, a porous GeO2(s)/Ge(c) nanostructure with GeO2 shell outside Ge cores are successfully fabricated utilizing the Kirkendall effect and used as a lithium‐ion battery anode, giving a substantially improved capacity of 1333.5 mAhg−1 at a current density of 0.1 Ag−1 after 30 cycles and a stable long‐time cycle performance after 100 cycles at a current density of 0.5 A g−1. The enhanced battery performance is attributed to the improved reversibility of GeO2 lithiation/delithiation processes catalyzed by Ge in the properly structured porous GeO2(s)/Ge(c) nanostructure.
Unraveling the Mechanobiology of the Immune System
Authors: Kim Jeong‐Ki , Shin Yu Jung , Ha Leslie Jaesun , Kim Deok‐Ho , Kim Dong‐Hwee 
Published: January 2019

AbstractCells respond and actively adapt to environmental cues in the form of mechanical stimuli. This extends to immune cells and their critical role in the maintenance of tissue homeostasis. Multiple recent studies have begun illuminating underlying mechanisms of mechanosensation in modulating immune cell phenotypes. Since the extracellular microenvironment is critical to modify cellular physiology that ultimately determines the functionality of the cell, understanding the interactions between immune cells and their microenvironment is necessary. This review focuses on mechanoregulation of immune responses mediated by macrophages, dendritic cells, and T cells, in the context of modern mechanobiology.
A UV‐Responsive Multifunctional Photoelectric Device Based on Discotic Columnar Nanostructures and Molecular Motors
Authors: Zou Cheng , Sun Jian , Wang Meng , Wang Jingxia , Wu Yuchen , Zhang Lanying , Zhu Zhongpeng , Xiong Guirong , Jiang Lei , Ikeda Tomiki , Yang Huai 
Published: January 2019

AbstractOrientation control of ordered materials would not only produce new physical phenomenon but also facilitate the development of fancy devices. Discotic liquid crystals (DLCs) form 1D charge transport pathway by self‐organizing into columnar nanostructures via π–π stacking. However, controlling the electrical properties in such nanostructures with some direct and instant way is a formidable task for their high viscosity and insensitivity to external stimuli. Herein, the arbitrary control over electrical conductivity of such columnar nanostructures is achieved with UV light by incorporating DLCs with molecular motors. Highly ordered DLC microstripe arrays are generated on desired substrate through a capillary bridge dewetting strategy. The conductivity of the microstripes could be continuously modulated by 365 nm light due to the influence of molecular motion under UV irradiation on the electron orbital overlap of columnar nanostructures. This is so because the disorder degree of the DLC molecules is associated with the intensity of UV light and the doping concentration of molecular motors. Moreover, the device shows memory effect and reversible conductivity change. The DLC microstripe arrays are very promising for the applications in UV detectors, memory devices, optical switches, and so on.
Revisiting the Buckling Metrology Method to Determine the Young's Modulus of 2D Materials
Authors: Iguiñiz Nestor , Frisenda Riccardo , Bratschitsch Rudolf , Castellanos‐Gomez Andres 
Published: January 2019

AbstractMeasuring the mechanical properties of 2D materials is a formidable task. While regular electrical and optical probing techniques are suitable even for atomically thin materials, conventional mechanical tests cannot be directly applied. Therefore, new mechanical testing techniques need to be developed. Up to now, the most widespread approaches require micro‐fabrication to create freely suspended membranes, rendering their implementation complex and costly. Here, a simple yet powerful technique is revisited to measure the mechanical properties of thin films. The buckling metrology method, that does not require the fabrication of freely suspended structures, is used to determine the Young's modulus of several transition metal dichalcogenides (MoS2, MoSe2, WS2, and WSe2) with thicknesses ranging from 2 to 10 layers. The obtained values for the Young's modulus and their uncertainty are critically compared with previously published results, finding that this simple technique provides results which are in good agreement with those reported using other highly sophisticated testing methods. By comparing the cost, complexity, and time required for the different methods reported in the literature, the buckling metrology method presents certain advantages that make it an interesting mechanical test tool for 2D materials.
Record‐High Superconductivity in Niobium–Titanium Alloy
Authors: Guo Jing , Lin Gongchang , Cai Shu , Xi Chuanying , Zhang Changjin , Sun Wanshuo , Wang Qiuliang , Yang Ke , Li Aiguo , Wu Qi , Zhang Yuheng , Xiang Tao , Cava Robert Joseph , Sun Liling 
Published: January 2019

AbstractThe extraordinary superconductivity has been observed in a pressurized commercial niobium–titanium alloy. Its zero‐resistance superconductivity persists from ambient pressure to the pressure as high as 261.7 GPa, a record‐high pressure up to which a known superconducting state can continuously survive. Remarkably, at such an ultra‐high pressure, although the ambient pressure volume is shrunk by 45% without structural phase transition, the superconducting transition temperature (TC) increases to ≈19.1 K from ≈9.6 K, and the critical magnetic field (HC2) at 1.8 K has been enhanced to 19 T from 15.4 T. These results set new records for both the TC and the HC2 among all the known alloy superconductors composed of only transition metal elements. The remarkable high‐pressure superconducting properties observed in the niobium–titanium alloy not only expand the knowledge on this important commercial superconductor but also are helpful for a better understanding on the superconducting mechanism.
Broncho‐Vaxom® (OM‐85 BV) soluble components stimulate sinonasal innate immunity
Authors: Triantafillou Vasiliki , Workman Alan D. , Patel Neil N. , Maina Ivy W. , Tong Charles C. L. , Kuan Edward C. , Kennedy David W. , Palmer James N. , Adappa Nithin D. , Waizel‐Haiat Salomon , Cohen Noam A. 
Published: January 2019

BackgroundBroncho‐Vaxom® (OM‐85 BV) is an extract of infectious respiratory bacteria that is used as an immunostimulant outside of the United States for the prevention and treatment of bronchitis and rhinosinusitis. Prior studies have shown that use of OM‐85 BV is associated with reduction in frequency of respiratory infection and decreased duration of antibiotic usage. However, the effects of OM‐85 BV on respiratory mucosal innate immunity are unknown.MethodsHuman sinonasal epithelial cells were grown at an air‐liquid interface (ALI). Ciliary beat frequency (CBF) and nitric oxide (NO) production in response to stimulation with OM‐85 BV was measured in vitro. Pharmacologic inhibitors of bitter taste receptor (T2R) signaling were used to determine if this pathway was taste‐receptor–mediated.ResultsApical application of OM‐85 BV resulted in an NO‐mediated increase in CBF (p < 0.05) and increased NO production (p < 0.0001) when compared to saline‐stimulated control cultures. ALI pretreatment with taste receptor pathway inhibitors blocked OM‐85 BV–induced increases in NO.ConclusionOM‐85 BV has ciliostimulatory and immunogenic properties that may be partially responsible for its observed efficacy as a respiratory therapeutic. These responses were NO‐dependent and consistent with T2R activation. Further work is necessary to elucidate specific component‐receptor signaling relationships.
Cobalt‐Catalyzed Intermolecular [2+2] Cycloaddition between Alkynes and Allenes
Authors: Ding Wei , Yoshikai Naohiko 
Published: January 2019

AbstractAn intermolecular [2+2] cycloaddition reaction between an alkyne and an allene is reported. In the presence of a cobalt(I)/diphosphine catalyst, a near equimolar mixture of the alkyne and allene is converted into a 3‐alkylidenecyclobutene derivative in good yield with high regioselectivity. The reaction tolerates a variety of internal alkynes and mono‐ or disubstituted allenes bearing various functional groups. The reaction is proposed to involve regioselective oxidative cyclization of the alkyne and allene to form a 4‐alkylidenecobaltacyclopentene intermediate, with subsequent C−C reductive elimination.
Copper‐Catalyzed Remote C(sp3)−H Trifluoromethylation of Carboxamides and Sulfonamides
Authors: Liu Zhonglin , Xiao Haiwen , Zhang Benxiang , Shen Haigen , Zhu Lin , Li Chaozhong 
Published: January 2019

AbstractReported herein is an unprecedented protocol for trifluoromethylation of unactivated aliphatic C(sp3)−H bonds. With Cu(OTf)2 as the catalyst, the reaction of N‐fluoro‐substituted carboxamides (or sulfonamides) with Zn(CF3)2 complexes provides the corresponding δ‐trifluoromethylated carboxamides (or sulfonamides) in satisfactory yields under mild reaction conditions. A radical mechanism involving 1,5‐hydrogen atom transfer of N‐radicals followed by CF3‐transfer from CuII−CF3 complexes to the thus formed alkyl radicals is proposed.
Artificial Mn4Ca Clusters with Exchangeable Solvent Molecules Mimicking the Oxygen‐Evolving Center in Photosynthesis
Authors: Chen Changhui , Chen Yang , Yao Ruoqing , Li Yanxi , Zhang Chunxi 
Published: January 2019

AbstractThe natural Mn4Ca cluster in photosystem II serves as a blueprint to develop artificial water‐splitting catalysts for the generation of solar fuel in artificial photosynthesis. Although significant advances have recently been achieved, it remains a great challenge to prepare robust artificial Mn4Ca clusters that precisely mimic the structure and function of the biological catalyst. Herein, we report the isolation and structural characterization of two Mn4CaO4 complexes with polar solvent molecules, acetonitrile or N,N‐dimethylformamide, which closely mimics the two water molecules on the calcium ion, as well as the oxidation states of the four manganese ions and the main geometric structure of the natural Mn4Ca cluster. These new artificial Mn4Ca complexes provide important chemical clues to understand the structure and mechanism of the biological system.
Positively Charged Nanoaggregates Based on Zwitterionic Pillar[5]arene that Combat Planktonic Bacteria and Disrupt Biofilms
Authors: Gao Lingyan , Li Mingjun , Ehrmann Svenja , Tu Zhaoxu , Haag Rainer 
Published: January 2019

AbstractBacterial biofilms are difficult to eradicate because they are less susceptible to antibiotics and more easily develop resistance. Therefore, there is an urgent need for new materials that can combat planktonic bacteria and disrupt established biofilms. To tackle this challenge, we design a multifunctional zwitterionic pillar[5]arene, which can self‐assemble into weakly positively charged nanoaggregates that exhibit antibacterial activity against Gram‐negative Escherichia coli (DH5α) and Gram‐positive Staphylococcus aureus (SH1000) bacterial strains in solution. In addition, the zwitterionic pillar[5]arene can efficiently disrupt pre‐existing Escherichia coli (DH5α) biofilms and kill the biofilm‐enclosed bacteria without rapid generation of resistance.
From Lead Iodide to a Radical Form Lead‐Iodide Superlattice: High Conductance Gain and Broader Band for Photoconductive Response
Authors: Wang Guan‐E , Xu Gang , Zhang Ning‐Ning , Yao Ming‐Shui , Wang Ming‐Sheng , Guo Guo‐Cong 
Published: January 2019

AbstractSuperlattice materials offer new opportunities to modify optical and electrical properties of recently emerging 2D materials. The insertion of tetraethylbenzidine (EtDAB) into interlamination of the established 2D PbI2 semiconductor through a mild solution method yielded the first lead iodide superlattice, EtDAB⋅4PbI2 (EtDAB=tetraethylbenzidine), with radical and non‐radical forms. The non‐radical form has a non‐ionic structure that differs from the common ionic structures for inorganic–organic hybrid lead halides. The radical form shows five orders of magnitude greater conductance and broader photoconductive response range (UV/Vis → UV/Vis‐IR), than pure PbI2 and the non‐radical form of the superlattice.
On the Remarkable Role of the Nitrogen Ligand in the Gas‐Phase Redox Reaction of the N2O/CO Couple Catalyzed by [NbN]+
Authors: Sun Xiaoyan , Zhou Shaodong , Yue Lei , Guo Cheng , Schlangen Maria , Schwarz Helmut 
Published: January 2019

AbstractThe thermal gas‐phase catalytic reduction of N2O by CO, mediated by the transition‐metal nitride cluster ion [NbN]+, has been explored by using FT‐ICR mass spectrometry and complemented by high‐level quantum chemical calculations. In contrast to the [Nb]+/[NbO]+ and [NbO]+/[Nb(O)2]+ systems, in which the oxidation of [Nb]+ and [NbO]+ with N2O is facile, but in which neither [NbO]+ nor [Nb(O)2]+ react with CO at room temperature, the [NbN]+/[ONbN]+ system at ambient temperature mediates the catalytic oxidation of CO. The origins of the distinctly different reactivities upon nitrogen ligation are addressed by quantum chemical calculations.
Sigma‐1 Receptor Expression in DRG Neurons During a Carrageenan‐Provoked Inflammation
Authors: Jerčić Leo , Kostić Sandra , Vitlov Uljević Marija , Vukušić Pušić Tanja , Vukojević Katarina , Filipović Natalija 
Published: January 2019

ABSTRACTSigma 1 receptor (σ1R) is a non‐opioid receptor that modulates pain perception and is strongly expressed in dorsal root ganglion (DRG) neurons. We studied the changes in the expression of σ1R in different sub‐populations of DRG neurons during the first 48 hr in a carrageenan‐induced inflammation rat model, with σ1R being a possible base for the development of neuropathic pain after inflammation. Twenty Sprague Dawley rats were divided into five groups (N = 4 in each group): the control (C) group was sacrificed immediately; all other animals received an intraplantar injection of 0.1 mL 2% carrageenan and were sacrificed in 6, 12, 24 or 48 hr after the injection and DRGs were collected and processed for immunohistochemistry. σ1R fluorescence intensity decreased slightly but significantly in up to 24 hr post‐carrageenan injection in all sub‐populations of DRG neurons (ib4+; ib4− medium, ib4− large and ib4− in total; P < 0.05 – P < 0.001), with the exception of the ib4− small neurons (<25 μm; P > 0.05). This decrement was followed by a subsequent increase in σ1R fluorescence intensity 48 hr after the plantar carrageenan injection (P < 0.05 – P < 0.0001). The same trend was also observed in the CGRP+ population of the DRG neurons, in the total population as well as in the CGRP+ small (<25 μm) and larger CGRP (>25 μm) sub‐populations (P < 0.05 – P < 0.001). The presented results may contribute to further understanding of role of σ1R in the development of peripheral sensitization during inflammation. They may also be valuable for the therapeutic application of σ1R antagonists, particularly in the adjustment of the antagonist's dosage in a particular time window. Anat Rec, 302:1620–1627, 2019. © 2019 American Association for Anatomy
Carbon Nanotube@N‐Doped Mesoporous Carbon Composite Material for Supercapacitor Electrodes
Authors: Fu Xinyu , Chen Aibing , Yu Yifeng , Hou Senlin , Liu Lei 
Published: January 2019

AbstractHere, carbon nanotube@N‐doped mesoporous carbon (CNT@N‐PC) composites were synthesized by using resorcinol‐formaldehyde resin as carbon source, ionic liquids (ILs) as template, and nitrogen sources and tetraethyl orthosilicate (TEOS) as assistant agent. The use of ILs‐modified CNT with nitrogen and TEOS facilitated the generation of a richer mesoporous structure. The obtained CNT@N‐PC was composed of a CNT core and mesoporous carbon particles around it. CNT@N‐PC showed a 3D network structure like “dewy cobwebs” and had a high surface area of 857 m2 g−1, uniform pore size distribution (3.0 nm), and suitable N content (4.9 at.%). When used as supercapacitor electrode, the CNT@N‐PC exhibited a high specific capacitance (244 F g−1 at 1 A g−1), good rate capability and favorable capacitance retention (92.5 % capacitive retention after 5000 cycles), demonstrating the potential for application in high‐performance supercapacitors.
B‐Doped Fe/N/C Porous Catalyst for High‐Performance Oxygen Reduction in Anion‐Exchange Membrane Fuel Cells
Authors: Zhao Ye‐Min , Liao Li‐Mei , Yu Guo‐Qiang , Wei Ping‐Jie , Liu Jin‐Gang 
Published: January 2019

AbstractThe development of high‐performance non‐precious metal catalysts for the oxygen reduction reaction (ORR) as an alternative to platinum‐based counterparts in fuel cells is highly desirable but challenging. In this study, a facile approach for preparing a porous boron‐bearing Fe/N/C catalyst by pyrolysis was reported. The obtained FeCNB‐900 with a high surface area (784 m2 g−1) favored a 4e−‐reduction pathway for ORR, with a half‐wave potential of ∼0.86 V vs. RHE and high stability in 0.1 M KOH. Furthermore, anion‐exchange membrane fuel cells (AEMFCs) with the use of the FeCNB‐900 composite as the cathode catalyst exhibited a maximal power density of 0.172 W cm−2 without back pressure, revealing its promising potential for application in fuel cells and metal‐air batteries. Results demonstrated that the additional doping of B into Fe/N/C leads to a significant increase in the specific surface area of the catalyst composite and can adjust surface polarities as well as electronic properties and provide more active sites to impart a synergistic effect for boosting catalytic ORR performance.
Mixing Time Scale Determination in Microchannels Using Reaction Calorimetry
Authors: Reichmann Felix , Vennemann Kai , Frede Timothy Aljoscha , Kockmann Norbert 
Published: January 2019

AbstractMixing time scales are derived from heat flux profiles for an instantaneous and exothermic reaction in a commercially available microreactor. A continuous reaction calorimeter, based on numerous heat flux sensors, is used to record spatially resolved heat flux profiles in steady state. Total volumetric flow rate is varied at constant flow rate ratio and the region of main reaction progress is shifted within the microreactor according to the advancement of the mixing process. Secondary flow patterns, induced by Dean mixing elements within the microchannel at higher flow rates, enhance the mixing. Results display a decrease in mixing time at increased flow rates and energy dissipation rate. Additionally, the passive micromixer is evaluated regarding its efficiency.
Three‐Dimensional Assembly of Iron Phosphide Nanosheets: Synthesis and Enhanced Catalytic Activity for Hydrogen Evolution Reaction
Authors: Wang Min , Zhao Rupeng , Li Xingyun , Zhao Xiusong , Jiang Luhua 
Published: January 2019

AbstractIron phosphides show promising but limited activity as hydrogen evolution reaction (HER) catalysts due to the low number of active sites and poor electroconductivity. Herein, iron phosphide nanosheets were synthesized and assembled to three‐dimensional structures for the first time via a physical‐vapor‐infiltration assisted hard template strategy. The 3D structured FePx nanosheet assembly exhibits excellent electrocatalytic performance for hydrogen evolution reaction over a wide pH range, outperforming most of the FePx catalysts reported to date in activity and exhibiting superior stability to the commercial Pt/C catalyst. Spectroscopic analyses and electrochemical results support that the fast electron transfer, increased active sites and expedited mass transport, due to the 3D structure of the FePx nanosheets, boost the HER performance.