bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inflammatory immune response in rabbits with Staphylococcus aureus biofilm–associated sinusitis
Authors: Wu Xianmin , Zhang Yue , Chen Xiaoyun , Chen Jun , Jia Minghui 
Published: July 2018

BackgroundStaphylococcus aureus is the most commonly isolated bacterium from patients with surgically recalcitrant chronic rhinosinusitis (CRS). Understanding the immune responses to S aureus biofilms will provide insights into how the host response may be manipulated by therapeutic agents to improve the chances of successfully preventing and treating these infections. In this study, we investigated the inflammatory immune response in a rabbit model of S aureus biofilm–related sinusitis by analyzing the levels of some major inflammatory cytokines.MethodsEighteen New Zealand white rabbits were randomly divided into 3 groups: a blank‐control group; a negative‐control group; and a model group. Four weeks after the biofilm‐associated sinusitis models were established, the sinus mucosa was harvested and examined using hematoxylin‐eosin (H&E) staining, scanning electron microscopy (SEM), reverse transcription polymerase chain reaction (RT‐PCR), and western blotting. The expression levels of inflammatory cytokines were analyzed statistically.ResultsInterleukin (IL)‐1β, IL‐8, and tumor necrosis factor (TNF)‐α expression levels were significantly higher in the model group than in the blank‐control group (p < 0.05); mRNA levels were increased by 1600%, 230%, and 130%, respectively, and the protein levels were increased by 180%, 100%, and 100%, respectively. In contrast, IL‐4 and IL‐5 mRNA levels were reduced by 44% and 70%, respectively, compared with the blank‐control group (p < 0.05).ConclusionS aureus biofilms in the rabbit maxillary sinus mucosa were associated with increased IL‐1β, IL‐8, and TNF‐α expression, and decreased IL‐4 and IL‐5 expression.
Enantioselective Nazarov Cyclizations Catalyzed by an Axial Chiral C6F5‐Substituted Boron Lewis Acid
Authors: Süsse Lars , Vogler Maria , Mewald Marius , Kemper Benedict , Irran Elisabeth , Oestreich Martin 
Published: July 2018

AbstractA chiral variant of B(C6F5)3 with a 3,3′‐disubstituted binaphthyl backbone is shown to catalyze Nazarov cyclizations with high levels of enantio‐ and diastereocontrol. The parent B(C6F5)3 also promotes these ring closures efficiently. This electrocyclization is another example of the still small family of C−C bond formations mediated by B(C6F5)3 as the catalyst.
A Bioinspired Synthesis of Polyfunctional Indoles
Authors: Huang Zheng , Kwon Ohhyeon , Huang Haiyan , Fadli Aziz , Marat Xavier , Moreau Magali , Lumb Jean‐Philip 
Published: July 2018

AbstractPolyfunctional indoles bearing substituents at C5 and C6 are prevalent in natural products, pharmaceuticals, agrochemicals, and materials. Owing to the remoteness of the C5 and C6 positions, indoles of this family can be difficult to prepare, and often require multistep syntheses. Herein, we describe a concise process that converts simple derivatives of tyrosine into 5,6‐difunctionalized indoles by direct oxidation of C−H, N−H, and O−H bonds. Our work draws inspiration from the biosynthetic polymerization of tyrosine to make melanin pigments, but makes an important departure to provide well‐defined indole heterocycles.
Cucurbit[8]uril (CB[8])‐Based Supramolecular Switches
Authors: Pazos Elena , Novo Paula , Peinador Carlos , Kaifer Angel E. , García Marcos D. 
Published: July 2018

AbstractThe use of cucurbit[8]uril as a molecular host has emerged in the chemical literature as a reliable strategy for the creation of dynamic chemical systems, owing to its ability to form homo‐ and heteroternary complexes in aqueous media with appropriate molecular switches as guests. In this manner, CB[8]‐based supramolecular switches can be designed in a predictable and modular fashion, through the selection of appropriate guests able to condition the redox, photochemical, or pH‐triggered behavior of tailored multicomponent systems. Furthermore, CB[8] allows the implementation of dual/triple and linear/orthogonal stimuli‐dependent properties into these molecular devices by a careful selection of the guests. This versatility in their design gives these supramolecular switches great potential for the rational development of new materials, in which their function is not only determined by the custom‐made stimuli‐responsiveness, but also by the transient aggregation/disaggregation of homo‐ or heteromeric building blocks.
Iridium‐Catalyzed Reductive Alkylations of Secondary Amides
Authors: Ou Wei , Han Feng , Hu Xiu‐Ning , Chen Hang , Huang Pei‐Qiang 
Published: July 2018

AbstractReported herein is the first direct, metal‐catalyzed reductive functionalization of secondary amides to give functionalized amines and heterocycles. The method is shown to have exceptionally broad scope with respect to suitable nucleophiles, which cover both hard and soft C nucleophiles as well as a P nucleophile. The reaction exhibits good chemoselectivity and tolerates several sensitive functional groups.
Process simulation and assessment of crude oil stabilization unit
Authors: Rahmanian Nejat , Aqar Dhia Y. , Bin Dainure Muhammad F. , Mujtaba Iqbal M. 
Published: July 2018

AbstractCrude oil is an unrefined petroleum composed of wide range of hydrocarbon up to n‐C40+. However, there are also a percentage of light hydrocarbon components present in the mixture. Therefore, to avoid their flashing for safe storage and transportation, the live crude needs to be stabilized beforehand. This paper aims to find the suitable operating conditions to stabilize an incoming live crude feed to maximum true vapor pressure (TVPs) of 12 psia (82.7 kPa) at Terengganu Crude Oil Terminal, Malaysia. The simulation of the process has been conducted by using Aspen HYSYS.The obtained results illustrate that the simulation data are in good agreement with the plant data and in particular for the heavier hydrocarbons. For the lighter components, the simulation results overpredict the plant data, whereas for the heavier components, this trend is reversed. It was found that at the outlet temperature (85–90°C) of hot oil to crude heat exchanger (HX‐220X), the high‐pressure separator (V‐220 A/B) and the low‐pressure separator (V‐230 A/B) had operating pressures of (400–592 kPa) and (165–186 kPa), respectively, and the live crude was successfully stabilized to a TVP of less than 12 psia. The impact of main variables, that is, inlet feed properties, three‐phase separators operating pressure, and preheater train's performance on the product TVP, are also studied. Based on the scenarios analyzed, it can be concluded that the actual water volume (kbbl/day) has greater impact on the heat exchanger's duty; thus, incoming free water to Terengganu Crude Oil Terminal should be less than 19.5 kbbl/day (9.1 vol%) at the normal incoming crude oil flow rate of 195 (kbbl/day).
Improvement of students’ understanding about the phenomena of groundwater pumping by using computer software
Authors: Zhou Xiang‐Lian , Wang Jian‐Hua 
Published: July 2018

AbstractA teaching‐learning methodology by using computational software in teaching groundwater pumping in aquifer system is presented. In order to ensure the students grasp the theory and method of groundwater flow, as well as land subsidence due to pumping groundwater. The computational software‐COMSOL is used to solve the fully coupling equilibrium equations and flow equation. The assessment of the instructor includes: homework, group discussions, and small projects, which help to figure out the degree of understanding of students’ knowledge points. In addition, the teachers prompt students to reflect on what they have learned and use the obtained responses to evaluate the effectiveness of the course. The survey finds that most students believe that they can understand the equilibrium equations and the fully coupled flow equation according to the teacher's instructs, and can perform computer operations independently. The final test results show that this teaching‐learning methodology by using computational software has a very good teaching effect.
Game‐ready 3D hair model from a small set of images
Authors: Vanakittistien Nuttapon , Sudsang Attawith , Chentanez Nuttapong 
Published: July 2018

AbstractWe present a system for creating a hair model that matches a user's hairstyle from images. The model consists of guide hair strands and can be used in a real‐time hair simulator. Our goal differs from most previous works that aim to create realistic high‐resolution hair for off‐line applications or create a mesh of the exterior of the hair volume for image manipulation. Our primary aim is for a user to be able to put his/her hairstyle into game or other real‐time applications. By taking photos in eight views of the user's head using a smartphone camera and segmenting the images with some easy‐to‐use tools, the player will obtain his/her own hair model in NVIDIA's HairWorks, which is a hair simulator used in many games. We show a number of results demonstrating the capabilities of our system in this paper.
Asymmetric Hydrogenation of Polysubstituted Aromatic Ketones Catalyzed by the DIPSkewphos/PICA Derivative–Ruthenium(II) Complexes
Authors: Utsumi Noriyuki , Arai Noriyoshi , Kawaguchi Kei , Katayama Takeaki , Yasuda Toshihisa , Murata Kunihiko , Ohkuma Takeshi 
Published: July 2018

AbstractThe DIPSkewphos/PICA derivative‐Ru(II) complexes catalyzed asymmetric hydrogenation of significantly sterically hindered 2’,3’,4’,5’,6’‐pentamethylacetophenone, which was not reduced with NaBH4 at 25 °C, with a substrate‐to‐catalyst molar ratio (S/C) of 2000 under 50 atm of H2 in a base‐containing 2‐propanol to afford the alcohol in 99 % ee quantitatively. A series of polysubstituted aromatic ketones was smoothly reacted with an S/C of 300–10,000 under 10–50 atm of H2, yielding the alcoholic products in up to 99 % ee. The catalyst system achieved an industrial‐scale (50 kg) hydrogenation of 2’,6’‐dichloro‐3’‐fluoroacetophenone, affording the alcohol in 96 % isolated yield and in 98 % ee. The obtained alcoholic product is known as a key intermediate for the synthesis of the medicine crizotinib.
High Performance Electrocatalyst Based on MIL‐101(Cr)/Reduced Graphene Oxide Composite: Facile Synthesis and Electrochemical Detections
Authors: Gu Jianxia , Yin Xiangdang , Bo Xiangjie , Guo Liping 
Published: July 2018

AbstractIn this work, a Cr‐based MOF (MIL‐101(Cr))/reduced grapheme oxide(rGO) electrocatalyst was prepared through a one‐pot hydrothermal method. The obtained composite was characterized via scanning electron microscopy, transmission electron microscopy, X‐ray diffraction and other standard techniques. Electrochemical methods were adopted to study the electrocatalytic ability of the composite. The results imply that, compared to the single components, it exhibits higher electrocatalytic activity for the reduction of metronidazole and stripping of Cd2+ and Pb2+. Optimizing the ratio of MIL‐101(Cr) and rGO, an electrochemical sensor was prepared using MIL‐101(Cr)/rGO‐20 and used for detection of metronidazole, Cd2+ and Pb2+, respectively. The linear range for metronidazole can be divided in two parts, i. e. from 0.5 to 200 μM and from 200 to 900 μM. The limit of detection is 0.24 μM (S/N=3, n=10). Likewise, it also exhibits a wide linear range from 0.05 to 6.0 μM for the detection of Cd2+ and Pb2+. The corresponding detection limits are found to be 5.2 nM and 3.0 nM (S/N=3, n=10), respectively. The proposed sensor also possesses superb selectivity, reproducibility, stability and can be applied to detect real samples with desired recovery rates. In addition, the possible reduction mechanism of metronidazole and adsorption mechanism of Cd2+ and Pb2+ were further discussed simply in this work.
3D‐1D Heterostructure of CoZn Oxyphosphide Nanosheets Anchored on Carbon Nanotubes as Electrocatalysts for the Oxygen Evolution Reaction
Authors: Xu Hui , Zhang Ke , Liu Chaofan , Tian Lin , Du Yukou 
Published: July 2018

AbstractRealizing high‐efficiency electrochemical transformation of water is of paramount significance in the field of energy storage and conversion but still a major challenge. Herein, we successfully design and fabricate a class of 3D‐1D heterostructure of 3D CoZn oxyphosphide nanosheet assemblies anchored on 1D carbon nanotubes through a facile one‐pot method. Interestingly, owing to the doping of phosphorus atoms, modified electronic structures, as well as high surface areas, the well‐designed 3D‐1D CoZnP/CNTs nanohybrids exhibit excellent electrocatalytic performances toward oxygen evolution reaction, which needs an overpotential of only 281 mV to achieve a current density of 10 mA cm−2 and exhibits no evidences for activity degradation for 24 h, holding great potentials for acting as highly efficient electrocatalysts for the oxygen evolution reaction. This work may offer new options for constructing promising nanocatalysts with well‐defined heterostructure for water splitting and beyond.
High Ionic Conductor Member of Garnet‐Type Oxide Li6.5La3Zr1.5Ta0.5O12
Authors: Kataoka Kunimitsu , Akimoto Junji 
Published: July 2018

AbstractSingle‐crystal rods of Li6.5La3Zr1.5Ta0.5O12 were grown by floating zone melting. The typical size of the single‐crystal rod was 8 mm in diameter and 70 mm in length. Li6.5La3Zr1.5Ta0.5O12 crystallizes in a cubic structure with an Ia‐3d space group and the lattice parameter a=12.9455 (6) Å. The crystal structure of Li6.5La3Zr1.5Ta0.5O12 was refined to the conventional values of R=3.32 % and wR=4.45 % using single‐crystal X‐ray diffraction data, and to R=8.82 % and wR=7.45 % using single‐crystal neutron diffraction data. Li‐ions in the crystal structure occupied two crystallographic sites: the distorted tetrahedral 96 h site and the distorted octahedral 96 h site. Analyzing the results of AC impedance measurements, we estimated the total Li‐ion conductivity of member in Li6.5La3Zr1.5Ta0.5O12 to be 1.27×10−3 S cm−1 at 298 K. This value is the highest in the reported Li6.5La3Zr1.5Ta0.5O12 members. Using NMR spectroscopy, we determined the Li diffusion coefficient to be 1.57×10−13 m2 s−1 at 298 K and 7.96×10−13 m2 s−1 at 333 K. These values related to Li‐ion migration are higher than those reported for polycrystalline samples.
Optically Functionalized Grid‐Type Complexes by a Post‐Assembly Strategy
Authors: Eggers Berend , Ziener Ulrich 
Published: July 2018

AbstractBisterpyridine‐based grid complexes can serve as supramolecular three‐dimensional scaffolds for the construction of larger molecular assemblies. Through functionalization of the ligand with azide groups, followed by self‐assembly and metal‐free Huisgen reactions, eight pyrene molecules can be attached to the grid structure in a single reaction step. The orientation and proximity provided by the scaffold allows for tuning the fluorescence properties of the dye molecules.
Carbene‐Stabilized Exceptional Silicon Halides
Authors: Khan Shabana , Roesky Herbert W. 
Published: July 2018

AbstractThe isolation of stable carbenes, such as N‐heterocyclic carbenes, cyclic alkyl amino carbenes, and abnormal N‐heterocyclic carbenes, has encouraged synthetic chemists to use them as neutral ligands for stabilizing unusual compounds with main group elements. In this Minireview, an overview is provided of the recent developments in the chemistry of carbene‐stabilized silicon halides, in which the silicon atoms are in low oxidation state. The structural diversities emanating from the differences in the HOMO–LUMO gaps of various carbenes will also be discussed.
Listeriolysin O Binding Affects Cholesterol and Phospholipid Acyl Chain Dynamics in Fluid Cholesterol‐Rich Bilayers
Authors: Kozorog Mirijam , Sani Marc‐Antoine , Separovic Frances , Anderluh Gregor 
Published: July 2018

AbstractListeriolysin O (LLO) is a pore‐forming toxin that enables survival and cell‐to‐cell spread of foodborne bacterial pathogen Listeria monocytogenes, which is responsible for the life‐threatening disease, listeriosis. LLO–membrane interactions are crucial for pathogenicity of Listeria, but remained unexplained in detail at the molecular level. Here we addressed them by means of 2H, 31P, 13C and 19F solid‐state NMR spectroscopy. Different fluid and ordered cholesterol‐rich membrane lipid bilayer systems were prepared and checked for the integrity and properties in the presence of LLO. LLO has significantly changed dynamics of phospholipid acyl chains of more fluid cholesterol‐rich bilayers, whereas the lipid bilayer organization was not affected. LLO has also affected cholesterol dynamics by increasing the intensity of low frequency motions, indicating direct interactions of LLO with cholesterol. Additionally, the LLO protein was shown to interact differently with lipid membranes, depending on the properties of cholesterol‐rich membranes. The presented results, therefore, provide new insights into the interactions of the bacterial toxin LLO with cholesterol‐rich membrane systems.
Understanding Thermal and Photochemical Aryl–Aryl Cross‐Coupling by the AuI/AuIII Redox Couple
Authors: Bhattacharjee Rameswar , Datta Ayan 
Published: July 2018

AbstractSystematic mechanistic investigations of the gold(I)/gold(III) redox‐controlled aryl–aryl cross‐coupling reaction have been performed by using both a thermal and photochemical approach. Electron‐deficient and electron‐rich arenes were considered as the coupling partners of the reaction. Based on transition‐state modeling and distortion/interaction analyses, it is shown that AuI prefers to react with electron‐deficient arenes whereas AuIII likes to activate electron‐rich arenes. This orthogonal reactivity of gold makes it an efficient catalyst for the aryl–aryl cross‐coupling reaction. The crucial role of the carboxylate ligand in the reaction has been elucidated through analysis of the transition states. It is shown that due to the presence of two coordination sites, a carboxylate ligand can stabilize the transition state more efficiently than other monodentate ligands such as chloride (Cl−). Moreover, carbon−boron transmetalation is shown to be favorable over direct C−H metalation, hence reactions initialized by C−B transmetalation are expected to be much faster and selective. Additionally, a dual photoredox/gold catalyst was employed to access the AuI/AuIII catalytic cycle for the cross‐coupling reaction. [Ru(bpy)3]2+ was used as the photoredox catalyst for the reaction, which, on excitation, transfers an electron to one of the coupling partners, namely a diazonium salt (ArN2+), and initializes the cycle.
Mutations of Histidine 13 to Arginine and Arginine 5 to Glycine Are Responsible for Different Coordination Sites of Zinc(II) to Human and Murine Peptides
Authors: Aliès Bruno , Borghesani Valentina , Noël Sabrina , Sayen Stephanie , Guillon Emmanuel , Testemale Denis , Faller Peter , Hureau Christelle 
Published: July 2018

AbstractBecause mice and rats do not naturally develop Alzheimer's disease, genetically modified animals are required to study this pathology. This striking difference in terms of disease onset could be due to three alterations in the murine sequence (R5G, Y10F and H13R) of the amyloid‐β peptide with respect to the human counterpart. Whether the metal‐ion binding properties of the murine peptide are at the origin of such different amyloidogenicity of the two peptides is still an open question. Herein, the main zinc binding site to the murine amyloid‐β at physiological pH has been determined through the combination of several spectroscopic and analytical methods applied to a series of six peptides with one or two of the key mutations. These results have been compared with the zinc binding site encountered in the human peptide. A coordination mechanism that demonstrates the importance of the H13R and R5G mutations in the different zinc environments present in the murine and human peptides is proposed. The nature of the minor zinc species present at physiological pH is also suggested for both peptides. Finally, the biological relevance and fallouts of the differences determined in zinc binding to human versus murine amyloid‐β are also discussed.
Template‐Directed Synthesis of an Inverted Spiro Architecture
Authors: Wanner Martin J. , Steemers Luuk , Uiterweerd Michiel T. , Klijn Raquel S. , Ehlers Andreas W. , van Maarseveen Jan H. 
Published: July 2018

AbstractThe regular bicyclic spiro motif is highly abundant given its synthetic accessibility while the diastereomer—virtually obtained through inversion at the central atom—is almost unknown. We have developed methodology to access the elusive inverted spiro architecture by employing a covalent template‐directed approach. Comparison with the regular spiro bicycle analog unequivocally established the diastereomeric relationship, providing insight into the fascinating stereochemical and structural properties.
Photochemistry of OPN: Formation of Cyclic PON and Reversible Combination with Carbon Monoxide
Authors: Wu Zhuang , Song Chao , Liu Jie , Lu Bo , Lu Yan , Trabelsi Tarek , Francisco Joseph S. , Zeng Xiaoqing 
Published: July 2018

AbstractCyclic PON, a first 16‐electron triatomic ring consisting of two first‐row elements, has been generated through 193 nm laser photolysis of OPN in cryogenic matrices. When the photolysis (365 nm) was performed in the presence of CO, OPN combines CO and furnishes an exotic acyclic molecule OPNCO. Upon the 193 nm laser irradiation, OPNCO dissociates mainly to OPN and CO with traces of PN and CO2. The identification of cyclic PON and OPNCO with IR spectroscopy is supported by 15N‐labeling experiments and quantum chemical calculations.
Photocatalyzed Intermolecular Aminodifluoromethylphosphonation of Alkenes: Facile Synthesis of α,α‐Difluoro‐γ‐aminophosphonates
Authors: Yang Qiang , Li Chong , Qi Zhi‐Chao , Qiang Xiao‐Yue , Yang Shang‐Dong 
Published: July 2018

AbstractAn efficient and practical method for the synthesis of α,α‐difluoro‐γ‐aminophosphonates through photocatalyzed intermolecular aminodifluoromethylphosphonation of alkenes has been developed. In this reaction, difluoromethylphosphonate is used as an important fluorinated reagent. Furthermore, the mild reaction conditions, simple operation, and broad substrate scope make this protocol very practical and attractive. The derivatization reaction in the synthesis of difluoromethylphosphonated chiral binaphthylamine ligands and α,α‐difluoro‐γ‐aminophosphoric acid highlight the applicability of this method.
Dismantling of Vinyl Ethers by Pentanuclear [(iPr3P)Ni]5H6: Facile Cooperative C−O, C−C and C−H Activation Pathways
Authors: Shoshani Manar M. , Semeniuchenko Volodymyr , Johnson Samuel A. 
Published: July 2018

AbstractThe [(iPr3P)Ni]5H6 cluster (1) and H2C=CHOtBu react at room temperature to form the new pentanuclear NiH carbide [(iPr3P)Ni]5H4(C)(CO) (3), along with an equivalent of isobutylene. This transformation requires the activation of multiple unreactive bonds, including C−H, C−C, and C(sp3)−O bond cleavage. Analysis of the reaction mixture by 1H NMR revealed the production of two additional paramagnetic species, assigned as [(iPr3P)Ni]4H4(C‐CH3)NiOtBu (4 a) and [(iPr3P)Ni]4H4(C‐CH2OtBu)NiOtBu (5 a), which arise from C(sp2)−O bond cleavage and CH bond rearrangements. The reaction of 1 with H2C=CHOSiMe2CH2Ph produced the isolable 4 a analogue [(iPr3P)4Ni5]H4(CCH3)(OSiMe2CH2Ph) (4 c). An isolable analogue of 5 a was obtained from the reaction of 1 with H2C=CHOAd (Ad=1‐admantyl), which produced [(iPr3P)4Ni5]H4(CCH2OAd)(OAd) (5 d). The utilization of both cluster faces and vertices for bonding substrate fragments in these transformations demonstrates the remarkable flexibility of the robust Ni5H4 core in the cooperative activation of multiple C−O, C−C and C−H bonds.