bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nature Inspired Molecular Design: Stereoselective Synthesis of Bicyclic and Polycyclic Ethers for Potent HIV‐1 Protease Inhibitors
Authors: Ghosh Arun K. , Brindisi Margherita 
Published: June 2018

AbstractWe have developed a conceptually new generation of non‐peptidic HIV‐1 protease inhibitors incorporating novel structural templates inspired by nature. This has resulted in protease inhibitors with exceptional potency and excellent pharmacological and drug‐resistance profiles. The design of a stereochemically defined bis‐tetrahydrofuran (bis‐THF) scaffold followed by modifications to promote hydrogen bonding interactions with the backbone atoms of HIV‐1 protease led to darunavir, the first clinically approved drug for treatment of drug resistant HIV. Subsequent X‐ray crystal structure‐based design efforts led us to create a range of exceptionally potent inhibitors incorporating other intriguing molecular templates possessing fused ring polycyclic ethers with multiple stereocenters. These structural templates are critical to inhibitors’ exceptional potency and drug‐like properties. Herein, we will highlight the synthetic strategies that provided access to these complex scaffolds in a stereoselective and optically active form, enabling our medicinal chemistry and drug development efforts.
Metal‐Free [3+2]‐Cycloaddition of Thiiranes with Isothiocyanates, Isoselenocyanates and Carbodiimides: Synthesis of 2‐Imino‐Dithiolane/Thiaselenolane/Thiazolidines
Authors: Satheesh Vanaparthi , Kumar Sundaravel Vivek , Vijay Murugan , Barik Debashis , Punniyamurthy Tharmalingam 
Published: June 2018

AbstractMetal‐free regioselective [3+2]‐cycloaddition of 2‐aryl/alkylthiiranes with isothiocyanates, isoselenocyanates and carbodiimides is developed using BF2OTf⋅OEt2 to produce 2‐imino‐dithiolane/‐thiaselenolane/‐thiazolidine frameworks at room temperature. The selectivity, substrate scope and scale up are the important practical features.
Rhodium(II)‐Catalyzed C−H Bond Carboxylation of Heteroarenes with CO2
Authors: Huang Raolin , Li Shangda , Fu Lei , Li Gang 
Published: June 2018

AbstractA method of RhII‐catalyzed C−H carboxylation of 2‐(imidazo[1,2‐a]pyridin‐2‐yl)phenols via CO2 fixation under redox‐neutral conditions was reported, providing an access to a range of coumarin derivatives. A suitable diphosphine ligand was crucial for this reaction. This reaction could be performed under relatively lower temperature or in a shorter time than the alternative base‐promoted protocol.
Size of septectomy does not affect distribution of nasal irrigation after endoscopic modified Lothrop procedure
Authors: Roxbury Christopher R. , Tang Dennis , Shah Janki , McBride Jennifer , Woodard Troy D. , Sindwani Raj 
Published: June 2018

BackgroundThe endoscopic modified Lothrop procedure (EMLP) is commonly performed in recalcitrant frontal sinusitis, in part to achieve better penetration of medicated irrigations postoperatively. Although EMLP requires a septectomy for exposure, it is unknown whether septectomy size affects delivery of irrigations. In this study we evaluated the role of septectomy in delivery of irrigations to the EMLP cavity.MethodsEMLP was performed on fresh human cadavers with sequentially increasing septectomy (minimal septectomy: drilling across septum to combine frontal sinuses; standard septectomy: 1.5 cm anterior to middle turbinate and inferiorly to the midlevel of the turbinate; large septectomy: extension to nasal floor). Irrigation with fluorescein‐labeled water was performed with a 240‐mL irrigation bottle in the vertex position and recorded with a 30° endoscope fixed in a 4‐mm trephine in the paramedian EMLP cavity. Two blinded reviewers scored irrigation distribution recordings (0 = nasal cavity only; 1 = frontal recess; 2 = medial distribution; 3 = lateral distribution; 4 = entire sinus lavage). Distribution scores were assessed with Wilcoxon rank sum analysis.ResultsSix specimens (mean age, 75.2 ± 2.4; 50% female) were assessed. Interobserver scores were highly concordant (Kendall's W = 0.86, p < 0.01), internally validating the experiment. Distribution scores did not vary significantly when comparing minimal septectomy with standard or large septectomy (Z = 0.55, p = 0.58, Z = 0.37, p = 0.71).ConclusionIncreasing septectomy does not improve irrigation delivery in patients undergoing EMLP. These results suggest that a limited septectomy for access to the bilateral frontal sinuses is all that is required for effective drug delivery postoperatively. This strategy may reduce morbidity associated with larger septectomies.
Accessory maxillary ostium repair using middle turbinate flap: a case series of 116 patients with chronic rhinosinusitis
Authors: Penttilä Matti 
Published: June 2018

BackgroundThe ostiomeatal complex (OMC), comprising a small natural maxillary sinus ostium and narrow infundibulum, transmits the air diffusion into the antrum and mucociliary transport from the antrum, and is considered a key area in chronic rhinosinusitis (CRS). Thin membranous anterior and posterior fontanelle areas below the OMC can rupture forming a perforation, accessory maxillary ostium (AMO), that increases antral airflow changing the anatomy and function of the sinus. The purpose of this study was to report the first case series of CRS patients who had undergone repair of fontanelle defects aiming to reconstruct normal structures.MethodsBetween 2011 and 2017, a total of 157 perforations were diagnosed and repaired in 121 of 525 consecutive endoscopic sinus operations performed by the author. Defects were 3 mm to 4 mm in size (range, 1 mm to 7 mm). A flap cut from the undersurface of the middle turbinate was used. In total, 101 patients received concurrent balloon catheter dilation (BCD), while 15 patients had only an AMO repair. The mean endoscopic follow‐up time was 16 weeks (range, 1 to 188 weeks).ResultsOverall, 101 perforations were closed, 21 open, and 17 partially open. A history of earlier endoscopic sinus surgery (ESS) or BCD surgery, presence of nasal polyposis or whether the repair was made without simultaneous BCD did not influence the closure rate. Postoperative febrile sinusitis occurred in 26 patients.ConclusionRepair of AMO is in theory a beneficial and technically feasible office procedure with only transient side effects. Three out of 4 perforations were closed after repair.
Desymmetrized Leaning Pillar[6]arene
Authors: Wu Jia‐Rui , Mu Anthony U. , Li Bao , Wang Chun‐Yu , Fang Lei , Yang Ying‐Wei 
Published: June 2018

AbstractIn this work, a novel version of macrocyclic arenes, namely leaning pillar[6]arenes, was discovered and it can be considered as a tilted version of a pillar[6]arene with two hydroxy/alkoxy functionalities removed. Through a facile two‐step synthetic approaches, in conjunction with a diversity of post‐modification possibilities, a series of leaning pillar[6]arenes, with good cavity adaptability and enhanced guest‐binding capability, was synthesized, and their self‐assembly in single‐crystal states is presented. DFT calculations demonstrated that the lower rotational barrier of unsubstituted phenylene rings, the uneven electron density centered at the leaning phenyl rings, and the polarization effect along the edge generated by the hydrogen‐bond‐induced orientation of hydroxy groups greatly affected the host‐guest properties, and meanwhile provided an intuitive explanation for the pillar‐like and rigid structure of traditional pillar[6]arenes. Significantly, the crystal structure of cyclo‐oligomeric quinone was obtained by direct oxidation of leaning pillar[6]arenes.
Synthesis of carbon nanotube‐based nanocomposite and application for wastewater treatment by ultrasonicated adsorption process
Authors: Ahmadi Azqhandi M.H. , Shekari M. , Ghalami‐Choobar B. 
Published: June 2018

The sorption of methylene blue (MB) and basic yellow 28 (BY28) dyes in water on Ag@ZnO/MWCNT (Ag‐doped ZnO loaded on multiwall carbon nanotubes) nanocomposite is investigated in a batch process, optimizing starting initial dye concentration, sonication time and adsorbent mass. Isotherms and kinetic behaviours of MB and BY28 adsorption onto Ag@ZnO/MWCNT were explained by extended Freundlich and pseudo‐second‐order kinetic models. Ag@ZnO/MWCNT was synthesized and characterized using X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, field emission scanning electron microscopy and Brunauer–Emmett–Teller analysis. According to the experimental data, adaptive neuro‐fuzzy inference system (ANFIS), generalized regression neural network (GRNN), backpropagation neural network (BPNN), radial basic function neural network (RBFNN) and response surface methodology (RSM) were developed, and applied to forecast the removal performance of the sorbent. The influence of process variables (i.e. sonication time, initial dye concentration, adsorbent mass) on the removal of MB and BY28 was considered by central composite rotatable design of RSM, GRNN, ANFIS, BPNN and RBFNN. The performances of the developed ANFIS, GRNN, BPNN and RBFNN models were compared with RSM mathematical models in terms of the root mean square error, coefficient of determination, absolute average deviation and mean absolute error. The coefficients of determination calculated from the validation data for ANFIS, GRNN, BPNN, RBFNN and RSM models were 0.9999, 0.9997, 0.9883, 0.9898 and 0.9608 for MB and 0.9997, 0.9990, 0.9859, 0.9895 and 0.9593 for BY28 dye, respectively. The ANFIS model was found to be more precise compared to the other models. However, the GRNN method is much easier than the ANFIS method and needs less time for analysis. So, it has potential in chemometrics and it is feasible that the GRNN algorithm could be applied to model real systems. The monolayer adsorption capacity of MB and BY28 was 292.20 and 287.02 mg g−1, respectively.
A study on the dielectric properties of coking coal
Authors: Tao Ge , Chuanchuan Cai 
Published: June 2018

AbstractIt is of great significance for the optimization of coal microwave desulfurization technologies to know the dielectric properties of coking coal. The paper uses the dielectric constant and reflection coefficient to represent the dielectric properties of coking coal at 0.3–25 GHz of microwave frequency band, explores the coking coal's wave‐absorbing properties, and proposes the best microwave response frequency point of coking coal under civilian microwave frequency. The results show that the coking coal is a dielectric with good wave‐absorbing properties; 0.3–2.5 GHz and 16.5–25 GHz are the significant microwave response intervals for coking coal; at the frequency points of 915 and 22,125 MHz, the coking coal has stronger absorbing and transforming capacity towards the microwave.
Temperature dependency of gas barrier properties of biodegradable PP/PLA/nanoclay films: Experimental analyses with a molecular dynamics simulation approach
Authors: Salehi Abolfazl , Jafari Seyed Hassan , Khonakdar Hossein Ali , Ebadi‐Dehaghani Hassan 
Published: June 2018

ABSTRACTPolypropylene (PP)/poly(lactic acid) (PLA)/clay nanocomposite films with various compositions (PP‐rich and PLA‐rich) were prepared. Their structural and barrier properties against CO2, O2, and N2 were investigated. The microstructure of the nanocomposites was studied by scanning electron microscopy, transmission electron microscopy, and wide angle X‐ray scattering. The PP‐rich with 75/25 composition revealed the best barrier properties against all the gases which could be justified according to its microstructure. Selectivity of O2/N2 and CO2/N2 was also measured. It was found that the addition of nanoclay as a gas barrier component reduced the permeability in both systems. The permselectivity was also reduced in the PP‐rich films while it was increased in the PLA‐rich system. Moreover, the temperature dependency of permeability, selectivity, and permselectivity for PP, PLA, and PP/PLA (75/25) samples was examined. The results showed that the temperature dependence of permeability obeyed an Arrhenius equation and order of activation energy of permeability for O2, CO2, and N2 gases was found to be EP < EP/PLA < EPLA. According to solubility measurements, the order of solubility coefficient for gases was as follows: CO2 > O2 > N2. Finally, the molecular dynamics (MD) simulation was performed to estimate the diffusivity coefficients of the gases and showed that solubility increases with increasing temperature, which was in accordance with the experiments. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46665.
Combined effect of water uptake and temperature on wood polymer composites
Authors: Fortini Annalisa , Mazzanti Valentina 
Published: June 2018

ABSTRACTWood polymer composites are materials frequently used for outdoor applications, since they can operate under a large range of temperature and moisture conditions. The present work investigates the combined effect of water soaking and temperature (ranging from 10 up to 40 °C) on wood flour filled high density polyethylene. Water soaking tests have revealed that the percentage of absorbed water at the saturation plateau increases with temperature due to the induced stiffness reduction of the polymeric matrix. This hypothesis has been confirmed by scanning electron microscopy analyses, which has allowed to observe the filler–matrix interface and to measure the wood flour particle size. In addition, instrumented Charpy impact tests have shown a strong toughness reduction as a consequence of fiber–matrix debonding induced by particle swelling, which worsens with temperature. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46674.
Hysteresis Charges in the Dynamic Enrichment and Depletion of Ions in Single Conical Nanopores
Authors: Wang Dengchao , Brown Warren , Li Yan , Kvetny Maksim , Liu Juan , Wang Gangli 
Published: June 2018

AbstractInhomogeneous distribution of electrolyte ions at solid–solution interfaces at the nanometer scale is known to contribute to several emerging transport phenomena discovered from various nanopores or nanochannels. The topic has attracted extensive research effort, aiming to achieve better energy harvesting, storage, conversion, desalination and separation, sample concentration, stochastic sensing, and so on. In this report, dynamic ion concentration polarization inside charged conical nanopores, one of the two characteristics to describe the electrical double layer (EDL) structure (charge distribution and potential profile), is quantified. The hysteresis in the ion transport or redistribution in single nanopores is determined from the pinched current–potential loops by time‐dependent electrokinetic measurements. The extent of polarization in ion concentrations over different timescales, or residual charges during the transition from one ion distribution/EDL structure to another, is quantitated from the area enclosed in the hysteresis current loops. The ratio of the residual charges during the high/low conductivity states is correlated with the current ratio at the threshold potentials (rectification factor), which, in turn, serves as a convenient parameter to estimate the charge transport hysteresis. By adjusting the solution pH and ionic strength, and under different potential sweeping rates, the dynamics of ion enrichment or depletion is elucidated, respectively, and successfully described with a simple capacitive charging model. Taken together with our previous reports of the memristive ion transport in conical nanopores/nanopipettes and the physical meaning of the unique non‐zero cross‐point potential, a comprehensive view of the charge redistribution and EDL dynamics at nanoscale interfaces is offered.
A Phenylene‐Bridged Cyclohexa‐meta‐phenylene as Hexa‐peri‐hexabenzocoronene Precursor
Authors: Dumslaff Bastian , Wagner Manfred , Schollmeyer Dieter , Narita Akimitsu , Müllen Klaus 
Published: June 2018

AbstractA phenylene‐bridged cyclohexa‐meta‐phenylene was synthesized via intramolecular Yamamoto coupling of an appropriate p‐quinquephenyl derivative carrying four m‐chlorophenyl substituents. The structural proof could be obtained by single‐crystal X‐ray diffraction analysis, which also revealed a slightly strained structure with an internal phenylene bridge. Notably, this cyclo‐meta‐phenylene served as a novel precursor for hexa‐peri‐hexabenzocoronene (HBC). The cyclodehydrogenation proceeded smoothly, providing the corresponding HBC derivative as confirmed by MALDI‐TOF‐MS, and UV/Vis spectroscopy.
meso‐Functionalization of Boron(III) Subporphyrin with Boron(III) meso‐Lithiosubporphyrin
Authors: Bekki Yosuke , Shimizu Daiki , Fujimoto Keisuke , Osuka Atsuhiro 
Published: June 2018

AbstractBoron(III) meso‐lithiosubporphyrin was prepared by bromine–lithium exchange of B‐tolyl BIII meso‐bromosubporphyrin with n‐butyllithium at −98 °C. The resulting subporphyrinyllithium was treated with various electrophiles such as benzophenone, N,N‐dimethylformamide, CO2, chlorotrimethylsilane, N‐fluorobenzenesulfonimide, and dimesitylboryl fluoride to give the corresponding meso‐functionalized BIII subporphyrins. The nucleophile was also used to construct BIII subporphyrin dimers such as bis(BIII subporphyrinyl)ketone, bis(BIII subporphyrinyl)carbinol, and disilane‐bridged BIII subporphyrin dimer. The structural, optical, and electrochemical properties of these meso‐functionalized BIII subporphyrins were examined by UV/Vis absorption and fluorescence spectroscopy, electrochemical studies, and DFT calculations.
Development of Potent Pyrazolopyrimidinone‐Based WEE1 Inhibitors with Limited Single‐Agent Cytotoxicity for Cancer Therapy
Authors: Matheson Christopher J. , Casalvieri Kimberly A. , Backos Donald S. , Reigan Philip 
Published: June 2018

AbstractWEE1 kinase regulates the G2/M cell‐cycle checkpoint, a critical mechanism for DNA repair in cancer cells that can confer resistance to DNA‐damaging agents. We previously reported a series of pyrazolopyrimidinones based on AZD1775, a known WEE1 inhibitor, as an initial investigation into the structural requirements for WEE1 inhibition. Our lead inhibitor demonstrated WEE1 inhibition in the same nanomolar range as AZD1775, and potentiated the effects of cisplatin in medulloblastoma cells, but had reduced single‐agent cytotoxicity. These results prompted the development of a more comprehensive series of WEE1 inhibitors. Herein we report a series of pyrazolopyrimidinones and identify a more potent WEE1 inhibitor than AZD1775 and additional compounds that demonstrate that WEE1 inhibition can be achieved with reduced single‐agent cytotoxicity. These studies support that WEE1 inhibition can be uncoupled from the potent cytotoxic effects observed with AZD1775, and this may have important ramifications in the clinical setting where WEE1 inhibitors are used as chemosensitizers for DNA‐targeted chemotherapy.
Development of Novel Inhibitors for Histone Methyltransferase SET7/9 based on Cyproheptadine
Authors: Hirano Tomoya , Fujiwara Takashi , Niwa Hideaki , Hirano Michitake , Ohira Kasumi , Okazaki Yusuke , Sato Shin , Umehara Takashi , Maemoto Yuki , Ito Akihiro , Yoshida Minoru , Kagechika Hiroyuki 
Published: June 2018

AbstractThe histone methyltransferase SET7/9 methylates not only histone but also non‐histone proteins as substrates, and therefore, SET7/9 inhibitors are considered candidates for the treatment of diseases. Previously, our group identified cyproheptadine, used clinically as a serotonin receptor antagonist and histamine receptor (H1) antagonist, as a novel scaffold of the SET7/9 inhibitor. In this work, we focused on dibenzosuberene as a substructure of cyproheptadine and synthesized derivatives with various functional groups. Among them, the compound bearing a 2‐hydroxy group showed the most potent activity. On the other hand, a 3‐hydroxy group or another hydrophilic functional group such as acetamide decreased the activity. Structural analysis clarified a rationale for the improved potency only by tightly restricted location and type of the hydrophilic group. In addition, a SET7/9 loop, which was only partially visible in the complex with cyproheptadine, became more clearly visible in the complex with 2‐hydroxycyproheptadine. These results are expected to be helpful for further structure‐based development of SET7/9 inhibitors.
Nonstandard finite difference approach for solving 3‐compartment pharmacokinetic models
Authors: Egbelowo Oluwaseun Francis 
Published: June 2018

AbstractComplex nature of the analytical solutions to 3‐compartment pharmacokinetic models leads to the discrete approximation of the continuous differential equation been mostly used. In this paper, we applied nonstandard finite difference method to 3‐compartment pharmacokinetic models. This method was introduced to compensate for the weaknesses of methods such as the standard finite difference methods, numerical instabilities being a prime example of such. Three‐compartment pharmacokinetic model with 2 different routes of administration (IV bolus injection and IV bolus infusion) is considered for simulations. For the case when the system is homogeneous (models arising from IV bolus injection mode of administration), “exact” finite difference scheme is obtained for any step size while in the case of nonhomogeneous (models arising from IV bolus infusion route of administration), scheme that has the same qualitative behavior as the analytical solution for all step sizes is obtained. It was shown computationally that the nonstandard finite difference scheme for 3‐compartment pharmacokinetic model with IV bolus mode of administration is exact while 3‐compartment pharmacokinetic model with IV infusion is dynamically consistent with the continuous model for all step sizes.
Multi‐GPU solution to the lattice Boltzmann method: An application in multiscale digital rock simulation for shale formation
Authors: Chen Tianluo , Ning Yang , Amritkar Amit , Qin Guan 
Published: June 2018

SummaryCharacterization of rock properties is vital in producing oil and gas from shale reservoirs in an economically viable fashion. The nano‐pore structure and ultralow permeability in shale reservoirs present challenges to the traditional experimental characterization methods. Digital rock physics for the estimation of rock properties, especially for shale reservoirs, has become a powerful tool that greatly complements to lab experiments by combining advance imaging techniques with numerical simulations. The lattice Boltzmann method (LBM) is a well‐applied numerical method to simulate the fluid flow in pore structures at multiple length scales. Usually, the LBM simulation is resource intense because of its computation complexity and is facing great numerical challenges in extremely large‐cale computation. In this paper, we propose a multi‐GPU parallel implementation of 3D LBM on a hybrid high‐performance computing cluster to perform large‐scale simulations in reconstructed digital rocks. The program provides multiscale solution, pore scale and representative elementary volume (REV) scale based on the resolution of digital rock images. Optimization strategies are applied on partitioning simulation domain, improving data communication efficiency and maximizing CUDA occupancy. When running on a cluster of 32 GPUs, the proposed parallel implementation achieves a speedup of 1074x comparing to the in‐house sequential program.