bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vanadium(III) Acetylacetonate as an Efficient Soluble Catalyst for Lithium–Oxygen Batteries
Authors: Zhao Qin , Katyal Naman , Seymour Ieuan D. , Henkelman Graeme , Ma Tianyi 
Published: July 2019

AbstractHigh donor number (DN) solvents in Li—O2 batteries that dissolve superoxide intermediates in lithium peroxide (Li2O2) formation facilitate high capacities at high rates and avoid early cell death. However, their beneficial characteristics also result in an instability towards highly reactive superoxide intermediates. Furthermore, Li—O2 batteries would deliver a superior energy density, but the multiphase electrochemical reactions are difficult to achieve when operating with only solid catalysts. Herein we demonstrate that vanadium(III) acetylacetonate (V(acac)3) is an efficient soluble catalyst that can address these problems. During discharge, V(acac)3 integrates with the superoxide intermediate, accelerating O2 reduction kinetics and reducing side reactions. During charge, V(acac)3 acts as a redox mediator that permits efficient oxidation of Li2O2. The cells with V(acac)3 exhibit low overpotential, high rate performance, and considerable cycle stability.
An Enamide‐Based Domino Reaction for a Highly Stereoselective Synthesis of Tetrahydropyrans
Authors: Kramer Philipp , Grimmer Jennifer , Bolte Michael , Manolikakes Georg 
Published: July 2019

AbstractA novel method for the highly stereoselective synthesis of tetrahydropyrans is reported. This domino reaction is based on a twofold addition of enamides to aldehydes followed by a subsequent cyclization and furnishes fully substituted tetrahydropyrans in high yields. Three new σ‐bonds and five continuous stereogenic centers are formed in this one‐pot process with a remarkable degree of diastereoselectivity. In most cases, the formation of only one out of 16 possible diastereomers is observed. Two different stereoisomers can be accessed in a controlled fashion starting either from an E‐ or a Z‐configured enamide.
Reshaping of Metal Nanoparticles Under Reaction Conditions
Authors: Zhu Beien , Meng Jun , Yuan Wentao , Zhang Xun , Yang Hangsheng , Wang Yong , Gao Yi 
Published: July 2019

AbstractThe shape of metal nanoparticles (NPs) is one of the key factors determining their catalytic reactivity. Recent in situ TEM observations show that dynamic reshaping of metal NPs occurs under the reaction conditions, which becomes a major hurdle for fully understanding catalytic mechanisms at the molecular level. This Minireview provides a summary of the latest progress in characterizing and modeling the equilibrium shape of metal NPs in various reactive environments through the joint effort of state‐of‐the‐art in situ environmental transmission electron microscopy experiments and a newly developed multiscale structure reconstruction model. The quantitative agreement between the experimental observations and theoretical modeling demonstrate that the fundamental mechanism of the reshaping phenomenon is driven by anisotropically changed surface energies under gas adsorption. The predictable reshaping of metal NPs paves the way for the rational design of truly efficient nanocatalysts in real reactions.
Metallocages for Metal Anions: Highly Charged [Co@Ge9]5− and [Ru@Sn9]6− Clusters Featuring Spherically Encapsulated Co1− and Ru2− Anions
Authors: Witzel Benedikt J. L. , Klein Wilhelm , Dums Jasmin V. , Boyko Marina , Fässler Thomas F. 
Published: July 2019

AbstractEndohedral clusters count as molecular models for intermetallic compounds—a class of compounds in which bonding principles are scarcely understood. Herein we report soluble cluster anions with the highest charges on a single cluster to date. The clusters reflect the close analogy between intermetalloid clusters and corresponding coordination polyhedra in intermetallic compounds. We now establish Raman spectroscopy as a reliable probe to assign for the first time the presence of discrete, endohedrally filled clusters in intermetallic phases. The ternary precursor alloys with nominal compositions “K5Co1.2Ge9” and “K4Ru3Sn7” exhibit characteristic bonding modes originating from metal atoms in the center of polyhedral clusters, thus revealing that filled clusters are present in these alloys. We report also on the structural characterization of [Co@Ge9]5− (1a) and [Ru@Sn9]6− (2a) obtained from solutions of the respective alloys.
Construction of a sandwich‐type wound dressing with pain‐reliever and pH‐responsive antibiotic delivery system
Authors: Ozdabak‐Sert Ayse Buse , Sen Beren , Kok Fatma Nese 
Published: July 2019

ABSTRACTA multifunctional sandwich type wound dressing was designed in which two types of microspheres, one to alleviate the pain (ibuprofen) and the other to protect the wound from infections (Gentamicin or Ciprofloxacin), were embedded into bilayer chitosan sponge. pH of the wound increases from acidic (pH ~ 5) to basic (pH ~ 8) via infection, so pH‐dependent antibiotic release system was designed using gelatin B microspheres to respond to increasing pH. Ibuprofen release from chitosan microspheres, on the other hand, was pH‐independent not to intervene with pain management in changing pH conditions. Crosslinking with glutaraldehyde (GA) affected both release profile and size distribution of microspheres and 2.5% GA was chosen to obtain pH‐responsive gelatin microspheres with narrow size distribution (80% of microspheres in between 15 and 25 μm). The final system was found to be effective against both Staphylococcus aureus and Escherichia coli and changing pH seemed to affect the antimicrobial agent delivery as desired. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48252.
Thermally conductive high‐density polyethylene as novel phase‐change material: Application‐relevant long‐term stability
Authors: Weingrill H. M. , Resch‐Fauster K. , Lucyshyn T. , Zauner C. 
Published: July 2019

ABSTRACTThe long‐term stability of thermally conductive high‐density polyethylene (HDPE)‐based compounds as phase‐change material (PCM) is investigated. For this purpose, the HDPE's thermal conductivity (TC) is first enhanced via compounding two different filler types (expanded graphite and aluminum) into the polymeric matrix. Bulky specimens of these compounds are then stored in air for up to 7289 h in the melt state to investigate the compounds' long‐term stability as PCM. Their thermo‐oxidative/thermal stability and their ability to maintain the isotropic material character (homogeneous distribution of the incorporated particles) is investigated. The compounds' degradation behavior is monitored via Fourier‐transform infrared spectroscopy and the maintenance of the homogeneous filler distribution is examined via a combined differential scanning calorimetry/thermogravimetric analysis mapping of each exposed specimen. The storage capacity decreases minimally after 7289 h of exposure. Furthermore, the incorporated filler particles enhance the thermo‐oxidative stability of HDPE as PCM. Consequently, thermally conductive HDPE is a highly interesting PCM. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48269.
Human Cartilage Homogenates Influence the Crystallization of Monosodium Urate and Inflammatory Response to Monosodium Urate Crystals: A Potential Link Between Osteoarthritis and Gout
Authors: Chhana Ashika , Pool Bregina , Wei Yicheng , Choi Ally , Gao Ryan , Munro Jacob , Cornish Jillian , Dalbeth Nicola 
Published: July 2019

ObjectiveMonosodium urate (MSU) crystal deposition and gout flares frequently affect osteoarthritic joints. This study was undertaken to examine the effects of human cartilage homogenates on MSU crystallization and MSU crystal–induced inflammation.MethodsHuman cartilage homogenates were prepared from macroscopically healthy and macroscopically diseased knee joint samples. Crystallization assays were used to test the effects of cartilage homogenates or individual cartilage factors on MSU crystallization. Changes in urate solubility, crystal nucleation, crystal growth, and total crystal mass were determined. THP‐1 cell assays were used to assess cytokine release following culture with MSU crystals grown in the presence or absence of cartilage homogenates or individual proteins.ResultsAddition of either 5% or 10% healthy cartilage homogenate increased the total mass of MSU crystals formed and resulted in formation of shorter MSU crystals compared to controls without cartilage homogenate. MSU crystal bows were observed in both the presence and absence of cartilage homogenate; however, bows formed in the presence of cartilage homogenates were significantly shorter than bows formed in their absence. There were no effect differences between macroscopically healthy and macroscopically diseased cartilage homogenates in all assessments. Addition of either type II collagen or albumin also led to the formation of shorter MSU crystals. In THP‐1 cell assays, MSU crystals grown with healthy cartilage homogenate increased the release of interleukin‐8, whereas MSU crystals grown with type II collagen or albumin had no effect on inflammatory cytokine release.ConclusionIn the presence of elevated urate levels, human cartilage homogenates increase MSU crystal formation and promote the formation of smaller crystals, which have greater inflammatory potential. These processes may contribute to the predilection of osteoarthritic joints to develop gout.
A lightweight autonomous MAV for indoor search and rescue
Authors: Bi Yingcai , Lan Menglu , Li Jiaxin , Lai Shupeng , Chen Ben M. 
Published: July 2019

AbstractMicro Aerial Vehicles (MAVs) have great potentials to be applied for indoor search and rescue missions. In this paper, we propose a modular lightweight design of an autonomous MAV with integrated hardware and software. The MAV is equipped with the 2D laser scanner, camera, mission computer and flight controller, running all the computation onboard in real time. The onboard perception system includes a laser‐based SLAM module and a custom‐designed visual detection module. A dual Kalman filter design provides robust state estimation by multiple sensor fusion. Specifically, the fusion module provides robust altitude measurement in the circumstance of surface changing. In addition, indoor‐outdoor transition is explicitly handled by the fusion module. In order to efficiently navigate through obstacles and adapt to multiple tasks, a task tree‐based mission planning method is seamlessly integrated with path planning and control modules. The MAV is capable of searching and rescuing victims from unknown indoor environments effectively. It was validated by our award‐winning performance at the 2017 International Micro Air Vehicle Competition (IMAV 2017), held in Toulouse, France. The performance video is available on https://youtu.be/8H19ppS_VXM.
Combining Prospective Acquisition CorrEction (PACE) with retrospective correction to reduce motion artifacts in resting state fMRI data
Authors: Lanka Pradyumna , Deshpande Gopikrishna 
Published: July 2019

AbstractBackgroundHead movement in the scanner causes spurious signal changes in the blood‐oxygen‐level‐dependent (BOLD) signal, confounding resting state functional connectivity (RSFC) estimates obtained from functional magnetic resonance imaging (fMRI). We examined the effectiveness of Prospective Acquisition CorrEction (PACE) in reducing motion artifacts in BOLD data.MethodsUsing PACE‐corrected RS‐fMRI data obtained from 44 subjects and subdividing them into low‐ and high‐motion cohorts, we investigated voxel‐wise motion‐BOLD relationships, the distance‐dependent functional connectivity artifact and the correlation between head motion and connectivity metrics such as posterior cingulate seed‐based connectivity and network degree centrality.ResultsOur results indicate that, when PACE is used in combination with standard retrospective motion correction strategies, it provides two principal advantages over conventional echo‐planar imaging (EPI) RS‐fMRI data: (a) PACE was effective in eliminating significant negative motion‐BOLD relationships, shown to be associated with signal dropouts caused by head motion, and (b) Censoring with a lower threshold (framewise displacement >0.5 mm) and a smaller window around the motion corrupted time point provided qualitatively equivalent reductions in the motion artifact with PACE when compared to a more conservative threshold of 0.2 mm required with conventional EPI data.ConclusionsPACE when used in conjunction with retrospective motion correction methods including nuisance signal and motion parameter regression, and censoring, did prove effective in almost eliminating head motion artifacts, even with a lower censoring threshold. Use of a lower censoring threshold could provide substantial savings in data that would otherwise be lost to censoring. Three‐dimensional PACE has negligible overhead in terms of scan time, sequence modifications or additional and hence presents an attractive option for head motion correction in high‐throughput resting‐state BOLD imaging.
The role of amino acids in the amplification and quality of DNA vectors for industrial applications
Authors: Dorward Alison , O'Kennedy Ronan D. , Folarin Olusegun , Ward John M. , Keshavarz‐Moore Eli 
Published: July 2019

AbstractIn this study, we have demonstrated that the type and feeding regimen of amino acids have a significant impact on the quality as well as the quantity of DNA vectors produced. Nutrient pool and factorial design experiments were carried out in order to identify the amino acids involved in increased biomass and induction of plasmid amplification. Leucine, glycine, and histidine were responsible for increased biomass and leucine starvation in the presence of histidine was implicated in plasmid amplification. Supercoiling of the plasmid was optimized using a dual feeding strategy. As a result of this, a fed‐batch fermentation strategy for the production of a 6.9 kb plasmid, pSVß, in Escherichia coli DH5α was developed. In batch fermentation, a maximum plasmid yield of 39.4 mg/L equivalent to 11.3 mg/g dry cell weight (DCW) was achieved with casein hydrolysate limitation. About 90% of plasmid was in the supercoiled (SC) form after 31 hr of fermentation but only remained so for a short period, leading to a very brief window for harvesting cells at scale. Subsequently, a fed‐batch fermentation using a dual feeding strategy was employed. A mean maximum plasmid yield of 44 mg/L equivalent to 9.1 mg plasmid/g DCW was achieved. After 25 hr, 90% of plasmid was in the SC form and remained at this level for the remaining 10 hr of the fermentation, allowing adequate time for the harvesting of cells without the loss of supercoiling of product. This study emphasized that optimizing fermentation strategy and identifying the essential nutrients are beneficial for bioprocessing of plasmid DNA for therapeutic applications.
FPGA implementation of error control codes in VHDL: An undergraduate research project
Authors: Gilbert Jordan M. , Robbins Catherine , Sheikh Waseem 
Published: July 2019

AbstractError control codes (ECC) play an important role in the detection and correction of data errors over unreliable or noisy communication channels. The main idea of ECC is to add redundant bits to the message on the transmitter, which can be used to detect and correct certain errors on the receiver. ECC are used in numerous applications such as telecommunications, Internet, and data storage. Different types of ECC exist such as linear block, convolutional, and turbo codes. This paper presents results from an innovative undergraduate research project involving implementation of linear block, cyclic and convolutional codes in very high speed integrated circuit hardware description language (VHDL) using a field‐programmable gate array (FPGA). FPGA is a suitable platform for implementing ECC due to the advantages of performance, time to market, cost, reliability, and long‐term maintenance. As part of this project, (7,4) Hamming code used for linear block and cyclic codes and convolutional codes with constraint length k of 3 and code rate (k/n) of 1/2 were implemented in VHDL on a Xilinx Spartan‐6 FPGA using ISE 14.7. Two undergraduate students at Purdue University Northwest worked on this project. This was the students’ first exposure to ECC, VHDL, and FPGA, as undergraduate students are usually not introduced to these topics in traditional electrical and computer engineering curriculum. The goal of this project was to provide students with hands‐on experience using industry‐standard VHDL software and FPGA hardware platforms to implement ECC. This paper presents the results of this innovative project including register‐transfer level schematics, simulations, and VHDL code for encoders and decoders for the various ECC implemented, and students’ reflections on the project.
Genetic Encoding of a Bioconjugation Handle for [2+2+2] Cycloaddition Reactions
Authors: Travis Christopher R. , King Elizabeth A. , Gaunt Gillian H. , Young Douglas D. 
Published: July 2019

AbstractProtein bioconjugates have many critical applications, especially in the development of therapeutics. Consequently, the design of novel methodologies to prepare protein bioconjugates is of great importance. Herein we present the development and optimization of a novel strategy to prepare bioconjugates through a genetically encoded [2+2+2] cycloaddition reaction. To do this, a novel unnatural amino acid (UAA) containing a dipropargyl amine functionality was synthesized and incorporated site specifically. This UAA‐containing protein was reacted with an alkyne‐containing fluorophore to afford a covalently linked, well‐defined protein bioconjugate. This reaction is convenient with an optimized reaction time of just two hours at room temperature and yields a stable, polysubstituted benzene ring. Overall, this work contributes a new bioconjugation strategy to the growing toolbox of reactions to develop protein bioconjugates, which have a myriad of applications.
Poly(ionic liquid)‐Based Hybrid Hierarchical Free‐Standing Electrolytes with Enhanced Ion Transport and Fire Retardancy Towards Long‐Cycle‐Life and Safe Lithium Batteries
Authors: Huang Teng , Long Man‐Cheng , Wu Gang , Wang Yu‐Zhong , Wang Xiu‐Li 
Published: July 2019

AbstractIonic liquid electrolytes (ILEs), owing to their wide electrochemical window, high ionic conductivity, and low volatility, have been extensively applied in the field of energy storage devices. However, it is extremely significant and greatly challenging to seek the counterbalance of good mechanical properties and excellent electrochemical performances, including a high transference number of ILEs for safe flexible lithium batteries. In this work, a novel hybrid poly(ionic liquid)‐based quasi‐solid electrolyte containing silica nanoparticles (SiO2‐PIL‐QSE) is fabricated through the one‐step in situ polymerization of the ionic liquid covalently tethered to silica nanoparticles (SiO2‐IL‐TFSI), which fills a poly(vinylidene fluoride‐hexafluoropropylene) (PVdF‐HFP) porous membrane prepared through phase inversion. The hybrid hierarchical porous architecture endows the SiO2‐PIL‐QSE with excellent thermal stability, good fire safety (i. e. nonflammable and low shrinkage), improved mechanical strength, and excellent electrochemical performance, including a high room‐temperature ionic conductivity of 1.69 mS cm−1, a superior electrochemical window up to 5.5 V, as well as a high lithium‐ion transference of 0.46. Accordingly, the LiFePO4|SiO2‐PIL‐QSE|Li cell can maintain a discharge specific capacity of 133.7 mAh g−1at 0.1 C at 25 °C with a capacity retention ratio of 91.9 % after 400 cycles. The excellent performances and good applicability in the pouch‐type battery of SiO2‐PIL‐QSE indicate a good prospect in the field of flexible solid‐state polymer batteries (SSPB).
Efforts towards an On‐Target Version of the Groebke–Blackburn–Bienaymé (GBB) Reaction for Discovery of Druglike Urokinase (uPA) Inhibitors
Authors: Gladysz Rafaela , Vrijdag Johannes , Van Rompaey Dries , Lambeir Anne‐Marie , Augustyns Koen , De Winter Hans , Van der Veken Pieter 
Published: July 2019

AbstractTarget‐guided synthesis (TGS) has emerged as a promising strategy in drug discovery. Although reported examples of TGS generally involve two‐component reactions, there is a strong case for developing target‐guided versions of three‐component reactions (3CRs) because of their potential to deliver highly diversified druglike molecules. To this end, the Groebke–Blackburn–Bienaymé reaction was selected as a model 3CR. We recently reported a series of druglike urokinase inhibitors, and these serve as reference compounds in the present study. Due to the limited number of literature reports on target‐guided 3CRs, multiple experimental parameters were optimized here. Most challenging was the formation of imine intermediates under near‐physiological conditions. This aspect was addressed by exploring chemical imine stabilization strategies. Notably, imines are also crucial intermediates of other 3CRs. Such systematic studies are strongly required for further development of the TGS domain but are largely absent in the literature. Hence, this work is intended as a reference for future multicomponent‐based TGS studies.
A Hexanuclear Niobium Cluster Compound Crystallizing as Macroscopic Tubes
Authors: König Jonas , Köckerling Martin 
Published: July 2019

AbstractCompounds with ordered structures in one or two dimensions are exciting materials and investigated intensively in many different areas of science. Many activities have been put into the preparation of low‐dimensional nano‐scaled structures and many compounds in this size regime are known. Contrary, the number of known compounds that have low‐dimensional macroscopic sized structures that form directly in a chemical reaction is very limited. Here, we present the synthesis of the niobium cluster compound [(Et2O)2H]2[Nb6Cl18], crystals of which grow in form of large hexagonal empty tubes of several centimeter length and diameters in the range of 2 mm. The single‐crystal X‐ray structure of this compound has been refined. Under warming, the compound readily eliminates diethyl ether molecules and decomposes. From a closer look at the crystallization process a step‐by‐step scheme of the procedure of the tube growth is proposed. The overall conclusion from this proposal is that a crucial balance between the cluster solution concentration, the crystal growth speed and the ether diffusion speed results in the formation of macroscopic crystal tubes.