bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrophobic Interaction: A Promising Driving Force for the Biomedical Applications of Nucleic Acids
Authors: Xiao Fan , Chen Zhe , Wei Zixiang , Tian Leilei 
Published: July 2020

AbstractThe comprehensive understanding and proper use of supramolecular interactions have become critical for the development of functional materials, and so is the biomedical application of nucleic acids (NAs). Relatively rare attention has been paid to hydrophobic interaction compared with hydrogen bonding and electrostatic interaction of NAs. However, hydrophobic interaction shows some unique properties, such as high tunability for application interest, minimal effect on NA functionality, and sensitivity to external stimuli. Therefore, the widespread use of hydrophobic interaction has promoted the evolution of NA‐based biomaterials in higher‐order self‐assembly, drug/gene‐delivery systems, and stimuli‐responsive systems. Herein, the recent progress of NA‐based biomaterials whose fabrications or properties are highly determined by hydrophobic interactions is summarized. 1) The hydrophobic interaction of NA itself comes from the accumulation of base‐stacking forces, by which the NAs with certain base compositions and chain lengths show properties similar to thermal‐responsive polymers. 2) In conjugation with hydrophobic molecules, NA amphiphiles show interesting self‐assembly structures with unique properties in many new biosensing and therapeutic strategies. 3) The working‐mechanisms of some NA‐based complex materials are also dependent on hydrophobic interactions. Moreover, in recent attempts, NA amphiphiles have been applied in organizing macroscopic self‐assembly of DNA origami and controlling the cell–cell interactions.
Hydration counteracts the separation of lanthanides by solvent extraction
Authors: Li Zheng , Binnemans Koen 
Published: July 2020

AbstractThe extraction of lanthanides from aqueous nitrate solutions by quaternary ammonium nitrate ionic liquids (e.g., [A336][NO3]) shows a negative sequence (i.e., light lanthanides are more efficiently extracted than heavy lanthanides), which conflicts with the lanthanide contraction. In this study, we explored the origin of the negative sequence by investigating the extraction of lanthanides from ethylammonium nitrate by [A336][NO3]. The extraction shows a positive sequence, which is converted to a negative sequence with the addition of water. The transformation from positive to negative sequences reveals that the negative sequence is caused by the hydration of lanthanide ions: hydration of lanthanide ions counteracts the extraction. Therefore, the use of solvents that have weak solvation with lanthanide ions might enhance the separation of the elements by solvent extraction.
Preparation of electrospun magnetic polyvinyl butyral/Fe2O3 nanofibrous membranes for effective removal of iron ions from groundwater
Authors: Peer Petra , Cvek Martin , Urbanek Michal , Sedlacik Michal 
Published: July 2020

AbstractRemoving iron ions from groundwater to purify, it is a challenge faced by countries across the globe, which is why developing polymeric microfiltration membranes has garnered much attention. The authors of this study set out to develop nanofibrous membranes by embedding magnetic Fe2O3 nanoparticles (MNPs) into polyvinylbutyral (PVB) nanofibers via the electrospinning process. Investigation was made into the effects of the concentration of the PVB and MNPs on the morphology of the nanofibers, their magnetic properties, and capacity for filtration to remove iron ions. The fabrication and presence of well‐incorporated MNPs in the PVB nanofibers were confirmed by scanning electron microscopy and transmission electron microscopy. Depending on the concentration of the MNPs, the membranes exhibited magnetization to the extent of 45.5 emu g−1; hence, they exceeded the performance of related nanofibrous membranes in the literature. The magnetic membranes possessed significantly higher efficiency for filtration compared to their nonmagnetic analogues, revealing their potential for groundwater treatment applications.
The Anatomical Record continues to replace wonder with knowledge through first‐hand experience of acupuncture
Authors: Albertine Kurt H. , Laitman Jeffrey T. 
Published: July 2020

AbstractA group of original papers is assembled for this thematic‐papers issue on traditional Chinese medicine (TCM). The idea for a thematic‐papers issue came from Associate Editor and Guest Editor, Jicheng Li. Jicheng's idea was to introduce concepts and studies of TCM to the editorial board of The Anatomical Record and the Journal's readership. Thus, nine papers are published that deal with biomarkers, animal models, or treatments of TCM syndromes. Uniquely, Jicheng's effort culminated in acupuncture treatment of the editorial board members by a licensed physician of TCM. We learned, first‐hand by Dr. Weixue Wang, about this ancient and vibrant holistic philosophy and medical practice. Our pleasure is to share the topic and our experience with you.
Decacyclene Radical Anions Showing Strong Low‐energy Intramolecular Absorption and Magnetic Coupling of Spins in a Hexagonal Network
Authors: Konarev Dmitri V. , Kuzmin Aleksey V. , Khasanov Salavat S. , Shestakov Alexander F. , Otsuka Akihiro , Yamochi Hideki , Kitagawa Hiroshi , Lyubovskaya Rimma N. 
Published: July 2020

AbstractTwo salts of the aromatic hydrocarbon decacyclene, {cryptand[2.2.2](Cs+)} (decacyclene.−) (1) and {Bu3MeP+}(decacyclene.−) (2), were obtained. In both salts, decacyclene.− radical anions formed channels occupied by cations. However, corrugated hexagonal decacyclene.− layers could be outlined in the crystal structure of 1 with several side‐by‐side C⋅⋅⋅C approaches. The decacyclene.− radical anions showed strong distortion in both salts, deviating from the C3 symmetry owing to the repulsion of closely arranged hydrogen atoms and the Jahn‐Teller effect. Radical anions showed intense unusually low energy absorption in the IR‐range, with maxima at 4800 and 6000 cm−1. According to the carculations, these bands can originate from the SOMO‐LUMO+1 and SOMO‐LUMO+2 transitions, respectively. Radical anions exhibited a S=1/2 spin state, with an effective magnetic moment of 1.72 μB at 300 K. The decacyclene.− spin antiferromagnetically coupled with a Weiss temperature of −11 K. Spin ordering was not observed down to 1.9 K owing to spin frustration in the hexagonal decacyclene.− layers.
Supramolecular Tubule from Seesaw Shaped Amphiphile and Its Hierarchical Evolution into Sheet
Authors: Sun Haonan , Dong Longlong , Kim Yongju , Lee Myongsoo 
Published: July 2020

AbstractAlthough supramolecular one‐dimensional (1D) and two‐dimensional (2D) structures with various unique properties have been extensively studied, the reversible switching between tubules and sheets via lateral association remains challenging. Here, we report the unique structures of a supramolecular tubular bamboo culm in which the hollow‐tubular interior is separated, at intervals, by nodes per 1.3 nm. Interestingly, the discrete tubules are able to hierarchically assemble into a flat sheet in response to an aromatic guest. The addition of trans‐azobenzene, as a guest, enables the tubules to form a hierarchical sheet assembly via the lateral interaction. The hierarchical sheet structures are disassembled into their constituent tubules upon UV irradiation due to trans‐cis isomerization. The recovery from cis‐azobenzene to trans‐form induces repeatedly the hierarchical sheet assembly, indicative of a reversible switching behavior between tubules and sheets triggered by an external stimulus.
Guidelines for practical navigation systems based on wide‐field‐integration of optic flow
Authors: Kobayashi Naoto , Bando Mai , Hokamoto Shinji , Kubo Daisuke 
Published: July 2020

AbstractThis paper shows some guidelines to improve the estimation accuracy of a navigation system, which is based on wide‐field‐integration (WFI) of optic flow. Optic flow is a vector field of relative velocities obtained by photoreceptors in image sensors, and WFI of optic flow enables motion estimation robust by integrating wide range of optic flow. Since the system has several attractive features (small size, light weight, and low computation), it is applicable to an autonomous control system of micro air vehicles. However, due to some restrictions of real systems, WFI of optic flow theory should be applied while considering sensor arrangement for better estimation. In this paper, first an adequate number and adequate optical‐axes of image sensors are investigated. Then, a new estimation system combining a gyro sensor with WFI of optic flow is discussed by numerical simulations. Finally, the essential effect for the number of cameras are verified in experiments.
An exercise program throughout pregnancy: Barakat model
Authors: Barakat Ruben 
Published: July 2020

AbstractThe physiologic processes of pregnancy and childbirth can determine the future well‐being of mothers and children due to the great quantity and quality of modifications that these processes require in all areas of the female body and fetus. Recent evidence has confirmed that modern unhealthy lifestyles negatively affect pregnancy outcomes. Engaging in unhealthy habits during pregnancy increases the risk of chronic disease in both the mother and the fetus. Regarding physical exercise during pregnancy, throughout history, many professionals and scientists have reported the best gestational conditions for the mother, fetus, and newborn. The perspectives and advice have changed over time, including periods of strong conservatism. This history has affected the recommendations for the type and amount of exercise that a healthy woman should perform during pregnancy. The aim of this article is to determine the basic aspects that physical exercise programs during pregnancy should define in the near future. Additionally, from the results of this article, we propose an exercise program model that includes many exercises spanning throughout pregnancy (3 blocks = until 20 weeks, until 30 weeks and until the end of the pregnancy). An exercise session model divided into seven parts and recommendations of operative position to exercise during pregnancy are also provided.
A rapid UHPLC–MS/MS method for the quantification of ARQ531 in rat plasma: Validation and its application to a pharmacokinetic study
Authors: Liu Jizhen , Ji Musi , Li Zhidong , Xu Xun , Li Lili , Li Huawen , Tian Yuguang , Su Xiaohua 
Published: July 2020

AbstractA simple and sensitive ultra‐high performance liquid chromatography–tandem mass spectrometric (UHPLC–MS/MS) method was developed and validated for the determination of ARQ531, a Bruton’s tyrosine kinase inhibitor in rat plasma. After protein precipitation with acetonitrile, the samples were separated on a UPLC BEH C18 column with 0.1% formic acid in water and acetonitrile as mobile phase at a flow rate of 0.4 ml/min. The mass detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring with precursor‐to‐product ion transitions of m/z 479.1 > 365.1 and m/z 441.2 > 138.1 for ARQ531 and internal standard, respectively. Good linearity (correlation coefficient > 0.9988) was achieved over the concentration range of 0.5–1,000 ng/ml and the lower limit of quantitation was 0.5 ng/ml. The accuracy ranged from −13.50 to 11.35% and the precision was <8.87%. The extraction recovery was >85.56%. ARQ531 was demonstrated to be stable under the tested conditions. The validated method was further applied to a pharmacokinetic study of ARQ531 in rats after intravenous (1 mg/kg) and oral (1, 3 and 10 mg/kg) administration. The results demonstrated that ARQ531 displayed linear pharmacokinetic profiles over the oral dose range of 1–10 mg/kg and good oral bioavailability (>50%).
Simultaneous determination of colchicine and febuxostat in rat plasma: Application in a rat pharmacokinetic study
Authors: Gabani Bhavesh Babulal , Saini Neeraj Kumar , Jairam Ravi Kumar , Shrinivas Pavan , Trivedi Ravi Kumar , Srinivas Nuggehally R. , Mullangi Ramesh 
Published: July 2020

AbstractA selective, sensitive and rapid LC–MS/MS method has been developed and validated as per US Food and Drug Administration regulatory guidelines for the simultaneous quantitation of colchicine and febuxostat in rat plasma. Colchicine and febuxostat were extracted from the rat plasma using 10% tert‐butyl methyl ether in ethyl acetate using colchicine‐d6 as an internal standard (IS). The chromatographic separation of colchicine, febuxostat and the IS was achieved using a mobile phase comprising 5 mm ammonium formate and 0.025% formic acid in acetonitrile (20:80, v/v) in isocratic mode on an Eclipse XDB‐C18 column. The injection volume and flow rate were 5.0 μl and 0.9 ml/min, respectively. Colchicine and febuxostat were detected by positive electrospray ionization in multiple reaction monitoring mode using transition pairs (Q1 → Q3) of m/z 400.10 → 358.10 and 317.05 → 261.00, respectively. The assay was linear in the ranges of 0.25–254 and 2.60–622 ng/ml for colchicine and febuxostat, respectively. The inter‐ and intra‐day precision values were 0.58–13.0 and 1.03–4.88% for colchicine and febuxostat, respectively. No matrix or carryover effects were observed during the validation. Both analytes were stable on the bench‐top, in the autosampler and in storage (freeze–thaw cycles and long‐term storage at −80°C). A pharmacokinetic study in rats was performed to show the applicability of the validated method.
An Overview of Ag‐catalyzed Synthesis of Six‐membered Heterocycles
Authors: Neetha Mohan , Aneeja Thaipparambil , Afsina C. M. A. , Anilkumar Gopinathan 
Published: July 2020

AbstractHeterocyclic chemistry is an immensely expanding field in organic synthesis owing to its potency in various disciplines like natural products chemistry, pharmaceuticals, drug discovery and industry. Silver catalysis has gained much attraction in recent years mainly in the scenario of heterocyclic synthesis. Among heterocycles, the six membered heterocycles are the most popular and widely applied in various fields. This review discusses on the investigations on various silver‐catalyzed synthesis of six‐membered heterocycles and covers literatures up to 2020.
A New Catalytic System with Balanced Activity and Durability toward Oxygen Reduction
Authors: Cao Zhenming , Xie Minghao , Cheng Haoyan , Chen Ruhui , Lyu Zhiheng , Xie Zhaoxiong , Xia Younan 
Published: July 2020

AbstractWe report a new catalytic system by partially covering the uniform Pt nanocrystals on a carbon support with an ultrathin film derived from polyacrylonitrile (PAN). The use of Pt nanocrystals uniform in both size and shape effectively suppresses Ostwald repining, while partially covering them with a PAN‐derived film prevents migration, aggregation, and detachment from the support. In addition, the pyridinic N atoms on the edges of the thermally‐treated PAN film can also weaken the O=O bond, accelerating the reduction of oxygen. Upon optimization, the new catalyst exhibits a mass activity of 0.51 mA ⋅ μg−1Pt toward oxygen reduction, substantially enhanced relative to the same catalyst without PAN (0.22 mA ⋅ μg−1Pt) and a commercial Pt/C (0.41 mA ⋅ μg−1Pt). The mass activity is essentially retained after 10,000 cycles of accelerated durability test between 0.6 V and 1.1 V in oxygen‐saturated HClO4. Even after aging in H3PO4 at 220 °C for one week, the electrochemical surface area of the catalyst is still maintained. This catalytic system holds great promise for use in various types of fuel cells with a long lifetime.
Lignin Biodegradation by a Cytochrome P450 Enzyme: A Computational Study into Syringol Activation by GcoA
Authors: Ali Hafiz Saqib , Henchman Richard H. , de Visser Sam P. 
Published: July 2020

AbstractA recently characterized cytochrome P450 isozyme GcoA activates lignin components through a selective O‐demethylation or alternatively an acetal formation reaction. These are important reactions in biotechnology and, because lignin is readily available; it being the main component in plant cell walls. In this work we present a density functional theory study on a large active site model of GcoA to investigate syringol activation by an iron(IV)‐oxo heme cation radical oxidant (Compound I) leading to hemiacetal and acetal products. Several substrate‐binding positions were tested and full energy landscapes calculated. The study shows that substrate positioning determines the product distributions. Thus, with the phenol group pointing away from the heme, an O‐demethylation is predicted, whereas an initial hydrogen‐atom abstraction of the weak phenolic O‐H group would trigger a pathway leading to ring‐closure to form acetal products. Predictions on how to engineer P450 GcoA to get more selective product distributions are given.
Polymer‐Assisted Electrophoretic Synthesis of N‐Doped Graphene‐Polypyrrole Demonstrating Oxygen Reduction with Excellent Methanol Crossover Impact and Durability
Authors: Mohmad Ghulam , Sarkar Subhajit , Biswas Ashmita , Roy Kingshuk , Dey Ramendra Sundar 
Published: July 2020

AbstractThe design and synthesis of metal‐free catalysts with superior electrocatalytic activity, high durability, low cost, and under mild conditions is extremely desirable but remains challenging. To address this problem, a polymer‐assisted electrochemical exfoliation technique of graphite in the presence of an aqueous acidic medium is reported. This simple, cost‐effective, and mass‐scale production approach could open the possibility for the synthesis of high‐quality nitrogen‐doped graphene–polypyrrole (NG‐PPy). The NG‐PPy catalyst displays an improved half wave potential (E1/2=0.77 V) in alkaline medium compared with G‐PPy (E1/2=0.66 V). Most importantly, this catalyst demonstrates excellent stability with high methanol tolerance, and it outperforms the commercial Pt/C catalyst and other previously reported metal‐free catalysts. The content of graphitic nitrogen atoms is the key factor for the enhancement of electrocatalytic activity towards oxygen reduction reactions (ORR). Interestingly, the NG‐PPy catalyst can be used as a cathode material in a zinc–air battery, which demonstrates a higher peak power density (59 mW cm−2) than G‐PPy (36.6 mW cm−2), highlighting the importance of the low‐cost material synthesis approach towards the development of metal‐free efficient ORR catalysts for fuel cell and metal–air battery applications. Remarkably, the polymer‐assisted electrophoretic exfoliation of graphite with a high yield (≈88 wt %) of few‐layer graphene flakes could pave the way towards the mass production of high‐quality graphene for a variety of applications.
First‐Generation Bispidine Chelators for 213BiIII Radiopharmaceutical Applications
Authors: Bruchertseifer Frank , Comba Peter , Martin Bodo , Morgenstern Alfred , Notni Johannes , Starke Miriam , Wadepohl Hubert 
Published: July 2020

AbstractHepta‐ and octadentate bispidines (3,7‐diazabicyclo[3.3.1]nonane, diaza‐adamantane) with acetate, methyl‐pyridine, and methyl‐picolinate pendant groups at the amine donors of the bispidine platform have been prepared and used to investigate BiIII coordination chemistry. Crystal structure and solution spectroscopic data (NMR spectroscopy and mass spectrometry) confirm that the rigid and relatively large bispidine cavity with an axially distorted geometry is well suited for BiIII and in all cases forms nine‐coordinate complexes; this is supported by an established hole size and shape analysis. It follows that nonadentate bispidines probably will be more suited as bifunctional chelators for 213BiIII‐based radiopharmaceuticals. However, two isomeric picolinate‐/acetate‐based heptadentate ligands already show very efficient complexation kinetics with 213BiIII at ambient temperature and kinetic stability that is comparable with the standard ligands used in this field. The experimentally determined hydrophilicities (log D7.4 values) show that the BiIII complexes reported are relatively hydrophilic and well suited for medicinal applications. We also present a very efficient and relatively accurate method to compute charge distributions and hydrophilicities, and this will help to further optimize the systems reported here.
Chiral, Thermally Irreversible and Quasi‐Stealth Photochromic Dopant to Control Selective Reflection Wavelength of Cholesteric Liquid Crystal
Authors: Kurosaki Yoshihisa , Sagisaka Toshiya , Matsushima Tomoo , Ubukata Takashi , Yokoyama Yasushi 
Published: July 2020

AbstractThe front cover artwork is provided by the group of Prof. Emeritus Yasushi Yokoyama and Prof. Takashi Ubukata. The image shows the generation of a colored image, whose origin is the UV‐controlled selective reflection of visible light from a cholesteric liquid crystal containing chiral photochromic molecules. Read the full text of the Article at 10.1002/cphc.202000309.
Porphycene Protonation: A Fast and Reversible Reaction Enabling Optical Transduction for Acid Sensing
Authors: Bossi Alberto , Waluk Jacek , Yivlialin Rossella , Penconi Marta , Campione Marcello , Bussetti Gianlorenzo 
Published: July 2020

AbstractNano‐sensor materials, especially if they target biological purposes, require fine control and tuning of the properties at the molecular scale when intramolecular properties have to be exploited, for example, in optical sensors. By means of optical spectroscopies (namely, spectrophotometry, spectrofluorimetry, and surface differential reflectivity), we demonstrate that thin films of porphycene show a spectacular chromatic change when exposed to acid vapors (specifically to hydrochloric acid). After exposure, the original optical properties of the porphycene films are recovered within a few seconds and without any thermal annealing. In addition, since clear spectroscopic signatures are observed both in absorption and in reflectivity, the parent porphycene is shown to be suitable even for deposition of films onto opaque substrates. These findings are of significant interest in view of potential engineering of the molecules and implementation in devices.
Seismic fracture evaluation of diaphragm joints in welded beam‐to‐box column moment connections
Authors: Tsai Ching‐Yi , Tsai Keh‐Chyuan , Li Chao‐Hsien , Wu Chung‐Che , Lin Ker‐Chun , Jhuang Sheng‐Jhih 
Published: July 2020

SummarySteel box columns are widely used in steel building structures in Taiwan due to their dual strong axes. To transfer the beam‐end moment to the column, diaphragm plates of the same thickness and elevations as the beam flanges are usually welded inside the box column. The electro‐slag welding (ESW) process is widely used to connect the diaphragms to the column flanges in Taiwan because of its convenience and efficiency. However, ESW may increase the hardness of the welds and heat‐affected zones (HAZs), while reducing the Charpy‐V notch strength in the HAZ. This situation can cause premature fracture of the diaphragm‐to‐column flange welds before a large plastic rotation is developed in the beam‐to‐box column joints. To quantify the critical eccentricity and the effectiveness of fracture prediction, this study uses fracture prediction models and finite element model (FEM) analysis to correlate the test results. In this study, two beam‐to‐box column connection subassembly tests are conducted with different loading protocols and ESW chamber shapes. To implement a fracture prediction model, the material parameters are established from circumferential notched tensile tests and FEM analysis. Test results indicate that the fracture instances can be predicted on the basis of the cumulative plastic deformation in the HAZs. Analytical results indicate that fracture instances and locations are sensitive to the relative locations of the ESW joints and beam flange. Tests also confirm that the possible fracture of the diaphragm‐to‐column flange joints can be mitigated by enlarging the chamber of the ESW joint.