bluuebunny/crossref_metadata_2025 huggingface dataset:
CRISPR-Cas Systems: A Review of their Role as Non-Canonical Antimicrobials to Combat Drug Resistance
Authors: Adesanya Oluwafolajimi Adetoye , Oniyide Segun Abayomi
Published: June 2020

Background: Since their discovery in 1928, antibiotics have revolutionized modern human medicine. A direct consequence of their widespread use and abuse is the concomitant development of sophisticated resistance mechanisms by microbes to most of these antibiotic agents. With a sharp fall in the number of new antibiotic agents under development, due to a decline in sectoral investment by the major pharmaceutical firms, now more than ever, there is an urgent need for alternative antimicrobial agents, to overcome the global health crisis of antimicrobial resistance. One such alternative are the CRISPR-Cas systems. In this review, we discuss the discovery and evolution of the CRSIPR-Cas system, their classification, their application as antimicrobial agents and the current limitations to their use.

Main Body: Since their discovery in 1987, the CRISPR-Cas systems have evolved to possess several applications in biomedical science, including their use in gene editing, genome engineering and for treating genetic diseases. One potential application that has received less attention however is their use as sequence-specific antimicrobials. The three steps in their mechanism of action – spacer acquisition, biogenesis and interference, have been demonstrated to be effective for the highly-specific elimination of targeted bacterial strains from a mixed population of bacteria in a microbial community, as well as for driving a positive selection pressure for the development of antibiotic-sensitive bacterial strains, even to the point of reversing antimicrobial resistance through the elimination of the resistance genes. However, the use of CRISPR-based antimicrobials is fraught with several challenges, ranging from concerns about delivery platforms (phage-based vs. conjugative plasmids), their application on complex microbial communities, safety considerations, to the possibility of resistance and the many regulatory hurdles against their widespread use.

Conclusion: While their efficacy has been confirmed, more studies are required to further establish CRISPR-Cas based antimicrobials in conventional medical practice.
Induction of Variability in Three Nigerian Pepper Varieties using Gamma Irradiation
Authors: Abu N. E. , Ojua E. O. , Udensi O. U.
Published: June 2020

This study was aimed at inducing mutation on three cultivars of Capsicum annuum L. to source for new and favourable genetic variations that could be exploited for better agronomic traits. The mutation was induced by exposing the seeds of Shombo, Tatase and Nsukka yellow pepper to varied dosages (0, 50, 100, 150 and 200 Gy from 60Co source) of gamma irradiation. The study was conducted in the Botanic Garden of the University of Nigeria. Seeds exposed to 50Gy produced significantly (P < 0.05) the highest number of fruits per plant, highest fruit yield and improved morphological traits in Shombo. Higher dosages of irradiation gave lower fruits per plant and yields than untreated seeds in Shombo. Tatase irradiated with 150 Gy had significantly the highest single fresh fruit weight. Generally in Tatase 50, 100 and 150Gy increased some morphological traits significantly (P < 0.05). Although 50 Gy gave highest number of fruits per plant, 100, 150 and 200Gy had significantly higher fruit yield with yield increasing as dosage increased. For Nsukka yellow, irradiation did not show a consistent pattern in improving morphological traits. But 200Gy produced significantly the highest number of fruits per plant and highest yield. Gamma irradiation dosage of 50 – 200 Gy can be exploited to create variability for improvement of morphological and yield traits in pepper plants.
Experimental and Analytical Investigations of Innovative Composite Materials Using GFRP and Iron Slag for Railway Sleepers
Authors: Shanour Ali S. , Khalil Ahmed Abdelmoamen , Riad Hany Sobhy , Bakry Heba Mahmoud
Published: June 2020

This paper presents further results of experimental testing and analytical investigation on the mechanical properties of fiber composite sleeper in order to evaluate its strength and behavior. Recycled high density polyethylene, iron slag, calcium carbonate, styrene and polyester resin were used with different percentages for manufacturing the proposed composite sleepers. Adding glass fiber ropes and woven laminates as a reinforcement to enhance the flexural capacity of the proposed composite material. Negative bending at center and positive rail seat compression were performed on full scale sleeper. Two full scale sleepers were proof loaded up to 72, 82 KN under negative bending test without any generated cracks. Also, under positive rail seat compression test, first crack occurred at load ranged from 170, 195 KN and failure load happened at load 270, 250 KN. That's mean that the strength of sleeper ranged from 36.39 to 39.30 MPa. This result showed  that  the  proposed  composite  material  of  sleeper  has  sufficient  strength  to  hold mechanical connections. Nonlinear finite element analysis (NLFEA) predicted the behavior up to failure load of the proposed composite sleeper reasonably well. This confirms that the behavior and failure modes of composite sleeper can be well predicted by simplified analysis procedures. Comparison of proposed composite with commercially available composite and timber sleepers' behavior was presented. It is found that proposed composite sleeper performance is near or similar to that of timber and better than that of commercially available composite sleepers. It is concluded that the proposed composite sleeper can be effectively used for timber sleeper replacement.
Anti-inflammatory Potentials of Fibraurea tinctoria Leaves Extract in Experimental Rats or Animals
Authors: Al-Saikhan Fahad I.
Published: June 2020

The activity of the hydroalcoholic extract of Fibraurea tinctoria leaves and anti-inflammatory was investigated. We utilized rats for which oedema was induced by carrageenan.  The extract of Fibraurea tinctoria leaves was administered orally at doses of 100, 200 and 400 mg/kg. Paw oedema was significantly minimized using all prepared doses of the extract administered. The 400 mg/kg dose producing the highest oedema reduction. The Percent Inhibition with hydroalcoholic extract of Fibraurea tinctoria and Indomethacin were 67.6% and 68.49% respectively. We concluded that this study has established the anti-inflammatory activity of hydroalcoholic extract of Fibraurea tinctoria leaves. I believe the results justify the traditional uses of the plant in the treatment of wounds and inflammation.
FGFR1 clustering with engineered tetravalent antibody improves the efficiency and modifies the mechanism of receptor internalization
Authors: Pozniak Marta , Sokolowska‐Wedzina Aleksandra , Jastrzebski Kamil , Szymczyk Jakub , Porebska Natalia , Krzyscik Mateusz Adam , Zakrzewska Malgorzata , Miaczynska Marta , Otlewski Jacek , Opalinski Lukasz
Published: June 2020

Fibroblast growth factor receptor 1 (FGFR1) transmits signals through the plasma membrane regulating essential cellular processes like division, motility, metabolism, and death. Overexpression of FGFR1 is observed in numerous tumors and thus constitutes an attractive molecular target for selective cancer treatment. Targeted anti‐cancer therapies aim for the precise delivery of drugs into cancer cells, sparing the healthy ones and thus limiting unwanted side effects. One of the key steps in targeted drug delivery is receptor‐mediated endocytosis. Here, we show that the efficiency and the mechanism of FGFR1 internalization are governed by the spatial distribution of the receptor in the plasma membrane. Using engineered antibodies of different valency, we demonstrate that dimerization of FGFR1 with bivalent antibody triggers clathrin‐mediated endocytosis (CME) of the receptor. Clustering of FGFR1 into larger oligomers with tetravalent antibody stimulates fast and highly efficient uptake of the receptor that occurs via two distinct mechanisms: CME and dynamin‐dependent clathrin‐independent endocytic routes. Furthermore, we show that all endocytic pathways engaged in FGFR1 internalization do not require receptor activation. Our data provide novel insights into the mechanisms of intracellular trafficking of FGFR1 and constitute guidelines for development of highly internalizing antibody‐based drug carriers for targeted therapy of FGFR1‐overproducing cancers.
TXNIP induces growth arrest and enhances ABT263‐induced apoptosis in mixed‐lineage leukemia‐rearranged acute myeloid leukemia cells
Authors: Noura Mina , Matsuo Hidemasa , Koyama Asami , Adachi Souichi , Masutani Hiroshi
Published: June 2020

Thioredoxin‐interacting protein (TXNIP) has been widely recognized as a tumor suppressor in various cancers, including liver, breast, and thyroid cancers. Although TXNIP is epigenetically silenced in acute myeloid leukemia (AML) cells, as in many cancer cells, its role in leukemogenesis remains elusive. Mixed‐lineage leukemia (MLL) gene rearrangements in AML are associated with poor prognosis, and the development of a new treatment method is eagerly anticipated. In this study, we first reveal that lower expression of TXNIP is correlated with shortened overall survival periods in AML patients. Moreover, we demonstrated that TXNIP overexpression significantly suppresses proliferation in AML cells harboring MLL fusion genes. TXNIP promotes autophagy by increasing expression of the autophagy protein, Beclin 1, and lipidation of LC3B. We also show that TXNIP overexpression combined with ABT263, a potent inhibitor of Bcl‐2 and Bcl‐xL, is highly effective at inducing cell death in MLL‐rearranged (MLL‐r) AML cells. In summary, this study provides insights into the molecular mechanism of TXNIP‐mediated tumor suppression and furthermore underscores the potential of TXNIP as a promising therapeutic target for MLL‐r AML.
Bryozoa,
Cristatella Mucedo
: External Morphology
Authors: Schwaha Thomas F.
Published: June 2020

This contribution describes the external morphology of the freshwater bryozoans
Cristatella mucedo
.
Bryozoa,
Cristatella Mucedo
: Musculature
Authors: Schwaha Thomas F.
Published: June 2020

This contribution describes the musculature of the freshwater bryozoans
Cristatella mucedo
.
Bryozoa,
Cristatella Mucedo
: Skeletal/Support System
Authors: Schwaha Thomas F.
Published: June 2020

This contribution describes the skeletal system of the freshwater bryozoans
Cristatella mucedo
.
Bryozoa,
Cristatella Mucedo
: Intestinal System
Authors: Schwaha Thomas F.
Published: June 2020

This contribution describes the intestinal system of the freshwater bryozoans
Cristatella mucedo
.
Eukoenenia spelaea
, Palpigradi: Musculature
Authors: Franz‐Guess Sandra , Starck J. Matthias
Published: June 2020

Palpigradi have an extensive axial muscular system in the prosoma, but relatively few muscles in the opisthosoma. The movements of the legs are partially by antagonistic muscles, but hemolymph pressure may also play an important role in moving legs, because in some leg articles antagonists are missing. From a comparative point of view, palpigrades show a most ancestral set of muscles, surprisingly being even more plesiomorphic than the chelicerate body plan.
Eukoenenia spelaea
, Palpigradi: Skeletal/Support System
Authors: Franz‐Guess Sandra , Starck J. Matthias
Published: June 2020

The endosternite is the internal skeletal/support system of Palpigradi. The endosternite is cellular with a layer of extracellular granular matrix surrounding the endosternal cells which is similar to cartilage. This granular matrix is the point of attachment for a large number of muscles.
Eukoenenia spelaea
, Palpigradi: Body Cavities
Authors: Franz‐Guess Sandra , Starck J. Matthias
Published: June 2020

Like all other arthropods, Palpigradi possess a mixocoelic body cavity, i.e. only rudiments of coelomic cavities might be present in the pericard and the nephridial sacculus. In
Eukoenenia
a pericardium is missing.
Comparison on radiation effective dose and image quality of right coronary artery on prospective ECG‐gated method between 320 row CT and 2nd generation (128‐slice) dual source CT
Authors: Li Ren‐Feng , Hou Chang‐Long , Zhou Huang , Dai Yan‐Shan , Jin Li‐Qin , Xi Qian , Zhang Jian‐Hua
Published: June 2020

This retrospective study was to compare the image quality of right coronary artery (RCA) and effective radiation dose on prospective ECG‐gated method between 320 row computed tomography (CT) and 2nd generation (128‐slice) dual source CT. A total of 215 candidates underwent CT coronary angiography using prospective ECG‐gated method, 120 patients enrolled in 320 row CT group, and 95 patients in dual source CT group. We divided RCA image quality scores as 1/2/3/4, which means excellent/good/adequate/not assessable and heart rates were considered, as well as the radiation dose. There is no statistically significant difference of RCA image quality of Score 1/2 between 320 row CT and 2nd generation dual source CT, but lower heart rate (<70/min) improved RCA image quality. Meanwhile, the 2nd generation dual source CT scan have significant lower radiation dose. For patients with high level heart rate variation, both prospective ECG‐gated method of 320 row CT scan (Toshiba) and 2nd generation dual source CT scan (Siemens) basically provided good image quality on RCA. There is an advantage of effective radiation dose reduction in prospective ECG‐gated method using the 2nd generation dual source CT scan. After the iodine contrast agent was injected into elbow vein, the threshold triggering method was used to carry out prospective gated scanning, and the acquired fault image was reconstructed by the standard post‐processing software of each manufacturer. The radiation dose value is obtained through the dose report automatically generated after each scan.
Recapitulating Pancreatic Tumor Microenvironment through Synergistic Use of Patient Organoids and Organ‐on‐a‐Chip Vasculature
Authors: Lai Benjamin Fook Lun , Lu Rick Xing Ze , Hu Yangshuo , Davenport Huyer Locke , Dou Wenkun , Wang Erika Yan , Radulovich Nikolina , Tsao Ming Sound , Sun Yu , Radisic Milica
Published: June 2020

Tumor progression relies on the interaction between neoplastic epithelial cells and their surrounding stromal partners. This cell cross‐talk affects stromal development, and ultimately the heterogeneity impacts drug efficacy. To mimic this evolving paradigm, 3D vascularized pancreatic adenocarcinoma tissue is microengineered in a tri‐culture system composed of patient‐derived pancreatic organoids, human fibroblasts, and endothelial cells on a perfusable platform, situated in a 96‐well plate. Through synergistic engineering, the benefits of cellular fidelity of patient tumor organoids are combined with the flow control of an organ‐on‐a‐chip platform. Validation of this platform includes demonstrating the growth of pancreatic tumor organoids by monitoring the change in metabolic activity of the tissue. Investigation of the tumor microenvironment highlights the role of fibroblasts in symbiosis with patient organoids, resulting in a six‐fold increase of collagen deposition and corresponding increase in tissue stiffness in comparison to fibroblast free controls. The value of a perfusable vascular network is evident in drug screening, as perfusing gemcitabine into stiffened matrix does not show the dose‐dependent effects on decrease in tumor viability as those under static conditions. These findings demonstrate the importance of a dynamic synergistic relationship between patient cells with stromal fibroblasts, in a 3D perfused vascular network, to accurately recapitulate a dynamic tumor microenvironment.
Low‐Defect Thiol‐Michael Addition Hydrogels as Matrigel Substitutes for Epithelial Organoid Derivation
Authors: Rezakhani Saba , Gjorevski Nikolce , Lutolf Matthias P.
Published: June 2020

Due to their selective crosslinking chemistry and well‐defined mechano‐biochemical characteristics, hydrogels crosslinked by thiol‐Michael addition reactions have garnered immense interest for 3D cell culture applications. These hydrogels are typically formed via end‐linking of bis‐cysteine oligopeptides and branched f‐functional (f ≥ 3) poly(ethylene glycol) (PEG). Unfortunately, this gel design accumulates excessive structural defects at a solid content below ≈10% (w/v) due to diluted bifunctional components reacting intramolecularly to form primary loops that compromise the gels' mechanical integrity and lead to excessive swelling. These limitations restrict the suitability of the gels for challenging cell culture applications, such as the growth of organoids. Here, low‐defect thiol‐Michael addition (LDTM) hydrogels based on novel building blocks designed toward minimizing structural defects are reported. Compared to the conventional gels, LDTM gels can be generated at an at least 2‐fold lower solid content, while still incorporating high concentrations of bioactive ligands (≈3 × 10‐3 m). LDTM gels promote the efficient development of fully patterned mouse intestinal organoids as well as human intestinal organoids, the latter in the absence of any animal‐derived components. Powerful alternatives are thus provided to the gold‐standard Matrigel, which is expensive and too variable for robust organoid development, facilitating translational applications of organoids.
Ferroelectric Exchange Bias Affects Interfacial Electronic States
Authors: Tuvia Gal , Frenkel Yiftach , Rout Prasanna K. , Silber Itai , Kalisky Beena , Dagan Yoram
Published: June 2020

In polar oxide interfaces phenomena such as superconductivity, magnetism, 1D conductivity, and quantum Hall states can emerge at the polar discontinuity. Combining controllable ferroelectricity at such interfaces can affect the superconducting properties and sheds light on the mutual effects between the polar oxide and the ferroelectric oxide. Here, the interface between the polar oxide LaAlO3 and the ferroelectric Ca‐doped SrTiO3 is studied by means of electrical transport combined with local imaging of the current flow with the use of scanning a superconducting quantum interference device (SQUID). Anomalous behavior of the interface resistivity is observed at low temperatures. The scanning SQUID maps of the current flow suggest that this behavior originates from an intrinsic bias induced by the polar LaAlO3 layer. Such intrinsic bias combined with ferroelectricity can constrain the possible structural domain tiling near the interface. The use of this intrinsic bias is recommended as a method of controlling and tuning the initial state of ferroelectric materials by the design of the polar structure. The hysteretic dependence of the normal and the superconducting state properties on gate voltage can be utilized in multifaceted controllable memory devices.
Evolution of 3D Printing Methods and Materials for Electrochemical Energy Storage
Authors: Egorov Vladimir , Gulzar Umair , Zhang Yan , Breen Siobhán , O'Dwyer Colm
Published: June 2020

Additive manufacturing has revolutionized the building of materials, and 3D‐printing has become a useful tool for complex electrode assembly for batteries and supercapacitors. The field initially grew from extrusion‐based methods and quickly evolved to photopolymerization printing, while supercapacitor technologies less sensitive to solvents more often involved material jetting processes. The need to develop higher‐resolution multimaterial printers is borne out in the performance data of recent 3D printed electrochemical energy storage devices. Underpinning every part of a 3D‐printable battery are the printing method and the feed material. These influence material purity, printing fidelity, accuracy, complexity, and the ability to form conductive, ceramic, or solvent‐stable materials. The future of 3D‐printable batteries and electrochemical energy storage devices is reliant on materials and printing methods that are co‐operatively informed by device design. Herein, the material and method requirements in 3D‐printable batteries and supercapacitors are addressed and requirements for the future of the field are outlined by linking existing performance limitations to requirements for printable energy‐storage materials, casings, and direct printing of electrodes and electrolytes. A guide to materials and printing method choice best suited for alternative‐form‐factor energy‐storage devices to be designed and integrated into the devices they power is thus provided.
Luminescent Quantum Dots from Nonluminescent 2D Pyrediyne for Bioimaging Applications
Authors: Arya Jyothibabu Sajila , Prabakaran Palani , Kannan Ramya , Prasad Edamana , Sankararaman Sethuraman
Published: June 2020

Pyrediyne is one of the recent entries to carbon‐based 2D material series with better electronic and charge transport properties compared to graphdiyne. Herein, the preparation of pyrediyne‐based quantum dots (PDYQDs), with tunable emission, from nonluminescent 2D precursor pyrediyne is investigated. As‐prepared PDYQDs are characterized by various microscopic as well as spectroscopic techniques such as high‐resolution transmission electron microscopy, atomic force microscopy, X‐ray diffraction, Fourier‐transform infrared spectroscopy, matrix‐assisted laser desorption/ionization, UV‐visible, and fluorescence spectroscopy. The simple preparatory method and absence of heavy metal or external passivating agents make this pyrene‐containing QDs unique. Moreover, the tunable emission (410–548 nm), notable photoluminescence quantum yield (23%), and negligible cytotoxicity of PDYQDs are explored for bioimaging in MCF7 breast cancer cells. The findings in the present study are encouraging to explore novel carbon‐based QDs from their 2D counterparts to enhance their applications in various biological and optoelectronic devices.
Smart Superhydrophobic Films with Self‐Sensing and Anti‐Icing Properties Based on Silica Nanoparticles and Graphene
Authors: Chu Zhenming , Jiao Weicheng , Huang Yifan , Yan Meiling , Zheng Yongting , Wang Rongguo , He Xiaodong
Published: June 2020

As one of the major passive anti‐icing method, superhydrophobic surfaces have attracted extensive attentions to solve the icing problem. Self‐sensing properties of multifunctional superhydrophobic materials broaden the application prospects such as anti‐icing detection. Here, 1H,1H,2H,2H‐perfluorodecyltrichlorosilane (FDTS) modified graphene based micronano hierarchical structure films are prepared, which exhibit superior superhydrophobic characteristics with the water contact angle (WCA) of 152.1° and sliding angle (SA) of 2.3° under the temperature of −10 °C and condensation. The dynamic impact and bounce process of supercooled droplets on micronano hierarchical structure film indicates excellent anti‐icing performance. More importantly, the prepared superhydrophobic film can rapidly sense the impacting droplets of different falling heights and sizes, and record the entire process of water droplets freezing. This research is of great significance for the research of real‐time anti‐icing and low‐temperature self‐sensing.
Strengthening of Titanium by Equal Channel Angular Pressing ‐ Impact on Oxide Layer Properties of Pure Titanium and Ti6Al4V
Authors: Franz Melanie , Mingler Bernhard , Krystian Maciej , Sajti Laszlo , Pohl Darius , Rellinghaus Bernd , Wolf‐Brandstetter Cornelia , Scharnweber Dieter
Published: June 2020

Equal channel angular pressing (ECAP) as a method applicable to large samples for strengthening metallic materials via severe plastic deformation has recently attracted considerable interest. For biomedical applications, ECAP‐treated pure titanium is a promising alternative for implants subjected to high mechanical loads as it contains no potentially cytotoxic alloying elements. The consequences of an ECAP treatment for the physico‐chemical properties of the air formed passive layers of pure or alloyed titanium, which are of the utmost importance for the biological response to these materials, are studied here for the first time. This includes mechanical, electron microscopic, and electrochemical investigations in protein containing media to study the reactions that occur immediately after implantation in the phase boundary between implant and biological system. The ECAP treatment results in a positive shift of the flatband potential and a particularly strong increase of the donor density for the native oxide layers. This is associated with increased electronic conductivity of the oxide layers under anodic polarization.
Electrically Tunable Printed Bifocal Liquid Crystal Microlens Arrays
Authors: Kamal Waqas , Lin Jia‐De , Elston Steve J. , Ali Taimoor , Castrejón‐Pita Alfonso A. , Morris Stephen M.
Published: June 2020

In this communication, the fabrication of electrically tunable bifocal liquid crystal (LC) microlenses using drop‐on‐demand inkjet printing is demonstrated. By treating the glass substrate with a homeotropic alignment layer, the printed droplets are found to form plano‐convex lenses with focal lengths in the range of 220–463 µm, depending upon the number of droplets deposited at each location on the substrate. The precision of the process allows for the microlenses to be deposited in between in‐plane indium tin oxide electrodes. In the presence of a high amplitude electric field, the director within the LC droplets is observed to align with the direction of the applied field, but without any accompanying distortion in the droplet profile. However, these changes in the LC director alignment are found to result in a bifocal behavior rather than a continuous change in the focal length. It is also found that there exists a range of voltages for which two focal planes are observed.
Fabrication of Orderly Porous Anodic Alumina Optical Waveguide Sensor via Interface Hydrophilic Treatment for the Detection of Small and Large Molecules
Authors: Wang Guiqiang , Wang Chunnan , Shao Ruomei , Sun Shuqing
Published: June 2020

In this paper, an orderly porous anodic alumina (PAA) optical waveguide sensor is presented with a simple and low‐cost fabrication method. Both the gold film and PAA film undergo interface hydrophilic treatment. The refractive index (RI) sensitivity and resolution for the first order of transverse magnetic (TM1) mode reached 64.67 deg RIU−1 and 1.73 × 10−6 RIU, respectively. Small and large molecules are used to verify its sensing feasibility. For the detection of small molecule, the glucose molecule is used and its limit of detection (LOD) of 39.03 mg L−1, that is 0.22 × 10−3 m, is achieved. In addition, bovine serum albumin (BSA) is used as a model of large molecule to adsorb onto the surface of PAA film due to the characteristic of BSA molecule. The results show that the adsorption of BSA onto the PAA surface belongs to 1:1 model of Langmuir adsorption and the LOD reached 2.67 × 10−12 m based on the threefold standard deviation theory and Langmuir fitting. Further, in the experiment of fluorescence enhancement, the LOD as low as 770.72 × 10−15 m for BSA/Cy5 is obtained, owing to the high adsorption capacity of PAA nanostructure and field enhancement of the PAA waveguide.
Safety Assessment of Microneedle Technology for Transdermal Drug Delivery: A Review
Authors: Zhu Dan Dan , Zhang Xiao Peng , Zhang Bao Li , Hao Yu Ying , Guo Xin Dong
Published: June 2020

The promising development of the microneedle (MN) drug delivery system has prompted its clinical application as a substitute for traditional hypodermic injection needles. In addition to the satisfactory MN technology design for various application prospects, safety issues during MN use are increasingly an important consideration. This review aims to gather data from published literature regarding safety evaluations on MNs in relation to pain, skin irritation, in vivo degradation, as well as storage stability. By analyzing the existing testing methods and the safety performance of MNs, the description of MN safety is updated as painless, minimally invasive, and stable during storage. However, the development of MNs that can degrade in a human body should be addressed to accelerate clinical applications.
Structural Basis of Human Helicase DDX21 in RNA Binding, Unwinding, and Antiviral Signal Activation
Authors: Chen Zijun , Li Zhengyang , Hu Xiaojian , Xie Feiyan , Kuang Siyun , Zhan Bowen , Gao Wenqing , Chen Xiangjun , Gao Siqi , Li Yang , Wang Yongming , Qian Feng , Ding Chen , Gan Jianhua , Ji Chaoneng , Xu Xue‐Wei , Zhou Zheng , Huang Jinqing , He Housheng Hansen , Li Jixi
Published: June 2020

RNA helicase DDX21 plays vital roles in ribosomal RNA biogenesis, transcription, and the regulation of host innate immunity during virus infection. How DDX21 recognizes and unwinds RNA and how DDX21 interacts with virus remain poorly understood. Here, crystal structures of human DDX21 determined in three distinct states are reported, including the apo‐state, the AMPPNP plus single‐stranded RNA (ssRNA) bound pre‐hydrolysis state, and the ADP‐bound post‐hydrolysis state, revealing an open to closed conformational change upon RNA binding and unwinding. The core of the RNA unwinding machinery of DDX21 includes one wedge helix, one sensor motif V and the DEVD box, which links the binding pockets of ATP and ssRNA. The mutant D339H/E340G dramatically increases RNA binding activity. Moreover, Hill coefficient analysis reveals that DDX21 unwinds double‐stranded RNA (dsRNA) in a cooperative manner. Besides, the nonstructural (NS1) protein of influenza A inhibits the ATPase and unwinding activity of DDX21 via small RNAs, which cooperatively assemble with DDX21 and NS1. The structures illustrate the dynamic process of ATP hydrolysis and RNA unwinding for RNA helicases, and the RNA modulated interaction between NS1 and DDX21 generates a fresh perspective toward the virus–host interface. It would benefit in developing therapeutics to combat the influenza virus infection.
Ultrawide Temperature Range with Stable Permittivity and Low Dielectric Loss in (1 − x)[0.90Na0.5Bi0.5TiO3‐0.10BiAlO3]‐xNaNbO3 System
Authors: Ren Pengrong , Wang Jiale , He Jiaojiao , Wang Yike , Yuan Hai , Hao Yun , Frömling Till , Wan Yuhui , Shi Yonggui , Zhao Gaoyang
Published: June 2020

High‐temperature capacitors have become an important research topic recently as commercially available capacitors cannot fulfill the new requirements from industry. In this work, a new ceramic ternary system (1 − x)[0.9Na0.5Bi0.5TiO3‐0.1BiAlO3]‐xNaNbO3 is introduced, and the effects of NaNbO3 concentration on macroscopic phase structure, locally disordered structure, dielectric properties, conduction properties, and energy storage properties are studied. At the optimum composition of x = 0.30, an ultrawide temperature range (−90 and 320 °C) covering both stable permittivity (Δε′/ε′25°C ≤ ± 15%) and low dielectric loss (tan δ ≤ 0.02) can be obtained. Additionally, this material has a high RC constant of 2.8 s and a high energy storage efficiency of 88% under the electric field of 60 kV cm−1 at room temperature. Therefore, this work provides a very promising candidate for dielectrics used in multilayer ceramic capacitors (MLCC) in an ultrawide operating temperature range.
Graphdiyne Ink for Ionic Liquid Gated Printed Transistor
Authors: Zhang Mingjia , Li Yuan , Li Xiaodong , Wang Naiyin , Huang Changshui
Published: June 2020

Graphdiyne‐based electronic devices have recently attracted a lot of research interest due to their excellent performance and promising application prospects in carbon electronics. Here, graphdiyne (GDY) inks are prepared by solution processing of newly grown GDY material, which is suitable for fabricating fully printed thin‐film field‐effect transistor (FET). An ionic liquid gate dielectric is used as a gate to maintain stable on/off ratios at different VSD compared to conventional SiO2 dielectric. Significantly, the GDY network combined with ionic liquid allows a general and cheap approach to achieve printed FET devices containing 2D carbon materials. Furthermore, a flexible FET on polyethylene terephthalate is developed, which still reaches a repeatable on/off ratio of more than 102. These results enable the design of wearable or large‐area carbon‐based electronics involving graphdiyne semiconductors, suggesting a promising new carbon material for novel electronic devices.
Mapping of Heterogeneous Catalyst Degradation in Polymer Electrolyte Fuel Cells
Authors: Cheng Lei , Khedekar Kaustubh , Rezaei Talarposhti Morteza , Perego Andrea , Metzger Michael , Kuppan Saravanan , Stewart Sarah , Atanassov Plamen , Tamura Nobumichi , Craig Nathan , Zenyuk Iryna V. , Johnston Christina M.
Published: June 2020

Pt catalysts in polymer electrolyte fuel cells degrade heterogeneously as the catalyst particles are exposed to local variations throughout the catalyst layer during operation. State‐of‐the‐art analytical techniques for studying degradation of Pt catalysts do not possess fine spatial resolution to elucidate such non‐uniform degradation behavior at a large electrode level. A new methodology is developed to spatially resolve and quantify the heterogeneous Pt catalyst degradation over a large area (several cm2) of aged MEAs based on synchrotron X‐ray microdiffraction. PEFC single cells are aged using voltage cycling as an accelerated stress test and the degradation heterogeneity at a micrometer length scale is visualized by mapping Pt catalyst particle size after voltage cycling. It is demonstrated in detail that the Pt catalyst particle size growth is non‐uniform and follows the flow field geometry. The Pt particle size growth is greater in the area under the flow field land, while it is minimal in the area under the flow field channel. Additional non‐uniformity is observed with the Pt particle size increasing more rapidly at the air outlet area than the Pt particle size at the inlet area.
Ruxolitinib combined with etanercept induce a rapid response to corticosteroid‐refractory severe acute graft vs host disease after allogeneic stem cell transplantation: Results of a multi‐center prospective study
Authors: Zhao Yanmin , Wu Hengwei , Shi Jimin , Luo Yi , Li Xiaoqing , Lan Jianping , Ni Wanmao , Lu Ying , Chen Lieguang , Tan Yamin , Lai Xiaoyu , Yu Jian , Huang He
Published: June 2020

About half of patients with severe acute graft vs host disease (aGVHD) show resistance to treatment with first‐line steroids. We enrolled 64 patients with grades III‐IV SR‐aGVHD after allogeneic hematopoietic stem cell transplantation (allo‐SCT), to assess the efficacy and safety of the combination therapy of ruxolitinib and etanercept. The overall response rate was 87.5% (95% CI, 79.7%‐95.3%) at day 28 of the combination treatment, from which 73.4% reached complete response (CR). A marked reduction ≥75% in daily corticosteroid dosing was documented in 75.4% of patients at day 28. Delayed time from aGVHD to ruxolitinib (OR = 4.88, 95% CI, 0.98‐23.56), stages 3‐4 liver aGVHD (OR = 8.57, 95% CI, 0.96‐46.59) and gut Enterobacteriaceae colonization (OR = 12.39, 95% CI, 1.71‐59.77) were related to incomplete response. Grades 3/4 anemia, leukopenia, or thrombocytopenia and CMV‐reactivation were found in 29.7%, 26.6%, 39.1%, and 50.0% of patients, respectively. So, 25 (39.1%) experienced complications of severe infection ≥3 grade, in which pulmonary infections were most frequent (15/64, 23.4%). The 2‐year overall survival (OS) after the combination therapy was 61.2%. The 2‐year incidence of non‐relapse mortality and relapse of the underlying malignancy was 26.7% and 15.7%, respectively. Combined treatment with ruxolitinib and etanercept was very effective and relatively safe for severe aGVHD patients, while the various infection complications deserve more attention. This study was registered at the Chinese Clinical Trial Registry (ChiCTR1900024408).
Environmental maintenance with effective and useful zoning to protect patients and medical staff from COVID‐19 infection
Authors: Ogawa Fumihiro , Kato Hideaki , Sakai Kazuya , Nakamura Kana , Ogawa Mizuki , Uchiyama Munehito , Nakajima Kento , Ohyama Yutaro , Abe Takeru , Takeuchi Ichiro
Published: June 2020

Aim

The coronavirus disease 2019 (COVID‐19) pandemic has accelerated all over the world, and global health‐care systems have become overwhelmed with potentially infectious patients seeking testing and care. It is essential to set up effective and useful zoning to prevent the spread of infection to and from medical staff or other patients with effective use of standard precautions with personal protective equipment (PPE).

Methods

We repurposed a general ward into an acute care unit for severe COVID‐19 patients taking into consideration airflow, the direction of movement of medical staff, and prevention of the spread of infection to medical staff and other patients. We checked the daily condition and body temperature of all medical staff for 60 days.

Results

There was no evidence of COVID‐19 infection in any medical staff or other patients during the period thanks to effective and useful zoning with PPE.

Conclusion

Special wards and rooms should be set up for future protection of medical staff and other patients, and prevent the explosion of COVID‐19 infection with effective and useful zoning with PPE.
Quantifying beryllium concentrations in plant shoots from forest ecosystems using cation‐exchange chromatography and quadrupole ICP‐MS
Authors: Uhlig David , Goldberg Tatiana , Frick Daniel A. , von Blanckenburg Friedhelm
Published: June 2020

Beryllium (Be) is known to be one of the most toxic elements but at the same time exerts a stimulating effect on plant growth. Despite this contradiction, little is known about the Be metabolism in living organisms, partially because of the low amounts present and because the analysis of Be in plants by ICP‐MS remains challenging. The challenges arise from the complex organic matrix, the low abundance of Be relative to the other plant essential elements, and the matrix effects resulting thereof in the plasma. To address these challenges, we developed and evaluated a new method for Be concentration analysis in plant material. Key is the quantitative separation of Be from the other matrix elements by cation‐exchange chromatography. The new method was verified by processing seven reference materials representing different plant matrices yielding a long‐term reproducibility of 16% (RSD). Applying the method, Be concentrations in tree, shrub, bush, and grass samples grown in non‐polluted ecosystems from four temperate forests and a tropical rainforest were measured. The Be concentrations in different plant organs range from 0.01 to 63 ng/g that suggest a natural baseline for Be concentrations of 52 ng/g (95 percentile of non‐woody tissue) that may serve as bioindicator for Be pollution in the environment. Comparison of Be concentrations in plants with the soil's biologically available fraction revealed that Be is discriminated from uptake into shoots and thus can be considered as non‐essential.
Ni(II) and Cu(II) complexes of bidentate thiosemicarbazone ligand: Synthesis, structural, theoretical, biological studies and molecular modeling
Authors: Jain Pallavi , Sharma Swati , Kumar Neeraj , Misra Namita
Published: June 2020

The conventional condensation and refluxing process was employed to synthesize Ni(II) and Cu(II) complexes of Methylcarbamatethiosemicarbazone ligand. Reactions were carried out at the pH of 7. The molar ratio of the ligand and metal salt was 2:1. The structures of the synthesized metal complexes were suggested by different analytical techniques such as magnetic susceptibility, molar conductance, IR, EPR and UV spectroscopy. Experimental studies confirmed the octahedral geometry for all the complexes. The geometry of the ligand and complexes were also confirmed by theoretical studies. The complexes were investigated for biological action against pathogenic fungi (C. krusei, C. albican) and bacteria (S. aureus, E. coli). The antimicrobial results confirmed superior inhibition potential of the metal complexes as compared with the parent ligand. The enhanced antimicrobial activities might be due to the chelation. Molecular‐docking assays confirmed the strong interaction of ligand with target antimicrobial protein DNA gyrase‐B.
Preparation and characterization of Cu supported on 2‐(1H‐benzo[d]imidazol‐2‐yl)aniline‐functionalized Fe3O4 nanoparticles as a novel magnetic catalyst for Ullmann and Suzuki cross‐coupling reactions
Authors: Danqing Liang , Ming Jin , Li Li , Mohammadnia Majid
Published: June 2020

Copper supported on 2‐(1H‐benzo[d]imidazol‐2‐yl)aniline (BIA)‐functionalized Fe3O4 nanoparticles (Cu‐BIA‐Si‐Fe3O4) as a novel magnetic catalyst was designed and used for the synthesis of new products via Ullmann and Suzuki cross‐coupling reactions. The Ullmann reaction was performed by mixing arylboronic acid with aniline derivatives in dimethylsulfoxide solvent. Also, diaryls were synthesized via Suzuki C–C reactions between aryl halides and phenylboronic acid in the same solvent. The prepared materials and catalyst were characterized with various analytical techniques. The Cu‐BIA‐Si‐Fe3O4 catalyst demonstrated catalytic efficiency with good to excellent yields for both types of reactions in comparison with commercial palladium catalysts. Also, the catalyst could be recovered by a simple filtration and retained its activity even after several cycles.
1D Azido bridged Cu(II) coordination polymer with 1,3‐oxazolidine ligand as an effective catalyst for green click synthesis of 1,2,3‐triazoles
Authors: Bikas Rahman , Ajormal Fatemeh , Noshiranzadeh Nader , Emami Marzieh , Kozakiewicz Anna
Published: June 2020

A new 1D azido bridged Cu(II) coordination polymer with 1,3‐oxazolidine based ligand, [Cu(H3L)(μ1,3‐N3)(N3)]n (1), was synthesized and characterized by elemental analysis and spectroscopic methods. The structure of 1 was also determined by single crystal X‐ray analysis which indicated the 1D polymeric chain is generated by end‐to‐end (EE) azide bridge. The obtained compound was employed as catalyst in green click synthesis of β‐hydroxy‐1,2,3‐triazoles from one‐pot three‐component cycloaddition reaction of epoxide‐azide‐alkyne. The catalytic reactions were carried out in water as a safe, cheap and green solvent. The catalytic studies indicated that the obtained 1D azido bridged Cu(II) coordination polymer is an active catalyst for preparing β‐hydroxy‐1,2,3‐triazoles. The effect of temperature on the selectivity of the catalytic system was studied and the results indicated this catalytic system has high selectivity at low temperatures. The structure the product obtained from the reaction of 2,3‐epoxypropylphenylether, azide and 1‐ethynyl‐1‐cyclohexanol (T4) was determined by single crystal X‐ray analysis. The results indicate Cu(II) coordination polymers can be a new class of catalytic systems for green click synthesis of 1,2,3‐triazoles.
Study on mass at the bottom of the pipe and gas velocity distribution during flow blockage collapsing under pipe‐rotation mechanism
Authors: Jia Wenguang , Feng Shaohua
Published: June 2020

The flow blockage of the horizontal pipe is a severe problem in dense pneumatic conveying; accelerating the collapse of blockage can improve the efficiency of powder transportation. In this paper, the pipe‐rotation mechanism was proposed for the first time, and its effect on blockage collapse was preliminarily discussed. A horizontal pipe‐rotation geometry with a linear variation of rotating speed was established, and the rotational speed was 0, 150, 300, 450, and 600 rpm, respectively. The collapsing process of a single slug passing through the rotating horizontal pipe was simulated by using the Computational fluid dynamics (CFD)‐discrete element method (DEM) model. The change of mass at the bottom of the pipe and gas velocity distribution was studied. It was found that, in the prophase of flow, centrifugal force is more dominant than circumferential friction; in the anaphase of flow, the opposite is true. In terms of gas velocity distribution and pressure distribution, pipe rotation with different speeds has the same action law to flow blockage collapse. Moreover, 300 rpm was found to be the optimal speed in our study, instead of the faster ones. It is trusted that the method reported in this paper will serve as a helping source for the upcoming studies towards the slug collapse of dense‐phase pneumatic conveying.
Separation of phenolic compounds from oil mixtures by betaine‐based deep eutectic solvents
Authors: Li Guangsheng , Xie Qiang , Liu Qian , Liu Jinchang , Wan Chaoran , Liang Dingcheng , Zhang Haiyong
Published: June 2020

Separation of phenolic compounds from coal tar is of both economic and technological interest in the processing of coal tar. In this work, three deep eutectic solvents (DES) of betaine‐glycerol, betaine‐dl‐lactic acid, and betaine‐levulinic acid were formed and used to extract phenolic compounds from model coal tar. The effects of extraction time, temperature, initial phenol content, and mass ratio of DES to phenol on extraction were investigated. Then, the extraction and formation mechanisms of extractant were studied by the experimental and simulation methods. In addition, the neutral oil entrainment and the recycling of DES were also investigated. The results showed that phenol could be efficiently extracted in short time by three DES and the temperature had little effect on phenol extraction. Fourier transform infrared spectroscopy and deformation charge density indicated that the three DES are formed with hydrogen bonding interaction, the hydrogen bond acceptor and hydrogen bond donor of DES can form hydrogen bonding with phenol, respectively, and then synergistic extract phenol from model oil. The betaine‐glycerol (Bet‐Gly) was determined to be the preferable solvent with the extraction efficiency of 94.6% and 5.2% neutral oil entrainment under optimal conditions. It is an advantageous extractant in the separation of phenolic compounds from coal tar.
Connectivity, habitat, and flow regime influence fish assemblage structure: Implications for environmental water management in a perennial river of the wet–dry tropics of northern Australia
Authors: Pusey Bradley J. , Douglas Michael , Olden Julian D. , Jackson Sue , Allsop Quentin , Kennard Mark J.
Published: June 2020

Environmental water management seeks to balance competing demands between the water needed to sustain human populations and their economic activities and that required to sustain functioning freshwater ecosystems and the species they support. It must be predicated on an understanding of the environmental, hydrological, and biological factors that determine the distribution and abundance of aquatic species.

The Daly River of the wet–dry tropics of northern Australia consists of a perennially flowing main stem and large tributaries, as well as many small to large naturally intermittent tributaries, and associated off‐channel wetlands. Increased groundwater abstraction to support irrigated agriculture during the dry season threatens to reduce dry‐season flows that maintain perenniality and persistence of freshwater fishes.

Fish assemblages were surveyed at 55 locations during the dry season over a 2‐year period with the goal of establishing the key landscape‐scale and local‐scale (i.e. habitat) drivers of fish species distribution.

Longitudinal (upstream/downstream) and lateral (river/floodplain) gradients in assemblage structure were observed with the latter dependent on the position in the river landscape. Underlying these gradients, stream flow intermittency influenced assemblage composition, species richness, and body size distributions. Natural constraints to dispersal were identified and their influence on assemblage structure was also dependent on position within the catchment.

Eight distinct assemblage types were identified, defined by differences in the abundance of species within five groups differing in functional traits describing body size, spawning requirements, and dispersal capacity. These functional groups largely comprised species widely distributed in northern Australia.

The results of the study are discussed with reference to the environmental flow needs of the Daly River and other rivers of northern Australia. The findings may also be applied to environmental flow management in savannah rivers elsewhere.