Search

Describes the crystal structure of dicarboxylatotriorganostannates. Chelating acetate groups; Negative and positive charges; Displacement ellipsoids; Covalent bonding of carboxylate ion and stannous atom.

The article presents a serologic report of dogs with H3N2 canine influenza virus (CIV) in Northeast China. The report found that 45 out of 224 canine sera and 166 of the 500 canine sera tested feral dogs and pet dogs were seropositive by nucleoprotein-enzyme-linked immunosorbent assay (NP-ELISA). The author comments that the data provided by this report is useful for small animal practitioners or public health policy makers to carry out measures of preventing the disease.

A single-layer zinc oxide (ZnO) nanorod array-based micro energy harvester was designed and integrated with a piezoelectric metacapacitor. The device presents outstanding low-frequency (1–10 Hz) mechanical energy harvesting capabilities. When compared with conventional pristine ZnO nanostructured piezoelectric harvesters or generators, both open-circuit potential and short-circuit current are significantly enhanced (up to 3.1 V and 124 nA cm−2) for a single mechanical knock (∼34 kPa). Higher electromechanical conversion efficiency (1.3 pC/Pa) is also observed. The results indicate that the integration of the piezoelectric metacapacitor is a crucial factor for improving the low-frequency energy harvesting performance. A double piezoelectric-driven mechanism is proposed to explain current higher output power, in which the metacapacitor plays the multiple roles of charge pumping, storing and transferring. An as-fabricated prototype device for lighting an LED demonstrates high power transference capability, with over 95% transference efficiency to the external load. [ABSTRACT FROM AUTHOR]

The booming development of DIW technology present an unprecedented prospect in energetic materials field and has attracted great interest due to its relative simplicity and high flexibility of manufacturing. Herein, a novel CL-20 based explosive ink formulation have been developed successfully for MEMS initiation systems via DIW technology. We designed PVA/GAP into an oil-in-water(O/W)emulsion, in the way that the aqueous solution of PVA as water phase, the ethyl acetate solution of GAP as oil phase, the combination of Tween 80 and SDS as emulsifier, BPS as a curing agent of GAP. The ideal formulation with good shear-thinning rheology properties and clear gel point was prepared using only 10 wt% emulsion. The dual-cured network formed during the curing process made the printed sample have good mechanical properties. The printed samples had satisfactory molding effect without cracks or fractures, the crystal form of CL-20 not changed and the thermal stability have improved. Deposition of explosive inks via DIW in micro-scale grooves had excellent detonation performances, which critical detonation size was 1 × 0.045 mm, detonation velocity was 7129 m/s and when the corner reaching 150° can still detonated stably. This study may open new avenues for developing binder systems in explosive ink formulations.

Abstract Genome synthesis endows scientists the ability of de novo creating genomes absent in nature, by thorough redesigning DNA sequences and introducing numerous custom features. However, the genome synthesis is a labor‐ and time‐consuming work, and thus it is a challenge to verify and quantify the synthetic genome rapidly and precisely. Thus, specific DNA sequences different from native genomic sequences are designed into synthetic genomes during synthesis, namely genomic markers. Genomic markers can be easily detected by PCR reaction, whole‐genome sequencing (WGS) and a variety of methods to identify the synthetic genome from native one. Here, we review types and applications of genomic markers utilized in synthetic genomes, with the hope of providing a guidance for future works.

Epitaxial growth, as a best strategy to attain a heterostructure with a well-defined and clean interlace, usually takes place on a planar substrate. In this paper, using a ZnO/SnO2 core-shell heterostructure as an example, we demonstrate the possibility of establishing a three-dimensional epitaxial interface between two materials with different crystal systems for the first time and show possible tailoring optical properties by building the heteroepitaxial crystal interface. The characterization results of element mapping, high-resolution transmission electron microscopy, and selected area electric diffraction reveal that the as-prepared ZnO/SnO2 heterostructure has a tetrapod-like ZnO core and a SnO2 shell with 15-30 nm, and their special epitaxial relation is (010)SnO2∥(0...110)ZnO and [100]SnO2∥[0001]ZnO. Such three-dimensional epitaxy between the ZnO core and SnO2 shell is quite different from the usual planar epitaxy or three- dimensional epitaxy between materials having the same crystal structure. A rational model of such complicated epitaxy has been proposed through investigating the certain structural comparability between the wurtzite ZnO and rutile SnO2 crystals. The as-prepared T-ZnO/SnO2 epitaxial heterostructure exhibits unique luminescence properties in contrast with individual tetrapod ZnO and SnO2 nanostructures, in which the epitaxial interlace induces new luminescence properties. This result may inspire great interest in exploring other complicated epitaxy systems and their potential applications in laser, gas sensor, solar energy conversion, photo catalysis, and nanodevices in the future. [ABSTRACT FROM AUTHOR]

Fungal infections pose a serious and growing threat to public health. These infections can be treated with antifungal drugs by killing hazardous fungi in the body. However, the resistance can develop over time when fungi are exposed to antifungal drugs by generating genomic variations, including mutation, aneuploidy, and loss of heterozygosity. The variations could reduce the binding affinity of a drug to its target or block the pathway through which drugs exert their activity. Here, we review genomic variation-mediating fluconazole resistance in the yeast Candida, with the hope of highlighting the functional consequences of genomic variations for the antifungal resistance.

The article presents a study that explores the plasmonic nanoreactors regulating selective oxidation by energetic electrons and nanoconfined thermal fields. It suggests a strategy to rationally use plasmonic nanostructures to optimize chemical processes, thereby achieving high yield with high selectivity at lower temperature under visible light illumination.

Manganese dioxide (MnO2) nanomaterials with two-dimensional (2D) layered birnessite structures are promising pseudocapacitive electrode materials. However, the effects of structural factors on their electrochemical performance is not fully understood. We synthesize alkali-free crystal water containing 2D layered birnessite MnO2 electrodes with controllable mass loading from 0.1 to 19.3 mg cm−2 to investigate the effects of electrode thickness and crystal water functions on crystal structure and pseudocapacitive behavior, to promote its industrialization. We find that the crystal water enlarges the interlayer space of birnessite MnO2 with electrolyte ions transported much more easily, resulting in higher specific capacitance of 702 F g−1 (70.2 mF cm−2) and excellent cycling stability of 20 000 charge–discharge cycles even at a mass loading of up to 10.8 mg cm−2. Such gains in specific capacitance are weakened significantly with raised mass loading. Thus, compared to a carbon cloth substrate, a carbon nanotube film with enhanced electron space transport capability presents better performance, indicating an effective strategy for higher mass loading cases. The present work sheds light on an efficient method for achieving high capacitance and mass loading together, for practical applications. [ABSTRACT FROM AUTHOR]

Genome structural variation can play an important functional role in phenotypic diversity. Here the authors use the SCRaMbLE system on a ring synthetic chromosome V to generate complex rearrangements distinct from a rearranged linear chromosome.

The SCRaMbLE system integrated into Sc2.0’s synthetic yeast chromosome project allows rapid strain evolution. Here the authors use a genetic logic gate to control induction of recombination in a haploid and diploid yeast carrying synthetic chromosomes.

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is the etiological agent responsible for the global COVID-19 (coronavirus disease 2019) outbreak. The main protease of SARS-CoV-2, Mpro, is a key enzyme that plays a pivotal role in mediating viral replication and transcription. We designed and synthesized two lead compounds (11a and 11b) targeting Mpro. Both exhibited excellent inhibitory activity and potent anti–SARS-CoV-2 infection activity. The x-ray crystal structures of SARS-CoV-2 Mpro in complex with 11a or 11b, both determined at a resolution of 1.5 angstroms, showed that the aldehyde groups of 11a and 11b are covalently bound to cysteine 145 of Mpro. Both compounds showed good pharmacokinetic properties in vivo, and 11a also exhibited low toxicity, which suggests that these compounds are promising drug candidates. [ABSTRACT FROM AUTHOR]

The effect of hot-water blanching (HWB) on drying characteristics and product qualities of dried apple slices with the novel integrated freeze-drying (NIFD) process was investigated by comparing with 3 different FD methods. Compared with the NIFD process without HWB pretreatment (VF-FD), the NIFD process with HWB pretreatment (HWB-VF-FD) resulted in a significantly higher mass loss and more sufficient freezing in vacuum-frozen samples, significantly higher rehydration ratio (RR), higher shrinkage ratio (SR), smaller Vitamin C (VC) content and lower hardness and better apparent shape in freeze-dried samples, and fewer change to the color of the dried or rehydrated samples (p

The original version of this Article omitted a declaration from the Competing Interests statement, which should have included the following: ‘J.D.B. is a founder and Director of the following: Neochromosome, Inc., the Center of Excellence for Engineering Biology, and CDI Labs, Inc. and serves on the Scientific Advisory Board of the following: Modern Meadow, Inc., Recombinetics, Inc., and Sample6, Inc.’. This has now been corrected in both the PDF and HTML versions of the Article.

The title compound, [Zn(C12H6O4)(C3H10N2)2] n, has been prepared from zinc(II), naphthalene-2,6-dicarboxylic acid (H2napdc) and 1,3-propyl­enediamine (pren). The Zn atom lies on a crystallographic centre of symmetry and is coordinated by two monodentate naphthalene-2,6-dicarboxyl­ate ligands and two chelating 1,3-propyl­enediamine ligands in a distorted octa­hedral environment. The naphthalene-2,6-dicarboxyl­ate ligands link the Zn atoms, forming a one-dimensional chain structure. [ABSTRACT FROM AUTHOR]

Fe electrodeposition on Au(111) and Au(100) in BMIBF4 ionic liquid is found to form hitherto unreported shape–ordered nanoscale morphologies of pseudorods and pseudosquare rings, respectively, both composed of grains of 4–7 nm. The manner of growth of the square rings is a ring–on–ring structure with enlarging side length and slightly protruding four corners. The generality of the growth mechanism is verified by the formation of almost exactly the same shape–ordered Fe nanostructures on Pt, i.e., pseudorod structure on Pt(111) and pseudosquare rings Pt(100). These structures are explained within the framework of magnetostatic interactions of spontaneously magnetized grains under crystallographic constraint of the substrate surface, which result in an antiparallel arrangement in magnetization of the grains at pseudorods and magnetic flux closure at the pseudosquare rings. The closed magnetic flux further leads to magnetic field–enhanced growth at the four corners and the outer peripheries of the pseudosquare rings. The observed shape–ordering of the Fe thin film serves as a paradigm of magnetostatic coupling, in which the roles of ionic liquid as surfactant and magnetic media may not be underestimated. The present work adds a new dimension to electrodeposition in ionic liquid, by which new magnetic film structures may be expected. [ABSTRACT FROM AUTHOR]

Neutral inorganic molecules are generally weak in surface adsorption and intermolecular interactions. Self-assembly of such types of molecule would provide valuable information about various interactions. At electrochemical interfaces, the relative strength of these interactions may be modified through control of electrode potential and electrolyte, which may lead to the discovery of new structures and new phenomena. However, studies of this nature are as yet lacking. In this work, we consider the covalent-bound semimetal compound molecules, XCl3 (X = Sb, Bi), as model systems of neutral inorganic molecules to investigate their self-assembly at electrochemical interfaces under a high ionic atmosphere. To fulfill such investigations, in situ STM and cyclic voltammetry are employed, and comparative experiments are performed on Au(111) in ionic liquids as well as aqueous solutions with high ionic strength. In the room temperature ionic liquid of 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF4), potential-dependent partial charge transfer between the Au surface and XCl3 molecules creates a molecule-surface interaction and provides the driving force for adsorption of the molecules. Supramolecular aggregations of adsorbed XCl3 are promoted through chlorine-based short-range intermolecular correlation under crystallographic constraint, while repulsive Coulombic interactions created between the partially charged aggregations facilitate their long-range ordering. For SbCl3 molecules, hexagonally arranged 6- or 7-member clusters are formed at 0.08 to -0.2 V (vs Pt), which assemble into a secondary (√31 × √31)R8.9° structure. For BiCl3 molecules, both the 6-membered hexagonal and 3-membered trigonal clusters are formed in the narrow potential range -0.3 to -0.35 V, and are also arranged into an ordered secondary structure. Comparative studies were performed with SbCl3 in concentrated aqueous solutions containing 2 M HCl to simulate the strong ionic strength of the ionic liquid. Almost identical 6-/7-member clusters and long-range (√31 × √31)R8.9° structure are observed at -0.1 V, demonstrating the crucial role of strong ionic strength in such supramolecular aggregations. However, such supramolecular structures are modified and eventually destroyed as ionic strength is further increased by addition of NaClO4 up to 6 M. The destructive changes of the supramolecular structures are attributed to the alteration of ion distribution in the double layer from cation-rich to anion-rich at increasing NaClO4 concentration. This modifies and eventually breaks the balance of intermolecular and molecule-electrolyte interactions. Finally, the dynamic behavior of the SbCl3 assembly is investigated down to molecular level. It has been demonstrated that the initial stage of assembly follows a two-dimensional nucleation and growth mechanism and has a potential-dependent rate that is closely related to the surface mobility of the SbCl3 clusters. There is a probability that clusters can escape from an existing assembly domain or insert into a vacancy in such a domain while they can also relax with central or ring members in a dynamic fashion. These phenomena indirectly reflect the dynamic properties of cations from electrolytes at the interface. The rich information contained in the self-assembly behavior of SbCl3 and BiCl3 demonstrates that neutral inorganic molecules can be employed for fundamental studies of a variety of interesting issues, especially the interplay of various interfacial interactions. [ABSTRACT FROM AUTHOR]

The article discusses the result of a study concerning epitaxial growth of heterogenous metal nanocrystals from gold nano-octahedra to palladium and silver nanocubes. The study found that three binary metallic core-shell nanocrystals have been successfully synthesized in high yield by a two-step seed-mediated method in a simple aqueous system.

We report here the complete genomic sequence of a novel porcine circovirus type 2 (PCV2) strain, which is supposed to be the result of natural genetic recombination between the ORF1 gene of genotype PCV2b-1B and the ORF2 gene of PCV2b-1C. Further analyses revealed that this novel PCV2 strain arose from recombination between PCV2a and PCV2b strains within the ORF2 gene. To our knowledge, this is the first report of both inter- and intragenotype PCV2 gene rearrangement in the field, and it will help in understanding the epidemiology and molecular characteristics of porcine circovirus type 2(PCV2) in southern China. [ABSTRACT FROM AUTHOR]

We report here the complete genomic sequence of a novel duck hepatitis A virus (DHAV) isolated from mixed infections with DHAV type 1 (DHAV-1) and DHAV-3 in ducklings in Southern China. The whole nucleotide sequence had the highest homology with the sequence of DHAV-3 (GenBank accession number DQ812093) (96.2%). To our knowledge, this is the first report of gene rearrangement between DHAV-1 and DHAV-3, and it will help to understand the epidemiology and molecular characteristics of duck hepatitis A virus in Southern China. [ABSTRACT FROM AUTHOR]

Objective: Chinese pediatricians are working on the front line to fight COVID-19. They have published a great amount of first-hand clinical data. Collecting their data and forming a large sample for analysis is more conducive to the recognition, prevention and treatment of coronavirus disease 2019 in children. The epidemic prevention and control experience of Chinese pediatricians should be shared with the world., Methods: By searching Chinese and English literature, the data of 406 children with COVID-19 in China were analyzed., Results: It was found that the clustered incidence of children's families is a dynamic transmission feature; the incidence is low; asymptomatic infections and mild cases account for 44.8%, with only 7 cases of critical illness; laboratory examination of lymphocyte counts is not reduced, as it is for adults; chest CT findings are less severe than those for adults. These presentations are the clinical features of COVID-19 in children. Only 55 of the 406 cases were tested by anal swab for virus nucleic acid, 45 of which were positive, accounting for 81.8% of stool samples., Conclusion: There are more children than adults with asymptomatic infections, milder conditions, faster recovery, and a better prognosis. Some concealed morbidity characteristics also bring difficulties to the early identification, prevention and control of COVID-19. COVID-19 screening is needed in the pediatric fever clinic, and respiratory and digestive tract nucleic acid tests should be performed. Efforts should be made to prevent children from becoming a hidden source of transmission in kindergartens, schools or families. Furthermore, China's experience in treating COVID-19 in children has led to faster recovery of sick children., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest, (Copyright © 2020 The British Infection Association. Published by Elsevier Ltd. All rights reserved.)