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1.
Nature ; 599(7884): 222-228, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34587621

RESUMEN

The transition metal kagome lattice materials host frustrated, correlated and topological quantum states of matter1-9. Recently, a new family of vanadium-based kagome metals, AV3Sb5 (A = K, Rb or Cs), with topological band structures has been discovered10,11. These layered compounds are nonmagnetic and undergo charge density wave transitions before developing superconductivity at low temperatures11-19. Here we report the observation of unconventional superconductivity and a pair density wave (PDW) in CsV3Sb5 using scanning tunnelling microscope/spectroscopy and Josephson scanning tunnelling spectroscopy. We find that CsV3Sb5 exhibits a V-shaped pairing gap Δ ~ 0.5 meV and is a strong-coupling superconductor (2Δ/kBTc ~ 5) that coexists with 4a0 unidirectional and 2a0 × 2a0 charge order. Remarkably, we discover a 3Q PDW accompanied by bidirectional 4a0/3 spatial modulations of the superconducting gap, coherence peak and gap depth in the tunnelling conductance. We term this novel quantum state a roton PDW associated with an underlying vortex-antivortex lattice that can account for the observed conductance modulations. Probing the electronic states in the vortex halo in an applied magnetic field, in strong field that suppresses superconductivity and in zero field above Tc, reveals that the PDW is a primary state responsible for an emergent pseudogap and intertwined electronic order. Our findings show striking analogies and distinctions to the phenomenology of high-Tc cuprate superconductors, and provide groundwork for understanding the microscopic origin of correlated electronic states and superconductivity in vanadium-based kagome metals.

2.
Nano Lett ; 24(20): 6023-6030, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38739284

RESUMEN

Construction of diatomic rotors, which is crucial for artificial nanomachines, remains challenging due to surface constraints and limited chemical design. Here we report the construction of diatomic Cr-Cs and Fe-Cs rotors where a Cr or Fe atom switches around a Cs atom at the Sb surface of the newly discovered kagome superconductor CsV3Sb5. The switching rate is controlled by the bias voltage between the rotor and scanning tunneling microscope (STM) tip. The spatial distribution of rates exhibits C2 symmetry, possibly linked to the symmetry-breaking charge orders of CsV3Sb5. We have expanded the rotor construction to include different transition metals (Cr, Fe, V) and alkali metals (Cs, K). Remarkably, designed configurations of rotors are achieved through STM manipulation. Rotor orbits and quantum states are precisely controlled by tuning the inter-rotor distance. Our findings establish a novel platform for the controlled fabrication of atomic motors on symmetry-breaking quantum materials, paving the way for advanced nanoscale devices.

3.
Nano Lett ; 23(8): 3274-3281, 2023 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-37014819

RESUMEN

Landau quantization associated with the quantized cyclotron motion of electrons under magnetic field provides the effective way to investigate topologically protected quantum states with entangled degrees of freedom and multiple quantum numbers. Here we report the cascade of Landau quantization in a strained type-II Dirac semimetal NiTe2 with spectroscopic-imaging scanning tunneling microscopy. The uniform-height surfaces exhibit single-sequence Landau levels (LLs) at a magnetic field originating from the quantization of topological surface state (TSS) across the Fermi level. Strikingly, we reveal the multiple sequence of LLs in the strained surface regions where the rotation symmetry is broken. First-principles calculations demonstrate that the multiple LLs attest to the remarkable lifting of the valley degeneracy of TSS by the in-plane uniaxial or shear strains. Our findings pave a pathway to tune multiple degrees of freedom and quantum numbers of TMDs via strain engineering for practical applications such as high-frequency rectifiers, Josephson diode and valleytronics.

4.
J Environ Manage ; 360: 121185, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38788407

RESUMEN

Chlorophyll fluorescence is the long-wave light released by the residual energy absorbed by vegetation after photosynthesis and dissipation, which can directly and non-destructively reflect the photosynthetic state of plants from the perspective of the mechanism of photosynthetic process. Moso bamboo has a substantial carbon sequestration ability, and leaf-expansion stage is an important phenological period for carbon sequestration. Gross primary production (GPP) is a key parameter reflecting vegetation carbon sequestration process. However, the ability of chlorophyll fluorescence in moso bamboo to explain GPP changes is unclear. The research area of this study is located in the bamboo forest near the flux station of Anji County, Zhejiang Province, where an observation tower is built to monitor the carbon flux and meteorological change of bamboo forest. The chlorophyll fluorescence physiological parameters (Fp) and fluorescence yield (Fy) indices were measured and calculated for the leaves of newborn moso bamboo (I Du bamboo) and the old leaves of 4- to 5-year-old moso bamboo (Ⅲ Du bamboo) during the leaf-expansion stage. The chlorophyll fluorescence in response to the environment and its effect on carbon flux were analyzed. The results showed that: Fv/Fm, Y(II) and α of Ⅰ Du bamboo gradually increased, while Ⅲ Du bamboo gradually decreased, and FYint and FY687/FY738 of Ⅰ Du bamboo were higher than those of Ⅲ Du bamboo; moso bamboo was sensitive to changes in air temperature(Ta), relative humidity(RH), water vapor pressure(E), soil temperature(ST) and soil water content (SWC), the Fy indices of the upper, middle and lower layers were significantly correlated with Ta, E and ST; single or multiple vegetation indices were able to estimate the fluorescence yield indices well (all with R2 greater than 0.77); chlorophyll fluorescence (Fp and Fy indices) of Ⅰ Du bamboo and Ⅲ Du bamboo could explain 74.4% and 72.7% of the GPP variation, respectively; chlorophyll fluorescence and normalized differential vegetation index of the canopy (NDVIc) could estimate GPP well using random forest (Ⅰ Du bamboo: r = 0.929, RMSE = 0.069 g C·m-2; Ⅲ Du bamboo: r = 0.899, RMSE = 0.134 g C·m-2). The results of this study show that chlorophyll fluorescence can provide a basis for judging the response of moso bamboo to environmental changes and can well explain GPP. This study has important scientific significance for evaluating the potential mechanisms of growth, stress feedback and photosynthetic carbon sequestration of bamboo.


Asunto(s)
Clorofila , Fotosíntesis , Hojas de la Planta , Clorofila/metabolismo , Hojas de la Planta/metabolismo , Fluorescencia , Poaceae/metabolismo , Poaceae/crecimiento & desarrollo , Secuestro de Carbono , Carbono/metabolismo
5.
Small ; 19(15): e2207615, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36605013

RESUMEN

Next-generation imaging systems require photodetectors with high sensitivity, polarization sensitivity, miniaturization, and integration. By virtue of their intriguing attributes, emerging 2D materials offer innovative avenues to meet these requirements. However, the current performance of 2D photodetectors is still below the requirements for practical application owing to the severe interfacial recombination, the lack of photoconductive gain, and insufficient photocarrier collection. Here, a tunneling dominant imaging photodetector based on WS2 /Te heterostructure is reported. This device demonstrates competitive performance, including a remarkable responsivity of 402 A W-1 , an outstanding detectivity of 9.28 × 1013 Jones, a fast rise/decay time of 1.7/3.2 ms, and a high photocurrent anisotropic ratio of 2.5. These outstanding performances can be attributed to the type-I band alignment with carrier transmission barriers and photoinduced tunneling mechanism, allowing reduced interfacial trapping effect, effective photoconductive gains, and anisotropic collection of photocarriers. Significantly, the constructed photodetector is successfully integrated into a polarized light imaging system and an ultra-weak light imaging system to illustrate the imaging capability. These results suggest the promising application prospect of the device in future imaging systems.

6.
Mol Phylogenet Evol ; 186: 107842, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37321361

RESUMEN

Distinct hosts have been hypothesized to possess the potential for affecting species differentiation and genome evolution of parasitic organisms. However, what host shift history is experienced by the closely related parasites and whether disparate evolution of their genomes occur remain largely unknown. Here, we screened horizontal gene transfer (HGT) events in a pair of sister species of holoparasitic Boschniakia (Orobanchaceae) having obligate hosts from distinct families to recall the former host-parasite associations and performed a comparative analysis to investigate the difference of their organelle genomes. Except those from the current hosts (Ericaceae and Betulaceae), we identified a number of HGTs from Rosaceae supporting the occurrence of unexpected ancient host shifts. Different hosts transfer functional genes which changed nuclear genomes of this sister species. Likewise, different donors transferred sequences to their mitogenomes, which vary in size due to foreign and repetitive elements rather than other factors found in other parasites. The plastomes are both severely reduced, and the degree of difference in reduction syndrome reaches the intergeneric level. Our findings provide new insights into the genome evolution of parasites adapting to different hosts and extend the mechanism of host shift promoting species differentiation to parasitic plant lineages.


Asunto(s)
Genoma de Plastidios , Orobanchaceae , Humanos , Filogenia , Orobanchaceae/genética , Genes de Plantas , Secuencias Repetitivas de Ácidos Nucleicos , Transferencia de Gen Horizontal
7.
Chemistry ; 29(5): e202202594, 2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36318097

RESUMEN

The development of circularly polarized thermally activated delayed fluorescence (CP-TADF) luminogens with stimuli-response characteristics remains challenging. Herein, a pair of organic enantiomers, S-CzTA and R-CzTA, with aggregation-induced emission properties, have been successfully developed by introducing chiral 1,2,3,4-tetrahydronaphthalene and carbazole to phthalimide. They present CP-TADF properties in toluene solutions, giving dissymmetric factors of 0.84×10-3 and -1.03×10-3 , respectively. In the crystalline state, both S-CzTA and R-CzTA can emit intense blue TADF and produce very bright sky-blue mechanoluminescence (ML) and remarkable mechanofluorochromism (MFC) under the stimuli of mechanical force. Single-crystal analysis and theoretical calculation results suggest that their ML activities are probably associated with their chiral and polar molecular structures and unique non-centrosymmetric molecular packing modes. Furthermore, the MFC properties of the enantiomers likely originate from the destruction of crystal structure, leading to the planarization of molecular conformation. This work may provide helpful guidance for developing new CP-TADF materials with force-stimuli-responsive properties.


Asunto(s)
Tetrahidronaftalenos , Fluorescencia
8.
Artículo en Inglés | MEDLINE | ID: mdl-36884384

RESUMEN

A endospore-forming bacterium, designated strain KQZ6P-2T, was isolated from surface-sterilized bark of the mangrove plant Kandelia candel, collected from Maowei Sea Mangrove Nature Reserve in Guangxi Zhuang Autonomous Region, China. Strain KQZ6P-2T was able to grow at NaCl concentrations in the range of 0-3 % (w/v) with optimum growth at 0-1 % (w/v) NaCl. Growth occurred at 20-42 °C (optimal growth at 30-37 °C) and pH 5.5-6.5 (optimal growth at pH 6.5). The 16S rRNA gene sequence similarity between strain KQZ6P-2T and its closest phylogenetic neighbour Paenibacillus chibensis JCM 9905T was 98.2 %. Phylogenetic analyses using 16S rRNA gene sequences showed that strain KQZ6P-2T formed a distinct lineage with Paenibacillus chibensis JCM 9905T. The draft genome of strain KQZ6P-2T was 5 937 633 bp in size and its DNA G+C content was 47.2mol%. Comparative genome analysis revealed that the average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values among strain KQZ6P-2T and its related species were below the cut-off levels of 95, 70 and 95.5%, respec-tively. The cell-wall peptidoglycan of strain KQZ6P-2T contained meso-diaminopimelic acid as the diagnostic diamino acid. Major cellular fatty acids were anteiso-C15:0 and C16:0. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified aminophospholipids, four unidentified phospholipids, an unidentified aminolipid and five unidentified lipids. Based on phylogenetic, phenotypic and chemotaxonomic data, strain KQZ6P-2T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus mangrovi sp. nov. is proposed. The type strain is KQZ6P-2T (=MCCC 1K07172T =JCM 34931T).


Asunto(s)
Paenibacillus , Rhizophoraceae , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , Cloruro de Sodio , Corteza de la Planta , ADN Bacteriano/genética , Composición de Base , China , Técnicas de Tipificación Bacteriana , Análisis de Secuencia de ADN , Fosfolípidos/química , Hibridación Genómica Comparativa
9.
Inorg Chem ; 62(1): 147-159, 2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36565286

RESUMEN

MOF/inorganic nanocomposites combine the advantages of each component. Herein, two MOF/metal selenite nanocomposites, Co-NH2-BDC/CoSeO3·H2O and Co-BDC/CoSeO3·H2O, are prepared on nickel foam through a facile two-step hydrothermal method, which inherit the 2D morphology and porosity properties of their MOF precursors. Furthermore, during the electrochemical activation process, the crystallized nanocomposites can easily transform into amorphous structures in a short time of 20 min in the presence of an electric field, similar to CoSeO3·H2O. Due to amorphization, the electrochemical performance of the two nanocomposites is much enhanced relative to that of their MOF precursors. Specifically, the areal capacitances of Co-NH2-BDC/CoSeO3·H2O and Co-BDC/CoSeO3·H2O are 5.35 and 10.65 F·cm-2 at 2 mA·cm-2, respectively. The assembled asymmetric supercapacitor (ASC) using Co-NH2-BDC/CoSeO3·H2O as positive electrodes delivers an energy density of 0.207 mWh·cm-2 at a power density of 0.799 mW·cm-2 with outstanding cycling stability (93% capacity retention after 5000 cycles). Using Co-BDC/CoSeO3·H2O as positive electrodes, the ASC can reach a high energy density of 0.483 mWh·cm-2 at a power density of 0.741 mW·cm-2 and 84% capacity retention after 5000 cycles. This work provides an efficient strategy for constructing MOF/metal selenite nanocomposites for energy storage and conversion.

10.
Nano Lett ; 22(3): 1017-1023, 2022 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-35041439

RESUMEN

The uncontrolled zinc dendrite growth during plating leads to quick battery failure, which hinders the widespread applications of aqueous zinc-ion batteries. The growth of Zn dendrites is often promoted by the "tip effect". In this work, we propose a generate strategy to eliminate the "tip effect" by utilizing the electrostatic shielding effect, which is achieved by coating Zn anodes with magnetron sputtered Al-based alloy protective layers. The Al can form a surface insulating Al2O3 layer and by manipulating the Al content of Zn-Al alloy films, we are able to control the strength of the electrostatic shield, therefore realizing a long lifespan of Zn anodes up to 3000 h at a practical operating condition of 1.0 mA cm-2 and 1.0 mAh cm-2. In addition, the concept can be extended to other Al-based systems such as Ti-Al alloy and achieve enhanced stability of Zn anodes, demonstrating the generality and efficacy of our strategy.

11.
Angew Chem Int Ed Engl ; 62(7): e202217284, 2023 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-36512442

RESUMEN

In this work, an efficient polymer-based organic afterglow system, which shows reversible photochromism, switchable ultralong organic phosphorescence (UOP), and prominent water and chemical resistance simultaneously, has been developed for the first time. By doping phenoxazine (PXZ) and 10-ethyl-10H-phenoxazine (PXZEt) into epoxy polymers, the resulting PXZ@EP-0.25 % and PXZEt@EP-0.25 % films show unique photoactivated UOP properties, with phosphorescence quantum yields and lifetimes up to 10.8 % and 845 ms, respectively. It is found that the steady-state luminescence and UOP of PXZ@EP-0.25 % are switchable by light irradiation and thermal annealing. Moreover, the doped films can still produce conspicuous UOP after soaking in water, strong acid and base, and organic solvents for more than two weeks, exhibiting outstanding water and chemical resistance. Inspired by these exciting results, the PXZ@EP-0.25 % has been successfully exploited as an erasable transparent film for light printing.

12.
BMC Plant Biol ; 22(1): 444, 2022 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-36114450

RESUMEN

BACKGROUND: Orobanchaceae is the only flowering plant family with species from free-living nonparasite, hemi-parasite to holoparasite, making it an ideal system for studying the evolution of parasitism. However, both plastid and mitochondrial genome have been sequenced in only few parasitic species in Orobanchaceae. Therefore, further comparative study is wanted to investigate the impact of holoparasitism on organelle genomes evolution between close relatives. Here, we sequenced organelle genomes and transcriptome of holoparasitic Christisonia kwangtungensis and compared it with its closely related groups to analyze similarities and differences in adaption strategies to the holoparasitic lifestyle. RESULTS: The plastid genome of C. kwangtungensis has undergone extensive pseudogenization and gene loss, but its reduction pattern is different from that of Aeginetia indica, the close relative of C. kwangtungensis. Similarly, the gene expression detected in the photosynthetic pathway of these two genera is different. In Orobanchaceae, holoparasites in Buchnereae have more plastid gene loss than Rhinantheae, which reflects their longer history of holoparasitism. Distinct from severe degradation of the plastome, protein-coding genes in the mitochondrial genome of C. kwangtungensis are relatively conserved. Interestingly, besides intracellularly transferred genes which are still retained in its plastid genome, we also found several horizontally transferred genes of plastid origin from diverse donors other than their current hosts in the mitochondrial genome, which probably indicate historical hosts. CONCLUSION: Even though C. kwangtungensis and A. indica are closely related and share severe degradation of plastome, they adapt organelle genomes to the parasitic lifestyle in different ways. The difference between their gene loss and gene expression shows they ultimately lost photosynthetic genes but through different pathways. Our study exemplifies how parasites part company after achieving holoparasitism.


Asunto(s)
Genoma Mitocondrial , Genoma de Plastidios , Orobanchaceae , Genoma Mitocondrial/genética , Genoma de Plastidios/genética , Orobanchaceae/genética , Plastidios/genética , Análisis de Secuencia de ADN
13.
Small ; 18(21): e2200006, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35261146

RESUMEN

Rechargeable zinc-ion batteries (ZIBs) have shown great potential as an alternative to lithium-ion batteries. The ZIBs utilize Zn metal as the anode, which possesses many advantages such as low cost, high safety, eco-friendliness, and high capacity. However, on the other hand, the Zn anode also suffers from many issues, including dendritic growth, corrosion, and passivation. These issues are largely related to the surface and interface properties of the Zn anode. Many efforts have therefore been devoted to the modification of the Zn anode, aiming to eliminate the above-mentioned problems. This review gives a comprehensive summary on the mechanism behind these issues as well as the recent progress on Zn anode modification with focus on the strategies of surface and interface engineering, covering the design and application of both the Zn anode supports and surface protective layers, along with abundant examples. In addition, the promising research directions and perspective on these strategies are also presented.

14.
Artículo en Inglés | MEDLINE | ID: mdl-35353675

RESUMEN

A new endophytic bacterium, designated strain MQZ13P-4T was isolated from Sonneratia apetala collected from Maowei sea Mangrove Nature Reserve in Guangxi Zhuang Autonomous Region, PR China. The 16S rRNA gene sequence similarity between strain MQZ13P-4T and its closest phylogenetic neighbour Jiella endophytica CBS5Q-3T was 97.9 %. Phylogenetic analyses using 16S rRNA gene sequences and whole-genome sequences showed that strain MQZ13P-4T formed a distinct lineage with Jiella endophytica CBS5Q-3T, Jiella pacifica 40Bstr34T and Jiella aquimaris JCM 30119T. The draft genome of strain MQZ13P-4T was 5 153 243 bp in size and its DNA G+C content was 68.1 mol%. Comparative genome analysis revealed that the average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values among strain MQZ13P-4T and other related species were below the cut-off levels of 95, 70 and 95.5 %, respectively. The cell-wall peptidoglycan of strain MQZ13P-4T contained meso-diaminopimelic acid as the diagnostic diamino acid. The respiratory quinone was Q-10. The major cellular fatty acid was C18 : 1 ω7c. The polar lipids comprised phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two unidentified aminolipids and two unidentified lipids. Strain MQZ13P-4T had a typical chemical compositions of fatty acids, lipids, quinones and diagnostic diamino acid for Jiella species, but could be distinguished from known species of the genus Jiella. Based on polyphasic evidence, strain MQZ13P-4T represents novel species of the genus Jiella, for which the name Jiella sonneratiae sp. nov. is proposed. The type strain is MQZ13P-4T (=CGMCC 1.18727T=JCM 34333T).


Asunto(s)
Ácidos Grasos , Corteza de la Planta , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Fosfolípidos/química , Filogenia , Corteza de la Planta/microbiología , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
15.
J Strength Cond Res ; 36(4): 941-947, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35319000

RESUMEN

ABSTRACT: Huang, Z-H, Ma, CZ-H, Wang, L-K, Wang, X-Y, Fu, S-N, and Zheng, Y-P. Real-time visual biofeedback via wearable ultrasound imaging can enhance the muscle contraction training outcome of young adults. J Strength Cond Res 36(4): 941-947, 2022-Real-time ultrasound imaging (RUSI) can serve as visual biofeedback to train deep muscle contraction in clinical rehabilitative settings. However, its effectiveness in resistance training in sports/fitness fields remains unexplored. This article introduced a newly developed wearable RUSI system that provided visual biofeedback of muscle thickening and movement and reported its effectiveness in improving the training outcomes of muscle thickness change (%) during dynamic contraction. Twenty-five healthy young men participated and performed pec fly exercise both with and without RUSI biofeedback. Statistical analysis was conducted to examine the reliability of the measurements and the immediate effects of (a) RUSI biofeedback of muscle contraction and (b) training intensity (50 vs. 80% of 1-repetition maximum [1RM]) on the pectoralis major (PMaj) thickness change measured by ultrasound images. In addition to significantly high inter-contraction reliability (ICC3,1 > 0.97), we observed significantly increased PMaj thickness change for both training intensities upon receiving biofeedback in subjects, compared with without biofeedback (p < 0.001). We also observed significantly larger PMaj thickness change at 80% of 1RM compared with 50% of 1RM (p = 0.023). The provision of visual biofeedback using RUSI significantly enlarged the magnitude of PMaj thickness change during pec fly exercises, potentially indicating that RUSI biofeedback could improve the ability of targeted muscle contraction of PMaj in healthy young adults. To our knowledge, this study has pioneered in applying RUSI as a form of biofeedback during weight training and observed positive effectiveness. Future iterations of the technique will benefit more subject groups, such as athletes and patients with neuromuscular disorders.


Asunto(s)
Contracción Muscular , Dispositivos Electrónicos Vestibles , Biorretroalimentación Psicológica , Humanos , Contracción Muscular/fisiología , Reproducibilidad de los Resultados , Ultrasonografía/métodos , Adulto Joven
16.
Antonie Van Leeuwenhoek ; 114(9): 1431-1442, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34263387

RESUMEN

A novel endophytic actinomycete, designated strain BSK3Z-2 T, was isolated from a surface-sterilised branch of Avicennia mariana from Shankou Mangrove Nature Reserve, Guangxi Zhuang Autonomous Region, China. Cells were observed to be Gram-stain positive, aerobic, asporogenous and rod-shaped. Strain BSK3Z-2 T was found to grow optimally at 30 °C, pH 7.0 and in the presence of 1% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BSK3Z-2 T belongs to the genus Phycicoccus and has high 16S rRNA gene sequence similarity of 98.1% with Phycicoccus endophyticus IP6SC6T. Phylogenetic analysis based on the genome of strain BSK3Z-2 T was performed by extracting and aligning 39 conserved proteins and 88 housekeeping genes, which further confirmed the phylogenetic assignment of strain BSK3Z-2 T. The draft genome of strain BSK3Z-2 T is 3.54 Mbp with a DNA G + C content of 73.8%. The average nucleotide identity (ANI), amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values between strain BSK3Z-2 T and species of genus Phycicoccus were 73.8-85.6%, 64.5-75.9% and 19.5-23.8%, respectively, which are below the standard cut-off values for bacterial species delineation. Strain BSK3Z-2 T contains MK-8(H4) as the dominant menaquinone. The cell wall peptidoglycan contains meso-diaminopimelic acid. The polar lipids profile of strain BSK3Z-2 T was found to contain diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The predominant fatty acids were identified as C15:0, C17:0, iso-C16:0 and C17:1ω8c. Comparing the phenotypic and phylogenetic features of the strain BSK3Z-2 T and related taxa, strain BSK3Z-2 T is concluded to represent a novel species of the genus Phycicoccus, for which the name Phycicoccus avicenniae sp. nov. is proposed. The type strain is BSK3Z-2 T (= CGMCC 1.18743 T = JCM 34335 T).


Asunto(s)
Actinobacteria , Avicennia , Actinobacteria/genética , Técnicas de Tipificación Bacteriana , China , ADN Bacteriano/genética , Ácidos Grasos/análisis , Fosfolípidos/análisis , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Microbiología del Suelo
17.
Antonie Van Leeuwenhoek ; 114(10): 1565-1574, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34346001

RESUMEN

A Gram-stain-positive, non-motile, endospore-forming, rod-shaped and aerobic bacterium was isolated from surface-sterilized branch of Aegiceras corniculatum in Guangxi Zhuang Autonomous Region, China. The isolate, designated strain 165T, grew at 20-45 °C (optimum, 30 °C), pH 6.0-7.0 (optimum, 6.0) and with 0-3 % (w/v) NaCl (optimum, 1 %). The major respiratory quinone was MK-7 and the cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid and an unidentified glycolipid. The major fatty acids were iso-C15:0, anteiso-C15:0 and iso-C16:0. On the basis of 16 S rRNA gene sequence and multiple genes of conserved core proteins analysis, strain 165T was a member of the genus Ectobacillus. Its closest phylogenetic neighbor was Ectobacillus panaciterrae Gsoil 1517T, with sequence similarity of 97.1 %. The average nucleotide identity value between strain 165T and type strain of Ectobacillus panaciterrae was 73.0 %. The estimated DDH value between strain 165T and type strain of Ectobacillus panaciterrae was 19.7 %. The genome of strain 165T was 3, 545, 051 bp long with a DNA G + C content of 38.2 % and encodes 3459 predicted proteins, 25 rRNAs, 87 tRNAs and 5 ncRNA. The genome of strain 165T comprised gene clusters of type 3 PKS, terpene, betalactone and lanthipeptide-class-ii for secondary metabolites. Phenotypic, chemotaxonomic and phylogenetic analyses supported the strain 165T as a representative of a novel species of the genus Ectobacillus, for which the name Ectobacillus aegiceratis sp. nov. is proposed, with strain 165T (= JCM 33,414T = CGMCC 1.13742T) as the type strain.


Asunto(s)
Fosfolípidos , Primulaceae , Técnicas de Tipificación Bacteriana , China , ADN Bacteriano/genética , Ácidos Grasos/análisis , Fosfolípidos/análisis , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
18.
Antonie Van Leeuwenhoek ; 114(10): 1633-1645, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34333698

RESUMEN

A Gram-stain negative, non-motile, brilliant yellow and non-spore forming, coccoid- or short rod-shaped bacterium, designated strain KSK16Y-1T, was isolated from surface-sterilised leaf of Rhizophora stylosa collected from Shankou Mangrove Nature Reserve, Guangxi Zhuang Autonomous Region, China. Genome of strain KSK16Y-1T is 4.93 Mb with 68.1% DNA G + C content and encoded 4359 predicted proteins, 4 rRNAs, 45 tRNAs and 4 ncRNA. Comparative 16S rRNA gene sequence analysis showed that the strain KSK16Y-1T has 98.1%, 97.9% and 96.9% 16S rRNA gene similarities with Jiella aquimaris JCM 30119T, J. endophytica CBS5Q-3T and J. pacifica 40Bstr34T, respectively. Whole-genome comparisons between strain KSK16Y-1T and J. aquimaris 22II-16-19i, J. endophytica CBS5Q-3T, J. pacifica 40Bstr34T, using average nucleotide identity (ANI) values (< 82.0%) and digital DNA-DNA hybridization (dDDH) values (< 25.1%), confirmed low genome relatedness. Strain KSK16Y-1T grew at 20-30 °C (optimum, 30 °C), pH 6.0-11.0 (optimum, pH 6.0-7.0) and with 0-10% (w/v) NaCl (optimum, 0-2%). Cell wall contained meso-diaminopimelic acid and the major fatty acid was C18:1ω7c. The polar lipid profile consists of phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, one unknown phospholipid, one unknown aminolipid, one unknown aminophospholipid and four unidentified lipids. The predominant respiratory quinone is ubiquinone-10 (Q-10). The polyphasic characterization indicated that strain KSK16Y-1T represents a novel Jiella species. The name Jiella mangrovi sp. nov., type strain KSK16Y-1T (= CGMCC 1.18745T = JCM 34332T) is proposed.


Asunto(s)
Rhizophoraceae , Alphaproteobacteria , Técnicas de Tipificación Bacteriana , China , ADN Bacteriano/genética , Ácidos Grasos/análisis , Fosfolípidos/análisis , Filogenia , Hojas de la Planta , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
19.
Sensors (Basel) ; 21(17)2021 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-34502657

RESUMEN

For urban traffic, traffic accidents are the most direct and serious risk to people's lives, and rapid recognition and warning of traffic accidents is an important remedy to reduce their harmful effects. However, research scholars are often confronted with the problem of scarce and difficult-to-collect accident data resources for traffic accident scenarios. Therefore, in this paper, a traffic data generation model based on Generative Adversarial Networks (GAN) is developed. To make GAN applicable to non-graphical data, we improve the generator network structure of the model and used the generated model to resample the original data to obtain new traffic accident data. By constructing an adversarial neural network model, we generate a large number of data samples that are similar to the original traffic accident data. Results of the statistical test indicate that the generated samples are not significantly different from the original data. Furthermore, the experiments of traffic accident recognition with several representative classifiers demonstrate that the augmented data can effectively enhance the performance of accident recognition, with a maximum increase in accuracy of 3.05% and a maximum decrease in the false positive rate of 2.95%. Experimental results verify that the proposed method can provide reliable mass data support for the recognition of traffic accidents and road traffic safety.


Asunto(s)
Accidentes de Tránsito , Redes Neurales de la Computación , Humanos , Proyectos de Investigación
20.
Org Biomol Chem ; 18(7): 1369-1376, 2020 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-31996878

RESUMEN

This paper discloses a transition metal-free selective C-H dithiocarbamation of drug skeletons using disulfiram (DSF) in the presence of KI/K2S2O8 in DMF/H2O. Drug skeletons, including 5-aminopyrazoles, indoles, pyrroloquinoline, and Julolidine, underwent C-H dithiocarbamation smoothly to afford a variety of drug-like molecules in moderate to good yields. It was found that the in situ formed 5-aminopyrazole iodide is the key intermediate for the dithiocarbamation. Bioassay results show that some of these N-heterocyclic dithiocarbamate derivatives exhibit good antifungal activity against Colletotrichum gloeosprioides and Fusarium oxysporum, F. proliferatum, Fusarium solani, Geotrichum candidum, Penicillium digitatum, Penicillium italicum, Phyricularia grisea.


Asunto(s)
Antifúngicos/farmacología , Colletotrichum/efectos de los fármacos , Fusarium/efectos de los fármacos , Geotrichum/efectos de los fármacos , Penicillium/efectos de los fármacos , Tiocarbamatos/farmacología , Antifúngicos/síntesis química , Antifúngicos/química , Derivados del Benceno/química , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Estereoisomerismo , Tiocarbamatos/síntesis química , Tiocarbamatos/química
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