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1.
Langmuir ; 40(29): 15031-15037, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-38988010

RESUMO

Currently, platinum (Pt)/carbon support composite materials have tremendous application prospects in the hydrogen evolution reaction (HER). However, one of the primary challenges for boosting their performance is designing a substrate with the desired microstructure. Herein, the intact hollow carbon spheres (HCSs) were prepared via template method. Based on the morphology variation of the as-prepared HCSs-x, we conjectured that the polydopamine (PDA) core was generated first and then slowly grew into a complete overburden (SiO2@PDA). Afterward, Pt atomic clusters were anchored on the outer shells of HCSs-4 to construct composite electrocatalysts (Pty/HCSs-4) by a chemical reduction method. Due to the low charge-transfer resistance, the HCSs have a large electrochemical surface area and provide a continuous electron transport pathway, boosting the atom utilization efficiency during hydrogen production and release. The synthesized Pt2.5/HCSs-4 electrocatalysts exhibit excellent HER activity in acidic media, which can be ascribed to the compositional modulation and delicate structural design. Specifically, when the overpotential is 10 A g-1, the overpotential can achieve 92 mV. This work opens a new route to fabricate Pt-based electrocatalysts and brings a new understanding of the formation mechanism of HCSs.

2.
Phys Chem Chem Phys ; 26(5): 4702-4715, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38251937

RESUMO

To identify superalkali-alkaline earthide ion pairs, it's theoretically shown that, as a novel class of excess electron superalkali compounds, both chair and boat forms of (AM-HMHC)-AM' (AM = Li, Na, and K; AM' = Be, Mg, and Ca; HMHC = 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16-hexaazacyclooctadecane) are good candidates. An attractive superalkali-alkaline earthide ion pair in δ+(AM-HMHC)-AM'δ- is firstly exhibited, which possesses alkaline-earthide characteristics and nonlinear optical response superior to similar M+(calix[4]pyrrole)M'- (M = Li, Na, and K; M' = Be, Mg, and Ca) with high stability. The electronic and vibrational second order hyperpolarizabilities and the frequency-dependent first hyperpolarizabilities of δ+(AM-HMHC)-AM'δ- are presented. For each pair of (AM-HMHC)-AM', the boat conformation is preferred to its chair one in the case of Hyper-Rayleigh scattering response (ßHRS). These alkaline earthides suggest prominently high ßHRS up to 2.59 × 104 a.u. (boat forms of δ+(Na-HMHC)-Caδ-). We expect that this work will inspire the preparation and characterization of these new alkaline earthides as high-performance NLO materials.

3.
Eur Arch Otorhinolaryngol ; 281(5): 2275-2280, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38085307

RESUMO

OBJECTIVES: To investigate the incidence and characteristics of adult otitis media with effusion (OME) before, during, and after the COVID-19 pandemic. METHODS: A retrospective descriptive study was conducted. The incidence, age, sex, affected ear side, time of OME onset according to COVID-19 and days of improvement after conservative treatment were determined to assess the clinical features of adult OME in different periods of the COVID-19 pandemic. RESULTS: The incidence of adult OME during these periods was 3.17%, 2.30%, 6.18%, and 3.68%, respectively. Unilateral ear involvement and male sex were more common. The onset of adult OME occurred 7.80 ± 3.97 days after COVID-19 diagnosis, and improvement was observed after 12.24 ± 5.08 days of conservative treatment. Patients in the post-pandemic period were older than those in the non-pandemic period. CONCLUSION: The incidence of adult OME in China showed a tendency to decrease, recover, and decrease again following the COVID-19 outbreak. Pandemic prevention and control measures have had a certain impact on reducing the incidence, but the elderly are more prone to this disease.


Assuntos
COVID-19 , Otite Média com Derrame , Adulto , Humanos , Masculino , Idoso , Recém-Nascido , Otite Média com Derrame/cirurgia , Pandemias , Estudos Retrospectivos , Incidência , Teste para COVID-19 , COVID-19/epidemiologia
4.
Angew Chem Int Ed Engl ; : e202407791, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38860734

RESUMO

Light-driven photoredox catalysis presents a promising approach for the activation and conversion of methane (CH4) into high value-added chemicals under ambient conditions. However, the high C-H bond dissociation energy of CH4 and the absence of well-defined C-H activation sites on catalysts significantly limit the highly efficient conversion of CH4 toward multicarbon (C2+) hydrocarbons, particularly ethylene (C2H4). Herein, we demonstrate a bimetallic design of Ag nanoparticles (NPs) and Pd single atoms (SAs) on ZnO for the cascade conversion of CH4 into C2H4 with the highest production rate compared with previous works. Mechanistic studies reveal that the synergistic effect of Ag NPs and Pd SAs, upon effecting key bond-breaking and -forming events, lowers the overall energy barrier of the activation process of both CH4 and the resulting C2H6, constituting a truly synergistic catalytic system to facilitate the C2H4 generation. This work offers a novel perspective on the advancement of photocatalytic directional CH4 conversion toward high value-added C2+ hydrocarbons through the subtle design of bimetallic cascade catalyst strategy.

5.
Microb Pathog ; 180: 106111, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37084823

RESUMO

Cutibacterium acnes (C. acnes) is a symbiotic bacterium that plays an important role in the formation of acn e inflammatory lesions. As a common component of the acne microbiome, C. acnes phages have the potential to make a significant contribution to treating antibiotic-resistant strains of C. acnes. However, little is known about their genetic composition and diversity. In this study, a new lytic phage, Y3Z, infecting C. acne, was isolated and characterized. Electron microscopy analysis revealed this phage is a siphovirus. Phage Y3Z is composed of 29,160 bp with a GC content of 56.32%. The genome contains 40 open reading frames, 17 of which had assigned functions, while no virulence-related genes, antibiotic resistance genes or tRNA were identified. The one-step growth curve showed the burst size was 30 PFU (plaque-forming unit)/cell. And it exhibited tolerance over a broad range of pH and temperature ranges. Phage Y3Z could infect and lyse all C. acnes isolates tested, though the host range of PA6 was restricted to C. acnes. Based on the phylogenetic and comparative genomic analyses, Y3Z may represent a new siphovirus infecting C. acnes. Characterization of Y3Z will enrich our knowledge about the diversity of C. acnes phages and provide a potential arsenal for thetreatment of acne infection.


Assuntos
Acne Vulgar , Bacteriófagos , Humanos , Genoma Viral , Filogenia , Propionibacterium acnes/genética , Acne Vulgar/genética , Acne Vulgar/microbiologia
6.
Artigo em Inglês | MEDLINE | ID: mdl-37712653

RESUMO

In the present work, the taxonomic relationship between Streptomyces griseomycini and Streptomyces griseostramineus was reevaluated by a comprehensive comparison of phenotypic, chemotaxonomic and genomic characteristics, as well as phylogeny. Phylogenetic analysis based on 16S rRNA gene sequences and whole-genome sequences indicated that Streptomyces griseostramineus JCM 4385T was clustered together with Streptomyces griseomycini JCM 4382T, suggesting they were closely related to each other. However, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between their genomes were 99.7 and 97.5 %, respectively, much larger than the recommended threshold values of 96.7 % ANI and 70 % dDDH for Streptomyces species delineation. In addition, the morphological, cultural, physio-biochemical and chemotaxonomic features of these two species further demonstrated that they belonged to the same genome species. Based on the above data and the principle of priority in nomenclature, it is proposed that S. griseostramineus (Preobrazhenskaya et al. 1957) Pridham et al. 1958 (Approved Lists 1980) is a later heterotypic synonym of S. griseomycini (Preobrazhenskaya et al. 1957) Pridham et al. 1958 (Approved Lists 1980).


Assuntos
Ácidos Graxos , Streptomyces , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Ácidos Graxos/química , Streptomyces/genética , Nucleotídeos
7.
Int J Syst Evol Microbiol ; 73(12)2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38054463

RESUMO

Two actinomycete strains, designated MG62T and CRLD-Y-1, were isolated from rhizosphere soil of Koelreuteria paniculata and healthy leaves of Xanthium sibiricum, respectively, in Hunan province, PR China. They could produce abundant aerial mycelia that generated rod-shaped spores with spiny surfaces. Morphological features of the two strains are typical of the genus Streptomyces. Strains MG62T and CRLD-Y-1 exhibited 99.93 % 16S rRNA gene sequence similarity. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between them were 99.99 and 100 %, respectively, suggesting that they belonged to the same species. 16S rRNA gene sequences analysis revealed that the two strains belonged to the genus Streptomyces and showed highest similarities to Streptomyces violarus NBRC 13104T (99.07-99.29 %) and Streptomyces arenae ISP 5293T (99.21-99.35 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains MG62T and CRLD-Y-1 were closely related to S. violarus NBRC 13104T and S. arenae ISP 5293T. However, the ANI, dDDH and multilocus sequence analysis evolutionary distance values between the two strains and their relatives provide a robust basis upon which to verify strains MG62T and CRLD-Y-1 as representing a novel species. Moreover, a comprehensive comparison of phenotypic and chemotaxonomic characteristics further confirmed that the two strains were distinct from their relatives. Based on all these data above, strains MG62T and CRLD-Y-1 should represent a novel Streptomyces species, for which the name Streptomyces koelreuteriae sp. nov. is proposed. The type strain is MG62T (=JCM 34747T=MCCC 1K06175T).


Assuntos
Streptomyces , Xanthium , Ácidos Graxos/química , Análise de Sequência de DNA , Filogenia , Rizosfera , RNA Ribossômico 16S/genética , Microbiologia do Solo , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Vitamina K 2
8.
Phys Chem Chem Phys ; 25(38): 26196-26202, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37740331

RESUMO

In recent years, bifunctional electrocatalysts, nanomaterials directly grown on the substrate for application towards the hydrogen evolution reaction (HER), have become of interest for sustainable and clean energy technologies. However, the influence of interfacial interactions between the electrode materials and substrate on device performance remains unclear and is rarely investigated. Herein, we report two-dimensional (2D) CoO nanosheets grown on carbon cloth (CC) (2D CoO/CC) to construct a hybrid electrocatalyst with a seamlessly conductive network. By a series of structure analyses, we recommend that the CoO nanosheets and CC are connected via adsorption. The 2D CoO/CC nanosheets show superior HER performance to the commercial Pt/C and CoO(aq.)/CC nanosheets, including onset potentials of 2 mV, low overpotential of 22 mV at 10 mA cm-2 and Tafel slope of 37 mV dec-1. The results of density functional theory (DFT) calculations reveal that the adsorbability plays an important role in determining the performance of the electrocatalysts for the HER. This work provides a new insight into the interfacial interactions between the electrode material and the substrate in electrochemical devices, and paves the way for the rational design and construction of high-performance electrochemical devices for practical energy applications.

9.
J Nanobiotechnology ; 21(1): 59, 2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36810074

RESUMO

Chemodynamic therapy of cancer is limited by insufficient endogenous H2O2 generation and acidity in the tumor microenvironment (TME). Herein, we developed a biodegradable theranostic platform (pLMOFePt-TGO) involving composite of dendritic organosilica and FePt alloy, loaded with tamoxifen (TAM) and glucose oxidase (GOx), and encapsulated by platelet-derived growth factor-B (PDGFB)-labeled liposomes, that effectively uses the synergy among chemotherapy, enhanced chemodynamic therapy (CDT), and anti-angiogenesis. The increased concentration of glutathione (GSH) present in the cancer cells induces the disintegration of pLMOFePt-TGO, releasing FePt, GOx, and TAM. The synergistic action of GOx and TAM significantly enhanced the acidity and H2O2 level in the TME by aerobiotic glucose consumption and hypoxic glycolysis pathways, respectively. The combined effect of GSH depletion, acidity enhancement, and H2O2 supplementation dramatically promotes the Fenton-catalytic behavior of FePt alloys, which, in combination with tumor starvation caused by GOx and TAM-mediated chemotherapy, significantly increases the anticancer efficacy of this treatment. In addition, T2-shortening caused by FePt alloys released in TME significantly enhances contrast in the MRI signal of tumor, enabling a more accurate diagnosis. Results of in vitro and in vivo experiments suggest that pLMOFePt-TGO can effectively suppress tumor growth and angiogenesis, thus providing an exciting potential strategy for developing satisfactory tumor theranostics.


Assuntos
Ferroptose , Neoplasias , Humanos , Linhagem Celular Tumoral , Microambiente Tumoral , Peróxido de Hidrogênio/metabolismo , Neoplasias/tratamento farmacológico , Apoptose , Glucose Oxidase/metabolismo
10.
J Basic Microbiol ; 63(5): 530-541, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37032321

RESUMO

Salmonella enterica contamination is a primary cause of global food poisoning. Using phages as bactericidal alternatives to antibiotics could confront the issue of drug resistance. However, the problem of phage resistance, especially mutant strains with multiple phage resistance, is a critical barrier to the practical application of phages. In this study, a library of EZ-Tn5 transposable mutants of susceptible host S. enterica B3-6 was constructed. After the infestation pressure of a broad-spectrum phage TP1, a mutant strain with resistance to eight phages was obtained. Analysis of the genome resequencing results revealed that the SefR gene was disrupted in the mutant strain. The mutant strain displayed a reduced adsorption rate of 42% and a significant decrease in swimming and swarming motility, as well as a significantly reduced expression of the flagellar-related FliL and FliO genes to 17% and 36%, respectively. An uninterrupted form of the SefR gene was cloned into vector pET-21a (+) and used for complementation of the mutant strain. The complemented mutant exhibited similar adsorption and motility as the wild-type control. These results suggest that the disrupted flagellar-mediated SefR gene causes an adsorption inhibition, which is responsible for the phage-resistant phenotype of the S. enterica transposition mutant.


Assuntos
Bacteriófagos , Salmonella enterica , Mutação Silenciosa , Mutação , Antibacterianos/farmacologia
11.
Angew Chem Int Ed Engl ; 62(29): e202304306, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37208951

RESUMO

Benzimidazoles are a versatile class of scaffolds with important biological activities, whereas their synthesis in a lower-cost and more efficient manner remains a challenge. Here, we demonstrate a conceptually new radical route for the high-performance photoredox coupling of alcohols and diamines to synthesize benzimidazoles along with stoichiometric hydrogen (H2 ) over Pd-decorated ultrathin ZnO nanosheets (Pd/ZnO NSs). The mechanistic study reveals the unique advantage of ZnO NSs over other supports and particularly that the features of Pd nanoparticles in facilitating the cleavage of the α-C-H bond of alcohols and adsorbing subsequently-generated C-centered radicals hold the key to turning on the reaction. This work highlights a new insight into radical-induced efficient benzimidazole synthesis pairing with H2 evolution by rationally designing semiconductor-based photoredox systems.

12.
Phys Chem Chem Phys ; 24(9): 5690-5699, 2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35187550

RESUMO

To combine both electride and alkalide characteristics in one molecular switch, it is shown herein that the phenalenyl radical and the M3 ring (M3-PHY, M = Li, Na, and K) stacked with parallel and vertical geometries are good candidates. The former geometry is the superalkali electride e-⋯M3+-PHY while the latter geometry is the superalkalide Mδ--M2(1-δ)+-PHY-. The superalkalide Mδ--M2(1-δ)+-PHY- may isomerize to the superalkali electride e-⋯M3+-PHY (M = Li, Na, and K) using suitable long-wavelength irradiation, while the latter may isomerize to the former with suitable short-wavelength irradiation. Also, applying suitable oriented external electric fields can drive the superalkalide Mδ-M2(1-δ)+-PHY- to change into the superalkali electride e-⋯M3+-PHY (M = Li, Na, and K). The differences in the static and dynamic first hyperpolarizability (ß0) values between them were also studied.

13.
Environ Res ; 212(Pt D): 113391, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35597293

RESUMO

Taihu Lake is the most important drinking water source of the major cities in the Yangtze River Delta. The pollution of endocrine disruptors (EDCs)in Taihu Lake has been increasing recently, the accurate determination is an important guide for predicting its health risks and developing appropriate controls. Monitoring organic pollutants in water using the diffusive gradient in thin film technique (DGT) has attracted much attention due to more accuracy and convenience than the grab sampling methods. In this study, a novel cyclodextrin polymer (CDP) synthesized by the simple and green method in water was taken as an adsorbent for the binding gel. Four endocrine-disrupting chemicals (EDCs), bisphenol A (BPA), 17α-ethinylestradiol (EE2), 17ß-estradiol (E2), and estriol (E3), were taken as models to determine the diffusion coefficients (4.68 × 10-6, 3.38 × 10-6, 3.34 × 10-6 and 4.31 × 10-6 cm2/s) and to test the performance of DGT, such as adsorption capacity and deployment time (1-5 day). The assembled CDP-DGT was adopted to determine four EDCs in a simulated water environment (3-9 of pH, 0.001-0.5 M of ionic strength (IS), and dissolved organic matter (DOM) of 0-20 mg/L). The ability of CDP-DGT sampling was verified in the Jiuxiang River and was carried out for a large-scale field application of in situ sampling EDCs in Taihu Lake basin. The results show that the total EDCs concentration range and the estradiol equivalent concentrations (EEQ) in Taihu Lake and its main rivers are 2.78 ng/L to 11.08 ng/L and 2.62 ng/L to 10.91 ng/L, respectively. The risk quotients (RQs) of all sampling sites in the region were greater than 1, indicating that EDCs pose a serious threat to aquatic organisms in the area. Therefore, the monitoring of EDCs in the Taihu Lake basin should be further strengthened.


Assuntos
Disruptores Endócrinos , Poluentes Químicos da Água , Celulose , China , Ciclodextrinas , Disruptores Endócrinos/análise , Monitoramento Ambiental/métodos , Estradiol , Géis , Lagos/química , Medição de Risco , Rios/química , Água , Poluentes Químicos da Água/análise
14.
J Nanobiotechnology ; 20(1): 264, 2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35672821

RESUMO

The application of chemodynamic therapy (CDT) for cancer is a serious challenge owing to the low efficiency of the Fenton catalyst and insufficient H2O2 expression in cells. Herein, we fabricated a PDGFB targeting, biodegradable FePt alloy assembly for magnetic resonance imaging (MRI)-guided chemotherapy and starving-enhanced chemodynamic therapy for cancer using PDGFB targeting, pH-sensitive liposome-coated FePt alloys, and GOx (pLFePt-GOx). We found that the Fenton-catalytic activity of FePt alloys was far stronger than that of traditional ultrasmall iron oxide nanoparticle (UION). Upon entry into cancer cells, pLFePt-GOx nanoliposomes degraded into many tiny FePt alloys and released GOx owing to the weakly acidic nature of the tumor microenvironment (TME). The released GOx-mediated glucose consumption not only caused a starvation status but also increased the level of cellular H2O2 and acidity, promoting Fenton reaction by FePt alloys and resulting in an increase in reactive oxygen species (ROS) accumulation in cells, which ultimately realized starving-enhanced chemodynamic process for killing tumor cells. The anticancer mechanism of pLFePt-GOx involved ROS-mediated apoptosis and ferroptosis, and glucose depletion-mediated starvation death. In the in vivo assay, the systemic delivery of pLFePt-GOx showed excellent antitumor activity with low biological toxicity and significantly enhanced T2-weighted magnetic resonance imaging (MRI) signal of the tumor, indicating that pLFePt-GOx can serve as a highly efficient theranostic tool for cancer. This work thus describes an effective, novel multi-modal cancer theranostic system.


Assuntos
Nanopartículas , Neoplasias , Ligas , Linhagem Celular Tumoral , Glucose , Humanos , Peróxido de Hidrogênio/metabolismo , Imageamento por Ressonância Magnética , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Proteínas Proto-Oncogênicas c-sis/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Microambiente Tumoral
15.
Curr Microbiol ; 80(1): 27, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36473940

RESUMO

A novel actinobacterium, designated strain CRSS-Y-16T, was isolated from the healthy leaves of Xanthium sibiricum, in China and characterized by a polyphasic approach. This strain produced abundant aerial mycelia that generated rod-shaped spores with spiny surfaces. The cell wall contained LL-diaminopimelic acid. The major cellular fatty acids (>10.0%) were C16:0, iso-C16:0, and C18:1 ω9c. The predominant menaquinones were MK-9(H2) and MK-9(H4). The detected polar lipids were diphosphatidylglycerol, hydroxyl phosphatidylethanolamine, phosphatidylethanolamine, phosphatidylinositolmannoside, phospholipids of unknown structure containing glucosamine and unidentified phospholipids. The genomic G+C content was 70.7%. The full-length 16S rRNA gene sequence analysis indicated that strain CRSS-Y-16T belonged to the genus Streptomyces and shared <98.7% sequence similarities with all recognized type species of the genus. Phylogenetic analysis based on 16S rRNA gene sequences showed that this strain formed a distinct branch. Phylogenomic analysis demonstrated that it was closely related to Streptomyces panaciradicis 1MR-8T. However, the clustering patterns resulting from phylogenomic tree verified that strain CRSS-Y-16T represented a novel Streptomyces species. This result was further confirmed by low average nucleotide identity and digital DNA-DNA hybridization values (87.54% and 30.1%) between them. Based on all these data, it is concluded that strain CRSS-Y-16T represents a novel Streptomyces species, for which the name Streptomyces spinosirectus sp. nov. is proposed. The type strain is CRSS-Y-16T (=MCCC 1K06950T=JCM 35007T).


Assuntos
Plantas Medicinais , Streptomyces , Xanthium , Filogenia , RNA Ribossômico 16S/genética , Streptomyces/genética , DNA
16.
Artigo em Inglês | MEDLINE | ID: mdl-34410901

RESUMO

Two strains of Actinobacteria, designated CRXT-Y-14T and CRXT-G-22T, were isolated from the healthy leaves and seeds, respectively, of a medicinal plant Xanthium sibiricum. Their taxonomic positions were determined using a polyphasic approach. Strain CRXT-Y-14T produced flexuous chains of smooth-surfaced spores. Strain CRXT-G-22T produced straight chains of smooth-surfaced spores. Their morphological features were consistent with the diagnostic characteristics of members of the genus Streptomyces. The results of 16S rRNA gene sequence analyses indicated two strains represented members of the genus Streptomyces. CRXT-Y-14T shared 99.3, 98.9, 98.8 % sequence similarities to Streptomyces atriruber NRRL B-24165T, Streptomyces avermitilis MA-4680T and Streptomyces davaonensis JCM 4913T, respectively. Whilst CRXT-G-22T exhibited highest similarity to Streptomyces acidiscabies ATCC 49003T (98.9 %). The results of phylogenetic analyses based on 16S rRNA gene sequences indicated that the closest phylogenetic neighbours of strains CRXT-Y-14T and CRXT-G-22T were S. atriruber NRRL B-24165T and S. acidiscabies ATCC 49003T, respectively. The phylogenomic analyses further confirmed the relative relationship between strain CRXT-G-22T and S. acidiscabies ATCC 49003T, but indicated that CRXT-Y-14T could represent a novel species of the genus Streptomyce. However, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between CRXT-Y-14T and strain CRXT-G-22T, between CRXT-Y-14T and S. atriruber NRRL B-24165T, and between CRXT-G-22T and S. acidiscabies ATCC 49003T were 85.4 and 23.2 %, 85.8 and 23.9 % and 89.1 and 34.1 %, respectively, far below the 95~96 and 70 % cut-off points recommended for delineating species. Furthermore, these two novel isolates were distinctly differentiated from their relatives in the genus Streptomyces with respect to phenotypic and chemotaxonomic characteristics. On the basis of these data, CRXT-Y-14T and CRXT-G-22T clearly represent two novel species within the genus Streptomyces, for which the names Streptomyces xanthii sp. nov. (type strain CRXT-Y-14T = MCCC 1K04966T= JCM 34527T) and Streptomyces roseirectus sp. nov. (type CRXT-G-22T = MCCC 1K04979T= JCM 34565T) are proposed.


Assuntos
Filogenia , Streptomyces , Xanthium/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Plantas Medicinais/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Streptomyces/classificação , Streptomyces/isolamento & purificação
17.
Artigo em Inglês | MEDLINE | ID: mdl-34382927

RESUMO

As two separate genomic species, Streptomyces calvus and Streptomyces aureorectus were approved in 1980 and 1986, respectively. However, recently, it has been found that the average nucleotide identity and digital DNA-DNA hybridization values between S. calvus JCM 4326T and S. aureorectus DSM 41692T were 99.19 and 92.70 %, respectively, much higher than 95-96 and 70  % cut-off points proposed and the generally accepted species boundaries. These data indicated that they should be classified as the same genomic species. Furthermore, this result was also supported by a comprehensive comparison of phenotypic, chemotaxonomic and physio-biochemical characteristics between the two type strains. All these data indicated that S. calvus and S. aureorectus had the same taxonomic position. In accordance with the principle of priority, it is proposed that S. aureorectus is a later heterotypic synonyms of S. calvus.


Assuntos
Filogenia , Streptomyces/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
18.
Artigo em Inglês | MEDLINE | ID: mdl-34382928

RESUMO

A novel genistein-producing actinobacterial strain, designated strain CRPJ-33T, was isolated from the healthy leaves of a medicinal plant Xanthium sibiricum collected from Hunan Province, PR China. 16S rRNA gene sequence analysis indicated strain CRPJ-33T belonged to the genus Streptomyces and had 99.7, 99.0, 98.9, 98.9, 98.8 and 98.7% sequence similarities to Streptomyces zhihengii YIM T102T, Streptomyces eurocidicus NRRL B-1676T, Streptomyces xanthochromogenes NRRL B-5410T, Streptomyces michiganensis NBRC 12797T, Streptomyces mauvecolor LMG 20100T and Streptomyces lavendofoliae NBRC 12882T, respectively. Phylogenetic analysis of 16S rRNA gene sequences showed that strain CRPJ-33T was most closely related to S. zhihengii YIM T102T. However, digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between them were much less than the recommended threshold values. Furthermore, differential comparisons of the phenotypic characteristics were enough to distinguish strain CRPJ-33T from S. zhihengii YIM T102T. Meanwhile, the ANI and dDDH values or MLSA distances between strain CRPJ-33T and other type strains, which exhibited ≥98.7 % 16S rRNA gene sequence similarities to strain CRPJ-33T, were far away from the recommended threshold values. Based on these results, it is thought that strain CRPJ-33T should represent a novel species of the genus Streptomyces, for which the name Streptomyces genisteinicus sp. nov. is proposed. The type strain is CRPJ-33T (=MCCC 1K04965T=JCM 34526T). In addition, the phenotypic, chemotaxonomic and genotypic characteristics, as well as phylogenetic information revealed that the type strains of S. xanthochromogenes and S. michiganensis should belong to same genomic species. Consequently, it is proposed that S. michiganensis is a heterotypic synonym of S. xanthochromogenes for which an emended description is given.


Assuntos
Genisteína/metabolismo , Filogenia , Streptomyces , Xanthium/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Folhas de Planta/microbiologia , Plantas Medicinais/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Streptomyces/classificação , Streptomyces/isolamento & purificação
19.
Org Biomol Chem ; 19(46): 10047-10067, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34751696

RESUMO

Triptycene derivatives, a type of specific aromatic compound, have been attracting much attention in many research areas. Over the past several years, triptycene and its derivatives have been described to be useful and efficient building blocks for the design and synthesis of novel supramolecular acceptors, porous materials and luminescent materials with specific structures and properties. In this review, recent researches on triptycene derivatives in supramolecular and materials chemistry are summarized. Especially, the construction of a new type of macrocyclic arenes and organic cages with triptycene and its derivatives as building blocks are focused on, and their applications in molecular recognition, self-assembly and gas selective sorption are highlighted. Moreover, the applications of triptycene and its derivatives in porous organic materials and thermally activated delayed fluorescence (TADF) materials are also discussed.

20.
Transpl Infect Dis ; 23(1): e13403, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32638491

RESUMO

Human herpesvirus 6B (HHV-6B) encephalitis in a liver transplant recipient is rarely reported. In this report, we presented a case of HHV-6B encephalitis in a liver transplant recipient and reviewed the relevant literature. A 56-year-old man was admitted to the intensive care unit (ICU) with an acute headache and intermittent convulsion 17 days after liver transplantation. Next-generation sequencing (NGS) of the cerebrospinal fluid (CSF) revealed 30691 sequence reads of HHV-6B and real-time polymerase chain reaction (real-time PCR) of the CSF detected HHV-6B DNA at 12 000 copies/mL, so the patient was diagnosed with HHV-6B encephalitis and received ganciclovir treatment promptly. The condition of the patient improved well and returned to the general ward with no neurologic deficits. This case indicated that adequate awareness, early diagnosis, and timely treatment are crucial to a good prognosis of HHV-6B encephalitis after liver transplantation.


Assuntos
Encefalite Viral , Herpesvirus Humano 6 , Transplante de Fígado , Infecções por Roseolovirus , DNA Viral , Herpesvirus Humano 6/genética , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia
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