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1.
J Am Chem Soc ; 146(3): 1926-1934, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38193748

RESUMEN

Dielectric capacitors are highly desired in modern electronic devices and power systems to store and recycle electric energy. However, achieving simultaneous high energy density and efficiency remains a challenge. Here, guided by theoretical and phase-field simulations, we are able to achieve a superior comprehensive property of ultrahigh efficiency of 90-94% and high energy density of 85-90 J cm-3 remarkably in strontium titanate (SrTiO3), a linear dielectric of a simple chemical composition, by manipulating local symmetry breaking through introducing Ti/O defects. Atomic-scale characterizations confirm that these Ti/O defects lead to local symmetry breaking and local lattice strains, thus leading to the formation of the isolated ultrafine polar nanoclusters with varying sizes from 2 to 8 nm. These nanoclusters account for both considerable dielectric polarization and negligible polarization hysteresis. The present study opens a new realm of designing high-performance dielectric capacitors utilizing a large family of readily available linear dielectrics with very simple chemistry.

2.
J Am Chem Soc ; 146(29): 20205-20212, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39007348

RESUMEN

Incipient ferroelectrics have emerged as an attractive class of functional materials owing to their potential to be engineered for exotic ferroelectric behavior, holding great promise for expanding the ferroelectric family. However, thus far, their artificially engineered ferroelectricity has fallen far short of rivaling classic ferroelectrics. In this study, we address this challenge by developing a superfine nanodomain engineering strategy. By applying this approach to representative incipient ferroelectric of SrTiO3-based films, we achieve unprecedentedly strong ferroelectricity, not only surpassing previous records for incipient ferroelectrics but also being comparable to classic ferroelectrics. The remanent polarization of the thin film reaches up to 17.0 µC cm-2 with an ultrahigh Curie temperature of 973 K. Atomic-scale investigations elucidate the origin of this robust ferroelectricity in the emergent high-density superfine nanodomains spanning merely 3-10 unit cells. Combining experimental results with theoretical assessments, we unveil the underlying mechanism, where the intentionally introduced diluted foreign Fe element creates a deeper Landau energy well and promotes a short-range ordering of polarization. Our developed strategy significantly streamlines the design of unconventional ferroelectrics, providing a versatile pathway for exploring new and superior ferroelectric materials.

3.
Small ; 20(7): e2306486, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37803415

RESUMEN

Lead-free antiferroelectrics with excellent energy storage performance can become the core components of the next-generation advanced pulse power capacitors. However, the low energy storage efficiency caused by the hysteresis of antiferroelectric-ferroelectric transition largely limits their development toward miniaturization, lightweight, and integration. In this work, an ultrahigh recoverable energy storage density of ≈11.4 J cm-3 with a high efficiency of ≈80% can be realized in La-modified Ag0.5 Na0.5 NbO3 antiferroelectric ceramics at an ultrahigh breakdown electric field of ≈67 kV mm-1 by the compromise optimization between antiferroelectricity enhancement and nanodomain engineering, resulting in the transformation of large-size ferrielectric antipolar stripe domains into ultrasmall antiferroelectric nanodomains or polarization nanoregions revealing as Moiré fringe structures. In addition, the enhanced transparency with increasing La content can also be clearly observed. This work not only develops new lead-free antiferroelectric energy storage materials with high application potential but also demonstrates that the strategy of compromise optimization between antiferroelectricity modulation and nanodomain engineering is an effective avenue to enhance the energy storage performance of antiferroelectrics.

4.
Small ; 20(36): e2400997, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38712477

RESUMEN

Dielectric capacitors are widely used in advanced electrical and electronic systems due to the rapid charge/discharge rates and high power density. High comprehensive energy storage properties are the ultimate ambition in the field of application achievements. Here, the high-entropy strategy is proposed to design and fabricate single-phase homogeneous (Bi0.5Ba0.1Sr0.1Ca0.2Na0.1)(Fe0.5Ti0.3Zr0.1Nb0.1)O3 ceramic, the hierarchical heterostructure including rhombohedral-tetragonal multiphase nanoclusters and locally disordered oxygen octahedral tilt can lead to the increased dielectric relaxation, diffused phase transition, diverse local polarization configurations, grain refinement, ultrasmall polar nanoregions, large random field, delayed polarization saturation and improved breakdown field. Accordingly, a giant Wrec ≈13.3 J cm-3 and a high η ≈78% at 66.4 kV mm-1 can be simultaneously achieved in the lead-free high-entropy BiFeO3-based ceramic, showing an obvious advantage in overall energy-storage properties over BiFeO3-based lead-free ceramics. Moreover, an ultrafast discharge rate (t0.9 = 18 ns) can be achieved at room temperature, concomitant with favorable temperature stability in the range of 20-160 °C, due to the enhanced diffuse phase transition and fast polarization response. This work provides a feasible pathway to design and generate dielectric materials exhibiting high comprehensive energy-storage performance.

5.
Small ; 20(37): e2401229, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38733235

RESUMEN

The great potential of K1/2Bi1/2TiO3 (KBT) for dielectric energy storage ceramics is impeded by its low dielectric breakdown strength, thereby limiting its utilization of high polarization. This study develops a novel composition, 0.83KBT-0.095Na1/2Bi1/2ZrO3-0.075 Bi0.85Nd0.15FeO3 (KNBNTF) ceramics, demonstrating outstanding energy storage performance under high electric fields up to 425 kV cm-1: a remarkable recoverable energy density of 7.03 J cm-3, and a high efficiency of 86.0%. The analysis reveals that the superior dielectric breakdown resistance arises from effective mitigation of space charge accumulation at the interface, influenced by differential dielectric and conductance behaviors between grains and grain boundaries. Electric impedance spectra confirm the significant suppression of space charge accumulation in KNBNTF, attributable to the co-introduction of Na1/2Bi1/2ZrO3 and Bi0.85Nd0.15FeO3. Phase-field simulations reveal the emergence of a trans-granular breakdown mode in KNBNTF resulting from the mitigated interfacial polarization, impeding breakdown propagation and increasing dielectric breakdown resistance. Furthermore, KNBNTF exhibits a complex local polarization and enhances the relaxor features, facilitating high field-induced polarization and establishing favorable conditions for exceptional energy storage performance. Therefore, the proposed strategy is a promising design pathway for tailoring dielectric ceramics in energy storage applications.

6.
Arch Microbiol ; 206(6): 279, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38805051

RESUMEN

Yeast, which plays a pivotal role in the brewing, food, and medical industries, exhibits a close relationship with human beings. In this study, we isolated and purified 60 yeast strains from the natural fermentation broth of Sidamo coffee beans to screen for indigenous beneficial yeasts. Among them, 25 strains were obtained through morphological characterization on nutritional agar medium from Wallerstein Laboratory (WL), with molecular biology identifying Saccharomyces cerevisiae strain YBB-47 and the remaining 24 yeast strains identified as Pichia kudriavzevii. We investigated the fermentation performance, alcohol tolerance, SO2 tolerance, pH tolerance, sugar tolerance, temperature tolerance, ester production capacity, ethanol production capacity, H2S production capacity, and other brewing characteristics of YBB-33 and YBB-47. The results demonstrated that both strains could tolerate up to 3% alcohol by volume at a high sucrose mass concentration (400 g/L) under elevated temperature conditions (40 ℃), while also exhibiting a remarkable ability to withstand an SO2 mass concentration of 300 g/L at pH 3.2. Moreover, S. cerevisiae YBB-47 displayed a rapid gas production rate and strong ethanol productivity. whereas P. kudriavzevii YBB-33 exhibited excellent alcohol tolerance. Furthermore, this systematic classification and characterization of coffee bean yeast strains from the Sidamo region can potentially uncover additional yeasts that offer high-quality resources for industrial-scale coffee bean production.


Asunto(s)
Etanol , Fermentación , Pichia , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/aislamiento & purificación , Pichia/metabolismo , Pichia/aislamiento & purificación , Pichia/genética , Pichia/clasificación , Etanol/metabolismo , Concentración de Iones de Hidrógeno , Café/microbiología , Coffea/microbiología , Temperatura , Semillas/microbiología , Sulfuro de Hidrógeno/metabolismo
7.
Nano Lett ; 23(3): 948-953, 2023 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-36716221

RESUMEN

Electric-field-induced antiferroelectric-ferroelectric (AFE-FE) phase transition is a prominent feature of antiferroelectric (AFE) materials. The critical electric field of this phase transition is crucial for the device performance of AEFs in many applications, but the determining factor of the critical electric field is still unclear. Here, we have established the correlation between the underlying structure and the critical electric field by using in situ synchrotron X-ray diffraction and high-resolution neutron diffraction in Pb(Zr,Sn,Ti)O3-based antiferroelectrics. It is found that the critical electric field is determined by the angle between the average polarization vector in the incommensurate AFE state and the [111]P polarization direction in the rhombohedral FE state. A large polarization rotation angle gives rise to a large critical electric field. Further, density functional theory (DFT) calculations corroborate that the lower energy is required for driving a smaller angle polarization rotation. Our discovery will offer guidance to optimize the performance of AFE materials.

8.
J Am Chem Soc ; 145(11): 6194-6202, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36892264

RESUMEN

Chemical design of lead-free relaxors with simultaneously high energy density (Wrec) and high efficiency (η) for capacitive energy-storage has been a big challenge for advanced electronic systems. The current situation indicates that realizing such superior energy-storage properties requires highly complex chemical components. Herein, we demonstrate that, via local structure design, an ultrahigh Wrec of 10.1 J/cm3, concurrent with a high η of 90%, as well as excellent thermal and frequency stabilities can be achieved in a relaxor with a very simple chemical composition. By introducing 6s2 lone pair stereochemical active Bi into the classical BaTiO3 ferroelectric to generate a mismatch between A- and B-site polar displacements, a relaxor state with strong local polar fluctuations can be formed. Through advanced atomic-resolution displacement mapping and 3D reconstructing the nanoscale structure from neutron/X-ray total scattering, it is revealed that the localized Bi enhances the polar length largely at several perovskite unit cells and disrupts the long-range coherent Ti polar displacements, resulting in a slush-like structure with extremely small size polar clusters and strong local polar fluctuations. This favorable relaxor state exhibits substantially enhanced polarization, and minimized hysteresis at a high breakdown strength. This work offers a feasible avenue to chemically design new relaxors with a simple composition for high-performance capacitive energy-storage.

9.
J Am Chem Soc ; 145(35): 19396-19404, 2023 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-37606548

RESUMEN

Designing Pb-free relaxors with both a high capacitive energy density (Wrec) and high storage efficiency (η) remains a remarkable challenge for cutting-edge pulsed power technologies. Local compositional heterogeneity is crucial for achieving complex polar structure in solid solution relaxors, but its role in optimizing energy storage properties is often overlooked. Here, we report that an exceptionally high Wrec of 15.2 J cm-3 along with an ultrahigh η of 91% can be achieved through designing local chemical clustering in Bi0.5Na0.5TiO3-BaTiO3-based relaxors. A three-dimensional atomistic model derived from neutron/X-ray total scattering combined with reverse Monte Carlo method reveals the presence of subnanometer scale clustering of Bi, Na, and Ba, which host differentiated polar displacements, and confirming the prediction by density functional theory calculations. This leads to a polar state with small polar clusters and strong length and direction fluctuations in unit-cell polar vectors, thus manifesting improved high-field polarizability, steadily reduced hysteresis, and high breakdown strength macroscopically. The favorable polar structure features also result in a unique field-increased η, excellent stability, and superior discharge capacity. Our work demonstrates that the hidden local chemical order exerts a significant impact on the polarization characteristic of relaxors, and can be exploited for accessing superior energy storage performance.

10.
J Am Chem Soc ; 145(21): 11764-11772, 2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37205832

RESUMEN

Dielectric capacitors have captured substantial attention for advanced electrical and electronic systems. Developing dielectrics with high energy density and high storage efficiency is challenging owing to the high compositional diversity and the lack of general guidelines. Herein, we propose a map that captures the structural distortion (δ) and tolerance factor (t) of perovskites to design Pb-free relaxors with extremely high capacitive energy storage. Our map shows how to select ferroelectric with large δ and paraelectric components to form relaxors with a t value close to 1 and thus obtaining eliminated hysteresis and large polarization under a high electric breakdown. Taking the Bi0.5Na0.5TiO3-based solid solution as an example, we demonstrate that composition-driven predominant order-disorder characteristic of local atomic polar displacements endows the relaxor with a slushlike structure and strong local polar fluctuations at several nanoscale. This leads to a giant recoverable energy density of 13.6 J cm-3, along with an ultrahigh efficiency of 94%, which is far beyond the current performance boundary reported in Pb-free bulk ceramics. Our work provides a solution through rational chemical design for obtaining Pb-free relaxors with outstanding energy-storage properties.

11.
Small ; 19(47): e2303768, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37485639

RESUMEN

Lead-free dielectric ceramics with excellent energy-storage performance are crucial to the development of the next-generation advanced pulse power capacitors. However, low energy-storage density limits the evolution of capacitors toward lightweight, miniaturization, and integration. Here, an effective strategy of constructing highly dynamic polarization heterogeneous nanoregions is proposed in lead-free relaxors to realize an ultrahigh energy-storage density of ≈8.0 J cm-3 , making almost ten times the growth of energy-storage density compared with pure Bi0.5 Na0.5 TiO3 ceramic, accompanied by a higher energy efficiency of ≈80% as well as an ultrafast discharge rate of ≈20 ns. Ultrasmall polarization heterogeneous nanoregions with different orientations and ultrahigh flexibility, and significantly decreased grain size to submicron lead to reduced heat loss, improved breakdown electric field and polarization, enhanced relaxation, and delayed polarization saturation behaviors, contributing to the remarkable energy-storage performance. Moreover, the breakdown path distribution or electrical tree evolution behaviors are systematically studied to reveal the origin of ultrahigh breakdown electric field through phase field simulations. This work demonstrates that constructing highly dynamic polarization heterogeneous nanoregions is a powerful approach to develop new lead-free dielectric materials with high energy-storage performance.

12.
Phys Rev Lett ; 131(24): 246801, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-38181148

RESUMEN

Disordered ferroics hold great promise for next-generation magnetoelectric devices because their lack of symmetry constraints implies negligible hysteresis with low energy costs. However, the transition temperature and the magnitude of polarization and magnetization are still too low to meet application requirements. Here, taking the prototype perovskite of SrTiO_{3} as an instance, we realize a coexisting spin and dipole reentrant glass states in SrTiO_{3} homoepitaxial films via manipulation of local symmetry. Room-temperature saturation magnetization and spontaneous polarization reach ∼ 10 emu/cm^{3} and ∼ 25 µC/cm^{2}, respectively, with high transition temperatures (101 K and 236 K for spin and dipole glass temperatures and 556 K and 1100 K for Curie temperatures, respectively). Our atomic-scale investigation points out an underlying mechanism, where the Ti/O-defective unit cells break the local translational and orbital symmetry to drive the formation of unusual slush states. This study advances our understanding of the nature of the intricate couplings of ferroic glasses. Our approach could be applied to numerous perovskite oxides for the simultaneous control of the local magnetic and polar orderings and for the exploration of the underlying physics.

13.
Plant Dis ; 2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-38035784

RESUMEN

Styphnolobium japonicum (L.) Schott (family Fabaceae Juss.) also called pagoda tree, is widely planted in northern China in landscape plantings, for erosion control and forestry. In recent years, symptoms of branch dieback were observed on S. japonicum in the southern part of Xinjiang province, China. From 2019 to 2022, in total ca. 1000 ha area was surveyed in Korla (41.68°N, 86.06°E), Bohu (41.95°N, 86.53°E) and Alaer (41.15°N, 80.29°E). Typical symptoms were observed in 70% of the surveyed branches. To identify the cause, we collected 50 symptomatic branches. Symptoms were initially observed on green current-year twigs, which turned grayish white in color. In the later stages of disease development, a large number of nacked black conidia formed under epidermis of perennial branches, causing visible black protrusions (pycnidia) on branch surface. The disease occurred throughout the entire growing season of S. japonicum. Symptoms also occurred on the inflorescence, fruit, and twigs. In some cases, infection resulted in tree mortality. Isolations were made from the margin between healthy and diseased tissues. Small pieces were excised, surface disinfested (75% ethanol 30 s, 1% NaClO solution 5 mins), cut into pieces (5 to 10 mm2), and incubated on PDA medium at 28℃ for 3 days. A total of 16 isolates (GH01-GH16) with similar colony morphology were obtained. The colonies were initially white, gradually turning to olive-green on the surface and black on the underside after 7 days. Microscopically, the conidia were aseptate, 1-septate, two-septate, and muriform, 2.6-4.5 × 2.9-27.6 µm (n=50). Pycnidia ranged in size from 120.2 to 135.5 × 112.4 to 118.6 µm (n=20). Those morphological characters matched the descriptions of Neoscytalidium dimidiatum (previously N. novaehollandiae) (Alizadeh et al. 2022; Pavlic et al. 2008). For molecular identification, genomic DNA of GH01-GH16 were extracted from fresh mycelia. The internal transcribed spacer (ITS), large subunit ribosomal RNA gene (LSU), and translation elongation factor 1-alpha (EF1-α) gene were amplified using the primer sets ITS1/ITS4 (White 1990), LRoR/LR5 (Vilgalys and Hester 1990) and EF1-728F/EF1-986R (Carbone and Kohn 1999). The sequences were deposited in GenBank (accession No. OP379832, OQ096643-OQ096657 for ITS, OP389048, OQ127403-OQ127417 for LSU, and OQ136617, OQ586044-OQ586058 for EF1-α). The ITS sequence had 100% identity (505/505 bp) to MT362600. Similarly, the LSU and EF1-α sequences were found to be identical to MW883823 (100%, 821/821 bp) and KX464763(99%, 256/258 bp), respectively. Pathogenicity was tested on one-year-old healthy S. japonicum seedlings. Spores of representative isolate GH01 were produced on PDA by incubating for 7-days at 28℃. Conidia were washed with sterile water. Five trees were inoculated with 1 × 106 conidia/ml conidial suspensions and five trees were sprayed with sterile water. All trees were covered with plastic bags for 24 h and kept at 25°C in a greenhouse. Signs and symptoms were similar to those observed in field collections one month after inoculation, while no symptoms occurred on the controls. The original fungus was successfully reisolated from the inoculated trees and was identified as N. dimidiatum following the methods described above. N. dimidiatum has been reported in many Asian country such as Malaysia, India, Turkey, and Iran(Akgül et al. 2019; Alizadeh et al. 2022; Khoo et al. 2023; Salunkhe et al. 2023). To our knowledge, this is the first report of N. dimidiatum associated with branch dieback of S. japonicum in China. Our findings have expanded the host range of N. dimidiatum in China and provides a theoretical basis for the diagnosis and treatment of the disease.

14.
Angew Chem Int Ed Engl ; 62(15): e202219230, 2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-36780319

RESUMEN

Manganese-rich layered oxide cathodes of sodium-ion batteries (SIBs) are extremely promising for large-scale energy storage owing to their high capacities and cost effectiveness, while the Jahn-Teller (J-T) distortion and low operating potential of Mn redox largely hinder their practical applications. Herein, we reveal that annealing in argon rather than conventional air is a universal strategy to comprehensively upgrade the Na-storage performance of Mn-based oxide cathodes. Bulk oxygen vacancies are introduced via this method, leading to reduced Mn valence, lowered Mn 3d-orbital energy level, and formation of the new-concept Mn domains. As a result, the energy density of the model P2-Na0.75 Mg0.25 Mn0.75 O2 cathode increases by ≈50 % benefiting from the improved specific capacity and operating potential of Mn redox. The Mn domains can disrupt the cooperative J-T distortion, greatly promoting the cycling stability. This exciting finding opens a new avenue towards high-performance Mn-based oxide cathodes for SIBs.

15.
Chembiochem ; 23(13): e202200038, 2022 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-35442561

RESUMEN

Protopanaxadiol (PPD), a main ginseng metabolite, exerts powerful anticancer effects against multiple types of cancer; however, its cellular targets remain elusive. Here, we synthesized a cell-permeable PPD probe via introducing a bifunctional alkyne-containing diazirine photo-crosslinker and performed a photoaffinity labeling-based chemoproteomic study. We identified retinoblastoma binding protein 4 (RBBP4), a chromatin remodeling factor, as an essential cellular target of PPD in HCT116 colorectal cancer cells. PPD significantly decreased RBBP4-dependent trimethylation at lysine 27 of histone H3 (H3K27me3), a crucial epigenetic marker that correlates with histologic signs of colorectal cancer aggressiveness, and PPD inhibition of proliferation and migration of HCT116 cells was antagonized by RBBP4 RNA silencing. Collectively, our study highlights a previously undisclosed anti-colorectal cancer cellular target of the ginseng metabolite and advances the fundamental understanding of RBBP4 functions via a chemical biology strategy.


Asunto(s)
Neoplasias Colorrectales , Panax , Sapogeninas , Neoplasias Colorrectales/tratamiento farmacológico , Células HCT116 , Humanos , Panax/química , Proteína 4 de Unión a Retinoblastoma/genética , Proteína 4 de Unión a Retinoblastoma/metabolismo , Sapogeninas/farmacología , Factores de Transcripción/metabolismo
16.
Lett Appl Microbiol ; 74(6): 901-908, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35218013

RESUMEN

In the microbiome, probiotics modulate oral diseases. In this study, Streptococcus strain C17T was isolated from the oropharynx of a 5-year-old healthy child, and its potential probiotic properties were analysed using human bronchial epithelial cells (16-HBE) used as an in vitro oropharyngeal mucosal model. The results demonstrated that the C17T strain showed tolerance to moderate pH ranges of 4-5 and 0·5-1% bile. However, it was more tolerant to 0·5% bile than 1% bile. It also demonstrated an ability to accommodate maladaptive oropharyngeal conditions (i.e. tolerating lysozyme at 200 µg ml-1 ). It was also resistant to hydrogen peroxide at 0·8 mM. In addition, we found out that the strain possesses inhibitory activities against various common pathogenic bacteria. Furthermore, C17T was not cytotoxic to 16-HBE cells at different multiplicities of infection. Scanning electron microscopy disclosed that C17T adhesion to 16-HBE cells. Competition, exclusion and displacement assays showed that it had good anti-adhesive effect against S. aureus. The present study revealed that Streptococcus strain C17T is a potentially efficacious oropharyngeal probiotic.


Asunto(s)
Salud Bucal , Probióticos , Streptococcus , Adhesión Bacteriana , Preescolar , Humanos , Probióticos/farmacología , Staphylococcus aureus/efectos de los fármacos , Streptococcus/efectos de los fármacos , Streptococcus/genética
17.
Antonie Van Leeuwenhoek ; 114(2): 113-127, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33387140

RESUMEN

Using the culturomics approach, we isolated a new Streptococcus species, strain C17T, from the oropharynx mucosa sample of a healthy 5-year-old child living in Shenyang, China. We studied the phenotypic, phylogenetic, and genomic characteristics of strain C17T, which was identified as a Gram-positive, coccus-shaped, non-motile, aerobic, catalase-negative bacteria. Its growth temperatures ranged from 20 to 42 °C, with optimal growth at 37 °C. Acid production could be inhibited by two sugars, trehalose and raffinose. In C17T, the reactions for enzyme lipase (C14) were confirmed to be negative, whereas those for alkaline phosphatase, α-glucosidase, and hippuric acid hydrolysis were positive. The C17T genome contained 2,189,419 base pairs (bp), with an average G+C content of 39.95%, encoding 2092 genes in total. The 16S ribosomal RNA sequence showed 99.8% similarity with the newly identified Streptococcus pseudopneumoniae ATCC BAA-960T. The main fatty acid components in C17T were C16:0, C18:1 w7c, C18:0, and C18:1 w9c, all of which can be found in other species of the Streptococcus genus. Strain C17T showed high susceptibility to clindamycin, linezolid, vancomycin, chloramphenicol, and cefepime, and moderate susceptibility to erythromycin. The obtained dDDH value between strain C17T and the closest species was 52.9%. In addition, the whole genome sequence of strain C17T had an 82.21-93.40% average nucleotide identity (ANI) with those strains of closely related Streptococcus species, indicating that the strain C17T was unique among all Streptococcus species. Based on these characteristics, we determine that C17T is a novel species, named Streptococcus symci sp. nov. (= GDMCC 1.1633 = JCM 33582).


Asunto(s)
Fosfolípidos , Streptococcus , Técnicas de Tipificación Bacteriana , Preescolar , ADN Bacteriano/genética , Ácidos Grasos , Genómica , Humanos , Hibridación de Ácido Nucleico , Orofaringe , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Streptococcus/genética
18.
Antonie Van Leeuwenhoek ; 114(8): 1293-1305, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34110551

RESUMEN

Stingless bees are the main pollinators in tropical and subtropical regions. However, there are only a few studies on the structure and composition of bacteria in the gut and beebread of stingless bees, especially in China. To address this shortage of information, we characterized the microbiota of three common species of stingless bees (Lepidotrigona terminata, Lepidotrigona ventralis and Tetragonula pagdeni) and beebread samples of T. pagdeni. The results showed that the gut of stingless bees contained a set of dominant bacteria, including Acetobacter-like, Snodgrassella, Lactobacillus, Psychrobacter, Pseudomonas, Bifidobacterium and other species. The gut microbiota structures of the three stingless bees were different, and the abundances of bacterial species in the gut varied between communities of the same bee species. The reasons for this are manifold and may include food preference, age and genetic differences. In addition, the abundances of Lactobacillus, Carnimonas, Escherichia-Shigella, Acinetobacter and other species were high in the beebread of stingless bees. In conclusion, our findings reveal the bacteria composition and structure of the gut and beebread of stingless bees in China and deepen our understanding of the dominant bacteria of the gut and beebread of stingless bees.


Asunto(s)
Microbioma Gastrointestinal , Microbiota , Própolis , Animales , Bacterias/genética , Abejas , China
19.
Cochrane Database Syst Rev ; 4: CD012789, 2021 04 14.
Artículo en Inglés | MEDLINE | ID: mdl-33849080

RESUMEN

BACKGROUND: Trigger finger is a common hand condition that occurs when movement of a finger flexor tendon through the first annular (A1) pulley is impaired by degeneration, inflammation, and swelling. This causes pain and restricted movement of the affected finger. Non-surgical treatment options include activity modification, oral and topical non-steroidal anti-inflammatory drugs (NSAIDs), splinting, and local injections with anti-inflammatory drugs. OBJECTIVES: To review the benefits and harms of non-steroidal anti-inflammatory drugs (NSAIDs) versus placebo, glucocorticoids, or different NSAIDs administered by the same route for trigger finger. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL, CNKI (China National Knowledge Infrastructure), ProQuest Dissertations and Theses, www.ClinicalTrials.gov, and the WHO trials portal until 30 September 2020. We applied no language or publication status restrictions. SELECTION CRITERIA: We searched for randomised controlled trials (RCTs) and quasi-randomised trials of adult participants with trigger finger that compared NSAIDs administered topically, orally, or by injection versus placebo, glucocorticoid, or different NSAIDs administered by the same route. DATA COLLECTION AND ANALYSIS: Two or more review authors independently screened the reports, extracted data, and assessed risk of bias and GRADE certainty of evidence. The seven major outcomes were resolution of trigger finger symptoms, persistent moderate or severe symptoms, recurrence of symptoms, total active range of finger motion, residual pain, patient satisfaction, and adverse events. Treatment effects were reported as risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs). MAIN RESULTS: Two RCTs conducted in an outpatient hospital setting were included (231 adult participants, mean age 58.6 years, 60% female, 95% to 100% moderate to severe disease). Both studies compared a single injection of a non-selective NSAID (12.5 mg diclofenac or 15.0 mg ketorolac) given at lower than normal doses with a single injection of a glucocorticoid (triamcinolone 20 mg or 5 mg), with maximum follow-up duration of 12 weeks or 24 weeks. In both studies, we detected risk of attrition and performance bias. One study also had risk of selection bias. The effects of treatment were sensitive to assumptions about missing outcomes. All seven outcomes were reported in one study, and five in the other. NSAID injection may offer little to no benefit over glucocorticoid injection, based on low- to very low-certainty evidence from two trials. Evidence was downgraded for bias and imprecision. There may be little to no difference between groups in resolution of symptoms at 12 to 24 weeks (34% with NSAIDs, 41% with glucocorticoids; absolute effect 7% lower, 95% confidence interval (CI) 16% lower to 5% higher; 2 studies, 231 participants; RR 0.83, 95% CI 0.62 to 1.11; low-certainty evidence). The rate of persistent moderate to severe symptoms may be higher at 12 to 24 weeks in the NSAIDs group (28%) compared to the glucocorticoid group (14%) (absolute effect 14% higher, 95% CI 2% to 33% higher; 2 studies, 231 participants; RR 2.03, 95% CI 1.19 to 3.46; low-certainty evidence). We are uncertain whether NSAIDs result in fewer recurrences at 12 to 24 weeks (1%) compared to glucocorticoid (21%) (absolute effect 20% lower, 95% CI 21% to 13% lower; 2 studies, 231 participants; RR 0.07, 95% CI 0.01 to 0.38; very low-certainty evidence). There may be little to no difference between groups in mean total active motion at 24 weeks (235 degrees with NSAIDs, 240 degrees with glucocorticoid) (absolute effect 5% lower, 95% CI 34.54% lower to 24.54% higher; 1 study, 99 participants; MD -5.00, 95% CI -34.54 to 24.54; low-certainty evidence). There may be little to no difference between groups in residual pain at 12 to 24 weeks (20% with NSAIDs, 24% with glucocorticoid) (absolute effect 4% lower, 95% CI 11% lower to 7% higher; 2 studies, 231 participants; RR 0.84, 95% CI 0.54 to 1.31; low-certainty evidence). There may be little to no difference between groups in participant-reported treatment success at 24 weeks (64% with NSAIDs, 68% with glucocorticoid) (absolute effect 4% lower, 95% CI 18% lower to 15% higher; 1 study, 121 participants; RR 0.95, 95% CI 0.74 to 1.23; low-certainty evidence). We are uncertain whether NSAID injection has an effect on adverse events at 12 to 24 weeks (1% with NSAIDs, 1% with glucocorticoid) (absolute effect 0% difference, 95% CI 2% lower to 3% higher; 2 studies, 231 participants; RR 2.00, 95% CI 0.19 to 21.42; very low-certainty evidence). AUTHORS' CONCLUSIONS: For adults with trigger finger, by 24 weeks' follow-up, results from two trials show that compared to glucocorticoid injection, NSAID injection offered little to no benefit in the treatment of trigger finger. Specifically, there was no difference in resolution, symptoms, recurrence, total active motion, residual pain, participant-reported treatment success, or adverse events.


Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Diclofenaco/uso terapéutico , Ketorolaco/uso terapéutico , Trastorno del Dedo en Gatillo/tratamiento farmacológico , Antiinflamatorios no Esteroideos/administración & dosificación , Sesgo , Diclofenaco/administración & dosificación , Femenino , Glucocorticoides/administración & dosificación , Glucocorticoides/uso terapéutico , Humanos , Ketorolaco/administración & dosificación , Masculino , Persona de Mediana Edad , Placebos/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento , Triamcinolona/administración & dosificación , Triamcinolona/uso terapéutico
20.
Curr Microbiol ; 78(7): 2821-2827, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34031726

RESUMEN

A Gram-positive, catalase-negative, coccus-shaped, chain-forming organism isolated from the oropharynx of a healthy child in Shenyang, China, was subjected to phenotypic and molecular taxonomic analyses. 16S rRNA sequence analysis indicated that this bacterium represents a new member of the genus Streptococcus and is closely related to Streptococcus oralis subsp. dentisani DSM 27088. According to DNA-DNA hybridization analysis, strain D19T was less than 70% similar to other strains with close genetic relationships. Fatty acid analysis, physiological, and biochemical tests showed that strain D19T was different from the published Streptococcus species. The genome of strain D19T is 2,023,003 bp long with a GC content of 39.9 mol%. It contains 1889 protein-coding genes and 50 RNA genes. These results show that Streptococcus shenyangsis sp. nov. strain D19T is a new species.


Asunto(s)
Orofaringe , Streptococcus , Técnicas de Tipificación Bacteriana , Niño , China , ADN Bacteriano/genética , Humanos , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Streptococcus/genética
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