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1.
Extremophiles ; 26(2): 19, 2022 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-35661272

RESUMEN

An alkali and salt-tolerating strain FJAT-44876T was isolated from the bauxite residue sample. The 16S rRNA gene sequence and phylogenetic analysis suggest that strain FJAT-44876T was a member of the genus Evansella. It grew at 15-45 â„ƒ (optimum 20-25 â„ƒ) and pH 6.5-11.0 (optimum pH 8.0-9.0) with 0-20% (w/v) NaCl (optimum 6-8%). The major fatty acids were anteiso-C15:0, iso-C15:0, anteiso-C17:0, iso-C17:0, and C16:0. The cell wall peptidoglycan contained meso-diaminopimelic acid and MK-7 as the menaquinone. The major polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, and phosphatidylglycerol. The genomic DNA G+C content was 38.2%. The average nucleotide identity values between strain FJAT-44876T and closely related members were below the cutoff level for species delineation. Thus, based on the above results, strain FJAT-44876T represents a novel species of the genus Evansella, for which the name Evansella halocellulosilytica sp. nov., is proposed. The type strain is FJAT-44876T (=CCTCC AB 2016264T = DSM 104633T).


Asunto(s)
Bacillaceae , Bacillus , Álcalis , Óxido de Aluminio , Bacillaceae/genética , Bacillus/genética , Bacterias/genética , Técnicas de Tipificación Bacteriana , Celulosa , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Fosfolípidos , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Microbiología del Suelo
2.
Int J Syst Evol Microbiol ; 70(11): 5717-5724, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32956031

RESUMEN

Two anaerobic bacteria, designated strains SYSU GA16112T and SYSU GA16107, were isolated from a hot spring in Tengchong County, Yunnan Province, south-west PR China. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains SYSU GA16112T and SYSU GA16107 belong to the family Dysgonamonadaceae. Cells of strains SYSU GA16112T and SYSU GA16107 were Gram-stain-negative, rod-shaped and non-motile. The major fatty acids (>10 %) of strains SYSU GA16112T and SYSU GA16107 were identified as anteiso-C15 : 0 and anteiso-C17 : 0 3OH. The polar lipid profile of strain SYSU GA16112T was found to consist of phosphatidylethanolamine, two unidentified aminophospholipids, two unidentified phosphoglycolipids, two unidentified aminolipids and one unidentified polar lipid, while that of strain SYSU GA16107 consisted of phosphatidylethanolamine, two unidentified polar lipids, three unidentified aminophospholipids, two unidentified phosphoglycolipids and one unidentified aminolipid. The genomic DNA G+C contents of strains SYSU GA16112T and SYSU GA16107 were determined to be 41.90 and 41.89 %, respectively, and the average nucleotide identity value between them was 99.99 %. Based on their morphological and physiological properties, and results of phylogenetic analyses, strains SYSU GA16112T and SYSU GA16107 are considered to represent a novel species of a novel genus, for which the name Seramator thermalis gen. nov., sp. nov. (type strain SYSU GA16112T=CGMCC 1.5281T=KCTC 15753T) is proposed.


Asunto(s)
Bacteroidetes/clasificación , Manantiales de Aguas Termales/microbiología , Filogenia , Técnicas de Tipificación Bacteriana , Bacteroidetes/aislamiento & purificación , Composición de Base , Metabolismo de los Hidratos de Carbono , Celulosa/metabolismo , China , ADN Bacteriano/genética , Ácidos Grasos/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Xilanos/metabolismo
3.
Antonie Van Leeuwenhoek ; 113(10): 1467-1477, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32748077

RESUMEN

A ß-glucosidase gene (bsbgl1a) from Bacillus sp. CGMCC 1.16541 was expressed in Escherichia coli BL21 and subsequently characterized. The amino acid sequence shared 83.64% identity with ß-glucosidase (WP_066390903.1) from Fictibacillus phosphorivorans. The recombinant ß-glucosidase (BsBgl1A) had a molecular weight of 52.2 kDa and could hydrolyze cellobiose, cellotriose, cellotetrose, p-nitrophenyl-ß-D-glucopyranoside (pNPG), and p-nitrophenyl-ß-D-xylopyranoside (pNPX). Optimal activity for BsBgl1A was recorded at 45 °C with a pH between 5.6 and 7.6, and 100% of its activity was maintained after a 24 h incubation between pH 4 and 9. Kinetic characterization revealed an enzymatic turnover (Kcat) of 616 ± 2 s-1 (with cellobiose) and 3.5 ± 0.1 s-1 (with p-nitrophenyl-ß-D-glucopyranoside). Interestingly, the recombinant enzyme showed cupric ion (Cu2+), sodium dodecyl sulfate (SDS) and alcohol tolerance at 10 mM for Cu2+ and 10% for both SDS and alcohol. Additionally, BsBgl1A had high tolerance for glucose (Ki = 2095 mM), which is an extremely desirable feature for industrial applications. Following the addition of BsBgl1A (0.05 mg/ml) to a commercial cellulase reaction system, glucose yields from sugarcane bagasse increased 100% after 1 day at 45 °C. This work identifies a Cu2+, SDS, alcohol, and glucose tolerant GH1 ß-glucosidase with potential applications in the hydrolysis of cellulose for the bioenergy industry.


Asunto(s)
Adaptación Fisiológica , Bacillus/efectos de los fármacos , Bacillus/enzimología , Cobre/farmacología , Etanol/farmacología , Glucosa/farmacología , Ácidos Sulfónicos/farmacología , beta-Glucosidasa/metabolismo , Bacillus/genética , Celulosa/química , Estabilidad de Enzimas/efectos de los fármacos , Concentración de Iones de Hidrógeno , Hidrólisis , Proteínas Recombinantes , Temperatura , beta-Glucosidasa/genética , beta-Glucosidasa/aislamiento & purificación
4.
Anaerobe ; 61: 102075, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31326441

RESUMEN

In our search for novel anaerobes with potential carbohydrate polymers degrading activity, we have isolated a xylan-degrading bacterial strain SYSU GA17129T from an anammox bacteria dominant wastewater treatment plant. Phylogenetic analysis of the 16S rRNA gene sequence indicated the strain SYSU GA17129T belong to the order Clostridiales and shared highest sequence identity with Caldicoprobacter faecalis DSM 20678T (89.9%). The strain was thermophilic, obligately anaerobic, non-motile and rod shaped. Optimum growth of the strain was observed at 45 °C, pH 8.0 and in the presence of 0.5% NaCl (w/v). The chemotaxonomic features of the strain SYSU GA17129T comprised of C14:0 FAME, iso-C15:0 FAME and C16:0 FAME as the major fatty acids (>10%), diphosphatidylglycerol, phosphatidylinositol mannoside, an unidentified phospholipid, three unidentified polar lipids and two unidentified glycolipids as its polar lipids, and meso-diaminopimelic acid (meso-DAP) as the diamino acid in peptidoglycan. The G + C content of the genomic DNA was 35.9%. The strain could be distinguished from other defined families within the order Clostridiales by the differences in phenotypic and physiological characteristics, distinct phylogenetic lineage in 16S rRNA gene- and genome-based phylogenies and low genomic relatedness index. Based on these distinguishing properties, strain SYSU GA17129T is proposed to represent a new species of a new genus Xylanivirga thermophila gen. nov., sp. nov., within a new family Xylanivirgaceae fam. nov. The type species of the new taxon is SYSU GA17129T (=KCTC 15754T = CGMCC 1.5282T). This strain is characterized within the order Clostridiales, class Clostridia of the phylum Firmicutes.


Asunto(s)
Bacterias Anaerobias/aislamiento & purificación , Bacterias Anaerobias/fisiología , Biodegradación Ambiental , Clostridiales/aislamiento & purificación , Clostridiales/fisiología , Aguas Residuales/microbiología , Xilanos/metabolismo , Bacterias Anaerobias/clasificación , Bacterias Anaerobias/genética , Metabolismo de los Hidratos de Carbono , Carbohidratos , Clostridiales/clasificación , Clostridiales/genética , Filogenia , Plásticos , Polímeros , ARN Ribosómico 16S/genética , Administración de Residuos
5.
Small ; 14(36): e1801008, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30095225

RESUMEN

Phototherapy is a promising treatment method for cancer therapy. However, the various factors have greatly restricted phototherapy development, including the poor accumulation of photosensitizer in tumor, hypoxia in solid tumor tissue and systemic phototoxicity. Herein, a mitochondrial-targeted multifunctional dye-anchored manganese oxide nanoparticle (IR808@MnO NP) is developed for enhancing phototherapy of cancer. In this nanoplatform, IR808 as a small molecule dye acts as a tumor targeting ligand to make IR808@MnO NPs with capacity to actively target tumor cells and relocate finally in the mitochondria. Meanwhile, continuous production of oxygen (O2 ) and regulation of pH induced by the high reactivity and specificity of MnO NPs toward mitochondrial endogenous hydrogen peroxide (H2 O2 ) could effectively modulate tumor hypoxia and lessen the tumor subacid environment. Large amounts of reactive oxide species (ROS) are generated during the reaction process between H2 O2 and MnO NPs. Furthermore, under laser irradiation, IR808 in IR808@MnO NPs turns O2 into a highly toxic singlet oxygen (1 O2 ) and generates hyperthermia. The results indicate that IR808@MnO NPs have the high efficiency of specific targeting of tumors, relieving tumor subacid environment, improving the tumor hypoxia environment, and generating large amounts of ROS to kill tumor cells. It is expected to have a wide application in treating cancer.


Asunto(s)
Neoplasias de la Mama/terapia , Colorantes/química , Compuestos de Manganeso/química , Mitocondrias/metabolismo , Nanopartículas/química , Óxidos/química , Fototerapia , Animales , Materiales Biocompatibles/química , Neoplasias de la Mama/patología , Supervivencia Celular , Femenino , Humanos , Células MCF-7 , Ratones Endogámicos BALB C , Nanopartículas/ultraestructura , Especies Reactivas de Oxígeno/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
6.
Int J Syst Evol Microbiol ; 64(Pt 2): 650-656, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24158953

RESUMEN

Two thermophilic bacterial strains, designated YIM 77925(T) and YIM 77777, were isolated from two hot springs, one in the Hydrothermal Explosion (Shuirebaozhaqu) area and Frog Mouth Spring in Tengchong county, Yunnan province, south-western China. The taxonomic positions of the two isolates were investigated by a polyphasic approach. Cells of the two strains were Gram-stain-negative, aerobic and rod-shaped. They were able to grow at 50-70 °C, pH 6.0-8.0 and with a NaCl tolerance up to 0.5% (w/v). Colonies are circular, convex, non-transparent and produce yellow pigment. Phylogenetic analyses based on 16S rRNA gene sequences comparison clearly demonstrated that strains YIM 77925(T) and YIM 77777 represent members of the genus Thermus, and they also detected low-level similarities of 16S rRNA gene sequences (below 97%) compared with all other species in this genus. Their predominant menaquinone was MK-8. The genomic DNA G+C contents of strains YIM 77925(T) and YIM 77777 were 65.6 mol% and 67.2 mol%, respectively. Based on the results of physiological and biochemical tests and phylogenetic analyses, strains YIM 77925(T) and YIM 77777 could not be classified as representing any species of the genus Thermus with a validly published name. Thus the two strains are considered to represent a novel species of the genus Thermus, for which the name Thermus caliditerrae sp. nov. is proposed. The type strain is YIM 77925(T) ( = DSM 25901(T) = CCTCC 2012061(T)).


Asunto(s)
Sedimentos Geológicos/microbiología , Manantiales de Aguas Termales/microbiología , Filogenia , Thermus/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Glucolípidos/química , Datos de Secuencia Molecular , Fosfolípidos/química , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Thermus/genética , Thermus/aislamiento & purificación , Vitamina K 2/análogos & derivados , Vitamina K 2/química
7.
PLoS One ; 19(7): e0305218, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38968236

RESUMEN

This meta-analysis aims to assess the success rate of pulpotomy in the treatment of permanent teeth with carious pulp exposure and to compare the efficacy of different capping materials. Randomized controlled trials were searched in PubMed, EMBASE, Web of Science, Clinicaltrial.gov, and Cochrane Library until August 31, 2023. The pooled success rate was estimated in the overall population and in subgroups. Additional analyses comparing different capping materials using odds ratio (OR) and 95% confidence interval (95%CI) were performed. The certainty of evidence was graded using the GRADE approach. A total of 25 randomized trials with an average follow-up duration ≥ 12 months were finally included. The overall success rate of pulpotomy was 86.7% (95%CI: 82.0-90.7%). The success rate was not significantly affected by root development, pulpotomy type, and follow-up duration. Teeth with irreversible pulpitis had a relatively lower success rate than teeth with normal pulp or reversible pulpitis (82.4% [95%CI: 74.6-89.0%] vs 92.0% [95%CI: 87.9-95.4%], P = 0.013). Directly compared to conventional calcium hydroxide, mineral trioxide aggregate (88.2% vs 79.1%, OR = 2.41, 95%CI: 1.28-4.51, P = 0.006) and Biodentine (97.5% vs 82.9%, OR = 6.03, 95%CI: 0.97-37.6, P = 0.054) had higher successful rates. No significant difference between MTA and other biomaterials was found. The results were graded as very low to low certainty of evidence. In conclusion, pulpotomy is an effective treatment of permanent teeth with carious pulp exposure. Mineral trioxide aggregate and Biodentine can be recommended with more favorable outcomes as capping materials.


Asunto(s)
Caries Dental , Pulpotomía , Ensayos Clínicos Controlados Aleatorios como Asunto , Humanos , Pulpotomía/métodos , Caries Dental/terapia , Resultado del Tratamiento , Compuestos de Calcio/uso terapéutico , Dentición Permanente , Silicatos/uso terapéutico , Compuestos de Aluminio/uso terapéutico , Combinación de Medicamentos , Óxidos/uso terapéutico , Recubrimiento de la Pulpa Dental/métodos , Pulpitis/terapia , Hidróxido de Calcio/uso terapéutico , Exposición de la Pulpa Dental/terapia
8.
J Hazard Mater ; 474: 134728, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-38805824

RESUMEN

Microplastics are accumulating rapidly in aquatic ecosystems, providing habitats for pathogens and vectors for antibiotic resistance genes (ARGs), potentially increasing pathogenic risks. However, few studies have considered microplastics as particulate organic matter (POM) to elucidate their pathogenic risks and underlying mechanisms. Here, we performed microcosm experiments with microplastics and natural POM (leaves, algae, soil), thoroughly investigating their distinct effects on the community compositions, functional profiles, opportunistic pathogens, and ARGs in Particle-Associated (PA) and Free-Living (FL) bacterial communities. We found that both microplastics and leaves have comparable impacts on microbial community structures and functions, enriching opportunistic pathogens and ARGs, which may pose potential environmental risks. These effects are likely driven by their influences on water properties, including dissolved organic carbon, nitrate, DO, and pH. However, microplastics uniquely promoted pathogens as keystone species and further amplified their capacity as hosts for ARGs, potentially posing a higher pathogenic risk than natural POM. Our research also emphasized the importance of considering both PA and FL bacteria when assessing microplastic impacts, as they exhibited different responses. Overall, our study elucidates the role and underlying mechanism of microplastics as an emerging POM in intensifying pathogenic risks of aquatic ecosystems in comparison with conventional natural POM.


Asunto(s)
Bacterias , Ecosistema , Microplásticos , Material Particulado , Contaminantes Químicos del Agua , Microplásticos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , Material Particulado/toxicidad , Bacterias/genética , Bacterias/efectos de los fármacos , Hojas de la Planta/microbiología , Microbiota/efectos de los fármacos , Microbiología del Agua
9.
Adv Healthc Mater ; 13(22): e2400675, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38843486

RESUMEN

Implantable sensors, especially ion sensors, facilitate the progress of scientific research and personalized healthcare. However, the permanent retention of implants induces health risks after sensors fulfill their mission of chronic sensing. Biodegradation is highly anticipated; while; biodegradable chemical sensors are rare due to concerns about the leakage of harmful active molecules after degradation, such as ionophores. Here, a novel biodegradable fiber calcium ion sensor is introduced, wherein ionophores are covalently bonded with bioinert nanoparticles to replace the classical ion-selective membrane. The fiber sensor demonstrates comparable sensing performance to classical ion sensors and good flexibility. It can monitor the fluctuations of Ca2+ in a 4-day lifespan in vivo and biodegrade in 4 weeks. Benefiting from the stable bonding between ionophores and nanoparticles, the biodegradable sensor exhibits a good biocompatibility after degradation. Moreover, this approach of bonding active molecules on bioinert nanoparticles can serve as an effective methodology for minimizing health concerns about biodegradable chemical sensors.


Asunto(s)
Calcio , Nanopartículas , Nanopartículas/química , Calcio/química , Animales , Ratones , Materiales Biocompatibles/química , Implantes Absorbibles , Iones/química , Técnicas Biosensibles/métodos
10.
Int J Syst Evol Microbiol ; 63(Pt 12): 4675-4682, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23950149

RESUMEN

Several closely related, thermophilic and cellulolytic bacterial strains, designated JKG1(T), JKG2, JKG3, JKG4 and JKG5, were isolated from a cellulolytic enrichment (corn stover) incubated in the water column of Great Boiling Spring, NV. Strain JKG1(T) had cells of diameter 0.7-0.9 µm and length ~2.0 µm that formed non-branched, multicellular filaments reaching >300 µm. Spores were not formed and dense liquid cultures were red. The temperature range for growth was 45-65 °C, with an optimum of 55 °C. The pH range for growth was pH 5.6-9.0, with an optimum of pH 7.5. JKG1(T) grew as an aerobic heterotroph, utilizing glucose, sucrose, xylose, arabinose, cellobiose, CM-cellulose, filter paper, microcrystalline cellulose, xylan, starch, Casamino acids, tryptone, peptone, yeast extract, acetate, citrate, lactate, pyruvate and glycerol as sole carbon sources, and was not observed to photosynthesize. The cells stained Gram-negative. Phylogenetic analysis using 16S rRNA gene sequences placed the new isolates in the class Chloroflexia, but distant from other cultivated members, with the highest sequence identity of 82.5 % to Roseiflexus castenholzii. The major quinone was menaquinone-9; no ubiquinones were detected. The major cellular fatty acids (>5 %) were C18 : 0, anteiso-C17 : 0, iso-C18 : 0, iso-C17 : 0, C16 : 0, iso-C16 : 0 and C17 : 0. The peptidoglycan amino acids were alanine, ornithine, glutamic acid, serine and asparagine. Whole-cell sugars included mannose, rhamnose, glucose, galactose, ribose, arabinose and xylose. Morphological, phylogenetic and chemotaxonomic results suggest that JKG1(T) is representative of a new lineage within the class Chloroflexia, which we propose to designate Kallotenue papyrolyticum gen. nov., sp. nov., Kallotenuaceae fam. nov., Kallotenuales ord. nov. The type strain of Kallotenue papyrolyticum gen. nov., sp. nov. is JKG1(T) ( = DSM 26889(T) = JCM 19132(T)).


Asunto(s)
Celulosa/metabolismo , Chloroflexi/clasificación , Manantiales de Aguas Termales/microbiología , Filogenia , Chloroflexi/genética , Chloroflexi/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/química , Datos de Secuencia Molecular , Nevada , Peptidoglicano/química , ARN Ribosómico 16S/genética , Vitamina K 2/análogos & derivados , Vitamina K 2/química
11.
Adv Healthc Mater ; 12(31): e2301610, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37717208

RESUMEN

Repairing high-load connective tissues, such as ligaments, by surgically implanting artificial grafts after injury is challenging because they lack biointegration with host bones for stable interfaces. Herein, a high-performance helical composite fiber (HCF) ligament by wrapping aligned carbon nanotube (CNT) sheets around polyester fibers is proposed. Anterior cruciate ligament (ACL) reconstruction surgery shows that HCF grafts could induce effective bone regeneration, thus allowing the narrowing of bone tunnel defects. Such repair of the bone tunnel is in strong contrast to the tunnel enlargement of more than 50% for commercial artificial ligaments made from bare polyester fibers. Rats reconstructed with this HCF ligament show normal jumping, walking, and running without limping. This work allows bone regeneration in vivo through a one-step surgery without seeding cells or transforming growth factors, thereby opening an avenue for high-performance artificial tissues.


Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior , Nanotubos de Carbono , Animales , Ratas , Ligamento Cruzado Anterior/trasplante , Poliésteres
12.
ACS Sens ; 7(1): 151-158, 2022 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-34788009

RESUMEN

Polymer-carbon nanocomposite sensor is a promising molecular sensing device for electronic nose (e-nose) due to its printability, variety of polymer materials, and low operation temperature; however, the lack of stability in an air environment has been an inevitable issue. Here, we demonstrate a design concept for realizing long-term stability in a polyethylene glycol (PEG)-carbon black (CB) nanocomposite sensor by understanding the underlying phenomena that cause sensor degradation. Comparison of the sensing properties and infrared spectroscopy on the same device revealed that the oxidation-induced consumption of PEG is a crucial factor for the sensor degradation. According to the mechanism, we introduced an antioxidizing agent (i.e., ascorbic acid) into the PEG-CB nanocomposite sensor to suppress the PEG oxidation and successfully demonstrated the long-term stability of sensing properties under an air environment for 30 days, which had been difficult in conventional polymer-carbon nanocomposite sensors.


Asunto(s)
Nanocompuestos , Polietilenglicoles , Carbono/química , Nanocompuestos/química , Polietilenglicoles/química , Polímeros/química , Hollín
13.
Chemosphere ; 296: 133995, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35176304

RESUMEN

Estuaries are one of the most crucial areas for the transformation and burial of terrestrial organic carbon (TerrOC), playing an important role in the global carbon cycle. While the transformation and degradation of TerrOC are mainly driven by microorganisms, the specific taxa and degradation processes involved remain largely unknown in estuaries. We collected surface sediments from 14 stations along the longitudinal section of the Pearl River Estuary (PRE), P. R. China. By combining analytical chemistry, metagenomics, and bioinformatics methods, we analyzed composition, source and degradation pathways of lignin/lignin-derived aromatic fragments and their potential decomposers in these samples. A diversity of bacterial and archaeal taxa, mostly those from Proteobacteria (Deltaproteobacteria, Gammaproteobacteria etc.), including some lineages (e.g., Nitrospria, Polyangia, Tectomicrobia_uc) not previously implicated in lignin degradation, were identified as potential polymeric lignin or its aromatic fragments degraders. The abundance of lignin degradation pathways genes exhibited distinct spatial distribution patterns with the area adjacent to the outlet of Modaomen as a potential degradation hot zone and the Syringyl lignin fragments, 3,4-PDOG, and 4,5-PDOG pathways as the primary potential lignin aromatic fragments degradation processes. Notably, the abundance of ferulic acid metabolic pathway genes exhibited significant correlations with degree of lignin oxidation and demethylation/demethoxylization and vegetation source. Additionally, the abundance of 2,3-PDOG degradation pathways genes also showed a positive significant correlation with degree of lignin oxidation. Our study provides a meaningful insight into the microbial ecology of TerrOC degradation in the estuary.


Asunto(s)
Estuarios , Ríos , Archaea/genética , Bacterias/genética , Carbono/análisis , China , Sedimentos Geológicos/microbiología , Lignina , Ríos/microbiología
14.
Adv Mater ; 33(40): e2103174, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34418193

RESUMEN

High-strength and reversible adhesion technology, which is a universal phenomenon in nature but remains challenging for artificial synthesis, is essential for the development of modern science. Existing adhesive designs without interface versatility hinder their application to arbitrary surfaces. Bioinspired by creeper suckers, a crystal-fiber reinforced polymer gel adhesive with ultrastrong adhesion strength and universal interface adaptability is creatively prepared via introducing a room-temperature crystallizable solvent into the polymer network. The gel adhesive formed by hydrogen bonding interaction between crystal fibers and polymer network can successfully realize over 9.82 MPa reversible adhesion strength for rough interface and 406.87 J m-2 peeling toughness for skin tissue. In situ anchoring is achieved for adapting to different geometrical surfaces. The adhesion performance can be significantly improved with the further increase of the interfacial roughness and hydrophilicity, whose dissipation mechanism is simulated by finite element analysis. The melting-crystallization equilibrium of the crystal fibers is proved by synchrotron radiation scattering. Accordingly, reversible phase-transition triggered by light and heat can realize the controlled adhere-detach recycle. Later adjustments to the monomers or crystals are expected to broaden its applications to various fields such as bioelectronics, electronic processing, and machine handling.


Asunto(s)
Adhesivos/química , Geles/química , Polímeros/química , Cristalización , Interacciones Hidrofóbicas e Hidrofílicas , Imidazoles/química , Temperatura , Rayos Ultravioleta
15.
Int J Biol Macromol ; 193(Pt A): 127-136, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34699889

RESUMEN

Traditional bioactive substances are often limited in practical application due to their poor stability and low solubility. Therefore, it is imperative to develop biocompatible high loading microgel carriers. In this study, a novel type of casein-porous starch microgel was prepared under ultra-high-pressure homogenization, by using porous starch with the honeycomb three-dimensional network porous structure. Molecular interaction force analysis and thermodynamic analysis showed that electrostatic interaction played a major role in the formation of microgels. Circular dichroism and Fourier transform infrared spectroscopy showed that homogenization and pH were the main factors, which affected the formation and structural stability of microgels. Compared with casein-glutinous rice starch microgels, the encapsulation efficiency and loading capacity of phycocyanin in casein-porous starch microgels were increased by 77.27% and 135.10%, respectively. Thus, casein-porous starch microgels could not only achieve a sustained release effect, but also effectively transport phycocyanin to the gastrointestinal tract of zebrafish, while achieving good fluorescence imaging in vivo. Ultimately, the prepared casein-porous starch microgels could enrich the nanocarriers material, and contribute to the research of safe and effective fluorescent imaging materials.


Asunto(s)
Caseínas/química , Microgeles/química , Ficocianina/química , Almidón/química , Animales , Porosidad , Solubilidad , Pez Cebra
16.
Emerg Infect Dis ; 16(2): 258-63, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20113556

RESUMEN

Tropheryma whipplei is the etiologic pathogenic agent of Whipple disease (WD), characterized by various clinical signs, such as diarrhea, weight loss, lymphadenopathy, and polyarthritis. PCR-based methods for diagnosis of WD have been developed. T. whipplei has been identified in saliva and stool samples from patients with WD and from healthy persons. T. whipplei DNA has also been found in bronchoalveolar lavage (BAL) samples of a child with pneumonia. We detected DNA of T. whipplei in 6 (3%) of 210 BAL samples collected in intensive care units by using 16S rDNA and specific quantitative PCR. We identified 4 novel genotypes of T. whipplei. In 1 case, T. whipplei was the only bacterium; in 4 others, it was associated with buccal flora. We suggest that T. whipplei should be investigated as an etiologic agent of pneumonia.


Asunto(s)
Infecciones por Actinomycetales/microbiología , Líquido del Lavado Bronquioalveolar/microbiología , Neumonía Bacteriana/microbiología , Tropheryma/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Infecciones Comunitarias Adquiridas/microbiología , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Vigilancia de la Población , Saliva/microbiología , Adulto Joven
17.
Mater Sci Eng C Mater Biol Appl ; 114: 111046, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32993992

RESUMEN

Anticancer drug-loaded hydrogels are a promising strategy for the local treatment of tumors such as breast cancer. We hypothesize that paclitaxel-nanoparticles-loaded double network (PTX-NPs-DN) hydrogel can deliver PTX locally and sustainably in the tumor resection cavity. In this study, hydrogels loaded with PTX-NPs were prepared via self-assembly of collagen and self-crosslinking of polyvinyl alcohol (PVA). The hydrogel with a porous structure has a compressive modulus of 33 kPa at a strain of 40%. In this system, PTX release presented a linear release kinetic over 10 days in vitro and higher accumulating concentrations of PTX in local adipose tissue than in plasma. The biocompatibility studies show that PTX-NPs-DN hydrogel did not induce cytotoxicity in different cell lines (MCF-7, L929s) and hemolysis in vitro nor inflammatory response in vivo. In vivo anti-tumor efficacy study, compared with all other groups, significantly decreased tumor weight and improved capacity to slow down tumor recurrences were observed in the group treated with PTX-NPs-DN hydrogel. In conclusion, this proof-of-concept study demonstrated the feasibility, tolerability and efficiency of PTX-NPs-DN hydrogel for the local treatment of breast cancer.


Asunto(s)
Neoplasias de la Mama , Nanopartículas , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Humanos , Hidrogeles , Paclitaxel/farmacología , Paclitaxel/uso terapéutico , Polietilenglicoles
18.
Front Bioeng Biotechnol ; 8: 595096, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33520954

RESUMEN

Native dental pulp extracellular matrix (DPEM) has proven to be an effective biomaterial for dental pulp regeneration. However, as a significant extracellular matrix glycoprotein, partial laminins were lost during the decellularization process, which were essential for odontoblast differentiation. Thereby, this study investigated the feasibility of LN supplementation to improve the surface of DPEM for odontoblast layer regeneration. The influences of laminin on cell adhesion and odontogenic differentiation were evaluated in vitro. Then, we fabricated laminin-modified DPEM based on the physical coating strategy and observed the location and persistency of laminin coating by immunofluorescent staining. Finally, laminin-modified DPEM combined with treated dentin matrix (TDM) was transplanted in orthotopic jaw bone of beagles (n = 3) to assess the effect of LNs on dental pulp tissue regeneration. The in vitro results showed that laminins could improve the adhesion of dental pulp stem cells (DPSCs) and promoted DPSCs toward odontogenic differentiation. Continuous odontoblastic layer-like structure was observed in laminin-modified DPEM group, expressing the markers for odontoblastogenesis, dentine matrix protein-1 (DMP-1) and dentin sialophosphoprotein (DSPP). Overall, these studies demonstrate that the supplementation of laminins to DPEM contributes to the odontogenic differentiation of cells and to the formation of odontoblast layer in dental pulp regeneration.

19.
J Appl Biomater Funct Mater ; 18: 2280800019836400, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33372827

RESUMEN

Magnesium alloys have been potential biodegradable implants in the areas of bone, cardiovascular system, gastrointestinal tract, and so on. The purpose of this study is to evaluate Mg-2Zn alloy degradation as a potential suture material. The study included Sprague-Dawley (SD) rats in vivo. In 24 male SD rats, tests in the leg muscle were conducted using traditional surgical incision and insertion of magnesium alloys of different designs into the tissue. The material degradation topography, elemental composition, and strength of the pins were analyzed. This paper explores magnesium pins with different cross-sectional shapes and diameters to establish a suitable pin diameter and shape for use as an oral stapler, which must have a good balance of degradation rate and strength. The results showed there were good bending strengths over different degradation periods in groups with diameters of 0.8 mm and 0.5 mm, and no significantly different bending strength between the groups of triangle and round cross-section shapes with same diameter of 0.3 mm, although the degradation rate still needs to be improved.


Asunto(s)
Implantes Absorbibles , Aleaciones/metabolismo , Aleaciones/química , Animales , Corrosión , Resistencia Flexional , Magnesio/química , Masculino , Ensayo de Materiales/métodos , Músculo Esquelético/metabolismo , Ratas , Ratas Sprague-Dawley , Propiedades de Superficie , Zinc/química
20.
Syst Appl Microbiol ; 43(5): 126104, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32847779

RESUMEN

Lignocellulose is considered a major source of renewable energy that serve as an alternative to the fossil fuels. Members of the genus Clostridium are some of the many microorganisms that have the ability to degrade lignocellulose efficiently to sugar, which can be further converted to biofuel. In this study, we isolated twelve Clostridium strains from hot spring samples of Yunnan and Tibet, of which isolates SYSU GA15002T and SYSU GA17076 showed low 16S rRNA gene sequence identity profiles to any of the validly named Clostridium strains (<94.0%). Studies using a polyphasic taxonomy approach concluded that the two isolates represent one novel species of the genus Clostridium, for which we propose the name Clostridium thermarum sp. nov., with SYSU GA15002T as the type strain of the species. Isolate SYSU GA15002T has an optimum growth temperature at 45°C. Fermentation of the substrates cellobiose, cellulose, xylan and untreated straw powder by this strain results in the production of ethanol, along with acetate and formate. The complete pathways for the conversion of cellulose and xylan to ethanol is also predicted from the genome of isolate SYSU GA15002T, which revealed a single step conversion of lignocellulosic biomass through consolidated bioprocessing. This paper is a comprehensive study encompassing isolation, polyphasic taxonomy, lignocellulose biodegradation and the genomic information of Clostridium in Yunnan-Tibet hot springs.


Asunto(s)
Clostridium/aislamiento & purificación , Clostridium/metabolismo , Etanol/metabolismo , Manantiales de Aguas Termales/microbiología , Lignina/metabolismo , Técnicas de Tipificación Bacteriana , Celobiosa/metabolismo , Celulosa/metabolismo , China , Clostridium/clasificación , Clostridium/genética , ADN Bacteriano/genética , Ácidos Grasos/análisis , Fermentación , Genes de ARNr , Genoma Bacteriano , Lípidos/análisis , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Tibet , Xilanos/metabolismo
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