RESUMO
BACKGROUND: Differentiating between low-grade glioma and brain glial cell hyperplasia is crucial for the customized clinical treatment of patients. OBJECTIVE: Based on multiparametric MRI imaging and clinical risk factors, a radiomics-clinical model and nomogram were constructed for the distinction of brain glial cell hyperplasia from low-grade glioma. METHODS: Patients with brain glial cell hyperplasia and low-grade glioma who underwent surgery at the First Affiliated Hospital of Soochow University from March 2016 to March 2022 were retrospectively included. In this study, A total of 41 patients of brain glial cell hyperplasia and 87 patients of low-grade glioma were divided into training group and validation group randomly at a ratio of 7:3. Radiomics features were extracted from T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), contrast-enhanced T1-weighted imaging (T1-enhanced). Then, LASSO, SVM, and RF models were created in order to choose a model with a greater level of efficiency for calculating each patient's Rad-score (radiomics score). The independent risk factors were identified via univariate and multivariate logistic regression analysis to filter the Rad-score and clinical risk variables in turn. A radiomics-clinical model was next built of which effectiveness was assessed. RESULTS: Brain glial cell hyperplasia and low-grade gliomas from the 128 cases were randomly divided into 10 groups, of which 7 served as training group and 3 as validation group. The mass effect and Rad-score were two independent risk variables used in the construction of the radiomics-clinical model, and their respective AUCs for the training group and validation group were 0.847 and 0.858. The diagnostic accuracy, sensitivity, and specificity of the validation group were 0.821, 0.750, and 0.852 respectively. CONCLUSION: Combining with radiomics constructed by multiparametric MRI images and clinical features, the radiomics-clinical model and nomogram that were developed to distinguish between brain glial cell hyperplasia and low-grade glioma had a good performance.
Assuntos
Glioma , Imageamento por Ressonância Magnética Multiparamétrica , Humanos , Hiperplasia , Estudos Retrospectivos , Neuroglia , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Diferenciação Celular , Glioma/diagnóstico por imagem , Glioma/cirurgiaRESUMO
BACKGROUND: Deep-sea mussels living in the cold seeps with enormous biomass act as the primary consumers. They are well adapted to the extreme environment where light is absent, and hydrogen sulfide, methane, and other hydrocarbon-rich fluid seepage occur. Despite previous studies on diversity, role, evolution, and symbiosis, the changing adaptation patterns during different developmental stages of the deep-sea mussels remain largely unknown. RESULTS: The deep-sea mussels (Bathymodiolus platifrons) of two developmental stages were collected from the cold seep during the ocean voyage. The gills, mantles, and adductor muscles of these mussels were used for the Illumina sequencing. A total of 135 Gb data were obtained, and subsequently, 46,376 unigenes were generated using de-novo assembly strategy. According to the gene expression analysis, amounts of genes were most actively expressed in the gills, especially genes involved in environmental information processing. Genes encoding Toll-like receptors and sulfate transporters were up-regulated in gills, indicating that the gill acts as both intermedium and protective screen in the deep-sea mussel. Lysosomal enzymes and solute carrier responsible for nutrients absorption were up-regulated in the older mussel, while genes related to toxin resistance and autophagy were up-regulated in the younger one, suggesting that the older mussel might be in a vigorous stage while the younger mussel was still paying efforts in survival and adaptation. CONCLUSIONS: In general, our study suggested that the adaptation capacity might be formed gradually during the development of deep-sea mussels, in which the gill and the symbionts play essential roles.
Assuntos
Mytilidae , Transcriptoma , Animais , Brânquias/metabolismo , Metano/metabolismo , SimbioseRESUMO
Objectives: To investigate the value of CT arterial enhancement fraction (AEF) in the post-processing technique of liver perfusion-like phase III enhanced CT scan in evaluating the degree of liver function impairment in patients with hepatitis B cirrhosis. Methods: The study included 85 patients with hepatitis B cirrhosis admitted to the Department of Radiology, The Affiliated Huai'an Hospital of Xuzhou Medical University from May 2018 to October 2020 were selected as the experimental group, and 71 patients with liver fibrosis during the same period were selected as the control group. All patients underwent routine liver CT phase III perfusion scan, and hepatic AEF (hAEF) and liver/spleen ratio (H/S) were compared between the two groups to analyze the differential value of hAEF and H/S for liver fibrosis and hepatitis B cirrhosis. Patients were divided into the mild group (Grade-A) and the severe group (Grade-B and C) according to Child-Pugh grading. hAEF and H/S values of the two groups were compared, and the evaluation value of AEF on the degree of impairment of hepatitis B cirrhosis was analyzed. Results: hAEF and H/S values of the experimental group were greater than those of the control group (P<0.05), and the AUCs of hAEF and H/S values for distinguishing hepatitis B and cirrhosis were 0.727 (95%CI: 0.650-0.795) and 0.791 (95%CI: 0.718-0.852), respectively. Moreover, hAEF and H/S values of the severe group were greater than those of the mild group (P<0.05), and the AUCs of hAEF and H/S values in evaluating the degree of liver function impairment were 0.746 (95%CI: 0.627-0.834) and 0.770 (95%CI: 0.705-0.928), respectively. Conclusions: AEF boasts the value of differentiating liver fibrosis and cirrhosis, and of evaluating the degree of liver function impairment in patients with hepatitis B cirrhosis.
RESUMO
As a powerful in situ detection technique, Raman spectroscopy is becoming a popular underwater investigation method, especially in deep-sea research. In this paper, an easy-to-operate underwater Raman system with a compact design and competitive sensitivity is introduced. All the components, including the optical module and the electronic module, were packaged in an L362 × Φ172 mm titanium capsule with a weight of 20 kg in the air (about 12 kg in water). By optimising the laser coupling mode and focusing lens parameters, a competitive sensitivity was achieved with the detection limit of SO42- being 0.7 mmol/L. The first sea trial was carried out with the aid of a 3000 m grade remotely operated vehicle (ROV) "FCV3000" in October 2018. Over 20,000 spectra were captured from the targets interested, including methane hydrate, clamshell in the area of cold seep, and bacterial mats around a hydrothermal vent, with a maximum depth of 1038 m. A Raman peak at 2592 cm-1 was found in the methane hydrate spectra, which revealed the presence of hydrogen sulfide in the seeping gas. In addition, we also found sulfur in the bacterial mats, confirming the involvement of micro-organisms in the sulfur cycle in the hydrothermal field. It is expected that the system can be developed as a universal deep-sea survey and detection equipment in the near future.
Assuntos
Fontes Hidrotermais , Bactérias , Metano , Análise Espectral RamanRESUMO
A Gram-stain-negative, aerobic, non-motile, rod-shaped bacterium, designated strain F15T, was isolated from a deep-sea sediment of the western Pacific Ocean. The temperature, pH and NaCl ranges for growth were 4-50 °C, pH 6-11 and 0-10 % (w/v), respectively. Strain F15T showed the highest 16S rRNA gene sequence similarity to Sagittula stellata E-37T (96.4%), followed by Ponticoccus litoralis CL-GR66T (96.4%), Antarctobacter heliothermus EL-219T (96.3%) and Thalassococcus lentus YCS-24T (96.0%). Phylogenetic analysis based on 16S rRNA gene sequence data showed that strain F15T formed a lineage within the family Rhodobacteraceae of the class Alphaproteobacteria. The polar lipid profile of strain F15T comprised significant amounts of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified glycolipid and one unidentified phospholipid. The predominant cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c, 40.2%), anteiso-C15 : 0 (30.4%) and anteiso-C17 : 0 (9.7%). The genomic DNA G+C content of strain F15T was 60.2âmol% and the major respiratory quinone was Q-10. On the basis of phenotypic, phylogenetic and chemotaxonomic data, strain F15T is considered to represent a novel species of a new genus within the family Rhodobacteraceae, for which the name Alkalimicrobium pacificum gen. nov., sp. nov. is proposed. The type strain is F15T ( = LMG 28107T = JCM 19851T = CGMCC 1.12763T = MCCC 1A09948T).
Assuntos
Sedimentos Geológicos/microbiologia , Filogenia , Rhodobacteraceae/classificação , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Dados de Sequência Molecular , Oceano Pacífico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Rhodobacteraceae/genética , Rhodobacteraceae/isolamento & purificação , Análise de Sequência de DNA , Ubiquinona/químicaRESUMO
Successful bioremediation of oil pollution is based on a comprehensive understanding of the in situ physicochemical conditions and indigenous microbial communities as well as the interaction between microorganisms and geochemical variables. Nineteen oil-contaminated soil samples and five uncontaminated controls were taken from six major oilfields across different geoclimatic regions in China to investigate the spatial distribution of the microbial ecosystem. Microbial community analysis revealed remarkable variation in microbial diversity between oil-contaminated soils taken from different oilfields. Canonical correspondence analysis (CCA) further demonstrated that a suite of in situ geochemical parameters, including soil moisture and sulfate concentrations, were among the factors that influenced the overall microbial community structure and composition. Phylogenetic analysis indicated that the vast majority of sequences were related to the genera Arthrobacter, Dietzia, Pseudomonas, Rhodococcus, and Marinobacter, many of which contain known oil-degrading or oil-emulsifying species. Remarkably, a number of archaeal genera including Halalkalicoccus, Natronomonas, Haloterrigena, and Natrinema were found in relatively high abundance in some of the oil-contaminated soil samples, indicating that these Euryarchaeota may play an important ecological role in some oil-contaminated soils. This study offers a direct and reliable reference of the diversity of the microbial community in various oil-contaminated soils and may influence strategies for in situ bioremediation of oil pollution.
Assuntos
Archaea/classificação , Bactérias/classificação , Biodegradação Ambiental , Biota , Campos de Petróleo e Gás , Poluição por Petróleo , Microbiologia do Solo , Archaea/genética , Archaea/isolamento & purificação , Bactérias/genética , Bactérias/isolamento & purificação , China , Análise por Conglomerados , DNA Arqueal/química , DNA Arqueal/genética , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Genes de RNAr , Dados de Sequência Molecular , RNA Arqueal/genética , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
A group of black shale samples, which were collected sequentially along a continuous depositional unit from bottom fresh zone toward the surface regolith of the weathering profile at Chengkou County, Southwest China, were examined using mineralogical, geochemical and pyrosequencing techniques. The mineralogical and geochemical analyses indicated that the black shale profile provided a series of extremely acidic and chemical species that changed microbial habitats following the process of weathering. This finding is in contrast with a previous hypothesis that a low-diversity bacterial community existed in these harsh environments; the pyrosequencing analyses showed extremely diverse microbial communities with 33 different phyla/groups in these samples. Among these phyla/groups, proteobacteria, actinobacteria and firmcutes were more dominant than other phyla, and the phylogenetic structures of the bacterial communities vary with the progressive process of weathering. Moreover, the canonical-correlation analysis suggested that pH and sulfur in sulfate, followed by total Fe and sulfur in pyrite, are the significant factors that shape the microbial community structure. In addition, a large proportion of S- and Fe-related bacteria, such as Acidithiobacillus, Sulfobacillus, Thiobacillus, Ferrimicrobium and Ferrithrix, may be responsible for pyrite bio-oxidation, as well as for S and Fe biogeochemical cycling, in the black shale weathering environments.
Assuntos
Bactérias/metabolismo , Ferro/metabolismo , Minerais/química , Enxofre/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biodiversidade , Ecossistema , Meio Ambiente , FilogeniaRESUMO
A Gram-stain negative, ovoid-rod shaped, strictly aerobic bacterium, strain Y2(T), was isolated from a deep-sea sediment of the Western Pacific. Phylogenetic and phenotypic properties of the organism indicated that it belongs to the genus Altererythrobacter. Strain Y2(T) shares highest 16S rRNA gene sequence similarity of 96.6 % with Erythrobacter jejuensis CNU001(T), followed by the type strains of recognized members of the genus Altererythrobacter (94.8-96.5 %). Strain Y2(T) forms a clade with E. jejuensis CNU001(T) in the cluster of species of the genus Altererythrobacter. Growth of strain Y2(T) was observed at 4-40 °C (optimum, 35-37 °C), at pH 6.0-10.0 (optimum, pH 7.0-8.0) and in the presence of 0-5 % (w/v) NaCl (optimum, 2-3 %). The major cellular fatty acids were found to be C17:1 ω6c (41.5 %), summed feature 8 (C18:1 ω7c and/or C18:1 ω6c; 17.2 %), C17:1 ω8c (11.0 %) and C15:0 2OH (8.1 %). The major respiratory quinone was determine to be ubiquinone 10 (Q-10). The polar lipid analysis indicated the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, one sphingoglycolipid, three unidentified phospholipids, two unidentified glycolipids, two unidentified aminolipids and three unknown lipids. The DNA G + C content of the type strain is 60.0 mol %. On the basis of the data from the polyphasic characterization, strain Y2(T) represents a novel species, for which the name Altererythrobacter oceanensis sp. nov. is proposed. The type strain is Y2(T) (=CGMCC 1.12752(T) =LMG 28109(T)).
Assuntos
Alphaproteobacteria/classificação , Alphaproteobacteria/isolamento & purificação , Sedimentos Geológicos/microbiologia , Aerobiose , Alphaproteobacteria/genética , Alphaproteobacteria/fisiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Análise por Conglomerados , Citosol/química , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Glicolipídeos/análise , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Oceano Pacífico , Fosfolipídeos/análise , Filogenia , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio/metabolismo , TemperaturaRESUMO
The Okinawa Trough (OT) is a back-arc basin with a wide distribution of active cold seep systems. However, our understanding of the metabolic function of microbial communities in the cold seep sediments of the OT remains limited. In this study, we investigated the vertical profiles of functional genes involved in methane, nitrogen, and sulphur cycling in the cold seep sediments of the OT. Furthermore, we explored the possible coupling mechanisms between these biogeochemical cycles. The study revealed that the majority of genes associated with the nitrogen and sulphur cycles were most abundant in the surface sediment layers. However, only the key genes responsible for sulphur disproportionation (sor), nitrogen fixation (nifDKH), and methane metabolism (mcrABG) were more prevalent within sulfate-methane transition zone (SMTZ). Significant positive correlations (P < 0.05) were observed between functional genes involved in sulphur oxidation, thiosulphate disproportionation with denitrification, and dissimilatory nitrate reduction to ammonium (DNRA), as well as between AOM/methanogenesis and nitrogen fixation, and between sulphur disproportionation and AOM. A genome of Filomicrobium (class Alphaproteobacteria) has demonstrated potential in chemoautotrophic activities, particularly in coupling DNRA and denitrification with sulphur oxidation. Additionally, the characterized sulfate reducers such as Syntrophobacterales have been found to be capable of utilizing nitrate as an electron acceptor. The predominant methanogenic/methanotrophic groups in the OT sediments were identified as H2-dependent methylotrophic methanogens (Methanomassiliicoccales and Methanofastidiosales) and ANME-1a. This study offered a thorough understanding of microbial ecosystems in the OT cold seep sediments, emphasizing their contribution to nutrient cycling.IMPORTANCEThe Okinawa Trough (OT) is a back-arc basin formed by extension within the continental lithosphere behind the Ryukyu Trench arc system. Cold seeps are widespread in the OT. While some studies have explored microbial communities in OT cold seep sediments, their metabolic potential remains largely unknown. In this study, we used metagenomic analysis to enhance comprehension of the microbial community's role in nutrient cycling and proposed hypotheses on the coupling process and mechanisms involved in biogeochemical cycles. It was revealed that multiple metabolic pathways can be performed by a single organism or microbes that interact with each other to carry out various biogeochemical cycling. This data set provided a genomic road map on microbial nutrient cycling in OT sediment microbial communities.
Assuntos
Archaea , Bactérias , Sedimentos Geológicos , Metano , Fixação de Nitrogênio , Nitrogênio , Enxofre , Metano/metabolismo , Sedimentos Geológicos/microbiologia , Enxofre/metabolismo , Nitrogênio/metabolismo , Bactérias/metabolismo , Bactérias/genética , Bactérias/classificação , Archaea/metabolismo , Archaea/genética , Archaea/classificação , Microbiota/genética , Água do Mar/microbiologia , Japão , FilogeniaRESUMO
Although coastal sediments are major contributors to the production of atmospheric methane, the effects of environmental conditions on methanogenesis and the community of methanogenic archaea are not well understood. Here, we investigated the methanogenesis pathways in nearshore and offshore sediments from the South Yellow Sea (SYS). Moreover, the effects of the supply of methanogenic substrates (H2/CO2, acetate, trimethylamine (TMA), and methanol) and temperature on methanogenesis and the community of methanogenic archaea were further determined. Methylotrophic, hydrogenotrophic and acetotrophic methanogenesis were found to be responsible for biogenic methane production in nearshore sediments. In the offshore sediments, methylotrophic methanogenesis was the predominant methanogenic pathway. The changes in methanogenic community structure under different substrate amendments were characterized. Lower diversities were detected in substrate-amended samples with methanogenic activity. Hydrogenotrophic Methanogenium, multitrophic Methanosarcina, methylotrophic Methanococcoide, Methanococcoide or methylotrophic Methanolobus were dominant in H2/CO2-, acetate-, TMA- and methanol-amended sediment slurries, respectively. PCoA showed that the methanogen community in H2/CO2 and acetate amendments exhibited greater differences than those in other treatments. Lower temperature (10 °C) limits hydrogenotrophic and acetoclastic methanogenesis, but methylotrophic methanogenesis is much less affected. The response of methanogen diversity to the incubation temperature varied among the different substrate-amended slurries. The multitrophic methanogen Methanosarcina became increasingly abundant in H2/CO2- and acetate-amended sediment slurries when the temperature increased from 10 to 30 °C.
Assuntos
Metano , Methanosarcinaceae , Archaea , Methanosarcina , TemperaturaRESUMO
Shallow methane/sulfate transition zones in cold seeps are hotspots to study microbially mediated geochemical cycles due to high methane fluxes. However, our knowledge about the microbial communities in remote seafloor cold seep ecosystems with different methane seepage intensity is still sparse due to the challenge for sampling and visual observations. In this work, three remotely operated vehicle (ROV) video-guided push sediment cores were sampled from cold seep fields with different methane seepage intensity (low-intensity seepage, R5-C1; moderate-intensity seepage, R6-C2; high-intensity seepage, R6-C3) at the western slope of Mid-Okinawa Trough (Mid-OT) and subjected to high throughput sequencing of 16S rRNA genes for bacteria and archaea. Vesicomyid clams and white microbial mats are visible by video at R6-C3 with methane bubbles. The high relative abundances of anaerobic methanotrophic archaea (ANME-1, -2, and -3), δ-Proteobacteriacea and Campylobacteria in R6-C3 indicated that the processes of anaerobic methane oxidation (AOM), sulfate reduction and sulfur oxidation might occur in this active seeping site. In contrast, Bathyarchaeia, Nitrosopumilales, Sphingomonadales, and Burkholderiales were enriched in bubble-free sites, which commonly involved in the degradation of organic compounds. Principal coordinate analysis showed that both bacterial and archaeal communities were clustered according to sampling sites, also indicating the impact of methane seepage intensity on microbial communities. The co-occurrence network analysis revealed that microbes at the site with high methane fluxes mainly cooperated with each other to sustain the ecosystems, whereas competition enhanced at sites with low methane fluxes. Detection of thermophiles Thermoanaerobaculia and Hydrothermarchaeota may indicate microbial transmission from nearby hydrothermal vents, suggesting potential interactions between cold seepage and hydrothermal vent ecosystems. These results expand our knowledge about the composition and distribution of bacteria and archaea with different methane seepage intensity in cold seep field at the Mid-OT, contributing to the ongoing efforts in understanding carbon cycling in the cold seep ecosystems.
Assuntos
Metano , Microbiota , Metano/metabolismo , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Sedimentos Geológicos/química , Filogenia , Archaea , Bactérias/metabolismo , Sulfatos/metabolismo , Oxirredução , Enxofre/metabolismo , Carbono/metabolismoRESUMO
Nowadays, vascular stents are commonly used to treat cardiovascular diseases. This article focuses on the influence of nitrogen doping of titanium dioxide thin films, utilized for coating metallic stents to improve their biological properties and biocompatibility. The hereby-investigated titanium oxide thin films are fabricated by magnetron sputtering in a reactive gas atmosphere consisting of argon and oxygen in the first case and argon, nitrogen and oxygen in the second case. Control of the nitrogen and oxygen gas flow rates, and hence their mixing ratios, allows adjustment of the nitrogen-doping level within the titanium dioxide thin films. A correlation of the thin film internal structure on the in vitro behavior of human mesenchymal stem cells derived from adipose tissue is hereby demonstrated. Different nitrogen doping levels affect the surface energy, the wettability, the cell adhesion and thus the cellular proliferation on top of the thin films. The surface colonization of cells on titanium dioxide thin films decreases up to a nitrogen-doping level of â¼ 3.75 at.%, which is associated with a decreasing polar component of the surface energy. For non-doped titanium dioxide thin films, a weak chondrogenesis of adult human adipose-derived mesenchymal stem cells with lower chondrogenic differentiation compared to glass is observed. An increasing nitrogen-doping level leads to linear increase in the chondrogenic differentiation rate, which is comparable to the control value of uncoated glass. Other investigated differentiated cell types do not display this behavior.
Assuntos
Dióxido de Nitrogênio , Titânio , Argônio , Humanos , Teste de Materiais , Nitrogênio/química , Oxigênio , Stents , Titânio/química , Titânio/farmacologiaRESUMO
Active cold seeps in the Okinawa Trough (OT) have been widely identified, but the sediment microbial communities associated with these sites are still poorly understood. Here, we investigated the distribution and biomass of the microbial communities, particularly those associated with the anaerobic oxidation of methane (AOM), in sediments from an active cold seep in the mid-Okinawa Trough. Methane-oxidizing archaea, including ANME-1a, ANME-1b, ANME-2a/b, ANME-2c, and ANME-3, were detected in the OT cold seep sediments. Vertical stratification of anaerobic methanotrophic archaea (ANME) communities was observed in the following order: ANME-3, ANME-1a, and ANME-1b. In addition, the abundance of methyl coenzyme M reductase A (mcrA) genes corresponded to high levels of dissolved iron, suggesting that methane-metabolizing archaea might participate in iron reduction coupled to methane oxidation (Fe-AOM) in the OT cold seep. Furthermore, the relative abundance of ANME-1a was strongly related to the concentration of dissolved iron, indicating that ANME-1a is a key microbial player for Fe-AOM in the OT cold seep sediments. Co-occurrence analysis revealed that methane-metabolizing microbial communities were mainly associated with heterotrophic microorganisms, such as JS1, Bathy-1, and Bathy-15.
RESUMO
Deep-sea mussels are widely distributed in marine chemosynthetic ecosystems. Bathymodiolus platifrons and B. japonicus, occurring at both cold seeps and hydrothermal vents, have been reported to house exclusively methanotrophic symbionts in the gill. However, the comparison of microbiota associated with different tissues between these two species from two contrasting habitats is still limited. In this study, using B. platifrons and B. japonicus collected from the adjacent cold seep and hydrothermal vent environments, we sampled different tissues (gill, adductor muscle, mantle, foot, and visceral mass including the gut) to decipher the microbial community structure at the tissue scale by employing 16S rRNA gene sequencing strategy. In the gill of both seep mussels and vent mussels, the symbiont gammaproteobacterial Methylomonaceae was the predominant lineage, and methane oxidation was identified as one of the most abundant putative function. In comparison, abundant families in other tissues were Pseudomonadaceae and Enterobacteriaceae in seep mussels and vent mussels, respectively, which may get involved in element cycling. The results revealed high similarity of community structure between two mussel species from the same habitat. The gill showed distinctive bacterial community structure compared with other tissues within the same environment, while the gill communities from two environments were more similar. Remarkably structural variations of adductor muscle, mantle, foot, and visceral mass were observed between two environments. This study can extend the understanding on the characteristics of tissue-associated microbiota of deep-sea mussels from the adjacent cold seep and hydrothermal vent environments.
Assuntos
Fontes Hidrotermais , Microbiota , Mytilidae , Animais , Bactérias/genética , Humanos , RNA Ribossômico 16S/genéticaRESUMO
In an effort to assess the potential contamination and determine the environmental risks associated with heavy metals, 51 surface sediment samples (0-4 cm) were collected in the Zhoushan Islands coastal sea of the East China Sea (ECS). The heavy metal concentrations, grain size and total organic carbon (TOC) contents of these surface sediments were comprehensively analyzed. The results showed that the order of the average concentrations of heavy metals is Zn > Cr > Cu > Pb > As > Cd > Hg. Zn, Cr, Cd and Hg exhibit similar distribution and which derived from a common source, however, Cu, Pb and As present different distribution. The metal enrichment factor (EF) and geoaccumulation index (Igeo) values both suggest that Cu and Cd likely pose environmental risks. The results of this study could provide scientific data to authorities in charge of sustainable marine management.
Assuntos
Metais Pesados , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos , Ilhas , Metais Pesados/análise , Medição de Risco , Poluentes Químicos da Água/análiseRESUMO
Cardiovascular diseases are the most distributed cause of death worldwide. Stenting of arteries as a percutaneous transluminal angioplasty procedure became a promising minimally invasive therapy based on re-opening narrowed arteries by stent insertion. In order to improve and optimize this method, many research groups are focusing on designing new or improving existent stents. Since the beginning of the stent development in 1986, starting with bare-metal stents (BMS), these devices have been continuously enhanced by applying new materials, developing stent coatings based on inorganic and organic compounds including drugs, nanoparticles or biological components such as genes and cells, as well as adapting stent designs with different fabrication technologies. Drug eluting stents (DES) have been developed to overcome the main shortcomings of BMS or coated stents. Coatings are mainly applied to control biocompatibility, degradation rate, protein adsorption, and allow adequate endothelialization in order to ensure better clinical outcome of BMS, reducing restenosis and thrombosis. As coating materials (i) organic polymers: polyurethanes, poly(ε-caprolactone), styrene-b-isobutylene-b-styrene, polyhydroxybutyrates, poly(lactide-co-glycolide), and phosphoryl choline; (ii) biological components: vascular endothelial growth factor (VEGF) and anti-CD34 antibody and (iii) inorganic coatings: noble metals, wide class of oxides, nitrides, silicide and carbide, hydroxyapatite, diamond-like carbon, and others are used. DES were developed to reduce the tissue hyperplasia and in-stent restenosis utilizing antiproliferative substances like paclitaxel, limus (siro-, zotaro-, evero-, bio-, amphi-, tacro-limus), ABT-578, tyrphostin AGL-2043, genes, etc. The innovative solutions aim at overcoming the main limitations of the stent technology, such as in-stent restenosis and stent thrombosis, while maintaining the prime requirements on biocompatibility, biodegradability, and mechanical behavior. This paper provides an overview of the existing stent types, their functionality, materials, and manufacturing conditions demonstrating the still huge potential for the development of promising stent solutions.
RESUMO
Selected trace elements (As, Cr, Zn, Cu, Cd, Co, Pb and Ni) in 76 surface sediment samples collected from the rivers and the intertidal zone of Jiaozhou Bay (JZB) were evaluated to assess their environmental background values in the JZB catchment. Overall, the sediment quality in the area meets the China Marine Sediment Quality criteria. The background values (ranges) of the elements As, Cr, Zn, Cu, Cd, Co, Pb and Ni were, respectively, 8.28 (4.10-12.46), 67.96 (38.40-97.52), 56.80 (16.42-196.51), 19.13 (5.71-64.06), 0.10 (0.02-0.42), 6.51 (2.08-20.40), 17.97 (12.26-55.84) and 20.69 (10.43-30.95)mg/kg. The background values of most of the trace elements were lower than those in Chinese soil, the upper continental crust, global shales and global preindustrial sediments. The results may assist in defining future coastal and river management measures specifically targeted at monitoring trace element contamination in the JZB catchment.
Assuntos
Oligoelementos/análise , Poluentes Químicos da Água/análise , Baías , China , Monitoramento Ambiental , Sedimentos Geológicos , Metais Pesados , RiosRESUMO
White semi-consolidated carbonate sediments attached to black ferromanganese oxide films were collected approximately 50 km west of a newly discovered hydrothermal field near the Southwest Indian Ridge (SWIR). The biodiversity of the prokaryotic communities within the field was examined using clone library-based culture-independent analysis of the exterior black oxides and the interior white carbonates. Subsequent 16S rRNA gene analysis suggested that Gamma-proteobacteria, Acidobacteria, and Thaumarchaeota members dominated the bacterial and archaeal clone libraries. To further characterize the metabolic processes within the microbial community, analyses of the amoA (coding the alpha subunit of the ammonia monooxygenase for Archaea) and aprA (coding the alpha subunit of the dissimilatory adenosine-5'-phosphosulfate reductase for the sulfate-reducing and sulfur-oxidizing prokaryotes) functional genes were conducted. The functional gene analysis results suggested that Thaumarchaeota and Alphaproteobacteria members were the potential players that participated in N and S cycles in this marine carbonate sedimentary environment. This paper is the first to describe the microbial communities and their potential metabolic pathways within the semi-consolidated carbonate sediments of the SWIR.
Assuntos
Archaea , Sedimentos Geológicos/microbiologia , Archaea/classificação , Archaea/genética , Archaea/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , DNA Arqueal/genética , DNA Bacteriano/genética , Oceano Índico , Microbiota , RNA Ribossômico 16SRESUMO
Distribution of methane in surface water and sediment of Jiulongjiang Estuary was investigated during July, 2009 through head-space method. The concentration of methane varies from 10.7 to 456.7 nmol x L(-1) in the surface water at 56 sampled stations, and supersaturates relative to equilibrium with atmospheric methane. The concentration of methane decreases rapidly from estuarine upside margin to the open coastal ocean, resulting from mixing between high CH4-containing fresh water and low CH4-containing seawater. The sediment cores are situated in the upper estuarine coast and seaward boundary along the estuarine salinity gradient, representing the freshwater, half-brackish and marine water environment. Distribution of methane in porewater is consistent with that of surface water, which decreases rapidly from B1, B2, B3 to B4 stations, from 2 212 micromol x L(-1) to 5 micromol x L(-1). The concentration of sulfate in porewater increases gradually from B1, B2, B3 to B4 stations, with average value of 0.13, 0.64, 5.3 and 16.3 mmol x L(-1) respectively. The trends of methane in surface water and porewater have illustrated a large amount of methane is generated via the process of organic matter degradation mediated by methanogens, moved across sediment-water interface, and entered to overlying water. In seaward boundary sediment with an abundance of sulphate in sediment, and sulphate in porewater inhibits the methanogenesis, the methane input from the sediment rapidly decreases. Depth profiles of methane in porewater B2 and B3 stations show an increase in concentration from 43 and 10 micromol x L(-1) near the sediment-water interface to about 1 051 and 57 micromol L(-1) at core end. According to the vertical profile of methane, total organic carbon (TOC) and sulfate trend, a large amount of methane is depleted via anoxic oxidation in methane-sulfate transition. The methane released from the low concentration of sulfate sediment intertidal wetland situated in upper estuarine could be the most important source in Jiulongjiang estuary.