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Cobalamin (vitamin B12, herein referred to as B12) is an essential cofactor for most marine prokaryotes and eukaryotes1,2. Synthesized by a limited number of prokaryotes, its scarcity affects microbial interactions and community dynamics2-4. Here we show that two bacterial B12 auxotrophs can salvage different B12 building blocks and cooperate to synthesize B12. A Colwellia sp. synthesizes and releases the activated lower ligand α-ribazole, which is used by another B12 auxotroph, a Roseovarius sp., to produce the corrin ring and synthesize B12. Release of B12 by Roseovarius sp. happens only in co-culture with Colwellia sp. and only coincidently with the induction of a prophage encoded in Roseovarius sp. Subsequent growth of Colwellia sp. in these conditions may be due to the provision of B12 by lysed cells of Roseovarius sp. Further evidence is required to support a causative role for prophage induction in the release of B12. These complex microbial interactions of ligand cross-feeding and joint B12 biosynthesis seem to be widespread in marine pelagic ecosystems. In the western and northern tropical Atlantic Ocean, bacteria predicted to be capable of salvaging cobinamide and synthesizing only the activated lower ligand outnumber B12 producers. These findings add new players to our understanding of B12 supply to auxotrophic microorganisms in the ocean and possibly in other ecosystems.
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Alteromonadaceae , Ligantes , Rhodobacteraceae , Vitamina B 12 , Oceano Atlântico , Técnicas de Cocultura , Interações Microbianas , Prófagos/genética , Prófagos/crescimento & desenvolvimento , Prófagos/metabolismo , Vitamina B 12/biossíntese , Vitamina B 12/química , Vitamina B 12/metabolismo , Alteromonadaceae/crescimento & desenvolvimento , Alteromonadaceae/metabolismo , Rhodobacteraceae/citologia , Rhodobacteraceae/metabolismo , Rhodobacteraceae/virologia , Ribonucleosídeos/metabolismo , Cobamidas/metabolismo , EcossistemaRESUMO
The potential to produce and release outer membrane vesicles (OMVs) is evolutionarily conserved among bacteria, facilitating interactions between microbes. OMV release and its ecological significance have rarely been reported in coral holobionts. Here, via transmission electron microscopy (TEM), we discovered that the coral-associated strain Vibrio coralliilyticus DSM 19607 produced OMVs in culture. OMVs purified from V. coralliilyticus DSM 19607 inhibited the bacteriophage (phage) SBM1 infection of the V. coralliilyticus host, which was impaired by elevated temperature. Observation via TEM showed that sequestrating phages was a potential approach for V. coralliilyticus OMVs protection against phage infection. Furthermore, detection in coral mucus showed that interactions between membrane vesicles and phages potentially occurred in the natural environment. These results imply that OMVs regulate the coral microbiome and may have important implications for our mechanistic understanding of coral health and disease in the face of climate change.
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Antozoários , Bacteriófagos , Vibrio , Animais , Antozoários/microbiologiaRESUMO
Alginate hydrogel is highly efficient for water filtration due to its anti-fouling nature and formation of strong hydration membranes. However, poor mechanical properties of alginate hydrogel membrane limit its installation in water treatment. There is a need to enhance mechanical properties of alginate hydrogel membranes using eco-friendly, cost-effective materials and technologies. In this work, hydroentangled non-woven from cotton waste (comber noil) fibers was prepared. This non-woven was immersed in solution of sodium alginate (0.5 %, 1 %, 1.5 %) followed by dipping in calcium chloride solution which resulted in gel formation on and into cotton fibers. The successful formation of gel on non-woven fabric was confirmed through FTIR (Fourier transform infrared spectroscopy) and properties of this composite membrane were analyzed by SEM (Scanning electron microscopy), XRD (X-ray diffraction), DSC (Differential scanning calorimeter), water contact, water flux, oil-water filtration, air permeability, tensile strength, and porosity tests. The results showed that porosity of prepared hydrogel membranes decreased with increasing alginate concentration from 0.5 % to 1.5 % which resulted in decreased water permeation flux from 2655 h-1/m2 to 475 h-1/m2. The prepared membrane has separation efficiencies for the oil-water mixture in the range of 97.5 % to 99.5 %. Moreover, the developed samples also showed significant antibacterial activity as well as improved mechanical properties. The strength of the prepared membrane is in the range of 40 N to 80 N. The developed sodium alginate hydrogel-based non-woven membrane could have potential applications for commercial water filtration systems.
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Alginatos , Hidrogéis , Hidrogéis/química , Alginatos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Cloreto de Cálcio , AntibacterianosRESUMO
IMPORTANCE: As the major producers and consumers, phytoplankton and bacteria play central roles in marine ecosystems and their interactions show great ecological significance. Whether mutualistic or antagonistic, the interaction between certain phytoplankton and bacterial species is usually seen as a derivative of intrinsic physiological properties and rarely changes. This study demonstrated that the interactions between the ubiquitously co-occurring bacteria and diatom, Alteromonas and Thalassiosira pseudonana, varied with nutrient conditions. They overcame hardship together in oligotrophic seawater but showed antagonistic effects against each other under nutrient amendment. The contact-dependent algicidal behavior of Alteromonas based on protease activity solved the paradox among bacterial proliferation, nutrient viability, and algal demise haunting other known non-contact-dependent algicidal processes and might actually trigger the collapse of algal blooms in situ. The chemotactic and swarming movement of Alteromonas might also contribute greatly to the breakdown of "marine snow," which could redirect the carbon sequestration pathway in the ocean.
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Alteromonas , Diatomáceas , Diatomáceas/metabolismo , Ecossistema , Fitoplâncton , Água do Mar/microbiologia , BactériasRESUMO
Hydrogels which become increasingly important in the biomedical field are composed of a three-dimensional hydrophilic network. Pure hydrogels are usually weak and brittle; therefore, reinforcements are assimilated into the hydrogel structure to improve the mechanical strength of the hydrogels. However, even if mechanical properties are enhanced, drapability remains an issue. In that regard, natural fiber-reinforced composite hydrogel fibers for wound dressing application are investigated in this study. Kapok and hemp fibers were used as reinforcement to improve the strength of hydrogel fibers. The properties of the prepared composite hydrogel fibers were studied with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimeter (DSC). The effect of alginate concentration and fiber weight percent on the mechanical characteristics and water absorbency was studied. Diclofenac sodium drug was loaded in the hydrogel fibers and investigated the drug release as well as antibacterial characteristics. Both fibers' reinforcement enhanced the strength of the alginate hydrogel fiber, but hemp reinforcement showed better mechanical properties. Kapok reinforcement resulted in a maximum tensile strength of 174 cN (1.24 % elongation) and 432 % exudate absorbency, while hemp reinforcement resulted in 185 cN (1.48 % elongation) and 435 % exudate absorbency. Statistical analysis revealed significant effects of sodium alginate concentration on tensile strength (p-value 0.042) and exudate absorbency (p-value 0.020) and of reinforcement (wt%) on exudate absorbency (p-value 0.043). Therefore, these composite hydrogel fibers with improved mechanical properties are capable of drug release and exhibit antibacterial effectiveness, making them a promising option for use as wound dressings.
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Diclofenaco , Hidrogéis , Hidrogéis/química , Diclofenaco/farmacologia , Alginatos/química , Cicatrização , Bandagens , Antibacterianos/farmacologiaRESUMO
In Pakistan, substantial changes to hepatitis C virus (HCV) programming and treatment have occurred since the 2008 nationwide serosurvey estimated a 4.8% anti-HCV prevalence. In the absence of an updated national study, this analysis uses provincial data to estimate a national prevalence and the interventions needed to achieve elimination. Using a Delphi process, epidemiologic HCV data for the four provinces of Pakistan (accounting for 97% of the population) were reviewed with 21 subject-matter experts in Pakistan. Province-level estimates were inputted into a mathematical model to estimate the national HCV disease burden in the absence of intervention (Base), and if the World Health Organization (WHO) elimination targets are achieved by 2030 (80% reduction in new infections, 90% diagnosis coverage, 80% treatment coverage, and 65% reduction in mortality: WHO Elimination). An estimated 9,746,000 (7,573,000-10,006,000) Pakistanis were living with viraemic HCV as of January 1, 2021; a viraemic prevalence of 4.3% (3.3-4.4). WHO Elimination would require an annual average of 18.8 million screens, 1.1 million treatments, and 46,700 new infections prevented anually between 2022 and 2030. Elimination would reduce total infections by 7,045,000, save 152,000 lives and prevent 104,000 incident cases of hepatocellular carcinoma from 2015 to 2030. Blood surveys, programmatic data, and expert panel input uncovered more HCV infections and lower treatment numbers in the provinces than estimated using national extrapolations, demonstrating the benefits of a bottom-up approach. Screening and treatment must increase 20 times and 5 times, respectively, to curb the HCV epidemic in Pakistan and achieve elimination by 2030.
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Hepatite C , Neoplasias Hepáticas , Humanos , Hepacivirus , Prevalência , Paquistão/epidemiologia , Antivirais/uso terapêutico , Hepatite C/epidemiologia , Neoplasias Hepáticas/tratamento farmacológicoRESUMO
Objective: Through this study, we sought to evaluate the management of posterior fossa extradural hematoma (PFEDH). Methods: An observational study was conducted at the Neurosurgery Department of Lady Reading Hospital in Peshawar from January 2015 to December 2020. All patients who had a traumatic acute extradural hematoma (EDH) of the posterior fossa were included, irrespective of age and gender. The clinical predictors and outcomes were assessed, including the CT-scan findings and Glasgow Coma Scale (GCS) score. Results: A total of 104 cases with posterior fossa extradural hematoma were identified from 1252 extradural hematoma patients admitted during the study period. The mean age of the enrolled patients was 18.17 ± 14.31 years. Most of the patients were male (65.39%) and belonged to the pediatric age group, i.e., < 15 years (60.6%). CT scan brain was done in all the cases for diagnosis. In 68.3% of cases, an associated occipital bone fracture was observed. Surgery was done in almost 71.2% of cases, and most of the patients experienced good recovery after surgery, as indicated by the GOS score. Linear regression model revealed that treatment (ß=-0.20, p=0.038), time duration between surgery and trauma (ß=0.43, p=0.000) and GCS category (ß=-0.47, p=0.000) were significantly associated with PFEDH outcomes. Conclusion: In conclusion, PFEDH was frequent among males and the pediatric age group. Serial CT brain is highly recommended in all suspected cases for early diagnosis.
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In this study, cotton-reinforced alginate hydrogel fibers were successfully synthesized using the wet spinning technique to improve hydrogel fibers' mechanical strength and durability. Structural, chemical, and mechanical properties of the prepared fibers were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray Diffraction, differential scanning calorimeter, and single fiber strength tester. Based on the results obtained from fourier transform infrared spectroscopy and x-ray Diffraction, cotton fibers have been successfully incorporated into the structure of the hydrogel fibers. It was seen from the differential scanning calorimeter results that the incorporation of fibers in the structure even enhanced the thermal stability of the fiber and is viable to be implanted in the human body. Cotton reinforcement in alginate hydrogel fibers increases the modulus up to 56.45 MPa providing significant stiffness and toughness for the hydrogel composite fiber. The tenacity of the fibers increased by increasing the concentration of alginate from 2.1 cN/Tex (1% w/v) to 8.16 cN/Tex (1.5% w/v). Fiber strength increased by 26.75% and water absorbance increased by 120% by incorporating (10% w/w) cotton fibers into the fibrous structure. It was concluded that these cotton-reinforced alginate hydrogel fibers have improved mechanical properties and liquid absorption properties suitable for use in various biomedical applications.
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The exchange of metabolites mediates algal and bacterial interactions that maintain ecosystem function. Yet, while thousands of metabolites are produced, only a few molecules have been identified in these associations. Using the ubiquitous microalgae Pseudo-nitzschia sp., as a model, we employed an untargeted metabolomics strategy to assign structural characteristics to the metabolites that distinguished specific diatom-microbiome associations. We cultured five species of Pseudo-nitzschia, including two species that produced the toxin domoic acid, and examined their microbiomes and metabolomes. A total of 4826 molecular features were detected by tandem mass spectrometry. Only 229 of these could be annotated using available mass spectral libraries, but by applying new in silico annotation tools, characterization was expanded to 2710 features. The metabolomes of the Pseudo-nitzschia-microbiome associations were distinct and distinguished by structurally diverse nitrogen compounds, ranging from simple amines and amides to cyclic compounds such as imidazoles, pyrrolidines and lactams. By illuminating the dark metabolomes, this study expands our capacity to discover new chemical targets that facilitate microbial partnerships and uncovers the chemical diversity that underpins algae-bacteria interactions.
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Diatomáceas , Microbiota , Diatomáceas/metabolismo , Espectrometria de Massas em Tandem , MetabolomaRESUMO
Colloidal particles constitute a substantial fraction of organic matter in the global ocean and an abundant component of the organic matter interacting with bacterial surfaces. Using E. coli ribosomes as model colloidal particles, we applied high-resolution atomic force microscopy to probe bacterial surface interactions with organic colloids to investigate particle attachment and relevant surface features. We observed the formation of ribosome films associating with marine bacteria isolates and natural seawater assemblages, and that bacteria readily utilized the added ribosomes as growth substrate. In exposure experiments ribosomes directly attached onto bacterial surfaces as 40-200 nm clusters and patches of individual particles. We found that certain bacterial cells expressed surface corrugations that range from 50-100 nm in size, and 20 nm deep. Furthermore, our AFM studies revealed surface pits in select bacteria that range between 50-300 nm in width, and 10-50 nm in depth. Our findings suggest novel adaptive strategies of pelagic marine bacteria for colloid capture and utilization as nutrients, as well as storage as nanoscale hotspots of DOM.
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Coloides , Escherichia coli , Bactérias , Oceanos e Mares , Água do MarRESUMO
OBJECTIVES: To determine the success rate and complications of primary endoscopic third ventri-culostomy (ETV) in infants with obstructive hydrocephalous. METHODS: This case series was conducted at the Department of Neurosurgery, Medical and Teaching Institute, Lady Reading Hospital Peshawar from July 2016 to June 2018. All consecutive patients with age less than one year who underwent ETV for primary obstructive hydrocephalous, of both gender, were included in the study. The patients were followed up to six months after surgery. The data was entered in a specially designed Performa. Patients' data was analyzed using SPSS version 21.0. RESULTS: We had total 21 patients with age less than one year during the study period. Male patients were 11 (52.4%). Success rate of ETV at six months of follow up was 12 (57.1%). Post-op complications observed were in 9.52% (2/21) cases. One patient had cerebrospinal fluid CSF) leak and the other had significant bleed. CONCLUSION: ETV is successful in 57.1% of infants with obstructive type of hydrocephalous. The post op complications in case of ETV are lower than Ventriculo-peritoneal shunts. Therefore, ETV can be offered to infants having obstructive hydrocephalous.
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Microbial degradation of dissolved organic carbon (DOC) in aquatic environments can cause oxygen depletion, water acidification, and CO2 emissions. These problems are caused by labile DOC (LDOC) and not refractory DOC (RDOC) that resists degradation and is thus a carbon sink. For nearly a century, chemical oxygen demand (COD) has been widely used for assessment of organic pollution in aquatic systems. Here, we show through a multicountry survey and experimental studies that COD is not an appropriate proxy of microbial degradability of organic matter because it oxidizes both LDOC and RDOC, and the latter contributes up to 90% of DOC in high-latitude forested areas. Hence, COD measurements do not provide appropriate scientific information on organic pollution in natural waters and can mislead environmental policies. We propose the replacement of the COD method with an optode-based biological oxygen demand method to accurately and efficiently assess organic pollution in natural aquatic environments.
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OBJECTIVE: To evaluate the outcomes of modified interlaminar decompression in patients with degenerative lumbar spinal stenosis (LSS). METHODS: This descriptive observational study was conducted at the Department of Neurosurgery, Lady Reading Hospital Peshawar from July 2014 to June 2018. All patients with degenerative LSS who underwent modified interlaminar decompression during the study period were included in the study. The patients were followed up to one year after surgery. The data was entered into a structured questionnaire designed according to the study which was then analyzed using SPSS version 21. RESULTS: A total of 182 LSS cases were included in the study and 236 levels were operated during the study period. According to the records increased prevalence of LSS was found among males i.e. 58.8%. The common level with degenerative stenosis involved was L4-5. Good to excellent outcomes were observed in 93.9% patients in the 1st follow-up visit. The most common complication of surgery was dural tear followed by wound infection. CONCLUSION: Modified interlaminar decompression is a conservative surgical technique, proved to be a potential approach with acceptable complications, satisfactory outcomes and it is easy to learn.
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Corals have evolved as optimized photon augmentation systems, leading to space-efficient microalgal growth and outstanding photosynthetic quantum efficiencies. Light attenuation due to algal self-shading is a key limiting factor for the upscaling of microalgal cultivation. Coral-inspired light management systems could overcome this limitation and facilitate scalable bioenergy and bioproduct generation. Here, we develop 3D printed bionic corals capable of growing microalgae with high spatial cell densities of up to 109 cells mL-1. The hybrid photosynthetic biomaterials are produced with a 3D bioprinting platform which mimics morphological features of living coral tissue and the underlying skeleton with micron resolution, including their optical and mechanical properties. The programmable synthetic microenvironment thus allows for replicating both structural and functional traits of the coral-algal symbiosis. Our work defines a class of bionic materials that is capable of interacting with living organisms and can be exploited for applied coral reef research and photobioreactor design.
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Antozoários/fisiologia , Biônica/métodos , Recifes de Corais , Microalgas/fisiologia , Animais , Antozoários/efeitos da radiação , Conservação dos Recursos Naturais/métodos , Ecossistema , Luz , Microalgas/efeitos da radiação , Fotossíntese/efeitos da radiação , Impressão Tridimensional , Simbiose/efeitos da radiaçãoRESUMO
We aim to present here a small case series of symptomatic isolated hemorrhagic arterialized developmental venous anomalies (sDVAs) with a larger goal of revisiting the classification based on patho-mechanisms plus emphasizing angiographic features coupled with CT and MRI. Typically, DVA is an incidental and silent abnormality on neuroimaging. Understanding its morphology in terms of arterialization and relationship with other entities is crucial for management. One adult and two pediatric cases presented with acute or sub-acute hemorrhage in the cerebellum or thalamus. Morphologic characterization on cross-sectional imaging and catheter angiography confirmed the integrated diagnosis of "symptomatic isolated hemorrhagic arterialized DVAs with deeper or superficial venous drainage". Conservative management was adopted in all cases. We emphasize the following classification and approach for symptomatic DVAs: (1) congestive isolated arterialized sDVAs, (2) congestive isolated resistive sDVAs, (3) coexisting sDVAs (with AVM or cavernous malformation), (4) compressive sDVAs (compressive effects), and (5) idiopathic DVAs. Like our three cases, ganglionic and infratentorial DVAs have higher propensity of hemorrhage, compressive effects, and usually harbor deeper venous drainage. Typical "caput medusae" as dominant collector vein on cross-sectional imaging is crucial to complement and even confirm the diagnosis of DVA before catheter angiography in sDVAs. Capillary stain or early opacification of DVAs is a marker of arteriovenous shunting in arterialized sDVAs. Recognition of this entity is crucial as treatment is usually conservative.
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Veias Cerebrais , Imageamento por Ressonância Magnética , Adulto , Cerebelo , Criança , Hemorragia , Humanos , Procedimentos NeurocirúrgicosRESUMO
The type VI secretion system (T6SS) is a nanomachine capable of killing adjacent microbial cells in a contact-dependent manner. Due to limited studies, relatively little is known about the range of marine bacteria that are susceptible to T6SS attack. Here, 15 diverse marine bacterial isolates from the phyla Bacteroidetes and Æ-Proteobacteria were challenged against the marine bacterium and human pathogen, Vibrio cholerae, which has a well described T6SS. V. cholerae killed several of the tested Æ-Proteobacteria, including members of the orders Vibrionales, Alteromonadales, Oceanospirillales, and Pseudomonadales. In contrast, V. cholerae co-existed with multiple Bacteroidetes and Æ-Proteobacteria isolates, but was killed by Vibrio coralliilyticus. Follow-up experiments revealed that five V. coralliilyticus strains, including known coral and shellfish pathogens survived the T6SS challenge and killed V. cholerae. By using predicted protein comparisons and mutagenesis, we conclude that V. coralliilyticus protected itself in the challenge by using its own T6SS to kill V. cholerae. This study provides valuable insight into the resilience and susceptibility of marine bacteria to the V. cholerae T6SS, and provides the first evidence for a functional T6SS in V. coralliilyticus, both of which have implications for human and ocean health.
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Sistemas de Secreção Tipo VI/genética , Vibrio cholerae/patogenicidade , Vibrio/genética , Animais , Antozoários/microbiologia , Anticorpos Antibacterianos/genética , Proteínas de Bactérias/genética , Bacteroidetes/genética , Regulação Bacteriana da Expressão Gênica/genética , Proteobactérias/genética , Frutos do Mar/microbiologia , Vibrio cholerae/genéticaRESUMO
Viruses influence microbial community structure and biogeochemical cycles in marine environments. Viral attachment to nonhost surfaces could influence host viral infection rates; however, the prevalence of such viral attachment is not investigated quantitatively. We used coastal seawater viral assemblages and, as models, marine vibriophage (SIO-2) and enterobacteriophages (T2 and T4) to investigate their attachment to probable nonhost marine bacteria. We also studied viral attachment to colloids and other abiotic surfaces in seawater. Centrifugation experiments with bacterium-virus mixtures showed substantial viral loss in the supernatant presumably due to the viral attachment to bacteria. This attachment (0.04 to 24 viruses µm-2 [bacterial surface area]) varied with bacterium-virus combinations. Surprisingly, filtering seawater on 0.2-µm Anodisc or polycarbonate filters retained â¼12 to 84% of viruses presumably attached to ≥0.2-µm-sized particles and/or the filter surface. Enzymatic digestion followed by epifluorescence and atomic force microscopy suggested that 7 to 25% of the total viruses were attached via ß-glycosidic linkages. Furthermore, a substantial proportion (7 to 48%) of viruses became attached to model abiotic surfaces (polycarbonate, polypropylene, and glass), and this has significance for laboratory protocols as well as studies of virus ecology in particle-rich marine environments. Substantial attachment of viruses to nonhost surfaces could influence virus-driven biogeochemical cycles and microbial community structure.IMPORTANCE Viruses play important roles in altering microbial community structure and biogeochemical cycles in marine environments. Viral attachment to nonhost surfaces can influence host viral infection rates; however, the prevalence of viral attachment to nonhost surfaces and the ratio of attached viruses to total viruses are little known. We used coastal seawater viral assemblages and used marine vibriophage (SIO-2) and enterobacteriophages (T2 and T4) as models to investigate their attachment to abiotic and biotic surfaces in seawater. Viral attachment was observed on several surfaces, such as nonhost bacteria, polymers, filters, cover glasses, and tube surfaces. This study cautions against commonly used protocols that require viral incubation and seawater fractionation. More importantly, these results could influence virus-driven biogeochemical cycles and microbial community structure in the ocean.
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Bacteriófagos/isolamento & purificação , Microbiota , Água do Mar/virologia , Ligação Viral , ColoidesRESUMO
This study evaluates the antioxidant activity of Ranunculus muricatus and isolation and structure elucidation of the active constituents. The aerial parts of the plants were shade dried at room temperature and powdered and extracted with methanol. The free radical scavenging activity was evaluated by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay. The percentage scavenging activity was determined based on the percentage of DPPH radical scavenged. Column chromatography was used in order to isolate the active compounds. Spectral techniques UV, IR, 1H NMR, 13CNMR and HREI-MS were used for the structure elucidation of the isolated compounds. Two isolated compounds, A (caffeoyl-ß-D-glucopyranoside) and B (1,3-dihydroxy-2-tetracosanoylamino-4-(E)-nonadecene), exibited a significant antioxidant activity as showed by DPPH radical scavenging method. Percentage inhibition for compound A (at 0.5 mM) was 82.67 ± 0.19 with IC50 of 93.25 ± 0.12 (µM), and for compound B (at 0.5 mM) was 69.23 ± 0.19 with IC50 of 183.34 ± 0.13 (µM). Quercetin was used as standard control. It was conclued from the present study that caffeoyl-ß-D-glucopyranoside and 1,3-dihydroxy-2-tetracosanoylamino-4-(E)-nonadecene isolated from methanol extract of aerial parts of Ranunculus muricatus posses antioxidant activity.
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Ácidos Cafeicos/química , Ácidos Cafeicos/isolamento & purificação , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/isolamento & purificação , Glucosídeos/química , Glucosídeos/isolamento & purificação , Ranunculus/química , Compostos de Bifenilo/química , Picratos/químicaRESUMO
In the Anthropocene, in which we now live, climate change is impacting most life on Earth. Microorganisms support the existence of all higher trophic life forms. To understand how humans and other life forms on Earth (including those we are yet to discover) can withstand anthropogenic climate change, it is vital to incorporate knowledge of the microbial 'unseen majority'. We must learn not just how microorganisms affect climate change (including production and consumption of greenhouse gases) but also how they will be affected by climate change and other human activities. This Consensus Statement documents the central role and global importance of microorganisms in climate change biology. It also puts humanity on notice that the impact of climate change will depend heavily on responses of microorganisms, which are essential for achieving an environmentally sustainable future.
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Mudança Climática , Ecossistema , Gases de Efeito Estufa/metabolismo , Atividades Humanas , Viabilidade Microbiana/efeitos da radiação , HumanosRESUMO
Nanoscale multipoint structure-function analysis is essential for deciphering the complexity of multiscale biological and physical systems. Atomic force microscopy (AFM) allows nanoscale structure-function imaging in various operating environments and can be integrated seamlessly with disparate probe-based sensing and manipulation technologies. Conventional AFMs only permit sequential single-point analysis; widespread adoption of array AFMs for simultaneous multipoint study is challenging owing to the intrinsic limitations of existing technological approaches. Here, we describe a prototype dispersive optics-based array AFM capable of simultaneously monitoring multiple probe-sample interactions. A single supercontinuum laser beam is utilized to spatially and spectrally map multiple cantilevers, to isolate and record beam deflection from individual cantilevers using distinct wavelength selection. This design provides a remarkably simplified yet effective solution to overcome the optical cross-talk while maintaining subnanometer sensitivity and compatibility with probe-based sensors. We demonstrate the versatility and robustness of our system on parallel multiparametric imaging at multiscale levels ranging from surface morphology to hydrophobicity and electric potential mapping in both air and liquid, mechanical wave propagation in polymeric films, and the dynamics of living cells. This multiparametric, multiscale approach provides opportunities for studying the emergent properties of atomic-scale mechanical and physicochemical interactions in a wide range of physical and biological networks.