RESUMO
OBJECTIVE: Immunoglobulin G (IgG) autoantibodies in systemic lupus erythematosus (SLE) are considered pathogenic, whereas immunoglobulin M (IgM) autoantibodies may have protective effects. The aim of this study was to identify whether IgG/IgM autoantibody ratios differ between patients with incomplete systemic lupus erythematosus (iSLE), patients with SLE, and healthy controls (HCs), and whether IgG/IgM autoantibody ratios relate to progression from iSLE to SLE. METHOD: This prospective cohort study included 34 iSLE patients, 41 SLE patients, and 11 HCs. IgG and IgM anti-dsDNA, anti-Ro52, and anti-Ro60 were measured by fluoro-enzyme immunoassay in serum samples obtained at baseline in all groups and in follow-up samples of up to 5 years for iSLE patients. Correlations between IgG/IgM autoantibody ratios, interferon signature, and clinical parameters were also assessed. RESULTS: At baseline, IgG anti-dsDNA, anti-Ro52, anti-Ro60, and IgM anti-dsDNA were elevated in iSLE and SLE patients. IgG/IgM anti-dsDNA and anti-Ro52 ratios were similar between groups, while IgG/IgM anti-Ro60 ratios were significantly elevated in iSLE and SLE patients compared to HCs. IgG/IgM autoantibody ratios were not correlated with interferon signature or clinical parameters. IgG/IgM ratios at baseline were similar and remained relatively stable during a median follow-up of 18 months in non-progressors and six iSLE patients who progressed to SLE. CONCLUSION: IgG anti-dsDNA, anti-Ro52, anti-Ro60, and IgM anti-dsDNA were elevated in iSLE and SLE patients, which was not apparent from the respective IgG/IgM ratios only. IgG/IgM autoantibody ratios remained relatively stable over up to 5 years in iSLE non-progressors and six patients who progressed to SLE.
Assuntos
Autoanticorpos , Lúpus Eritematoso Sistêmico , Humanos , Imunoglobulina M , Imunoglobulina G , Estudos Prospectivos , InterferonsRESUMO
The synthesis of anatase TiO2 nanoparticles with controlled morphology and increased {001} facets exposed without the presence of fluorine-derived substances is a challenge. Herein, we report a highly effective approach to fabricate anatase TiO2 nanoplates with exposed {001} facets and their exploitation as robust photocatalytic materials for dye remediation. These materials were synthesized under controlled hydrolysis and condensation reactions, using titanium (IV) n-butoxide in an ethanolic solution, with acetic and sulfuric acids, by a solvothermal method at 190 °C with or without the presence of the non-ionic surfactant Triton® X-100 and then characterized. During TiO2 crystal synthesis, the effect of a non-ionic surfactant on the TiO2 particle growth was investigated. Our results demonstrate that the proposed method can synthesize pure and crystalline anatase TiO2 square nanoplates that form nanostructured spheres with high surface area, uniformly sized mesopores, and exposed {001} facets. The presence of non-ionic surfactant increased the exposed {001} facets percentage of the formed nanoplates from 69 to 80%, decreased the crystallite thickness, but unaffected its crystalline phase and band gap energy. The kinetic constants (Ka e Kb) for the synthesized TiO2 anatase nanoplates are considerably higher than the commercial TiO2 anatase constant (Kc). The synthesized photocatalysts show higher efficiency in the photocatalytic removal of methylene blue (MB) than commercial TiO2 (for t = 120 min).
Assuntos
Azul de Metileno , Titânio , Catálise , Azul de Metileno/química , Tensoativos , Titânio/químicaRESUMO
We have previously shown that the antifungal activity of human lactoferrin (hLf) against Candida albicans relies on its ability to induce cell death associated with apoptotic markers. To gain a deeper understanding of the mechanisms underlying hLf-induced apoptosis, we characterized this cell death process in the well-established Saccharomyces cerevisiae model. Our results indicate that hLf induces cell death in S. cerevisiae in a manner that requires energy and de novo protein synthesis. Cell death is associated with nuclear chromatin condensation, preservation of plasma membrane integrity, and is Yca1p metacaspase-dependent. Lactoferrin also caused mitochondrial dysfunction associated with ROS accumulation and release of cytochrome c. Pre-incubation with oligomycin, an oxidative phosphorylation inhibitor, increased resistance to hLf and, accordingly, mutants deficient in the F1F0-ATP synthase complex were more resistant to death induced by hLf. This indicates that mitochondrial energetic metabolism plays a key role in the killing effect of hLf, though a direct role of F1F0-ATP synthase cannot be precluded. Overexpression of the anti-apoptotic protein Bcl-xL or pre-incubation with N-acetyl cysteine reduced the intracellular level of ROS and increased resistance to hLf, confirming a ROS-mediated mitochondrial cell death process. Mitochondrial involvement was further reinforced by the higher resistance of cells lacking mitochondrial DNA, or other known yeast mitochondrial apoptosis regulators, such as, Aif1p, Cyc3p and Aac1/2/3p. This study provides new insights into a detailed understanding at the molecular level of hLf-induced apoptosis, which may allow the design of new strategies to overcome the emergence of resistance of clinically relevant fungi to conventional antifungals.
Assuntos
Antifúngicos/farmacologia , Apoptose , Lactoferrina/farmacologia , Saccharomyces cerevisiae/citologia , Humanos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacosRESUMO
The prospective project MOSAR was conducted in five rehabilitation units: the Berck Maritime Hôpital (Berck, France), Fondazione Santa Lucia (Rome, Italy), Guttmann Institute (GI; Barcelona, Spain), and Loewenstein Hospital and Tel-Aviv Souraski Medical Center (TA) (Tel-Aviv, Israel). Patients were screened for carriage of Enterobacteriaceae resistant to expanded-spectrum cephalosporins (ESCs) from admission until discharge. The aim of this study was to characterize the clonal structure, extended-spectrum ß-lactamases (ESBLs), and acquired AmpC-like cephalosporinases in the Escherichia coli populations collected. A total of 376 isolates were randomly selected. The overall number of sequence types (STs) was 76, including 7 STs that grouped at least 10 isolates from at least three centers each, namely, STs 10, 38, 69, 131, 405, 410, and 648. These clones comprised 65.2% of all isolates, and ST131 alone comprised 41.2%. Of 54 STs observed only in one center, some STs played a locally significant role, like ST156 and ST393 in GI or ST372 and ST398 in TA. Among 16 new STs, five arose from evolution within the ST10 and ST131 clonal complexes. ESBLs and AmpCs accounted for 94.7% and 5.6% of the ESC-hydrolyzing ß-lactamases, respectively, being dominated by the CTX-M-like enzymes (79.9%), followed by the SHV (13.5%) and CMY-2 (5.3%) types. CTX-M-15 was the most prevalent ß-lactamase overall (40.6%); other ubiquitous enzymes were CTX-M-14 and CMY-2. Almost none of the common clones correlated strictly with one ß-lactamase; although 58.7% of ST131 isolates produced CTX-M-15, the clone also expressed nine other enzymes. A number of clone variants with specific pulsed-field gel electrophoresis and ESBL types were spread in some locales, potentially representing newly emerging E. coli epidemic strains.
Assuntos
Proteínas de Bactérias/genética , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Escherichia coli/genética , beta-Lactamases/genética , Técnicas de Tipagem Bacteriana , Células Clonais , Eletroforese em Gel de Campo Pulsado , Escherichia coli/classificação , Escherichia coli/enzimologia , Infecções por Escherichia coli/epidemiologia , Europa (Continente)/epidemiologia , Humanos , Israel/epidemiologia , Filogenia , Filogeografia , beta-Lactamases/classificaçãoRESUMO
The international project MOSAR was conducted in five rehabilitation centers; patients were screened for rectal carriage of extended-spectrum ß-lactamase (ESBL)-producing members of the Enterobacteriaceae. Among 229 Klebsiella pneumoniae isolates, four clonal groups (CG) or complexes (CC) prevailed: CG17 in France, CG101 in Italy, CG15 in Spain, and CC147 in Israel. ESBLs, mainly CTX-Ms, were produced by 226 isolates; three isolates expressed AmpC-like cephalosporinases. High genetic diversity of K. pneumoniae populations was observed, with specific characteristics at each center.
Assuntos
Klebsiella pneumoniae/enzimologia , Centros de Reabilitação , beta-Lactamases/metabolismo , França , Genética Populacional , Israel , Itália , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , Espanha , beta-Lactamases/genéticaRESUMO
OBJECTIVE: To measure by consensus the level of innovation and its potential within the physical medicine and rehabilitation (PM&R) medical specialists. METHOD: Three consecutive techniques are applied using digital tools for consensus among professionals, first synchronously to a group of 17 professionals; posteriorly extended to a group of 169 professionals who participate asynchronously and the third technique is done synchronously with 25 physiatrists. RESULTS: The analysis of the consensus done by the PM&R physicians on the innovation potential of the group during October and November 2020 shows: starting situation, strengths and weaknesses, as well as their innovation priorities. CONCLUSIONS: PM&R physicians believe that innovation could improve the cost-effectiveness of their departments, and could increase their clinical efficiency, also that to innovate they need a close relationship with the industry.
Assuntos
Fisiatras , Medicina Física e Reabilitação , Humanos , ConsensoRESUMO
Tourism sustainability is a long-term exploration process of human beings seeking to coexist harmoniously with the ecological environment. The core of sustainable tourism development is to achieve the harmonious development of the economy, society, and environment. Aragon's rich tourism resources attract many tourists, and the local government has formulated a sustainable development strategy to develop tourism vigorously. This paper constructs a tool to assess the sustainable development of tourism in Aragon based on the theory of sustainable tourism development and related methods. It proposes the construction of synthetic indicators based on the environmental-social-economic triad model, identifies individual indicators suitable for the study of the region based on indicators that appear more frequently in related studies, and defines and evaluates these indicators. We construct the matrices by questionnaire and expert consultation method and find that environmental and social factors significantly impact sustainable development. The indicators are then standardized and weighted using hierarchical analysis to determine the level of sustainable development of the local tourism industry based on the standard for assessing sustainable tourism development. The steps and methods of constructing synthetic indicators proposed in this paper can guide future analysis of the strengths and weaknesses of tourism development in Aragon and similar areas under different conditions, as well as for the study of factors affecting tourism development, and provide targeted suggestions for improving the competitiveness of local tourism, taking into account regional tourism characteristics and actual conditions.
RESUMO
This work analyzes the influence of cerium content (6-15 wt%) on a TiO(2) support over the structure and water gas shift (WGS) activity of Pt catalysts. The structural properties of these Pt/Ce-TiO(2) catalysts were characterized by XRD, TEM and XANES. Physicochemical characterization of the catalysts showed differences in the structure and dispersion of Ce entities on the support with Ce loading. For the samples with low ceria content (6 wt%), cerium is deposited on the support in the form of CeO(x) clusters in a highly dispersed state in close interaction with the Ti atoms. The formation of CeO(x) clusters at low Ce-loading on the support facilitates the dispersion of small particles of Pt and improves the reducibility of ceria component at low temperatures. The changes in platinum dispersion and support reducibility with Ce-loading on the TiO(2) support lead to significant differences in the WGS activity. Pt supported on the sample with lower Ce content (6 wt%) shows better activity than those corresponding to catalysts with higher Ce content (15 wt%). Activity measurements coupled with catalysts characterization suggest that the improvement in the reducibility of the support with lower Ce content was associated with the presence of CeO(x) clusters of high reducibility that improve the chemical activity of the oxide-metal interfaces at which the WGS reaction takes place.
RESUMO
The combustion of coal can result in trace elements, such as mercury, being released from power stations with potentially harmful effects for both human health and the environment. Research is ongoing to develop cost-effective and efficient control technologies for mercury removal from coal-fired power plants, the largest source of anthropogenic mercury emissions. A number of activated carbon sorbents have been demonstrated to be effective for mercury retention in coal combustion power plants. However, more economic alternatives need to be developed. Raw biomass gasification chars could serve as low-cost sorbents for capturing mercury since they are sub-products generated during a thermal conversion process. The aim of this study was to evaluate different biomass gasification chars as mercury sorbents in a simulated coal combustion flue gas. The results were compared with those obtained using a commercial activated carbon. Chars from a mixture of paper and plastic waste showed the highest retention capacity. It was found that not only a high carbon content and a well developed microporosity but also a high chlorine content and a high aluminium content improved the mercury retention capacity of biomass gasification chars. No relationship could be inferred between the surface oxygen functional groups and mercury retention in the char samples evaluated.
Assuntos
Poluentes Atmosféricos/isolamento & purificação , Poluição do Ar/prevenção & controle , Carvão Vegetal/química , Mercúrio/isolamento & purificação , Biomassa , Centrais ElétricasRESUMO
A series of bulk and Al(2)O(3)-supported perovskite oxides of the type LaMn(1-x-y)Fe(x)Mo(y)O(3) (x = 0.00-0.90 and y = 0.00-0.09) were synthesized by the citric acid complexation-gelation method followed by annealing in air at 800 degrees C. For all samples, the local environment and the chemical state and concentration of surface species were determined. Mössbauer spectra revealed the only presence of octahedral Fe(3+) ions dispersed in the perovskite structure, however well-crystallized together with a poorly crystalline LaFeO(3) phases were detected for larger substitutions (x = 0.90). A similar picture was obtained for Mo-loaded (y = 0.02 and 0.05) samples but a new phase most likely related to Fe(3+) ions dispersed aside from the perovskite structure was found for larger substitutions (y = 0.09). Together with these structures, supported samples showed the presence of LaFeO(3) nanoparticles. Finally, photoelectron spectroscopy indicated that the chemical state and composition of the samples in the surface region (2-3 nm) approaches that of the bulk. For the unsupported substituted samples, iron (and molybdenum) enters into the perovskite structure while manganese tends to be slightly segregated. Moreover, in supported perovskites, a fraction of Mo and La atoms interact with the alumina surface. All these oxides were active in methane combustion and best performance was recorded for the Fe-rich composition (x = 0.9) in which both Mn(3+) and Mo(3+) ions were in the same proportion (y = 0.05).
RESUMO
The modification of Cu-Zn catalysts with low amount of Al and Ga (Al+Ga = 3%) was investigated and data corresponding to its influence on the decomposition of the calcined precursors and on the nanomorphology and surface concentration of reduced catalysts were presented in this contribution. The data presented here are supplementary material of the catalysts presented in the research article "Structure and activity of Cu/ZnO catalysts co-modified with aluminium and gallium for methanol synthesis" published in Catalysis Today [1].
RESUMO
Technological approaches which enable the effective utilization of CO2 for manufacturing value-added chemicals and fuels can help to solve environmental problems derived from large CO2 emissions associated with the use of fossil fuels. One of the most interesting products that can be synthesized from CO2 is methanol, since it is an industrial commodity used in several chemical products and also an efficient transportation fuel. In this review, we highlight the recent advances in the development of heterogeneous catalysts and processes for the direct hydrogenation of CO2 to methanol. The main efforts focused on the improvement of conventional Cu/ZnO based catalysts and the development of new catalytic systems targeting the specific needs for CO2 to methanol reactions (unfavourable thermodynamics, production of high amount of water and high methanol selectivity under high or full CO2 conversion). Major studies on the development of active and selective catalysts based on thermodynamics, mechanisms, nano-synthesis and catalyst design (active phase, promoters, supports, etc.) are highlighted in this review. Finally, a summary concerning future perspectives on the research and development of efficient heterogeneous catalysts for methanol synthesis from CO2 will be presented.
RESUMO
The influence of aging of precipitates on the physical and catalytic properties of a copper/zinc oxide-aluminium (Cu/ZnO-Al) catalyst with an optimized composition (low Al concentration, Cu/Zn/Al = 68/29/3) prepared using co-precipitation has been investigated in detail. The change in the structure of precipitates with aging (from amorphous zincian georgeite to crystalline zincian malachite) strongly influences the micro- and nano-structure (Cu and ZnO crystallite size, exposed copper surface area, Cu-ZnO interactions and stability of ZnO) of the final Cu/ZnO-Al catalysts obtained after calcination and reduction of the precipitates. The results of catalytic activity in methanol synthesis from syngas show the higher intrinsic activity of the catalysts derived from aged zincian malachite precipitates as consequence of the increase in the exposed copper surface area and the Cu-ZnO contacts. The stability of catalysts under the reaction conditions was also improved in the catalysts derived from precipitates aged after crystallization of malachite. The catalyst derived from the precipitate removed close to the point of crystallization of malachite shows very poor activity in the methanol synthesis as consequence of its segregated large Cu crystallites in low contact with ZnO derived from the absence of carbonate retention after calcination of the precipitate and the presence of sodium species after conventional washing which favour the strong sintering and crystallization of Cu during reduction.
RESUMO
OBJECTIVE: To describe the clinical-epidemiological characteristics of a case series of fungal keratitis associated with Fusarium spp.., in Spain during the years 2012 to 2014. METHODS: A retrospective study of a case series was conducted on a systematic random sample of 10% of patients identified in Health Centres of provincial capitals (n=250). The centres were asked whether they had been presented with cases of Fusarium spp. keratitis characterised by microbiological methods. Of the 23 centres that responded, 14 had detected cases, with 13 of them accepting to participate, and 11 of them completing the study. The latter being sent a previously validated questionnaire. The variables analysed were: age, gender, habitual residence, profession, disease and medical history (previous systemic and ocular diseases, previous eye surgeries), and their outcomes. RESULTS: The response rate was 92%, identifying 23 cases of Fusarium spp.. of which 21 (91.3%) of them lived in urban areas. The professions most affected by the disease included chefs, administrative, and technical, with 13 cases (56.5%). The treatment guidelines established to confirm the infection showed the combined use of topical antibiotics associated with antiviral and/or antifungal agents. The use of contact lenses (86.9%) was the main risk factor. DISCUSSION: This study showed that this is a rare disease in Spain, but that a large percentage of people who present with the disease are resident in urban areas, and they work in closed environments, focusing attention on microtraumas caused by use of contact lenses.
Assuntos
Infecções Oculares Fúngicas/microbiologia , Fusariose/epidemiologia , Ceratite/microbiologia , Adulto , Idoso , Anti-Infecciosos/uso terapêutico , Lentes de Contato/microbiologia , Quimioterapia Combinada , Contaminação de Equipamentos , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/epidemiologia , Feminino , Fusariose/tratamento farmacológico , Fusariose/microbiologia , Fusarium/isolamento & purificação , Humanos , Ceratite/tratamento farmacológico , Ceratite/epidemiologia , Masculino , Pessoa de Meia-Idade , Ocupações , Infecções Oportunistas/tratamento farmacológico , Infecções Oportunistas/epidemiologia , Infecções Oportunistas/microbiologia , Estudos Retrospectivos , Fatores de Risco , Estudos de Amostragem , Fatores Socioeconômicos , Espanha/epidemiologia , Adulto JovemRESUMO
INTRODUCTION: The objective of this study was to evaluate the awareness and training needs on biosimilar drugs in Primary Care (PC) physicians. MATERIAL AND METHODS: Descriptive cross-sectional study based on an on-line questionnaire with a total of 34 multiple choice questions, published on the SEMERGEN website. The main Knowledge areas were: biosimilar definition; regulatory and legal framework; prescription, traceability, interchangeability and pharmacovigilance; availability of biosimilars in the PC setting, and the biosimilars contribution to sustainability. The software used for the analysis and data processing was the Barbwin 7.5. RESULTS: An analysis was performed on the responses from 701 questionnaires completed. There was a slight majority (57%) of women participants. The majority of participant worked in urban centres (60.91%). The definition of biosimilar was not known by 58% of those that responded, and 73% were unaware that the management of biosimilars and generics was not comparable. Most (84%) of those that responded were not aware that the studies required for the approval of biosimilars is different from reference biological medicines. Around two-thirds (66%) those that responded did not know of any biosimilars available in PC setting, and the 94% were also unaware of the Spanish legal framework for the management of biosimilar medicines. CONCLUSIONS: The current knowledge about biosimilars among PC physicians is low. The critical areas in need of further training include specific information on biosimilars currently available in PC setting, as well as key aspects regarding prescription, interchangeability and pharmacovigilance requirements. Six out of ten doctors do not know of any biosimilar used in PC in Spain.
Assuntos
Produtos Biológicos/administração & dosagem , Medicamentos Biossimilares/administração & dosagem , Conhecimentos, Atitudes e Prática em Saúde , Médicos de Atenção Primária/normas , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Farmacovigilância , Atenção Primária à Saúde/normas , Espanha , Inquéritos e QuestionáriosRESUMO
Dendritic cells (DCs) are professional antigen presenting cells with the ability to induce and regulate an immune response. DCs that capture and present antigen under noninflammatory conditions maintain an immature phenotype and acquire tolerogenic properties. These DCs generate regulatory T lymphocytes that potentiate tolerogenic responses. Here we developed a method for the generation of immature murine DCs able to process and present a specific antigen in a tolerogenic context. Immature DCs were prepared from bone marrow precursors after differentiation with granulocyte-macrophage colony-stimulating factor (GM-CSF) in the presence of vitamin D(3) and characterized by their low expression of major histocompatibility complex class (MHC) II and CD86 molecules. Purified phagosomes containing either MHC II molecules or ovalbumin were used to deliver antigens to immature DCs. More than 80% of the DCs captured the phagosomes, while maintaining a low expression of maturation markers and showing basal levels of secretion of activating cytokines such as interleukin (IL)-2 and IL-12. Treatment of the immature DCs with lipopolysaccharides (LPS) increased IL-10 secretion, in agreement with their anti-inflammatory and immune regulatory properties. Cocultures of transgenic OT-II T lymphocytes with the immature DCs carrying OVA-phagosomes succeeded in generating a subpopulation of regulatory T lymphocytes characterized by the expression of CD4, CD25, CD62L, and Foxp3. Taken together, our results suggest that vitamin D(3) generates immune tolerance through the modulation of DC phenotype and could be useful to induce tolerance to allotransplants.
Assuntos
Células Dendríticas/imunologia , Linfócitos T Reguladores/imunologia , Animais , Antígeno B7-2/efeitos dos fármacos , Células da Medula Óssea/imunologia , Calcitriol/farmacologia , Diferenciação Celular , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Antígenos de Histocompatibilidade Classe II/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Ovalbumina/genética , Fagocitose/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T Reguladores/efeitos dos fármacosRESUMO
A series of Fe-Ce mixed oxides (95 atom % Fe-5 atom % Ce) has been prepared by different methods: coprecipitation, impregnation, and physical mixture of Ce and Fe oxides. These solids have been tested in the Fischer-Tropsch synthesis. The characterization of the catalytic precursors was carried out by X-ray diffraction (XRD), Raman, Mössbauer, and X-ray photoelectron (XPS) spectroscopic techniques. When the preparation method ensures a microscopic contact between Fe and Ce cations in the solid, several types of Fe-Ce interactions are present in the calcined solids. The interactions take the shape of Fe-O-Ce bridges that can exist either in the hematite-like solid solution or in the interphase between the Fe oxide covered by microcrystals of Ce oxide. In the case of the hematite-like solid solution, Ce(IV) cations are dissolved in the alpha-Fe2O3 network. The promotion by Ce of the catalytic properties observed in the final catalysts can be directly related with the detection of these Fe-O-Ce bridges in the calcined solids. The Ce promotion results in a larger yield to hydrocarbons, a higher production of olefins, and a higher selectivity to medium and large chain hydrocarbons (larger than six carbon atoms). It is proposed that the Ce promotion is due to the presence of Fe0-Ce(III) ensembles in the final catalysts arising from the initial Fe-O-Ce bridges developed in the parent calcined samples.
Assuntos
Injúria Renal Aguda/complicações , Injúria Renal Aguda/diagnóstico , Imunoglobulina A/análise , Túbulos Renais/patologia , Síndrome Nefrótica/complicações , Síndrome Nefrótica/diagnóstico , Anti-Inflamatórios/uso terapêutico , Anticoagulantes/uso terapêutico , Biópsia , Ciclofosfamida/uso terapêutico , Diagnóstico Diferencial , Feminino , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Imunossupressores/uso terapêutico , Metilprednisolona/uso terapêutico , Pessoa de Meia-Idade , Necrose , Síndrome Nefrótica/tratamento farmacológico , Síndrome Nefrótica/imunologia , Prednisona/uso terapêutico , Radiografia , Veias Renais/diagnóstico por imagem , Trombose Venosa/complicações , Trombose Venosa/diagnóstico por imagem , Trombose Venosa/tratamento farmacológico , Varfarina/uso terapêuticoRESUMO
The preparation of graphene suspensions in water, without detergents or any other additives is achieved using freeze-dried graphene powders, produced by mechanochemical exfoliation of graphite. These powders of graphene can be safely stored or shipped, and promptly dissolved in aqueous media. The suspensions are relatively stable in terms of time, with a maximum loss of â¼25% of the initial concentration at 2 h. This work provides an easy and general access to aqueous graphene suspensions of chemically non-modified graphene samples, an otherwise (almost) impossible task to achieve by other means. A detailed study of the stability of the relative dispersions is also reported.