Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 349
Filtrar
1.
Phys Chem Chem Phys ; 26(26): 18173-18181, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38899760

RESUMO

The present work deals with a comprehensive computational theoretical study of the molecular CO and O2 adsorption on 3d single atoms (M/MgO(100)). The study is based on the chemical elements of the 3d row, as they represent an economic advantage compared with the so-called noble metals. The present study has been performed employing density functional theory calculations. Through the representation of the metastable states, we perform a synergetic analysis of the CO oxidation reaction to find trends that suggest the possible use of new candidates such as Ni/MgO(100) or Cu/MgO(100) single-atom catalysts, for this type of redox reaction. We found that Ni and Cu produce energetically viable CO to CO2 reactions. Ni and Cu atoms show the greatest diffusion barrier and are the best candidates due to their low sintering capability. The energetic and electronic properties of the single Cu and Ni atoms on MgO (100) give them the best characteristics to help in the CO oxidation process.

2.
Sci Rep ; 14(1): 9359, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654068

RESUMO

The present work aimed to study different parts of colored cotton waste through energetic characterization and analytical flash pyrolysis. Stalks and bolls of BRS cotton cultivars from Sementes do Brasil (Green, Ruby, Topaz and Jade) were studied, using white cotton (BRS 286) as a comparison. The energetic potential of biomass was evaluated by bulk density, High Heating Value (HHV), proximate and ultimate analysis, compositional and thermogravimetric analysis (TGA). Pyrolysis was performed in a micro-pyrolyzer and the products were identified by gas chromatography and mass spectroscopy (Py-GC/MS). The results indicated a significant energetic potential, suggesting that can be used as an alternative energy source for thermochemical processes. The results of conventional pyrolysis indicated the presence of oxygenated compounds of different organic groups: aldehydes, ketones, phenols, furans and ethers, characteristic of the decomposition of lignocellulosic materials. Light organic acids in the C1-C4 range stood out the most, followed by phenols that appeared in a considerable proportion. Finally, it is concluded that the energy potential and pyrolysis products of the different parts (stalks and bolls) of colored cotton waste can be used to generate bioenergy and various chemical compounds of plant origin from green chemistry.

3.
BMC Health Serv Res ; 22(1): 680, 2022 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-35597936

RESUMO

BACKGROUND: The existing digital healthcare solutions demand a service development approach that assesses needs, experience, and outcomes, to develop high-value digital healthcare services. The objective of this study was to develop a digital transformation of the patients' follow-up service after cardiac surgery, based on a remote patient monitoring service that would respond to the real context challenges. METHODS: The study followed the Design Science Research methodology framework and incorporated concepts from the Lean startup method to start designing a minimal viable product (MVP) from the available resources. The service was implemented in a pilot study with 29 patients in 4 iterative develop-test-learn cycles, with the engagement of developers, researchers, clinical teams, and patients. RESULTS: Patients reported outcomes daily for 30 days after surgery through Internet-of-Things (IoT) devices and a mobile app. The service's evaluation considered experience, feasibility, and effectiveness. It generated high satisfaction and high adherence among users, fewer readmissions, with an average of 7 ± 4.5 clinical actions per patient, primarily due to abnormal systolic blood pressure or wound-related issues. CONCLUSIONS: We propose a 6-step methodology to design and validate a high-value digital health care service based on collaborative learning, real-time development, iterative testing, and value assessment.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Atenção à Saúde , Seguimentos , Humanos , Aprendizagem , Projetos Piloto
4.
Theriogenology ; 125: 224-235, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30472502

RESUMO

There is a complex cascade involving proteins during early embryo development and maternal recognition, which is very important for maintenance of a conceptus. The aim of this study was to compare proteomic profile of uterine fluid after ovulation in pregnant and cyclic mares. In the first cycle, samples of uterine fluid of 30 cyclic mares were collected on days 7 (n = 10), 10 (n = 10) and 13 (n = 10) post ovulation and constituted the Cyclic group. In the second cycle, the same mares were bred to a fertile stallion. At days 7, 10 and 13 uterine fluid samples were collected. Immediately after sample collection, the mare's uteri were flushed, and those with an embryo recovered were assigned to the Pregnant group. Of the 30 mares flushed embryos were recovered from 6 mares on day 7, 6 on day 10 and 6 on day 13. Samples from the mares without embryo recovery were excluded from both groups. The uterine fluid samples were processed by two-dimensional electrophoresis technique followed by matrix assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry for the identification of relevant protein spots. From a total of 677 detected spots 19 were identified, 13 more abundant in Pregnant group and 6 in Cyclic group. In summary, pregnant and cyclic mares showed proteins with different abundance. Identified proteins were related to the transport of lipids through the embryo capsule, uterine motility, ATP generation, maternal immunological tolerance, cell proliferation, differentiation, metabolism and angiogenesis. Changes in the proteomic profile of uterine fluid during early embryo development in mares were related with the conceptus presence, suggesting that these alterations may be important for conceptus development and maternal recognition of pregnancy.


Assuntos
Embrião de Mamíferos/fisiologia , Desenvolvimento Embrionário/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Cavalos/embriologia , Proteômica/métodos , Animais , Líquidos Corporais/química , Feminino , Gravidez , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
8.
Eur J Neurol ; 18(3): 436-41, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20880070

RESUMO

BACKGROUND: Multiple mitochondrial DNA (mtDNA) deletions usually have a mendelian inheritance secondary to mutation in nuclear genes. One of these is the Twinkle gene whose mutation is responsible for autosomal dominant progressive external ophthalmoplegia (PEO). The number of reported cases with mainly myopathic symptoms and possible nervous system involvement related to Twinkle gene mutation is limited. We present a new French family of whom two members displayed myopathy and neuropathy associated with PEO, and we perform a clinical review in light of other observations reported in the literature. METHODS: The proband, one son and the daughter have been investigated. Southern blot analysis and long-range PCR assay have been performed from muscle biopsy specimens. Coding exons and flanking intron regions of polymerase gamma (POLG) and DNA helicase (Twinkle) genes were sequenced. RESULTS: Multiple mitochondrial DNA deletions have been found and sequencing of the Twinkle gene showed the change p.R374Q. CONCLUSION: Two other families from the literature also had the R374Q mutation. Symptoms reported in association with this mutation were myopathy, peripheral neuropathy, dysarthria and/or dysphagia, respiratory insufficiency and parkinsonism. Respiratory insufficiency caused by chest wall weakness was reported in other families with different Twinkle gene mutations, and one might provide exercise intolerance, dysarthria and/or dysphagia as symptoms in favor of the diagnosis. Occurrence of impressive emaciation was a peculiarity in our family.


Assuntos
DNA Helicases/genética , Mutação , Oftalmoplegia Externa Progressiva Crônica/genética , Biópsia , Southern Blotting , DNA Mitocondrial/genética , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Mitocondriais , Músculo Esquelético/patologia , Oftalmoplegia Externa Progressiva Crônica/patologia , Oftalmoplegia Externa Progressiva Crônica/fisiopatologia , Linhagem , Reação em Cadeia da Polimerase , Adulto Jovem
9.
Clin Neuropathol ; 29(2): 59-64, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20175953

RESUMO

OBJECTIVE: Most cases of familial amyloid polyneuropathy are identified by molecular genetic analysis of the transthyretin (TTR) gene. However, it is not uncommon to find unexpected amyloid deposits marked by the anti-TTR serum in the endoneurium of aged patients. Light chain amyloid deposits may also be found in the endoneurium. During these past 5 years, we studied the muscle and nerve biopsies from 6 patients which revealed amyloid deposits. There were 2 patients with an idiopathic polyneuropathy and 4 with monoclonal gammopathy (MG). METHODS: In each case, specimens from the superficial peroneal nerve and peroneus brevis muscle were taken by the same cutaneous incision. RESULTS: Amyloid deposits were visible in the endoneurium of 2 cases and only on muscle specimens in 3 other cases, 1 with a MG and 2 with an idiopathic polyneuropathy. Amyloid deposits were strongly stained with the anti-TTR serum in the muscle specimens of the 2 idiopathic cases, mainly located in vessel walls. In one patient with polyneuropathy and MG, a small endoneurial amyloid deposit surprisingly revealed to be immunostained by the anti-TTR serum. In another case, a small amyloid deposit in close relationship with a macrophage was only visible in the endoneurium by electron microscopy. COMMENTS: Amyloid deposits were only visible on muscle fragments in 3 cases and were strongly marked by the anti-TTR serum in 2 of them, indicating their familial origin. Combining muscle and nerve biopsy raises the number of cases with visible amyloid deposits.


Assuntos
Neuropatias Amiloides/diagnóstico , Músculo Esquelético/patologia , Nervo Fibular/patologia , Idoso , Neuropatias Amiloides/genética , Neuropatias Amiloides/cirurgia , Biópsia , Feminino , Imunofluorescência , Humanos , Imuno-Histoquímica , Masculino , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , Músculo Esquelético/cirurgia , Nervo Fibular/cirurgia , Pré-Albumina/genética , Pré-Albumina/metabolismo
12.
Clin Neuropathol ; 27(2): 96-105, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18402389

RESUMO

There are several reviews devoted to neurosarcoidosis and a few reports restricted to sarcoid neuropathy. Since 1989, we have investigated 4 new cases of sarcoid neuropathy, 1 with chronic sensory motor neuropathy (CSMN), another with painful neuropathy and 2 with atypical chronic inflammatory demyelinating polyneuropathy (CIDP). In each case, biopsy specimens from the superficial peroneal nerve and peroneus brevis muscle were taken by the same cutaneous incision and studied on paraffin sections, semi-thin sections and under electron microscope. We compared neuropathological findings from our 4 cases with those from 34 well-studied nerve biopsies previously reported in the literature, and which concerned 16 cases of CSMN, 13 cases ofmononeuropathy multiplex, 2 cases of painful neuropathy and three cases of CIDP. In all of these 38 cases of sarcoid neuropathy, the characteristic noncaseiting granulomas (NCG) were observed on the nerve in 11 cases, on the muscle alone in 5, on both muscle and nerve in 10, and in the nerve and another parenchyma in 4. In the 8 remaining cases, NCG were observed in another parenchyma, mainly lung or lymph nodes. Moreover, necrotizing vasculitis was present in nerve biopsies from 8 cases and microvasculitis without obvious necrosis in 2 others. Nerve fiber lesions, which are mainly axonal, are probably related to mechanical compression by NCG and/or to an ischemic process due to vasculitis. Cytokines and immune factors may also play a role, especially in certain cases with a clinical presentation of CIDP.


Assuntos
Doenças do Sistema Nervoso Periférico/patologia , Doenças do Sistema Nervoso Periférico/fisiopatologia , Sarcoidose/patologia , Sarcoidose/fisiopatologia , Idoso , Feminino , Granuloma/patologia , Humanos , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Doenças do Sistema Nervoso Periférico/etiologia , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/etiologia , Sarcoidose/complicações
13.
Clin Neuropathol ; 26(1): 28-31, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17290934

RESUMO

OBJECTIVE: To elucidate the cause and mechanisms of nerve fiber lesions in a case of mononeuropathy multiplex (MNM). MATERIAL AND METHODS: A 65-year-old man had a MNM for 6 months and no previous history of peripheral nerve impairment was known. He underwent a muscle and nerve biopsy by the same skin incision on the right leg. RESULTS: Paraffin-embedded fragments from the superficial peroneal nerve and peroneous brevis muscle disclosed characteristic lesions of necrotizing vasculitis. Complement had low levels, but a search for cryoglobulinemia was negative. Two months later a purpura appeared in the lower limbs and a mixed Type II cryoglobulinemia was disclosed, whereas a search for hepatitis C virus (HCV) remained negative. Five months later the blood contained 8,600 lymphocytes/mm3 and a low grade B cell lymphoma was disclosed in the bone marrow. CONCLUSIONS: Although not having HCV infection, our patient had mixed Type II cryoglobulinemia, necrotizing vasculitis and B cell lymphoma. Each of these three abnormalities might be in part responsible for nerve fibers impairment, with acute axonal degeneration. Mixed cryoglobulinemia must be searched carefully in patients with vasculitic neuropathy.


Assuntos
Crioglobulinemia/complicações , Linfoma de Células B/complicações , Mononeuropatias/etiologia , Vasculite/complicações , Idoso , Crioglobulinemia/diagnóstico , Humanos , Linfoma de Células B/diagnóstico , Masculino , Vasculite/diagnóstico
14.
Arq. bras. med. vet. zootec ; 58(2): 175-183, abr. 2006. ilus
Artigo em Português | LILACS | ID: lil-432668

RESUMO

Avaliaram-se os compósitos de hidroxiapatita sintética e carbono (HAC) e hidroxiapatita sintética, carbono e fosfato biácido de sódio (HACF), ambos na forma sólida, como substituto ósseo em 36 coelhos adultos. Após protocolos anestésico e cirúrgico habituais, retirou-se um fragmento de aproximadamente 2cm de comprimento no terço médio da ulna esquerda. Os animais do grupo 1 receberam, em cada falha provocada, blocos de HAC e HACF, e os do grupo 2 somente HAC. Os do grupo 3 não receberam tratamento. Os animais foram submetidos a avaliações clínicas e radiológicas nos dias 8, 15, 30, 60, 120 e 180 de pós-operatório. Nas mesmas datas, dois animais de cada grupo foram sacrificados e deles colheu-se material para histologia. Observou-se evolução normal da regeneração óssea em todos os animais, sendo mais precoce nos dos grupos que receberam os compósitos. O uso de HAC e HACF na ulna de coelho mostrou-se um método eficiente, não apresentando sinais de infecção e nem evidência de rejeição.


Assuntos
Animais , Regeneração Óssea , Coelhos/anatomia & histologia , Durapatita/administração & dosagem , Durapatita/uso terapêutico , Ulna/anormalidades , Ulna/cirurgia
15.
Rev Neurol (Paris) ; 160(3): 285-95, 2004 Mar.
Artigo em Francês | MEDLINE | ID: mdl-15037841

RESUMO

POEMS is an acronym for polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes. POEMS syndrome is also called Crow-Fukase syndrome, chiefly in Japan. The 5 above mentioned features are not always present at the first examination. The minimal criteria to establish the diagnosis are the presence of a demyelinating and axonal polyneuropathy associated with an IgA or IgG monoclonal gammopathy, the light chain being almost always lambda, and at least 2 of the 8 other features: sclerosing plasmocytoma, endocrinopathy, skin changes, organomegaly, Castleman's disease, anasarca, papillary edema or thrombocytosis. Among these features, only cutaneous glomeruloid angioma are specific. Ultrastructural identification of uncompacted myelin lamellae on the peripheral nerve biopsy is also a strong argument in favor of the diagnosis. An associated "osteosclerotic" bone lesion must be carefully searched, because its treatment may improve the other features of the syndrome, especially the neuropathy. Cytokines and the vascular growth endothelial factor might play a role in the pathogenesis of this rare multisystemic disorder.


Assuntos
Síndrome POEMS , Humanos , Síndrome POEMS/complicações , Síndrome POEMS/diagnóstico , Síndrome POEMS/etiologia , Síndrome POEMS/terapia
17.
J Neurol Neurosurg Psychiatry ; 74(9): 1262-6, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12933931

RESUMO

BACKGROUND: Peripheral neuropathies (PN) associated with monoclonal gammopathy (MG) are widely considered as autoimmune disorders, but the putative role of incriminated antigens is still not understood. OBJECTIVE: Fifty five patients with PN associated with MG were studied to investigate whether new antigens could be found, and to evaluate their relation to clinical manifestations. METHODS: An immunological study was conducted on patient sera to identify autoreactivities against nerve proteins by western blotting. Antigen proteins were purified and analysed by proteomic tools. Correlation with ultrastrucural and clinical features was then studied. RESULTS: Of the 55 patients suffering from PN associated with MG, 17 exhibited IgG autoantibodies directed against peripheral nerve proteins of 35, 58, and 60 kDa. N-terminal microsequencing and mass spectrometry analyses of the 35 kDa protein revealed perfect peptidic matching with 47% of the amino acid sequence of P0, whereas the 58 and 60 kDa proteins were identified as the reduced and non-reduced forms of a P0 dimer. Deglycosylation did not affect IgG binding to the 35 kDa P0 related protein, suggesting a peptidic epitope. In contrast, deglycosylation abolished IgG recognition of the P0 dimer protein, so that a carbohydrate moiety may be implicated in the epitope formation. This confirmed the existence of two different types of IgG, one recognising the 58 and 60 kDa proteins and one directed against the 35 kDa protein. CONCLUSIONS: This is the first report of antibody activity directed against the dimeric association of P0. Although P0 oligomerisation and adhesion properties play a crucial part in the myelin sheath compaction, the pathogenic significance of these autoantibodies needs further investigations to be elucidated.


Assuntos
Antígenos/análise , Imunoglobulina G/análise , Proteína P0 da Mielina/imunologia , Paraproteinemias/imunologia , Animais , Autoanticorpos/análise , Western Blotting , Ensaio de Imunoadsorção Enzimática , Humanos , Proteína P0 da Mielina/análogos & derivados , Paraproteinemias/patologia , Ratos , Ratos Sprague-Dawley
18.
Arch Mal Coeur Vaiss ; 96(6): 631-5, 2003 Jun.
Artigo em Francês | MEDLINE | ID: mdl-12868344

RESUMO

Amyloidosis is characterised by extracellular deposits of a heterogenous protein. Compared with secondary forms, hereditary amyloidosis due to genetic mutations is rare. The authors report the cardiac manifestations in a French family of 5 sisters and 1 brother, three of whom presented with amyloidosis with deposits of transthyretin and apolipoprotein A1 due to a new genetic mutation.


Assuntos
Amiloidose/genética , Apolipoproteína A-I/genética , Cardiopatias/etiologia , Mutação , Pré-Albumina/genética , Adulto , Amiloidose/diagnóstico , Amiloidose/fisiopatologia , Ecocardiografia , Eletrocardiografia , Feminino , França , Cardiopatias/diagnóstico por imagem , Cardiopatias/fisiopatologia , Humanos , Masculino
19.
Rev Neurol (Paris) ; 159(1): 31-42, 2003 Jan.
Artigo em Francês | MEDLINE | ID: mdl-12618651

RESUMO

We studied the clinical features, the natural history and disability in 47 progressive supranuclear palsy patients and brain imaging aspects by routinely performed MRI in a subgroup of 25. Unexplained falls together with atypical parkinsonism (symmetric, levodopa unresponsive without resting tremor) are good clinical pointers of the early diagnosis, since they occurred within the first year. Cognitive slowness and unspecific visual complains are also early symptoms, while usual cardinal signs such as supranuclear palsy are more delayed. Blepharospasm and eyelid opening apraxia as well as deep sighs are also quite characteristic clinical features (1/3 of cases). Cardinal signs (falls, pseudobulbar signs, supranuclear gaze palsy) worsened rapidly (20 to 30 months) towards a major disability. In the 20 patients deceased during follow-up, the mean survival time was about 5 years. The MRI study showed typical cortical fronto-temporo-parietal atrophy, mesencephalic and quadrigeminal plate atrophy with third ventricle dilatation. In conclusion, unexplained falls associated with atypical parkinsonism are contributive for the early clinical diagnosis. Non specific visual complains could be useful pointers in the absence of supranuclear ophthalmoplegia. MRI contributes to the clinical diagnosis even in the first 3 years of the disease course.


Assuntos
Paralisia Supranuclear Progressiva/patologia , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , Cognição/fisiologia , Avaliação da Deficiência , Progressão da Doença , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Paralisia Supranuclear Progressiva/diagnóstico , Paralisia Supranuclear Progressiva/psicologia
20.
Eur J Neurol ; 9(5): 457-62, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12220376

RESUMO

We report the molecular and phenotypic analysis of a French cluster of three cases of Creutzfeldt-Jakob disease (CJD), two of them occurring in 1998 in the same village and the other in 1995 in a neighboring village. Analyses of the occurrence of these events in a close area with less than 3000 inhabitants over the 1992-1999 notification period confirmed that they are rare. This could be explained either by a common source of contamination or by the coincidental occurrence of either sporadic or genetic CJD. We applied genetic analysis and brain PrPres typing to explore these CJD cases. The three patients did not carry any mutation in their prion protein gene coding sequence. All were homozygous for methionine at the polymorphic codon 129. Brain tissue was available from two cases that died in 1998. The two patients showed different PrPres profiles on Western blot and distinct clinico-pathological features. These findings do not support the conclusion that in these three cases, CJD was acquired from a unique source of contamination and suggest that concurrent occurrence of sporadic CJD accounted for this CJD cluster.


Assuntos
Síndrome de Creutzfeldt-Jakob/genética , Mutação/genética , Proteínas PrPSc/genética , Idoso , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Análise por Conglomerados , Códon/genética , Síndrome de Creutzfeldt-Jakob/fisiopatologia , Análise Mutacional de DNA , Feminino , França , Testes Genéticos , Genótipo , Humanos , Masculino , Metionina/genética , Pessoa de Meia-Idade , Polimorfismo Genético/genética , Proteínas PrPSc/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA