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1.
Clin Case Rep ; 11(2): e6760, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36860721

RESUMO

Kyphoscoliotic Ehlers-Danlos syndrome (kEDS) is a rare genetic disorder combining congenital hypotonia, congenital/early onset and progressive kyphoscoliosis, and generalized joint hypermobility. Vascular fragility is another characteristic of the disease rarely described. We report a severe case of kEDS-PLOD1 with several vascular complications leading to difficulties in disease management.

3.
Radiology ; 306(1): 32-46, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36472538

RESUMO

Criteria based on measurements of lesion diameter at CT have guided treatment with historical therapies due to the strong association between tumor size and survival. Clinical experience with immune checkpoint modulators shows that editing immune system function can be effective in various solid tumors. Equally, novel immune-related phenomena accompany this novel therapeutic paradigm. These effects of immunotherapy challenge the association of tumor size with response or progression and include risks and adverse events that present new demands for imaging to guide treatment decisions. Emerging and evolving approaches to immunotherapy highlight further key issues for imaging evaluation, such as dissociated response following local administration of immune checkpoint modulators, pseudoprogression due to immune infiltration in the tumor environment, and premature death due to hyperprogression. Research that may offer tools for radiologists to meet these challenges is reviewed. Different modalities are discussed, including immuno-PET, as well as new applications of CT, MRI, and fluorodeoxyglucose PET, such as radiomics and imaging of hematopoietic tissues or anthropometric characteristics. Multilevel integration of imaging and other biomarkers may improve clinical guidance for immunotherapies and provide theranostic opportunities.


Assuntos
Neoplasias , Humanos , Neoplasias/terapia , Imunoterapia/métodos , Tomografia por Emissão de Pósitrons , Fatores Imunológicos/uso terapêutico , Progressão da Doença
4.
Clin Case Rep ; 10(11): e06338, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36447672

RESUMO

We described a novel de novo missense variant of the gene encoding Collagen alpha-2(V) chain, associated with the classical Ehlers-Danlos syndrome (cEDS) (OMIM#130010), in a 14-year-old patient who presented with congenital and severe scoliosis, muscle hypotonia, ocular manifestations, and no atrophic scaring. This case expands the phenotypic spectrum of cEDS.

5.
Crit Care ; 26(1): 358, 2022 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-36397118

RESUMO

BACKGROUND: A defining feature of prolonged critical illness is muscle wasting, leading to impaired recovery. Supplementation with a tailored blend of amino acids may bolster the innate gut defence, promote intestinal mucosa repair and limit muscle loss. METHODS: This was a monocentric, randomized, double-blind, placebo-controlled study that included patients with sepsis or acute respiratory distress syndrome. Patients received a specific combination of five amino acids or placebo mixed with enteral feeding for 21 days. Markers of renal function, gut barrier structure and functionality were collected at baseline and 1, 2, 3 and 8 weeks after randomization. Muscle structure and function were assessed through MRI measurements of the anterior quadriceps volume and by twitch airway pressure. Data were compared between groups relative to the baseline. RESULTS: Thirty-five critically ill patients were randomized. The amino acid blend did not impair urine output, blood creatinine levels or creatinine clearance. Plasma citrulline levels increased significantly along the treatment period in the amino acid group (difference in means [95% CI] 5.86 [1.72; 10.00] nmol/mL P = 0.007). Alanine aminotransferase and alkaline phosphatase concentrations were lower in the amino acid group than in the placebo group at one week (ratio of means 0.5 [0.29; 0.86] (P = 0.015) and 0.73 [0.57; 0.94] (P = 0.015), respectively). Twitch airway pressure and volume of the anterior quadriceps were greater in the amino acid group than in the placebo group 3 weeks after randomization (difference in means 10.6 [0.99; 20.20] cmH20 (P = 0.035) and 3.12 [0.5; 5.73] cm3/kg (P = 0.022), respectively). CONCLUSIONS: Amino acid supplementation increased plasma citrulline levels, reduced alanine aminotransferase and alkaline phosphatase levels, and improved twitch airway pressure and anterior quadriceps volume. Trial registration ClinicalTrials.gov, NCT02968836. Registered November 21, 2016.


Assuntos
Citrulina , Estado Terminal , Humanos , Estado Terminal/terapia , Creatinina , Fosfatase Alcalina , Alanina Transaminase , Músculos
6.
Molecules ; 27(12)2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35745069

RESUMO

Despite the effectiveness of COVID-19 vaccines, there is still an urgent need for discovering new anti-viral drugs to address the awful spread and transmission of the rapidly modifiable virus. In this study, the ability of a small library of enantiomerically pure spirooxindolopyrrolidine-grafted piperidones to inhibit the main protease of SARS-CoV-2 (Mpro) is evaluated. These spiroheterocycles were synthesized by 1,3-dipolar cycloaddition of various stabilized azomethine ylides with chiral dipolarophiles derived from N-[(S)-(-)-methylbenzyl]-4-piperidone. The absolute configuration of contiguous carbons was confirmed by a single crystal X-ray diffraction analysis. The binding of these compounds to SARS-CoV-2 Mpro was investigated using molecular docking and molecular dynamics simulation. Three compounds 4a, 4b and 4e exhibited stable binding modes interacting with the key subsites of the substrate-binding pocket of SARS-CoV-2 Mpro. The synthesized compounds represent potential leads for the development of novel inhibitors of SARS-CoV-2 main protease protein for COVID-19 treatment.


Assuntos
Tratamento Farmacológico da COVID-19 , Piperidonas , Antivirais/química , Antivirais/farmacologia , Vacinas contra COVID-19 , Cisteína Endopeptidases/química , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Inibidores de Proteases/química , SARS-CoV-2 , Proteínas não Estruturais Virais/metabolismo
7.
Clin Case Rep ; 9(9): e04128, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34484741

RESUMO

COL1-related overlap disorder is a condition, which is not yet considered as part of the 2017 EDS classification. However, it should be investigated as an alternative diagnosis for any patient with hypermobile EDS. This could allow providing appropriate genetic counseling.

8.
Eur Radiol ; 31(12): 9380-9389, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33993328

RESUMO

OBJECTIVES: To evaluate the diagnostic performance and interobserver agreement of a magnetic resonance imaging (MRI) protocol that only includes sagittal T2-weighted Dixon fat and water images as an alternative to a standard protocol that includes both sagittal T1-weighted sequence and T2-weighted Dixon water images as reference standard in lumbar degenerative disc disease with Modic changes. METHODS: From February 2017 to March 2019, 114 patients who underwent lumbar spine MRI for low back pain were included in this retrospective study. All MRI showed Modic changes at least at one vertebral level. Two radiologists read the standard protocol and 1 month later the alternative protocol. All MRI were assessed for Modic changes (types, location, extension) as well as structural changes (endplate defects, facet arthropathy, spinal stenosis, foraminal stenosis, Schmorl nodes, spondylolisthesis, disc bulges, and degeneration). Interobserver agreement was assessed, as well as diagnostic performance using the standard protocol as reference standard. RESULTS: Interobserver agreement was moderate to excellent (kappa ranging from 0.51 to 0.92). Diagnostic performance of the alternative protocol was good for detection of any Modic change (sensitivity = 100.00% [95% CI, 99.03-100.00]; specificity = 98.89% [95% CI, 98.02-99.44]), as well as for detection of each Modic subtype and structural variables (sensitivity respectively 100% and ranging from 88.43 to 99.75% ; specificity ranging respectively from 97.62 to 100% and 99.58 to 99.91% ). CONCLUSIONS: Combined with T2-weighted Dixon water images, T2-weighted Dixon fat images provide good diagnostic performance compared to T1-weighted images in lumbar degenerative disc disease with Modic changes, and could therefore allow for a shortened protocol. KEY POINTS: • Combined with T2-weighted Dixon water images, T2-weighted Dixon fat images (in comparison to T1-weighted sequence) can provide good diagnostic performance in lumbar degenerative disc disease with Modic changes. • Interobserver agreement of the alternative protocol including sagittal T2-weighted Dixon fat and water images was substantial to excellent for every studied variable except for facet arthropathy. • A shortened MRI protocol including T2-weighted Dixon sequence without T1-weighted sequence could be proposed in this clinical setting.


Assuntos
Degeneração do Disco Intervertebral , Deslocamento do Disco Intervertebral , Humanos , Degeneração do Disco Intervertebral/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Imageamento por Ressonância Magnética , Estudos Retrospectivos
9.
Med Image Anal ; 67: 101860, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33171345

RESUMO

Coronavirus disease 2019 (COVID-19) emerged in 2019 and disseminated around the world rapidly. Computed tomography (CT) imaging has been proven to be an important tool for screening, disease quantification and staging. The latter is of extreme importance for organizational anticipation (availability of intensive care unit beds, patient management planning) as well as to accelerate drug development through rapid, reproducible and quantified assessment of treatment response. Even if currently there are no specific guidelines for the staging of the patients, CT together with some clinical and biological biomarkers are used. In this study, we collected a multi-center cohort and we investigated the use of medical imaging and artificial intelligence for disease quantification, staging and outcome prediction. Our approach relies on automatic deep learning-based disease quantification using an ensemble of architectures, and a data-driven consensus for the staging and outcome prediction of the patients fusing imaging biomarkers with clinical and biological attributes. Highly promising results on multiple external/independent evaluation cohorts as well as comparisons with expert human readers demonstrate the potentials of our approach.


Assuntos
Inteligência Artificial , COVID-19/diagnóstico por imagem , Pneumonia Viral/diagnóstico por imagem , Biomarcadores/análise , Progressão da Doença , Humanos , Redes Neurais de Computação , Prognóstico , Interpretação de Imagem Radiográfica Assistida por Computador , SARS-CoV-2 , Triagem
10.
J Med Genet ; 58(9): 645-647, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-32900839

RESUMO

Background We report two cases of RASA1-related capillary malformation-arteriovenous malformation (CM-AVM1) syndrome mimicking hereditary haemorrhagic telangiectasia (HHT).Methods and results A 28-year-old man, previously embolised for cerebral arteriovenous malformations (AVMs), presented with epistaxis and typical nasal telangiectasias of HHT. CT scan revealed a large portocaval shunt. The second patient was a 9-year-old girl presenting with cyanosis and several mucocutaneous telangiectasias, similar to those observed in typical cases of HHT. CT scan revealed a huge and complex pulmonary AVM of the right lower lobe and a hepatic AVM within the left lobe. HHT diagnosis was considered possible according to the Curaçao criteria for the two patients, with at least two criteria for each. Genetic tests did not find any mutation in the three classic genes (Endoglin, Activin receptor-like kinase 1 or Mothers against decapentaplegic homolog 4), but identified in both cases an RASA1 mutation, known to cause CM-AVM1 syndrome.Conclusions Pulmonary AVM and portocaval shunt, usually encountered in HHT, have not yet been described in the CM-AVM1 syndrome. RASA1 screening may be considered in case of HHT suspicion, particularly when mutations are not found in the usually affected genes.


Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Mutação , Fenótipo , Telangiectasia Hemorrágica Hereditária/diagnóstico , Telangiectasia Hemorrágica Hereditária/genética , Proteína p120 Ativadora de GTPase/genética , Adulto , Alelos , Biópsia , Criança , Angiografia por Tomografia Computadorizada , Diagnóstico Diferencial , Feminino , Genótipo , Humanos , Masculino , Análise de Sequência de DNA , Avaliação de Sintomas , Tomografia Computadorizada por Raios X
11.
PLoS One ; 15(12): e0243342, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33332360

RESUMO

INTRODUCTION: In numerous countries, large population testing is impossible due to the limited availability of RT-PCR kits and CT-scans. This study aimed to determine a pre-test probability score for SARS-CoV-2 infection. METHODS: This multicenter retrospective study (4 University Hospitals) included patients with clinical suspicion of SARS-CoV-2 infection. Demographic characteristics, clinical symptoms, and results of blood tests (complete white blood cell count, serum electrolytes and CRP) were collected. A pre-test probability score was derived from univariate analyses of clinical and biological variables between patients and controls, followed by multivariate binary logistic analysis to determine the independent variables associated with SARS-CoV-2 infection. RESULTS: 605 patients were included between March 10th and April 30th, 2020 (200 patients for the training cohort, 405 consecutive patients for the validation cohort). In the multivariate analysis, lymphocyte (<1.3 G/L), eosinophil (<0.06 G/L), basophil (<0.04 G/L) and neutrophil counts (<5 G/L) were associated with high probability of SARS-CoV-2 infection but no clinical variable was statistically significant. The score had a good performance in the validation cohort (AUC = 0.918 (CI: [0.891-0.946]; STD = 0.014) with a Positive Predictive Value of high-probability score of 93% (95%CI: [0.89-0.96]). Furthermore, a low-probability score excluded SARS-CoV-2 infection with a Negative Predictive Value of 98% (95%CI: [0.93-0.99]). The performance of the score was stable even during the last period of the study (15-30th April) with more controls than infected patients. CONCLUSIONS: The PARIS score has a good performance to categorize the pre-test probability of SARS-CoV-2 infection based on complete white blood cell count. It could help clinicians adapt testing and for rapid triage of patients before test results.


Assuntos
COVID-19/diagnóstico , COVID-19/genética , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Probabilidade , Estudos Retrospectivos , Sensibilidade e Especificidade
12.
Respir Med ; 175: 106206, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33166904

RESUMO

INTRODUCTION: Covid-19 pneumonia CT extent correlates well with outcome including mortality. However, CT is not widely available in many countries. This study aimed to explore the relationship between Covid-19 pneumonia CT extent and blood tests variations. The objective was to determine for the biological variables correlating with disease severity the cut-off values showing the best performance to predict the parenchymal extent of the pneumonia. METHODS: Bivariate correlations were calculated between biological variables and grade of disease extent on CT. Receiving Operating Characteristic curve analysis determined the best cutoffs for the strongest correlated biological variables. The performance of these variables to predict mild (<10%) or severe pneumonia (>50% of parenchyma involved) was evaluated. RESULTS: Correlations between biological variables and disease extent was evaluated in 168 patients included in this study. LDH, lymphocyte count and CRP showed the strongest correlations (with 0.67, -0.41 and 0.52 correlation coefficient, respectively). Patients were split into a training and a validation cohort according to their centers. If one variable was above/below the following cut-offs, LDH>380, CRP>80 or lymphocyte count <0.8G/L, severe pneumonia extent on CT was detected with 100% sensitivity. Values above/below all three thresholds were denoted in 73% of patients with severe pneumonia extent. The combination of LDH<220 and CRP<22 was associated with mild pneumonia extent (<10%) with specificity of 100%. DISCUSSION: LDH showed the strongest correlation with the extent of Covid-19 pneumonia on CT. Combined with CRP±lymphocyte count, it helps predicting parenchymal extent of the pneumonia when CT scan is not available.


Assuntos
Biomarcadores/sangue , COVID-19/diagnóstico por imagem , COVID-19/metabolismo , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Proteína C-Reativa/metabolismo , COVID-19/epidemiologia , COVID-19/virologia , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , França/epidemiologia , Humanos , L-Lactato Desidrogenase/metabolismo , Contagem de Linfócitos/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/epidemiologia , Pneumonia Viral/patologia , Estudos Retrospectivos , SARS-CoV-2/genética , Sensibilidade e Especificidade , Índice de Gravidade de Doença
13.
Radiol Case Rep ; 15(7): 1054-1057, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32351657

RESUMO

As coronavirus pandemic continue to spread over the world, we have to be aware of potential complications on hospitalized patients. We report a case of a 79-year-old woman with COVID-19 pneumonia complicated by combined arterial and venous thrombosis of upper mesenteric vessels. As unenhanced chest CT scan plays a key role in managing the COVID-19 pandemic, we should pay attention to indirect signs of thrombosis.

14.
Eur J Cancer ; 119: 44-56, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31415986

RESUMO

PURPOSE: New-onset pituitary gland lesions are observed in up to 18% of cancer patients undergoing treatment with immune checkpoint blockers (ICB). We aimed to develop and validate an imaging-based decision-making algorithm for use by the clinician that helps differentiate pituitary metastasis (PM) from ICB-induced autoimmune hypophysitis (HP). MATERIALS AND METHODS: A systematic search was performed in the MEDLINE and EMBASE databases up to October 2018 to identify studies concerning PM and HP in patients treated with cytotoxic T-lymphocyte-associated protein 4 and programmed cell death (ligand) 1. The reference standard for diagnosis was confirmation by histology or response on follow-up imaging. Patients from included studies were randomly assigned to the training set or the validation set. Using machine learning (random forest tree algorithm) with the most-described six imaging and three clinical features, a multivariable prediction model (the signature) was developed and validated for diagnosing PM. Signature performance was evaluated using area under a receiver operating characteristic curves (AUCs). RESULTS: Out of 3174 screened articles, 65 were included totalising 122 patients (HP: 60 pts, PM: 62 pts). Complete radiological data were available in 82 pts (Training: 62 pts, Validation: 20 pts). The signature reached an AUC = 0.91 (0.82, 1.00), P < 10-8 in the training set and AUC = 0.94 (0.80, 1.00), P = 0.001 in the validation set. The signature predicted PM in lesions either ≥ 2 cm in size or < 2 cm if associated with heterogeneous contrast enhancement and cavernous extension. CONCLUSION: An image-based signature was developed with machine learning and validated for differentiating PM from HP. This tool could be used by clinicians for enhanced decision-making in cancer patients undergoing ICB treatment with new-onset, concerning lesions of the pituitary gland.


Assuntos
Algoritmos , Hipofisite Autoimune/diagnóstico , Aprendizado de Máquina , Neoplasias/terapia , Neoplasias Hipofisárias/diagnóstico , Radioimunoterapia/métodos , Hipofisite Autoimune/etiologia , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Antígeno B7-H1/metabolismo , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/imunologia , Antígeno CTLA-4/metabolismo , Diagnóstico Diferencial , Humanos , Neoplasias/imunologia , Neoplasias/patologia , Neoplasias Hipofisárias/secundário , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Curva ROC , Radioimunoterapia/efeitos adversos
15.
Eur J Cancer ; 96: 91-104, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29698933

RESUMO

BACKGROUND: Programmed death receptor-1 blocking antibodies (anti-PD1) are a new standard of care in many cancer types. Patients benefit from improved survival but have the risk of immune-related adverse events (irAE). We evaluated if medical imaging procedures, used for anti-tumour response assessment, can detect irAEs. MATERIALS AND METHODS: All consecutive patients treated with anti-PD1 and with a medical imaging acquisition performed within 2 weeks with irAEs ≥2 were retrospectively included. Data were gathered from June 2014 to February 2017, and a central review was performed. The primary and secondary end-points were i) to evaluate the overall detection rate of irAEs by medical imaging and ii) to provide a comprehensive radiological description of irAEs. RESULTS: Fifty-three patients (31 women, 22 men; average age: 61 years) were included. The primary tumour was melanoma (n = 32), lung cancer (n = 18) and other (n = 3). Patients were treated with nivolumab (n = 27) or pembrolizumab (n = 26). Of 74 medical imaging procedures analysed (ratio = 1.4 medical imaging per patient), 55 irAE were detected. The detection rate was overall: 74% (95 confidence interval: 63-84%), positron emission tomography with 18F-fludeoxyglucose integrated with computed tomography (18F-FDG PET/CT): 83% (n = 10/12), magnetic resonance imaging: 83% (n = 5/6), computed tomography scan: 79% (n = 19/24), ultrasonography: 70% (n = 19/27), standard X-rays: 40% (n = 2/5), lung/mediastinum: 100% (n = 7/7), enterocolitis: 100% (n = 8/8), hypophysitis: 100% (n = 3/3), thyroiditis: 75% (n = 15/20), hepatitis: 67% (n = 2/3), arthralgia or arthritis: 40% (n = 2/5) and pancreas: 28% (n = 2/7). CONCLUSION: Medical imaging detected 74% of irAE in patients treated with anti-PD1. Beyond response assessment, medical imaging can detect irAE and guide towards specific management. We described the most frequent sites and patterns of imaging findings.


Assuntos
Anticorpos Monoclonais Humanizados/efeitos adversos , Antineoplásicos Imunológicos/efeitos adversos , Diagnóstico por Imagem/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Nivolumabe/efeitos adversos , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Adulto , Idoso , Idoso de 80 Anos ou mais , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/imunologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neoplasias/diagnóstico por imagem , Neoplasias/imunologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Valor Preditivo dos Testes , Receptor de Morte Celular Programada 1/imunologia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia Doppler
16.
Adv Colloid Interface Sci ; 225: 16-36, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26299313

RESUMO

This paper reviews the surface modification strategies of a wide range of nanomaterials using aryldiazonium salts. After a brief history of diazonium salts since their discovery by Peter Griess in 1858, we will tackle the surface chemistry using these compounds since the first trials in the 1950s. We will then focus on the modern surface chemistry of aryldiazonium salts for the modification of materials, particularly metallic, semiconductors, metal oxide nanoparticles, carbon-based nanostructures, diamond and clays. The successful modification of sp(2) carbon materials and metals by aryldiazonium salts paved the way to innovative strategies for the attachment of aryl layers to metal oxide nanoparticles and nanodiamonds, and intercalation of clays. Interestingly, diazotized surfaces can easily trap nanoparticles and nanotubes while diazotized nanoparticles can be (electro)chemically reduced on electrode/materials surfaces as molecular compounds. Both strategies provided organized 2D surface assembled nanoparticles. In this review, aryldiazonium salts are highlighted as efficient coupling agents for many types of molecular, macromolecular and nanoparticulate species, therefore ensuring stability to colloids on the one hand, and the construction of composite materials and hybrid systems with robust and durable interfaces/interphases, on the other hand. The last section is dedicated to a selection of patents and industrial products based on aryldiazonium-modified nanomaterials. After nearly 160 years of organic chemistry, diazonium salts have entered a new, long and thriving era for the benefit of materials, colloids, and surface scientists. This tempts us to introduce the terminology of "diazonics" we define as the science and technology of aryldiazonium salt-derived materials.

17.
J Colloid Interface Sci ; 418: 185-92, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24461834

RESUMO

Highly uniform core-shell like multi-walled carbon nanotubes-polyaniline (MWCNT-PANI) nanocomposites were prepared in two steps (i) surface modification of MWCNTs with a 4-aminodiphenylamine group via in situ diazonium generation process; and (ii) polymerization of aniline onto surface modified MWCNTs. This functionalization helped to easily disperse the MWCNTs in acidic solutions; hence it is suitable for the chemical oxidative polymerization of aniline. It was found that MWCNT-PANI nano-composites with higher MWCNTs loading yield PANI chains with more quinoid units than the pure PANI, which results in significant improvement in the conductivity of the composites. This facile approach of synthesizing core-shell nanocomposites highlights the efficiency of the interfacial chemistry of aryl diazonium salts in generating conductive polymer/MWCNT nanocomposites with enhanced conductivity and high surface area.

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