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1.
ACS Appl Mater Interfaces ; 16(20): 26521-26536, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38713480

RESUMO

A functionalization process has been developed and the experimental conditions optimized allowing the immobilization of first-row transition metal (Mn+) containing polyoxometalates (POMs) with the formula [M(H2O)P2W17O61](10-n)- on transparent indium-tin oxide (ITO) electrodes for electrochromic applications. Both flat ITO grafted with 4-sulfophenyl moieties and sulfonate-functionalized vertically oriented silica films on ITO have been used as electrode supports to evaluate possible confinement effects provided by the mesoporous matrix on the stability of the modified surfaces and their electrochromic properties. Functionalization involved a two-step sequential process: (i) the immobilization of hexaaqua metallic ions, such as Fe(H2O)63+, onto the sulfonate-functionalized materials achieved through hydrogen bonding interactions between the sulfonate functions and aqua ligands (water molecules) coordinated to the metallic ions facilitating and stabilizing the attachment of the metallic ions to the sulfonated surfaces; (ii) their coordination to [P2W17O61]10- species to generate "in situ" the target [Fe(H2O)P2W17O61]7- moieties. Comparison of the characterized surfaces clearly evidenced a significant improvement in the long-term stability of the nanostructured [Fe(H2O)P2W17O61]7--functionalized silica films compared to the less constrained flat [Fe(H2O)P2W17O61]7--modified ITO electrodes for which a rapid loss of [P2W17O61]10- species was observed. Concordantly, the [Fe(H2O)P2W17O61]7- POM confined in the mesoporous films coated on ITO gave rise to much better and stable electrochromic properties, with a transmittance modulation of 40% at 515 nm.

2.
Int J Mol Sci ; 24(6)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36982686

RESUMO

The study of planar energy storage devices, characterized by low-cost, high capacity, and satisfactory flexibility, is becoming a valuable research hotspot. Graphene, monolayer sp2 hybrid carbon atoms with a large surface area, always acts as its active component, yet there is a tension between its high conductivity and ease of implementation. Although the difficult-to-assemble graphene can easily achieve planar assemblies in its highly oxidized form (GO), the undesirable conductivity, even after proper reduction, still restricts its further applications. Here, a facile "Top-down" method has been proposed to prepare the graphene planar electrode via in situ electro-exfoliation of graphite supported on a piece of laser-cutting patterned scotch tape. Detailed characterizations have been performed to study its physiochemical property evolution during electro-exfoliation. The obtained flexible graphene planar electrodes show decent energy storage performance, e.g., 40.8 mF cm-2 at a current density of 0.5 mA cm-2 and an 81% capacity retention at a current density of 8 mA cm-2 for the optimized sample G-240. Their high conductivity also makes it possible to couple them with other redox-active materials through electrodeposition to improve their performance, e.g., ferrocene-functionalized mesoporous silica film (Fc-MS), MnO2, and polyaniline (PANI). The highest capacity was achieved with the PANI functionalized sample, which achieved a 22-fold capacity increase. In a word, the versatility, practicality, and adaptability of the protocol to prepare the planar graphene electrode proposed in this work make it a potential candidate to meet the continuously growing energy storage demands.


Assuntos
Grafite , Grafite/química , Óxidos/química , Compostos de Manganês/química , Dióxido de Silício , Eletrodos
3.
J Clin Microbiol ; 61(1): e0111022, 2023 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-36602341

RESUMO

Mycobacterium abscessus is one of the most common and pathogenic nontuberculous mycobacteria (NTM) isolated in clinical laboratories. It consists of three subspecies: M. abscessus subsp. abscessus, M. abscessus subsp. bolletii, and M. abscessus subsp. massiliense. Due to their different antibiotic susceptibility pattern, a rapid and accurate identification method is necessary for their differentiation. Although matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has proven useful for NTM identification, the differentiation of M. abscessus subspecies is challenging. In this study, a collection of 325 clinical isolates of M. abscessus was used for MALDI-TOF MS analysis and for the development of machine learning predictive models based on MALDI-TOF MS protein spectra. Overall, using a random forest model with several confidence criteria (samples by triplicate and similarity values >60%), a total of 96.5% of isolates were correctly identified at the subspecies level. Moreover, an improved model with Spanish isolates was able to identify 88.9% of strains collected in other countries. In addition, differences in culture media, colony morphology, and geographic origin of the strains were evaluated, showing that the latter had an impact on the protein spectra. Finally, after studying all protein peaks previously reported for this species, two novel peaks with potential for subspecies differentiation were found. Therefore, machine learning methodology has proven to be a promising approach for rapid and accurate identification of subspecies of M. abscessus using MALDI-TOF MS.


Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Mycobacterium , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Micobactérias não Tuberculosas , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/microbiologia
4.
Front Aging Neurosci ; 14: 936077, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36248000

RESUMO

Background: Post-stroke cognitive and emotional complications are frequent in the chronic stages of stroke and have important implications for the functionality and quality of life of those affected and their caregivers. Strategies such as mindfulness meditation, physical exercise (PE), or computerized cognitive training (CCT) may benefit stroke patients by impacting neuroplasticity and brain health. Materials and methods: One hundred and forty-one chronic stroke patients are randomly allocated to receive mindfulness-based stress reduction + CCT (n = 47), multicomponent PE program + CCT (n = 47), or CCT alone (n = 47). Interventions consist of 12-week home-based programs five days per week. Before and after the interventions, we collect data from cognitive, psychological, and physical tests, blood and stool samples, and structural and functional brain scans. Results: The effects of the interventions on cognitive and emotional outcomes will be described in intention-to-treat and per-protocol analyses. We will also explore potential mediators and moderators, such as genetic, molecular, brain, demographic, and clinical factors in our per-protocol sample. Discussion: The MindFit Project is a randomized clinical trial that aims to assess the impact of mindfulness and PE combined with CCT on chronic stroke patients' cognitive and emotional wellbeing. Furthermore, our design takes a multimodal biopsychosocial approach that will generate new knowledge at multiple levels of evidence, from molecular bases to behavioral changes. Clinical trial registration: www.ClinicalTrials.gov, identifier NCT04759950.

5.
Molecules ; 27(17)2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-36080210

RESUMO

Iron (II) tris(2,2'-bipyridine) complexes, [Fe(bpy)3]2+, have been synthesized and immobilized in organosulfonate-functionalized nanostructured silica thin films taking advantage of the stabilization of [Fe(H2O)6]2+ species by hydrogen bonds to the anionic sulfonate moieties grafted to the silica nanopores. In a first step, thiol-based silica films have been electrochemically generated on indium tin oxide (ITO) substrates by co-condensation of 3-mercaptopropyltrimethoxysilane (MPTMS) and tetraethoxysilane (TEOS). Secondly, the thiol function has been modified to sulfonate by chemical oxidation using hydrogen peroxide in acidic medium as an oxidizing agent. The immobilization of [Fe(bpy)3]2+ complexes has been performed in situ in two consecutive steps: (i) impregnation of the sulfonate functionalized silica films in an aqueous solution of iron (II) sulfate heptahydrate; (ii) dipping of the iron-containing mesostructures in a solution of bipyridine ligands in acetonitrile. The in situ formation of the [Fe(bpy)3]2+ complex is evidenced by its characteristic optical absorption spectrum, and elemental composition analysis using X-ray photoelectron spectroscopy. The measured optical and electrochemical properties of immobilized [Fe(bpy)3]2+ complexes are not altered by confinement in the nanostructured silica thin film.


Assuntos
Complexos de Coordenação , Cátions , Complexos de Coordenação/química , Ferro/química , Ligantes , Dióxido de Silício , Compostos de Sulfidrila
6.
Faraday Discuss ; 233(0): 77-99, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-34889333

RESUMO

Indium-tin oxide electrodes modified with vertically aligned silica nanochannel membranes have been produced by electrochemically assisted self-assembly of cationic surfactants (cetyl- or octadecyl-trimethylammonium bromide) and concomitant polycondensation of the silica precursors (tetraethoxysilane). They exhibited pore diameters in the 2-3 nm range depending on the surfactant used. After surfactant removal, the bottom of mesopores was derivatized with aminophenyl groups via electrografting (i.e., electrochemical reduction of in situ generated aminophenyl monodiazonium salt). These species covalently bonded to the ITO substrate were then exploited to grow polyaniline nanofilaments by electropolymerization of aniline through the nanochannels. Under potentiostatic conditions, the length of polyaniline wires is controllable by tuning the electropolymerization time. From cyclic voltammetry characterization performed either before or after dissolution of the silica template, it appeared that both the polyaniline/silica composite and the free polyaniline nanowire arrays were electroactive, yet with much larger peak currents in the latter case as a result of larger effective surface area offered to the electrolyte solution. At identical electropolymerization time, the amount of deposited polyaniline was larger when using the silica membrane with larger pore diameter. All polyaniline deposits exhibited electrochromic properties. However, the spectroelectrochemical data indicated more complete interconversion between the coloured oxidized form and colourless reduced polyaniline for the arrays of nanofilaments in comparison to bulky films. In addition, the template-free nanowire arrays (i.e., after silica dissolution) were characterized by faster electrochromic behaviour than the polyaniline/silica hybrid, confirming the potential interest of such polyaniline nano-brushes for practical applications.

7.
Chemphyschem ; 22(23): 2464-2477, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34708493

RESUMO

Silica matrices hosting transition metal guest complexes may offer remarkable platforms for the development of advanced functional devices. We report here the elaboration of ordered and vertically oriented mesoporous silica thin films containing covalently attached tris(bipyridine)iron derivatives using a combination of electrochemically assisted self-assembly (EASA) method and Huisgen cycloaddition reaction. Such a versatile approach is primarily used to bind nitrogen-based chelating ligands such as (4-[(2-propyn-1-yloxy)]4'-methyl-2,2'-bypiridine, bpy') inside the nanochannels. Further derivatization of the bpy'-functionalized silica thin films is then achieved via a subsequent in-situ complexation step to generate [Fe(bpy)2 (bpy')]2+ inside the mesopore channels. After giving spectroscopic evidences for the presence of such complexes in the functionalized film, electrochemistry is used to transform the confined diamagnetic (S=0) FeLSbpy2bpy'2+ species to paramagnetic (S=1/2) oxidized FeLSbpy2bpy'3+ species in a reversible way, while blue light irradiation (λ=470 nm) enables populating the short-lived paramagnetic (S=2) FeHSbpy2bpy'2+ excited state. [Fe(bpy)2 (bpy')]2+ -functionalized ordered films are therefore both electro- and photo-active through the manipulation of the oxidation state and spin state of the confined complexes, paving the way for their integration in optoelectronic devices.

8.
Int J Mol Sci ; 22(14)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34299121

RESUMO

In this work, we have developed a chemical procedure enabling the preparation of highly ordered and vertically aligned mesoporous silica films containing selected contents of silver ions bonded inside the mesopore channels via anchoring propyl-carboxyl units. The procedure involves the electrochemically assisted self-assembly co-condensation of tetraethoxysilane and (3-cyanopropyl)triethoxysilane in the presence of cetyltrimethylammonium bromide as a surfactant, the subsequent hydrolysis of cyano groups into carboxylate ones, followed by their complexation with silver ions. The output materials have been electrochemically characterized with regard to the synthesis effectiveness in order to confirm and quantify the presence of the silver ions in the material. The mesostructure has been observed by transmission electron microscopy. We have pointed out that it is possible to finely tune the functionalization level by controlling the co-condensation procedure, notably the concentration of (3-cyanopropyl)triethoxysilane in the synthesis medium.


Assuntos
Dióxido de Silício/síntese química , Prata/química , Tensoativos/química , Cetrimônio/química , Porosidade
9.
Front Chem ; 8: 830, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33094099

RESUMO

Recent and potential applications of electrochromic materials include smart windows, optoelectronic devices, and energy conversion. In this study, we have incorporated bis(terpyridine) iron (II) complexes into vertically-oriented silica thin films deposited on indium-tin oxide (ITO) and their electrochromic behavior has been investigated. If 2,2':6',2″-terpyridine is commonly used as a ligand for forming metallo-supramolecular assemblies, with the objective to get metal-terpyridine complexes with multiple stable redox states, their simple and reliable arrangement into linear structures enabling effective electronic communication is however more challenging. We propose to overcome this difficulty by generating such complexes within vertical nanochannels on electrode. Terpyridine ligands were firstly immobilized by combining a click chemistry azide/alkyne approach with an electrochemically-assisted self-assembly (EASA) method used to grow an oriented mesoporous silica membrane bearing azide groups which were further derivatized with 4'-ethynyl-terpyridine ligands. The resulting terpyridine-functionalized films were consecutively dipped in an aqueous solution of Fe(BF4)2 and then in a solution of terpyridine in acetonitrile to form the bis(terpyridine) iron (II) complexes in situ. The electrochromic properties of the films functionalized at various levels were examined by monitoring the changes in their UV/Vis spectra upon electrochemical oxidation at controlled potential of +1.2 V vs. Ag/AgCl. Due to facile charge delocalization during the Fe2+ to Fe3+ redox process, the bis(terpyridine) iron (II) functionalized silica films exhibited electrochromic properties by changing from violet to non-colored using TBABF4 in acetonitrile as an electrolyte. The bis(terpyridine) iron(II) film experienced reversible electrochromic switching by applying +0.5 V in a reverse reduction electrochemical process. The Fe(tpy)2-functionalized silica thin films displayed a good contrast ratio (ΔT%) of 47% and relatively high coloration efficiency (CE) of about 245 cm2/C with a response time of coloring and bleaching of a few seconds (< 4 s).

10.
ACS Appl Mater Interfaces ; 12(21): 24262-24270, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32366093

RESUMO

Organic-inorganic hybrid membranes, made of a high density of redox active moieties covalently bonded to the internal surfaces of vertically aligned mesoporous silica thin films, are relevant for applications in transparent energy storage devices. This is demonstrated here on the basis of functionalized transparent mesoporous silica thin films prepared on the indium-tin oxide electrode from the combination of an electrochemically induced self-assembly method (to generate azide-functionalized silica) and a copper-catalyzed azide-alkyne click reaction (to derivatize the material with electroactive groups). The very small thickness (105 nm) and the uniformly distributed vertical mesochannels with ultranarrow diameter (2 nm) make the hybrid film a promising substrate that not only achieves a transparency of 82% but also provides large surface area to accommodate a high density of redox active species such as ferrocene. In such rigid and insulating porous membranes, the charge transfer reactions take place through a pure electron-hopping mechanism between adjacent redox sites, which are favored by the ordered and oriented mesostructure containing large amounts of uniformly distributed ferrocene functions in the mesochannels. Their performance results from both high charge transfer rates (electron hopping) and easy mass transport (fast diffusion of counter ions). The most effective system is the ferrocene-functionalized silica film prepared from 40% organosilane, which is able to deliver a capacity of 105 C cm-3 (1.10 mC cm-2) at a current density of 0.4 A cm-3 (with up to 48% capacity retention achieved at a charging time as short as 2.8 s). Such an electrode can be associated to an electrodeposited graphene anode in a solid-state battery-capacitor hybrid device, which can deliver 0.74 mC cm-2 at a potential scan rate of 20 mV s-1. The azide-functionalized mesoporous silica film is actually a versatile platform that can be functionalized with different redox molecules, as shown here for cobaltocenium moieties, which may broaden its application field.

11.
Health Informatics J ; 26(1): 45-55, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-30488752

RESUMO

OBJECTIVE: To evaluate the usefulness of YouTube videos as an educative tool for type 2 diabetes self-management. DESIGN: Search terms were "diabetes diet" and "diabetes treatment." Videos were jointly assessed by two reviewers. A third investigator evaluated a random sample to check for agreement. MAIN MEASURES: Usefulness defined as making reference to AAD7 Self-Care Behaviors™ and presence of misleading information. RESULTS: Of the 393 videos included, 42.2 percent (n = 166) classified as "alternative medicine." 40.2 percent (n = 158) contained useful information. 25.7 percent (n = 101) videos contained misleading information. Videos displaying "alternative medicine" professionals (60 out of 200) were less useful (17% vs 57%; p < 0.001) and more misleading (40% vs 2%; p < 0.001). CONCLUSION: The probability of finding videos that relate to AADE7™ self-care behaviors is below 50 percent. The odds of finding misleading information are high. Therefore, it is inadvisable for professionals to recommend the use of YouTube as an educating tool if specific videos are not suggested.


Assuntos
Diabetes Mellitus Tipo 2 , Educação de Pacientes como Assunto , Mídias Sociais , Gravação em Vídeo , Comunicação , Diabetes Mellitus Tipo 2/terapia , Humanos , Educação de Pacientes como Assunto/métodos , Educação de Pacientes como Assunto/normas , Mídias Sociais/normas , Mídias Sociais/estatística & dados numéricos , Gravação em Vídeo/normas , Gravação em Vídeo/estatística & dados numéricos
12.
Molecules ; 24(13)2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31261814

RESUMO

Electronics, and nanoelectronics in particular, represent one of the most promising branches of technology. The search for novel and more efficient materials seems to be natural here. Thus far, silicon-based devices have been monopolizing this domain. Indeed, it is justified since it allows for significant miniaturization of electronic elements by their densification in integrated circuits. Nevertheless, silicon has some restrictions. Since this material is applied in the bulk form, the miniaturization limit seems to be already reached. Moreover, smaller silicon-based elements (mainly processors) need much more energy and generate significantly more heat than their larger counterparts. In our opinion, the future belongs to nanostructured materials where a proper structure is obtained by means of bottom-up nanotechnology. A great example of a material utilizing nanostructuring is mesoporous silica, which, due to its outstanding properties, can find numerous applications in electronic devices. This focused review is devoted to the application of porous silica-based materials in electronics. We guide the reader through the development and most crucial findings of porous silica from its first synthesis in 1992 to the present. The article describes constant struggle of researchers to find better solutions to supercapacitors, lower the k value or redox-active hybrids while maintaining robust mechanical properties. Finally, the last section refers to ultra-modern applications of silica such as molecular artificial neural networks or super-dense magnetic memory storage.


Assuntos
Nanoestruturas/química , Dióxido de Silício/química , Equipamentos e Provisões Elétricas , Porosidade
13.
J Transl Med ; 17(1): 48, 2019 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-30777085

RESUMO

BACKGROUND AND AIMS: Obesity is associated with impaired glucose tolerance which is a risk factor for cardiovascular risk. However, the oral glucose tolerance test (OGTT) is not usually performed in patients with normal fasting glycaemia, thus offering false reassurance to patients with overweight or obesity who may have post-prandial hyperglycaemia. As an alternative to resource demanding OGTTs, we aimed to examine the predictive value of anthropometric measures of total and central fat distribution for post-prandial hyperglycaemia in patients with overweight and obesity with normal fasting glycaemia enrolled in the DICAMANO study. METHODS: We studied 447 subjects with overweight/obesity with a fasting glucose value ≤ 5.5 mmol l-1 (99 mg dl-1) and BMI ≥ 25 kg/m2 who underwent a 75-g OGTT. Post-prandial hyperglycaemia was defined as a glucose level ≥ 7.8 mmol l-1 (140 mg dl-1) 2-h after the OGTT. The anthropometric measurements included body mass index, body adiposity index, waist circumference, neck circumference, waist-to-hip ratio and waist-to-height ratio. RESULTS: The prevalence of post-prandial hyperglycaemia was 26%. Mean 1-h OGTT glucose levels, insulin resistance and beta cell dysfunction was higher in those subjects in the highest tertile for each anthropometric measurement, irrespective of fasting glucose level. Central fat depot anthropometric measurements were strongly and independently associated with an increased risk of post-prandial hyperglycaemia. After multivariable-adjustment for fasting plasma glucose level, smoking, and physical activity level, the odds ratio (95% confidence intervals) for the presence of post-prandial hyperglycaemia for neck circumference, waist circumference and waist-to-height ratio were 3.3 (1.4, 7.7), 2.4 (1.4, 4.4) and 2.5 (1.4, 4.5), respectively. CONCLUSIONS: In this large and comprehensively phenotyped cohort, one in four subjects had post-prandial hyperglycaemia despite normal fasting glycaemia. Anthropometric indices of central fat distribution were strongly and independently associated with an increased risk of post-prandial hyperglycaemia. These results support the association between central adiposity and glucose derangements and demonstrate the clinical usefulness of anthropometric measurements as screening tools for the selection of patients who are most likely to benefit from an OGTT. Trial registration ClinicalTrials.gov Identifier: NCT03506581. Registered 24 April 2018-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03506581.


Assuntos
Adiposidade , Antropometria , Glicemia/metabolismo , Jejum/sangue , Hiperglicemia/sangue , Período Pós-Prandial , Humanos
14.
Sci Rep ; 7(1): 17752, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29259182

RESUMO

The formation of copper atomic contacts has been investigated. Copper nanowires were grown by electrochemical deposition, in the scanning electrochemical microscopy (SECM) configuration, from a platinum microelectrode to an indium tin oxide (ITO) substrate. Self-termination leaves copper filaments between the two electrodes with an atomic point contact at the ITO electrode. Histogram analysis shows that the conductance of this contact is close to, or less than, 1 G0. Atomic contacts were also fabricated on ITO electrodes covered with vertically-aligned mesoporous silica films. Scanning Transmission Electron Microscopy images show that copper filaments occupy individual isolated nanopores. Contacts generated on bare ITO break down rapidly in sodium salicylate, whereas those generated in ITO/nanopores are unaffected; the nanopores protect the copper filaments. Finally, atomic switch behaviour was obtained using these ITO and ITO/nanopores electrodes.

15.
Langmuir ; 33(17): 4224-4234, 2017 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-28398065

RESUMO

The growth of vertically aligned and ordered polyaniline nanofilaments is controlled by potentiostatic polymerization through hexagonally packed and oriented mesoporous silica films. In such small pore template (2 nm in diameter), quasi-single PANI chains are likely to be produced. From chronoamperometric experiments and using films of various thicknesses (100-200 nm) it is possible to evidence the electropolymerization transients, wherein each stage of polymerization (induction period, growth, and overgrowth of polyaniline on mesoporous silica films) is clearly identified. The advantageous effect of mesostructured silica thin films as hard templates for the generation of isolated polyaniline nanofilaments is demonstrated from enhancement of the reversibility between the conductive and the nonconductive states of polyaniline and the higher electroactive surface areas displayed for all mesoporous silica/PANI composites. The possibility to control and tailor the growth of conducting polymer nanofilaments offers numerous opportunities for applications in various fields including energy, sensors and biosensors, photovoltaics, nanophotonics, or nanoelectronics.

16.
J Clin Endocrinol Metab ; 101(10): 3803-3811, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27472196

RESUMO

CONTEXT: Angiopoietin-like protein 8 (ANGPTL8)/betatrophin is a secreted protein initially involved in ß-cell replication. Recent data in humans and mice models suggest that ANGPTL8/betatrophin is more related to lipid metabolism. OBJECTIVE: The aim of the present study was to compare the circulating concentrations of ANGPTL8/betatrophin in individuals with dyslipidemia defined as having high or low levels of high-density lipoprotein (HDL)-cholesterol or triglycerides, respectively. DESIGN, SETTING, AND PARTICIPANTS: Serum concentrations of ANGPTL8/betatrophin were measured by an ELISA in 177 subjects. We studied two different selected case-control dyslipidemic cohorts including individuals with high (n = 43) or low (n = 46) circulating concentrations of HDL-cholesterol or with low (n = 48) or high (n = 40) levels of triglycerides. RESULTS: Circulating concentrations of ANGPTL8/betatrophin were significantly lower in individuals with dyslipidemia (P < .001) in both males (controls 27.8 ± 15.2 vs dyslipidemic 17.0 ± 11.2 ng/mL) and females (controls 50.0 ± 22.2 vs dyslipidemic 27.0 ± 16.5 ng/mL). The magnitude of the differences was higher in dyslipidemic patients with low HDL-cholesterol than in those with high triglyceride concentrations. ANGPTL8/betatrophin levels were lower in subjects with type 2 diabetes (P < .001), but the impact of type 2 diabetes vanished (P = .257) when the effect of dyslipidemia was included in the analysis. CONCLUSIONS: We conclude that serum ANGPTL8/betatrophin concentrations are altered in human dyslipidemia. ANGPTL8/betatrophin emerges as a potential player in dyslipidemia with a strong association with HDL-cholesterol and a potential therapeutic tool for the treatment of dyslipidemia.


Assuntos
HDL-Colesterol/sangue , Diabetes Mellitus Tipo 2/sangue , Dislipidemias/sangue , Metabolismo dos Lipídeos , Hormônios Peptídicos/sangue , Triglicerídeos/sangue , Adulto , Proteína 8 Semelhante a Angiopoietina , Proteínas Semelhantes a Angiopoietina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
ACS Appl Mater Interfaces ; 8(27): 17591-8, 2016 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-27299176

RESUMO

Thiol-ene click chemistry can be exploited for the immobilization of cysteine-tagged dehydrogenases in an active form onto carbon electrodes (glassy carbon and carbon felt). The electrode surfaces have been first modified with vinylphenyl groups by electrochemical reduction of the corresponding diazonium salts generated in situ from 4-vinylaniline. The grafting process has been optimized in order to not hinder the electrochemical regeneration of NAD(+)/NADH cofactor and soluble mediators such as ferrocenedimethanol and [Cp*Rh(bpy)Cl](+). Having demonstrated the feasibility of thiol-ene click chemistry for attaching ferrocene moieties onto those carbon surfaces, the same approach was then applied to the immobilization of d-sorbitol dehydrogenases with cysteine tag. These proteins can be effectively immobilized (as pointed out by XPS), and the cysteine tag (either 1 or 2 cysteine moieties at the N terminus of the polypeptide chain) was proven to maintain the enzymatic activity of the dehydrogenase upon grafting. The bioelectrode was applied to electroenzymatic enantioselective reduction of d-fructose to d-sorbitol, as a case study.


Assuntos
Química Click , Cisteína , Eletrodos , Oxirredutases , Compostos de Sulfidrila
18.
Langmuir ; 32(17): 4323-32, 2016 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-27065214

RESUMO

Vertically oriented mesoporous silica has proven to be of interest for applications in a variety of fields (e.g., electroanalysis, energy, and nanotechnology). Although glassy carbon is widely used as an electrode material, the adherence of silica deposits is rather poor, causing mechanical instability. A solution to improve the adhesion of mesoporous silica films onto glassy carbon electrodes without compromising the vertical orientation and the order of the mesopores will greatly contribute to the use of this kind of modified carbon electrode. We propose here the electrografting of 3-aminopropyltriethoxysilane on glassy carbon as a molecular glue to improve the mechanical stability of the silica film on the electrode surface without disturbing the vertical orientation and the order of the mesoporous silica obtained by electrochemically assisted self-assembly. These findings are supported by a series of surface chemistry techniques such as X-ray photoelectron spectroscopy, scanning and transmission electron microscopy, and cyclic voltammetry. Finally, methylviologen was used as a model redox probe to investigate the cathodic potential region of both glassy carbon and indium tin oxide electrodes modified with mesoporous silica in order to demonstrate further the interest in the approach developed here.

19.
Chemistry ; 21(1): 455-67, 2015 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-25358895

RESUMO

A series of photochromic derivatives based on the trans-10b,10c-dimethyl-10b,10c-dihydropyrene (DHP, "closed form") skeleton has been synthesized and their photoisomerization leading to the corresponding cyclophanediene (CPD, "open form") isomers has been investigated by UV/Vis and (1) H NMR spectroscopies. Substitution of the DHP core with electron-withdrawing pyridinium groups was found to have major effects on the photoisomerization efficiency, the most remarkable examples being to enhance the quantum yield of the opening reaction and to allow fast and quantitative conversions at much lower radiant energies. This effect was rationalized by theoretical calculations. We also show that the reverse reaction, that is, going from the open form to the closed form, can be electrochemically triggered by oxidation of the CPD unit and that the photo-opening properties of pyridine-substituted DHPs can be efficiently tuned by protonation, the system behaving as a multi-addressable molecular switch. These multi-addressable photochromes show promise for the development of responsive materials.

20.
Diabetes Care ; 37(10): 2813-21, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25011950

RESUMO

OBJECTIVE: It has been suggested that individuals with the condition known as metabolically healthy obesity (MHO) may not have the same increased risk for the development of metabolic abnormalities as their non-metabolically healthy counterparts. However, the validity of this concept has recently been challenged, since it may not translate into lower morbidity and mortality. The aim of the current study was to compare the cardiometabolic/inflammatory profile and the prevalence of impaired glucose tolerance (IGT) and type 2 diabetes (T2D) in patients categorized as having MHO or metabolically abnormal obesity (MAO). RESEARCH DESIGN AND METHODS: We performed a cross-sectional analysis to compare the cardiometabolic/inflammatory profile of 222 MHO and 222 MAO patients (62% women) matched by age, including 255 lean subjects as reference (cohort 1). In a second cohort, we analyzed the adipokine profile and the expression of genes involved in inflammation and extracellular matrix remodeling in visceral adipose tissue (VAT; n = 82) and liver (n = 55). RESULTS: The cardiometabolic and inflammatory profiles (CRP, fibrinogen, uric acid, leukocyte count, and hepatic enzymes) were similarly increased in MHO and MAO in both cohorts. Moreover, above 30%of patients classified as MHO according to fasting plasma glucose exhibited IGT or T2D [corrected]. The profile of classic (leptin, adiponectin, resistin) as well as novel (serum amyloid A and matrix metallopeptidase 9) adipokines was almost identical in MHO and MAO groups in cohort 2. Expression of genes involved in inflammation and tissue remodeling in VAT and liver showed a similar alteration pattern in MHO and MAO individuals. CONCLUSIONS: The current study provides evidence for the existence of a comparable adverse cardiometabolic profile in MHO and MAO patients; thus the MHO concept should be applied with caution. A better identification of the obesity phenotypes and a more precise diagnosis are needed for improving the management of obese individuals.


Assuntos
Doenças Cardiovasculares/etiologia , Inflamação/etiologia , Gordura Intra-Abdominal , Doenças Metabólicas/etiologia , Obesidade/complicações , Obesidade/epidemiologia , Adulto , Idoso , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/metabolismo , Estudos de Casos e Controles , Estudos Transversais , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/etiologia , Feminino , Intolerância à Glucose/epidemiologia , Intolerância à Glucose/etiologia , Humanos , Inflamação/epidemiologia , Inflamação/metabolismo , Gordura Intra-Abdominal/imunologia , Gordura Intra-Abdominal/metabolismo , Fígado/imunologia , Fígado/metabolismo , Masculino , Doenças Metabólicas/epidemiologia , Doenças Metabólicas/metabolismo , Pessoa de Meia-Idade , Obesidade/classificação , Obesidade/metabolismo , Prevalência , Fatores de Risco , Adulto Jovem
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