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1.
J Occup Environ Hyg ; 20(5-6): 183-206, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37104117

RESUMO

Workers, particularly outdoor workers, are among the populations most disproportionately affected by climate-related hazards. However, scientific research and control actions to comprehensively address these hazards are notably absent. To assess this absence, a seven-category framework was developed in 2009 to characterize the scientific literature published from 1988-2008. Using this framework, a second assessment examined the literature published through 2014, and the current one examines literature from 2014-2021. The objectives were to present literature that updates the framework and related topics and increases awareness of the role of climate change in occupational safety and health. In general, there is substantial literature on worker hazards related to ambient temperatures, biological hazards, and extreme weather but less on air pollution, ultraviolet radiation, industrial transitions, and the built environment. There is growing literature on mental health and health equity issues related to climate change, but much more research is needed. The socioeconomic impacts of climate change also require more research. This study illustrates that workers are experiencing increased morbidity and mortality related to climate change. In all areas of climate-related worker risk, including geoengineering, research is needed on the causality and prevalence of hazards, along with surveillance to identify, and interventions for hazard prevention and control.


Assuntos
Exposição Ocupacional , Saúde Ocupacional , Humanos , Mudança Climática , Raios Ultravioleta/efeitos adversos , Exposição Ocupacional/análise
2.
Small ; 16(12): e1903753, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31565857

RESUMO

Colloidal liquid metal alloys of gallium, with melting points below room temperature, are potential candidates for creating electrically conductive and flexible composites. However, inclusion of liquid metal micro- and nanodroplets into soft polymeric matrices requires a harsh auxiliary mechanical pressing to rupture the droplets to establish continuous pathways for high electrical conductivity. However, such a destructive strategy reduces the integrity of the composites. Here, this problem is solved by incorporating small loading of nonfunctionalized graphene flakes into the composites. The flakes introduce cavities that are filled with liquid metal after only relatively mild press-rolling (<0.1 MPa) to form electrically conductive continuous pathways within the polymeric matrix, while maintaining the integrity and flexibility of the composites. The composites are characterized to show that even very low graphene loadings (≈0.6 wt%) can achieve high electrical conductivity. The electrical conductance remains nearly constant, with changes less than 0.5%, even under a relatively high applied pressure of >30 kPa. The composites are used for forming flexible electrically-conductive tracks in electronic circuits with a self-healing property. The demonstrated application of co-fillers, together with liquid metal droplets, can be used for establishing electrically-conductive printable-composite tracks for future large-area flexible electronics.

3.
Mol Psychiatry ; 23(4): 1021-1030, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29565042

RESUMO

The role of astrocytes in brain plasticity has not been extensively studied compared with that of neurons. Here we adopted integrative translational and reverse-translational approaches to explore the role of an astrocyte-specific major water channel in the brain, aquaporin-4 (AQP4), in brain plasticity and learning. We initially identified the most prevalent genetic variant of AQP4 (single nucleotide polymorphism of rs162008 with C or T variation, which has a minor allele frequency of 0.21) from a human database (n=60 706) and examined its functionality in modulating the expression level of AQP4 in an in vitro luciferase reporter assay. In the following experiments, AQP4 knock-down in mice not only impaired hippocampal volumetric plasticity after exposure to enriched environment but also caused loss of long-term potentiation after theta-burst stimulation. In humans, there was a cross-sectional association of rs162008 with gray matter (GM) volume variation in cortices, including the vicinity of the Perisylvian heteromodal language area (Sample 1, n=650). GM volume variation in these brain regions was positively associated with the semantic verbal fluency. In a prospective follow-up study (Sample 2, n=45), the effects of an intensive 5-week foreign language (English) learning experience on regional GM volume increase were modulated by this AQP4 variant, which was also associated with verbal learning capacity change. We then delineated in mice mechanisms that included AQP4-dependent transient astrocytic volume changes and astrocytic structural elaboration. We believe our study provides the first integrative evidence for a gliogenetic basis that involves AQP4, underlying language-associated brain plasticity.


Assuntos
Aquaporina 4/metabolismo , Astrócitos/citologia , Desenvolvimento da Linguagem , Aprendizagem/fisiologia , Neuroglia/citologia , Plasticidade Neuronal/fisiologia , Adulto , Animais , Aquaporina 4/biossíntese , Aquaporina 4/genética , Astrócitos/metabolismo , Encéfalo/metabolismo , Estudos Transversais , Modelos Animais de Doenças , Feminino , Seguimentos , Frequência do Gene , Substância Cinzenta/citologia , Substância Cinzenta/metabolismo , Hipocampo/metabolismo , Humanos , Masculino , Camundongos , Camundongos Knockout , Neuroglia/metabolismo , Neurônios/metabolismo , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos
4.
Am J Hematol ; 94(6): 650-657, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30900772

RESUMO

The present study aimed to define a subtype of complex/monosomal karyotype (CK/MK) acute myeloid leukemia (AML) by its distinct clinical features, p53 signaling and responses to p53 targeting agents. Ninety-eight young adults (range: 21-60 years; median: 49 years) with CK/MK AML were studied. They received standard induction, consolidation and allogeneic hematopoietic stem cell transplantation from siblings or matched unrelated donors if available. Chromosomal abnormalities most commonly affected chromosome 5 (30%), 7 (22%) and 17 (21%). Next generation sequencing of a 54-myeloid gene panel were available in 76 patients. Tumor protein 53 (TP53) mutations were most common (49%) and associated with the presence of -5/5q- (P < .001) and -17/17p- (P < .001), but not -7/7q- (P = .370). This "typical" CK/MK AML subtype was associated with significantly lower presenting white cell counts, higher number of karyotypic abnormalities, and inferior leukemia-free and overall survivals, compared with CK/MK AML without the typical features. Blood or bone marrow samples from typical CK/MK AML patients showed defective p53 signaling upon induction by etoposide. In vitro drug sensitivity analysis showed that they were sensitive to APR-246 that targeted mutant p53, but resistant to MDM2 antagonist MI-77301. Novel therapeutic strategies targeting TP53 mutations in CK/MK AML should be developed and tested in clinical trials.


Assuntos
Cariótipo Anormal , Antineoplásicos/administração & dosagem , Cromossomos Humanos , Resistencia a Medicamentos Antineoplásicos , Leucemia Mieloide Aguda , Monossomia , Proteína Supressora de Tumor p53 , Adolescente , Adulto , Cromossomos Humanos/genética , Cromossomos Humanos/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Masculino , Pessoa de Meia-Idade , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
5.
J Cell Biochem ; 119(2): 1420-1428, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28731226

RESUMO

The regulatory T cells (Treg) play an important role in the tumor tolerance. The methods to regulate the Treg population in cancer-bearing hosts are limited currently. The effect of curcumin on inhibiting cancer has been recognized, but the mechanism remains elusive. This study tests a hypothesis that administration of curcumin down regulates Tregs in lung cancer (LC) patients. In this study, a group of LC patients was treated with curcumin. The peripheral Tregs and T helper (Th) 1 cells were analyzed by flow cytometry. The mechanism by which curcumin regulated the Tregs was observed by cell culture approaches. The results showed that the frequency of peripheral Treg was markedly higher in LC patients than that in healthy subjects, which was suppressed after treating with curcumin for 2 weeks. The peripheral Th1 cells were increased in LC patients after the curcumin therapy. The data of the in vitro experiments showed that curcumin converted the LC patient-isolated Tregs to Th1 cells via repressing the gene transcription of forkhead protein-3 and increasing the expression of interferon-γ. In conclusion, curcumin can convert LC patient-isolated Tregs to Th1 cells. The results suggest that curcumin may improve the antitumor immunity by regulating the tumor specific immune tolerance.


Assuntos
Curcumina/administração & dosagem , Fatores de Transcrição Forkhead/genética , Neoplasias Pulmonares/tratamento farmacológico , Linfócitos T Reguladores/efeitos dos fármacos , Células Th1/efeitos dos fármacos , Adulto , Idoso , Curcumina/farmacologia , Feminino , Fatores de Transcrição Forkhead/metabolismo , Humanos , Interferon gama/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Masculino , Pessoa de Meia-Idade , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/metabolismo , Células Th1/citologia , Células Th1/metabolismo , Células Tumorais Cultivadas
6.
Biochemistry ; 56(26): 3347-3357, 2017 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-28603981

RESUMO

OleT is a cytochrome P450 enzyme that catalyzes the removal of carbon dioxide from variable chain length fatty acids to form 1-alkenes. In this work, we examine the binding and metabolic profile of OleT with shorter chain length (n ≤ 12) fatty acids that can form liquid transportation fuels. Transient kinetics and product analyses confirm that OleT capably activates hydrogen peroxide with shorter substrates to form the high-valent intermediate Compound I and largely performs C-C bond scission. However, the enzyme also produces fatty alcohol side products using the high-valent iron oxo chemistry commonly associated with insertion of oxygen into hydrocarbons. When presented with a short chain fatty acid that can initiate the formation of Compound I, OleT oxidizes the diagnostic probe molecules norcarane and methylcyclopropane in a manner that is reminiscent of reactions of many CYP hydroxylases with radical clock substrates. These data are consistent with a decarboxylation mechanism in which Compound I abstracts a substrate hydrogen atom in the initial step. Positioning of the incipient substrate radical is a crucial element in controlling the efficiency of activated OH rebound.


Assuntos
Proteínas de Bactérias/metabolismo , Caproatos/metabolismo , Caprilatos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Ácidos Decanoicos/metabolismo , Ácidos Láuricos/metabolismo , Micrococcus/enzimologia , Modelos Moleculares , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Biocatálise , Biocombustíveis/análise , Caprilatos/química , Carboxiliases/química , Carboxiliases/genética , Carboxiliases/metabolismo , Domínio Catalítico , Ciclopropanos/química , Ciclopropanos/metabolismo , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/genética , Ácidos Decanoicos/química , Descarboxilação , Guaiacol/metabolismo , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Ácidos Láuricos/química , Conformação Molecular , Oxirredução , Especificidade por Substrato , Terpenos/química , Terpenos/metabolismo
7.
J Biol Inorg Chem ; 22(2-3): 221-235, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28004185

RESUMO

Increasing levels of energy consumption, dwindling resources, and environmental considerations have served as compelling motivations to explore renewable alternatives to petroleum-based fuels, including enzymatic routes for hydrocarbon synthesis. Phylogenetically diverse species have long been recognized to produce hydrocarbons, but many of the enzymes responsible have been identified within the past decade. The enzymatic conversion of Cn chain length fatty aldehydes (or acids) to Cn-1 hydrocarbons, alkanes or alkenes, involves a C-C scission reaction. Surprisingly, the enzymes involved in hydrocarbon synthesis utilize non-heme mononuclear iron, dinuclear iron, and thiolate-ligated heme cofactors that are most often associated with monooxygenation reactions. In this review, we examine the mechanisms of several enzymes involved in hydrocarbon biosynthesis, with specific emphasis on the structural and electronic changes that enable this functional switch.


Assuntos
Enzimas/química , Enzimas/metabolismo , Hidrocarbonetos/metabolismo , Ferro/metabolismo , Hidrocarbonetos/química
8.
Osteoporos Int ; 28(6): 1931-1938, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28255666

RESUMO

Osteopenia and osteoporosis were independent predictive factors for higher atlantoaxial subluxation occurrence in patients with lower body mass index. Our findings suggest that patients with rheumatoid arthritis with osteopenia or osteoporosis, particularly those with lower body mass index (BMI), should be screened regularly to determine the status of their cervical spines. INTRODUCTION: Cervical spine involvement in rheumatoid arthritis (RA) patients may cause serious adverse effects on quality of life and overall health. This study aimed to evaluate the association between atlantodental interval (ADI), atlantoaxial subluxation (AAS), and systemic bone mineral density (BMD) based on BMI variations among established patients with RA. METHODS: The ADI was transformed to the natural log scale to normalize distributions for all analyses. Multivariable linear regression analyses were used to identify independent predictive factors for ADI based on each BMD classification. Multivariate Cox regression analyses were also performed to identify independent predictive factors for the risk of AAS, which were classified by tertile groups of BMI. RESULTS: A total of 1220 patients with RA who had undergone at least one or more cervical radiography and BMD assessments were identified and enrolled. We found that the association between BMD and ADI (ß, -0.029; 95% CI, -0.059 to 0.002; p = 0.070) fell short of achieving statistical significance. However, the ADI showed a 3.6% decrease per 1 BMI increase in the osteoporosis group (ß, -0.036; 95% CI, -0.061 to -0.011; p = 0.004). The osteopenia and osteoporosis groups showed about a 1.5-fold and a 1.8-fold increased risk of AAS occurrence among the first tertile of the BMI group. CONCLUSIONS: Our study showed a possible association between lower BMD and AAS occurrence in patients with RA with lower BMI. Further studies are needed to confirm our findings.


Assuntos
Artrite Reumatoide/complicações , Articulação Atlantoaxial , Densidade Óssea/fisiologia , Doenças Ósseas Metabólicas/complicações , Luxações Articulares/etiologia , Idoso , Antirreumáticos/uso terapêutico , Artrite Reumatoide/sangue , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/fisiopatologia , Índice de Massa Corporal , Doenças Ósseas Metabólicas/fisiopatologia , Vértebras Cervicais , Feminino , Humanos , Luxações Articulares/fisiopatologia , Luxações Articulares/prevenção & controle , Instabilidade Articular/etiologia , Instabilidade Articular/fisiopatologia , Instabilidade Articular/prevenção & controle , Masculino , Pessoa de Meia-Idade , Osteoporose/complicações , Osteoporose/fisiopatologia , Estudos Retrospectivos , Fator Reumatoide/sangue
10.
Intern Med J ; 47(3): 328-332, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28260252

RESUMO

Approximately 40% of patients are non-adherent to their medications. A prospective study of 80 patients evaluated the effectiveness of medical student-led pre-discharge medication education sessions. A significantly greater proportion of patients in the intervention group were adherent to their regular medications at 1 month compared with the control group (76.3% compared to 60.3%, P = 0.037). Medical student-led patient education significantly improved medication adherence rates.


Assuntos
Adesão à Medicação/estatística & dados numéricos , Alta do Paciente , Educação de Pacientes como Assunto , Estudantes de Medicina , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Relações Médico-Paciente , Estudos Prospectivos , Vitória/epidemiologia
11.
Biochem Biophys Res Commun ; 476(4): 462-466, 2016 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-27246733

RESUMO

The efficient hydrogen peroxide-dependent hydroxylation and epoxidation of hydrocarbons is catalysed by a P450 fatty acid decarboxylase (OleT) active-site variant. The introduction of an acidic functionality in the protein framework circumvents the necessity for a carboxylate that is typically provided by the substrate for efficient H2O2 heterolysis. Spectroscopic and turnover studies show that the mutation eliminates the binding and metabolism of prototypical fatty acid substrates, but permits the oxidation of a broad range of inert hydrocarbon substrates.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/metabolismo , Staphylococcaceae/enzimologia , Substituição de Aminoácidos , Proteínas de Bactérias/genética , Domínio Catalítico/genética , Sistema Enzimático do Citocromo P-450/genética , Ácidos Graxos/metabolismo , Peróxido de Hidrogênio/metabolismo , Modelos Moleculares , Mutagênese Sítio-Dirigida , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Staphylococcaceae/genética , Especificidade por Substrato
12.
Breast Cancer Res Treat ; 157(2): 211-215, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27125668

RESUMO

Recently, RECQL was reported as a new breast cancer susceptibility gene. RECQL belongs to the RECQ DNA helicase family which unwinds double strand DNA and involved in the DNA replication stress response, telomere maintenance and DNA repair. RECQL deficient mice cells are prone to spontaneous chromosomal instability and aneuploidy, suggesting a tumor-suppressive role of RECQL in cancer. In this study, RECQL gene mutation screening was performed on 1110 breast cancer patients who were negative for BRCA1, BRCA2, TP53 and PTEN gene mutations and recruited from March 2007 to June 2015 in the Hong Kong Hereditary and High Risk Breast Cancer Program. Four different RECQL pathogenic mutations were identified in six of the 1110 (0.54 %) tested breast cancer patients. The identified mutations include one frame-shift deletion (c.974_977delAAGA), two splicing site mutations (c.394+1G>A, c.867+1G>T) and one nonsense mutation (c.796C>T, p.Gln266Ter). Two of the mutations (c.867+1G>T and p.Gln266Ter) were seen in more than one patients. This study provides the basis for existing of pathogenic RECQL mutations in Southern Chinese breast cancer patients. The significance of rare variants in RECQL gene in the estimation of breast cancer risk warranted further investigation in larger cohort of patients and in other ethnic groups.


Assuntos
Povo Asiático/genética , Neoplasias da Mama/genética , Mutação , RecQ Helicases/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , China , Feminino , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Linhagem , Análise de Sequência de DNA/métodos , Adulto Jovem
13.
Opt Express ; 24(9): 10020-9, 2016 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-27137612

RESUMO

We report free space visible light communication using InGaN sources, namely micro-LEDs and a laser diode, down-converted by a red-emitting AlInGaP multi-quantum-well nanomembrane. In the case of micro-LEDs, the AlInGaP nanomembrane is capillary-bonded between the sapphire window of a micro-LED array and a hemispherical sapphire lens to provide an integrated optical source. The sapphire lens improves the extraction efficiency of the color-converted light. For the case of the down-converted laser diode, one side of the nanomembrane is bonded to a sapphire lens and the other side optionally onto a dielectric mirror; this nanomembrane-lens structure is remotely excited by the laser diode. Data transmission up to 870 Mb/s using pulse amplitude modulation (PAM) with fractionally spaced decision feedback equalizer is demonstrated for the micro-LED-integrated nanomembrane. A data rate of 1.2 Gb/s is achieved using orthogonal frequency division multiplexing (ODFM) with the laser diode pumped sample.

15.
J Opt Soc Am A Opt Image Sci Vis ; 33(9): 1831-5, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27607507

RESUMO

Orbital angular momentum (OAM) entangled photons propagating through non-Kolmogorov turbulence are studied by numerical simulations. Here, the paper uses the multiphase screen model, especially focusing on the influences of the azimuthal mode and the turbulence parameters (i.e., the generalized exponent, the outer scale of turbulence, and the inner scale of turbulence) on entanglement evolution in the weak scintillation regime. The results indicate that the azimuthal mode, the generalized exponent, and the outer scale of turbulence have obvious influences on OAM entanglement. However, the influence of the turbulence inner scale on OAM entanglement can be ignored.

16.
J Card Surg ; 31(3): 174-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26785929

RESUMO

We report the case of a 27-year-old Jehovah's Witness patient with severe pulmonary insufficiency and right ventricular dilatation 16 years after primary repair, who sought transcatheter therapy as a means to avoid surgery and the risk of blood product administration. A hybrid procedure involving pulmonary artery banding to a diameter amenable to fixation of a Melody valve (Medtronic Inc.) via trans-ventricular puncture was performed.


Assuntos
Implante de Prótese de Valva Cardíaca/métodos , Próteses Valvulares Cardíacas , Artéria Pulmonar/cirurgia , Insuficiência da Valva Pulmonar/cirurgia , Valva Pulmonar/cirurgia , Adulto , Dilatação Patológica , Feminino , Ventrículos do Coração/patologia , Humanos , Testemunhas de Jeová , Índice de Gravidade de Doença , Resultado do Tratamento
17.
J Occup Environ Hyg ; 13(11): 847-65, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27115294

RESUMO

In 2009, a preliminary framework for how climate change could affect worker safety and health was described. That framework was based on a literature search from 1988-2008 that supported seven categories of climate-related occupational hazards: (1) increased ambient temperature; (2) air pollution; (3) ultraviolet radiation exposure; (4) extreme weather; (5) vector-borne diseases and expanded habitats; (6) industrial transitions and emerging industries; and (7) changes in the built environment. This article reviews the published literature from 2008-2014 in each of the seven categories. Additionally, three new topics related to occupational safety and health are considered: mental health effects, economic burden, and potential worker safety and health impacts associated with the nascent field of climate intervention (geoengineering). Beyond updating the literature, this article also identifies key priorities for action to better characterize and understand how occupational safety and health may be associated with climate change events and ensure that worker health and safety issues are anticipated, recognized, evaluated, and mitigated. These key priorities include research, surveillance, risk assessment, risk management, and policy development. Strong evidence indicates that climate change will continue to present occupational safety and health hazards, and this framework may be a useful tool for preventing adverse effects to workers.


Assuntos
Mudança Climática , Exposição Ocupacional/análise , Saúde Ocupacional/tendências , Temperatura , Geografia , Humanos , Medição de Risco , Estados Unidos
18.
J Am Chem Soc ; 137(15): 4940-3, 2015 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-25843451

RESUMO

OleT(JE), a cytochrome P450, catalyzes the conversion of fatty acids to terminal alkenes using hydrogen peroxide as a cosubstrate. Analytical studies with an eicosanoic acid substrate show that the enzyme predominantly generates nonadecene and that carbon dioxide is the one carbon coproduct of the reaction. The addition of hydrogen peroxide to a deuterated substrate-enzyme (E-S) complex results in the transient formation of an iron(IV) oxo π cation radical (Compound I) intermediate which is spectroscopically indistinguishable from those that perform oxygen insertion chemistries. A kinetic isotope effect for Compound I decay suggests that it abstracts a substrate hydrogen atom to initiate fatty acid decarboxylation. Together, these results indicate that the initial mechanism for alkene formation, which does not result from oxygen rebound, is similar to that widely suggested for P450 monooxygenation reactions.


Assuntos
Alcenos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Ácidos Graxos/metabolismo , Alcenos/química , Sistema Enzimático do Citocromo P-450/química , Descarboxilação , Ácidos Graxos/química , Estrutura Molecular
19.
Analyst ; 140(3): 889-94, 2015 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-25475046

RESUMO

This work is the further development of the previous pH (effective) sensor work where a biologically derived proton-active redox centre - riboflavin (RFN) - was entrapped into a vapour phase polymerised poly(3,4-ethylenedioxythiophene) film and ferrocene (Fc) dissolved in the sample solution was used as an internal reference redox couple. Here, we report a disposable solid state pH (effective) sensor where we successfully incorporated both RFN and Fc into a single solid state electrode. The electrodes were then used for pH (effective) sensing where water is not required. The system was further miniaturised and simplified from a 3 electrode to a 2 electrode setup with the working electrode area being as small as 0.09 mm(2). The sensors show the ability to measure pH (effective) in both aqueous and non-aqueous media including ionic liquids (ILs) regardless of their hydrophobicity. This is an important step towards the ability to customise ILs or non-aqueous media with suitable proton activity (PA) for various applications e.g. customised ILs for biotechnological applications such as protein preservation and customised media for PA dependent reactions such as catalytic reactions.

20.
J Nanosci Nanotechnol ; 15(7): 4784-91, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26373038

RESUMO

A diamine functionalized cubic mesostructured KIT-6 (N-KIT-6) has been prepared by post-synthetic method using calcined mesoporous KIT-6 with a diamine source, i.e., N-'[3-(tri methoxysilyl)- propyl]'ethylenediamine. The KIT-6 mesoporous silica used for N-KIT-6 was synthesized under weak acidic hydrothermal method using bitemplates, viz., Pluronic P123 and 1-butanol. The synthesized mesoporous materials, KIT-6 and N-KIT-6, have been characterized by the relevant instrumental techniques such as SAXS, N2 sorption isotherm, FT-IR, SEM, TEM and TGA to prove the standard mesoporous materials with the identification of diamine groups. The characterized mesoporous materials, KIT-6 and N-KIT-6, have been extensively used in the potential application of controlled drug delivery, where ibuprofen (IBU) employed as a model drug. The rate of IBU adsorption and release was monitored by UV vis-spectrometer. On the basis of the experimental results of controlled drug delivery system, the results of IBU adsorption and releasing rate in N-KIT-6 are higher than those of KIT-6 because of the higher hydrophobic nature as well as rich basic sites on the surface of inner pore wall silica.


Assuntos
Analgésicos não Narcóticos , Diaminas/química , Ibuprofeno , Dióxido de Silício , Analgésicos não Narcóticos/química , Analgésicos não Narcóticos/farmacocinética , Analgésicos não Narcóticos/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Ibuprofeno/química , Ibuprofeno/farmacocinética , Ibuprofeno/farmacologia , Porosidade , Dióxido de Silício/química , Dióxido de Silício/farmacocinética , Dióxido de Silício/farmacologia
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