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1.
Dent Traumatol ; 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38651781

RESUMO

BACKGROUND: Despite the exponential growth of mobile device applications in promoting awareness on traumatic dental injuries (TDIs), the overall validity of existing applications in content, engagement, usability, functionality, esthetics, and user perception remains largely uncertain. AIMS: The primary aim was to systematically search and assess the quality, functionality, perceived impact and usability of available applications related to TDIs using the User Version of the Mobile Application Rating Scale (uMARS) and the Coventry, Aberdeen, and London-Revised (CA-LO-RE) scale. A heuristic evaluation was additionally performed. The secondary aim was to categorize existing mobile applications according to their target users, including general population, dentists, dental students, medical healthcare professionals, and researchers. METHODS: A systematic search for dental trauma applications (free and paid) was conducted using the AppStore and Google Play store. Two reviewers independently performed data extraction and quality assessment for all the included applications using uMARS and CA-LO-RE. A user experience architect conducted a heuristic evaluation. RESULTS: Only 6 of the 3061 initially screened applications were eligible for qualitative and quantitative assessments. These applications' average star uMARS rating was 12.5 (standard deviation [SD] 2.6). The mean and SD for the uMARS objective items were as follows: A-engagement (mean 12.1 [SD 3.3]), B-functionality (mean 15.5 [SD 1.4]), C-esthetics (mean 9.5 [SD 2.5]), and D-information (mean 13 [SD 4.5]). The severity rating for the heuristic evaluation criteria was low to moderate for all the included applications, excluding tooth emergencies with a high severity score. CONCLUSION: Despite moderate quality, functionality, user perception, behavioural impact and usability scores, the inclusion of advanced features to "engagement" and "usability" in existing trauma based apps will enhance their purpose. A design-thinking approach coupled with interactive features is recommended for future mobile applications on TDIs.

3.
Biomolecules ; 13(2)2023 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-36830708

RESUMO

The neurosteroid allopregnanolone (ALLO) and pregnanolone (PREG), are equally effective positive allosteric modulators (PAMs) of GABAA receptors. Interestingly, the PAM effects of ALLO are strongly enantioselective, whereas those of PREG are not. This study was aimed at determining the basis for this difference in enantioselectivity. The oocyte electrophysiology studies showed that ent-ALLO potentiates GABA-elicited currents in α1ß3 GABAA receptors with lower potency and efficacy than ALLO, PREG or ent-PREG. The small PAM effect of ent-ALLO was prevented by the α1(Q242L) mutation in the intersubunit neurosteroid binding site between the ß3 and α1 subunits. Consistent with this result, neurosteroid analogue photolabeling with mass spectrometric readout, showed that ent-ALLO binds weakly to the ß3-α1 intersubunit binding site in comparison to ALLO, PREG and ent-PREG. Rigid body docking predicted that ent-ALLO binds in the intersubunit site with a preferred orientation 180° different than ALLO, PREG or ent-PREG, potentially explaining its weak binding and effect. Photolabeling studies did not identify differences between ALLO and ent-ALLO binding to the α1 or ß3 intrasubunit binding sites that also mediate neurosteroid modulation of GABAA receptors. The results demonstrate that differential binding of ent-ALLO and ent-PREG to the ß3-α1 intersubunit site accounts for the difference in enantioselectivity between ALLO and PREG.


Assuntos
Neuroesteroides , Receptores de GABA-A , Receptores de GABA-A/metabolismo , Estereoisomerismo , Pregnanolona/farmacologia , Ácido gama-Aminobutírico
4.
J Med Chem ; 64(18): 13873-13892, 2021 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-34505767

RESUMO

Mitragynine and 7-hydroxymitragynine (7OH) are the major alkaloids mediating the biological actions of the psychoactive plant kratom. To investigate the structure-activity relationships of mitragynine/7OH templates, we diversified the aromatic ring of the indole at the C9, C10, and C12 positions and investigated their G-protein and arrestin signaling mediated by mu opioid receptors (MOR). Three synthesized lead C9 analogs replacing the 9-OCH3 group with phenyl (4), methyl (5), or 3'-furanyl [6 (SC13)] substituents demonstrated partial agonism with a lower efficacy than DAMGO or morphine in heterologous G-protein assays and synaptic physiology. In assays limiting MOR reserve, the G-protein efficacy of all three was comparable to buprenorphine. 6 (SC13) showed MOR-dependent analgesia with potency similar to morphine without respiratory depression, hyperlocomotion, constipation, or place conditioning in mice. These results suggest the possibility of activating MOR minimally (G-protein Emax ≈ 10%) in cell lines while yet attaining maximal antinociception in vivo with reduced opioid liabilities.


Assuntos
Analgésicos Opioides/farmacologia , Receptores Opioides mu/agonistas , Alcaloides de Triptamina e Secologanina/farmacologia , Analgésicos Opioides/efeitos adversos , Analgésicos Opioides/síntese química , Analgésicos Opioides/metabolismo , Animais , Masculino , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Ratos Sprague-Dawley , Receptores Opioides mu/metabolismo , Alcaloides de Triptamina e Secologanina/efeitos adversos , Alcaloides de Triptamina e Secologanina/síntese química , Alcaloides de Triptamina e Secologanina/metabolismo , Relação Estrutura-Atividade
5.
Vet World ; 14(1): 285-291, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33642816

RESUMO

BACKGROUND AND AIM: In recent times, non-aureus staphylococci (NAS) have emerged as the major organisms isolated from mastitis cases in dairy animals, with a predominance of Staphylococcus epidermidis and Staphylococcus chromogenes. As compared to Staphylococcus aureus, much less is known about the molecular types or the spatiotemporal epidemiology of these NAS species. In the present study, randomly amplified polymorphic DNA (RAPD) was employed to detect genetic polymorphisms, intraspecies diversity, and epidemiology of S. chromogenes strains (n=37) isolated from bovine and bubaline mastitis cases in the state of Karnataka. MATERIALS AND METHODS: Thirty-seven S. chromogenes isolates (14 from bovines and 23 from bubaline) isolated from subclinical mastitis cases, from organized and unorganized sectors, were subjected to RAPD typing. Further, methicillin resistance was determined by cefoxitin disk diffusion method. RESULTS: The amplified DNA fragments ranged from 150 to 3000 base pairs and yielded several RAPD profiles. Further analysis using Digital Image Correlation Engine correlation coefficient and UPGMA method showed that the 37 isolates could be classified into 12 distinct RAPD types (A to L) at 62% similarity (D=0.889). Four of the most predominant RAPD types, B, A, C, and E, in that order, and together, represented 65% of the isolates. High diversity was observed among the isolates both within farms and between geographic locations. Most of the isolates exhibited methicillin resistance. This is the first such report from India. CONCLUSION: In the absence of defined multilocus sequence type protocols or sufficient sequences available in the public domain, RAPD can be employed to determine genetic diversity of S. chromogenes isolates.

6.
J Mol Struct ; 1231: 129981, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33518802

RESUMO

The recent global pandemic caused by COVID-19 has triggered an intense effort worldwide towards the development of an effective cure for this disease. In our effort we have explored the 2-alkynyl substituted 3-chloropyrazine framework as a potential template for the design of molecules for this purpose. Our strategy was supported by the in silico studies of representative compounds to assess their binding affinities via docking into the N-terminal RNA-binding domain (NTD) of N-protein of SARS-CoV-2. Thus we created a small library of molecules based on the aforementioned template via an environmentally safer method that involved the rapid synthesis of 2-alkynyl 3-chloropyrazine derivatives under Cu-catalysis assisted by ultrasound. The reactions proceeded via the coupling of 2,3-dichloropyrazine with commercially available terminal alkynes in the presence of CuI, PPh3 and K2CO3 in PEG-400. Further molecular modelling studies helped in establishing a virtual SAR (Structure Activity Relationship) within the series and identification of three potential hits. The desirable ADME was also predicted for these three molecules suggesting their prospective medicinal value.

7.
ACS Omega ; 5(50): 32349-32356, 2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33376871

RESUMO

Oxidation of thiols yield sulfenic acids, which are very unstable intermediates. As sulfenic acids are reactive, they form disulfides in the presence of thiols. However, sulfenic acids also oxidize to sulfinic acids (-SO2H) and sulfonic acids (-SO3H) at higher concentrations of oxidants. Hydrogen peroxide is a commonly used oxidant for the oxidation of thiols to yield sulfenic acids. However, hydrogen peroxide also oxidizes other reactive functional groups present in a molecule. In this work, the reaction intermediates arising from the oxidation of sterically hindered thiols by aryl chalcogen oxides, dibenzothiophene S-oxide (DBTO), dibenzoselenophene Se-oxide (DBSeO), and dibenzotellurophene Te-oxide (DBTeO), were investigated. Photodeoxygenation of DBTO produces triplet atomic oxygen [O(3P)], which has previously shown to preferentially react with thiols over other functional groups. Similarly, aryl selenoxides have also shown that they can thermally react selectively with thiols at room temperature to yield disulfides. Conversely, aryl telluroxides have been reported to oxidize thiols to disulfides thermally with no selectivity toward thiols. The results from this study demonstrate that sulfenic acids are an intermediate in the oxidation of thiols by DBTeO and by photodeoxygenation of DBTO. The results also showed that the oxidation of thiols by DBSeO yields sulfonic acids. Triptycene-9-thiol and 9-fluorotriptycene-10-thiol were for the thiols used in this oxidation reaction. This work expands the list of oxidants that can be used to oxidize thiols to obtain sulfenic acids.

8.
RSC Adv ; 10(44): 26553-26565, 2020 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-35519784

RESUMO

A beneficial property of photogenerated reactive oxygen species (ROS) is the capability of oxidant generation within a specific location or organelle inside a cell. Dibenzothiophene S-oxide (DBTO), which is known to undergo a photodeoxygenation reaction to generate ground state atomic oxygen [O(3P)] upon irradiation, was functionalized to afford localization within the plasma membrane of cells. The photochemistry, as it relates to oxidant generation, was studied and demonstrated that the functionalized DBTO derivatives generated O(3P). Irradiation of these lipophilic O(3P)-precursors in the presence of LDL and within RAW 264.7 cells afforded several oxidized lipid products (oxLP) in the form of aldehydes. The generation of a 2-hexadecenal (2-HDEA) was markedly increased in irradiations where O(3P) was putatively produced. The substantial generation of 2-HDEA is not known to accompany the production of other ROS. These cellular irradiation experiments demonstrate the potential of inducing oxidation with O(3P) in cells.

9.
Mikrochim Acta ; 187(1): 29, 2019 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-31813061

RESUMO

This review (with 163 refs) covers the recent developments of nanomaterial-based optical and electrochemical sensors for mycotoxins. The review starts with a brief discussion on occurrence, distribution, toxicity of mycotoxins and the legislations in monitoring their levels. It further outlines the research methods, various recognition matrices and the strategies involved in the development of highly sensitive and selective sensor systems. It also points out the salient features and importance of aptasensors in the detection of mycotoxins along with the different immobilization methods of aptamers. The review meticulously discusses the performance of different optical and electrochemical sensors fabricated using aptamers coupled with nanomaterials (CNT, graphene, metal nanoparticles and metal oxide nanoparticles). The review addresses the limitations in the current developments as well as the future challenges involved in the successful construction of aptasensors with the functionalized nanomaterials. Graphical abstract Recent developments in nanomaterial based aptasensors for mycotoxins are summarized. Specifically, the efficiency of the nanomaterial coupled aptasensors (such as CNT, graphene, metal nanoparticles and metal oxide nanoparticles) in optical and electrochemical methods are discussed.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais , Técnicas Eletroquímicas , Micotoxinas/análise , Nanoestruturas/química , Imagem Óptica , Humanos , Tamanho da Partícula , Propriedades de Superfície
10.
Reprod Biomed Online ; 39(4): 685-697, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31515170

RESUMO

RESEARCH QUESTION: A close association between Kisspeptin-1 (KISS-1) and reproductive physiology has been reported, but the results on circulatory KISS-1 are ambiguous in patients with polycystic ovary syndrome (PCOS). A systematic review and meta-analysis were conducted to evaluate the association between KISS-1 and PCOS, and to test its diagnostic test accuracy (DTA) through DTA meta-analysis. DESIGN: Relevant studies were identified by searching PubMed and other databases in addition to manual searching of cross-references. Random-effects model was used to obtain standardized mean differences (SMD), pooled correlation coefficients and summary of DTA. Meta-regression and sub-group analyses were conducted to explore heterogeneity. The presence of publication bias was tested using funnel plot analysis. RESULTS: This meta-analysis finally included 12 studies. Compared with controls, women with PCOS showed significantly increased circulatory KISS-1 levels (SMD = 0.47; P = 0.002). Meta-analysis of correlations showed positive associations between KISS-1 and anti-Müllerian hormone (AMH) (P = 0.03), testosterone (P < 0.001) and dehydroepiandrosterone (P = 0.004). The pooled diagnostic odds ratio and area under curve were 13.71 and 0.835, respectively. A one-study leave-out sensitivity analysis indicated that no single study had a significant influence on the overall outcome, suggesting the robustness of this meta-analysis. CONCLUSIONS: This meta-analysis showed significantly increased KISS-1 level in PCOS, and its association with AMH reflects its role in reproductive physiology. In our DTA meta-analysis, KISS-1 showed good accuracy for PCOS detection. Further large-scale studies are required to establish its validity.


Assuntos
Técnicas de Diagnóstico Endócrino/normas , Testes Diagnósticos de Rotina/normas , Kisspeptinas/sangue , Síndrome do Ovário Policístico/sangue , Hormônio Antimülleriano/sangue , Estudos de Casos e Controles , Testes Diagnósticos de Rotina/métodos , Feminino , Humanos , Síndrome do Ovário Policístico/diagnóstico , Síndrome do Ovário Policístico/epidemiologia , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Testosterona/sangue
11.
Mater Sci Eng C Mater Biol Appl ; 101: 103-110, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31029303

RESUMO

Continuous periodical monitoring of clopidogrel in physiological body fluids is indispensable in medical diagnosis of heart ailments and cardiovascular diseases. A highly sensitive electrochemical sensor has been fabricated with silver nanoparticles embedded chitosan-carbon nanotube hybrid composite (AgChit-CNT) as sensor interface for detection of the important anti-platelet drug, clopidogrel (CLP). Synthesized AgChit-CNT nanocomposite is examined by x-ray diffraction, Raman spectroscopy and field emission scanning electron microscopy for its chemical and structural characteristics. Crystalline silver nanoparticles of about 35 nm are well distributed in the composite and have formed continuous chain like linkages with CNTs all throughout. Electrochemical responses of the fabricated AgChit-CNT nanocomposite electrode for the determination of CLP have been examined by cyclic voltammetry and electrochemical impedance spectroscopy. The nanoAg patterned CNT nanocomposite interface acts as an excellent electron transfer mediator towards the oxidation of clopidogrel. Electrochemical determination of CLP was investigated by differential pulse voltammetry (DPV) and amperometric analysis under optimized conditions. The limit of detection by DPV and amperometry were 30 nM and 10 nM, respectively, and the time of the analysis is as low as 10 s. Practical applicability for determination in artificially prepared urine and pharmaceutical formulation has been examined with good recovery limits of 95.2 to 102.6%.


Assuntos
Técnicas Biossensoriais/métodos , Quitosana/química , Clopidogrel/análise , Técnicas Eletroquímicas/métodos , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Prata/química , Catálise , Clopidogrel/urina , Eletrodos , Nanopartículas Metálicas/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Oxirredução , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , Análise Espectral Raman , Comprimidos
12.
Gynecol Endocrinol ; 35(3): 190-197, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30614305

RESUMO

The association between circulating betatrophin levels and polycystic ovary syndrome (PCOS) is controversial and the studies in the literature are inconsistent. The aim of our study was to systematically review and meta-analyze all available literature comparing circulating betatrophin levels between human PCOS patients and controls. Relevant studies were retrieved by online database and manual searching. A total of 11 studies were included in this meta-analysis. The standardized mean differences (SMDs) with 95% confidence intervals (CIs) were obtained by a random-effects meta-analysis. Meta-analysis of correlations was performed for the associations of betatrophin with anthropometric, lipid and hormonal covariates in PCOS patients. The results indicated that the betatrophin levels were significantly elevated in PCOS patients as compared to non-PCOS controls (SMD = 0.73, 95% CI = 0.22-1.24, Z = 2.83, p = .005). A one-study leave-out sensitivity analysis indicated that no single study had a significant influence on the overall outcome, suggesting the robustness of this meta-analysis. Our sub-group analysis indicated that this increase in betatrophin concentrations was regardless of normo-weight or obese body mass index (BMI) and insulin resistance might have an important role. There were significant positive correlations of betatrophin with age, free androgen index and free-testosterone in PCOS patients. In summary, regardless of BMI, the circulatory betatrophin levels are elevated in PCOS patients compared to controls. PCOS patients with higher insulin resistance had substantially higher circulating betatrophin concentrations.


Assuntos
Proteínas Semelhantes a Angiopoietina/sangue , Índice de Massa Corporal , Resistência à Insulina/fisiologia , Hormônios Peptídicos/sangue , Síndrome do Ovário Policístico/sangue , Proteína 8 Semelhante a Angiopoietina , Biomarcadores/sangue , Feminino , Humanos
13.
J Microsc Ultrastruct ; 6(2): 93-98, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30221133

RESUMO

INTRODUCTION: Mastitis is caused by different Staphylococcus species, produce great economic loss to farmers. Present study was conducted to know pathological changes in mice inoculated with Staphylococcus epidermidis, S. chromogenes, S. haemolyticus and S. aureus isolated from bovine milk. MATERIALS AND METHODS: Mice were inoculated with 50 µl (2x104 cfu organisms) per mammary gland and euthanized at 6, 12, 24, 48, 72 and 96 h. Mammary gland weight, gross and histopathological changes of mammary gland, liver, kidney, spleen, heart, lung and inguinal lymph node were studied. RESULTS: Mammary gland weight and percentage of body weight increased at 6 and 96 h in S. aureus and S. haemolyticus infected mice. Gross changes were observed in mammary gland but not in other organs. Mammary gland revealed gross changes from 24 to 72 h in three Coagulase negative staphylococcal (CNS) species and persisted up to 96 h in S. aureus infected mice. Histopathological changes in mammary glands was severe in S. aureus and moderate in CNS species. S. aureus infected mice revealed severe damage to alveoli and loss of alveolar architecture at 96 h but three CNS species infection was overcome by host factors which was evident by proliferation of alveolar epithelial cells. No histological changes were observed in kidney, spleen, lung, heart and inguinal lymph nodes. CONCLUSIONS: S. aureus caused severe mastitis in mice when compared to CNS species. Further, it is first report of mice to study CNS mastitis, and in future it can be used as model for CNS mastitis.

14.
J Colloid Interface Sci ; 524: 236-244, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29655142

RESUMO

Guiding and capturing photons at the nanoscale by means of metal nanoparticles and interfacial engineering for preventing back-electron transfer are well documented techniques for performance enhancement in excitonic solar cells. Drifting from the conventional route, we propose a simple one-step process to integrate both metal nanoparticles and surface passivation layer in the porous photoanode matrix of a dye-sensitized solar cell. Silver nanoparticles and Nb2O5 surface passivation layer are simultaneously deposited on the surface of a highly porous nanocrystalline TiO2 photoanode, facilitating an absorption enhancement in the 465 nm and 570 nm wavelength region and a reduction in back-electron transfer in the fabricated dye-sensitized solar cells together. The TiO2 photoanodes were prepared by spray pyrolysis deposition method from a colloidal solution of TiO2 nanoparticles. An impressive 43% enhancement in device performance was accomplished in photoanodes having an Ag-incorporated Nb2O5 passivation layer as against a cell without Ag nanoparticles. By introducing this idea, we were able to record two benefits - the metal nanoparticles function as the absorption enhancement agent, and the Nb2O5 layer as surface passivation for TiO2 nanoparticles and as an energy barrier layer for preventing back-electron transfer - in a single step.

15.
Vet Sci ; 5(1)2018 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-29495649

RESUMO

Accurate and early diagnosis of animal rabies is critical for undertaking public health measures. Whereas the direct fluorescent antibody (DFA) technique is the recommended test, the more convenient, direct rapid immunochemistry test (dRIT), as well as the more sensitive, reverse transcription polymerase chain reaction (RT-PCR), have recently been employed for the laboratory diagnosis of rabies. We compared the three methods on brain samples from domestic (dog, cat, cattle, buffalo, horse, pig and goat) and wild (leopard, wolf and jackal) animals from various parts of India. Of the 257 samples tested, 167 were positive by all the three tests; in addition, 35 of the 36 decomposed samples were positive by RT-PCR. This is the first study in which such large number of animal samples have been subjected to the three tests simultaneously. The results confirm 100% corroboration between DFA and dRIT, buttress the applicability of dRIT in the simple and rapid diagnosis of rabies in animals, and reaffirm the suitability of RT-PCR for samples unfit for testing either by DFA or dRIT.

16.
Dalton Trans ; 47(13): 4685-4700, 2018 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-29537003

RESUMO

Engineering photons on a nanoscale via guidance and localization by metal nanostructures has a profound influence on the performance of devices that try to mimic the process of photosynthesis. The conventional route for the synthesis of plasmonic nanoparticles and their integration into the porous structure of the photoanode either directly or after being capped with a dielectric material not only adds to the complexity but also to the cost of the cell. The present study introduces the concept of a plasmonic blocking layer that concurrently acts as a light harvester and an electron-blocking layer in a dye-sensitized solar cell (DSSC), wherein the plasmonic silver nanoparticles are incorporated into an Nb2O5 blocking layer by a simple one-step process. The cell with the plasmonic blocking layer achieves an efficiency of 9.24% when compared with a cell with a non-plasmonic blocking layer (7.6%), registering an impressive enhancement in the efficiency by 22%. Moreover, the cell with the plasmonic blocking layer shows an improvement in the efficiency by 49% when compared with the cell without a blocking layer (6.19%).

17.
ACS Omega ; 3(9): 11691-11702, 2018 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31459265

RESUMO

Sepiolite nanoclay needles have been selectively localized either in the natural rubber (NR) phase or in the carboxylated nitrile rubber (XNBR) phase of the XNBR/NR (50/50) blend prepared by the solution casting method. In a systematic manner, the role of the difference value between the interaction parameter of individual blend components (NR or XNBR)/solvent and the interaction parameter of sepiolite nanoclay/solvent in selectively localizing the sepiolite nanoclay to the NR phase or the XNBR phase of the XNBR/NR (50/50) blend has been explored. A higher percentage of sepiolite nanoclay resides in the dispersed NR phase when the difference value between the interaction parameter of NR/solvent and the interaction parameter of sepiolite nanoclay/solvent is lower than the difference value between the interaction parameter of XNBR/solvent and the interaction parameter of sepiolite nanoclay/solvent. On the other hand, a higher percentage of sepiolite nanoclay resides in the continuous XNBR phase when the difference value between the interaction parameter of XNBR/solvent and the interaction parameter of sepiolite nanoclay/solvent is lower than the difference value between the interaction parameter of NR/solvent and the interaction parameter of sepiolite nanoclay/solvent. It has been shown that by judiciously choosing different solvent combinations to prepare the blend and to disperse nanoclay, it is possible to fine-tune the difference value between the interaction parameter of individual blend components (NR or XNBR)/solvent and the interaction parameter of sepiolite nanoclay/solvent and dictate the selective localization of sepiolite nanoclay to the NR phase or the XNBR phase of XNBR/NR (50/50) blend. This study shows that it is possible to generate a rubber blend with controlled properties by selectively localizing needlelike sepiolite nanoclay in the dispersed phase or the continuous phase of the rubber blend prepared by the solution casting method.

18.
Mater Sci Eng C Mater Biol Appl ; 79: 93-99, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28629098

RESUMO

An efficient electrochemical sensor for selective detection of the neurotransmitter, epinephrine (Epn), has been fabricated with the aid of a functionalized multiwall carbon nanotube-chitosan biopolymer nanocomposite (Chit-fCNT) electrode. Multiwall carbon nanotubes (CNT) were successfully functionalized with the aid of nitric acid and confirmed by the Raman spectral data. Functionalized carbon nanotubes (fCNT) were dispersed in chitosan solution and the resulting bio-nanocomposite was used for the fabrication of sensor surface by drop and cast method. Electrochemical characteristics of the fabricated sensor were understood using cyclic, differential pulse voltammetry (CV, DPV) and electrochemical impedance analysis for the detection of Epn in phosphate buffer (pH7.4). CV and impedance analysis revealed that the Chit-fCNT modified electrode enhances the electrodic reaction of Epn and facilitated the electron transfer more readily compared to that of bare electrode. Applying DPV for the detection of Epn, achieved 30nM as the lowest detection limit in the determination range of 0.05-10µM and the analytical time as low as 10s. Selective determination of Epn against the coexistence of a number of biological electroactive interferents and reproducible results for the determination of Epn were demonstrated. The present biosensor has been found efficient for successful direct determination of Epn from pharmaceutical adrenaline formulations and urine samples.


Assuntos
Nanotubos de Carbono , Técnicas Biossensoriais , Técnicas Eletroquímicas , Eletrodos , Epinefrina , Nanocompostos , Comprimidos
19.
Indian J Pharm Sci ; 78(1): 166-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27168697

RESUMO

A simple, rapid, specific and highly sensitive spectrofluorimetric method has been developed for the quantification of dabigatran etexilate mesylate in bulk and capsule dosage form. A linear relationship was found between fluorescence intensity and concentration in the range of 0.01-1.0 µg/ml in dimethyl sulphoxide as solvent at an emission wavelength of 391 nm after excitation at 334 nm, with a good correlation coefficient (0.989). The detection and quantification limits were found to be 0.005 and 0.015 µg/ml, respectively. The proposed method was applied for dabigatran etexilate mesylate capsules, results reveal with percentage recovery of 102% and percentage relative standard deviation values were found to be less than 2 for accuracy and precision studies. The proposed method was validated for linearity, range, accuracy, precision, limit of detection and quantification according to International Conference on Harmonization guidelines. Statistical analysis of the results revealed high accuracy and good precision. The suggested procedures could be used for the determination of dabigatran etexilate mesylate in bulk and capsule dosage form in quality control laboratories of industries as well as in academic institutions.

20.
J Clin Diagn Res ; 10(3): PD17-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27134936

RESUMO

Trichoepitheliomas (TE) are benign tumours but occasionally can undergo transformation to malignant neoplasms more commonly as Basal Cell Carcinoma (BCC). The correct diagnosis between these tumours is very important because basal cell carcinoma is locally aggressive neoplasm and requires total surgical excision with wide healthy margins while trichoepithelioma needs simple excision. We describe three patients who developed basal cell carcinoma with facial trichoepitheliomas. The only clinical feature that distinguished the carcinomas from the trichoepitheliomas was their larger size, in all three patients, one patient with recurrent, hyper pigmented swelling with surface ulceration and in another patient there are multiple trichoepitheliomas, and other family members are also affected. The history, clinical features and histopathological findings were suggestive of the evolution of basal cell carcinoma directly from trichoepithelioma in our first two cases, but in the third case TE and BCC were separate lesions on face and we are uncertain about whether the BCC developed independently or by transformation from a trichoepithelioma. Based on our clinicopathological observations in the three patients and reports in the recent literature, BCC with follicular differentiation and trichoepithelioma are considered to be highly related.

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