Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Artículo en Inglés | MEDLINE | ID: mdl-38715453

RESUMEN

The identification of novel acetylcholinesterase inhibitors holds significant relevance in the treatment of Alzheimer's disease (AD), the prevailing form of dementia. The exploration of alternative inhibitors to the conventional acetylcholinesterase inhibitors is steadily gaining prominence. Quinones, categorized as plant metabolites, represent a specific class of compounds. In this study, the inhibitory effects of various naphthoquinone derivatives, along with anthraquinone and its derivatives, on the acetylcholinesterase (AChE) enzyme were investigated for this purpose. An in vitro investigation was conducted to examine the effects of these compounds in order to clarify the possible mechanism of inhibition in the interaction between the enzyme and chemicals. In addition, an in silico investigation was carried out to understand the conceivable inhibitor binding process to the enzyme's active site. The acquired outcomes corroborated the in vitro results. The AChE enzyme was found to be effectively inhibited by both naphthoquinones and anthraquinones, with inhibition constant (KI) values ranging from 0.014 to 0.123 µM (micormolar). The AChE enzyme was inhibited differently by this quinone and its derivatives. Although derivatives of naphthoquinone and anthraquinone exhibited a competitive inhibitory effect, derivatives of anthraquinone exhibited a noncompetitive inhibition effect. Furthermore, because it had the lowest KI value of any of these substances, 1,5-dihydroxyanthraquinone (1c) was shown to be the most potent inhibitor. The findings will add to the body of knowledge on the creation of fresh, potent, and successful treatment approaches.

2.
J Trace Elem Med Biol ; 83: 127371, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38176319

RESUMEN

INTRODUCTION: Releasing of cerium oxide nanoparticles (nano-CeO2) to the nature has increased due to the widespread use in many fields ranging from cosmetics to the food industry. Therefore, nano-CeO2 has been included in the Organization for Economic Co-operation and Development's (OECD) priority list for engineering nanomaterials. In this study, the effects of nano-CeO2 on the freshwater mussels were investigated to reveal the impact on the freshwater systems on model organism. METHODS: First, the chemical and structural properties of nano-CeO2 were characterized in details. Second, the freshwater mussels were exposed to environmentally relevant concentrations of nano-CeO2 as 10 mg, 25 mg and 50 mg/L during 48-h and 7-d. Third, after the exposure periods, hemolymph and tissue samples were taken to analyse the Total Hemocyte Counts (THCs) histology and oxidative stress parameters (total antioxidant status, glutathione, glutathione-S-transferase, and advanced oxidative protein products). RESULTS: Significant decrease of the THCs was observed in the nano-CeO2 exposed mussels compared to the control group (P < 0.05). The histological results showed a positive association between nano-CeO2 exposure concentration in the water and level of tissue damage and histopathological alterations were detected in the gill and the digestive gland tissues. Oxidative stress parameters were slightly affected after exposure to nano-CeO2 (P > 0.05). In conclusion, this study showed that acute exposure of freshwater mussels to nano-CeO2 did not pose significant biological risk. However, it has been proven that mussels are able to accumulate nano-CeO2 significantly in their bodies. CONCLUSION: This suggests that nano-CeO2 may be a potential risk to other organisms in the ecosystem through trophic transfer in the food-web based on their habitat and niche in the ecosystem.


Asunto(s)
Bivalvos , Cerio , Nanopartículas , Unio , Animales , Unio/metabolismo , Ecosistema , Nanopartículas/toxicidad , Nanopartículas/química , Cerio/toxicidad , Cerio/química , Estrés Oxidativo , Agua Dulce/química , Glutatión/metabolismo
3.
J Cell Mol Med ; 27(21): 3388-3394, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37772794

RESUMEN

It is known that oxidative stress originating from reactive oxygen species plays a role in the pathogenesis of Alzheimer's disease. In this study, the role of antioxidant status associated with oxidative stress in Alzheimer's disease was investigated. Peripheral blood samples were obtained from 28 healthy individuals (as control) and 28 Alzheimer's patients who met the National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorders Association criteria. Catalase, glutathione S-transferase and paraoxonase 1 enzyme activities in blood plasma and glutathione S-transferase enzyme activities in erythrocytes were determined by spectrophotometer. Catalase, glutathione S-transferase and presenilin 1 gene expressions in leukocytes were determined using qRT-PCR. Data were analysed with SPSS one-way anova, a LSD post hoc test at p < 0.05. The activity of each enzyme was significantly reduced in Alzheimer's patients compared to control. The catalase gene expression level did not change compared to the control. Glutathione S-transferase and presenilin 1 gene expression levels were increased compared to the control.


Asunto(s)
Enfermedad de Alzheimer , Antioxidantes , Humanos , Antioxidantes/metabolismo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Catalasa/genética , Catalasa/metabolismo , Presenilina-1/genética , Presenilina-1/metabolismo , Estrés Oxidativo/genética , Glutatión Transferasa/genética , Expresión Génica
4.
Sci Total Environ ; 903: 166042, 2023 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-37543338

RESUMEN

In the last few decades, industrial pollution has gained extensive attention in terms of its effect on the aquatic environment. This imposes the need to develop sensitive biomarkers for early detection of pollutant toxicity in ecotoxicological assessment. The advantages of histopathological biomarkers are many, including quick reaction to the presence of contaminants, and the small number of individuals needed for efficient analysis. The present study analyzed the negative effect of lignite coal fly ash (LCFA) and microplastic particles (MPs) on Chironomus riparius, a suggested model organism by the Organization for Economic Cooperation and Development (OECD). This study aimed to perform histological analyses of larval tissues and target potential changes in treated groups that could serve as promising histopathological biomarkers of the contaminant's negative effects. Following that, other known sensitive sub-organismal biomarkers were analyzed and paired with the histopathological ones. Histological analysis of larvae showed a significantly decreased length of microvilli in midgut regions II and III in both treatments. Treatments with MPs affected oxidative stress parameters: thiobarbituric acid reactive substances (TBARS), advanced oxidation protein products (AOPP), superoxide dismutase (SOD), and hemoglobin levels, while LCFA significantly affected all tested sub-organismal biomarkers (DNA damage, levels of AOPP, SOD, and hemoglobin), except catalase (CAT) and TBARS. When observing histological slides, a significant shortage of brush border length in the posterior parts of the midgut was detected in all treatments. In the case of LCFA, the appearance of intensive vacuolization of digestive cells with inclusions resembling apoptotic bodies, in mentioned regions was also detected. This study demonstrated high sensitivity of brush border length to the MPs and LCFA exposure, complementary to other tested sub-organismal biomarkers. Revealing the great potential of this histopathological biomarker in ecotoxicological studies contributes to the international standard ecotoxicology assessment of emerging pollutants.

5.
Chem Biodivers ; 20(8): e202300611, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37470688

RESUMEN

Sulfonamide compounds known as human carbonic anhydrase (hCA) inhibitors are used in the treatment of many diseases such as epilepsy, antibacterial, glaucoma, various diseases. 1,3-diaryl-substituted triazenes and sulfaguanidine are used for therapeutic purposes in many drug structures. Based on these two groups, the synthesis of new compounds is important. In the present study, the novel 1,3-diaryltriazene-substituted sulfaguanidine derivatives (SG1-13) were synthesized and fully characterized by spectroscopic and analytic methods. Inhibitory effect of these compounds on the hCA I and hCA II was screened as in vitro. All the series of synthesized compounds have been identified as potential hCA isoenzymes inhibitory with KI values in the range of 6.44±0.74-86.85±7.01 nM for hCA I and with KI values in the range of 8.16±0.40-77.29±9.56 nM for hCA II. Moreover, the new series of compounds showed a more effective inhibition effect than the acetazolamide used as a reference. The possible binding positions of the compounds with a binding affinity to the hCA I and hCA II was demonstrated by in silico studies. In conclusion, compounds with varying degrees of affinity for hCA isoenzymes have been designed and as selective hCA inhibitors. These compounds may be potential alternative agents that can be used to treat or prevent diseases associated with glaucoma and hCA inhibition.


Asunto(s)
Anhidrasas Carbónicas , Glaucoma , Humanos , Inhibidores de Anhidrasa Carbónica/farmacología , Inhibidores de Anhidrasa Carbónica/química , Anhidrasas Carbónicas/metabolismo , Simulación del Acoplamiento Molecular , Relación Estructura-Actividad , Sulfaguanidina , Isoenzimas/metabolismo , Anhidrasa Carbónica I/metabolismo , Glaucoma/tratamiento farmacológico , Estructura Molecular
6.
Biotechnol Appl Biochem ; 70(1): 68-82, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35112394

RESUMEN

Alzheimer's disease (AD) is a neurodegenerative disorder. The disease is characterized by dementia, memory impairment, cognitive impairment, and speech impairment. Cholinesterases (ChEs; AChE, acetylcholinesterase and BChE, butyrylcholinesterase) inhibitors and their benefits of cholinergic replacement in the treatment of AD have been researched and documented by scientists in various ways to date. Recent studies prove that human carbonic anhydrases (hCAs) are also one of the important targets in the treatment of AD. Therefore, the development of new agents that can simultaneously modulate the various mechanisms or targets involved in the AD pathway may be a powerful strategy to treat AD, the current disease. Considering these data, the effects of the pyrimidines (1-7) were investigated in this study for the discovery and development of multitargeted ChEs and hCAs inhibitors associated with AD. In addition, the molecular docking analysis of the 4-amino-2-choloropyrimidine (2) was performed to understand the binding interactions on the active site of the enzyme. All compounds (1-7) showed satisfactory enzyme inhibitory potency in micromolar concentrations against AChE, BChE, hCAI, and hCAII with KI values ranging from 0.099 to 0.241 µM, from 1.324 to 3.418 µM, from 0.201 to 0.884 µM, from 1.867 to 3.913 µM, respectively. Due to their ChEs and hCAs inhibition, these compounds (1-7) may be considered as leads for investigations in neurodegenerative diseases. All these results revealed that the 4-amino-5,6-dichloropyrimidine (7) (KI value of 0.201 ± 0.041 µM for hCA I), the 4-amino-6-hydroxypyrimidine (4) (KI value of 1.867 ± 0.296 µM for hCA II), the 4-amino-5,6-dichloropyrimidine (7) (KI value of 0.099 ± 0.008 µM for AChE), and the 4-amino-2-chloropyrimidine (2) (KI value of 1.324 ± 0.273 µM for BChE) from the pyrimidines in this series were the most promising derivatives, as they exhibited a good multifunctional inhibition at all experimental levels and in the in silico validation against these enzymes, for the treatment of AD.


Asunto(s)
Butirilcolinesterasa , Anhidrasas Carbónicas , Humanos , Butirilcolinesterasa/química , Butirilcolinesterasa/metabolismo , Acetilcolinesterasa/química , Simulación del Acoplamiento Molecular , Anhidrasas Carbónicas/metabolismo , Inhibidores de la Colinesterasa/farmacología , Inhibidores de la Colinesterasa/química , Pirimidinas/farmacología , Estructura Molecular , Relación Estructura-Actividad
7.
Biotechnol Appl Biochem ; 70(1): 415-428, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35638720

RESUMEN

Human carbonic anhydrase VII (hCA VII), a cytosolic enzyme, defends against oxidative stress by preventing reactive oxygen species from forming. In our study, first, hCA VII was cloned into Escherichia coli (One Shot Mach1-T1R) strain by using cDNA of the human brain and successfully expressed. The integrity of the plasmid generated by colony PCR was checked, and after, for protein expression, the plasmid was transformed into E. coli BL21 (DE-3) strain. hCA VII expression was observed after 6 h of isopropyl-D-1-thiogalactopyranoside (IPTG) induction. The fusion protein containing hexahistidine (6xHis) was purified with 7.02 EU/mg of specific activity, had 48.07% of purification yield, and approximately 21-folds using a ProbondTM nickel chelating resin affinity column. Then, both molecular mass determination and purity control of the purified recombinant enzyme was done by SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis). The mass of the SUMO-hCA VII fusion protein was calculated as 46.77 kDa. As a result of Western blot analysis using anti-His G-HRP antibody, the fusion protein was detected as approximately 45 kDa. Furthermore, the characterization assays and in vitro inhibition studies were done for the recombinant enzyme. KI values of these agents were found between 0.29 µM and 157.6 mM. Finally, molecular docking investigations of these antibiotics were undertaken to understand further the binding interactions on the active site of this recombinant enzyme.


Asunto(s)
Anhidrasas Carbónicas , Escherichia coli , Humanos , Escherichia coli/genética , Escherichia coli/metabolismo , Simulación del Acoplamiento Molecular , Anhidrasas Carbónicas/genética , Anhidrasas Carbónicas/metabolismo , Plásmidos
8.
Mol Divers ; 27(4): 1735-1749, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36136229

RESUMEN

To discover alternative substances to compounds used to treat many diseases, especially treating Alzheimer's disease (AD) and Parkinson's disease targeting carbonic anhydrase (hCA) and acetylcholinesterase (AChE) enzymes, is important. For this purpose, a series of novel bis-ureido-substituted sulfaguanidine (SG1-4) and sulfisoxazole (SO1-4) derivatives were synthesized, and their inhibitory capacities were screened against hCA isoenzymes (hCA I and II) and AChE. Possible binding mechanisms of inhibitors to the active site were elucidated by in silico studies, and the results were supported by in vitro results. Moreover, the percent radical scavenging capacities of the derivatives were also evaluated. The derivatives (SG1-4 and SO1-4) were more effective against hCAs compared to standard drug acetazolamide (KI values of 98.28-439.17 nM for hCA I and II, respectively) and exhibited the highest inhibition with the KIs in the ranges of 2.54 ± 0.50-41.02 ± 7.52 nM for hCA I, 11.20 ± 2.97-67.14 ± 13.58 nM for hCA II, and 257.60 ± 27.84-442.60 ± 52.13 nM for AChE. Also, compounds SG1 and SO1 also showed ABTS radical scavenging activity at the rate of 70% and 78%, respectively. These results will contribute to the literature for the rational design and synthesis of new potent and selective inhibitors targeting hCAs and AChE with multifunctional effects such as radical scavenging as well as inhibition. This study focused on the synthesis and inhibitory effects of bis-ureido-substituted sulfaguanidine (SG1-4) and sulfisoxazole (SO1-4) derivatives against human hCA I and II isoforms and AChE. In order to test synthesized derivatives' free radical scavenging potentials were the DPPH and ABTS assays. In silico studies elucidated possible binding mechanisms of inhibitors to the active site.


Asunto(s)
Anhidrasas Carbónicas , Humanos , Anhidrasas Carbónicas/metabolismo , Inhibidores de la Colinesterasa/química , Acetilcolinesterasa/metabolismo , Sulfisoxazol , Sulfaguanidina , Anhidrasa Carbónica I/metabolismo , Anhidrasa Carbónica II/metabolismo , Inhibidores de Anhidrasa Carbónica/farmacología , Inhibidores de Anhidrasa Carbónica/química , Relación Estructura-Actividad , Estructura Molecular
9.
ACS Omega ; 7(28): 24669-24678, 2022 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-35874251

RESUMEN

Hybrids of nitrate-based molten salts (KNO3, NaNO3, and Solar Salt) and anodic aluminum oxide (AAO) with various pore sizes (between 25 and 380 nm) were designed for concentrated solar power (CSP) plants to achieve low melting point (<200 °C) and high thermal conductivity (>1 W m-1 K-1). AAO pore surfaces were passivated with octadecyl phosphonic acid (ODPA), and the results were compared with as-anodized AAO. The change in phase transition temperatures and melting temperatures of salts was investigated as a function of pore diameter. Melting temperatures decreased for all salts inside AAO with different pore sizes while the highest melting temperature decrease (ΔT = 173 ± 2 °C) was observed for KNO3 filled in AAO with a pore diameter of 380 nm. Another nanoconfinement effect was observed in the crystal phases of the salts. The ferroelectric phase of KNO3 (γ-phase) formed at room temperature for KNO3/AAO hybrids with pore size larger than 35 nm. Thermal conductivity values of molten salt (MS)/AAO hybrids were obtained by thermal property analysis (TPS) at room temperature and above melting temperatures of the salts. The highest increase in thermal conductivity was observed as 73% for KNO3/AAO-35 nm. For NaNO3/AAO-380 nm hybrids, the thermal conductivity coefficient was 1.224 ± 0.019 at room temperature. To determine the capacity and efficiency of MS/AAO hybrids during the heat transfer process, the energy storage density per unit volume (J m-3) was calculated. The highest energy storage capacity was calculated as 2390 MJ m-3 for KNO3/AAO with a pore diameter of 400 nm. This value is approximately five times higher than that of bulk salt.

10.
Bioorg Chem ; 117: 105473, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34768205

RESUMEN

Aldose reductase (ALR2), one of the metabolically important enzymes, catalyzes the formation of sorbitol from glucose in the polyol pathway. ALR2 inhibition is required to prevent diabetic complications. In the present study, the novel bis-hydrazone compounds bearing isovanillin moiety (GY1-12) were synthesized, and various chromatographic methods were applied to purify the ALR2 enzyme. Afterward, the inhibitory effect of the synthesized compounds on the ALR2 was screened in vitro. All the novel bis-hydrazones demonstrated activity in nanomolar levels as AR inhibitors with IC50 and KI values in the range of 12.55-35.04 nM, and 13.38-88.21 nM, respectively. Compounds GY-11, GY-7, and GY-5 against ALR2 were identified as the highly potent inhibitors, respectively, and were superior to the standard drug, epalrestat. Moreover, a comprehensive ligand-receptor interactions prediction was performed using ADME-Tox, Glide XP, and MM-GBSA modules of Schrödinger Small-Molecule Drug Discovery Suite to elucidate the novel bis-hydrazone derivatives, potential binding modes versus the ALR2. As a result, these compounds with ALR2 inhibitory effects may be potential alternative agents that can be used to treat or prevent diabetic complications.


Asunto(s)
Aldehído Reductasa/antagonistas & inhibidores , Benzaldehídos/farmacología , Inhibidores Enzimáticos/farmacología , Hidrazonas/farmacología , Aldehído Reductasa/metabolismo , Benzaldehídos/química , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Humanos , Hidrazonas/síntesis química , Hidrazonas/química , Simulación del Acoplamiento Molecular , Estructura Molecular , Relación Estructura-Actividad
11.
Arch Pharm (Weinheim) ; 353(12): e2000118, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32761859

RESUMEN

Aldose reductase (AR) is the first and rate-limiting enzyme of the polyol pathway, which converts glucose to sorbitol in an NADPH-dependent reaction. α-Glycosidase breaks down starch and disaccharides to glucose. Hence, inhibition of these enzymes can be regarded a considerable approach in the treatment of diabetic complications. AR was purified from sheep liver using simple chromatographic methods. The inhibitory effects of pyrazolyl-thiazoles ((3aR,4S,7R,7aS)-2-(4-{1-[4-(4-bromophenyl)thiazol-2-yl]-5-(aryl)-4,5-dihydro-1H-pyrazol-3-yl}phenyl)-3a,4,7,7a-tetrahydro-1H-4,7-methanoisoindole-1,3(2H)-dione derivatives; 3a-i) on AR and α-glycosidase enzymes were investigated. All compounds showed a good inhibitory action against AR and α-glycosidase. Among these compounds, compound 3d exhibited the best inhibition profiles against AR, with a Ki value of 7.09 ± 0.19 µM, whereas compound 3e showed the lowest inhibition effects, with a Ki value of 21.89 ± 1.87 µM. Also, all compounds showed efficient inhibition profiles against α-glycosidase, with Ki values in the range of 0.43 ± 0.06 to 2.30 ± 0.48 µM, whereas the Ki value of acarbose was 12.60 ± 0.78 µM. Lastly, molecular modeling approaches were implemented to predict the binding affinities of compounds against AR and α-glycosidase. In addition, the ADME analysis of the molecules was performed.


Asunto(s)
Aldehído Reductasa/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Glicósido Hidrolasas/antagonistas & inhibidores , Hipoglucemiantes/farmacología , Simulación del Acoplamiento Molecular , Pirazoles/farmacología , Tiazoles/farmacología , Aldehído Reductasa/metabolismo , Animales , Sitios de Unión , Diseño de Fármacos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/metabolismo , Glicósido Hidrolasas/metabolismo , Hipoglucemiantes/síntesis química , Hipoglucemiantes/metabolismo , Hígado/enzimología , Unión Proteica , Pirazoles/síntesis química , Pirazoles/metabolismo , Oveja Doméstica , Tiazoles/síntesis química , Tiazoles/metabolismo
12.
ACS Omega ; 5(26): 15850-15864, 2020 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-32656406

RESUMEN

Development of innovative methodologies to convert biomass ash into useful materials is essential to sustain the growing use of biomass for energy production. Herein, a simple chemical modification approach is employed to functionalize biomass fly ash (BFA) with 3-aminopropyltriethoxy silane (APTES) to develop an inexpensive and efficient adsorbent for water remediation. The amine-functionalized BFA (BFA-APTES) was fully characterized by employing a range of characterization techniques. Adsorption behavior of BFA-APTES was evaluated against two anionic dyes, namely, alizarin red S (ARS) and bromothymol blue (BTB). In the course of experimental data analysis, the computation tools of data fitting for linear and nonlinear form of Langmuir, Freundlich, and the modified Langmuir-Freundlich adsorption isotherms were used with the aid of Matlab R2019b. In order to highlight the misuse of linearization of adsorption models, the sum of the squares of residues (SSE) values obtained from nonlinear models are compared with R 2 values obtained from the linear regression. The accuracy of the data fitting was checked by the use of SSE as an error function instead of the coefficient of determination, R 2. The dye adsorption capacity of BFA-APTES was also compared with the nonfunctionalized BFA. The maximum adsorption capacities of BFA-APTES for ARS and BTB dye molecules were calculated to be around 13.42 and 15.44 mg/g, respectively. This value is approximately 2-3 times higher than the pristine BFA. A reasonable agreement between the calculated and experimental values of q e obtained from the nonlinear form of kinetic models verified the importance of using equations in their original form. The experimentally calculated thermodynamic parameters including molar standard Gibbs free energy (Δad G m 0) and molar standard enthalpy change (Δad H m 0) reflected that the process of adsorption of dye molecules on the BFA-APTES adsorbent was spontaneous and exothermic in nature. Moreover, the used BFA-APTES adsorbent could be regenerated and reused for several cycles with significant dye adsorption capacity. The remediation capability of the BFA-APTES adsorbent against ARS dye was also demonstrated by packing a small column filled with the BFA-APTES adsorbent and passing a solution of ARS through it. Overall, we provide a simple and scalable route to convert BFA into an efficient adsorbent for water remediation applications.

13.
Anal Bioanal Chem ; 412(14): 3299-3315, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32107572

RESUMEN

Spectroscopy with planar optical waveguides is still an active field of research for the quantitative analysis of various supramolecular surface architectures and processes, and for applications in integrated optical chip communication, direct chemical sensing, etc. In this contribution, we summarize some recent development in optical waveguide spectroscopy using nanoporous thin films as the planar substrates that can guide the light just as well as bulk thin films. This is because the nanoporosity is at a spacial length-scale that is far below the wavelength of the guided light; hence, it does not lead to an enhanced scattering or additional losses of the optical guided modes. The pores have mainly two effects: they generate an enormous inner surface (up to a factor of 100 higher than the mere geometric dimensions of the planar substrate) and they allow for the exchange of material and charges between the two sides of the solid thin film. We demonstrate this for several different scenarios including anodized aluminum oxide layers for the ultrasensitive determination of the refractive index of fluids, or the label-free detection of small analytes binding from the pore inner volume to receptors immobilized on the pore surface. Using a thin film of Ti metal for the anodization results in a nanotube array offering an even further enhanced inner surface and the possibility to apply electrical potentials via the resulting TiO2 semiconducting waveguide structure. Nanoporous substrates fabricated from SiNx thin films by colloid lithography, or made from SiO2 by e-beam lithography, will be presented as examples where the porosity is used to allow for the passage of ions in the case of tethered lipid bilayer membranes fused on top of the light-guiding layer, or the transport of protons through membranes used in fuel cell applications. The final example that we present concerns the replication of the nanopore structure by polymers in a process that leads to a nanorod array that is equally well suited to guide the light as the mold; however, it opens a totally new field for integrated optics formats for direct chemical and biomedical sensing with an extension to even molecularly imprinted structures. Graphical abstract.

14.
Appl Biochem Biotechnol ; 190(2): 437-447, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31378842

RESUMEN

Pain, as a sensible alarm signal of living organisms to avoid tissue damage, is a common and debilitating consequence of a lot of disorders and diseases. The management of chronic pain is particularly challenging. For pain treatment, many analgesic drugs are used for their therapeutic effects. In this study, some nonsteroidal anti-inflammatory drugs including etofenamate, meloxicam, diclofenac, and tenoxicam were tested against α-glycosidase from Saccharomyces cerevisiae, sorbitol dehydrogenase (SDH), and aldose reductase (AR) enzymes from sheep liver. Nonsteroidal anti-inflammatory drugs demonstrated useful inhibition properties against α-glycosidase, AR, and SDH enzymes. Ki values were found in the range of 11.93 ± 3.77-364.88 ± 40.01 µM for α-glycosidase, 3.36 ± 1.08µM-17.68 ± 3.39 mM for AR, and 1.68 ± 0.02 µM-30.98 ± 14.31 mM for SDH. They can be selective drugs as antidiabetic agents, because of their inhibitory properties against SDH, α-glycosidase, and AR enzymes.


Asunto(s)
Aldehído Reductasa/antagonistas & inhibidores , Antiinflamatorios no Esteroideos/farmacología , Glicósido Hidrolasas/antagonistas & inhibidores , L-Iditol 2-Deshidrogenasa/antagonistas & inhibidores , Aldehído Reductasa/aislamiento & purificación , Animales , Diabetes Mellitus Experimental/enzimología , Electroforesis en Gel de Poliacrilamida , L-Iditol 2-Deshidrogenasa/aislamiento & purificación , Hígado/enzimología , Ovinos
15.
Environ Toxicol Chem ; 39(1): 131-140, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31581319

RESUMEN

Cerium oxide nanoparticles (CeO2 NPs) are included in the Organisation for Economic Co-operation and Development (OECD) priority list of engineered nanomaterials for assessment of their environmental impact. The present study was carried out to assess the CeO2 NP toxicity to the freshwater midge Chironomus riparius larvae at concentrations of 2.5, 25, 250, and 2500 mg of CeO2 NP/kg of sediment. Experiments were designed to assess the prolonged exposure of midges to CeO2 NPs while adhering to OECD test guideline 218. The following parameters were investigated: CeO2 NP uptake by larvae, oxidative stress parameters, in vivo genotoxic effects, and life trait parameters. Inductively coupled plasma-mass spectrometry analysis showed a significant positive correlation between the concentration of CeO2 NPs in the sediment and its uptake by the larvae. No significant mortality was observed in C. riparius, and oxidative stress was not detected. The only significantly induced sublethal effect was genotoxicity, which began to manifest at a lowest-observed-effect concentration of 25 mg kg-1 of sediment and progressively increased at higher concentrations. Our results indicate that exposure to CeO2 NP-contaminated freshwater sediments does not pose a risk to chironomids at environmentally realistic concentrations. However, the significant accumulation of CeO2 NPs by chironomid larvae may pose a risk through trophic transfer to organisms further up the food chain. Environ Toxicol Chem 2019;39:131-140. © 2019 SETAC.


Asunto(s)
Cerio/toxicidad , Chironomidae/efectos de los fármacos , Daño del ADN , Larva/efectos de los fármacos , Nanopartículas/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Chironomidae/genética , Chironomidae/metabolismo , Cadena Alimentaria , Agua Dulce/química , Estrés Oxidativo/efectos de los fármacos
16.
Psychol Health Med ; 25(2): 171-178, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31635480

RESUMEN

Acne is a common skin disease which can have a negative psychosocial impact on quality of life. Sexual health is an important part of overall health and little is known about the effects of acne on individual sexuality. We aimed to assess the sexual quality of life and general quality of life in female patients with acne and compare to those without acne. Sixty female participants with acne and age-matched 40 female controls were enrolled in the study and asked to complete the Sexual Quality of Life-Female Questionnaire and the Short Form-36 Health Survey. Acne severity was evaluated objectively by the Global Acne Grading System and subjectively by the Visual Analogue Scale. Participants reported a significantly worse sexual quality of life and had significantly decreased scores on the quality of life scales of Bodily Pain, General Perception of Health and the Physical Component Summary when compared to controls. Neither the sexual quality of life nor the quality of life was correlated with objective and subjective acne severity and duration of acne. Acne can negatively affect sexual quality of life in female patients as well as differentdimensions of quality of life. The sexual quality of life should be considered while evaluating acne in women irrespective of its severity.


Asunto(s)
Acné Vulgar/psicología , Calidad de Vida/psicología , Conducta Sexual/psicología , Adolescente , Adulto , Femenino , Humanos , Adulto Joven
17.
Environ Toxicol Pharmacol ; 70: 103195, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31125830

RESUMEN

Diabetes mellitus is a chronic metabolic disease characterized by abnormal glucose metabolism. Aldose reductase (AR) is the first enzyme in the polyol pathway and converts glucose to sorbitol. It plays a vital role as a glucose reducing agent and is involved in the pathophysiology of diabetic complications. In this study, we purified AR from sheep kidney with a specific activity of 2.00 EU/mg protein and 133.33- fold purification After the purification of the AR enzyme, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed and the molecular weight of the enzyme was found approximately as 38 kDa. The inhibition effects of eight quinones were studied against AR. The quinones were potent inhibitors of AR with Ki values in the range of 0.07-20.04 µM. Anthraquinone showed the best potential inhibitory effects against AR. All compounds exhibited noncompetitive inhibition against AR. These compounds may be selective inhibitors of this enzyme. AR inhibition is an essential strategy for the attenuation and prevention of diabetic complications.


Asunto(s)
Aldehído Reductasa/antagonistas & inhibidores , Hipoglucemiantes/química , Quinonas/química , Aldehído Reductasa/química , Aldehído Reductasa/aislamiento & purificación , Animales , Riñón/enzimología , Ovinos
18.
RSC Adv ; 9(63): 36586-36599, 2019 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-35539072

RESUMEN

Non-precious metal-based electrocatalysts on carbon materials with high durability and low cost have been developed to ameliorate the oxygen-reduction reaction (ORR) and oxygen-evolution reaction (OER) for electrochemical energy applications such as in fuel cells and water electrolysis. Herein, two different morphologies of FeNi/NiFe2O4 supported over hierarchical N-doped carbons were achieved via carbonization of the polymer nanofibers by controlling the ratio of metal salts to melamine: a mixture of carbon nanotubes (CNTs) and graphene nanotubes (GNTs) supported over carbon nanofibers (CNFs) with spherical FeNi encapsulated at the tips (G/CNT@NCNF, 1 : 3), and graphene sheets wrapped CNFs with embedded needle-like FeNi (GS@NCNF, 2 : 3). G/CNT@NCNF shows excellent ORR activity (on-set potential: 0.948 V vs. RHE) and methanol tolerance, whilst GS@NCNF exhibited significantly lower over-potential of only 230 mV at 10 mA cm-2 for OER. Such high activities are due to the synergistic effects of bimetallic NPs encapsulated at CNT tips and N-doped carbons with unique hierarchical structures and the desired defects.

19.
RSC Adv ; 9(65): 37846-37857, 2019 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-35541799

RESUMEN

The eutectic mixture of liquid crystals E7 is studied in confinement by means of thermal and dielectric measurements. The uniform 1-D confinement provided by self-ordered nanoporous alumina leads to a decrease in the nematic to isotropic transition temperature due to interaction with the pore surface, e.g. surface anchoring. The prevalence of certain dynamic modes of relaxation is found to depend on the surface properties of the confining pores. The dynamics (i.e., relaxation times) were found to accelerate with increasing confinement, resulting in a decreasing glass temperature, independent of surface treatment. From the pre- and meta-transitional dependence of the dielectric permittivity on temperature we are able to deduce a weakening effect of confinement on the nematic to isotropic (N/I) transition which allows the determination of a critical pore diameter (in the range from 11 nm to 23 nm) below which the transition becomes continuous. Comparison of the N/I transition of E7 to those of its constituent liquid crystals reveals a significantly weaker transition occurring over a widened temperature range. This suggest the importance of concentration fluctuations in rounding first order phase transitions that are triggered by the different length scales and ranges of nematic stability in E7. The results have an impact beyond the present case and for several soft materials (e.g. oligomers used as OLEDs, polymers, colloids) as it demonstrates the importance of concentration fluctuations in addition to thermal fluctuation on the strength of phase transitions.

20.
Acta Dermatovenerol Croat ; 26(3): 220-225, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30390723

RESUMEN

The severity of acne may not directly reflect the psychological state of a patient. The aim of the present study was to evaluate the social appearance anxiety with overall morbidity in patients with acne. One hundred adult patients with acne and 67 age and sex-matched healthy controls were enrolled in the study. The patients and controls were asked to complete the Social Appearance Anxiety Scale (SAAS) and the General Health Questionnaire-12 (GHQ-12). Acne severity was evaluated objectively by the Global Acne Grading System (GAGS) and subjectively by the Visual Analogue Scale (VAS). The mean score on SAAS (37.69±13.53; mean ± Standard deviation) was significantly higher than in the control group (32.48±9.34) (p=0.05). No significant difference was observed between the GHQ-12 scores of the acne (2.19±2.64) and the control group (1.63±2.2) (p=0.152). There was no correlation between the GAGS and the VAS (p=0.417). The SAAS scores of the patients with acne were correlated with the GAGS scores (p=0.05) but not correlated with VAS (p=0.481). The GHQ-12 scores were not correlated with GAGS (p=0.96) or with VAS (p=507). No statistical correlation was established between sex and the GAGS scores (p=0.385), SAAS scores (p=0.611), and GHQ-12 scores (p=0.196). The duration of acne was not correlated with SAAS scores (p=0.814) or with GHQ-12 scores (p=0.24). Social appearance anxiety is significant in adult patients with acne and it is correlated with objective acne severity. However, acne does not seem to be associated with substantial psychological distress or formal psychiatric disorder in adults.


Asunto(s)
Acné Vulgar/psicología , Ansiedad/etiología , Conducta Social , Adulto , Estudios de Casos y Controles , Estudios Transversales , Femenino , Humanos , Masculino , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...