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1.
Sci Rep ; 14(1): 11252, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38755227

RESUMEN

This study employs ab initio calculations based on density functional theory (DFT) to investigate the structural properties, 1H-NMR spectra, and vibrational spectra of methane sulfonic acid (MSA) at low degree of hydration. The findings reveal that energetically stable structures are formed by small clusters consisting of one or two MSA molecules (m = 1 and 2) and one or two water molecules in (MSA)m·(H2O)n (m = 1-2 and n = 1-5).These stable structures arise from the formation of strong cyclic hydrogen bonds between the proton of the hydroxyl (OH) group in MSA and the water molecules. However, clusters containing three or more water molecules (n > 2) exhibit proton transfer from MSA to water, resulting in the formation of ion-pairs composed of CH3SO3- and H3O+species. The measured 1H-NMR spectra demonstrate the presence of hydrogen-bonded interactions between MSA and water, with a single MSA molecule interacting with water molecules. This interaction model accurately represents the hydrogen bonding network, as supported by the agreement between the experimental and calculated NMR chemical shift results.

2.
Nanomaterials (Basel) ; 14(6)2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38535674

RESUMEN

This study introduces a novel nanocomposite coating composed of PANI/CeO2 nanocomposite films, aimed at addressing corrosion protection needs. Analysis through FTIR spectra and XRD patterns confirms the successful formation of the nanocomposite films. Notably, the PANI/CeO2 nanocomposite films exhibit a hydrophilic nature. The bandgap energy of the PANI composite film is measured to be 3.74 eV, while the introduction of CeO2 NPs into the PANI matrix reduces the bandgap energy to 3.67 eV. Furthermore, the electrical conductivity of the PANI composite film is observed to be 0.40 S·cm-1, with the incorporation of CeO2 NPs leading to an increase in electrical conductivity to 1.07 S·cm-1. To evaluate its efficacy, electrochemical measurements were conducted to assess the corrosion protection performance. Results indicate a high protection efficiency of 92.25% for the PANI/CeO2 nanocomposite film.

3.
J Ocul Pharmacol Ther ; 40(1): 78-88, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38252789

RESUMEN

Introduction: The hydrogen-bonded networks play a significant role in influencing several physicochemical properties of ofloxacin in artificial tears (ATs), including density, pH, viscosity, and self-diffusion coefficients. The activities of the ofloxacin antibiotic with Ats mixtures are not solely determined by their concentration but are also influenced by the strength of the hydrogen bonding network which highlight the importance of considering factors such as excessive tear production and dry eye conditions when formulating appropriate dosages of ofloxacin antibiotics for eye drops. Objectives: Investigating the physicochemical properties of ofloxacin-ATs mixtures, which serve as a model for understanding the impact of hydrogen bonding on the antimicrobial activity of ofloxacin antibiotic eye drops. Determine the antimicrobial activities of the ofloxacin-Ats mixture with different concentration of ofloxacin. Methods: The ofloxacin-ATs mixtures were analyzed using 1H-NMR, Raman, and UV-Vis spectroscopies, with variation of ofloxacin concentration to study its dissociation kinetics in ATs, mimicking its behavior in human eye tears. The investigation includes comprehensive analysis of 1H-NMR spectral data, self-diffusion coefficients, Raman spectroscopy, UV-Vis spectroscopy, liquid viscosity, and acidity, providing a comprehensive assessment of the physicochemical properties. Results: Analysis of NMR chemical shifts, linewidths, and self-diffusion coefficient curves reveals distinct patterns, with peaks or minima observed around 0.6 ofloxacin mole fraction dissociated in ATs, indicating a strong correlation with the hydrogen bonding network. Additionally, the pH data exhibits a similar trend to viscosity, suggesting an influence of the hydrogen bonding network on protonic ion concentrations. Antibacterial activity of the ofloxacin-ATs mixtures is evaluated through growth rate analysis against Salmonella typhimurium, considering varying concentrations with mole fractions of 0.1, 0.4, 0.6, 0.8, and 0.9. Conclusions: The antibiotic-ATs mixture with a mole fraction of 0.6 ofloxacin exhibited lower activity compared to mixtures with mole fractions of 0.1 and 0.4, despite its lower concentration. The activities of the mixtures are not solely dependent on concentration but are also influenced by the strength of the hydrogen bonding network. These findings emphasize the importance of considering tear over-secretion and dry eye problems when designing appropriate doses of ofloxacin antibiotics for eye drop formulations.


Asunto(s)
Antibacterianos , Síndromes de Ojo Seco , Humanos , Antibacterianos/farmacología , Ofloxacino/farmacología , Ofloxacino/análisis , Gotas Lubricantes para Ojos , Espectroscopía de Protones por Resonancia Magnética , Lágrimas/química
4.
Sci Rep ; 13(1): 22405, 2023 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-38104224

RESUMEN

The coupling behavior of the wide field surface plasmon microscopy (WF-SPRM) with single-, two-, and multiple-gold nanoparticles (AuNPs) with different AuNPs sizes is investigated using theoretical, simulation, and experimental approaches. The signal intensity of a single AuNP increases from 208 a.u. to 583 a.u. as particle size increases from 40 to 80 nm, which evidences the signal-building mechanism of Rayleigh scattering theory. A discrete particle model of SPR is used to understand the interaction between an Au-layer and a single AuNP. The calculated intensity profile of the single AuNP from the discrete particle model is accepted with the experimental data. In addition, the superposition between 2-AuNPs surface plasmon waves is studied using the finite element method as well as experimental data from WF-SPRM. The surface plasmon waves around the two particles generate an interference pattern. Finally, it is demonstrated that plasmonic multiple particles scattering can be represented by an effective media, which is described by Maxwell-Garnet equations.

5.
Sci Rep ; 13(1): 21092, 2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-38036555

RESUMEN

This study introduces a low-field NMR spectrometer (LF-NMR) featuring a multilayer Halbach magnet supported by a combined mechanical and electrical shimming system. This setup offers improved field homogeneity and sensitivity compared to spectrometers relying on typical Halbach and dipole magnets. The multilayer Halbach magnet was designed and assembled using three nested cylindrical magnets, with an additional inner Halbach layer that can be rotated for mechanical shimming. The coils and shim-kernel of the electrical shimming system were constructed and coated with layers of zirconia, thermal epoxy, and silver-paste resin to facilitate passive heat dissipation and ensure mechanical and thermal stability. Furthermore, the 7-channel shim coils were divided into two parts connected in parallel, resulting in a reduction of joule heating temperatures from 96.2 to 32.6 °C. Without the shimming system, the Halbach magnet exhibits a field inhomogeneity of approximately 140 ppm over the sample volume. The probehead was designed to incorporate a solenoidal mini coil, integrated into a single planar board. This design choice aimed to enhance sensitivity, minimize [Formula: see text] inhomogeneity, and reduce impedance discrepancies, transmission loss, and signal reflections. Consequently, the resulting linewidth of water within a 3 mm length and 2.4 mm inner diameter sample volume was 4.5 Hz. To demonstrate the effectiveness of spectral editing in LF-NMR applications at 29.934 MHz, we selectively excited hydroxyl and/or methyl protons in neat acetic acid using optimal control pulses calculated through the Krotov algorithm.

6.
Sensors (Basel) ; 23(9)2023 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-37177486

RESUMEN

Imaging wide-field surface plasmon resonance (SPR) microscopy sensors based on polyacrylic acid polyelectrolyte brushes (PAA PEBs) were designed to enhance the sensitivity of nano-object detection. The switching behavior of the PAA PEBs against changes in the pH values was investigated by analyzing the chemical, morphological, optical, and electrical properties. At pH ~1, the brushes collapse on the surface with the dominance of carboxylic groups (COOH). Upon the increase in the pH to nine, the switching process completes, and the brushes swell from dissociating most of the COOH groups and converting them into COO- groups. The domination of the negatively charged COO- groups increases the electrostatic repulsion in the polymer chains and stretches the brushes. The sensitivity of the SPR sensing device was investigated using a theoretical approach, as well as experimental measurements. The signal-to-noise ratio for a Au layer increases from six to eighteen after coating with PAA PEBs. In addition, the linewidth of the recorded image decreases from six pixels to five pixels by using the Au-PAA layers, which results from the enhanced spatial resolution of the recorded images. Coating a Au-layer with PAA PEBs enhances the sensitivity of the SPR sensing device, and improves the spatial resolution of the recorded image.

7.
Nanomaterials (Basel) ; 13(7)2023 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-37049294

RESUMEN

We fabricated ferroelectric films of the organic molecular diisopropylammonium chloride (DIPAC) using the dip-coating technique and characterized their properties using various methods. Fourier-transform infrared, scanning electron microscopy, and X-ray diffraction analysis revealed the structural features of the films. We also performed ab-initio calculations to investigate the electronic and polar properties of the DIPAC crystal, which were found to be consistent with the experimental results. In particular, the optical band gap of the DIPAC crystal was estimated to be around 4.5 eV from the band structure total density-of-states obtained by HSE06 hybrid functional methods, in good agreement with the value derived from the Tauc plot analysis (4.05 ± 0.16 eV). The films displayed an island-like morphology on the surface and showed increasing electrical conductivity with temperature, with a calculated thermal activation energy of 2.24 ± 0.03 eV. Our findings suggest that DIPAC films could be a promising alternative to lead-based perovskites for various applications such as piezoelectric devices, optoelectronics, sensors, data storage, and microelectromechanical systems.

8.
Metabolites ; 13(3)2023 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-36984792

RESUMEN

The ability to monitor the dynamics of stem cell differentiation is a major goal for understanding biochemical evolution pathways. Automating the process of metabolic profiling using 2D NMR helps us to understand the various differentiation behaviors of stem cells, and therefore sheds light on the cellular pathways of development, and enhances our understanding of best practices for in vitro differentiation to guide cellular therapies. In this work, the dynamic evolution of adipose-tissue-derived human Mesenchymal stem cells (AT-derived hMSCs) after fourteen days of cultivation, adipocyte and osteocyte differentiation, was inspected based on 1H-1H TOCSY using machine learning. Multi-class classification in addition to the novelty detection of metabolites was established based on a control hMSC sample after four days' cultivation and we successively detected the changes of metabolites in differentiated MSCs following a set of 1H-1H TOCSY experiments. The classifiers Kernel Null Foley-Sammon Transform and Kernel Density Estimation achieved a total classification error between 0% and 3.6% and false positive and false negative rates of 0%. This approach was successfully able to automatically reveal metabolic changes that accompanied MSC cellular evolution starting from their undifferentiated status to their prolonged cultivation and differentiation into adipocytes and osteocytes using machine learning supporting the research in the field of metabolic pathways of stem cell differentiation.

9.
Nanomaterials (Basel) ; 13(6)2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36985864

RESUMEN

Surface atomic arrangement and physical properties of aluminum ultrathin layers on c-Si(111)-7 × 7 and hydrogen-terminated c-Si(111)-1 × 1 surfaces deposited using molecular beam epitaxy were investigated. X-ray photoelectron spectroscopy spectra were collected in two configurations (take-off angle of 0° and 45°) to precisely determine the surface species. Moreover, 3D atomic force microscopy (AFM) images of the air-exposed samples were acquired to investigate the clustering formations in film structure. The deposition of the Al layers was monitored in situ using a reflection high-energy electron diffraction (RHEED) experiments to confirm the surface crystalline structure of the c-Si(111). The analysis of the RHEED patterns during the growth process suggests the settlement of aluminum atoms in Al(111)-1 × 1 clustered formations on both types of surfaces. The surface electrical conductivity in both configurations was tested against atmospheric oxidation. The results indicate differences in conductivity based on the formation of various alloys on the surface.

10.
Cureus ; 15(12): e51393, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38292976

RESUMEN

Colorectal cancer is a common malignancy, with the liver being the most frequent site of metastases. [18F] Fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) has emerged as a valuable tool in detecting and evaluating liver metastases and extrahepatic disease. Herein, we present a case of a 76-year-old male with colorectal cancer associated with lung and liver metastases. The patient received 12 chemoimmunotherapy cycles and was then put on maintenance cetuximab; serial [18F]FDG PET/CT scans were utilized to evaluate treatment response. The patient exhibited a positive response to chemoimmunotherapy, with regression of rectal disease and resolution of pulmonary metastatic nodules. Serial [18F]FDG PET/CT scans unveiled three distinct necrotic patterns. The case report advocates that [18F]FDG PET/CT plays an important role in evaluating colorectal liver metastases (CRLM) response to treatment, identifying transient necrosis, early recurrence, and emphasizing the limitations of post-treatment CT scans in identifying early CRLM recurrence. Integrating functional imaging, particularly [18F]FDG PET/CT, promises for management monitoring and surveillance of CRLM patients.

11.
Biosensors (Basel) ; 12(12)2022 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-36551089

RESUMEN

Complex composite films based on polyaniline (PANI) doped hydrochloric acid (HCl) incorporated with aluminum nitrate (Al(NO3)3) on Au-layer were designed and synthesized as a surface plasmon resonance (SPR) sensing device. The physicochemical properties of (PANI-HCl)/Al(NO3)3 complex composite films were studied for various Al(NO3)3 concentrations (0, 2, 4, 8, 16, and 32 wt.%). The refractive index of the (PANI-HCl)/Al(NO3)3 complex composite films increased continuously as Al(NO3)3 concentrations increased. The electrical conductivity values increased from 5.10 µS/cm to 10.00 µS/cm as Al(NO3)3 concentration increased to 32 wt.%. The sensitivity of the SPR sensing device was investigated using a theoretical approach and experimental measurements. The theoretical system of SPR measurement confirmed that increasing Al(NO3)3 in (PANI-HCl)/Al(NO3)3 complex composite films enhanced the sensitivity from about 114.5 [Deg/RIU] for Au-layer to 159.0 [Deg/RIU] for Au-((PANI-HCl)/Al(NO3)3 (32 wt.%)). In addition, the signal-to-noise ratio for Au-layer was 3.95, which increased after coating by (PANI-HCl)/Al(NO3)3 (32 wt.%) complex composite layer to 8.82. Finally, we conclude that coating Au-layer by (PANI-HCl)/Al(NO3)3 complex composite films enhances the sensitivity of the SPR sensing device.


Asunto(s)
Compuestos de Anilina , Resonancia por Plasmón de Superficie , Compuestos de Anilina/química , Compuestos de Aluminio , Ácido Clorhídrico/química
12.
Comput Struct Biotechnol J ; 20: 2965-2977, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35782733

RESUMEN

Most metabolic profiling approaches focus only on identifying pre-known metabolites on NMR TOCSY spectrum using configured parameters. However, there is a lack of tasks dealing with automating the detection of new metabolites that might appear during the dynamic evolution of biological cells. Novelty detection is a category of machine learning that is used to identify data that emerge during the test phase and were not considered during the training phase. We propose a novelty detection system for detecting novel metabolites in the 2D NMR TOCSY spectrum of a breast cancer-tissue sample. We build one- and multi-class recognition systems using different classifiers such as, Kernel Null Foley-Sammon Transform, Kernel Density Estimation, and Support Vector Data Description. The training models were constructed based on different sizes of training data and are used in the novelty detection procedure. Multiple evaluation measures were applied to test the performance of the novelty detection methods. Depending on the training data size, all classifiers were able to achieve 0% false positive rates and total misclassification error in addition to 100% true positive rates. The median total time for the novelty detection process varies between 1.5 and 20 seconds, depending on the classifier and the amount of training data. The results of our novel metabolic profiling method demonstrate its suitability, robustness and speed in automated metabolic research.

13.
Asian Pac J Cancer Prev ; 23(5): 1529-1537, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35633535

RESUMEN

OBJECTIVES: In this work, 9 lipophilic-acid chelating FQs (fluoroquinolones) comprising chelating groups  have been prepared, characterized and screened for in vitro cytotoxicity, radical scavenging and antiinflammation propensities. METHODS: Using sulforhodamine B colorimetric bioassay vs. cisplatin; FQs-inflicted reductions' of viability against breast T47D and MCF7, Pancreatic PANC-1, colorectal HT29, HCT116, SW620, CACO2, SW480 and Leukaemia K562 cancer cell lines were examined in quadruplicates/dose/cell line. Parameters including potency, toxicity, and selectivity (potency/toxicity) have been reported along with DPPH- and NO- radicals' scavenging capacities -as their molecular action mechanism- in comparison to ascorbic acid and indomethacin respectively. Using Griess assay in Lipopolysaccharide (LPS) prompted RAW264.7 macrophages; mitigation of inflammation was investigated. RESULTS: nitroFQ 3b, unlike the rest of FQs in PANC1 and MCF7 cells, exhibited remarkably superior NO-radical scavenging/antiinflammation capacity to indomethacin with respective antiproliferative IC50 values (<50µM) 49 vs. cisplatin's 122 and 6 vs. cisplatin's 28 (p<0.01-0.001; n=4). Reduced FQ 4b of significantly dual DPPH-NO scavenging propensities exerted exceptionally substantial micromolar antiproliferation in colorectal cancer cells with respective antiproliferative IC50 values (<50µM) of HCT116 0.84< HT29 1.6

Asunto(s)
Antineoplásicos , Neoplasias , Antiinflamatorios , Antineoplásicos/química , Antineoplásicos/farmacología , Células CACO-2 , Cisplatino/farmacología , Fluoroquinolonas/química , Humanos , Indometacina
14.
Anticancer Agents Med Chem ; 22(19): 3304-3321, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35570520

RESUMEN

BACKGROUND: Incidence rates and prevalence of cancer are substantially high globally. New safe therapeutic drugs are endorsed to overcome the high toxicity and poor safety profile of clinical anticancer agents. OBJECTIVE: As antineoplastic Vosaroxin is a commercial fluoroquinolone (FQ), we hypothesize that superlative antiproliferation activity of lipophilic FQs/TFQs series correlates to their acidic groups and C8-C7 ethylene diamine Chelation Bridge along with bulky dual halogenations. METHODS: We tested dual lipophilic- acidic chelating FQs with a genuine potential of antiproliferative propensities based on their dual DPPH- and NO- radicals scavenging biocapacities using cell based - and colorimetric assays vs. respective reference agents as their molecular action mechanism. RESULTS: In this work, 9 lipophilic-acid chelating FQs and their cyclized TriazoloFQs (TFQs) designed to bear 7- dihaloanilino substituents with a special focus on dichlorosubstitutions have been prepared, characterized and screened against breast T47D and MCF7, Pancreatic PANC1, colorectal HT29, cervical HELA, lung A375, skin A549, and Leukaemia K562 cancer cell lines using sulforhodamine B colorimetric bioassay. Parameters including potency, toxicity, and selectivity (potency/toxicity) have been reported along with DPPH- and NO- radicals' scavenging propensities - as their molecular action mechanism- in comparison to ascorbic acid and indomethacin, respectively. Using Griess assay in lipopolysaccharide (LPS) prompted RAW264.7 macrophages inflammation, IC50 values (µM) in the ascending order of new FQs' NO scavenging/antiinflammation capacity were 4a < 3a < 4c < indomethacin (23.8 < 33.4 < 36 vs. indomethacin's 124, respectively). Exceptionally unlike the rest, reduced FQ, 4b exhibited remarkably superior DPPH radical scavenging capacity to ascorbic acid (IC50 values (µM) 19.9 vs. 123.9, p < 0.001). In comparison to cisplatin; nitroFQs (3a, 3b and 3c), the reduced FQs (4a, 4b, and 4c) and the TFQs (5a, 5b and 5c) exerted substantial micromolar antiproliferation IC50 values < 50 µM in cervical Hela cancer cells but lacked comparable bioactivity in leukaemia K562. In both breast MCF7 and T47D cancer cell lines, FQs/TFQs 4a < 3a < 5b (respective IC50 values (µM) 0.52 < 22.7 < 24 vs. cisplatin's 41.8 and 0.03 < 4.8 < 27 vs. cisplatin's 509), and in both GI system colorectal HT29 and pancreatic PANC1 cancer cells FQs/TFQs 4a < 3a < 5b and 4a< 3a (respective IC50 values (µM) 0.12 < 3.5 < 15.9 vs. cisplatin's 148 and 1.5 < 10.4 vs. cisplatin's 25.5), exerted nanomolar-micromolar affinities of antiproliferation potencies < 50µM. Besides in lung A375 cancer cells FQs/TFQs 4c < 4a < 3a and in skin A549 cancer cells 5c < 3c < 4a < 3a < 4c (respective IC50 values (µM) 0.07 < 3.2 < 10.3 vs. cisplatin's 390 and 0.5 < 2.3 < 3.8 < 8.8 < 17.3 vs. cisplatin's 107) exhibited nanomolar-micromolar antineoplastic capacities < 50 µM. Their spectrum of selectivity indices for safety in fibroblasts PDL-based 72h incubations was reported. Unequivocally 4b reduction of viability effectiveness linked with its DPPH radical scavenging effects (without a matching antiinflammation effect). Explicitly 4a, 3a and 4c exerted exquisite antiinflammation-selective cytotoxicity duality in vitro. CONCLUSION: Such a new potential chelation mechanism can explain the pronounced difference in antineoplastic activity of new FQs/TFQs.


Asunto(s)
Antineoplásicos , Neoplasias Colorrectales , Leucemia , Antiinflamatorios/farmacología , Antineoplásicos/química , Antineoplásicos/farmacología , Ácido Ascórbico/farmacología , Proliferación Celular , Cisplatino/farmacología , Diaminas , Ensayos de Selección de Medicamentos Antitumorales , Etilenos/farmacología , Fluoroquinolonas/química , Fluoroquinolonas/farmacología , Humanos , Indometacina/farmacología , Lipopolisacáridos/farmacología , Estructura Molecular , Relación Estructura-Actividad
15.
Heliyon ; 8(1): e08683, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35028463

RESUMEN

We report on the synthesis and characterization of Cu2ZnSnS4 (CZTS) thin films prepared at different annealing temperatures using the sol-gel method and deposited on glass substrates using the immersing method. The XRD analysis demonstrates that the films annealed at 450 °C exhibit the most stable tetrahedral kesterite structure. Computationally, the Vienna ab initio simulation package (VASP) has been implemented to calculate critical structural properties of as-prepared CZTS) thin films and compared with those extracted from the XRD patterns. An excellent agreement is obtained between the calculated and measured structural parameters. Optical measurement of key optical parameters of annealed CZTS thin films shows a drastic manipulation of all-optical properties compared to the as-prepared thin films. In particular, an optical band gap of 1.62 eV obtained for annealed CZTS thin films at 450 °C makes them eligible to be potential candidates for thin film-based high-efficiency solar cells. Calculations of elastic properties of annealed thin films reveal that crystallite size increases and microstrain decrease compared with those of as-prepared thin films. The sheet resistance of annealed CZTS thin films exhibits a significant decline as the annealing temperature is increased. The electrical properties of annealed CZTS thin films could match some conductors. Remarkably, at 450 °C annealing temperature, the sheet resistance decreases to 74 Ω.cm-1 indicating the possibility of using the annealed CZTS thin films for efficient and low cost solar cell applications.

16.
Photochem Photobiol ; 98(4): 831-842, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34614230

RESUMEN

The photoisomerization kinetics of photoswitchable thin films based on nanostructure/molecular layers of AlN-AO7 have been studied, investigated and reported. The trans → cis isomerization process occurs by UV-light irradiation. The cis-isomer could be turned back to the trans-isomer by either thermal or optical relaxation. The kinetics and time-evolution of the photoisomerization and reverse isomerization mechanism of AlN-AO7 thin films are investigated by UV-Vis absorbance spectra using relevant models. All phases of AlN-AO7 thin film, initial trans-, cis-, optical trans-, thermal trans-phases, were investigated using UV-Vis absorbance spectra, FTIR spectra, XRD and SEM. Transforming AlN-AO7 thin film from the initial trans-phase into cis-phase leads to curvature in the AO7 leaves and increases in the strain inside the structure. Going back to the trans-phase by either optical or thermal relaxation leads to vanishing the curvature and decreasing the structure's strain. Finally, the energy storage capacity was calculated using DSC and was found to be 36.38 J g-1 , simultaneously realizing the multisource solar energy storage and environmental heat.

17.
Photochem Photobiol ; 98(4): 823-830, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-34612527

RESUMEN

Azobenzene has attracted substantial attention as a photoswitchable molecule since its applications range from energy and data storage to biomedical applications. This work reports a new type of thin-film based on azobenzene derivative anchored to cerium oxide nanoparticles CeO2 NPs for photoswitching applications. The trans-cis isomerization and reverse isomerization occur by UV-light exposure and thermal relaxation process, respectively. The photoisomerization and reverse isomerization kinetics for CeO2 NPs-MR thin films are studied, investigated, and analyzed using UV-Vis absorbance spectra, FTIR spectroscopy, XRD, and scanning electron microscopy (SEM), in addition to differential scanning calorimetry (DSC) measurement to study the energy storage capacity. The results found that anchoring azobenzene to CeO2 NPs is successful in multisource storage of solar energy applications.


Asunto(s)
Nanopartículas del Metal , Compuestos Azo , Nanopartículas del Metal/química , Microscopía Electrónica de Rastreo , Espectroscopía Infrarroja por Transformada de Fourier
18.
Comput Struct Biotechnol J ; 19: 5047-5058, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34589182

RESUMEN

Metabolomics is an expanding field of medical diagnostics since many diseases cause metabolic reprogramming alteration. Additionally, the metabolic point of view offers an insight into the molecular mechanisms of diseases. Due to the complexity of metabolic assignment dependent on the 1D NMR spectral analysis, 2D NMR techniques are preferred because of spectral resolution issues. Thus, in this work, we introduce an automated metabolite identification and assignment from 1H-1H TOCSY (total correlation spectroscopy) using real breast cancer tissue. The new approach is based on customized and extended semi-supervised classifiers: KNFST, SVM, third (PC3) and fourth (PC4) degree polynomial. In our approach, metabolic assignment is based only on the vertical and horizontal frequencies of the metabolites in the 1H-1H TOCSY. KNFST and SVM show high performance (high accuracy and low mislabeling rate) in relatively low size of initially labeled training data. PC3 and PC4 classifiers showed lower accuracy and high mislabeling rates, and both classifiers fail to provide an acceptable accuracy at extremely low size (≤9% of the entire dataset) of initial training data. Additionally, semi-supervised classifiers were implemented to obtain a fully automatic procedure for signal assignment and deconvolution of TOCSY, which is a big step forward in NMR metabolic profiling. A set of 27 metabolites were deduced from the TOCSY, and their assignments agreed with the metabolites deduced from a 1D NMR spectrum of the same sample analyzed by conventional human-based methodology.

19.
Polymers (Basel) ; 13(5)2021 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-33803395

RESUMEN

We report the effect of an iodine filler on photoisomerization kinetics of photo-switchable PEO-BDK-MR thin films. The kinetics of photoisomerization and time progression of PEO-BDK-MR/I2 nanocomposite thin films are investigated using UV-Vis, FTIR spectroscopies, and modified mathematical models developed using new analytical methods. Incorporating iodine filler into the PEO-BDK-MR polymeric matrix enhances the isomerization energy barrier and considerably increases the processing time. Our outcomes propose that enhanced photoisomerized and time processed (PEO-BDK-MR)/I2 thin films could be potential candidates for a variety of applications involving molecular solar thermal energy storage media.

20.
Heliyon ; 7(1): e05952, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33506128

RESUMEN

We synthesize and optically characterize pure PMMA and PMMA incorporated with metal oxides nanoparticles (MO NPs) such as ZnO, CuO, TiO2 and SiO2 NPs nanocomposite thin films with weight concentration of 10% using dip-coating technique. SEM images of MO NPs show that all NPs have nearly an average size of around 50 nm. The optical parameters such as, optical parameters (n and k), optoelectronics properties, dispersion, band-gap energy and band structure of as-prepared nanocomposite thin films were determined by analyzing the transmittance and reflectance spectra. Mainly, optical band-gap energy (E g) and the thickness of thin films are evaluated to a high degree of accuracy by utilizing Q-functional derived using a mathematical model recently published. The Q(E) is a functional containing experimental transmission and reflection data and the incident photon energy. The E g value of un-doped PMMA thin films is found to be 4.273 eV. This value decreases as pre-selected MO NPs are introduced into thin films. These values are in excellent agreement with those determined using Tauc method. The FTIR technique is employed to elucidate the vibrational bands of the nanocomposites and the intermolecular bonding between PMMA matrix and the MOs NPs. Thermal stability is investigated by employing thermogravimetric analysis (TGA) at temperatures up to 400 °C. The obtained TGA thermograms indicate that adding MOs NPs to PMMA yield thin films of better thermal stability. The obtained doped thin films show a great promise for fabricating high-efficient optoelectronic devices.

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