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En el presente trabajo realizamos el estudio de reactividad para astragalina y aliina en el nivel de teoría semiempírico PM7 en la fase acuosa y empleando parámetros de reactividad global derivados de la Teoría de los funcionales de la densidad. Los resultados indican que aliina es mejor electrófilo, mientras que astragalina es una especie menos mutagénica. Se analizó también la capacidad de estos compuestos para acoplarse al proteasa MPro del SARS-COV-2 con la intención de determinar su potencial para inhibir la replicación de este virus. A partir del estudio de acoplamiento molecular Se evaluaron las afinidades de unión de los complejos y los valores de ΔG obtenidos para aliina y astragalina fueron -6.77 kcal mol-1 y -8.52 kcal mol-1, respectivamente. Aliina mostró interacciones con la proteasa principal (Mpro) del SARS-CoV-2 de tipo van der Waals con los residuos CYS145 y HSD164 que presentan la actividad catalítica Mpro del SARS-CoV-2. Por otro lado, astragalina interactúa con la proteasa mediante puentes de hidrógeno e interacciones tipo π-alquil con el residuo CYS145 y con HSD164 por interacción de enlaces de carbón. Estos resultados sugieren que los metabolitos aliina y astragalina interactúan con el bolsillo catalítico de la proteasa por lo que podrían actuar como inhibidores de la replicación del virus SARS-CoV-2.

En este trabajo, se comparó el comportamiento experimental presión-temperatura en la transición de fase Isotrópico-Nemático para el Cristal Líquido 4-4´-bis(heptyloxy)azoxybenzene (HOAOB) a 1 atm utilizando un desarrollo del Modelo Convex Peg HERSW. Se calcularon los valores de los volúmenes moleculares para la coraza dura y atractiva respectivamente, por medio de cálculos mecano cuánticos a los niveles de teoría y precisión numérica PM3, PM6, Teoría de funcionales de la Densidad al nivel de teoría y precisión numérica B3LYP/6-311++G(d,p) y B3LYP/6-311++G(d,p)//PM6 considerando las interacciones intermoleculares entre monómeros (de moléculas de HOAOB) de un heptámetro (HOAOB)7. Se encontró que la mejor predicción teórica de los datos experimentales se encuentra cuando se incorpora el efecto de la correlación electrónica al cálculo del volumen con el modelo IPCM.

In this work, we have analyzed of density-pressure-temperature behavior of the EBBA liquid crystal at 1 atm by using first-order perturbation theory for Convex Peg HERSW model. We predicted quantitatively the experimental density-temperature behavior in this region of the diagram phase with and , and with and .

En el presente trabajo realizamos un estudio voltamperométrico del proceso de depósito de cobalto sobre un substrato de oro a partir de un baño electrolito de base de bitartratos y de composición CoCl2 0.01 M + KC4H5O6 0.05 M. Los resultados indican que, a partir del sistema estudiado, el cobalto se puede electro depositar en el rango de potencial ubicado entre -0.5 a -0.9 V. El comportamiento de la corriente de pico vs la velocidad de barrido1/2, sugiere un proceso controlado por difusión. En donde el valor del coeficiente de difusión es 8.2x10-8 cm2 s-1

In this work, we have analyzed of density-pressure-temperature behavior at the Isotropic-Nematic phase transition of the 5CB liquid crystal at 1 atm by using a first-order perturbation theory for Convex Peg HERSW model. We predicted quantitatively the experimental behavior in this region of the diagram phase. En este trabajo, hemos analizado el comportamiento densidad-presion-temperatura en la transicion de fase Isotropica-Nematica del cristal liquido 5CB a 1 atm utilizando una teoria de perturbacion de primer orden para el modelo Convex Peg HERSW. Predecimos cuantitativamente el comportamiento experimental en esta region del diagrama de fase.

Metalloporphyrins (MP) and metallophtalocyanines (MPc) are innovative materials with catalytic properties that have attracted attention for their application for diverse electrochemical purposes. The presence of metallic centers in their structure offers a redox-active behavior that is being applied in the design of solid electrodes for the quantification of biomolecules, water contaminants, and pharmaceuticals, among others. Herein, we collect the recent information about porphyrin and phthalocyanine complexes as modifiers of electrodes, and the important aspects of the design, characterization, and application of these electrodes.

En el presente trabajo se reporta la simulación de la respuesta voltamperométrica y cronoamperométrica de un biosensor multienzimático para la cuantificación simultánea de glucosa, colesterol y triglicéridos con un solo dispositivo. Los resultados fueron procesados mediante regresión lineal múltiple MLR, regresión de componentes principales PCR y regresión de mínimos cuadrados parciales PLS, encontrando que se obtienen los mejores resultados con MLR procesando la información voltamperométrica, obteniendo porcentajes de error relativo menores al 10% en promedio

A new amlodipine-chitosan nanocomposite was built using amlodipine nanoparticles as primary scaffolds by spontaneous emulsification, and its complete elucidation was performed by using several spectrometric techniques. Our results indicate that the amlodipine-chitosan nanocomposite has better solubility than amlodipine at pH 7.4 with a nearly all the drug substance dissolved (97%) by the final time-point measured. The docking study support the existence of intermolecular interactions are established between amlodipine and chitosan.

In this work, it is proposed a perturbation theory in conjunction with the Convex Peg HERSW model and an adjustable intermolecular potential. The perturbation theory developed can quantitatively predict the density–pressure–temperature experimental behavior at the isotropic–nematic phase transition of MBBA at 1 atm.

In recent years, iron oxide nanoparticles have demonstrated great potential in biomedical applications due to their non-toxic role in biological systems. Also, the magnetic and semiconductor properties of iron oxide nanoparticles can lead to multifunctional applications in medicine. These nanoparticles have been developed as antibacterial, antifungal, and anticancer. For cancer treatment and diagnosis, iron oxide nanoparticles have been functionalized with drugs. However, many of those drugs have been related to adverse effects on health. On the other hand, phytochemicals from extracts of plants have been used as an alternative for the functionalization of these nanoparticles preventing negative effects. The main advantage of these nanoparticles is the high biodistribution in the organism compared with other drug delivery systems. The magnetism of iron oxide nanoparticles has been used in cancer treatment and diagnosis, for example, thermoablation, hyperthermia, and contrast media in magnetic resonance imaging. Therefore, this work aimed to discuss the methods for the synthesis of iron oxide nanoparticles, the different kinds of coatings used to functionalize them, and the different applications they have had in cancer treatment and diagnosis.

In this work, the chemical reactivity of isoxaflutole (ISOX) and diketonitrile (DKN) was analyzed at the X/6-311++G(2d,2p) (where X = = B3LYP, M06, M06L and ?B97XD) level of theory, in the gas and aqueous phases. The results indicate that DKN, the active metabolite of ISOX, is more stable than isoxaflutole in both phases. ISOX is susceptible to electrophilic and free radical reactions through the isoxazole ring; while the carbonyl group is attacked by nucleophiles. For DKN nucleophilic and free radical attacks are expected on the aromatic ring, while electrophilic attacks are favored on the oxygen atom of the carbonyl groups. The results suggest that the cleavage of the N?O bond in the isoxazole ring is possible through electrophilic and free radical attacks, while electrophilic and free radical attacks will favor substitutions on the carbonyl groups of DKN.

Atomic and magnetic force microscopy were employed in order to investigate the local magnetic state of individual cobalt clusters electrodeposited onto gold electrodes. The analysis indicated that the diameter of the clusters was similar regardless of the potential formation, or growth stage, but the height and surface coverage changed as the potential augmented. Individual examination of the clusters showed that the height determined the magnetic transition from the single to the multi domain state. By using a theoretical single-domain ferromagnetic model in terms of the clusters dimensions, the magnetic exchange constant at different potential voltages was obtained, which was higher than the cobalt bulk value. In addition, a micromagnetic simulation study was employed to validate the experimental results, and it correctly confirmed the experimental magnetic transition. In addition, a fcc crystalline structure and some insights of the clusters growth mechanism on the gold surface were inferred from the results.

In the present, study we analyzed the electronic properties of Steviol, the Stevia rebaudiana metabolite, and its interaction with antiapoptotic protein BCL-2. The ionization potential and electrophilicity index values were evaluated in the framework of the DFT, and these values suggest that Steviol may form ligand-receptor interactions. Also, the bond dissociation energy and the electrostatic potential distribution of Steviol reveal its antioxidant behavior. Docking studies were performed to evaluate the feasibility of this molecule to interact with antiapoptotic protein BCL-2. However, no hydrogen bonds were found in the pocket site, instead six interactions, including alkyl and π-alkyl type were formed, suggesting that the possible most feasible mechanism for anticancer activity would be through free radicals scavenging.

Background:Diclofenac is a widely used nonsteroidal anti-inflammatory drug. Recent studies have shown that frequent consumption of this drug in high concentrations can cause heart diseases, so strict control of diclofenac’s quantity in commercial drugs is necessary. This paper presents the development of an optimized voltammetric methodology for the quantification of diclofenac, which offers some advantages over other electrochemical and accepted methods.Objective:Optimize with a Box-Behnken design the differential pulse voltammetry parameters towards the quantification of diclofenac in pharmaceutical samples.Methods:Diclofenac behavior in the working electrode was evaluated by cyclic voltammetry, in order to stablish the best conditions for diclofenac’s quantification. A Box-Behnken design was then used to optimize the differential pulse voltammetry parameters and stablish the analytical behavior of the proposed methodology. Commercial tablets were prepared for analysis according to the Pharmacopeia, the DPV optimized methodology was used to quantify diclofenac in the samples, and the results were statistically compared with those obtained with the official methodology.Results:After optimization, the analytical parameters found were: correlation coefficient of 0.998, detection limit of 0.001 µM, quantification limit of 0.0033 µM and sensitivity of 0.299 µA.µM-1. The statistical analysis showed there were no significant differences between the results obtained with the proposed methodology and those obtained with the official methodology.Conclusion:The statistical analysis showed that the proposed methodology is as reliable as the official spectrophotometric one for the quantification of diclofenac in commercial drugs, with very competitive analytical parameters, and even better to others found with more complex electrodes.

In this work, we report the electrochemical synthesis of nanometric copper clusters smaller than 3 nm of height and 14.3 nm of diameter from perchlorate solutions. From the number of copper clusters counted directly from the AFM (Atomic force microscopy) images, it was possible to derive an equation, which is able to predict the number of clusters formed in function on the applied potential. Also, qualitative AFM images were simulated employing a spreadsheet and the freeware ImageJ, the results obtained show concordance with the experimental AFM images.

In the present work, the influence of the concentration of bitartrate ions (HT) on the copper electrodeposition process was analyzed. The study was carried out from an aqueous solution containing 0.001 M of CuX (where X = (NO3–)2 ,(Cl–)2, SO42–) and x M KHT (where x = 0.005 M, 0.01 M, and 0.015 M). From voltammetric and chronoamperometric studies, the results indicate that copper electrodeposition is a diffusion-controlled process. The current density transients were well described through a kinetic mechanism involving capacitive and faradaic contributions. The diffusion coefficient values of Cu1+ and Cu2+ result to be similar at the different concentration values of potassium bitartrate used in this work. This work is licensed under a Creative Commons Attribution 4.0 International License.

Fucooligosaccharides comprise the primary group of human milk oligosaccharides. Due to their beneficial properties, a series of synthetic methods have been proposed to obtain them. Enzy- matic methods show great promise, and α-L-fucosidase from Thermotoga maritima has emerged as a powerful catalyst for their production. Nonetheless, the enzyme’s limited substrate scope has de- layed its wider application. The present work aims to compare the relative reactivity of fucose, pNP-fucose, and ethyl-fucose, while also exploring the molecular interactions of these fucosyl-donors with the enzyme through a combination DFT and docking analysis. The HOMO-LUMO band gaps range from −7.14571 to −4.24429 eV, with α/β-pNP-fucose and α-fucose being the three most reactive compounds. Moderate association energies between −6.4 to −5.5 kcal·mol−1 were found in the dock- ing analysis, with α-pNP-fucose and both anomers of ethyl-fucose demonstrating the poorest affinity. In the case of α/β-lactose affinity to the β-fucose/enzyme complex, no significant differ- ences were shown. We conclude that the best fucosyl-donors for transfucosylation are those that maintain an enzyme affinity and reactivity similar to pNP-fucose.

In this work, a computational chemical study of Etoricoxib was carried out at the X/6311G(d,p) (where X=B3LYP, M06 and ωB97XD) level of theory, at the gas, aqueous and ethanol phases. Through the chemical reactivity descriptors derived from the DFT, it was possible to find that Etoricoxib structure exhibits a major chemical activity in water and ethanol phases in comparison to the gas phase, which suggests this drug would be more active in biological solvents like in blood, tissues and places where the ciclooxigenasa 2 (COX)-2 is found. In addition, a molecular docking analysis was conducted to study the interaction of Etoricoxib with the COX-2 active site. The results suggest that Etoricoxib interacts with 19 amino acid residues inside the COX-2 active site.

Electronic structure calculations were performed to analyze the effectiveness of linking agents (sulfur and nitrogen) in connecting the trans-azobenzene sandwiched between two gold surfaces (Au-atoms). It was analyzed the dynamics of the load carrier and the electronic structure of the molecular backbone by applying an external electric field (EF), also a detailed structural, frontier orbital and natural bond orbital analysis (NBO) were performed. From the NBO analysis, it was possible to predict the path of charge flow in the molecular system. Electrostatic potential mapping allowed us to visualize the charge redistribution in the molecular system caused by the EF application. Our results indicate that when the nitrogen atom is used as a linking agent, the azo group of molecules may enhance their conductivity. This work is licensed under a Creative Commons Attribution 4.0 International License.

A kinetic study of the Ag electrodeposition onto Pt ultramicroelectrodes of 10, 15 and 25 µm of diameter from an aqueous solution containing AgNO3 1 mM + NH4NO3 0.1 M was conducted at overpotential conditions through potentiostatic studies. The analysis of the current density transients indicates the existence of two 2D nucleation and growth processes previous to the 3D nucleation and growth process. This work is licensed under a Creative Commons Attribution 4.0 International License.

A series of five 2-(2-hydroxyphenyl)oxazolo [4,5-b]pyridines (HPOP) (3a-e), where four are novel, were synthesized by a mild, one pot, phenylboronic acid-NaCN catalyzed reaction. Spectroscopic characterization and photophysical properties of these compounds are reported. Absorption and excitation spectra of the compounds were dependent on the substituents in the phenyl ring. Fluorescence quantum yields (0.009–0.538) were associated with the donor strength and the position of the substituents. Also, DFT analysis allowed us to determine the contribution of diethylamino and methoxy moieties to the π-system, which is in agreement with the experimental data analyzed in solution and by cyclic voltammetry. The results obtained in the solid state by single-crystal X-ray diffraction experiments indicate that, the quasi-planarity envisioned for the explored compounds is present, supporting the hypothesis that both the H-bonding of a hydroxyl group to the C N moiety and a donor groups such as diethylamino and methoxy moieties favor an electronic communication. Due to the facile synthesis and their photophysical properties, the novel HPOP 3a-e have potential application as organic semiconductors.

In the present work, the global and local reactivity of S-(4-chlorobenzyl)- N,N-diethylthiocarbamate (TB) and its oxidized derivatives (sulfone (TBSu) and sulfoxide (TBS) were analyzed. In addition, the chemical reactivities of the dechlorinated forms of TB (DTB), TBSu (DTBSu) and TBS (DTBS) were studied. The calculations were performed at the wB97XD/6- -311++G(2d,2p) level of theory in the aqueous phase. The condensed Fukui functions indicated that for TB and DTB, the most preferred sites for donating electron in a reaction are located on the S and N atoms, while the most reactive sites for accepting electrons are associated with the aromatic ring (AR). For TBS and DTBS, the more reactive sites are located on AR, S and AR for nucleophilic, electrophilic and free radical attacks, respectively. In the case of TBSu and DTBSu, the results showed AR to be the more reactive zone for the three kinds of attacks. These last results suggest that cleavage of the C?S bond in TB, TBS and their dechlorinated forms is favored by electrophilic attacks. Additionally, the obtained results suggest that in TB, it is plausible that the cleavage of the C?N is favored on attack of this molecule by electrophiles.

Metal nanoparticles adsorbed on graphene are systems of interest for processes relative to catalytic reactions and alternative energy production. Graphene decorated with Cu-nanoparticles, in particular, could be a good alternative material for electrodes in direct borohydride fuel cells. However our knowledge of this system is still very limited. Based on density functional theory, we have analyzed the interaction of Cun nanoparticles (n = 4, 5, 6, 7, 13) with pristine and defective-graphene. We have considered two types of defects, a single vacancy (SV), and an extended lineal structural defect (ELSD), formed by heptagon-pentagon pairs. Our analysis has revealed the covalent character of the Cun-graphene interaction for pristine- and ELSD-graphene, and a more ionic-like interaction for SV-graphene. Furthermore, our analysis shows that the interaction between the nanoparticles and the graphene is rather local, i.e., only the nanoparticle atoms close to the contact region are involved in the interaction, being the electronic contact region much higher for defective-graphene than for pristine-graphene. Thus, the higher the particle the lower its average electronic and structural distortion.

In the present work, we have analyzed the electrophilic and nucleophilic chemical reactivity of the neutral and anionic chlorophenoxyacetic acid herbicides, 4-CPA, 24D-CPA, 34-CPA and 245T-CPA at the X/6-311++G(2d,2p) level of theory (where X= wB97XD, MPW91B1K and MP2). Chemical reactivity was analyzed in the aqueous phase and employing global and local DFT reactivity descriptors. The structural parameters derived from DFT calculations are equivalent to those obtained at the MP2 level. The Fukui Function values suggest that nucleophilic attacks to the neutral and anionic forms would cause dechlorination on 24D-CPA, 34-CPA and 245T-CPA and hydrogen abstraction in 4-CPA. At pH values lower than 2.7, electrophilic attacks would cause the cleavage of the ether bond in 4-CPA, 24D-CPA and 34-CPA and dechlorination in 245T-CPA. But, at pH > 3.6, electrophiles may cleave the ether bond to start the degradation of the four CPAs.

An electrochemical study of zinc deposition was carried out in baths containing 0.5 M ZnCl2 and 0.4 M H3BO3. From the voltammetric study it was found that, in our experimental conditions, zinc electrodeposition is quasi-reversible and occurs under charge transfer control. The average coefficient diffusion calculated was D = 7.14 × 10-6 cm2s-1 while the standard constant at electrode charge was 8.78 × 10-3 cms-1. The nucleation and growth parameters determined from the potentiostatic study showed that, at bigger overpotentials, a vertical growth is favored, suggesting a dendritic growth. The critical cluster´s size calculated was 2, indicating that each active site is formed by two zinc atoms on the glassy carbon electrode (GCE) surface, while the ΔG for the formation of stable nucleus was 1.35 × 10-20 J/nuclei. The Scanning Electron Microscopy images showed thin platelets of hexagonal crystals and dendrites at lower and higher overpotentials applied, respectively.

In the present work, the chemical reactivity of indaziflam N-[(1R,2S)-2,3-dihydro-2,6-dimethyl-1H-inden-1 yl]-6-[(1R)-1-16 fluoroethyl]-1,3,5-triazine-2,4-diamine so called indaziflam (IND) and its metabolites: triazine indanone (ITI), indaziflam carboxylic acid (ICA) and fluoroethyldiaminotriazine (FDAT) was analyzed. The calculations were performed at the X/6 311++G(2d,2p) (where X=B3LYP, M06, M06L and wB97XD) level of theory, in the aqueous phase. The results indicate that ITI is the more reactive followed by ICA, IND and FDAT. The distribution of the active sites was determined evaluating the Fukui function employing the frozen core and finite difference approximations. For electrophilic attacks, IND shows the more reactive zone on the benzene ring, ITI and ICA on the nitrogen atom in the central section and FDAT on its nitrogen atoms. The more nucleophilic sites for IND are observed on the carbon atoms of triazine, on the carbonyl group for ITI, on the carboxylic group for ICA, and on the nitrogen atoms of triazine for FDAT. For free radical attacks case, the more reactive sites for IND are on the benzene and triazine rings, on the carbonyl group, nitrogen of the central section, and nitrogen atoms of triazine, for ITI, carboxylic group for ICA, and on the nitrogen atoms of triazine ring for FDAT.

In the present study, we performed a computational study to gain insights on the binding mode and high affinity of pregabalin, its inactive isomer (R-pregabalin) and gabapentin when modulating voltage-gated calcium channels. Quantum chemical descriptors were evaluated at two different levels of theory (ωB97XD and B3LYP-D3) for the three molecules. The results show that the three ligands have similar quantum chemical descriptors, suggesting that the affinity is governed by the binding pose and the ability to access the pocket. The binding mode analysis of pregabalin indicates that it is interacting with 12 residues (6 hydrogen bonds) including Arg217, which is key to pregabalin action mechanism. Our results suggest that the electrostatic interactions and the hydrogen bonds between pregabalin and Arg217 could explain its high affinity, highlighting the importance of Arg217 in the pharmacological action.

Uric acid is one of the most important metabolites as its blood levels can help to diagnose important diseases. Tradicionally, uric acid is determined by enzymatic-spectrophotometric techniques, but in recent years new promising alternatives have arisen. This review is devoted to the development over the past decade of non-enzymatic electrochemical studies based on nano-structures of non-noble metal oxides (Fe2O3, CuO, Cu2O, ZnO, NiO, MnO2, CeO2, MgO, SnO2 and Co3O4) for uric acid detection. The proposals showed the application of electrochemical sensors for the determination of uric acid in blood, urine, pharmaceuticals, water, and commercial shellfish. The developed electrodes are based on vitreous carbon electrodes, carbon paste, or screen-printed, mainly modified with nano-structures of metal oxides to electrochemically oxidize uric acid, where the anodic current peak is used as the analytical signal and the results reported are very promising.

This work describes the development of a voltammetric methodology based on a carbon paste electrode enriched with multiwalled carbon nanotubes and TiO2 nanoparticles, for the electrochemical quantification of diclofenac. All stages of the methodology were optimized by a Box-Behnken experimental design. The electrochemical behavior of diclofenac was studied by cyclic voltammetry. Results showed that the oxidation of diclofenac is favored by the presence of both MWCNT and TiO2 nanostructures since a considerable increase in the anodic peak current is observed when compared to a that obtained with a bare carbon paste electrode. Under the optimal values found and with the appropriate statistical analysis, a LOD of 0.33 μM, a LOQ of 1.11 μM, a linear concentration range from 1.1 × 10−6 to 5 × 10−3 M (R2 = 0.9958), and a sensitivity of 0.487 μA.μM−1 were found. The electrode’s response was precise as the reproducibility resulted to be 4.39% (%RSD). Finally, a study of possible interferences was performed, along with the quantification of diclofenac in pharmaceutical samples by the proposed voltammetric methodology. The voltammetric method was validated by comparing the results with those obtained with the UV–vis spectrophotometric method.

Aflatoxins are high-toxic secondary metabolites of Aspergillus fungus, which contaminate food at trace levels. Promising voltammetric methods were developed using mercury electrodes, however, they have negative effects on the environment. This work proposes the development and optimization of a differential pulse voltammetric methodology for the quantification of Aflatoxin B1 through bismuth film electrodes by the reduction of aflatoxin. Aflatoxin B1 reduction is controlled by its diffusion towards the electrode’s surface. Optimal conditions for the preparation of the bismuth film and differential pulse voltammetry were obtained by Box-Behnken experimental designs, considering the maximization of the Aflatoxin B1 cathodic peak current. The LOD and LOQ resulted to be 11.2 ng l−1 and 37.3 ng l−1 respectively. The values for the reproducibility and repeatability as %RSD, using a 38.46 ng l−1 solution of Aflatoxin B1 for the measurements, were 5.3% and 4.6%, respectively. The proposed methodology was statistically validated using certified Aflatoxin B1 standard solutions and milk samples successfully analyzed, demonstrating that the proposed methodology represents a novel, low-cost, environmentally-friendly approach for the quantification of Aflatoxin B1.

It is shown, for the first time, that a bare carbon paste electrode can be used for the simultaneous quantification of anti-inflammatory drugs: naproxen (NPX), diclofenac (DCF) and acetaminophen (ACT) in aqueous media. The analytical features are: 19 ± 7, 4.1 ± 1.9 and 3.7 ± 1.5 μM as detection limits of DCF, NPX and ACT, respectively, while the sensitivity of this quantification was 93.0 ± 0.7, 40.0 ± 0.3, and 54.0 ± 1.8 μA mM−1 for ACT, NPX and DCF, respectively. The analytical performance of this electrode is compared with that reported for the quantification of these drugs using HPLC, diffuse reflectance photometry, and other electrodes.

Semiconductor molecular films based on a gallium phthalocyanine chloride (GaPcCl) and a bidentate amine were prepared by using vacuum thermal evaporation and electrochemical techniques in order to investigate the preferred conduction paths within the films. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were employed to characterize the morphology of the films. The conductivity measurements were performed with two different methods in order to investigate preferential conduction directions. The film transverse conductivity was obtained by using scanning tunneling spectroscopy (STS) and the in-plane film conductivity was measured with a four-point probe system. From spectroscopy measurements, the tunneling conductance (dI/dV) was also obtained. From these results, it was found that the conductive nature of the films was strongly influenced by the deposition technique which in turn defined the morphological characteristics of the film. The evaporated method showed better conductivity response and provided semiconductor characteristics in the film transverse direction with an in-plane ohmic response. Finally, contact angle measurements were performed and showed hydrophobic characteristics in all cases.

Consejo Nacional de Ciencia y Tecnologia (CONACyT) CB-2015-257823 Guanajuato National Laboratory CONACyT 123732 SNI Universidad Autonoma del Estado de Hidalgo

Due to worldwide thrombosis incidence, new anticoagulant drugs have been developed. Therefore, diverse techniques are used to measure this capacity. In this sense, a size-exclusion chromatography method has already proposed, which depends on the fibrin solubilization step. Thus, the work aimed to establish the influence of different fibrin solubilizers on fibrinogen denaturation through theoretical-experimental modeling. Theoretical results showed that the coupling energy for fibrinogen-TCA is lower than that obtained for fibrinogen-urea and fibrinogen-bromide coupling, while experimental results evidenced partial fibrinogen precipitation with TCA, NaBr, and urea, resulting this last the best solubilizer to measure thrombin inhibition.