Photobiomodulation by Infrared Diode Laser: Effects on Intracellular Calcium Concentration and Nitric Oxide Production of Paramecium

In Paramecium, cilia beating is correlated to intracellular calcium concentration ([Ca²⁺]i) and nitric oxide (NO) synthesis. Recent findings affirm that photobiomodulation (PBM) can transiently increase the [Ca²⁺]i in mammalian cells. In this study, we investigated the effect of both 808 and 980 nm diode laser irradiated with flat‐top hand‐piece on [Ca²⁺]i and NO production of Paramecium primaurelia, to provide basic information for the development of new therapeutic approaches. In the experiments, the laser power in CW varied (0.1; 0.5; 1; and 1.5 W) to generate the following respective fluences: 6.4; 32; 64; and 96 J cm^?2. The 6.4 J cm^?2 did not induce PBM if irradiated by both 808 and 980 nm diode laser. Conversely, the 32 J cm^?2 fluence had no effect on Paramecium cells if irradiated by the 808 nm laser, while if irradiated by the 980 nm laser induced increment in swimming speed (suggesting an effect on the [Ca²⁺]i, NO production, similar to the 64 J cm^?2 with the 808 nm wavelength). The more evident discordance occurred with the 96 J cm^?2 fluence, which had the more efficient effect on PBM among the parameters if irradiated with the 808 nm laser and killed the Paramecium cells if irradiated by the 980 nm laser. Lastly, the 980 nm and 64 or 96 J cm^?2 were the only parameters to induce a release of stored calcium.     

Analgesic Effect of Light‐Emitting Diode (LED) Therapy at Wavelengths of 635 and 945 nm on Bothrops moojeni Venom‐Induced Hyperalgesia

Envenoming induced by Bothrops snakes is characterized by drastic local tissue damage involving hemorrhage, myonecrosis and proeminent inflammatory and hyperalgesic response. The most effective treatment is antivenom therapy, which is ineffective in neutralizing the local response. Herein, it was evaluated the effectiveness of light‐emitting diode (LED) at wavelengths of 635 and 945 nm in reducing inflammatory hyperalgesia induced by Bothrops moojeni venom (BmV) in mice, produced by an subplantar injection of BmV (1 μg). Mechanical hyperalgesia and allodynia were assessed by von Frey filaments at 1, 3, 6 and 24 h after venom injection. The site of BmV injection (1.2 cm²) was irradiated by LEDs at 30 min and 3 h after venom inoculation. Both 635 nm (110 mW, fluence of 3.76 J/cm² and 41 s of irradiation time) and 945 nm (120 mW, fluence of 3.8 J/cm² and 38 s of irradiation time) LED inhibited mechanical allodynia and hyperalgesia of mice alone or in combination with antivenom treatment, even when the symptoms were already present. The effect of phototherapy in reducing local pain induced by BmV should be considered as a novel therapeutic tool for the treatment of local symptoms induced after bothropic snake bites.     

Study on continuous (254 nm) and pulsed UV (266 and 355 nm) lights on BVD virus inactivation and its effects on biological properties of fetal bovine serum

Both continuous UV lights and pulsed UV lasers have potentials to inactivate known and emerging viruses. Bovine viral diarrhea virus (BVDV), from the Pestivirus genus, is known to be a common viral contamination in (fetal) bovine serum (FBS). Also, BVDV has been used in the blood product industry as a surrogate for Hepatitis C virus (HCV), due to its similarity in structure and genome. Germicidal UV lamp with the wavelength of 254 nm and Nd:YAG laser (pulsed UV laser) in its third and fourth harmonic with the wavelengths of 355 and 266 nm, respectively, were used. BVDV suspended in PBS or FBS were exposed to different intensities and doses and then reduction in BVDV titer were calculated. To complete inactivation of BVDV suspended in PBS and PBS containing 5% FBS, 1.6 (t = 30 min) and 3.2 (t = 60 min) J/cm² were used. The minimum doses for inactivation of BVDV suspended in PBS with the 355 and 266 nm of pulsed UV laser were 352 and 92.25 J/cm². Also, the minimum doses for inactivation of BVDV suspended in FBS with 355 and 266 nm wavelengths of pulsed UV laser were 704 and 127 J/cm². To evaluate the irradiated FBS quality to support cell culture growth, FBS was treated with the dose of 190.5 J/cm² and 266 nm pulsed UV laser and was used to grow Vero cells, in comparison with a control group. The viability of cells in two groups was identical and the statistical evaluation showed no significant difference in 12 passages.     

Thermodynamic properties of (tetradecane + benzene, + toluene, + chlorobenzene, + bromobenzene, + anisole) binary mixtures at T = (298.15, 303.15, and 308.15) K

Density ρ, viscosity η, and refractive index n_D, values for (tetradecane + benzene, + toluene, + chlorobenzene, + bromobenzene, + anisole) binary mixtures over the entire range of mole fraction have been measured at temperatures (298.15, 303.15, and 308.15) K at atmospheric pressure. The speed of sound u has been measured at T = 298.15 K only. Using these data, excess molar volume V^E, deviations in viscosity Δη, Lorentz–Lorenz molar refraction ΔR, speed of sound Δu, and isentropic compressibility Δk_s have been calculated. These results have been fitted to the Redlich and Kister polynomial equation to estimate the binary interaction parameters and standard deviations. Excess molar volumes have exhibited both positive and negative trends in many mixtures, depending upon the nature of the second component of the mixture. For the (tetradecane + chlorobenzene) binary mixture, an incipient inversion has been observed. Calculated thermodynamic quantities have been discussed in terms of intermolecular interactions between mixing components.     

Densities and volumetric properties of (N-(2-hydroxyethyl)morpholine + ethanol, + 1-propanol, + 2-propanol, + 1-butanol,and + 2-butanol) at (293.15, 298.15, 303.15, 313.15, and 323.15) K

Densities of binary mixtures of N-(2-hydroxyethyl)morpholine with ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol were measured over the entire composition range at temperatures from (293.15 to 323.15) K and atmospheric pressure using a vibrating-tube densimeter. The excess molar volumes, V^E were calculated from density data and fitted to the Redlich–Kister polynomial equation. Apparent molar volumes, partial molar volume at infinite dilution and the thermal expansion coefficient of the mixtures were also calculated. The V^E values were found to be negative over the entire composition range and at all temperatures studied and become less negative with increasing carbon chain length of the alkanols.     

(Vapor + liquid) equilibrium properties of (ethane + ethanol) system at (295, 303, and 313) K

The (vapor + liquid) equilibrium data for binary system of (ethane + ethanol) at three temperatures (295, 303, and 313) K were measured using a designed pressure–volume–temperature (PVT) apparatus. A wide range of pressures, (1 to 5) MPa, were considered for the measurements. The phase composition, saturated density, and viscosity of liquid phase were measured for each pressure and temperature. The experimental (vapor + liquid) equilibrium data were compared with the modeling results obtained using the Peng–Robinson and Soave–Redlich–Kwong equations of state.     

(Liquid + liquid) equilibria of (water + linalool + limonene) ternary system at T = (298.15, 308.15, and 318.15) K

(Liquid + liquid) equilibrium (LLE) data for {water (1) + linalool (2) + limonene (3)} ternary system at T = (298.15, 308.15, and 318.15 ± 0.05) K are reported. The organic chemicals were quantified by gas chromatography using a flame ionisation detector while water was quantified using a thermal conductivity detector. The effect of the temperature on (liquid + liquid) equilibrium is determined and discussed. Experimental data for the ternary mixture are compared with values calculated by the NRTL and UNIQUAC equations, and predicted by means of the UNIFAC group contribution method. It is found that the UNIQUAC and NRTL models provide a good correlation of the solubility curve at these three temperatures, while comparing the calculated values with the experimental ones, the best fit is obtained with the NRTL model. Finally, the UNIFAC model provides poor results, since it predicts a greater heterogeneous region than experimentally observed.     

(Liquid + liquid) equilibria for mixtures of (ethylene glycol + benzene + cyclohexane) at temperatures (298.15, 308.15, and 318.15) K

Experimental (liquid + liquid) equilibrium (LLE) data for a ternary system containing (ethylene glycol + benzene + cyclohexane) were determined at temperatures (298.15, 308.15, and 318.15) K and at atmospheric pressure. The experimental distribution coefficients and selectivity factors are presented to evaluate the efficiency of the solvent for extraction of benzene from cyclohexane. The effect of temperature in extraction of benzene from the (benzene + cyclohexane) mixture indicated that at lower temperatures the selectivity (S) is higher, but the distribution coefficient (K) is rather lower. The LLE results for the system studied were used to obtain binary interaction parameters in the UNIQUAC and NRTL models by minimizing the root mean square deviations (RMSD) between the experimental results and calculated results. Using the interaction parameters obtained, the phase equilibria in the systems were calculated and plotted. The NRTL model fits the (liquid + liquid) equilibrium data of the mixture studied slightly better. The root mean square deviations (RMSDs) obtained comparing calculated and experimental two-phase compositions are 0.92% for the NRTL model and 0.95% for the UNIQUAC model.     

Isothermal and isobaric (vapour + liquid) equilibria of (N,N- dimethylformamide + 2-propanol + 1-butanol)

The isothermal and isobaric (vapour  +  liquid) equilibria (v.l.e.) for (N, N - dimethylformamide  +  2-propanol  +  1-butanol) and the binary constituent mixtures were measured with an inclined ebulliometer. The experimental results are analyzed using the UNIQUAC equation with temperature-dependent binary parameters. The comparison between the experimental and literature results for binary systems is given. The ternary v.l.e. values are predicted from the binary results.     

(Vapour + liquid) equilibria,densities, excess molar volumes,refractive indices,speed of sound for (methanol + allyl acetate) and (vinyl acetate + allyl acetate)

Isobaric (vapour  +  liquid) equilibria were determined atp =  101.3 kPa for {methanol  +  allyl acetate (3-acetoxy-1-propene)} and {vinyl acetate (1-acetoxyethylene)  +  allyl acetate}. The thermodynamic consistency of the experimental data was determined with a modified Dechema test. The activity coefficients were correlated with Margules, van Laar, NRTL, UNIQUAC, Wilson and ASOG. Densities, excess molar volumes, refractive indices, speed sounds and changes of refractive index and speed sound on mixing have been determined at 298.15 K and the results fitted to Redlich–Kister polynomials. Allyl acetate can be a possible solvent for extractive distillation.     

Measurement of (liquid + liquid) equilibria for ternary systems of (N-formylmorpholine + benzene + cyclohexane) at temperatures (303.15, 308.15, and 313.15) K

This work demonstrates the ability of N-formylmorpholine (NFM) to act as an extraction solvent for the removal of benzene from its mixture with cyclohexane. The (liquid + liquid) equilibria (LLE) were measured for a ternary system of {N-formylmorpholine (NFM) + benzene + cyclohexane} under atmospheric pressure and at temperatures (303.15, 308.15, and 313.15) K. The experimental distribution coefficients (K) and selectivity factors (S) were obtained to reveal the extractive effectiveness of the solvent for separation of benzene from cyclohexane. The LLE results for the system studied indicate that increasing temperature decreases selectivity of the solvent. The reliability of the experimental results was tested by applying the Othmer–Tobias correlation. In addition, the universal quasichemical activity coefficient (UNIQUAC) and the non-random two liquids equation (NRTL) were used to correlate the LLE data using the interaction parameters determined from the experimental data. The root mean square deviations (RMSDs) obtained comparing calculated and experimental two-phase compositions are 0.0367 for the NRTL model and 0.0539 for the UNIQUAC model.     

(P, Vm, T) Measurements of (octane + 1-chlorohexane) at temperatures from 298.15 K to 328.15 K and at pressures up to 40 MPa

Densities were measured for the liquid octane and 1-chlorohexane, and for nine of their mixtures at four temperatures between 298.15 K and 328.15 K and at pressures up to 40 MPa. An apparatus for density measurements of liquids and liquid mixtures whose main part is a high-pressure vibrating-tube densimeter working in a static mode was used for the measurement. The density data were fitted to the Tait equation and the isothermal compressibilities were calculated with the aid of this equation. Excess molar volumes were also computed from the densities and fitted to the Redlich–Kister equation.     

Permittivity and electric conductivity of aqueous alumina (40 nm) nanofluids at different temperatures

Aiming to study the effect of nanoparticle size on electric properties, the effective relative permittivity and electric conductivity of suspensions of 40 nm particles of aluminium oxide (alumina) in base Milli-Q and Milli-Ro water were determined at six different temperatures in the range (298.15 to 348.15) K, and at eight different concentrations up to 7% mass (2% volume). Present results are compared with previously published values for the same colloids containing 15 nm particles. Empirical equations for describing the experimental data are given. This study demonstrates the importance of the particle size, volume fraction of nanoparticles, temperature and water purity on the effective relative permittivity and electric conductivity of alumina nanoparticles suspensions. Trends for changes in permittivity enhancement and in electric conductivity enhancement with temperature and concentration are examined and discussed. Classical theoretical models in the study of permittivity and conductivity are applied. A summary is given for the effect of size ((15 and 40) nm), concentration (0.25 to 2)% volume and temperature (298.15 to 348.15) K on the behavior of these nanofluids.     

Phase transitions on (liquid + liquid) equilibria for (water + 1-methylnaphthalene + light aromatic hydrocarbon) ternary systems at T = (563, 573, and 583) K

Phase transitions for (water + 1-methylnaphthalene + light aromatic hydrocarbon) ternary systems are observed at their (liquid + liquid) equilibria at T = (563, 573, and 583) K and (8.6 to 25.0) MPa. The phase transition pressures at T = (563, 573, and 583) K were measured for the five species of light aromatic hydrocarbons, o-, m-, p-xylenes, ethylbenzene, and mesitylene. The measurements of the phase transition pressures were carried out by changing the feed mole fraction of water and 1-methylnaphthalene in water free, respectively. Effects of the feed mole fraction of water on the phase transition pressures are very small. Increasing the feed mole fraction of 1-methylnaphthalene results in decreasing the phase transition pressures at constant temperature. The slopes depending on the feed mole fraction for 1-methylnaphthalene at the phase transition pressures are decreased with increasing temperature for (water + 1-methylnaphthalene + p-xylene), (water + 1-methylnaphthalene + o-xylene), and (water + 1-methylnaphthalene + mesitylene) systems. For xylene isomers, the highest and lowest of the phase transition pressures are obtained in the case of p- and o-xylenes, respectively. The phase transition pressures for ethylbenzene are lower than those in the case of p-xylene. The similar phase transition pressures are given for p-xylene and mesitylene.     

Excess volumes of mixing in (N,N-dimethylacetamide + methanol + water) and (N,N-dimethylacetamide + ethanol + water) at the temperature 313.15 K

Precise excess volumes of mixing measurements at T = 313.15 K are reported over the whole composition range for binary mixtures: (N,N-dimethylacetamide + water), (N,N-dimethylacetamide + methanol), (N,N-dimethylacetamide + ethanol) and for the ternary mixtures (N,N-dimethylacetamide + methanol + water) and (N,N-dimethylacetamide + ethanol + water). For all the systems, large negative deviations from ideality are observed. The binary results have been fitted using the Redlich–Kister type polynomial. The possibility of predicting the ternary results from the binary ones was examined.     

Effect of ionic liquids on (vapor + liquid) equilibrium behavior of (water + 2-methyl-2-propanol)

Isobaric T, x, y data were reported for ternary systems of {water + 2-methyl-2-propanol (tert-butyl alcohol, TBA) + ionic liquid (IL)} at p = 100 kPa. When the mole fraction of TBA on IL-free basis was fixed at 0.95, measurements were performed at IL mass fractions from 0.6 down to 0.05, in a way of repeated synthesis. The vapor-phase compositions were obtained by analytical methods and the liquid-phase compositions were calculated with the aid of mass balances. Activity coefficients of water and TBA were obtained without the need of a thermodynamic model of the liquid-phase. Six ILs, composed of an anion chosen from [OAc]^? or [Cl]^?, and a cation from [emim]⁺, or [bmim]⁺, or [hmim]⁺, were studied. Relative volatility and activity coefficients were presented in relation with the IL mole fraction, showing the effect of the ILs on a molar basis. The effect of the ILs on relative volatility of TBA to water was depicted by the effect of anions and cations on, respectively, the activity coefficients of water and TBA. The results indicated that, among the six ILs studied, [emim][Cl] has the most significant effect on enhancement of the relative volatility, which reaches a value of 7.2 at an IL mass fraction of 0.58. Another IL, [emim][OAc], has also significant effect, with an appreciable value of 5.2 for the relative volatility when the IL mass fraction is 0.6. Considering the relatively low viscosity and melting point of [emim][OAc], it might be a favorable candidate as solvent for the separation of water and TBA by extractive distillation. Simultaneous correlation by the NRTL model was presented for both systems of (water + ethanol + IL) and (water + TBA + IL), using consistent binary parameters for water and IL.