Volumetric and Viscometric Studies of Amino Acids in Vitamin B6 Aqueous Solutions at Various Temperatures

The densities and viscosities of glycine, l-alanine, l-valine, l-threonine, and l-arginine in (0.1 to 0.4) mol·kg^–1 vitamin B6 aqueous solutions were measured and studied over the entire molality range at (293.15, 303.15, 313.15, and 323.15) K and atmospheric pressure. The apparent molar volume (<i>V</i>_ϕ), limiting partial molar volume (<i>V</i>_ϕ⁰), and limiting partial molar volume of transfer (Δ_tr<i>V</i>_ϕ⁰) were obtained according to the experimental density data. The viscosity data were employed to determine the viscosity <i>B</i> coefficients, the free energies of activation per mole of solvent (Δμ₁^0⇌) and solute (Δμ₂^0⇌). The influences of temperature, molality, and solute structure on these parameters were discussed in terms of molecular interactions. The contributions of the charged end group (NH₃⁺, COO^–) and CH₂ group to the limiting partial molar volumes and viscosity <i>B</i> coefficients were obtained through their linear correlation as a function of the number of carbon atoms in the alkyl chains of the studied amino acids

Nano-fumed silica as a novel pollutant that inhibits the algicidal effect of <i>p</i>-hydroxybenzoic acid on <i>Microcystis aeruginosa</i>

<p>Nanomaterials and/or contaminants are becoming more common in the developing world, but their effects on interspecific interactions are rarely reported, particularly in aquatic ecosystems. Thus, the present study determined the effects of the novel pollutant nano-fumed silica (NFS) on algal control by a macrophyte via the allelochemical <i>p</i>-hydroxybenzoic acid in a microcosm test. The allelochemical <i>p-</i>hydroxybenzoic acid caused significant decreases in chlorophyll <i>a</i>, but increased the amount of superoxide anion radicals (<math><msubsup>O<mn>2</mn><mrow><mo>∙</mo><mo>−</mo></mrow></msubsup></math>) and the electric conductivity in <i>Microcystis aeruginosa</i>. The 50% inhibitory concentration (IC₅₀) for <i>p</i>-hydroxybenzoic acid was 0.919 mmol/L in microalga during the exponential phase. Interestingly, NFS at 100–1600 mg/L had clear stimulatory effects on <i>M. aeruginosa</i>. When NFS at 800 mg/L was combined with different concentrations of <i>p</i>-hydroxybenzoic acid, the IC₅₀ for <i>p</i>-hydroxybenzoic acid was 1.045 mmol/L. Thus, NFS significantly reduced the algicidal effect exhibited by <i>p</i>-hydroxybenzoic acid on <i>M. aeruginosa.</i> Furthermore, NFS might act as a silicon nutrient and enhance allelopathic resistance in <i>M. aeruginosa</i> to inhibit the algicidal effects of macrophytes via allelopathy. These findings suggest that before algal control is considered using macrophyte allelopathy, it is essential to remove the pollutant NFS from polluted lakes.</p

Volumetric and Viscometric Studies of Amino Acids in Vitamin B6 Aqueous Solutions at Various Temperatures

The densities and viscosities of glycine, l-alanine, l-valine, l-threonine, and l-arginine in (0.1 to 0.4) mol·kg^–1 vitamin B6 aqueous solutions were measured and studied over the entire molality range at (293.15, 303.15, 313.15, and 323.15) K and atmospheric pressure. The apparent molar volume (<i>V</i>_ϕ), limiting partial molar volume (<i>V</i>_ϕ⁰), and limiting partial molar volume of transfer (Δ_tr<i>V</i>_ϕ⁰) were obtained according to the experimental density data. The viscosity data were employed to determine the viscosity <i>B</i> coefficients, the free energies of activation per mole of solvent (Δμ₁^0⇌) and solute (Δμ₂^0⇌). The influences of temperature, molality, and solute structure on these parameters were discussed in terms of molecular interactions. The contributions of the charged end group (NH₃⁺, COO^–) and CH₂ group to the limiting partial molar volumes and viscosity <i>B</i> coefficients were obtained through their linear correlation as a function of the number of carbon atoms in the alkyl chains of the studied amino acids

The statistical result of two sample t-test between the MCAO and healthy controls.

<p>Cluster number: the number of clusters with consecutive voxels with a significant decrease in FDG signal, which is assigned sequentially and artificially. The second line of Cluster 1 which contains large number of contiguous voxels refers to the other significant point in this Cluster.</p><p>K_E: the size of a cluster, in which the number such as 2992 stands for the voxel numbers in the cluster;</p><p>P_{FWE_corr}: the maximum confidence level in each cluster;</p><p>Max_T: the maximum t-value in each cluster;</p><p>Max_Z: the maximum Z-value in each cluster;</p><p>Peak coordinates (mm): the coordinates of the maximum point in Paxinos & Watson space;</p><p>x: the x-axis, which is negative to the left from the midline and positive to the right;</p><p>y: the y-axis, which is positive to the ventral direction relative to the dorsal;</p><p>z: the z-axis, which is positive to the olfactory bulb direction relative to the bregma and negative to the cerebellum direction.</p><p>The statistical result of two sample t-test between the MCAO and healthy controls.</p

The constructed synthetic FDG-PET images from atlas images in Paxinos & Watson space.

<p>It was shown in pseudo-color scaled and the color-bar stands for the intensity of each voxel in synthetic FDG-PET image. The six main anatomy structures were labeled, in which (1) stands for the olfactory bulb, (2) stands for the cortex, (3) stands for the hippocampi, (4) stands for the mesencephalon, (5) stands for the thalamus and (6) stands for the cerebellar.</p

Volumetric and spatial correspondence measures between three manually traced out and automatically extracted intracranial tissues, of which the result is shown as ‘the mean value ± standard deviation’.

<p>JS (%): Jaccard similarity (the optimal value is 100%);</p><p>RV (%): The relative error on volume (the optimal value is 0%);</p><p>FP (%): The proportions of false-positive (the optimal value is 0%);</p><p>FN (%): The proportions of false-negative (the optimal value is 0%).</p><p>Volumetric and spatial correspondence measures between three manually traced out and automatically extracted intracranial tissues, of which the result is shown as ‘the mean value ± standard deviation’.</p

Volumetric and spatial correspondence measures between manually traced out intracranial tissues from three experts, of which the result is shown as ‘the mean value ± standard deviation’.

<p>JS (%): Jaccard similarity (the optimal value is 100%);</p><p>RV (%): The relative error on volume (the optimal value is 0%);</p><p>FP (%): The proportions of false-positive (the optimal value is 0%);</p><p>FN (%): The proportions of false-negative (the optimal value is 0%).</p><p>Volumetric and spatial correspondence measures between manually traced out intracranial tissues from three experts, of which the result is shown as ‘the mean value ± standard deviation’.</p

The constructed rat brain template.

<p>(A) Axial, sagittal and coronal views of the standard FDG-PET template with extracranial tissues in Paxinos space; (B) axial, sagittal and coronal views of the corresponding FDG-PET canonical brain; and (C) axial, sagittal and coronal views of the corresponding intracranial mask image in Paxinos space. The cross point of red lines represent the origin point D3V. The origin point was the same in the images of template, canonical brain and intracranial mask.</p

Superimposing the co-registered FDG-PET canonical brain on the MRI T2WI structural canonical brain in Paxinos & Watson space.

<p>The co-registered FDG-PET canonical brain is presented with translucency and pseudo-color scaled. The MRI T2WI canonical brain is presented in gray-scale as a background. The color-bar stands for the intensity of each voxel in FDG-PET canonical brain, which is not translucent.</p

The result of two-sample t-test between the MCAO and healthy controls.

<p>(A) The projection of all the blobs were shown in a figure of rat brain, in which the red vees point to the global maximal t-value. (B) The display of the statistical result overlaid on axial, sagittal and coronal views of a structural single brain in Paxinos & Watson space, which is the three-dimensional illustration of one blob. And the color bar stands for the t-value of each significant voxel in Paxinos & Watson space.</p