Determination of flow activation energy at viscosity maximum for spherical and wormlike micelles of different lengths and flexibility

Steady shear rheological measurements were carried out on aqueous solutions containing 15 mM cetyltrimethylammonium bromide (CTABr) and a constant value of [MX] and temperature for MX = 2,3-; 2,4-; 2,5-; 2,6-; 3,4-; and 3,5-Cl₂BzNa with Bz^?representing C₆H₃CO_2?. Plots of zero shear viscosity (η ₀) vs. [MX] at 35 °C and 15 mM CTABr show the presence of single maximum and double maxima for MX = 2,3- and 3,5-Cl₂BzNa, respectively. Turbidity data (absorbance at 600 nm vs. [MX]) coupled with η ₀vs. [MX] data at 35 °C reveal indirectly the presence of vesicles along with wormlike micelles (WM) at MX / CTABr > 0. 7 for MX = 3,5-Cl₂BzNa. Temperature dependence of η ₀in the vicinity of the viscosity maximum shows nonlinear and linear Arrhenius behavior, within the temperature range of 20–55 °C, for MX = 2,3-; 2,4-; 2,5-; 3,4-; and 3,5-Cl₂BzNa, respectively. The values of η ₀, $\dot {\gamma }_{\text {cr}} $ (critical shear rate), and flow activation energy correlate with CTABr micellar binding constants of counterions.     

Induction of Apoptosis and Regulation of MicroRNA Expression by (2E,6E)-2,6-bis-(4-hydroxy-3-methoxybenzylidene)-cyclohexanone (BHMC) Treatment on MCF-7 Breast Cancer Cells

(2E,6E)-2,6-bis-(4-hydroxy-3-methoxybenzylidene)-cyclohexanone (BHMC) is a synthetic curcumin analogue, which has been reported to possess anti-tumor, anti-metastatic, and anti-invasion properties on estrogen receptor (ER) negative breast cancer cells in vitro and in vivo. However, the cytotoxic effects of BHMC on ER positive breast cancer cells were not widely reported. This study was aimed to investigate the cytotoxic potential of BHMC on MCF-7 cells using cell viability, cell cycle, and apoptotic assays. Besides, microarray and quantitative polymerase chain reaction (qPCR) were performed to identify the list of miRNAs and genes, which could be dysregulated following BHMC treatment. The current study discovered that BHMC exhibits selective cytotoxic effects on ER positive MCF-7 cells as compared to ER negative MDA-MB-231 cells and normal breast cells, MCF-10A. BHMC was shown to promote G2/M cell cycle arrest and apoptosis in MCF-7 cells. Microarray and qPCR analysis demonstrated that BHMC treatment would upregulate several miRNAs like miR-3195 and miR-30a-3p and downregulate miRNAs such as miR-6813-5p and miR-6132 in MCF-7 cells. Besides, BHMC administration was also found to downregulate few tumor-promoting genes like VEGF and SNAIL in MCF-7. In conclusion, BHMC induced apoptosis in the MCF-7 cells by altering the expressions of apoptotic-regulating miRNAs and associated genes.     

The Causality and Uncertainty of the COVID-19 Pandemic to Bursa Malaysia Financial Services Index’s Constituents

Valued in hundreds of billions of Malaysian ringgit, the Bursa Malaysia Financial Services Index’s constituents comprise several of the strongest performing financial constituents in Bursa Malaysia’s Main Market. Although these constituents persistently reside mostly within the large market capitalization (cap), the existence of the individual constituent’s causal influence or intensity relative to each other’s performance during uncertain or even certain times is unknown. Thus, the key purpose of this paper is to identify and analyze the individual constituent’s causal intensity, from early 2018 (pre-COVID-19) to the end of the year 2021 (post-COVID-19) using Granger causality and Schreiber transfer entropy. Furthermore, network science is used to measure and visualize the fluctuating causal degree of the source and the effected constituents. The results show that both the Granger causality and Schreiber transfer entropy networks detected patterns of increasing causality from pre- to post-COVID-19 but with differing causal intensities. Unexpectedly, both networks showed that the small- and mid-caps had high causal intensity during and after COVID-19. Using Bursa Malaysia’s sub-sector for further analysis, the Insurance sub-sector rapidly increased in causality as the year progressed, making it one of the index’s largest sources of causality. Even after removing large amounts of weak causal intensities, Schreiber transfer entropy was still able to detect higher amounts of causal sources from the Insurance sub-sector, whilst Granger causal sources declined rapidly post-COVID-19. The method of using directed temporal networks for the visualization of temporal causal sources is demonstrated to be a powerful approach that can aid in investment decision making.     

N‐(6‐Bromo‐4‐oxo‐3,4‐di­hydro­pteridin‐2‐yl)‐2,2‐di­methyl­propan­amide

In the title compound, C₁₁H₁₂BrN₅O₂, the rings in the pterin moiety are planar. The carbonyl O atom is in a synperiplanar conformation, while the C—N—C(=O)—C linkage is antiperiplanar. N—H?N and N—H?O intermolecular hydrogen bonds transform the mol­ecules into infinite chains.