About seller
Seasonal changes in temperature, humidity, and rainfall affect vector survival and emergence of mosquitoes and thus impact the dynamics of vector-borne disease outbreaks. Recent studies of deterministic and stochastic epidemic models with periodic environments have shown that the average basic reproduction number is not sufficient to predict an outbreak. We extend these studies to time-nonhomogeneous stochastic dengue models with demographic variability wherein the adult vectors emerge from the larval stage vary periodically. The combined effects of variability and periodicity provide a better understanding of the risk of dengue outbreaks. A multitype branching process approximation of the stochastic dengue model near the disease-free periodic solution is used to calculate the probability of a disease outbreak. The approximation follows from the solution of a system of differential equations derived from the backward Kolmogorov differential equation. This approximation shows that the risk of a disease outbreak is also periodic and depends on the particular time and the number of the initial infected individuals. Numerical examples are explored to demonstrate that the estimates of the probability of an outbreak from that of branching process approximations agree well with that of the continuous-time Markov chain. In addition, we propose a simple stochastic model to account for the effects of environmental variability on the emergence of adult vectors from the larval stage.The Colless index for bifurcating phylogenetic trees, introduced by Colless (1982), is defined as the sum, over all internal nodes v of the tree, of the absolute value of the difference of the sizes of the clades defined by the children of v. It is one of the most popular phylogenetic balance indices, because, in addition to measuring the balance of a tree in a very simple and intuitive way, it turns out to be one of the most powerful and discriminating phylogenetic shape indices. But it has some drawbacks. On the one hand, although its minimum value is reached at the so-called maximally balanced trees, it is almost always reached also at trees that are not maximally balanced. On the other hand, its definition as a sum of absolute values of differences makes it difficult to study analytically its distribution under probabilistic models of bifurcating phylogenetic trees. In this paper we show that if we replace in its definition the absolute values of the differences of clade sizes by the squares of these differences, all these drawbacks are overcome and the resulting index is still more powerful and discriminating than the original Colless index.In this study, a novel Vigna radiata based porous starch (PS) is prepared by solvent exchange technique and explored as a solubilizer for model drug albendazole (ABZ). PS carrier was investigated for different chemical, functional, and micromeritic properties. Solubilizing potential of PS is evaluated by formulating ABZ-PS solid dispersion (10.5-12) based tablets (SDT). ABZ-PS solid dispersions were evaluated for micromeritic properties, dissolution studies, and anthelmintic activity. Direct compression suitability and susceptibility of mung bean starch were studied by SeDem diagram, Heckel, and Kawakita analysis respectively. PS had an A-type crystallinity pattern and evinced functional properties similar to other legume starches. PS was determined to be suitable for direct compression (good compressibility index = 5.50). SD (12) manifested 36.18 fold and 1.6-3.04 fold improvement in the % dissolution and anthelmintic activity of ABZ respectively. All SD batches (R2 = 0.949-0.996) and ABZ (R2 = 0.168) followed the Higuchi-matrix release kinetic model. DSC and P-XRD analysis corroborated the amorphous form of ABZ. SDT showed ≈ a 1.90 fold improvement in dissolution rate than the marketed formulation. Conclusively, Vigna radiata PS could be explored as an alternative to reduce the large burden on the established starches.Metalloporphyrins (FeTBAP, MnTBAP, FeTMPyP and MnTMPyP) have been proposed as effective therapeutic agents in ONOO--related disease including type 2 diabetes (T2D). As these metalloporphyrins share the structural similarities of the planar aromatic conjugation with a valuable class of inhibitors against amyloids fibrillation, they might be effective inhibitors via aromatic π-π stacking interactions with amyloid peptides. find more Here, we found that the anionic metalloporphyrins (FeTBAP and MnTBAP) are effective inhibitors against hIAPP fibrillation, while, the cationic metalloporphyrins (FeTMPyP and MnTMPyP) only have limited inhibitory effects. Besides, the porphyrin with iron center is more effective than the one with manganese center. Our results favor the electrostatic attraction contributes the main reason to the inhibitory effect between the anionic porphyrins and hIAPP, followed by the π-π stacking interactions between aromatic ring of porphyrins and hIAPP and the stronger coordination ability of iron center to hIAPP. Additionally, by comparison with FeTBAP, which can completely inhibit cytotoxicity induced by hIAPP via stabilizing hIAPP monomers, MnTBAP fails to reverse the cytotoxicity due to that it can only delay the transition of hIAPP from α-helix to β-sheet rich oligomers. Our results provide theoretical significance for further designing or screening of metalloporphyrins as bifunctional antidiabetic drugs.Flower-like metal-organic frameworks (Cu-MOF) nanoparticles are successfully synthesized and incorporated into cellulose acetate (CA) matrix to prepare CA-based functional nanocomposite films via a simple solution-casting method. The effect of the incorporation of flower-like Cu-MOF on the morphological, mechanical, thermal, surface wettability, water vapor barrier, cytotoxicity, photostability and UV-shielding properties of CA films is fully investigated. Results reveal that the flower-like Cu-MOF has good compatibility with CA, providing uniform and compact nanocomposite films. The as-prepared nanocomposite films show improved mechanical properties, surface hydrophobicity, water vapor barrier ability compared to neat CA film, and exhibit super UV-shielding capability through the entire UV regions meanwhile retaining a high visible transparency. Moreover, the high transparency and UV-shielding ability of the nanocomposite films can be still maintained even after continuous UV-light (365 nm) irradiation for 12 h.