In Vitro Alpha-Amylase and Alpha-Glucosidase Inhibitory Activity and In Vivo Antidiabetic Activity of Withania frutescens L. Foliar Extract

Withania frutescens L. is a wild perennial woody plant used by the local population for diverse therapeutic purposes. This work aims to study for the first time the potential inhibitory effect of this plant hydroethanolic extract on α-amylase and α-glucosidase activities using in vitro methods and its antidiabetic and antihyperglycemic activities using alloxan-induced diabetic mice as a model for experimental diabetes. Two doses were selected for the in vivo study (200 and 400 mg/kg) and glibenclamide, a well-known antidiabetic drug (positive control) in a subacute study (28 days) where the antihyperglycemic activity was also assessed over a period of 12 h on diabetic mice. The continuous treatment of diabetic mice with the extract of Withania frutescens for 4 weeks succeeded to slowly manage their high fasting blood glucose levels (after two weeks), while the antihyperglycemic test result revealed that the extract of this plant did not control hyperglycemia in the short term. No toxicity signs or death were noted for the groups treated with the plant extract, and it shows a protective effect on the liver and kidney. The in vitro assays demonstrated that the inhibition of alpha-amylase and alpha-glucosidase might be one of the mechanisms of action exhibited by the extract of this plant to control and prevent postprandial hyperglycemia. This work indicates that W. frutescens have an important long term antidiabetic effect that can be well established to treat diabetes.     

Fractional proportional differences with memory

In this paper, we formulate nabla fractional sums and differences and the discrete Laplace transform on the time scale h?. Based on a local type h-proportional difference (without memory), we generate new types of fractional sums and differences with memory in two parameters which are generalizations to the formulated fractional sums and differences. The kernel of the newly defined generalized fractional sum and difference operators contain h-discrete exponential functions. The discrete h-Laplace transform and its convolution theorem are then used to study the newly introduced discrete fractional operators and also used to solve Cauchy linear fractional difference type problems with step 0 < h ≤ 1.     

Janerin Induces Cell Cycle Arrest at the G2/M Phase and Promotes Apoptosis Involving the MAPK Pathway in THP-1, Leukemic Cell Line

Janerin is a cytotoxic sesquiterpene lactone that has been isolated and characterized from different species of the Centaurea genus. In this study, janerin was isolated form Centaurothamnus maximus, and its cytotoxic molecular mechanism was studied in THP-1 human leukemic cells. Janerin inhibited the proliferation of THP-1 cells in a dose-dependent manner. Janerin caused the cell cycle arrest at the G2/M phase by decreasing the CDK1/Cyclin-B complex. Subsequently, we found that janerin promoted THP-1 cell death through apoptosis as indicated by flow cytometry. Moreover, apoptosis induction was confirmed by the upregulation of Bax, cleaved PARP-1, and cleaved caspase 3 and the downregulation of an anti-apoptotic Bcl-2 biomarker. In addition, immunoblotting indicated a dose dependent upregulation of P38-MAPK and ERK1/2 phosphorylation during janerin treatment. In conclusion, we have demonstrated for the first time that janerin may be capable of inducing cell cycle arrest and apoptosis through the MAPK pathway, which would be one of the mechanisms underlying its anticancer activity. As a result, janerin has the potential to be used as a therapeutic agent for leukemia.     

Hydrogen adsorption in the metal-organic frameworks Fe2(dobdc) and Fe2(O2)(dobdc)

The hydrogen storage properties of Fe(2)(dobdc) (dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate) and an oxidized analog, Fe(2)(O(2))(dobdc), have been examined using several complementary techniques, including low-pressure gas adsorption, neutron powder diffraction, and inelastic neutron scattering. These two metal-organic frameworks, which possess one-dimensional hexagonal channels decorated with unsaturated iron coordination sites, exhibit high initial isosteric heats of adsorption of -9.7(1) and -10.0(1) kJ mol(-1), respectively. Neutron powder diffraction has allowed the identification of three D(2) binding sites within the two frameworks, with the closest contacts corresponding to Fe-D(2) separations of 2.47(3) and 2.53(5) ?, respectively. Inelastic neutron scattering spectra, obtained from p-H(2) (para-H(2)) and D(2)-p-H(2) mixtures adsorbed in Fe(2)(dobdc), reveal weak interactions between two neighboring adsorption sites, a finding that is in opposition to a previous report of possible 'pairing' between neighboring H(2) molecules.     

CO(2) Dynamics in a Metal-Organic Framework with Open Metal Sites

Metal-organic frameworks (MOFs) with open metal sites are promising candidates for CO(2) capture from dry flue gas. We applied in situ(13)C NMR spectroscopy to investigate CO(2) adsorbed in Mg(2)(dobdc) (H(4)dobdc = 2,5-dihydroxyterephthalic acid; Mg-MOF-74, CPO-27-Mg), a key MOF in which exposed Mg(2+) cation sites give rise to exceptional CO(2) capture properties. Analysis of the resulting spectra reveals details of the binding and CO(2) rotational motion within the material. The dynamics of the motional processes are evaluated via analysis of the NMR line shapes and relaxation times observed between 12 and 400 K. These results form stringent and quantifiable metrics for computer simulations that seek to screen and improve the design of new MOFs for CO(2) capture.     

Role of the anion in the underpotential deposition of cadmium on a Rh(111) electrode: probed by voltammetry and in situ scanning tunneling microscopy

In situ scanning tunneling microscopy (STM) and cyclic voltammetry (CV) were employed to examine the underpotential deposition (UPD) of cadmium on a rhodium(111) electrode in sulfuric and hydrochloric acids. The (bi)sulfate and chloride anions in the electrolytes played a main role in controlling the number and arrangement of Cd adatoms. Deposition of Cd along with hydrogen adsorption occurred near 0.1 V (vs reversible hydrogen electrode) in either 0.05 M H2SO4 or 0.1 M HCl containing 1 mM Cd(ClO4)2. These coupled processes resulted in an erroneous coverage of Cd adatoms. The process of Cd deposition shifted positively to 0.3 V and thus separated from that of hydrogen in 0.05 M H2SO4 containing 0.5 M Cd2+. The amount of charge (80 microC/cm2) for Cd deposition in 0.5 M Cd2+ implied a coverage of 0.17 for the Cd adatoms, which agreed with in situ STM results. Regardless of [Cd2+], in situ STM imaging revealed a highly ordered Rh(111)-(6 x 6)-6Cd + HSO4- or SO42- structure in sulfuric acid,. In hydrochloric acid, in situ STM discerned a (2 x 2)-Cd + Cl structure at potentials where Cd deposition commenced. STM atomic resolution showed roughly one-quarter of a monolayer of Cd adatoms were deposited, ca. 50% more than in sulfuric acid. Dynamic in situ STM imaging showed potential dependent, reversible transformations between the (6 x 6) Cd adlattices and (square root 3 x square root 7)-(bi)sulfate structure, and between (2 x 2) and (square root 7 x square root 7)R19.1 degrees -Cl structures. The fact that different Cd structures observed in H2SO4 and HCl entailed the involvement of anions in Cd deposition, i.e. (bi)sulfate and chloride anions were codeposited with Cd adatoms on Rh(111).     

On the existence and the uniqueness theorem for fractional differential equations with bounded delay within Caputo derivatives

Local and global existence and uniqueness theorems for a functional delay fractional differential equation with bounded delay are investigated. The continuity with respect to the initial function is proved under Lipschitz and the continuity kind conditions are analyzed.     

Generalized fractional derivatives generated by a class of local proportional derivatives

Recently, Anderson and Ulness [Adv. Dyn. Syst. Appl. 10, 109 (2015)] utilized the concept of the proportional derivative controller to modify the conformable derivatives. In parallel to Anderson’s work, Caputo and Fabrizio [Progr. Fract. Differ. Appl. 1, 73 (2015)] introduced a fractional derivative with exponential kernel whose corresponding fractional integral does not have a semi-group property. Inspired by the above works and based on a special case of the proportional-derivative, we generate Caputo and Riemann-Liouville generalized proportional fractional derivatives involving exponential functions in their kernels. The advantage of the newly defined derivatives which makes them distinctive is that their corresponding proportional fractional integrals possess a semi-group property and they provide undeviating generalization to the existing Caputo and Riemann-Liouville fractional derivatives and integrals. The Laplace transform of the generalized proportional fractional derivatives and integrals are calculated and used to solve Cauchy linear fractional type problems.