Determinations of upper critical field in continuous Ginzburg-Landau model

Novel procedures to determine the upper critical field $B_{c2}$ have been proposed within a continuous Ginzburg-Landau model. Unlike conventional methods, where $B_{c2}$ is obtained through the determination of the smallest eigenvalue of an appropriate eigen equation, the square of the magnetic field is treated as eigenvalue problems so that the upper critical field can be directly deduced. The calculated $B_{c2}$ from the two procedures are consistent with each other and in reasonably good agreement with existing theories and experiments. The profile of the order parameter associated with $B_{c2}$ is found to be Gaussian-like, further validating the methodology proposed. The convergences of the two procedures are also studied.Comment: Revtex4, 8 pages, 4 figures, references modified, figures and table embedde

Anomalous thermopower and Nernst effect in CeCoIn5\rm CeCoIn_5: entropy-current loss in precursor state

The heavy-electron superconductor CeCoIn$_5$ exhibits a puzzling precursor state above its superconducting critical temperature at $T_c$ = 2.3 K. The thermopower and Nernst signal are anomalous. Below 15 K, the entropy current of the electrons undergoes a steep decrease reaching $\sim$0 at $T_c$. Concurrently, the off-diagonal thermoelectric current $\alpha_{xy}$ is enhanced. The delicate sensitivity of the zero-entropy state to field implies phase coherence over large distances. The prominent anomalies in the thermoelectric current contrast with the relatively weak effects in the resistivity and magnetization.Comment: 5 figures, 4 page

Molten Salt Thermal Energy Storage Systems

The feasibility of storing thermal energy at temperatures of 450 C to 535 C in the form of latent heat of fusion was examined for over 30 inorganic salts and salt mixtures. Alkali carbonate mixtures were chosen as phase-change storage materials in this temperature range because of their relatively high storage capacity and thermal conductivity, moderate cost, low volumetric expansion upon melting, low corrosivity, and good chemical stability. Means of improving heat conduction through the solid salt were explored

Proteomic Analysis of Bacterial Expression Profiles Following Exposure to Organic Solvent Flower Extract of Melastoma candidum D Don (Melastomataceae)

Purpose: To identify potential antibacterial protein targets following exposure to Melastoma candidum extract.Methods: Plant extracts were prepared using sequential extraction method. Denaturing gel electrophoresis and MALDI TOF-TOF MS protein sequencing were used to identify differentialexpressed bacterial proteins. 96-well microplate method was used to determine the minimum inhibitory concentration (MIC) values. Thin layer chromatography (TLC) bio-autobiography and gaschromatography-mass spectrometry (GC-MS) were performed to determine the phytochemicals in the active fraction.Results: Five differentially expressed bacterial proteins (four from Escherichia coli and one from Staphylococcus aureus), were identified via proteomic approach. Among the bacterial proteins identified, glutamate decarboxylase, elongation factor-Tu and α-hemolysin are especially noteworthy, as they are implicated in critical bacterial pathways pertaining to survival in acidic environment, protein translation and virulence, respectively. Additionally, we tested and reported the minimum inhibition concentrations of different M. candidum fractions and gas chromatography-mass spectrometry GC-MS analysis of the active fraction.Conclusion: Glutamate decarboxylase, elongation factor-Tu and α-hemolysin represent potential antibacterial targets.Keywords: Escherichia coli, Staphylococcus aureus, Melastoma candidum, Glutamate decarboxylase, Elongation factor-Tu, α-Hemolysin, Protein expressio

Extraction of VubV_{ub} from the Decay B→πlνB\to \pi l \nu

We develop the perturbative QCD formalism including Sudakov effects for semi-leptonic $B$ meson decays. We evaluate the differential decay rate of $B\to \pi l \nu$, and find that the perturbative calculation is reliable for the energy fraction of the pion above 0.3. Combining predictions from the soft pion theorems, we extract the value of the matrix element $|V_{ub}|$ which is roughly $2.7\times 10^{-3}$.Comment: 10 pages, CCUTH-94-05, IP-ASTP-13-9

Evaluation of Glucosidase Inhibitory and Cytotoxic Potential of Five Selected Edible and Medicinal Ferns

Purpose: To evaluate the glucosidase inhibitory and cytotoxic activities of five selected edible and medicinal ferns, namely, Blechnum orientale, Davallia denticulata, Diplazium esculentum, Nephrolepis biserrata, and Pteris vittata.Methods: The aqueous extracts of the five ferns were prepared by water extraction at 90 ºC for 1 h. Antiglucosidase assay was used to determine the effect of each extract on yeast alpha-glucosidase activity in vitro. Cytotoxicity was evaluated using methylthiazol tetrazolium assay on chronic myelogenous leukaemia cell line (K562). The phenolic, hydroxycinnamic acid, flavonoid and proanthocyanidin contents of the extracts were also determined.Results: The α-glucosidase inhibitory activity of D. esculentum (half maximal effective concentration, EC50 = 6.85 μg/ml) was considerably stronger than that of myricetin (EC50 = 53.21 μg/ml). B. orientale, D. esculentum, N. biserrata, and P. vittata were cytotoxic to K562 cells. P. vittata had the strongest cytotoxicity, although it was less potent than 5-fluorouracil. D. denticulata had the highest phenolic, hydroxycinnamic acid and flavonoid contents of all the extracts while B. orientale had the highest proanthocyanidin content.Conclusion: Among the five ferns evaluated, D. esculentum is a potential source of an antidiabetic agent and is recommended for further investigation in this regard. All the fern extracts, except D. denticulata, exhibited dose-dependent cytotoxicity against K562 cells.Keywords: Medicinal fern, α-Glucosidase inhibition, Cytotoxicity, Blechnum orientale, Davallia denticulata, Diplazium esculentum, Nephrolepis biserrata, Pteris vittat