Inhibition effect of phenyl compounds from the Oryza sativa roots on melanin production in murine B16-F10 melanoma cells

Five phenyl compounds, vanillin (1), methyl trans-ferulate (2), trans-p-coumaric acid methyl ester (3), N-benzoyltryptamine (4), and N-(trans-cinnamoyl)tryptamine (5), were isolated from the roots of Oryza sativa L. and identified on the basis of spectroscopic data. Compounds 3 and 5 showed strong inhibition effect on melanin production in murine B16-F10 melanoma cells and tyrosinase activity. Also, the quantitative analysis of the compounds was carried out using LC/MS/MS experiment. Compounds 3 and 5 could be used as skin-whitening agents.     

A review of new wire arrays with open and closed magnetic configurations at the 1.6 MA Zebra generator for radiative properties and opacity effects

The studies emphasize investigation of plasma formation, implosion, and radiation features as a function of two load configurations: compact multi-planar and cylindrical wire arrays. Experiments with different Z-pinch loads were performed on 1.6 MA, 100 ns, Zebra generator at University of Nevada, Reno. The multi-planar wire arrays (PWAs) were studied in open and closed configurations with Al, Cu, brass, Mo and W wires. In the open magnetic configurations (single, double, triple PWAs) magnetic fields are present inside the arrays from the beginning of discharge, while in closed configurations (prism-like PWA) the global magnetic field is excluded inside before plasma flow occurs. The new prism-like PWA allows high flexibility in control of implosion dynamics and precursor formation. The spectral modeling, magneto-hydrodynamic (MHD) and wire ablation dynamic model (WADM) codes were used to describe the plasma evolution and plasma parameters. Experimentally observed electron temperature and density in multiple bright spots reached 1.4 keV and 5 × 10²¹ cm^?3, respectively. Two types of bright spots were observed. With peak currents up to 1.3 MA opacity effects became more pronounced and led to a limiting of the X-ray yields from compact cylindrical arrays. Despite different magnetic energy to plasma coupling mechanisms early in the implosion a comparison of compact double PWA and cylindrical WA results indicates that during the stagnation stage the same plasma heating mechanism may occur. The double PWA was found to be the best radiator tested at University scale 1 MA generator. It is characterized by a combination of larger yield and power, mm-scale size, and provides the possibility of radiation pulse shaping. Further, the newer configuration, the double PWA with skewed wires, was tested and showed the possibility of a more effective X-ray generation.     

Time-gated measurements of electron beam generated Kα emission lines from brass planar wire array implosions

The relative amount of Kα radiation emitted by partially ionized copper and zinc from planar wire arrays on the 1 MA Zebra generator at the University of Nevada, Reno, does not correspond to the composition (70% copper, 30% zinc) of the array's brass wires. For example, the copper Kα line at 8 keV was observed to be much stronger than would be expected from zinc's Kα radiation at 8.6 keV, but this ratio also reversed, more emission from zinc than from copper, during the X-ray pulse. An excess of Kα photons from copper is consistent with a beam of electrons with energies above copper's K-edge but below that of zinc, but the opposite case is perplexing. Preferential ablation of Zn over Cu early in the current pulse could be a contributing factor, but opacity effects are not. Synthetic spectra for brass computed by a non-LTE collisional-radiative model that includes an electron beam component compare well with observed K-shell spectra, and suggest the parent ions of the Kα emission. These ionization stages are consistent with L-shell spectra. This comparison also indicates that the total energy in the electron beam increases towards the end of the radiation pulse while the electron temperature decreases. The crucial diagnostic in this measurement is a time-resolved X-ray spectrometer based on a LiF crystal.     

Unknown biological mixtures evaluation using STR analytical quantification

Allelic quantification of STRs, where the presence of three or more alleles represents mixtures, provides a novel method to identify mixtures from unknown biological sources. The allelic stutters resulting in slightly different repeat containing products during fragment amplification can be mistaken for true alleles complicating a simple approach to mixture analysis. An algorithm based on the array of estimated stutters from known samples was developed and tuned to maximize the identification of true non-mixtures through the analysis of three pentanucleotide STRs. Laboratory simulated scenarios of needle sharing generated 58 mixture and 38 non-mixture samples that were blinded for determining the number of alleles. Through developing and applying an algorithm that additively estimates stuttering around the two highest peaks, mixtures and non-mixtures were characterized with sensitivity of 77.5, 82.7 and 58% while maintaining the high specificity of 100, 97.4 and 100 for the W, X, and Z STRs individually. When all three STRs were used collectively, the resulting sensitivity and specificity was 91.4 and 97.4%, respectively. The newly validated approach of using multiple STRs as highly informative biomarkers in unknown sample mixture analyses has potential applications in genetics, forensic science, and epidemiological studies.     

Anthozoa red fluorescent protein in biosensing

The identification and cloning of a red fluorescent protein (DsRed) obtained from Anthozoa corals has provided an alternative to commonly used green fluorescent proteins (GFPs) in bioanalytical and biomedical research. DsRed in tandem with GFPs has enhanced the feasibility of multicolor labeling studies. Properties of DsRed, for example high photostability, red-shifted fluorescence emission, and stability to pH changes have proven valuable in its use as a fluorescent tag in cell-biology applications. DsRed has some limitations, however. Its slow folding and tendency to form tetramers have been a hurdle. Several different mutational studies have been performed on DsRed to overcome these problems. In this paper, applications of DsRed in biosensing, specifically in FRET/BRET assays, whole-cell assays, and in biosensors, is discussed. In the future, construction of DsRed mutants with unique characteristics will further expand its applications in bioanalysis.     

Fluctuating flow of an elastico-viscous fluid along an infinite porous plate with an applied magnetic field

The problem of oscillating free stream flow of an elastico-viscous, incompressible, and electrically conducting fluid along an infinite plate with suction varying periodically with time, is considered in the presence of a transverse magnetic field. The effect of the elasticity of the fluid, the magnetic fluid, and the fluctuation of suction velocity on the velocity and the skin friction is examined.     

Single‐Molecule Mechanochemical Sensing Using DNA Origami Nanostructures

While single‐molecule sensing offers the ultimate detection limit, its throughput is often restricted as sensing events are carried out one at a time in most cases. 2D and 3D DNA origami nanostructures are used as expanded single‐molecule platforms in a new mechanochemical sensing strategy. As a proof of concept, six sensing probes are incorporated in a 7‐tile DNA origami nanoassembly, wherein binding of a target molecule to any of these probes leads to mechanochemical rearrangement of the origami nanostructure, which is monitored in real time by optical tweezers. Using these platforms, 10 pM platelet‐derived growth factor (PDGF) are detected within 10 minutes, while demonstrating multiplex sensing of the PDGF and a target DNA in the same solution. By tapping into the rapid development of versatile DNA origami nanostructures, this mechanochemical platform is anticipated to offer a long sought solution for single‐molecule sensing with improved throughput.     

Self-Assembled Structures of Diglycerol Monolaurate- and Monomyristate in Olive Oil

We have investigated the phase behavior and self-assembled structures of diglycerol monolaurate-and monomyristate (abbreviated as C₁₂G₂ and C₁₄G₂, respectivley) in olive oil over a wide range of temperatures and compositions. At lower temperatures, both the surfactants appear in solid state (α-solid), which does not swell with olive oil. The α-solid transforms into lamellar liquid crystal (L_α) phase upon heating and the solid melting temperature is practically constant at all surfactant/oil compositions, but the C₁₂G₂ melts earlier than the C₁₄G₂. There appear the dispersions of L_α phase and α-solid in the dilute regions of the C₁₂G₂/olive oil and the C₁₄G₂/olive oil systems, respectively, at 25°C. The L_α phase can solubilize some amount of olive oil, but as the oil concentration increases the excess oil separates out from the L_α phase, and there appears L_α dispersion in the dilute surfactant concentration region. The L_α phase eventually transforms into isotropic solutions (reverse micelles) with further heating. The structures (shape and size) of the reverse micelles have been characterized by small-angle x-ray scattering technique. It has found that the C₁₂G₂ and C₁₄G₂ surfactants form reverse rod-like micelles in olive oil above the L_α melting temperature and the micellar size increases with surfactant concentration, but decreases with temperatures.