Gene-Z: a device for point of care genetic testing using a smartphone

By 2012, point of care (POC) testing will constitute roughly one third of the $59 billion in vitro diagnostics market. The ability to carry out multiplexed genetic testing and wireless connectivity are emerging as key attributes of future POC devices. In this study, an inexpensive, user-friendly and compact device (termed Gene-Z) is presented for rapid quantitative detection of multiple genetic markers with high sensitivity and specificity. Using a disposable valve-less polymer microfluidic chip containing four arrays of 15 reaction wells each with dehydrated primers for isothermal amplification, the Gene-Z enables simultaneous analysis of four samples, each for multiple genetic markers in parallel, requiring only a single pipetting step per sample for dispensing. To drastically reduce the cost and size of the real-time detector necessary for quantification, loop-mediated isothermal amplification (LAMP) was performed with a high concentration of SYTO-81, a non-inhibiting fluorescent DNA binding dye. The Gene-Z is operated using an iPod Touch, which also receives data and carries out automated analysis and reporting via a WiFi interface. This study presents data pertaining to performance of the device including sensitivity and reproducibility using genomic DNA from Escherichia coli and Staphylococcus aureus. Overall, the Gene-Z represents a significant step toward truly inexpensive and compact tools for POC genetic testing.     

Synthesis of highly N-substituted indole library via conjugate additions of indoline and their synthetic tool potentials

A comprehensive library of N- or 1-substituted indoles was formed by conjugate additions of indoline with Michael acceptors followed by an oxidation step. Using N-substituted indoles as key Michael donors, the synthesis of 1,3-disubstituted indoles was also accomplished.     

Thickness Effect on Kβ/Kα Intensity Ratios in Barium,Lanthanum, Samarium,Gadolinium, Dysprosium,and Holmium

INTRODUCTION

Knowing the K_β/K_α intensity ratio is of great practical importance in the analysis of X-ray spectra. The information is needed in the experimental investigations of various phenomena in the fields of atomic, nuclear and radiation physics and non-destructive testing of materials and elemental analysis using X-ray fluorescence techniques. K_α, X-ray arise from transition from the L shell to K shell and K_β, X-ray arise from transition from the M, N, 0 shells to K shell.     

Anisotropy of L X-rays of Uranium and Thorium

INTRODUCTION

The theoretical calculations by Flugge et a1 [l] have shown that the Xrays originating from the states corresponding to J=1/2(K shell and L_I, L_II, M_I, M_II subshell etc.) are emitted to be isotropic and those corresponding to state J=5/2(e.g. Mv subshell) are emitted to be anisotropic in their spatial distribution. There are many studies on L X-ray intensity ratios. But there is little reported on isotropy and anisotropy of L X-rays. Kahlon et a1 [2,3] investigated isotropy and anisotropy of L X-rays. We investigated the anisotropy of L shell X-rays in Au and Hg [4] and the angular dependence of differential cross-sections of L X-rays from Hg, T1 and Pb [5].     

Hexagonal-surface-webs formed by n-pencils of spheres belonging to the same bundle

In this work,it is shown that n pencils of spheres which belong to the same bundle form a hexagonal-surface-web.Firstly,4 pencils of spheres orthogonal to the same sphere are taken into consideration. Later,by means of a suitable transformation,the equations of these 4 pencils of spheres are written in their simplest form and the equation of the surface web is obtained.Then,it is concluded that any 4- pencils of spheres belonging to the same bundle form a hexagonal-surface-web.From this we conclude that a surface n-web which is formed by n pencils of spheres belonging to the same bundle is a hexagonal web.n pencils of spheres are said to belong to the same bundle,if all the spheres cut a fixed sphere orthogonally.     

Temperature Dependence of the Isobutane Chemical Ionization Mass Spectra of Open-chain and Cyclic Alcohols; Structural,Stereochemical and Molecular-Size Effects. A reevaluation of the isobutane chemical ionization of alcohols

The temperature dependence of the isobutane chemical ionization (CI.) mass spectra of 54 open-chain, cyclic and unsaturated C₅- to C₁₀-alcohols was studied at temperatures ranging from 60 to 250°, and enthalpy changes were calculated for the corresponding main reactions of typical alcohols. The CI. reactivity is controlled by the temperature and the substrate structure as usual, and in addition, by the molecular size. The combination of thermal, structural and substrate-size effects leads to the following main conclusions. At low-reactivity conditions, i.e. at 150° or less, the alcohols with less than 11 C-atoms give four distinct types of spectra, with (M – OH)⁺ usually as the base peak. The characteristic ions are MC₄H₉⁺ and (M – H)⁺ for primary, MH⁺ and (MC₄H₉ – H₂O)⁺ for secondary, (MC₄H₉ – H₂O)⁺ for tertiary and allyl-type alcohols. Configurational assignments of stereoisomeric alcohols are also possible, by means of steric compression and shielding effects. The MH⁺/(M – OH)⁺ ratio in the spectra of epimeric methylcyclohexanols is at least 3 to 4 times higher for the isomers with mainly axial OH-group conformation compared to the equatorial isomers. Stereospecific (M - H)⁺ ions are apparently formed from trans-2-methylcyclopentanol and endo-norbornan-2-ol by a favorable abstraction of the unshielded H(α)-atoms versus normal behavior of the other epimers. While the spectra recorded at 200° show almost exclusively (M – OH)⁺ ions, those at 250° give nevertheless some C-skeleton information through the temperature dependent decomposition of the (M – OH)⁺ ions.