Direct fluorometric analysis of a newly synthesised fluorescein-labelled marker for glomerular filtration rate

There is an obvious and growing medical need for an accurate determination of kidney function in the diagnosis and management of renal diseases. The glomerular filtration rate (GFR) is the accepted gold standard measurement of kidney function. Several approaches to estimate the GFR are available, but most of them are inconvenient and, therefore, of limited acceptance. A new method of quantification with fluorescein-isothiocyanate (FITC) sinistrin (FS), a novel GFR marker, has been evaluated. The method is based on the fluorescence label of FS and can be performed with a standard fluorometer. To control the interference of protein with the fluorescence signal, a calibration function was developed. The accuracy of the fluorometric method established is comparable to the so-called gold standard of enzymatic determination of polyfructosan. Moreover, FS is easy to handle and requires low-cost instruments. Our results demonstrate the potential of the direct fluorometric analysis of the new FITC-labelled marker of being a precise, simple, rapid and cost-effective method for diagnosing disturbed kidney function and monitoring its treatment efficacy. The dramatic decrease in analytical effort will result in a significantly higher acceptability of GFR determination.     

Change of variables in a multiple integral for local fields

A proof of the formula for locally compact fields andC ¹-isomorphisms :UV, whereU andV are open subsets of , was never published. In this paper we give two short proofs, one of them is a more elementary variant of the other.     

Optical Control of a Biological Reaction–Diffusion System

Patterns formed by reaction and diffusion are the foundation for many phenomena in biology. However, the experimental study of reaction–diffusion (R–D) systems has so far been dominated by chemical oscillators, for which many tools are available. In this work, we developed a photoswitch for the Min system of Escherichia coli, a versatile biological in vitro R–D system consisting of the antagonistic proteins MinD and MinE. A MinE‐derived peptide of 19 amino acids was covalently modified with a photoisomerizable crosslinker based on azobenzene to externally control peptide‐mediated depletion of MinD from the membrane. In addition to providing an on–off switch for pattern formation, we achieve frequency‐locked resonance with a precise 2D spatial memory, thus allowing new insights into Min protein action on the membrane. Taken together, we provide a tool to study phenomena in pattern formation using biological agents.     

The detection and location estimation of disasters using Twitter and the identification of Non-Governmental Organisations using crowdsourcing

This paper provides the humanitarian community with an automated tool that can detect a disaster using tweets posted on Twitter, alongside a portal to identify local and regional Non-Governmental Organisations (NGOs) that are best-positioned to provide support to people adversely affected by a disaster. The proposed disaster detection tool uses a linear Support Vector Classifier (SVC) to detect man-made and natural disasters, and a density-based spatial clustering of applications with noise (DBSCAN) algorithm to accurately estimate a disaster’s geographic location. This paper provides two original contributions. The first is combining the automated disaster detection tool with the prototype portal for NGO identification. This unique combination could help reduce the time taken to raise awareness of the disaster detected, improve the coordination of aid, increase the amount of aid delivered as a percentage of initial donations and improve aid effectiveness. The second contribution is a general framework that categorises the different approaches that can be adopted for disaster detection. Furthermore, this paper uses responses obtained from an on-the-ground survey with NGOs in the disaster-hit region of Uttar Pradesh, India, to provide actionable insights into how the portal can be developed further.

     

On some computational problems in finite abelian groups

We present new algorithms for computing orders of elements, discrete logarithms, and structures of finite abelian groups. We estimate the computational complexity and storage requirements, and we explicitly determine the -constants and -constants. We implemented the algorithms for class groups of imaginary quadratic orders and present a selection of our experimental results. Our algorithms are based on a modification of Shanks' baby-step giant-step strategy, and have the advantage that their computational complexity and storage requirements are relative to the actual order, discrete logarithm, or size of the group, rather than relative to an upper bound on the group order.

     

New Spectroscopic Information on 98Pd

Neutron deficient ⁹⁸Pd nuclei were produced in the ⁵⁰Cr(⁵⁸Ni,2p2α)⁹⁸Pd reaction at a beam energy of 261 MeV. A revision and extension of the level structure of ⁹⁸Pd is proposed. About 40 new transitions have been assigned to, and placed in the level scheme of this nucleus. A sequence of states are candidates for the negative parity 4—quasiparticle states built on the πg _9/2 ^?3 πp _1/2 ^?1 configuration predicted in the framework of the nuclear shell model.     

Energy transfer pathways in dinuclear heteroleptic polypyridyl complexes: through-space vs through-bond interaction mechanisms

A series of homo- and heteronuclear ruthenium and osmium polypyridyl complexes with the bridging ligands 1,3-bis(5-(2-pyridyl)-1H-1,2,4-triazol-3-yl)benzene (H(2)mL) and 1,4-bis(5-(2-pyridyl)-1H-1,2,4-triazol-3-yl)benzene (H(2)pL) are reported. The photophysical properties of these compounds are investigated, and particular attention is paid to the heteronuclear (RuOs) compounds, which exhibit dual emission. This is in contrast to phenyl-bridged polypyridine Ru-Os complexes with a similar metal-metal distance, in which the Ru emission is strongly quenched because the nature of the bridging ligand allows for an efficient through-bond coupling. The results obtained for the compounds reported here suggest that energy transfer is predominantly taking place via a dipole-dipole, F?rster type, mechanism, that may dominate when through-bond coupling is weak. This is in stark contrast to ground state interaction, which is found to be critically dependent on the nature of the bridging unit employed.     

Analysis of glycolytic intermediates in Saccharomyces cerevisiae using anion exchange chromatography and electrospray ionization with tandem mass spectrometric detection

The purpose of this study is to selectively and quantitatively analyze several glycolytic intermediates in cells of Saccharomyces cerevisiae using high-performance anion exchange chromatography (HPAEC) coupled to electrospray ionization tandem mass spectrometry for the analysis. A sodium hydroxide gradient is used to separate the glycolytic compounds and after the column sodium hydroxide is reduced by proton exchange with a membrane device prior to introduction to the mass spectrometer. The detection limits for 10 μl samples are down to the 0.4–5 pmol range. This corresponds for the intracellular metabolites to a range of 2–20 nmol per gram biomass dry weight (DW). Standard addition did reveal some influence of the sample matrix on the measured concentrations. Separation and analysis is hardly affected by the high sulfate and phosphate concentrations (1 mM) in the fermentation medium and by the intracellular matrix. Validation of the glucose-6-phosphosphate LC–MS–MS analysis results with enzymatic analysis showed an excellent agreement between the two methods. The suitability of the method was clearly shown by analyzing a series of steady state S. cerevisiae samples from a carbon limited aerobic chemostat culture.