Recent x-ray backlight source development at KMS

G4-NASBA: An ultra-fast, highly sensitive and portable isothermal detection system for diagnosing influenza A virus.

Chapter 34 - Detection of Viable Oocysts of Cryptosporidium Parvum by Nucleic Acid Sequence Based Amplification (NASBA)

The origin of gas-liquid partition chromatography is generally taken to be a 1941 comment by A. J. P. Martin indicating that it should be possible to use a gas and a liquid in a partition Chromatographic separation (Martin and Synge, 1941). In 1948–1949 experimental work was undertaken, and the results of the first successful experiments were published in 1952 (James and Martin, 1952). The separation of fatty acids was studied, and the theoretical basis of GLC separations was discussed. The separation of organic amines was investigated in later work. The need for gas phase detection systems became evident as soon as compounds other than acids and bases were studied. The separation of hydrocarbons, for example, was (and is) an application of great importance to the petroleum industry, but this separation problem could not be studied effectively without suitable detectors. During the next few years many types of detection systems were developed. The “gas density balance” of Martin and James (1956) had moderately high sensitivity. The response was on a molar basis, and this detector was used extensively at Mill Hill (National Institute for Medical Research, London). Thermal conductivity detection systems (Claesson, 1946; Ray, 1954) came into wide use in studies where the sample was relatively large, while the argon ionisation detector with a radium foil source was used as a sensitive detection system with microgram samples (Lovelock, 1958). The hydrogen flame ionization detection system was developed through work in several laboratories around 1957–1958, and this detector is now used universally in quantitative work with samples down to about 0.01 μg.

A highly sensitive and reliable tunable diode laser absorption spectroscopy gas detection system with a temperature-pressure compensation algorithm is demonstrated for detecting C H 4 concentrations in near space. Near space generally refers to the airspace 20-100km away from the ground, where temperature and pressure changes are complex. Since the gas absorption spectrum is easily affected by temperature and pressure, a temperature-pressure compensation algorithm is proposed and used in the C H 4 sensor to improve the detection accuracy of the sensor. First, we measured the basic characteristics of the sensor in the laboratory, such as linearity and long-term stability. Experimental results showed that the linear correlation coefficient R-square can reach 0.999, and the concentration fluctuation of C H 4 is less than 0.17ppm within 3.5h. Then the sensor was applied to a research activity in Qinghai Province, China, in September, and the results show that the sensor can effectively monitor the C H 4 concentration in near space.

Ion beam induced fluorescence imaging in biological systems

High performance liquid chromatography(HPLC)using a multiwave detector possesses the advantage of being able to measure both the absorption spectra and the retention time. But conventional multiwave detector with diode arrays has lower sensitivity than commercial single wave UV detector with photomultiplier tubes and shows a marked decrease of sensitivity in the UV region below200n m. With our multiwave HPLC detection system, mechanical scanning with a rotary slit is conducted with a photomultiplier that has full sensitivity in the wavelength renge of160-650nm. And absorption due to oxygen below the200nm wavelength region has been inhibited by filling the optical system with nitrogen . This has resulted in an improvement in this system's detection sensitivity enabling it to measure in the UV region below200nm. Using this system, we tried out multiwave HPLC analysis for a number of clinical chemically important saccarides and amino acids without using some coloring reagents. As a result of this it was found possible to detect absorption peaks of each component below a wavelength of200nm, and the possibility of conducting qualitative analysis from the absorption spectra of the components was also demonstrated.

Hourglass-inspired total analysis system for the sensitive colorimetric detection of exosomal miRNA using the CRISPR-Cas12a system with isothermal amplification

Beta-N-acetylhexosaminidase was prepared from a liver lysosomal fraction obtained from rats between 18 days of gestation (group I) and 72 weeks of age (groups II-VI). A glycan chain analysis was performed after an electrophoresis and blotting, followed by a very sensitive detection system with highly specific digoxigenin-labelled lectins. The presence of high-mannose/hybrid type glycans, as well as their fucosylated forms was shown in all the experimental groups. Complex-type glycans with terminal sialic acid or galactose were present in all the groups except for 1-week-old rats in which only a positive reaction with lectins from Galanthus nivalis and Aleuria aurantia was observed. Thus it may be assumed that age-related changes in the glycosylation pattern occur on the first days after birth.

A new solid-phase extraction procedure for urinary 3-methoxy-4-hydroxy-phenylethyleneglycol (MHPG) was established. Sep-Pak Diol cartridge was used, because MHPG is a neutral and alcoholic compound. Aqueous samples were adsorbed to the cartridge, then MHPG was eluted by the addition of ethyl acetate. After the eluate was evaporated, the residuum was dissolved with HPLC mobile phase and injected into HPLC. The extraction procedure was highly specific to MHPG, and none of other acidic catecholamine metabolites, such as vanillylmandelic acid (VMA), homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC), was extracted. The recovery of MHPG using this method was over 90% and higher than those using previously described methods such as liquid-liquid extraction with ethyl acetate. Of the three vanillyl alcohol isomers, isovanillyl alcohol was the most suitable as an internal standard for the correction of column-to-column variation of the recovery. Human urinary unconjugated MHPG extracted by the new procedure could be measured by HPLC with a fluorescence detection. Further complicated derivatization and more sensitive detection systems, such as GC-MS and HPLC-electrochemical detector (ECD), were not needed due to high selectivity and high recovery of the extraction procedure. In addition, the urinary total (conjugated plus unconjugated) MHPG content could also be determined by the same procedure after an enzymatic hydrolysis of conjugated MHPG. The newly developed extraction procedure was simple, rapid and highly specific, and might be applicable to the analysis of MHPG in various body fluids.

This report describes a microfluidic approach for allele-specific extension of fluorescently labeled nucleotides for scoring of single nucleotide polymorphism (SNP). The method takes advantage on the fact that the reaction kinetic differs between matched and mismatched configurations of allele specific primers hybridized to DNA template. By combining reaction kinetics of the extension reaction and flow kinetics of a microfluidic device, mismatched configurations were discriminated from matched configurations. All three possible variants of a SNP site at codon 72 of the p53 gene were scored using our approach. The result in this work demonstrates the possibility of scoring SNP by allele-specific extension of fluorescently labeled nucleotides in a microfluidic flow-through device. The sensitive detection system and easy microfabrication of the microfluidic device enable further miniaturization and production of an array format of filter-chambers for high throughput SNP analysis.

The production and detailed immunostaining properties of a new rat monoclonal antibody (ICR.2) to epithelial membrane antigen are reported. The antibody was selected for its ability to compete with the polyclonal antiserum (M7), used in the original immunohistological studies, in order that it might serve as a direct replacement in diagnosing epithelial tumours. Most of the staining reactions on normal tissues were identical to those previously reported with M7 but there were some important differences. They included: positivity of renal and adrenal capsular fibroblasts, perineurium, some myoepithelial and smooth muscle cells, occasional osteoblasts and squamous and thyroid follicular epithelium in the normal state. The intercellular canaliculi of sweat glands and secretory canaliculi of gastric oxyntic cells were clearly demonstrated. These staining reactions could be obtained with M7 when a sensitive detection system was used although the results were usually weak and inconsistent. Nearly all adenosquamous and transitional carcinomas were positive. The remaining tumours fell into three major groups: (1) those which were consistently or nearly consistently negative--melanoma, seminoma, rhabdomyosarcoma, alveolar soft part sarcoma, adrenal cortical carcinoma, granulocytic sarcoma, paraganglioma, non-Hodgkin's lymphoma. Hodgkin's disease and embryonal carcinoma: (2) those which were either negative or positive with distinctive patterns of staining--basal cell carcinoma, embryonal tumours: and (3) non-epithelial tumours that were consistently positive--epithelioid sarcoma, synovial sarcoma, osteosarcoma, chordoma and myeloma--or positive in a significant minority of cases--leiomyosarcoma, malignant fibrous histiocytoma, clear cell sarcoma of tendon sheath, various neuroectodermal tumours.(ABSTRACT TRUNCATED AT 250 WORDS)

Using synchrotron X-ray fluorescence microprobes in the study of metal homeostasis in plants

Self-correcting ratiometric fluorescence assay for H2S detection in live cells and releasing agents

Fast analysis of narcotic drugs by optical chemical imaging

Applicability of capillary zone electrophoresis to study metal complexation in solution