Anion-exchange initiation of reactions: Detection and spectrophotometric determination of aliphatic amines with 2,4-dinitrophenylhydrazine

The role of anion-exchange resin beads in the initiation of reactions of tertiary amines with 2,4-dinitrophenylhydrazine has been explored. This reagent has been used for the selective detection and determination of aliphatic amines. Radiochemical studies have been performed to show that the coloured species is adsorbed but not exchanged on ion-exchange beads. A model for the interaction is proposed.     

Studies of Amperometric glucose dehydrogenase electrodes for glucose

Glucose sensors are constructed by immobilizing glucose dehydrogenase physically or chemically on a carbon or platinum electrode. Soluble coenzyme was used. The usefulness of the electrode is limited by interference from any molecule that can be oxidized at + 450 mV. Because the cofactor must be in solution, and diffuse to the electrode, a low-molecular-weight cut-off filter cannot be used to block the interferences.     

Discovery of the second highest level of radioactive mineral spring in Iran

Summary One of the high-level natural radiation areas (HLNRAs) in Iran is located in the south of Iran in the Hormozgan province. Uranium and its daughters, such as radium and thorium cause areas of elevated natural radiation. An unknown hypothermal mineral and radioactive spring was discovered containing high-level radiation, 42 mSv ^. y^-1 maximum effective dose around spring was measured. ⁴⁰K, ²²⁶Ra and ²³²Th radionuclides were detected with the maximum activity of 11.80 Bq ^. l^-1, 3.48 Bq ^. l^-1 and 2.52 Bq ^. l^-1, respectively. These activities are the second highest in comparison to those in the Ramsar radioactive springs, especially Ab-e-siah spring, which contains 146.5 Bq ^. l^-1 activity. Ocillatoria spp., Lyngbya spp. and a kind of ciliatawere observed in this spring. The results showed that the radioactive spring falls into the sodium chloride category.     

Effect of temperature,humidity and pressure on electric properties of the cells based on PTB7-Th,PC61BM and graphene composite

Journal of Thermal Analysis and Calorimetry - In this paper, fabrication and characterization of Cu/PTB7-Th (35 mass%)/PC $$_{61}$$ BM (35 mass%)/graphene (30 mass%)/Ag...     

Enzymatic determination of vitamin A in pharmaceutical formulations with spectrophotometric detection

An enzymatic method for the determination vitamin A (retinol) is reported using soluble and immobilized alcohol dehydrogenase, isolated from rabbit liver. The reaction is based on the oxidation of retinol and simultaneous reduction of NAD⁺ to NADH followed by spectrophotometric detection at 340 nm. The calibration graph was linear over the range of 2.0–10 μM with correlation coefficients of 0.9967 and 0.9992 (n = 5) for soluble and immobilized alcohol dehydrogenase respectively, with relative standard deviations (n = 3) in the range of 0.5–1.2%. The limit of detection was lower than 1.0 μM. The proposed method was applied to determine vitamin A in pharmaceuticals, and the results obtained were in reasonable agreement with the amount labeled. The results were compared using spectrophotometric reference method, and no significant difference was found between the results of the both methods.     

Nanogram detection of m-dinitroaromatics and their derivatives A re-evaluation of the spot-test based on the janovsky reaction

The spot-test for m-dinitroaromatics and their derivatives, based on the Janovsky reaction, is re-investigated. The sensitivity of the spot-test has been much enhanced by changing the solvent and using the novel “pellet” spot-test. With the “pellet” spot-test and dimethylsulphoxide, 4–50 ng of m-dinitroaromatic compounds and their derivatives can be detected. The change from acetone (used in the original spot-test) to dimethylsulphoxide changes the reaction product in most cases.     

Bioluminescent assays with immobilized firefly luciferase based on flow injection analysis

A flow-injection manifold incorporating immobilized firefly luciferase is described. The detector design and reaction conditions are discussed and results are presented for the determination of adenosine-5′-triphosphate over the range 1 × 10^?12?1 × 10^?5 M. Modifications for creatine phoshokinase (10–400 U l^?1) and creatine phosphate (10^?t–10^?1 M), both determined indirectly via ATP, are also described.     

Field method for the micro-quantitative determination of tetracycline in human urine

A simple, fast and sensitive titrimetric method has been developed for the determination of tetracycline hydrochloride in human urine using m-dinitrobenzene as color agent and Dowex 1 × 8 as detection medium. Received: 26 February 1997 / Revised: 23 April 1997 / Accepted: 29. April 1997     

Anticancer Activity of Cordia dichotoma against a Panel of Human Cancer Cell Lines and Their Phytochemical Profiling via HPLC and GCMS

The current study was conducted to examine the in vitro anticancer potential of Cordia dichotoma (bark, leaves, pulp and seed). The plant material was collected from UT of J&K and methodical bioassays were carried out on ten human cancer cell lines (Michigan Cancer Foundation-7 (MCF-7), M.D. Anderson-Metastatic Breast (MDA-MB-231), Neuroblastoma-2a (N2A), SH-SY5Y, U-251, HCT-116, SW-620, A-549, MIA PaCa-2, Panc-1) from five different origins (breast, CNS, colon, lung, pancreas) respectively. Methanolic extracts were produced and fractions were then obtained from the extracts and evaluated for cytotoxicity. Mechanistic assays, HPLC, and GCMS profiling were performed on the highest active fraction. The Sulforhodamine B (SRB) assay determined the in vitro cytotoxicity. The findings revealed that the bark portion had in vitro cytotoxicity against the A-549 human lung cancer cell line. To our knowledge, this is the first study to show that the plant’s bark has anticancer properties and induced chromatin condensation, confirmed cell death via ROS generation, and significantly decreased colony formation in A-549 cell line from lung origin in a dose-dependent manner. Furthermore, HPLC and GCMS investigations indicated the presence of a number of bioactive molecules such as gallic acid (144,969.86) uV*sec, caffeic acid (104.26) uV*sec, ferulic acid (472.87) uV*sec, vanillic acid (13,775.39) uV*sec, palmitic acid (18.34%), cis vaccenic acid (28.81%), etc. and one of the compounds was reported for the first time from the bark. As a result of its promising efficacy, it may become an essential cancer chemopreventive or chemotherapeutic medication for patients with lung carcinoma.