Authors:W. Loveland, K. Aleklett, J. Liljenzin, and G. Seaborg
The use of radioanalytical techniques to study heavy ion induced nuclear reactions offers some distinct advantages over conventional physical techniques. Among these are (a) unit Z and A resultion in detecting the reaction products (b) high sensitivity for low probability events (c) lack of low energy thresholds or cutoffs in measuring reactcion product energy spectcra (d) economical use of accelerator time and (e) simple, portable experimental apparatus allowing broad survey measurements of reaction mechanisms at a variety of nuclear particle accelerators. We describe examples of these advantages from our research in nuclear chemistry.
Two wheat genotypes were grown in hydroponic culture, containing 4 mM KNO3, NH4Cl and NH4NO3. Activities of N metabolizing enzymes, aminotransferases, carbohydrate and TCA cycle enzymes were analyzed along with protein, amino acid, N, sugar content and growth parameters in shoot and root. After 12 days, the size of shoot and root system decreased significantly when plants were supplied with NH4Cl as exclusive N source. Under NH4NO3 growth parameters, N and carbon metabolism were elevated as compared to NH4Cl but less than KNO3 source indicating inhibition of NH4+ toxicity by NO3− uptake. Our results suggested that GDH, aminotransferases and PEPC play an important role in ammonium detoxification by its incorporation into amino acids. Thus, the morphologic differences among plants growing in NH4+ or NO3− nutrition confirm the hypothesis that N source determines the growth habit of plant in wheat by modulating the endogenous levels of protein and sugar content.
Authors:J. Horn, H. Semmelhack, H. Börner, and F. Schlenkrich
We propose a reaction model for the synthesis of YBa2Cu4O8 under normal pressure conditions, which contains 4 partial reaction steps. In a first step bariumnitrate and copperoxide
react to Ba2Cu3O5+δ. This substance will be formed for each mixtures Ba:Cu=2∶3...3∶2. The following two partial reaction steps are connected
to Ba2Cu3O5+δ, which reacts with Y2O3 and CuO to YBa2Cu4O8 or decomposes to BaCuO2 and CuO. In a last step parts of BaCuO2 reacts with Y2O3 and CuO to YBa2Cu4O8.
Authors:Kailas P. Patil, Atul S. Patil, Anil B. Patil, Pallavi M. Kulkarni, Vijay R. Chandegaonkar, and Bhausaheb P. More
2,4-Dichlorophenoxyacetic acid (2,4-D) is a phenoxy group of herbicide used worldwide. As it is extensively used, it has consequential problems on living beings. 2,4-D is degraded into the chlorinated phenols and catechols, and these phenol compounds are more hazardous than the parent 2,4-D herbicide. In this paper, an attempt is made to detect 2,4-dichlorophenol in 2,4-D poisoning cases from human viscera. Sensitive and selective detection of 2,4-dichlorophenol using high-performance thin-layer chromatography (HPTLC) is possible by coupling it with 4-amminoantipyrene in the presence of potassium ferricyanide. Standard 2,4-dichlorophenol and human visceral extract are allowed to run on an HPTLC plate with hexane, acetone, and ethyl acetate as the mobile phase. Mechanistically, 4-amminoantipyrene reacts with 2,4-dichlorophenol in the presence of potassium ferricyanide to form p-quinoneimide which is brick red in color. This known reaction is, for the first time, applied to detect 2,4-dichlorophenol in 2,4-D poisoning cases from human viscera. The formation of brick red color spot on the HPTLC plate allows the easy and confirmed detection of 2,4-dichlorophenol in 2,4-D poisoning case. This HPTLC method is simple and easy to work in laboratory. The reagents do not react with the parent 2,4-dichorophenoxyacetic acid and other organophosphorus, organochlorine, carbamate, and pyrethroid insecticides, i.e., these reagents are specific. The constituents of the viscera (amino acids, peptides, proteins, etc.) and plant material do not interfere with the reagents. The presence of 2,4-dichlorophenol in the same visceral sample is confirmed by gas chromatography-mass spectrometry (GC-MS). The detection limit of reagents for 2,4-dichlorophenol is approximately 0.5 µg.
description, the following terms will be used: the first element , to refer to the first part of a discontinuous phrase, and the second element , to refer to the last part of this construction. The place of the gap will be called the intermediate area
, and sometimes dependent, to the Asia/Europe intermediates market. The dependence cited here has an incredible effect on the final manufacturing price but also on the choice of synthetic route. In this way, the choice of drug candidate for continuous