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71.
Cell suspension cultures of Arnebia euchroma were established from the friable callus on liquid Murashige and Skoog medium supplemented with 6-benzylaminopurine (10.0 μM) and indole-3-butyric acid (5.0 μM). Salicylic acid was used to study its effect on the enzymes which participate in shikonin biosynthesis with respect to metabolite (shikonin) content in the cell suspension culture of A. euchroma. In our study, phenylalanine ammonia lyase and PHB geranyltransferase were selected from the entire biosynthetic pathway. Results showed that phenylalanine ammonia lyase is responsible for growth and PHB geranyltransferase for metabolite production. Salicylic acid exhibited an inverse relationship with the metabolite content (shikonin); salicylic acid (100 μM) completely inhibited shikonin biosynthesis. The results presented in the current study can be successfully employed for the metabolic engineering of its biosynthetic pathway for the enhancement of shikonin, which will not only help in meeting its industrial demand but also lead to the conservation of species in its natural habitat.  相似文献   
72.
Pinorox® is a standardized composition obtained from pine bark extract of Pinus roxburghii, rich source of natural polyphenols - Oligomeric Proanthocyanidins (OPCs) compounds that act as an antioxidant. Pinorox® has been expected to serve as potential natural supplement consumed to enhance the physical endurance in normal healthy or a sport person. Hence, double-blind, randomized, placebo-controlled study was conducted for time period of 90 days to validate the effect of Pinorox® over physical and athletic performances in normal healthy as well as sports subjects. 50 eligible subjects were selected through screening and distributed into placebo and Pinorox® groups. The subjects utilized in the present study i.e., healthy individual and athletes received one of either 200 mg of Pinorox® or experimental control (placebo) for 90 days. Each subject was evaluated for increase in physical or athletic performances by observing changes from baseline in rate of oxygen consumption VO2 max (endurance) compared to placebo at baseline, assessment of anaerobic power and rate of fatigue by using Wingate test at baseline, changes in assessment values using 1-RM test and muscle grip strength assessment using handheld dynamometer at baseline and during the interval of 90 days. The observations discussed in the present study shows that people consuming Pinorox® displayed significantly advanced performances during exercising or performing given sports activities. Improvement in the VO2 max values, anaerobic power, rate of fatigue, muscular performance and muscle grip strength was observed in test results and the study did not report any adverse effect. Overall, the study demonstrates that Pinorox® is a safe, fast acting and effective natural dietary or sport supplement for enhancing physical and athletic performances.  相似文献   
73.
Electroluminescence (EL) emission has been observed under AC field excitation in chemically deposited (dipping technique) films of (Zn‐Cd)S:Cu,F using substrates of conducting glass plates. Results of XRD, SEM, absorption spectra, transmission spectra, EL emission spectra, voltage, frequency and temperature dependence and brightness waves of EL brightness are presented and discussed. SEM studies show better growth condition in presence of F. X‐ray diffraction studies show diffraction lines due to CdS and ZnS. Both the studies represent average particle sizes of the order of 1Å. Absorption studies show change in band gap due to increasing concentration of ZnS. The observed EL emission (blue‐green region) may be due to Cu, F combination. Results of transmission spectra give band gap similar to those given by absorption spectra. From voltage dependence of EL brightness acceleration‐collision mechanism is found to be effective. Frequency dependence of EL brightness shows first an increase in brightness in the lower frequency range followed by saturation at higher frequencies. Temperature dependence of EL emission shows a maximum at 40°C. Brightness waves consist of primary and secondary waves, which depend on voltage and frequency of excitation & the ambient temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
74.
75.
Picroside‐I and picroside‐II are known bioactive metabolites in Picrorhiza species. In the present study a simple, precise method has been established for the simultaneous determination of picrosides (picroside‐I and picroside‐II) in two different Picrorhiza species, P. kurroa and P. scrophulariiflora. This method was also validated for accuracy, precision, robustness, limit of detection and quantification, repeatability and recovery, according to International Conference of Harmonization guidelines. Separation and quantification was achieved by HPTLC using as the mobile phase chloroform–methanol (88:12, v/v) on precoated silica gel 60F254 aluminum plates. Densitometric determination was carried out at wavelength λmax 254 nm in UV absorbance mode. Comparative study also revealed that picroside‐I and picroside‐II are higher in P. scrophulariiflora than P. kurroa. Picroside‐I content was found to be 1.258 and 1.611%, and picroside‐II was estimated as 0.481 and 0.613% in P. kurroa and P. scrophulariiflora, respectively. Antioxidant potential of these two Picrorhiza species was also studied using DPPH. At a concentration of 0.1 mg/mL the scavenging activities of P. kurroa and P. scrophulariiflora were found to 37.70 and 34.30%, respectively. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
76.
Two-neutrino ββ decay matrix elements and half-life of 48Ca are calculated after including neutron-proton pairing correlations in projected Hartree-Fock-Bogoliubov (PHFB) formalism. The GT matrix elements in 2νββ decay are reduced due to broader smearing of Fermi surfaces. Half-life results for 2νββ decay of 48Ca with np pairing are better than without pairing.  相似文献   
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78.
ABSTRACT. In this paper a nonlinear mathematical model to study effects of primary and secondary toxicants on the biomass of resources such as forestry, agricultural crops, etc., is proposed and analyzed. The primary toxicant is emitted into the environment with a constant prescribed rate by an external source and a part of which is transformed into a secondary toxicant, which is more toxic, both affecting the resource simultaneously. By using stability theory of differential equations, it is shown that the biomass density of resource attains an equilibrium level, the magnitude of which is smaller than its original (toxicant independent) carrying capacity and it decreases as the emission rate of primary toxicant increases. It is also shown that the decrease in biomass density of resource is more than the corresponding case of a single toxicant due to large transformation and uptake rates and high toxicity of secondary toxicant. It is pointed out that the resource may even become extinct if emission rate of primary toxicant and transformation rate of secondary toxicant are very large and their effects on resource are sufficiently harmful due to large uptake and high toxicity of secondary toxicant which is more toxic.  相似文献   
79.
The 5′ amino-labeled DNA probe complementary to mga gene of Streptococcus pyogenes was immobilized on carboxylated multiwall carbon nanotubes electrode and hybridized with 0.1–100 ng/6 μl single-stranded genomic DNA (ssG-DNA) of S. pyogenes from throat swab of suspected rheumatic heart disease (RHD) patients. Electrochemical response was measured by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance (EI). The sensitivity of the sensor was 106.03?(μA/cm2)/ng and limit of detection (LOD) was found 0.014 ng/6 μl with regression coefficient (R 2) of 0.921 using DPV. The genosensor was characterized by FTIR and SEM, and electrode was found stable for 6 months on storage at 4 °C with 5–6 % loss in initial DPV current. mga genosensor is the first report on RHD sensor which can save life of several suspected patients by early diagnosis in 30 min.  相似文献   
80.
Flavanones have been synthesised by cyclisation of 2′-hydroxychalones with potassium ferricyanide using phase transfer catalysis.  相似文献   
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