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81.
Jaleel CA Manivannan P Kishorekumar A Sankar B Gopi R Somasundaram R Panneerselvam R 《Colloids and surfaces. B, Biointerfaces》2007,59(2):150-157
Catharanthus roseus (L.) G. Don plants were grown in different water regimes in order to study the drought induced osmotic stress and proline (PRO) metabolism, antioxidative enzyme activities and indole alkaloid accumulation. The plants under pot culture were subjected to 10, 15 and 20 days interval drought (DID) stress from 30 days after sowing (DAS) and regular irrigation was kept as control. The plants were uprooted on 41 DAS (10 DID), 46 DAS (15 DID) and 51 DAS (20 DID). The drought stressed plants showed increased aminoacid (AA), glycine betaine (GB) and PRO contents and decreased proline oxidase (PROX) and increased γ-glutamyl kinase (γ-GK) activities when compared to control. The antioxidative enzymes like peroxidase (POX) and polyphenol oxidase (PPO) increased to a significant level in drought stressed plants when compared to control. The drought stressed C. roseus plants showed an increase in total indole alkaloid content in shoots and roots when compared to well-watered control plants. Our results suggest that the cultivation of medicinal plants like C. roseus in water deficit areas would increase its PRO metabolism, osmoregulation, defense system and the level of active principles. 相似文献
82.
83.
Anna Irto Paola Cardiano Karam Chand Rosalia Maria Cigala Francesco Crea Concetta De Stefano Maria Amlia Santos 《Molecules (Basel, Switzerland)》2021,26(23)
The binding ability of five bifunctional 3-hydroxy-4-pyridinones towards Cu2+ and Fe3+ was studied by means of potentiometric and UV–Vis spectrophotometric measurements carried out at I = 0.15 mol L−1 in NaCl(aq), T = 298.15 K and 310.15 K. The data treatments allowed us to determine speciation schemes featured by metal-ligand species with different stoichiometry and stability, owing to the various functional groups present in the 3-hydroxy-4-pyridinones structures, which could potentially participate in the metal complexation, and in the Cu2+ and Fe3+ behaviour in aqueous solution. Furthermore, the sequestering ability and metal chelating affinity of the ligands were investigated by the determination of pL0.5 and pM parameters at different pH conditions. Finally, a comparison between the Cu2+ and Fe3+/3-hydroxy-4-pyridinones data herein presented with those already reported in the literature on the interaction of Zn2+ and Al3+ with the same ligands showed that, from the thermodynamic point of view, the 3-hydroxy-4-pyridinones are particularly selective towards Fe3+ and could therefore be considered promising iron-chelating agents, also avoiding the possibility of competition, and eventually the depletion, of essential metal cations of biological and environmental relevance, such as Cu2+ and Zn2+. 相似文献
84.
Pankaj Kumar S. C. Jain Vikram Kumar Suresh Chand R. P. Tandon 《Applied Physics A: Materials Science & Processing》2009,94(2):281-286
Current–voltage (J–V) characteristics of organic bulk heterojunction diodes based on an interpenetrating network of poly(3-hexylthiophene) (P3HT)
and [6,6]-phenyl C61-butyric acid methyl esters (PCBM) have been studied in the dark and under halogen lamp illumination. The diodes contained
1:1 and 1:0.6 weight ratios of P3HT and PCBM. For both diodes the currents measured in dark (J
d
, commonly known as the dark current) in forward bias are found to agree with the space charge limited current (SCLC). The
illuminated current consists of a current due to applied voltage (J
da
) and the light generated current (J
L
). J
da
extracted from the illuminated current agrees well with Shockley’s diffusion and recombination current. This observation
shows that illumination changes the SCLC into Shockley’s diffusion and recombination current. The forward current under illumination
has been observed to be greater than the dark current, which is contrary to the photo–voltaic (PV) theory. This result is
well explained by the change of SCLC into Shockley’s diffusion and recombination current.
Former address of S.C. Jain: IMEC, Kapeldreef 75, 3001 Leuven, Belgium. 相似文献
85.
In the present work we have employed allyl diglycol carbonate (CR-39) and cellulose triacetate (CTA) plastic for detection
of neutron recoil tracks without radiator. For CR-39, the results reveal that registration efficiency is a function of duration
of chemical pre-etching and the best results are obtained with chemical pre-etching of 3 hours. It was also investigated that
the ac field strength of 28 kV/cm having 2.5 kHz frequency was optimum for revelation of tracks. Interestingly the sensitivity
is fluence dependent and it was constant up to a fluence of about 108 n/cm2. The sensitivity abruptly decreased with increased fluence. At optimum experimental conditions the minimum detection limit
for CR-39 was found to be 0.47 mSv. For CTA, the tracks have been revealed by electrochemical etching (ECE) only and the minimum
detection limit was found to be 0.85 mSv at optimum experimental parameters.
相似文献
86.
Manjula Spah Dal Chand Spah Sooyoung Jun Seungmoon Lee Ho-Jun Song Koh Won-Gun Jin-Won Park 《Fluid Phase Equilibria》2009
The EMF data of different metal chlorides (2:1 electrolytes) were obtained by using a cell [MX Hg|MCl2 (m)|AgCl–Ag] at two temperatures. Stock solutions of metal chlorides (CoCl2, CuCl2 and ZnCl2) were prepared by weight in 1,4-dioxane–aqueous mixtures. There was a significant change in the EMF values with change of metal chloride, its concentration and solvents composition. The standard electrode potential (E°) values of the above cell were calculated from the measured EMF of these mixtures. The standard thermodynamic functions (ΔG°, ΔH° and ΔS°) and respective transfer parameters of MCl2 from water to 20, 45 and 70% dioxane–water mixtures were also evaluated. Equilibrium dissociation constants (K1 and K2) as well as the degrees of dissociation (α1 and α2) were obtained by iterative procedures. The data were analyzed in terms of solute–solvent interactions depending on standard and transfer thermodynamic parameters and mean activity coefficients (γ±) of electrolytes. 相似文献
87.
Chakraborty TK Roy S Koley D Dutta SK Kunwar AC 《The Journal of organic chemistry》2006,71(16):6240-6243
Cyclic oligomers of tetrahydrofuran amino acids, cyclo-(Taa1-Leu-Val)2 (left), cyclo-(Taa2-Leu-Val)2 (middle), and cyclo-(Taa2-Phe-Leu)2 (right), displayed well-defined intramolecularly hydrogen-bonded structures with distorted "beta-beta corner" motifs similar to the tennis ball seam. 相似文献
88.
Oscillating multidromion excitations in higher-dimensional nonlinear lattice with intersite and external on-site potentials using symbolic computation
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We show by an extensive method of quasi-discrete multiple-scale approximation that nonlinear multi-dimensional lattice waves subjected to intersite and external on-site potentials are found to be governed by (N +1)-dimensional nonlinear Schro¨dinger (NLS) equation. In particular, the resonant mode interaction of (2+1)-dimensional NLS equation has been identified and the theory allows the inclusion of transverse effect. We apply the exponential function method to the (2+1)-dimensional NLS equation and obtain the class of soliton solutions with a purely algebraic computational method. Notably, we discuss in detail the effects of the external on-site potentials on the explicit form of the soliton solution generated recursively. Under the action of the external on-site potentials, the model presents a rich variety of oscillating multidromion patterns propagating in the system. 相似文献
89.
The effect of Dzyaloshinskii-Moriya (D-M) interaction on the bistable nano-scale soliton switching offers the possiblity of developing a new innovative approach for data storage technology. The dynamics of Heisenberg ferromagnetic spin system is expressed in terms of generalized inhomogeneous higher order nonlinear Schrödinger (NLS) equation. The bistable soliton switching in the ferromagnetic medium is established by solving the associated coupled evolution equations for amplitude and velocity of the soliton using the fourth order Runge-Kutta method numerically. 相似文献
90.
Manish Chand Deborah S. Keller Laurence Devoto Mark McGurk 《Journal of fluorescence》2018,28(2):483-486
To describe an innovative sentinel lymph node (SLN) guidance approach using a radionuclide tracer, 3D augmented reality-guided imaging, and near infrared (NIR) fluorescence over-lay imaging with hand-held probes to optimize accuracy, efficiency, and precise navigation for sentinel node (SN) localization in head and neck cancer. In a cT1N0M0 squamous cell carcinoma of the tongue, pre-operative radionuclide lymphoscintigraphy was performed with a sentinel node-specific radiolabeled tracer. Intraoperatively, a 3D hand-held augmented reality (AR) scanning SPECT probe assessed concordance of the SN with pre-operative SPECT-CT images. The real-time optical video was linked to the SPECT-CT images for added precision. Final guidance to the SN was performed using ICG fluorescence imaging. Dynamic and SPECT-CT showed bilateral lymphatic drainage from the tumor. The 3D hand-held AR SPECT probe SN localization was concordant with pre-operative imaging. The optical video successfully demonstrated the lymphatic drainage in real-time through a unique overlay fluorescence image. The ICG localized to the same nodes identified by both the SPECT-CT and hand-held SPECT images. The use of dual radiation and fluorescence tracers improved SN detection, especially for SN close to the injection site. The hand-held probes allowed the surgeon to dissect continuously, without needing to change tools. The combination of augmented reality, nuclear medicine, and over-lay fluorescence imaging allowed greater accuracy for matching the preoperative imaging with intraoperative identification and precisely guiding the dissection. This method uniquely permitted the surgeon to efficiently dissect the SN with accurate visualization and optimal precision. 相似文献