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21.
The present work describes the formulation of alginate microspheres containing diltiazem hydrochloride by the emulsification-internal gelation method with the use of barium carbonate as a cross-linking agent. The effect of various factors (the concentration of alginate and barium chloride) on the drug loading efficiency and in vitro release were investigated. Fourier transform infrared microscopy (FTIR) and differential scanninig calorimetry (DSC) analysis confirmed the absence of any drug polymer interaction. X-ray diffraction (XRD) pattern showed that there is a decrease crystallinity of the drug. The in vitro drug release profile could be altered significantly by changing various processing parameters to give a controlled release of drug from microcapsules. The stability studies of drug-loaded microcapsules showed that the drug was stable at different storage conditions. 相似文献
22.
23.
Herein, we report a facile method for synthesizing MoCo-layered double hydroxide (LDH) nanosheets employing Prussian blue analog (PBA) as the precursor. The introduction of Mo in Co-LDH modulates the electronic structure, increases the number of active sites and electrochemical surface area to improve the hydrogen evolution, oxygen evolution, and overall water splitting activity. As a result, PBA-derived Mo0.25Co0.75-LDH nanosheets demonstrated 10 mA cm?2 current density at only 220 mV and 115 mV overpotentials for OER and HER, respectively. The overall water splitting was attained at 1.52 V cell voltage for 10 mA cm?2 current density. 相似文献
24.
Determination of organophosphate pesticides at a carbon nanotube/organophosphorus hydrolase electrochemical biosensor 总被引:7,自引:0,他引:7
Randhir Prakash Deo Joseph Wang Ines Block Ashok Mulchandani Kanchan A. Joshi Marek Trojanowicz Fritz Scholz Wilfred Chen Yuehe Lin 《Analytica chimica acta》2005,530(2):185-189
An amperometric biosensor for oganophosphorus (OP) pesticides based on a carbon nanotube (CNT)-modified transducer and an organophosphorus hydrolase (OPH) biocatalyst is described. A bilayer approach with the OPH layer atop of the CNT film was used for preparing the CNT/OPH biosensor. The CNT layer leads to a greatly improved anodic detection of the enzymatically generated p-nitrophenol product, including higher sensitivity and stability. The sensor performance was optimized with respect to the surface modification and operating conditions. Under the optimal conditions the biosensor was used to measure as low as 0.15 μM paraoxon and 0.8 μM methyl parathion with sensitivities of 25 and 6 nA/μM, respectively. 相似文献
25.
The ability of small particles to associate with DNA and to transport it to desired targets without being subjected to interferences can make them efficient vehicles for gene delivery. Keeping these requirements in mind, zwitterionic latex particles with two different functional tethers were chosen for studying their interaction with DNA as vehicle complexes. From adsorption and electrokinetic studies, it is evident that zwitterionic latex particles can have marked association with DNA. Moreover, DNA-latex complexation does not provoke undesired aggregation of latex particles. These characteristics are important for it to carry the DNA efficiently under changing media conditions. 相似文献
26.
The field equations of general relativity with electromagnetic stress tensor and zeromass scalar meson field are investigated. The metric coefficients are assumed to be functions of three variables only. It is then shown that, if one assumes a functional relation between some one of the metric coefficients and the electromagnetic potentials, that one can find a solution of the coupled Einstein-Maxwell equations in terms of a solution of the Einstein equations with zeromass scalar meson field as source. 相似文献
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28.
Carbon nanotube fiber microelectrodes 总被引:5,自引:0,他引:5
Carbon nanotube (CNT) fibers have been used to fabricate microelectrodes with an attractive electrochemical behavior. By combining the advantages of CNT materials and fiber microelectrodes, the new material expands the scope of CNT-based electrochemical devices. The CNT fiber offers a marked decrease in the overvoltage for the NADH, dopamine, and hydrogen peroxide and circumvents NADH surface fouling effects. Heat treatment is shown to be extremely useful for activating the CNT fiber surfaces for electron transfer. SEM imaging and cyclic-voltammetric data indicate that the heat treatment leads to the removal of nonconducting residues and exposure of a "fresh" CNT surface. The new electrode material thus presents new opportunities for a wide range of electrochemical and analytical applications. 相似文献
29.
Rohit Deo Mengchen Hsieh Clifford M. Hurvich Philippe Soulier 《Statistical Inference for Stochastic Processes》2000,3(3):291-292
Volume Contents
Volume contents 相似文献30.
C. M. Cattadori M. De Deo M. Laubenstein L. Pandola V. I. Tretyak 《Physics of Atomic Nuclei》2007,70(1):127-132
Recent observation of β decay of 115In to the first excited level of 115Sn with an extremely low Q
β value (Q
β ≤ O(1) [keV]) could be used to set a limit on neutrino mass. To give a restriction potentially competitive with those extracted
from experiments with 3H (≃2 eV) and 187Re (≃15 eV), the atomic mass difference between 115In and 115Sn and energy of the first 115Sn level should be remeasured with higher accuracy (possibly of the order of ∼1 eV).
The text was submitted by the authors in English. 相似文献