The first step toward developing complete cell circuitry is to build quantitative networks for enzyme reactions. The conventional King-Altman-Hill (KAH) algorithm for topological analysis of enzyme networks, adapted from electrical networks, is based on “Reaction Graphs” that, unlike electrical circuits, are not quantitative, being straightforward renderings of conventional schematics of reaction mechanisms. Therefore, we propose the use of “Reaction Route (RR) Graphs” instead, as a more suitable graph-theoretical representation for topological analysis of enzyme reaction networks. The RR Graphs are drawn such that they are not only useful for visualizing the various reaction routes or pathways, but unlike Reaction Graphs possess network properties consistent with requisite kinetic, mass balance, and thermodynamic constraints. Therefore, they are better than the conventional Reaction Graphs for topological representation and analysis of enzyme reactions, both via the KAH methodology as well as via numerical matrix inversion. The difference between the two is highlighted based on the example of a single enzyme reaction network for the conversion of 7,8-dihydrofolate and NADPH into 5,6,7,8-tetrahydrofolate and NADP+, catalyzed by the enzyme dihydrofolate reductase. 相似文献
Russian Journal of Organic Chemistry - A simple, green, and efficient protocol has been developed for the synthesis of biologically active 1,4dihydropyrano[2,3c]pyrazole derivatives via one-pot... 相似文献
It is of immense interest to exert spatial and temporal control of chemical reactions. It is now demonstrated that irradiation can trigger reactions specifically at the surface of a simple colloidal construct, obtained by adsorbing polyethyleneimine on fluorescent colloidal particles. Exciting the fluorescent dye in the colloid affords photoinduced electron transfer to spatially proximal amine groups on the adsorbed polymer to form free radical ions. It is demonstrated that these can be harnessed to polymerize acrylic acid monomer at the particle surface, or to break up colloidal assemblies by cleaving a cross‐linked polymer mesh. Formation of free radical ions is not a function of the size of the colloid, neither is it restricted to a specific fluorophore. Fluorophores with redox potentials that allow photoinduced electron transfer with amine groups show formation of free radical ions. 相似文献
Antimicrobial properties casing wide applicability in water detoxification, pharmaceutics and in industries. Present work focus on the synthesis of a new series of Schiff Bases (E)-4-(1 substituted-1H Benzo[d]imidazole-2-yl)-N'-(substituted Benzylidene)benzohydrazide (5a-5l) were synthesized. The convenient route for the synthesis of new analogues by the condensation of 4-(substituted -1H-Benzo[d]imidazole-2-yl)-N'- Hydrazine with different derivatives of aromatic aldehydes were described using different solvents and catalysts. The structures of the synthesized compounds were ascertain by spectral techniques viz. IR, 1H NMR, MS and Physical Elemental data. Compounds were also subjected to thermal analysis to study their physical and chemical properties. The title compounds were also screened for their antimicrobial activity against various bacterial & Fungal strains. Results of bioassay vary with diverse group attached to Benzimdazole motif and could be helpful for the development of other bioactive molecules. 相似文献
Amide and ester conjugates of aceclofenac with polyamidoamine (PAMAM-G0) dendrimer zero generation and dextran (40 kDa) polymeric
carrier, respectively, are presented. The prepared conjugates were characterized by UV, TLC, HPLC, IR, and 1H NMR spectroscopy. The average degrees of substitution of amide and ester conjugates were determined and found to be (12.5
± 0.24) % and (7.5 ± 0.25) %, respectively. The in vitro hydrolysis studies showed that dextran ester conjugate hydrolyzed
faster in a phosphate buffer solution of pH 9.0 as compared to PAMAM dendrimer G0 amide conjugate, and followed the first
order kinetics. No amount of the drug was regenerated at pH 1.2 in simulated gastric fluid. The dextran conjugate showed short
half-life as compared to the PAMAM dendrimer conjugate. Anti-inflammatory and analgesic activities of the dendrimer conjugate
were found to be similar to those of the standard drug. Results of chronic ulceroginic activity showed deep ulceration and
high ulcer index for aceclofenac, whereas lower ulcer index was found for the PAMAM dendrimer and dextran (40 kDa) conjugates.
Experimental data suggest that PAMAM dendrimer and dextran (40 kDa) can be used as carriers for the sustained delivery of
aceclofenac along with a remarkable reduction in gastrointestinal toxicity. 相似文献
The results of photoconductivity (PC), photoluminescence (PL), optical absorption spectra, XRD and SEM studies are presented
for (Cd0.95-Pb0.05)S: CdCl2,Ce films prepared by chemical bath deposition technique. PC gains ∼107 are found in doped films. PL emission spectrum is found in red region which is related to 5d to 4f transition in Ce. Films prepared at 60°C show better PC while those prepared at room temperature (RT) show better PL. Optical
absorption studies show reduction in band gap due to addition of PbS. A peak due to Ce is also observed in absorption spectrum.
XRD studies show the presence of both CdS and PbS. SEM studies show presence of microcrystals, cluster of grains along with
some rod type structures. 相似文献
An amino‐acid‐based hydrophobically modified biocompatible copolymer, poly[(sodium N‐acryloyl‐L ‐valinate)‐co‐(N‐octylacrylamide)] was synthesized and characterized. Techniques such as fluorescence probes, DLS, and TEM were used to investigate its aggregation behavior in aqueous solution. The copolymer was observed to form micellar aggregates having diameters in the nanometer range in aqueous solution (pH = 8) through inter‐chain hydrophobic association. This behavior was found to be similar to that of poly[(sodium N‐acryloyl‐L ‐valinate)‐co‐(N‐dodecylacrylamide)]. The compact micellar nanostructures were observed to be stable with respect to changes of pH and temperature. The encapsulation and release of griseofulvin, a hydrophobic model drug, was studied.
In this paper we investigate Isotropic Multiresolution Analysis (IMRA), isotropic refinable functions, and wavelets. The main results are the characterization of IMRAs in terms of the Lax–Wiener Theorem, and the characterization of isotropic refinable functions in terms of the support of their Fourier transform. As an immediate consequence of these results, there are no compactly supported (in the space domain) isotropic refinable functions in many dimensions. Next we study the approximation properties of IMRAs. Finally, we discuss the application of IMRA wavelets to 2D and 3D-texture segmentation in natural and biomedical images. 相似文献