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81.
Following recent studies concerning the use of information theory in electronic structure theory of atomic and molecular systems, an analytical relationship between Onicescu information energy and densities of Shannon entropy and the two forms of the Fisher information has been presented. The established proof must be viewed in the light of the exponentially decaying nature of the asymptotic density of atoms and molecules. 相似文献
82.
A new tetracyclic triterpenoid zeeshanol [25,26,27-trinor-apotirucalla-(apoeupha)-6alpha-, 21-dihydroxy, 7alpha-acetoxy, 1,14,22-tri-en-3, 16-dione] (1) along with a known constituent desfurano-6alpha-hydroxyazadiradione (2) have been isolated from the methanolic extract of the leaves of Azadirachta indica. The structure and the relative configurations of 1 were determined by the spectroscopic method (1H- and 13C-NMR, IR, and MS) and 2D-NMR experiments. 相似文献
83.
Afshan Sadiq 《Central European Journal of Mathematics》2010,8(6):1156-1159
In this short note, we extend Faugére’s F4-algorithm for computing Gröbner bases to polynomial rings with coefficients in an Euclidean ring. Instead of successively reducing single S-polynomials as in Buchberger’s algorithm, the F4-algorithm is based on the simultaneous reduction of several polynomials. 相似文献
84.
Choudhary MI Begum A Abbaskhan A Ajaz A Shafique-ur-Rehman Atta-ur-Rahman 《Chemical & pharmaceutical bulletin》2005,53(11):1469-1471
A phytochemical investigation on the aerial parts of Lindelofia stylosa has resulted in the isolation of seven phenyl propanoids. This includes three analogs of lithospermic acid, along with rosmarinic acid and its ester derivatives. Compound 1 was identified as a new natural product. These compounds were studied for their antioxidant properties. 相似文献
85.
Fawaz Alasmari Sary Alsanea Assim A. Alfadda Ibrahim O. Alanazi Mohthash Musambil Afshan Masood Faleh Alqahtani Omer I. Fantoukh Abdullah F. Alasmari Hicham Benabdelkamel 《Molecules (Basel, Switzerland)》2021,26(17)
Cannabis use has been growing recently and it is legally consumed in many countries. Cannabis has a variety of phytochemicals including cannabinoids, which might impair the peripheral systems responses affecting inflammatory and immunological pathways. However, the exact signaling pathways that induce these effects need further understanding. The objective of this study is to investigate the serum proteomic profiling in patients diagnosed with cannabis use disorder (CUD) as compared with healthy control subjects. The novelty of our study is to highlight the differentially changes proteins in the serum of CUD patients. Certain proteins can be targeted in the future to attenuate the toxicological effects of cannabis. Blood samples were collected from 20 male individuals: 10 healthy controls and 10 CUD patients. An untargeted proteomic technique employing two-dimensional difference in gel electrophoresis coupled with mass spectrometry was employed in this study to assess the differentially expressed proteins. The proteomic analysis identified a total of 121 proteins that showed significant changes in protein expression between CUD patients (experimental group) and healthy individuals (control group). For instance, the serum expression of inactive tyrosine protein kinase PEAK1 and tumor necrosis factor alpha-induced protein 3 were increased in CUD group. In contrast, the serum expression of transthyretin and serotransferrin were reduced in CUD group. Among these proteins, 55 proteins were significantly upregulated and 66 proteins significantly downregulated in CUD patients as compared with healthy control group. Ingenuity pathway analysis (IPA) found that these differentially expressed proteins are linked to p38MAPK, interleukin 12 complex, nuclear factor-κB, and other signaling pathways. Our work indicates that the differentially expressed serum proteins between CUD and control groups are correlated to liver X receptor/retinoid X receptor (RXR), farnesoid X receptor/RXR activation, and acute phase response signaling. 相似文献
86.
Tetracyclic triterpenoids from the leaves of Azadirachta indica and their insecticidal activities 总被引:1,自引:0,他引:1
Siddiqui BS Afshan F Gulzar T Sultana R Naqvi SN Tariq RM 《Chemical & pharmaceutical bulletin》2003,51(4):415-417
A new tetranortriterpenoid, meliatetraolenone [24,25,26,27-tetranor-apotirucalla-(apoeupha)-6alpha-O-methyl, 7alpha-senecioyl(7-deacetyl)-11alpha,12alpha,21,23-tetrahydroxy-21,23-epoxy-2,14,20(22)-trien-1,16-dione] (1) was isolated from the methanolic extract of fresh leaves of Azadirachta indica along with the known compound odoratone (3) which was hitherto unreported from this source. Their structures have been elucidated by spectral studies including 2D NMR. The insecticidal activities of 1 as well as those of odoratone (3) are reported. 1 and odoratone both showed mortality on fourth instar larvae of mosquitoes (Anopheles stephensi) with LC(50) values of 16 and 154 ppm, respectively. 相似文献
87.
Gul-E-Noor F Jee B Pöppl A Hartmann M Himsl D Bertmer M 《Physical chemistry chemical physics : PCCP》2011,13(17):7783-7788
The process of water adsorption on a dehydrated Cu(3)(BTC)(2) (copper (II) benzene 1,3,5-tricarboxylate) metal-organic framework (MOF) was studied with (1)H and (13)C solid-state NMR. Different relative amounts of water (0.5, 0.75, 1, 1.5, 2, and 5 mole equivalents with respect to copper) were adsorbed via the gas phase. (1)H and (13)C MAS NMR spectra of dehydrated and water-loaded Cu(3)(BTC)(2) samples gave evidence on the structural changes due to water adsorption within the MOF material as well as information on water dynamics. The analysis of (1)H spinning sideband intensities reveals differences in the (1)H-(63/65)Cu hyperfine coupling between dehydrated and water-loaded samples. The investigation was continued for 60 days to follow the stability of the Cu(3)(BTC)(2) network under humid conditions. NMR data reveal that Cu(3)(BTC)(2) decomposes quite fast with the decomposition being different for different water contents. 相似文献
88.
The interactions between eight amino acid based anions and four imidazolium-based cations have been investigated by density functional theory. The electronic and structural properties of the resulting amino acid ionic liquids (AAILs) have been unveiled by means of the atoms in molecules framework. The calculated interaction energy was found to increase in magnitude with decreasing alkyl chain length at imidazolium ring. Moreover, AAILs composed of an amino acid with some functional group such as aromatic ring had decreased interaction energy. Finally, several correlative relationships between glass transition temperature and interaction energy as well as density at bond critical point have been checked for 1-ethyl-3-methylimidazolium based ILs. Although the obtained correlations do not show excellent fits, a preliminary estimation of the glass transition temperature of different AAILs can be achieved by use of their electronic properties. 相似文献
89.
The theoretical determination of electric response properties of the biological systems is a field where the application of density functional theory (DFT) appears to be quite promising. In this work, the performance of 41 density functional methods is evaluated in predicting dynamic polarizabilities of an experimental benchmark set of 20 proteinogenic amino acids. The behavior of a large number of density functionals, including various types of the local spin density approximation (LSDA), generalized gradient approximation (GGA), meta‐GGA (m‐GGA), hybrid‐GGA (h‐GGA), hybrid meta‐GGA (hm‐GGA), and range‐separated hybrid‐GGA (rsh‐GGA), has been assessed for the purpose. Analyzing the results of our DFT benchmarking, we found that these computationally economical methods show very diverse predictive capability and a careful selection of DFT functionals is very important in the polarizability calculations. Considering the role of exchange, correlation, dispersion and long‐range corrections, it turned out that in the LSDA class, SVWN3 gives better results than SPL and SVWN5 toward the reference values. Of the GGA methods, OPBE outperforms all other functionals. The M06‐L is the best method of m‐GGA class. The B3LYP and TPSSh are the best functionals of h‐GGA and hm‐GGA lineages, respectively. Finally, CAM‐B3LYP is the best method of rsh‐GGA functionals that predicts the most accurate polarizability for amino acids by a large margin with respect to others. Overall, the best performing functionals turn out to be hm‐GGAs TPSSh, TPSS1KCIS, M05, tau‐HCTHhyb, and h‐GGA B3LYP. Hopefully, the results of this investigation might provide the useful guidance to propose a new exchange‐correlation functional for calculating the optical properties of biomolecular materials. © 2013 Wiley Periodicals, Inc. 相似文献
90.
New Azothiacalix[4]arenes Containing Biheterocyclic Subunits: Extraction and Complexation Properties
New thiacalix[4]arenes 2a, 3a, 4 and 5 functionalized with biheterocyclic and azophenyl groups at the lower rim and the upper rim of the macrocycle, respectively, were synthesized and their extraction properties towards Cu2+, Ag+, Ni2+ and Pb2+ studied. The complexation properties of the bithiazolyl receptors 2a, 4 and the bipyridyl receptors 3a, 5 were investigated by fluorescence and UV–visible titrations, respectively. The stoichiometries of the complexes were determined. A stoichiometry of 1:1 was found for the Cu-2a, Ag-3a complexes and 2:1 for the Cu2-4, Ag2-5 complexes as a function of the number of grafted bithiazolyl groups. The association constants for the 1:1 complexes were calculated using the Benesi–Hildebrand plot and by linear regression analysis. 相似文献