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81.
Donggen Zhou Siguang Li Jian Wen Xi Gong Ling Xu Yuping Luo 《Computational Biology and Chemistry》2008,32(1):61-66
By computational analyses, we identified 357 miRNA candidates from Canis familiaris genome, among which 300 are homology of characterized human miRNAs, the remains are not reported in any other animal. Of the 357 miRNA genes, 142 are organized into 53 clusters, and two clusters locate in the paternally imprinted region. These dog miRNAs may regulate more than 800 possible targets, which are involved in a wide range of cellular processes. Remarkably, miR-186 resides in the eighth intron of its target gene in the same orientation, suggesting a feedback regulation of miRNA on its host gene. 相似文献
82.
Kangkan Sarmah Amlan J. Kalita Ankur K. Guha 《International journal of quantum chemistry》2023,123(1):e27006
Attachment of one electron to 1,2-diBeX-benzene and 1,2-diZnX-benzene derivatives leads to the formation of stronger Be Be and Zn Zn interaction compared to the neutral one. This is reflected in the dramatic shortening of the Be Be and Zn Zn distance. The formation of these 2-center-1-electron bonds have also been confirmed by topological survey of electron density using quantum theory of atoms in molecules and electron localization function. The formation of these bonds is expected to render stability to these radical anions. These radical anions are stable toward electron detachment and computed bond dissociation energy values are also significant. 相似文献
83.
Amlan J. Kalita Namrata Gohain Abhik Bordoloi Dr. Kusum K. Bania Dr. Ankur K. Guha 《Chemphyschem》2023,24(9):e202200873
Number of bonds formed by sharing an electron pair between two atoms is not restricted to one, it can go beyond four and six is the maximum. While homopolar sextuple bond in Mo2 and W2 has been reported, such a high bond order in heteropolar diatomics has remained elusive. In the pursuit of the sextuple bond in polar diatomics, the present study depicts the existence of such multiple bonds in Rhodium-Scandium hetero-diatom based on relativistic quantum chemical calculations. The bonding comprises of three normal electron sharing covalent bonds and three dative covalent bonds. 相似文献
84.
Shamsipur M Dastjerdi LS Haghgoo S Armspach D Matt D Aboul-Enein HY 《Analytica chimica acta》2007,601(1):130-138
19F NMR spectroscopy was applied to the quantitative determination of fluoxetine enantiomers using different chiral recognition agents in pharmaceutical formulations. Several parameters affecting the enantioresolution including the type and concentration of chiral selector, concentration of fluoxetine and temperature were studied. The chiral selectors investigated are the cyclic oligosaccharides α-, β- and γ-cyclodextrin and a diamino derivative of methylated α-cyclodextrin (DAM-α-CD), linear polysaccharides (maltodextrin with dextrose equivalents of 4.0-7.0, 13.0-17.0 and 16.5-19.5) and the macrocyclic antibiotic vancomycin. Among the chiral selectors used, DAM-α-CD turned out to give the best resolution of the 19F NMR signals of (R)- and (S)-fluoxetine. The calibration curve was linear for (R)- and (S)-fluoxetine over the range 0.10-1.35 mg mL−1, the detection limits (S/N = 3) being 5.9 and 7.5 μg mL−1 for the pure solutions of (R)- and (S)-fluoxetine, respectively. The recovery studies performed on pharmaceutical samples ranged from about 90 to 110% with relative standard deviations of <8%. The results showed that the proposed method is rapid, precise and accurate. Applying statistical Student's t-test revealed insignificant difference between the real and measured contents at the 95% confidence level. 相似文献
85.
Xing YH Zhang XJ Sun Z Han J Zhang YH Zhang BL Ge MF Niu SY 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,68(5):1256-1262
A series of Cu(II) complexes Cu(2)[micro-pz](2)[HB(pz)(3)](2) (1), Cu[H(2)B(pz)(2)](2) (2), Cu[HB(pz)(3)](2) (3), Cu[HB(pz(Me2))(3)](2) (4), Cu[B(pz)(4)](2) (5) (pz=pyrazole), have been synthesized and characterized by elemental analysis, IR, UV-vis, X-ray diffraction, thermal analysis and theoretical analysis. The IR spectra give the Cu-N vibration modes at 322, 366, 344, 387, and 380 cm(-1) in complexes 1-5, respectively. The UV spectra show all the complexes have same UV absorption at 232 nm; there is another band at 332 nm for complexes 1, 2 and 4, while for complexes 3 and 5, the bands are at 272 and 308 nm, respectively. Complex 1 has a binuclear structure in which two pyrazole ligands bridge two Cu-Tp units. In 2-5, the Cu(II) centers are coordinated with dihydrobis(pyrazolyl)borate (Bp), hydrotris(pyrazolyl)borate (Tp), hydrotris(3,5-Me2pyrazolyl)borate (Tp'), tetrakis(pyrazolyl)borate (Tkp) respectively to form a mononuclear structure. The results of thermal analysis for complexes 1-5 are discussed too. 相似文献
86.
A Bayesian statistical approach is introduced to assess experimental data from the analyses of radionuclide activity concentration in environmental samples (low activities). A theoretical model has been developed that allows the use of known prior information about the value of the measurand (activity), together with the experimental value determined through the measurement. The model has been applied to data of the Inter-laboratory Proficiency Test organised periodically among Spanish environmental radioactivity laboratories that are producing the radiochemical results for the Spanish radioactive monitoring network. A global improvement of laboratories performance is produced when this prior information is taken into account. The prior information used in this methodology is an interval within which the activity is known to be contained, but it could be extended to any other experimental quantity with a different type of prior information available. 相似文献
87.
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89.
高层轻板框架结构中的相互作用分析 总被引:1,自引:0,他引:1
本文对高层轻板框架中的相互作用进行了分析。讨论了复合板中填充块的等效斜压杆的有效宽度及其影响因素,以此所得桁架计算模型的计算结果与实测结果比较接近。在此基础上给出轻板框轲结构在弹性阶段按剪方法和弹塑性阶段框架--桁架的计算模型。 相似文献
90.