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1.
Ezzat Hany G. Bayoumi Ashraf H. Sherbiny Farag F. El-Morsy Ahmed M. Ghiaty Adel Alswah Mohamed Abulkhair Hamada S. 《Molecular diversity》2021,25(1):291-306
Molecular Diversity - Many shreds of evidence have recently correlated A2B receptor antagonism with anticancer activity. Hence, the search for an efficient A2B antagonist may help in the... 相似文献
2.
Maha M. Abdelrahman Neven M. Habib Aml A. Emam Hamada M. Mahmoud Nada S. Abdelwhab 《Biomedical chromatography : BMC》2020,34(4):e4804
Green TLC-densitometric and RP-HPLC methods were developed and validated for the determination of the active prodrug sulfasalazine (SZ), its active metabolite mesalazine (MZ) and the major active metabolite of mesalazine, N-acetyl-5-aminosalicylic acid (AS). In the developed TLC-densitometric method, chromatographic separation was carried out on TLC silica gel plates 60 F254 using a developing system consisting of ethyl acetate–methanol–ammonia solution 33% (8:2.5:0.3, by volume) and then scanning the separated bands at 215 nm using hydrochlorothiazide as an internal standard with linearity ranges of 0.4–3, 0.4–2.4 and 0.3–2 for SZ, MZ and AS, respectively. The developed RP-HPLC method depended on chromatographic separation using a C18 column with a solvent mixture of methanol–aqueous acetic acid solution (pH 5) as a mobile phase with gradient elution mode and UV scanning at 243 nm using pyrazinamide as internal standard with linearity ranges of 5–50, 5–40, and 3–20 for SZ, MZ and AS, respectively. US Food and Drug Administration guidelines were followed during validation of the methods. The greenness of the developed methods was estimated using the greenness profile and the Eco-Scale approach. Both methods passed the four quadrants of the greenness profile and had Eco-Scale score ˃75, thus they were considered to be green according to these approaches. 相似文献
3.
Marzhan Nassurlla N. Burtebayev T. Kh. Sadykov I. Boztosun N. Amangeldi D. Alimov Zh. Kerimkulov J. Burtebayeva Maulen Nassurlla A. Kurakhmedov S.B. Sakuta Mesut Karakoc Awad A. Ibraheem K.W. Kemper Sh. Hamada 《中国物理C(英文版)》2020,44(10):104103-104103-9
The angular distributions of elastic scattering of 14N ions on 10B targets have been measured at incident beam energies of 21.0 and 24.5 MeV. Angular distributions at higher energies 38–94.0 MeV (previously measured) were also included in the analysis. All data were analyzed within the framework of the optical model and the distorted waves Born approximation method. The observed rise in cross sections at large angles was interpreted as a possible contribution of the α-cluster exchange mechanism. Spectroscopic amplitudes SA2 and SA4 for the configuration 14N→ 10B +α were extracted. Their average values are 0.58±0.10 and 0.81±0.12 for SA2 and SA4, respectively, suggesting that the exchange mechanism is a major component of the elastic scattering for this system. The energy dependence of the depths for the real and imaginary potentials was found. 相似文献
4.
5.
Yasmen M. Moghazy Magda F. Fathalla Nagwa M. M. Hamada Yasser R. Elmarassi Ezzat A. Hamed 《国际化学动力学杂志》2020,52(5):341-355
Reactions of aniline derivatives in dimethyl sulfoxide with phenyl 1-(2,4-dinitronaphthyl) ether yield aryl 1-(2,4-dinitronaphthyl) amine, which results in substitution of the phenoxy groups at the naphthyl ipso carbon atom. Rate constants were measured spectrophotometrically, and reaction proton transfer was rate limiting. The values of the rate coefficients indicate a rate-limiting proton transfer mechanism with significant substituent effects. The calculated activation parameters were of regular variation with substituents in 4- and 3-position in the aniline nucleophile, and the reaction proceeded through a common mechanism. Hammett's reaction constant showed that the reaction rate constants depend on the electron density of the nitrogen atom of aniline derivative, whereas the coefficient value obtained from the Brönsted relation indicated that the reaction was significantly associative and quite zwitterion like. Computational studies of the substitution were carried out based on density functional theory, and theoretical to the experimental agreement was achieved. 相似文献
6.
Prof. Dr. Manabu Yamada Fumiya Uemura Dr. Uma Maheswara Rao Kunda Prof. Dr. Takenori Tanno Prof. Dr. Hiroshi Katagiri Prof. Dr. Fumio Hamada 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(38):8393-8399
Alkanes composed of C−C and C−H show a low electric polarization, and therefore, there is only very weak interaction between alkanes and adsorbents. Thus, it is difficult to separate a specific alkane from a mixture of alkanes by adsorption. Here, two activated “channel-like” crystals generated from brominated thiacalix[4]arene propyl ethers, which adopt 1,3-alternate and partial cone conformations, recognize specific alkane vapors depending on alkane-shape and -size, sorting in three-type alkane guests such as linear, branched, and cyclic alkanes. Two activated crystals, which are prepared by removal of solvent upon heating under reduced pressure, incorporate branched and/or cyclic alkane vapors by a unique “gate-opening” mechanism via a crystal transformation in the process. Linear alkane vapors do not trigger gate opening and are not taken up by the activated crystals. The shape and size molecular-recognition properties of the activated crystals promises considerable usefulness for the separation of linear, branched, and cyclic alkanes. 相似文献
7.
Prof. Dr. Tomoaki Tanase Dr. Kanako Nakamae Yume Okawa Mami Hamada Dr. Arimasa Matsumoto Prof. Dr. Takayuki Nakajima Prof. Dr. Takuya Nakashima Prof. Dr. Tsuyoshi Kawai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(8):e202104060
A P-stereogenic linear tetraphosphine tetraoxide, (R,R)- or (S,S)-dpmppm(=O)4, was synthesized to prepare C2 dinuclear M(hfa)3 complexes (M=Eu, Tb, Y) as the first example of lanthanide(III) complexes with P-chiral multidentate phosphine oxides. The mononuclear M(hfa)3 complexes (M=Eu, Y) with a P-chiral diphosphine dioxide, tpdpb(=O)2, were also prepared, and comparison of their photophysical properties for the EuIII complexes revealed that significant chiral induction from the P-chiral centers arises on the achiral M(hfa)3 units through intramolecular π-π stacking constraint in the dinuclear system. 相似文献
8.
Chin-Soon Phan Takashi Kamada Kazushi Kobayashi Toshiyuki Hamada 《Natural product research》2018,32(2):202-207
A new xenicane diterpenoid, 15-deoxy-isoxeniolide-A (1) along with four known compounds 9-deoxy-isoxeniolide-A (2), isoxeniolide-A (3), xeniolide-A (4) and coraxeniolide-B (5) were isolated from the Bornean soft coral Xenia sp. The structures of these metabolites were elucidated on the basis of spectral analysis, NMR and HRESIMS. Compound 5 showed cytotoxic activity against ATL cell line, S1T. 相似文献
9.
Chin-Soon Phan Takashi Kamada Takahiro Ishii Toshiyuki Hamada 《Natural product research》2019,33(6):808-813
One new compound, 12-epi-9-deacetoxyxenicin (1) along with a hydroperoxide product, 12-epi-9-deacetoxy-8-hydroperoxyxenicin (2) and two known sesquiterpenoids (3–4) were isolated from a population of Bornean soft coral Xenia sp. The structures of these secondary metabolites were elucidated based on their spectroscopic data. Compounds 1 and 2 showed cytotoxic activity against ATL cell line, S1T. In addition, compound 3 exhibited hyphal inhibition of Lagenidium thermophilum. 相似文献
10.
Measurements from instruments are sometimes censored at or below the instrument’s lower or upper limit of detection because the instruments have a calibrated response only over a certain data range. Near the ends of the range, the system reports a censored value such as “measurand value is less than threshold,” or “measurand value is more than threshold.” How should one analyze data that includes such “less than” and/or “more than” results and what is the impact of such censoring on estimation of variance components? To answer these two questions, this article makes three contributions: (1) It illustrates a straightforward numerical Bayesian analysis of such censored data based on the likelihood function, (2) it provides a simulation study to show the impact of increased amounts of censoring, and (3) it shows that if the true likelihood has an unknown form for measurand values near the threshold and another known form away from the threshold, then it is prudent for the measurement system to report censored values rather than actual values. Open source software to analyze censored data is provided as supplementary material. 相似文献