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971.
972.
Congke Zheng Xiaohui Zhang Muhammad Ijaz Hussain Mingming Huang Qing Liu Yan Xiong Xiangming Zhu 《Tetrahedron letters》2017,58(6):574-577
An approach to the dichlorinative deamidation of primary β-ketoamides through ketonic cleavage is described, and a series of α,α-dichloroketones were furnished mostly in the presence of TEMPO. Based on control experiments, a mechanism involving tandem dichlorination and deamidation is proposed to interpret the observed reactivity. 相似文献
973.
Khan Sharjeel Ahmed Zulfiqar Usama Hussain Syed Zajif Zaheer Usama Hussain Irshad Husain Syed Wilayat Subhani Tayyab 《Journal of Sol-Gel Science and Technology》2017,81(3):912-920
Journal of Sol-Gel Science and Technology - We demonstrate the synthesis of hydrophobic silica nanoparticles from sodium silicate and their application in separation of the oil–water mixture.... 相似文献
974.
Russian Journal of General Chemistry - Naked-eye colored chemo dosimeters based on symmetrical calix[4]azo dye conjugates A1–3 are synthesized and characterized. Calix[4]azo dye conjugates... 相似文献
975.
Tariq Hussain Ahmed Shoukat Ahmad Adnan Hassan Muhammad Anwar Muhammad 《Journal of Thermal Analysis and Calorimetry》2019,136(5):2171-2182
Journal of Thermal Analysis and Calorimetry - We investigated the thermal performance of micro-hole cellular structure using Al2O3–H2O and CuO–H2O nanofluids with 0.67% and 0.4%,... 相似文献
976.
Hao Zhao Dr. Sameer Hussain Xiaoyan Liu Shengliang Li Dr. Fengting Lv Dr. Libing Liu Prof. Shu Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(42):9834-9839
Introduction of chirality into a supramolecular self-assembly system plays an indispensable role in attaining specific molecular recognition ability. Herein, a chiral anticancer drug 5′-deoxy-5-fluorouridine (5′DFU) was explored for inducing the self-assembly of a cationic perylene diimide derivative containing boronic acid groups (PDI-PBA) into a highly ordered right-handed helical structure. As a result, PDI-PBA exhibited a molecular recognition ability towards 5′DFU among other cis-diols and anticancer drugs. With the help of a dynamic covalent bond and favorable hydrogen-bonding interactions, chirality transfer from chiral 5′DFU to achiral PDI-PBA breaks down the strong π–π stacking of PDI-PBA and makes it reorganize into highly ordered helical supramolecular structures. This work provides an insight into chiral anticancer drug tuning interactions of π-chromophores and the inducement of hierarchical self-assembly to achieve specific molecular recognition. 相似文献
977.
Mushraf Hussain Maria Taddei Dr. Laura Bussotti Prof. Paolo Foggi Prof. Jianzhang Zhao Prof. Qingyun Liu Dr. Mariangela Di Donato 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(68):15615-15627
Oxoverdazyl (Vz) radical units were covalently linked to the naphthalenediimide (NDI) chromophore to study the effect of the radical on the photophysical properties, especially the radical enhanced intersystem crossing (REISC), which is a promising approach to develop heavy-atom-free triplet photosensitizers. Rigid phenyl or ethynylphenyl linkers between the two moieties were used, thus REISC and formation of doublet (D1, total spin quantum number S=1/2) and quartet states (Q1, S=3/2) are anticipated. The photophysical properties of the dyads were studied with steady-state and femtosecond/nanosecond transient absorption (TA) spectroscopies and DFT computations. Femtosecond transient absorption spectra show a fast electron transfer (<150 fs), and ISC (ca. 1.4–1.85 ps) is induced by charge recombination (CR, in toluene). Nanosecond transient absorption spectra demonstrated a biexponential decay of the triplet state of the NDI moiety. The fast component (lifetime: 50 ns; population ratio: 80 %) is assigned to the D1→D0 decay, and the slow decay component (2.0 μs; 20 %) to the Q1→D0 ISC. DFT computations indicated ferromagnetic interactions between the radical and chromophore (J=0.07–0.13 eV). Reversible formation of the radical anion of the NDI moiety by photoreduction of the radical-NDI dyads in the presence of sacrificial electron donor triethanolamine (TEOA) is achieved. This work is useful for design of new triplet photosensitizers based on the REISC effect. 相似文献
978.
In this paper, we have completely classified the locally rotationally symmetric(LRS) Bianchi Type Ⅰ spacetimes via Noether symmetries(NS). The usual Lagrangian corresponding to LRS Bianchi Type Ⅰ metric is used to find the set of determining equations. To achieve a complete classification, these determining equations are generally integrated to find the components of NS vector field and the metric coefficients. During this procedure, several cases arise which give different Noether algebras of dimension 5,..., 9, 11, and 17. A comparison is established between the obtained NS and the Killing and homothetic vectors. Corresponding to all NS generators, the conservation laws are stated by using Noether's theorem. The metrics which we have obtained as a result of our classification are shown to be anisotropic or perfect fluids which satisfy certain energy conditions. 相似文献
979.
Banashree Deka Arnab Bhattacharyya Sanjoy Mukherjee Tukki Sarkar Kiran Soni Samya Banerjee Kandarpa K. Saikia Sasanka Deka Akhtar Hussain 《应用有机金属化学》2018,32(4)
Six novel mixed‐ligand copper(II) complexes, namely, [Cu(R‐tpy)(L)]NO3 ( 1–6 ), where R‐tpy is 4′‐phenyl‐2,2′:6′,2′′‐terpyridine (Ph‐tpy; 1–3 ) and 4′‐ferrocenyl‐2,2′:6′,2′′‐terpyridine (Fc‐tpy; 4–6 ), L is the bidentate O,O donor monoanion of plumbagin (5‐hydroxy‐2‐methyl‐1,4‐naphthoquinone; plum in 1 , 4 ), chrysin (5,7‐dihydroxyflavone; chry in 2 , 5 ) and curcumin (bis(4‐hydroxy‐3‐methoxyphenyl)‐1,6‐diene‐3,5‐dione; curc in 3 , 6 ) have been synthesized and characterized and their in vitro cytotoxicity against cancer cells is evaluated. The energy optimized structures and the frontier orbitals of the complexes have been obtained from the DFT calculations. Complexes 4–6 with a conjugated ferrocenyl moiety and TCM anticancer ligands, namely, plum (in 4 ), chry (in 5 ) and curc (in 6 ) showed potent cytotoxicity giving respective IC50 values of 1.2 μM, 0.62 μM and 0.21 μM in HeLa and 2.0 μM and 1.0 μM and 0.34 μM in MCF‐7 cancer cells while being much less toxic to MCF‐10A normal cells (IC50: 8.3‐17.1 μM). In contrast, complexes 1–3 with a conjugated phenyl moiety were appreciably less toxic to HeLa cells with respective IC50 values of 10.4 μM, 8.1 μM and 5.5 μM when compared with their ferrocenyl analogues 4–6 . Mechanistic studies using Hoechst staining and Annexin‐V‐FITC assays on cancer cells revealed an apoptotic pathway of cell death induced by the complexes. Fluorescence imaging study showed that complex 6 having curcumin as ligand localized primarily in the mitochondria of HeLa cells. Thus, we demonstrate in this study that ferrocene conjugation to copper(II) complexes of TCM anticancer ligands significantly increases the selectivity and cytotoxicity of the resulting complexes towards cancer cells over normal cells. 相似文献
980.