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111.
Deng B Wang Z Song J Xiao Y Chen D Huang J 《Analytical and bioanalytical chemistry》2011,401(7):2143-2152
The doxorubicin (DOX) uptake in single human leukemia K562 cells with changes in both drug dosage and exposure period was
studied using capillary electrophoresis (CE) coupled with laser-induced fluorescence (LIF) detection. The cells were treated
with DOX at different concentrations (1, 3, 10, 20, 30, and 50 μM) and for different exposure times (1, 3, 5, 24, and 48 h).
At least 20 cells were analyzed for each DOX-treated cell population. A marked heterogeneity in DOX uptake among single cells
was observed, because the relative standard deviation of the uptake of DOX by single cells ranged from 24.0% to 61.1% within
each cell population. The cell-to-cell heterogeneity in DOX uptake first decreased and then became constant with increasing
drug concentration, but it did not exhibit regular variation with increasing exposure time. The mean DOX uptake was a linear
function of drug concentration (r ≥ 0.9667). In terms of the correlation with exposure time, the mean DOX uptake reached its maximum at 3 h for the cell populations
treated with 1–10 μM DOX, while it kept increasing during 48 h exposure of cell populations to 20–50 μM DOX. Because it eliminates
DOX fluorescence quenching and sample loss, the CE-LIF method directly detects the true DOX uptake by single cells, and thus
presents accurate information on both the cell-to-cell heterogeneity in DOX uptake and the patterns of DOX uptake in K562
cells as functions of drug concentration and exposure time. 相似文献
112.
Dan Ben-Yaakov David Andelman Rudi Podgornik Daniel Harries 《Current Opinion in Colloid & Interface Science》2011,16(6):542-550
In aqueous solutions, dissolved ions interact strongly with the surrounding water and surfaces, thereby modifying solution properties in an ion-specific manner. These ion-hydration interactions can be accounted for theoretically on a mean-field level by including phenomenological terms in the free energy that correspond to the most dominant ion-specific interactions. Minimizing this free energy leads to modified Poisson-Boltzmann equations with appropriate boundary conditions. Here, we review how this strategy has been used to predict some of the ways ion-specific effects can modify the forces acting within and between charged interfaces immersed in salt solutions. 相似文献
113.
Dan Tian SuiJun Liu DaShuai Zhang Ze Chang TongLiang Hu XianHe Bu 《中国科学:化学(英文版)》2013,56(12):1693-1700
Three new cobalt complexes, {[Co5(tci)2(bimb)3(µ3-O)2(H2O)2]·3DMF·4H2O} n (1), {[Co3(tci)2(bib)]·2DMF·2H2O} n (2) and {[Co(Htci)(bpea)0.5]·H2O} n (3) (H3tci = tris(2-carboxyethyl)isocyanurate, bimb = 4,4′-bis(imidazol-1-yl)biphenyl, bib = 1,4-bis(imidazol-1-yl)benzene, bpea = 1,2-bis(4-pyridyl)ethane, DMF = N,N′-dimethylformamide), have been successfully synthesized through the assembly of Co(II) ions, H3tci and different N-donor ligands, respectively. All complexes were structurally characterized by single crystal X-ray diffraction, elemental analyses, IR spectra, thermogravimetric (TG) analyses and X-ray powder diffraction (XRPD). Complex 1 exhibits a 3D three-fold parallel interpenetrated 3D → 3D structure with (65·8) CdSO4 topology. Complex 2 is built from [Co3(µ2-Ocarboxyl)2(CO2)4] clusters and linear bib ligands, displaying a two-fold parallel interpenetrated (3,8)-connected (43)2(46·618·84) topology, while complex 3 is a 3D pillar-layered structure involving an infinite -Co-(µ2-Ocarboxyl)(CO2)-Co-chain. The diverse structures of the three complexes indicate that the skeletons of different N-donor ligands play an important role in the assembly of such different frameworks. In addition, magnetic investigation indicates that besides spin-orbit coupling of Co(II) ions, there exist antiferromagnetic exchange interactions in Co5 and Co3 clusters of 1 and 2, respectively. 相似文献
114.
Sorin Mager Ionel Hopârtean Dan Bini§or 《Monatshefte für Chemie / Chemical Monthly》1978,109(6):1393-1401
The spectra of some 9-chloro-6-nitroacridines with methoxy substituents in position 1,4; 2,4; 3,4; 2,3; and ethoxy substituents in positions 1, 2, 3, were recorded. The influence of electron releasing alkoxy groups and electron withdrawing nitro groups on chemical shifts of protons in the 9-chloroacridinic cycle was discussed and PMR parameters were determined, comparatively with those of acridine and 9-chloroacridine. Good agreement between calculated and experimental values is observed. The spectrum of 9-chloro-1,2,3-triethoxyacridine shows for the four protons of the ringC. (H-5, H-6, H-7, H-8) anAMNX coupling pattern whose parameters were determined. 相似文献
115.
Baocai Du Renyong Geng Wenliang Tan Yuchao Mao Donghui Li Xue Zhang Dan Liu Weihua Tang Wenchao Huang Tao Wang 《Journal of Energy Chemistry》2021,(3):131-137
Molecular ordering within the photoactive layer plays a crucial role in determining the device performance of organic solar cells(OSCs).However,the simultaneous molecular ordering processes of polymer donors and non-fullerene acceptors(NFAs)during solution casting usually bring confinement effect,leading to insufficient structural order of photovoltaic components.Herein,the molecular packing of mINPOIC NFA is effectively formed through a heating induced aggregation strategy,with the aggregation of PBDB-T,which has a strong temperature dependence,is retarded by casting on a preheated substrate to reduce its interference toward m-INPOIC.A sequent thermal annealing treatment is then applied to promote the ordering of PBDB-T and achieve balanced aggregation of both donors and acceptors,resulting in the achievement of a maximum efficiency of 13.9% of PBDB-T:m-INPOIC binary OSCs.This work disentangles the interactions of donor polymer and NFA during the solution casting process and develops a rational strategy to enhance the molecular packing of NFAs to boost device performance. 相似文献
116.
Several imidazo[4,5-d]pyridazine nucleosides which are structurally similar to inosine were synthesized. Anhydrous stannic chloride-catalyzed condensation of persilylated imidazo[4,5-d]-pyridazin-4(5H)one (1) and imidazo[4,5-d]pyridazine-4,7(5H,6H)dione ( 16 ) with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose ( 3 ) provided (after sodium methoxide deblocking) 6-β-D-ribo furanosylimidazo[4,5-d]pyridazin-4(5H)one (5) and 3,6-di-(β-D-ribofuranosyI)imidazo[4,5-d]pyridazin-4-one ( 7 ); and 1-(β-D-ribofuranosyl)imidazo[4,5-d]pyridazine-4,7(5H,6H)dione ( 19 ) and 1,5 or 6-di-(β-D-ribofuranosyl)imidazo[4,5-d ]pyridazine-4,7(5H or 6H)dione ( 21 ), respeeitvely. 4,7-Diehloro-1-β-D-ribofuranosylimidazo[4,5-d]pyridazine ( 12 ) and dimethyl 1-β-D-ribofuranosylimidazole-4,5-dicarboxylate ( 26 ), both prepared from stannic chloride-catalyzed ribosylations of the corresponding heterocycles, were converted in several steps to 3-β-D-ribo-furanosy limidazo[4,5-d]pyridazin-4(5H)one ( 14 ) and nucleosidc 19 , respectively. Acid-catalyzed isopropylidenation of mesomeric betaine 7 or nuclcoside 14 provided 3-(2,3-isopropylidene-β-D-ribofuranosyl)imidazo[4,5-d]pyrizin-4(5H)one ( 31 ). 1-β-D-Ribofuranosylimidazo[4,5-d]-pyridazine ( 29 ) was obtained in several steps from nueleoside 12 . The structure of the nucleosides was established by the use of carbon-13 and proton nmr. 相似文献
117.
Ying Liu Ying‐Hui Yu Yi‐Fu Liu Guang‐Feng Hou Xiao‐Dan Wang Bo Wen Jin‐Sheng Gao 《无机化学与普通化学杂志》2013,639(1):193-196
The cage‐like complex, Ag4L4(NO3)4 ( 1 ) [L = 1, 4‐bis(pyridine‐2‐ylmethoxy)benzene] was synthesized by the reaction of the flexible bidentate ligand and silver nitrate. It was characterized by elemental analysis, IR spectroscopy, TG, and single‐crystal X‐ray analysis. Complex 1 is reported as the first cage‐like cluster constructed by four nitrate anions bridging two [2+2] macrocycles. A blue luminescent emission and luminescent enhancement effect are observed in complex 1 . 相似文献
118.
Dr. A. Pernille Tofteng Dr. Søren L. Pedersen Prof. Dan Staerk Prof. Knud J. Jensen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(29):9024-9031
Precise microwave heating has changed the way many small molecules are being synthesized and, currently, the field of solid‐phase peptide synthesis is undergoing dramatic changes owing to the use of microwave heating. To fully reap the benefits of precise microwave heating for the formation of amide bonds in peptide synthesis, it is important to understand the kinetics of formation and break‐down of activated esters and their N‐acylation of the nascent peptide chain at elevated temperatures. Herein, we present systematic studies of, first, the rate of formation of activated esters by NMR spectroscopy and, second, their N‐acylation during peptide synthesis. A study of the amount of residual water in the solvents revealed a significant effect on electrophilic reagents and intermediates. This observation was expanded into a general study of microwave heating in peptide synthesis. 相似文献
119.
Jin‐Yun Wang Chen‐Sheng Lin Min‐Yi Zhang Guo‐Liang Chai Wen‐Dan Cheng 《International journal of quantum chemistry》2012,112(3):759-769
Geometrical structures of the investigated endohedral metallofullerenes Sc3N@C2n (2n = 68, 70, 78, and 80) were optimized at the B3LYP/6‐31G* level. The analyses of electronic structures display that the contribution of fullerene cage to the lowest unoccupied molecular orbital decreases as the cage size increases. Based on the optimized structures, the time‐dependent density functional theory combined with the sum‐over‐states method was used to investigate their nonlinear optical properties. Calculated third‐order polarizabilities γ and two‐photon absorption (TPA) cross‐section δ do not present the monotone variation with the size of fullerene cage, with largest γ of 0.48 × 10?34 esu for Sc3N@C78 in static state, and largest δ of 12.374 GM for Sc3N@C70 in the wavelength of 902.5 nm. However, the obtained TPA resonant peaks shift red with the size of fullerene cage. By analyzing the electronic origin of the third‐order optical properties, it is found that the charge transfers from the fullerene cage to the encapsulated Sc3N cluster make important contributions to the studied properties. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
120.
Muyi He You Jiang Dan Guo Xingchuang Xiong Xiang Fang Wei Xu 《Journal of the American Society for Mass Spectrometry》2017,28(7):1262-1270
A dual-polarity linear ion trap (LIT) mass spectrometer was developed in this study, and the method for simultaneously controlling and detecting cations and anions was proposed and realized in the LIT. With the application of an additional dipolar DC field on the ejection electrodes of an LIT, dual-polarity mass spectra could be obtained, which include both the mass-to-charge (m/z) ratio and charge polarity information of an ion. Compared with conventional method, the ion ejection and detection efficiency could also be improved by about one-fold. Furthermore, ion–ion reactions within the LIT could be dynamically controlled and monitored by manipulating the distributions of ions with opposite charge polarities. This method was then used to control and study the reaction kinetics of ion–ion reactions, including electron transfer dissociation (ETD) and charge inversion reactions. A dual-polarity collision-induced dissociation (CID) experiment was proposed and performed to enhance the sequence coverage of a peptide ion. Ion trajectory simulations were also carried out for concept validation and system optimization. 相似文献