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171.
Kang-Chieh Lo Chiao-Yin Sun Yu-Ju Ding Jen-Ning Tsai Kai-Ping Chang Yi-En Wen Wan-Ling Chang Shin C. Chang Ming-Fu Chang Yun-Hsin Wang Yau-Hung Chen 《Research on Chemical Intermediates》2014,40(6):2177-2185
Benzo(a)pyrene is a chemical produced during the process of making fried, roasted, and smoked foods. It remains unclear whether benzo(a)pyrene affects the early development of human organs. In this study, we used the transgenic zebrafish line Tg(wt1b:GFP) as a model to assess benzo(a)pyrene-induced kidney malformation. By soaking zebrafish embryos in benzo(a)pyrene at various doses (2, 20, and 200 ppb), only a minor effect on the survival rate was detected (0 ppb: 97.8 ± 1.9 %; 2–200 ppb: 89.1 ± 5.8–91.5 ± 8.3 %). However, benzo(a)pyrene significantly affected the development of the kidney (malformation rates ranges from 50.0 ± 3.5 to 77.4 ± 5.3 %). Various abnormalities, such as unusual curving of pronephric tubes, swollen glomerulus, and incomplete development of pronephric ducts, were observed. This study provides a rapid and effective protocol for the evaluation of the notable effects of benzo(a)pyrene on embryonic kidney development. 相似文献
172.
Hongyu Zhang Changlong Hao Aihua Qu Maozhong Sun Liguang Xu Chuanlai Xu Hua Kuang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(18):7197-7204
The accumulation and deposition of β-amyloid (Aβ) plaques in the brain is considered a potential pathogenic mechanism underlying Alzheimer's disease (AD). Chiral l/d -FexCuySe nanoparticles (NPs) were fabricated that interfer with the self-assembly of Aβ42 monomers and trigger the Aβ42 fibrils in dense structures to become looser monomers under 808 nm near-infrared (NIR) illumination. d -FexCuySe NPs have a much higher affinity for Aβ42 fibrils than l -FexCuySe NPs and chiral Cu2−xSe NPs. The chiral FexCuySe NPs also generate more reactive oxygen species (ROS) than chiral Cu2−xSe NPs under NIR-light irradiation. In living MN9D cells, d -NPs attenuate the adhesion of Aβ42 to membranes and neuron loss after NIR treatment within 10 min without the photothermal effect. In-vivo experiments showed that d -FexCuySe NPs provide an efficient protection against neuronal damage induced by the deposition of Aβ42 and alleviate symptoms in a mouse model of AD, leading to the recovery of cognitive competence. 相似文献
173.
Chun-Dong Xue Zhong-Ping Sun Yong-Jiang Li Jian-Feng Chen Bo Liu Kai-Rong Qin 《Electrophoresis》2020,41(10-11):909-916
In the present study, we numerically demonstrate an approach for separation of micro and sub-micro diamagnetic particles in dual ferrofluid streams based on negative magnetophoresis. The dual streams are constructed by an intermediate sheath flow, after which the negative magnetophoretic force induced by an array of permanent magnets dominates the separation of diamagnetic particles. A simple and efficient numerical model is developed to calculate the motions of particles under the action of magnetic field and flow field. Effects of the average flow velocity, the ratio of sheath fluid flow to sample fluid flow, the number of the magnet pair as well as the position of magnet pair are investigated. The optimal parametric condition for complete separation is obtained through the parametric analysis, and the separation principle is further elucidated by the force analysis. The separation of smaller micro and sub-micro diamagnetic particles is finally demonstrated. This study provides an insight into the negative magnetophoretic phenomenon and guides the fabrication of feasible, low-cost diagnostic devices for sub-micro particle separation. 相似文献
174.
An efficient synthesis of 1,2-unsubstituted indolizines was developed via 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)–catalyzed decarboxylation reaction. A series of target products were successfully prepared with the tolerance of a variety of functional groups. This protocol features advantages such as easily available substrates, broad substituent scope, and eco-friendly conditions. 相似文献
175.
A catalytic enantioselective three-component Ugi reaction was developed. SPINOL-derived phosphoric acid with bulky 2,4,6-tricyclohexylphenyl groups at the 6,6′ positions was found to be the best catalyst to afford α-amino amide derivatives in good to excellent yields(62% to 99%) and enantiocontrol(81% to 99% enantiomeric excess). This asymmetric reaction was applicable well to an array of aliphatic aldehydes. The gram-scale synthesis, modification of dapsone, and enantioselective synthesis of(R)-Lacosamide underline the general utility of this methodology. Influence of dihedral angles and substituents of the chiral phosphoric acids on the enantioselectivity was also discussed in this article. 相似文献
176.
RNA-cleaving DNAzymes possess important roles in DNAzymes and have been widely used in the biosensors,DNA nanomachines owing to their ion-specific dependence.However,there are still challenges in constructing universal but versatile stimuli-responsive strategies of RNA-cleaving DNAzymes.Herein,a stimuli-responsive strategy for RNA-cleaving DNAzyme is proposed by the artful design of hairpin nanostructure,in which the activities of DNAzyme(Pb~(2+) -dependent DNAzyme as a model) in the hairpin's loop are p H-regulated by using the triplex stem as the "lock".Upon introducing the "key",p H values,the DNAzyme will be activated and fragment the substrate of it in the presence of Pb~(2+),accompanied by the turn-on of the fluorescence quenched by fluorescence resonance energy transfer(FRET).The regulation ability of p H can be controlled by the length and sequence of the triplex stem,and the wide p H regulation range may be helpful for the application of DNAzymes in biological medicine delivery systems. 相似文献
177.
Jeonghee Seong Jong Keun Park Hosung Sun 《International journal of quantum chemistry》1996,57(1):79-87
The transition electric dipole moments between low-lying valence states of NH+ are calculated by an ab initio effective valence-shell Hamiltonian (Hv) method. The Hv calculated transition moments are found to be in good agreement with those by other accurate ab initio methods. The spontaneous emission probabilities for the A2− → X2Π, B2Δ → X2Π, and C2−+ → X2Π transitions of NH+ are computed. Also, radiative lifetimes for A2∑−, B2Δ, and C2∑+ states are all theoretically determined using the potential energy functions by Hv. Also, the Hv results are well compared with those computed using the Morse potentials and the rkr potentials which are obtained from experimental data. © 1996 John Wiley & Sons, Inc. 相似文献
178.
Haidong Zhang Zeneng Sun Chengguo Liu Shurui Dong Yuanyuan Shao Jesse Zhu 《Particuology》2021,(2):1-15
The effects of internals and gas distributors on the local dynamics of the bubbles in the conventional gas-solid fluidized bed were studied.Mesh-type internals with different opening areas(50%,70%and 90%)and different arrangements(two-layer and four-layer);and a sintered plate with a smaller pore size(1μm)and a perforated plate with a larger pore size as distributors were investigated.Differential pressure drops and local solids holdups were measured under various superficial gas velocities to compare the performances of the different types of internals and distributors.The instantaneous solids holdup signals from the optical fibre probe were used to further examine the local bubble dynamics in detail.Smaller bubbles were found,with the installation of internals or using the sintered plate,resulting in lower pressure drops and a higher bed expansion.Internals with reduced opening area or distributor with smaller pore size further leads to a higher changeover rate between the bubbles and dense phase,both axially and radially,and hence a better gas-solid contacting and an earlier transition to the turbulent flow regime of the bed. 相似文献
179.
Zengqing Sun Qingyu Tang Xiaohui Fan Min Gan Xuling Chen Zhiyun Ji Xiaoxian Huang 《Molecules (Basel, Switzerland)》2022,27(1)
Alkali-activated materials (AAMs) are considered to be alternative cementitious materials for civil infrastructures. Nowadays, efforts have been made in developing AAMs with self-compacting ability. The obtained self-compacting AAMs (SCAAMs) accomplish superior passing and filling properties as well as excellent mechanical and environmental advantages. This work critically revisits recent progresses in SCAAMs including mixture proportions, fresh properties, mechanical strength, microstructure, acid and sulfate resistance, high temperature behaviors, impact resistance and interface shear strength. To facilitate direct comparison and interpretation of data from different publications, mixture proportions were normalized in terms of the content of key reactive components from precursors and activators, and correlation with mechanical behaviors was made. Moreover, special attention was paid to current research challenges and perspectives to promote further investigation and field application of SCAAMs as advanced construction material. 相似文献
180.
Mengdie Gong Mingyan Tu Hongxia Sun Lu Li Lili Zhu Honglin Li Zhenjiang Zhao Shiliang Li 《Molecules (Basel, Switzerland)》2022,27(1)
Huntington’s disease (HD) is a rare single-gene neurodegenerative disease, which can only be treated symptomatically. Currently, there are no approved drugs for HD on the market. Studies have found that MAPK11 can serve as a potential therapeutic target for HD. Regrettably, no MAPK11 small molecule inhibitors have been approved at present. This paper presents three series of compounds that were designed and synthesized based on the structure of skepinone-L, a known MAPK14 inhibitor. Among the synthesized compounds, 13a and 13b, with IC50 values of 6.40 nM and 4.20 nM, respectively, displayed the best inhibitory activities against MAPK11. Furthermore, the structure–activity relationship (SAR) is discussed in detail, which is constructive in optimizing the MAPK11 inhibitors for better activity and effect against HD. 相似文献