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991.
Two new three‐dimensional (3D) LnIII metal‐organic frameworks (MOFs) were designed and successfully obtained via a solvothermal reaction between lanthanide(III) nitrates and a semi‐flexible carbazole tetracarboxylate acid linker as a high‐performance chromophore. 1 and 2 possess porous 3D networks with channels along the a axis, and more importantly, they show a highly sensitive and selective fluorescence quenching response to Fe3+ and CrVI anions. The sensing mechanism investigation revealed that the weak interactions of Fe3+ with nitrogen atoms of carbazole and deprotonated carboxylic acids protruding into the pores of MOFs quenched the luminescence of 1 and 2 effectively. In addition, the competition absorption also played an important role in the luminescence quenching detection of Fe3+ based on 1 , and CrVI anions based on 1 and 2 . Therefore, 1 and 2 represent an alternative example of regenerable luminescence based sensors for the quantitative detection of Fe3+ and CrVI anions. 相似文献
992.
Shiyu Luo Juan Wu Zhanrong Jia Pengfei Tang Jun Sheng Chaoming Xie Chen Liu Donglin Gan Dong Hu Wei Zheng Xiong Lu 《Macromolecular bioscience》2019,19(9)
Significant attention has been focused on bone tumor therapy recently. At present, the treatment in clinic typically requires surgical intervention. However, a few tumor cells remain around bone defects after surgery and subsequently proliferate within several days. Thus, fabrication of biomaterials with dual functions of tumor therapy and bone regeneration is significant. Herein, the injectable hydrogel containing cisplatin (DDP) and polydopamine‐decorated nano‐hydroxyapatite is prepared via Schiff base reaction between the aldehyde groups on oxidized sodium alginate and amino groups on chitosan. The hydrogel exhibits sustained release properties for DDP due to the immobilization of DDP via abundant functional groups on polydopamine (PDA). Additionally, given the intense absorption of PDA in the near‐infrared region, the hydrogel exhibits excellent photothermal effects when exposed to the NIR laser (808 nm). Based on the properties, the hydrogel effectively ablates tumor cells (4T1 cells) in vitro and suppresses tumor growth in vivo. Furthermore, the hydrogel promotes the adhesion and proliferation of bone mesenchymal stem cells in vitro due to the abundant functional groups on PDA and further induces bone regeneration in vivo. Therefore, the study extends research on novel biomaterials with dual functions of tumor therapy and bone regeneration. 相似文献
993.
以4-N,N-二乙基氨基水杨醛为原料,制备了2-(苯并噻唑-2-基)-5-(N,N-二乙基氨基)苯酚衍生物(探针L),并对其结构进行了表征。在DMSO/PBS(体积比3∶7,pH=7.4)溶液中,探针L具有高选择性并可荧光"关-开"识别H_2S,在365nm紫外灯照射下,由无荧光变成蓝色荧光。实验表明,探针L识别H_2S的检测限为2.05×10~(-6)mol/L,pH适用范围为6~9,可用于检测实际水样中的H_2S。 相似文献
994.
Liu Pengcheng Xiao Li Tang Yiwei Chen Yifeng Ye Longgang Zhu Yirong 《Journal of Thermal Analysis and Calorimetry》2019,136(3):1323-1332
Journal of Thermal Analysis and Calorimetry - Simple and environment-friendly recovery of valuable metals from spent LIBs was explored. The experimental method, which included reduction roasting... 相似文献
995.
Jia-Bin Han Ao Guo Prof. Xiang-Ying Tang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(12):2989-2994
A challenging deoxygenation of alkoxyl radicals from readily accessible alcohol derivatives was developed, affording facile synthesis of functionalized alkenes with good functional group tolerance under mild reaction conditions. Because alkoxyl radicals can easily undergo β-fragmentations or hydrogen abstractions, this new strategy for deoxygenation of alkoxyl radicals is highly valuable. Moreover, mechanistic studies revealed that the electron-neutral phosphine acts as the deoxygenation reagent. 相似文献
996.
Dr. Longyu Li Qianming Lin Miao Tang Dr. Andrew J. E. Duncan Prof. Dr. Chenfeng Ke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(46):10768-10781
The rapid development of additive manufacturing techniques, also known as three-dimensional (3D) printing, is driving innovations in polymer chemistry, materials science, and engineering. Among current 3D printing techniques, direct ink writing (DIW) employs viscoelastic materials as inks, which are capable of constructing sophisticated 3D architectures at ambient conditions. In this perspective, polymer designs that meet the rheological requirements for direct ink writing are outlined and successful examples are summarized, which include the development of polymer micelles, co-assembled hydrogels, supramolecularly cross-linked systems, polymer liquids with microcrystalline domains, and hydrogels with dynamic covalent cross-links. Furthermore, advanced polymer designs that reinforce the mechanical properties of these 3D printing materials, as well as the integration of functional moieties to these materials are discussed to inspire new polymer designs for direct ink writing and broadly 3D printing. 相似文献
997.
Yukun Wang Feng Chen Zhuoxin Liu Zijie Tang Qi Yang Yan Zhao Shanyi Du Qiang Chen Chunyi Zhi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(44):15854-15858
Multiple stretchability has never been demonstrated as supercapacitors because the hydrogel used cannot fully recover after being heavily deformed. Now, a highly reversibly stretchable all‐polymer supercapacitor was fabricated using a developed double network hydrogel (DN hydrogel) as electrolyte and pure polypyrrole (PPy) as electrode. The DN hydrogel provides excellent mechanical properties, which can be stretched up to 500 % many times and then restore almost 100 % of the original length. To fabricate the fully recoverable stretchable supercapacitor, we annealed a free‐standing pure conducting polymer film as electrode so that the electrodes induced retardance is minimized. The as‐fabricated DN hydrogel/pure conducting polymer supercapacitors can be perfectly recovered from 100 % strain with almost no residual deformation left and the electrochemical performance can be maintained even after 1000 stretches (but not bending). 相似文献
998.
Linxing Meng Xiaolong Zhou Siyu Wang Yu Zhou Wei Tian Pinit Kidkhunthod Sarayut Tunmee Yongbing Tang Run Long Yu Xin Liang Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(46):16821-16828
A photoelectrochemical (PEC) cell can split water into hydrogen and oxygen with the assistance of solar illumination. However, its application is still limited by excessive bulk carrier recombination and sluggish surface oxygen evolution reaction (OER) kinetics. Taking SnS2 as an example, a promising layered optoelectronic semiconductor, Ar plasma treatment strategy was used to introduce a SnS/SnS2 P?N heterojunction and O?S bond near the surface of a SnS2 nanosheet array, simultaneously increasing the separation efficiency of photogenerated electron–hole pairs in the bulk and lowering the OER overpotential at the surface. The onset potential of the plasma‐treated SnS2 nanosheet array shifts negatively to 0.16 V, and the photocurrent density at 1.23 V vs. RHE boosts to 2.15 mA cm?2, which is 7 times that of pristine SnS2. This work demonstrates a facile plasma treatment strategy to modulate the energy band structure and surface chemical states for improved PEC performance. 相似文献
999.
为提高川芎嗪的抗血小板凝集活性,分别以不同的二胺、2,3-丁二酮和硫辛酸为起始原料,采用溴代、水解、环化、氧化、氢化、取代等反应,通过四条路线合成了7个川芎嗪衍生物,其结构经1H NMR、13C NMR及ESI-MS确证。采用Born比浊法初步测试了化合物的体外抗血小板凝集活性,结果显示,化合物1(IC50=0. 26mmol/L)、2(IC50=0. 27mmol/L)和7(IC50=0. 21mmol/L)对由二磷酸腺苷(ADP)诱导的血小板凝集具有一定的抑制活性,优于先导化合物川芎嗪(IC50=0. 49mmol/L)。因此,在不改变川芎嗪药效团的前提下对其进行不同程度的环化,能明显提高川芎嗪的抗血小板凝集活性,此研究为后期化合物的结构修饰提供了一定的参考价值。 相似文献
1000.
Huilan C Deyan H Tian L Hong Y Wenxia T Jian Chen J Peiju Zheng P Chenggang Chen C 《Inorganic chemistry》1996,35(6):1502-1508
Alkylcobalt(III) Schiff base B(12) model complexes with secondary alkyls or a bulky diamine in the equatorial position were synthesized and characterized. Structures have been first determined by X-ray diffraction analysis for i-C(4)H(9)Co(salen)(gamma-pic) (I), n-C(3)H(7)Co(salen)(gamma-pic) (II) and C(2)H(5)Co(SB) (III), where salen = N,N'-ethylenebis(salicylideneamine) dianion; SB = 1,1,2,2-tetramethyl-N,N'-ethylenebis(salicylideneamine) dianion, gamma-pic = gamma-picoline. Crystal data for I (CoC(26)N(3)O(2)H(30)): space group P2(1)/c with a = 6.661(5) ?, b = 18.612(2) ?, c = 19.533(3) ?, beta = 98.93(1) degrees, V = 2392.10 ?(3), D(calcd) = 1.320 g.cm(-3), Z = 4, and R = 0.048 for 4469 measured reflections. Crystal data for II (CoC(25)N(3)O(2)H(28)): space group P2(1)/c, a = 9.609(6) ?, b = 19.169(8) ?, c = 12.995(9) ?, beta = 106.9(7) degrees, V = 2290.4 ?(3), D(calcd) = 1.332 g.cm(-1), Z = 4, and R = 0.048 for 4358 measured reflections. Crystal data for III (CoC(22)N(2)O(2)H(27)): space group P2(1)/c, a = 8.318(3) ?, b = 21.579(2) ?, c = 11.572(2) ?, beta = 93.35(1) degrees, V = 2073.7 ?(3), D(calcd) = 1.314 g.cm(-1), Z = 4, and R = 0.060 for 3954 measured reflections. The crystal structure data reveal that complexes I and II display six-coordinate octahedral geometry; their Co-C, Co-N bond lengths, as well as the Co-C-C angles, are very close to those in 5'-deoxyadenosylcobalamin. Complex III is one of the very few compounds having five-coordinate square pyramidal geometry and observed instability of the Co-C bond. 相似文献