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排序方式: 共有450条查询结果,搜索用时 766 毫秒
21.
Sylvie Skalickova Pavel Horky Veronika Mlejnkova Jiri Skladanka Bozena Hosnedlova Branislav Ruttkay‐Nedecky Carlos Fernandez Rene Kizek 《Chemical record (New York, N.Y.)》2021,21(1):17-28
Polysaccharide nanoparticles are promising materials in the wide range of disciplines such as medicine, nutrition, food production, agriculture, material science and others. They excel not only in their non‐toxicity and biodegradability but also in their easy preparation. As well as inorganic particles, a protein corona (PC) around polysaccharide nanoparticles is formed in biofluids. Moreover, it has been considered that the overall response of the organism to nanoparticles presence depends on the PC. This review summarises scientific publications about the structural chemistry of polysaccharide nanoparticles and their impact on theranostic applications. Three strategies of implementation of the PC in theranostics have been discussed: I) Utilisation of the PC in therapy; II) How the composition of the PC is analysed for specific disease markers; III) How the formed PC can interact with the immune system and enhances the immunomodulation or immunoelimination. Thus, the findings from this review can contribute to improve the design of drug delivery systems. However, it is still necessary to elucidate the mechanisms of nano‐bio interactions and discover new connections in nanoscale research. 相似文献
22.
Nouemsi Soubgui Epiphanie Tene Fongang Rufin Theophile Kamseu Elie Oum Lissouck Rene Andreola Fernanda Boubakar Likiby Rossignol Sylvie Leonelli Cristina 《Journal of Thermal Analysis and Calorimetry》2021,145(6):3003-3018
Journal of Thermal Analysis and Calorimetry - The influence of drying on the microstructure, physical and chemical properties of some tropical wood species has been investigated using... 相似文献
23.
Restraint of the Differentiation of Mesenchymal Stem Cells by a Nonfouling Zwitterionic Hydrogel 下载免费PDF全文
Tao Bai Fang Sun Lei Zhang Andrew Sinclair Sijun Liu Jean‐Rene Ella‐Menye Ying Zheng Prof. Shaoyi Jiang 《Angewandte Chemie (International ed. in English)》2014,53(47):12729-12734
The success of human mesenchymal stem cell (hMSC) therapies is largely dependent on the ability to maintain the multipotency of cells and control their differentiation. External biochemical and biophysical cues can readily trigger hMSCs to spontaneously differentiate, thus resulting in a rapid decrease in the multipotent cell population and compromising their regenerative capacity. Herein, we demonstrate that nonfouling hydrogels composed of pure poly(carboxybetaine) (PCB) enable hMSCs to retain their stem‐cell phenotype and multipotency, independent of differentiation‐promoting media, cytoskeletal‐manipulation agents, and the stiffness of the hydrogel matrix. Moreover, encapsulated hMSCs can be specifically induced to differentiate down osteogenic or adipogenic pathways by controlling the content of fouling moieties in the PCB hydrogel. This study examines the critical role of nonspecific interactions in stem‐cell differentiation and highlights the importance of materials chemistry in maintaining stem‐cell multipotency and controlling differentiation. 相似文献
24.
Patrick J. Whitham Dennis P. Strommen Sandra Lundell Lisa D. Lau Rene Rodriguez 《Plasma Chemistry and Plasma Processing》2014,34(4):755-766
The plasma enhanced chemical vapor depositions of germanium chalcogenide thin films from germanium tetrachloride, hydrogen sulfide and alkyl chalcogenides were studied to determine the viability of these reagents for thin film deposition. Hydrogen sulfide is a commonly used reagent for this technique and was used to determine optimal reaction conditions for thin film deposition. Germanium tetrachloride, alkylsulfides and alkylselenides were also employed because of their lower potential toxicities and higher availabilities compared to their more typical congeners: germane, hydrogen sulfide and hydrogen selenide in the formation of germanium chalcogenides. Alkylsulfides were found to be unsuitable for the deposition of germanium sulfides, however alkylselenide precursors were used successfully for the deposition of germanium selenides. The relative mass flow rates, reactor pressure, substrate temperature and plasma power density were studied for their effects on germanium chalcogenide deposition. These parameters affected the composition, deposition rate, film quality, and spectroscopic properties of the deposited films. 相似文献
25.
Liquid-liquid(L-L)de-mixing and vitrification of solutions of either crystallizable poly(L-lactic acid)(PLLA)or non-crystallizable poly(D/L-lactic acid)(PDLLA)with 50 m%N,N-diethyl-3-methylbenzamide(DEET)were analyzed by calorimetry and cloud-point measurements,which allows drawing conclusions about the effect of polymer stereochemistry on the phase behavior.Regardless of the PLA stereochemistry,vitrification of the solutions on fast cooling,hindering crystallization of PLLA,occurred below-20℃ and suppressed prior L-L de-mixing.The experimental results prove that crystallization in samples containing crystallizable PLLA,observed at around 55℃ on slow cooling,is not preceded by L-L de-mixing. 相似文献
26.
Jean Sala-Pala Jacques Amaudrut Jacques E. Guerchais Rene Mercier Jacques Douglade Jean Gerard Theobald 《Journal of organometallic chemistry》1980,204(3):347-359
Hexafluorobutyne (CF3CCCF3 = Hfb) reacts with Cp2NbH3 (Cp = η5-C5H5) affording five new complexes I–V, whose structures have been studied by mass, Ir, ESR and NMR spectroscopy. The X-ray study of II shows the presence of a planar NbC4 ring Nb—C(1): 2.25(5); C(1)—C(2): 1.31(7); C(2)—C(3): 1.53(8); C(3)—(4): 1.34(7); C(4)—Nb: 2.23(5) Å. With trifluoropropyne (CF3CCH = tfp), only the analog of III, i.e. Cp2NbFf(tfpH), has been isolated. 相似文献
27.
28.
Forrer J Schmutz H Tschaggelar R Schweiger A 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2004,166(2):220-251
Direct detection of free induction decays and electron spin echoes, and the recording of echo-detected EPR spectra and electron spin echo envelope modulation patterns at a microwave frequency of 2.5 GHz is demonstrated. This corresponds to the measurement of the transverse magnetization in the laboratory frame, rather than in the rotating frame as usually done by down-converting the signal (homodyne detection). An oscilloscope with a 6-GHz analog bandwidth, a sampling rate of 20 GigaSamples per second, and a trigger frequency of 5 GHz for the edge trigger and 750 MHz for the advanced trigger, is used in these experiments. For signal averaging a 3-GHz microwave clock divider has been developed to synchronize the oscilloscope with the frequency of the EPR signal. Moreover, direct detection of continuous wave EPR signals at 2.5 GHz is described. 相似文献
29.
Rene L. Schilling 《Integral Equations and Operator Theory》2001,41(1):74-92
Let (A, D(A)) denote the infinitesimal generator of some strongly continuous sub-Markovian contraction semigroup onL
p
(m), p1 andm not necessarily -finite. We show under mild regularity conditions thatA is a Dirichlet operator in all spacesL
q
(m), qp. It turns out that, in the limitq,A satisfies the positive maximum principle. If the test functionsC
c
D(A), then the positive maximum principle implies thatA is a pseudo-differential operator associated with a negative definite symbol, i.e., a Lévy-type operator. Conversely, we provide sufficient criteria for an operator (A, D(A)) onL
p(m) satisfying the positive maximum principle to be a Dirichlet operator. If, in particular,A onL
2
(m) is a symmetric integro-differential operator associated with a negative definite symbol, thenA extends to a generator of a regular (symmetric) Dirichlet form onL
2
(m) with explicitly given Beurling-Deny formula. 相似文献
30.