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排序方式: 共有4868条查询结果,搜索用时 15 毫秒
1.
《Ceramics International》2021,47(18):25997-26009
The effects of adding ZrO2 and TiO2 at the expense of MgF2 on the crystallization, microstructure, mechanical properties, thermal properties and electrical properties of mica glass-ceramics based on the SiO2–MgO–MgF2–K2O system were investigated by the differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), microhardness tester and resistivity tester. The electrical properties were discussed emphatically. The results showed that the additions of ZrO2 and/or TiO2 at the expense of MgF2 effectively increase the viscosity, the glass transition temperatures (Tg) and the crystallization temperatures (Tp) of the glasses. The crystallization activation energy (Ec) of the amorphous glasses varied with the nucleating agents was discussed in depth. It was discovered that the nucleating agents had no effect on the crystal phase type but had a certain effect on the crystallinity and microstructure. Tetrasilicic fluoromica and enstatite were precipitated at different crystallization temperatures. Due to the non-stoichiometric ratio of tetrasilicic fluoromica crystal, the prepared glass-ceramics had high dielectric constant (24.4–34.3) and volume resistivity (>2 × 1011 Ω cm) at 25 °C, and the dielectric loss was almost zero. 相似文献
2.
Matteo Di Giosia Alice Soldà Markus Seeger Andrea Cantelli Fabio Arnesano Maria I. Nardella Vincenzo Mangini Francesco Valle Marco Montalti Francesco Zerbetto Stefania Rapino Matteo Calvaresi Vasilis Ntziachristos 《Advanced functional materials》2021,31(20):2101527
Fullerenes are candidates for theranostic applications because of their high photodynamic activity and intrinsic multimodal imaging contrast. However, fullerenes suffer from low solubility in aqueous media, poor biocompatibility, cell toxicity, and a tendency to aggregate. C70@lysozyme is introduced herein as a novel bioconjugate that is harmless to a cellular environment, yet is also photoactive and has excellent optical and optoacoustic contrast for tracking cellular uptake and intracellular localization. The formation, water-solubility, photoactivity, and unperturbed structure of C70@lysozyme are confirmed using UV-visible and 2D 1H, 15N NMR spectroscopy. The excellent imaging contrast of C70@lysozyme in optoacoustic and third harmonic generation microscopy is exploited to monitor its uptake in HeLa cells and lysosomal trafficking. Last, the photoactivity of C70@lysozyme and its ability to initiate cell death by means of singlet oxygen (1O2) production upon exposure to low levels of white light irradiation is demonstrated. This study introduces C70@lysozyme and other fullerene-protein conjugates as potential candidates for theranostic applications. 相似文献
3.
Xianjin Li Tianyu Li Pengcheng Xu Congxin Xie Yunhe Zhang Xianfeng Li 《Advanced functional materials》2021,31(22):2100133
Bromine-based flow batteries (Br-FBs) are considered one of the most promising energy storage systems due to their features of high energy density and low cost. However, they generally suffer from uncontrolled diffusion of corrosive bromine particularly at high temperatures. That is because the interaction between polybromide anions and the commonly used complexing agent (N–methyl–N–ethyl–pyrrolidinium bromide [MEP]) decreases with increasing temperatures, which causes serious self-discharge and capacity fade. Herein, a novel bromine complexing agent, 1–ethyl–2–methyl–pyridinium bromide (BCA), is introduced in Br-FBs to solve the above problems. It is proven that BCA can combine with polybromide anions very well even at a high temperature of 60 °C. Moreover, the BCA contributes to decreasing the electrochemical polarization of Br−/Br2 couple, which in turn improves their power density. As a result, a zinc–bromine flow battery with BCA as the complexing agent can achieve a high energy efficiency of 84% at 40 mA cm−2, even at high temperature of 60 °C and it can stably run for more than 400 cycles without obvious performance decay. This paper provides an effective complexing agent to enable a wide temperature range Br-FB. 相似文献
4.
5.
Stefany Castaldi Claudia Petrillo Giuliana Donadio Fabrizio Dal Piaz Alessio Cimmino Marco Masi Antonio Evidente Rachele Isticato 《International journal of molecular sciences》2021,22(7)
In recent decades, intensive crop management has involved excessive use of pesticides or fertilizers, compromising environmental integrity and public health. Accordingly, there has been worldwide pressure to find an eco-friendly and safe strategy to ensure agricultural productivity. Among alternative approaches, Plant Growth-Promoting (PGP) rhizobacteria are receiving increasing attention as suitable biocontrol agents against agricultural pests. In the present study, 22 spore-forming bacteria were selected among a salt-pan rhizobacteria collection for their PGP traits and their antagonistic activity against the plant pathogen fungus Macrophomina phaseolina. Based on the higher antifungal activity, strain RHFS10, identified as Bacillus vallismortis, was further examined and cell-free supernatant assays, column purification, and tandem mass spectrometry were employed to purify and preliminarily identify the antifungal metabolites. Interestingly, the minimum inhibitory concentration assessed for the fractions active against M. phaseolina was 10 times lower and more stable than the one estimated for the commercial fungicide pentachloronitrobenzene. These results suggest the use of B. vallismortis strain RHFS10 as a potential plant growth-promoting rhizobacteria as an alternative to chemical pesticides to efficiently control the phytopathogenic fungus M. phaseolina. 相似文献
6.
Maria Rita Gulotta Serena Vittorio Rosaria Gitto Ugo Perricone Laura De Luca 《International journal of molecular sciences》2021,22(4)
The modulation of protein-protein interactions (PPIs) by small molecules represents a valuable strategy for pharmacological intervention in several human diseases. In this context, computer-aided drug discovery techniques offer useful resources to predict the network of interactions governing the recognition process between protein partners, thus furnishing relevant information for the design of novel PPI modulators. In this work, we focused our attention on the MUC1-CIN85 complex as a crucial PPI controlling cancer progression and metastasis. MUC1 is a transmembrane glycoprotein whose extracellular domain contains a variable number of tandem repeats (VNTRs) regions that are highly glycosylated in normal cells and under-glycosylated in cancer. The hypo-glycosylation fosters the exposure of the backbone to new interactions with other proteins, such as CIN85, that alter the intracellular signalling in tumour cells. Herein, different computational approaches were combined to investigate the molecular recognition pattern of MUC1-CIN85 PPI thus unveiling new structural information useful for the design of MUC1-CIN85 PPI inhibitors as potential anti-metastatic agents. 相似文献
7.
Océane Florès Dr. Denis Velic Nesrine Mabrouk Prof. Ali Bettaïeb Christophe Tomasoni Prof. Jean-Michel Robert Dr. Catherine Paul Dr. Christine Goze Christos Roussakis Dr. Ewen Bodio 《Chembiochem : a European journal of chemical biology》2019,20(17):2255-2261
A family of bi- and tetrametallic gold(I) phosphine dithiocarbamate complexes were synthesized, starting from cyclam and dimethylcyclam polyazamacrocycles, respectively, along with their monometallic gold(I) chloridophosphine precursors. Their antiproliferative properties were evaluated on two cancer cell lines (A549 and NSCLC-N6-L16). Most of the mono- and bimetallic complexes displayed strong activities and, in particular, one bimetallic derivative showed antiproliferative properties in the low micromolar range. Insights into the structure–activity relationships are given, along with determination of the thioredoxin reductase inhibition potential, two-photon imaging of the fluorescent derivatives, and evaluation of gold uptake. 相似文献
8.
Dr. Shukun Li Dr. Yamei Liu Ruirui Xing Prof. Dr. Xuehai Yan 《Chembiochem : a European journal of chemical biology》2019,20(4):555-560
Peptide self-assembly, inspired by the naturally occurring fabrication principle, remains the most attractive in constructing fluorescent nanoagents towards bioimaging. However, the noncovalent interactions that drive peptide self-assembly are usually susceptible to the complex physiological environment; thus leading to disassembly and dysfunction of fluorescent nanoagents. Herein, a covalently crosslinked assembly strategy for fabrication of stable peptide-based nanoparticles with adjustable emission is introduced. In the process of cationic diphenylalanine peptide (H-Phe-Phe-NH2 ⋅ HCl) self-assembly, glutaraldehyde is used as a crosslinker and the resulting product of the Schiff base reaction can be fluorescent. More importantly, the emission wavelength can be readily tuned by controlling the covalent reaction time. It has been demonstrated that the nanoparticles are stable, even after intracellular uptake, and can be used for sustainable multicolor fluorescent imaging. The strategy with integrating peptide self-assembly and covalent crosslinking could be promising for the design and engineering of functional fluorescent nanoparticles with robust physiological stability and adjustable emission towards improved bioimaging applications. 相似文献
9.
Dr. Tom Baladi Dr. Nedra Hamouda-Tekaya Dr. Leticia Christina Pires Gonçalves Dr. Stéphane Rocchi Dr. Cyril Ronco Dr. Rachid Benhida 《ChemMedChem》2020,15(13):1113-1117
Sulfonylguanidines are interesting bioactive compounds with a broad range of applications in the treatment of different pathologies. 2-Aminobenzazole-based structures are well employed in the development of new anticancer drugs. Two series of novel N-benzazol-2-yl-N′-sulfonyl guanidine derivatives were synthesized with the sulfonylguanidine in either an extra- or intracyclic frame. They were evaluated for their antiproliferative activity against malignant melanoma tumor cells, thus allowing structure-activity relationships to be defined. Additionally, NCI-60 screening was performed for the best analogue to study its efficiency against a panel of other cancer cell lines. The stability profile of this promising compound was then validated. During the synthetic process, an unexpected new deamidination of the sulfonylguanidine towards sulfonamide function was also identified. 相似文献
10.
Prof. Chiara Brullo Dr. Federica Rapetti Prof. Silvana Alfei Dr. Irena Maric Dr. Francesca Rizzelli Dr. Marina Mapelli Dr. Camillo Rosano Dr. Maurizio Viale Prof. Olga Bruno 《ChemMedChem》2020,15(11):961-969
Even though immunotherapy has radically changed the search for anticancer therapies, there are still many different pathways that are open to intervention with traditional small molecules. To expand our investigation in the anticancer field, we report here a new series of compounds in which our previous pyrazole and imidazopyrazole scaffolds are linked to a differently decorated phenyl ring through an acylhydrazone linker. Preliminary tests on the library were performed at the National Cancer Institute (USA) against the full NCI 60 cell panel. The best compounds among the imidazopyrazole series were then tested by immunofluorescence staining for their inhibition of cell proliferation, apoptosis induction, and their effect on the cell cycle and on microtubules. Two compounds, in particular 4-benzyloxy-3-methoxybenzyliden imidazopyrazole-7-carbohydrazide showed good growth inhibition, with IC50 values in the low-micromolar range, and induced apoptosis. Both compounds altered the cell-cycle phases with the appearance of polyploid cells. Immunofluorescence analysis evidenced microtubules alterations; tubulin polymerization assays and docking studies suggested the tubulin system to be the possible, although not exclusive, target of the new acylhydrazone series reported here. 相似文献