查看更多>>摘要：Studies have demonstrated that the viscosity and SO2 in mitochondria are involved in various physiological processes, which are both important for maintaining the normal function of mitochondria. In this research, we rationally designed and synthesized a novel mitochondria-targetable fluorescent probe Mito-MG with near-infrared absorption and emission for dual-response of viscosity and SO2. Based on the TICT mechanism and Michael addition reaction, the probe Mito-MG responds to viscosity and SO2 with different near-infrared fluorescence signals. Importantly, Mito-MG presented outstanding mitochondrial targeting ability (Pearson's colocalization coefficient is 0.8602) and has been successfully applied to imaging of the cells, zebrafish and mice. We believe that Mito-MG could be applied as a powerful tool for a deep understanding of the connection of viscosity and SO2 in biological systems. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：Nitric oxide (NO), an essential biological messenger molecule, participates in various physiological and pathological processes. The sensitive and specific detection of NO is of great significance for understanding the biological function of NO. Here, we synthesized a fluorescent probe (Rho-NO) for highly selective detection of NO both in vitro and in vivo. The high selectivity of Rho-NO is attributed to the fact that NO is easily replaced by electron donor amino group to form N-nitrosation products, causing rhodamine spiro ring open and fluorescence emit. Rho-NO showed a good linear response to NO (0-100 mu M) with a low detection limit (0.06 mu M). Importantly, it exhibited excellent specificity for NO detection in human serum and was also applied for imaging NO in living cells and inflammatory model of zebrafish. This work proves the potential of Rho-NO in pathological research and disease diagnosis. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：One of the most important areas of medical science is oncology, which is responsible for both the diagnostics and treatment of cancer diseases. Simultaneously one of the main challenges of oncology is the development of modern drugs effective in the fight against cancer. Statins are a group of biologically active compounds with the activity of 3-hydroxy-3-methyl glutaryl-CoA reductase inhibitors, an enzyme catalyzing the reduction of 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) to mevalonic acid. By acting on this enzyme, statins inhibit the endogenous cholesterol synthesis which in turn causes the reduction of its systemic concentrations. However, in vitro and in vivo studies confirm also the cytostatic and cytotoxic effects of statins against various types of cancer cells including colon cancer. In the presented studies the influence of mevastatin on cancerous colon cells CaCo-2 by Raman spectroscopy and imaging is discussed and compared with biochemistry characteristic for normal colon cells CCD-18Co. Based on vibrational features of colon cells: normal cells CCD-18Co, cancerous cells CaCo-2 and cancerous cells CaCo-2 treated by mevastatin in different concentrations and incubation times we have confirmed the influence of this statin on biochemistry composition of cancerous human colon cells. Moreover, the spec-troscopic results for colon normal cells and cancerous cells based on data typical for nucleic acids, pro-teins, lipids have been compared. The cytotoxisity of mevastatin was determined by using XTT tests. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
查看更多>>摘要：Ratio fluorescence has attracted much attention because of its self-calibration properties. However, it is difficult to obtain suitable fluorescent materials with well-resolved signals simultaneously under one excitation. In this work, we report a different strategy, using MIL-68(In)-NH2 as both the fluorescence element and the scattered light unit, and coupling the fluorescence and the scattered light to construct the fluorescence and scattered light ratio system. Based on the optical properties and the second-order scattering (SOS) of the material nanoparticles, the synthesized MIL-68(In)-NH2 can be used to realize the ratio detection of Hg2+. Because the scattering intensity of small particle MIL-68(In)-NH2 is weak, SOS is not obvious. When Hg2+ is introduced the coordination reaction between the amino nitrogen atoms of MIL-68(In)-NH2 and Hg2+ make the particles larger, resulting in the decrease of fluorescence and the enhancement of SOS. As a result, a novel He ratiometric detection method is developed by using the dual signal responses of the fluorescence and scattering. Under the optimal conditions (pH = 6, reaction time 5 min, room temperature, and the maximum excitation wavelength 365 nm), the linear range of the method is 0-100 mu M, and the detection limit is 5.8 nM (Ksv = 9.89 x 10(9) M-1). In addition, the probe is successfully used to evaluate Hg2+ in actual water samples. Compared with the traditional method of recording only the fluorescence signal, the proposed fluorescence-scattering method provides a new strategy for the design of ratiometric sensors. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Interaction type of modafinil with calf thymus DNA (ct-DNA) was examined systematically using ethidium bromide (EB) as a fluorescence probe by fluorescence spectroscopy, UV-Vis spectroscopy, viscosity and molecular docking method. The fluorescence quenching mechanism of ct-DNA-EB by modafinil can be combination of static and dynamic quenching. Results of UV-Vis absorption, competitive binding with Hoechst 33258, ionic strength effect studies, viscosity measurements were confirmed that the interaction type of modafinil with ct-DNA was intercalation. According to docking studies R-modafinil showed better interaction with ct-DNA which is consistent with known pharmacological properties of modafinil. The calculated thermodynamic parameters, enthalpy and entropy change, suggested that the driven forces are hydrogen bonding or van der Walls forces. Results of the docking studies were compatible with the experimental results and confirmed the hydrogen bond formation between modafinil and ct-DNA. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：Quantitative gas measurement under the condition of unknown optical path length is a challenge in laser absorption spectroscopy technology field. In this paper, we proposed a tunable diode laser absorption spectroscopy line shape analysis (TDLAS-LSA) method for simultaneous measurement of water vapor concentration and effective optical path length (EOPL) under unknown optical path conditions. A single H2O absorption line near 1383.9 nm (7226.02 cm(-1)) was selected, and its line strength, self-broadening coefficient and temperature-dependence coefficient were measured experimentally to improve the HITRAN databases. The Lorentz broadening and line area were accurately extracted by Hartmann-Tran profile (HTP) fitting, and the gas concentration and EOPL were calculated based on the spectral line shape analysis method. Eight concentrations of water vapor in the range of 146 ppm similar to 4.39% were measured experimentally, and the maximum average deviation between the TDLAS-LSA method and the commercial sensor was less than 7.1%. Comparing the EOPL with mechanical measurement, the maximum deviation of multiple measurements is less than 5.7%. The results showed that the TDLAS-LSA method can effectively perform gas sensing under unknown optical path conditions, and has great application potential in low-cost, in-situ and multi-parameter simultaneous measurement. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：Herein, we report a novel analytical exploitation of selective but very facile anion exchange induced phase transformations of CsPbBr3 Perovskite crystallites. Specifically, with CsPbBr3 Perovskite as Spectrofluorimetric probes, we demonstrate a simple, quick and economical analytical procedure for sensing and quantification of chloride content in room temperature ionic liquids (RTILs), and that of toxic pollutant Arsenic (III) in water samples. The presented approach relies on the variations in photoluminescence characteristics of CsPbBr3 Perovskite nanoplatelets on account of very facile substitution of their bromide ions by chloride ions available in their vicinity. This unique property of CsPbBr3 Perovskite nanoplatelets ensures detection of chloride impurity in RTIL samples, within the concentration range of 0.007-0.016 ppb with LOD c.a. 0.0010 ppb +/- 0.44% and of Arsenic in water samples within the concentration range 0.48-4.32 ppb with LOD as low as c.a. 0.074 ppb +/- 0.46%. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：Rhubarb has been used as herbal purgative with a long and worldwide history. But purgation is a side effect of rhubarb in many cases. In traditional Chinese medicine, rhubarb can be stir-baked to scorch to attenuate the purgative function while enhance other bioactivities such as the anti-inflammatory effect. However, the over-scorched rhubarb will lose necessary active ingredients and even generate toxic ingredients. Nowadays, the scorching degree of rhubarb is still determined by the intuitive observation of color changes in production. Therefore, this research was designed to develop more reasonable and objective criteria to evaluate the scorching degree to ensure the efficacy, safety and consistency of the scorched rhubarb. Taking the example of the rhubarb baked at 200 degrees C for different times, the combination of trait indicator (color), chemical indicator (combined and free AQs, sennosides, gallic acid, 5-HMF) and biological indicator (anti-inflammatory) showed that the rhubarb baked for 30 min can be treated as the right scorched. Two-dimensional correlation spectroscopy helped to reveal the infrared spectral markers of the water extract near 1694 cm(-1),1442 cm(-1) and 825 cm(-1), as well as the relative strength of the absorption bands of the powder near 1610 cm(-1) and 1020 cm(-1), to discriminate the right-scorched and over-scorched rhubarb. In conclusion, the combination of trait, chemical and biological indicators can provide reasonable and objective criteria for the optimum scorching degree of rhubarb, while FTIR spectroscopy can assess the right endpoint of the scorching process in a rapid, cheap and green way. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Hydrogen sulfide (H2S) has been recently regarded as one of the most important gasotransmitters in the metabolic system, while abnormal H2S concentration is associated with various diseases. Although numerous fluorescent probes have been developed for the detection of cellular H2S, only a few of them can monitor lysosomal H2S with ratiometric fluorescent output. Here, we developed a water-soluble probe 1 toward H2S by introducing 2,4-dinitrophenyl ether into a novel merocyanine-based dye. As expected, H2S induced an obvious red-shift of the probe from 520 nm to 580 nm in neat aqueous solution, and this fluorescent ratiometric response is highly selective and sensitive (with the detection limit of 0.81 nM), rapid (within 10 s), and effective in a wide pH range (2.0-10.0). In particular, the probe was successfully applied for tracing H2S in the lysosomes of living cells and in zebrafish. (C) 2021 Elsevier B.V. All rights reserved.
查看更多>>摘要：In this study, we focused on physical characterization and quality control of dry fig, jujube, pomegranate, date palm and concentrated grape vinegars using UV spectroscopy method and rheology technique. The optical spectra and flow behaviour of the vinegars were analysed in detail in the selected specific wavelength, shear rate and frequency ranges, respectively. It was determined that the peak values seen in the UV spectra of the vinegars were caused by the organic acid and phenolic compound concentration. The peak values in the UV spectra of the vinegars wavelength range of 190 nm to 240 nm and 250 nm to 300 nm were caused by the organic acid and phenolic compound concentration, respectively. In this context, it was predicted that concentrated grape vinegar, which has the highest absorbance value, has higher organic acid content and more antibacterial/antioxidant properties compared to the others. It is thought that the optical energy gaps of vinegars are related to the organic acid concentration and the release time. Flow properties of the vinegars were non-Newtonian thickening fluids (dilatant fluids) and compatible with the Power law model. The stable flow of the vinegars in the high shear rate region was interpreted as having a successful production process and being of good quality. (C) 2021 Published by Elsevier B.V.
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