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21.
22.
《Journal of Saudi Chemical Society》2023,27(5):101690
This study reports the adsorption efficacy of hydroxyapatite (HAp) for removing Congo Red (CR) dye from aqueous solution. HAp was synthesized utilizing chicken eggshell as a precursor of Ca source. Solid state synthesis method was implemented which comprised calcination at 950 °C (E-HAp950). XRD analysis confirmed the formation of bi-phasic HAp with 15.5% of β-TCP. Elemental composition was evaluated by XPS and EDX analysis. FESEM analysis revealed the particles are of plate and spherical shaped also confirmed by the TEM images. DLS particle size, zeta potential, BET surface area and point of zero charge were also evaluated. Adsorption efficacy of E-HAp950 for removing CR was evaluated by batch adsorption experiment. Maximum adsorption capacity (qmax) was found to be 9.64 mgg−1 which was best explained by the non-linear fitting (R2 = 0.98) of Langmuir isotherm. Adsorption kinetics profusely followed pseudo second order kinetic model (R2 = 0.999) with qe (experimental) being very much closer to qe (calculative) for this model. Thus, hydroxyapatite prepared by utilizing eggshell waste through solid state method has the potential to remove toxic dyes. 相似文献
23.
《Arabian Journal of Chemistry》2022,15(10):104116
The misuses of veterinary drugs can result in the accumulation of residues in food of animal origin that can make its way to the final consumer. Herein we describe a simple method for the accurate determination of beta-lactams, quinolones, sulphonamides, and tetracyclines in fish, poultry, and red meat. No extraction cartridges were used; instead, the extraction process consisted of the addition of an organic solvents, shaking, centrifugation, and dilution. An extensive validation process demonstrated an excellent linearity (R2 ≥ 0.99) for 23-drug residues. The recovery of drugs in different matrices at two concentration levels (n = 6) was in the range of 82–119%. The method was proved to be repeatable and reproducible with intra/inter-day measurements (RSDs lower than 20%). The quantification limits of drug residues were in the range of 0.8 to 45.3 ug/kg, which is well below the maximum residue limits set by most regulatory authorities. This method was successfully applied to the routine analysis of 20 fish, poultry, and red meat samples (n = 60). 相似文献
24.
WU Liting XIN Yujia GUO Zhaoyang GAO Wei ZHU Yanpeng br WANG Yinsong RAN Ruixue YANG Xiaoying 《高等学校化学研究》2022,38(2):562-571
Combining photothermal therapy and radiotherapy(PTT-RT) with reducing tumor hypoxia acts as an important antitumor modality. However, it is a great challenge to realize photothermal therapy, radiotherapy and exogenous oxygen supply in one nanosystem. To realize a combination of the three functions, we fabricated a red blood cell membrane(RBCm)-camouflaged, red blood cell content(RBCc) and the copper sulfide(CuS) co-loaded dendritic large pore mesoporous silica nanoparticle(DLMSN/CuS/RBCc/ RBCm). The cell membrane coating endowed the nanoparticles with good stability in the physiological environment, and CuS allowed the nanoparticle exhibiting good photothermal and radiosensitization properties. RBCc loaded nanoparticle DLMSN/CuS/RBCc enhanced superior anti-tumor effect than DLMSN/CuS during combined PTT-RT therapy because the introduction of RBCc increased the exogenous oxygen supply. The in vitro study further demonstrated that the combination of photothermal therapy and radiotherapy induced superior antitumor efficacy than single therapy. Our work thus presents a unique multifunctional nanoscale platform favorable for combined PTT and RT. 相似文献
25.
Dr. Ziyu Wang Dr. Ya Zhang Dr. Cheng Chen Dr. Ruixue Zhu Dr. Jiaming Jiang Prof. Tsu-Chien Weng Prof. Quanjiang Ji Prof. Yifan Huang Prof. Chong Fang Prof. Weimin Liu 《Angewandte Chemie (International ed. in English)》2023,62(5):e202212209
Large Stokes shift (LSS) red fluorescent proteins (RFPs) are highly desirable for bioimaging advances. The RFP mKeima, with coexisting cis- and trans-isomers, holds significance as an archetypal system for LSS emission due to excited-state proton transfer (ESPT), yet the mechanisms remain elusive. We implemented femtosecond stimulated Raman spectroscopy (FSRS) and various time-resolved electronic spectroscopies, aided by quantum calculations, to dissect the cis- and trans-mKeima photocycle from ESPT, isomerization, to ground-state proton transfer in solution. This work manifests the power of FSRS with global analysis to resolve Raman fingerprints of intermediate states. Importantly, the deprotonated trans-isomer governs LSS emission at 620 nm, while the deprotonated cis-isomer's 520 nm emission is weak due to an ultrafast cis-to-trans isomerization. Complementary spectroscopic techniques as a table-top toolset are thus essential to study photochemistry in physiological environments. 相似文献
26.
Uniform and sphere-like nanoparticles of crystalline Pr3+-doped CaTiO3 have been prepared from complex polymer precursor at 600°C, in which, metal atoms are previously dispersed by citric acid in ethylene glycol solvent. The decomposition process of the precursor, crystallization, and particle sizes of CaTiO3 have been investigated by using thermal analysis, powder X-ray diffraction and transmission electron microscopy. Diffuse reflectance spectra, photoluminescence and decay curve indicate that a strong red emission located at the nearly NTCS “ideal red” site is deduced from the energy transfer from the band gap absorption to doping Pr3+ ions. The thermoluminescence curves exhibit that a potential long phosphorescent material based on Pr3+-doped CaTiO3 will be explored in future. 相似文献
27.
The effect of different alternative techniques to the traditional aging on lees on the low molecular weight phenolic compounds of red wines was study as well as their evolution during the aging in oak wood barrels for six months. The study was carried out with Tempranillo red grapes from two consecutive vintages. The techniques assayed were the traditional aging on lees with or without the addition of exogenous β-glucanase enzymes, the use of yeast derivative preparations also with or without the addition of exogenous β-glucanase enzymes, the micro-oxygenation applied together with the aging on lees, and the use of non-toasted oak wood chips. 相似文献
28.
《Analytical letters》2012,45(5):955-969
ABSTRACT Simple, sensitive and selective methods for the determination of trimethoprim (TMP) in pure form and in pharmaceutical formulations are described. The methods are based on the reaction of TMP as a π-electron donor with bromothymol blue (BTB), bromocresol green (BCG) and alizarin red S (ARS) as electron acceptors. The coloured products are quantified spectrophotometrically at their corresponding λmax. Beer's law is obeyed in case of BTB in the range 2.9-23.2 μg/ml (CHCl3), 2.9-20.0 μg/ml (CH2Cl2) and 5.0-29.0 μg/ml (ClC6H5), in the case of BCG 2.9-27.5 μg/ml (H2O/alc.), 2.9-18.3 μg/ml (CHCl3) and 2.9-20.3 μg/ml (CH2Cl2) and for ARS in the range 3.0-12.0 μg/ml in H2O/alc medium. The specific absorptivities, molar absorptivities, Sandell sensitivities, standard deviations and percent recoveries are evaluated. Application of the suggested methods to dosage forms is presented and compared with the pharmacopoeial method. The interference from additives and sulfa compounds, especially sulfamethoxazole, has been overcome by extraction into chloroform or methylene chloride. 相似文献
29.
平行因子分析在赤潮藻滤液三维荧光光谱特征提取中的应用 总被引:1,自引:0,他引:1
在实验室条件下培养我国沿海常见的10种赤潮藻,测定了赤潮藻生长过程中藻滤液的三维荧光光谱.用平行因子分析对光谱进行分解,获得每种赤潮藻滤液荧光峰的个数及类型,即每种赤潮藻的特征光谱.在此基础上比较每种藻特征光谱的相似性和差异性,并分析了赤潮藻生长过程中滤液的荧光峰强度和生长阶段的关系,为基于赤潮藻滤液三维荧光光谱的赤潮藻种类识别测定技术提供依据.结果表明:不同赤潮藻的特征光谱之间存在差异.在指数生长期,类蛋白和类腐殖质荧光峰强度与藻密度呈正相关,说明两类有机物在水体中不断积累;在稳定期和衰亡期,两类有机物的荧光强度迅速增大,这可能是衰老和死亡细胞的破碎释放,以及细菌降解作用所致.平行因子分析可以有效提取赤潮藻的荧光特征,考察了赤潮藻荧光峰强度和生长阶段的关系. 相似文献
30.
W. Russ Algar 《Analytica chimica acta》2010,673(1):1-25
A comprehensive review of the development of assays, bioprobes, and biosensors using quantum dots (QDs) as integrated components is presented. In contrast to a QD that is selectively introduced as a label, an integrated QD is one that is present in a system throughout a bioanalysis, and simultaneously has a role in transduction and as a scaffold for biorecognition. Through a diverse array of coatings and bioconjugation strategies, it is possible to use QDs as a scaffold for biorecognition events. The modulation of QD luminescence provides the opportunity for the transduction of these events via fluorescence resonance energy transfer (FRET), bioluminescence resonance energy transfer (BRET), charge transfer quenching, and electrochemiluminescence (ECL). An overview of the basic concepts and principles underlying the use of QDs with each of these transduction methods is provided, along with many examples of their application in biological sensing. The latter include: the detection of small molecules using enzyme-linked methods, or using aptamers as affinity probes; the detection of proteins via immunoassays or aptamers; nucleic acid hybridization assays; and assays for protease or nuclease activity. Strategies for multiplexed detection are highlighted among these examples. Although the majority of developments to date have been in vitro, QD-based methods for ex vivo biological sensing are emerging. Some special attention is given to the development of solid-phase assays, which offer certain advantages over their solution-phase counterparts. 相似文献