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941.
Ali Golchin Simzar Hosseinzadeh Aytak Jouybar Masumeh Staji Masoud Soleimani Abdolreza Ardeshirylajimi Arash Khojasteh 《先进技术聚合物》2020,31(7):1519-1531
Wound healing, one of the most complex processes of the body involving the cooperation of several important biomolecules and pathways, is one of the major therapeutic and economic issues in regenerative medicine. The present study aimed to introduce a novel electrospun curcumin (Cur)‐incorporated chitosan/polyvinyl alcohol/carbopol/polycaprolactone nanofibrous composite for concurrent delivery of the buccal fat pad‐derived mesenchymal stem cells (BFP‐MSCs) and Cur to a full‐thickness wound on the mouse model. Scaffolds were characterized structurally using scanning electron microscopy (SEM), fluorescence microscopy imaging and Fourier‐transform infrared spectroscopy, and toxicity of the scaffolds was also evaluated after BFP‐MSC seeding by SEM imaging and 3‐(4,5 dimethyiazol‐2‐1)‐2‐5‐diphenyl tetrazolium bromide (MTT) assay. Then, its influence on the wound‐healing process was investigated as a wound dressing for a full‐thickness skin defect in mouse model. Results demonstrated that the designed composite scaffolds have the capability for cell seeding and support their growth and proliferation. Macroscopic and histopathological characteristics were evaluated at the end of the 7 and 14 days after surgery, and their results showed that our designed scaffold groups accelerated the wound‐healing process compared with the control group. Among those, scaffold/Cur, scaffold/Cur/BFP‐MSC and scaffold/BFP‐MSC groups demonstrated more wound repair efficacy. These results indicated that the combined grafts can be used to improve the wound‐healing process, and therefore, the electrospun nanofibers presented in this study, Cur and BFP‐MSC together, were demonstrated to have promising potential for wound‐dressing applications. 相似文献
942.
Kashif Maqbool Khan Satyajit D. Sarker Ghazanfar Ali Khan Hammad Saleem Shujaat Ali Khan 《Natural product research》2020,34(19):2837-2841
Abstract Trillium govanianum Wall. ex D. Don (Melanthiaceae alt. Trilliaceae), is native to the Himalayas. The present study, for the first time, was undertaken to explore the antimicrobial potential, to determine the minimum inhibitory concentration (MIC) values of the methanol extract of the roots of Trillium govanianum and its solid phase extraction (SPE) fractions by using resazurin microtiter assay (REMA) against Gram positive and Gram negative bacterial registered strains and to carry out phytochemical analysis. The remarkable amount of gallic acid equivalent phenolic and quercetin equivalent flavonoid content was manifested by MeOH extract (20.27?±?3.03?mg GAE/g DW and 9.25?±?0.50?mg QE/g DW respectively). The GC/MS analysis revealed the presence saturated and unsaturated components. Considerable level of antibacterial potential against Gram-positive bacteria (MIC: 2.5-0.009?mg/mL) than against Gram-negative bacteria (MIC: 2.5-0.165?mg/mL) were observed. The use of microtiter plates has the advantage of lower cost, fast and quantitative results. 相似文献
943.
A new electrochemical sensor based on Fe3O4@SiO2‐PANI‐Au nanocomposite was fabricated for modification of glassy carbon electrode (Fe3O4@SiO2‐PANI‐Au GCE). The Fe3O4@SiO2‐PANI‐Au nanocomposite was characterized by TEM, FESEM‐EDS‐Mapping, XRD, and TGA methods. The Fe3O4@SiO2‐PANI‐Au GC electrode exhibited an acceptable sensitivity, fast electrochemical response, and good selectivity for determination of quercetin. Under optimal conditions, the linear range for quercetin concentrations using this sensor was 1.0×10?8 to 1.5×10?5 mol L?1, and the limit of detection was 3.8×10?9 mol L?1. The results illustrated that the offered sensor could be a possible alternative for the measurement of quercetin in food samples and biological fluids. 相似文献
944.
We studied sensor application of a graphene oxide and hematite (α‐Fe2O3/GO) composite electrode well‐characterized by the SEM and XRD. Through differential pulse voltammetry (DPV), oxidation of dexamethasone sodium phosphate (DSP) was studied at the surface of a glassy carbon electrode (GCE) modified with graphene oxide nanosheets (GO) and the α‐Fe2O3/GO composite. The values of the transfer coefficient (α) and the diffusion coefficient (D) of DSP were 0.5961 and 4.71×10?5 cm2 s?1 respectively. In the linear range of 0.1–50 μM, the detection limit (DL) was 0.076 μM. In the second step, a GCE was modified with α‐Fe2O3/GO composite and the DSP measurement step was repeated to analyzed and compare the effects of hematite nanoparticles present on graphene oxide surfaces. According to the results, α and D were 0.52 and 2.406×10?4 cm2 s?1 respectively and the DL was 0.046 μM in the linear range of 0.1–10.0 μM. The sensor is simple, inexpensive and uses blood serum. 相似文献
945.
Nora Abdullah AlFaris Saikh Mohammad Wabaidur Zeid Abdullah Alothman Jozaa Zaidan Altamimi Tahany Saleh Aldayel 《Journal of separation science》2020,43(11):2079-2087
An ultra high performance liquid chromatography‐tandem mass spectrometric method has been developed for the highly sensitive and selective determination of regulated aflatoxins. The extraction of aflatoxins from baby food matrices were performed using liquid–liquid extraction procedure followed by immunoaffinity column cleanup. The higher sensitivity for the determination of target aflatoxins was fulfilled by applying a preconcentration step with immunoaffinity columns after acetonitrile–water extraction. The enhanced selectivity was attained with the triple quadrupole mass analyzer operated in electrospray positive ionization mode. Method validation was tested in five different baby food matrices by recovery experiments. Satisfactory recoveries, between 92 and 103%, with relative standard deviations lower than 8% were achieved in all the tested matrices. The proposed method was found to be specific as no interference peaks were observed for blank samples. The limit of detection of the method was found to be in the range of 0.003–0.008 ng/mL. The validated method was fruitfully applied to the screening of aflatoxins in baby foods and feeds sample retailed in local markets of Riyadh, Saudi Arabia. The obtained levels of all analyzed aflatoxins were below the regulation limits set by European Agency. 相似文献
946.
Feng Li Melisa Rodas Ceballos Sepideh Keshan Balavandy Jingxi Fan Mohammad Mahdi Khataei Yadollah Yamini Fernando Maya 《Journal of separation science》2020,43(9-10):1854-1866
In the last 5 years, additive manufacturing (three‐dimensional printing) has emerged as a highly valuable technology to advance the field of analytical sample preparation. Three‐dimensional printing enabled the cost‐effective and rapid fabrication of devices for sample preparation, especially in flow‐based mode, opening new possibilities for the development of automated analytical methods. Recent advances involve membrane‐based three‐dimensional printed separation devices fabricated by print‐pause‐print and multi‐material three‐dimensional printing, or improved three‐dimensional printed holders for solid‐phase extraction containing sorbent bead packings, extraction disks, fibers, and magnetic particles. Other recent developments rely on the direct three‐dimensional printing of extraction sorbents, the functionalization of commercial three‐dimensional printable resins, or the coating of three‐dimensional printed devices with functional micro/nanomaterials. In addition, improved devices for liquid–liquid extraction such as extraction chambers, or phase separators are opening new possibilities for analytical method development combined with high‐performance liquid chromatography. The present review outlines the current state‐of‐the‐art of three‐dimensional printing in analytical sample preparation. 相似文献
947.
Asghar Mardani Mohammad Reza Afshar Mogaddam Mir Ali Farajzadeh Ali Mohebbi Mahboob Nemati Mohammadali Torbati 《Journal of separation science》2020,43(18):3674-3682
A sample pretreatment method based on the combination of a three‐phase solvent extraction system and deep eutectic solvent‐based dispersive liquid–liquid microextraction has been introduced for the extraction of four organochlorine pesticides in cocoa samples before their determination by gas chromatography‐electron capture detection. A mixture of sodium chloride, acetonitrile, and potassium hydroxide solution is added to cocoa bean or powder. After vortexing and centrifugation of the mixture, the collected upper phase (acetonitrile) is removed and mixed with a few microliters of N,N‐diethanol ammonium chloride: pivalic acid deep eutectic solvent. Then it is rapidly injected into deionized water and a cloudy solution is obtained. Under optimum conditions, the limits of detection and quantification were found to be 0.011‐0.031 and 0.036‐0.104 ng/g, respectively. The obtained extraction recoveries varied between 74 and 92%. Also, intra‐ (n = 6) and interday (n = 4) precisions were less than or equal to 7.1% for the studied pesticides at a concentration of 0.3 ng/g of each analyte. The suggested method was applied to determine the studied organochlorine pesticide residues in various cocoa powders and beans gathered from groceries in Tabriz city (Iran) and aldrin and dichlobenil were found in some of them. 相似文献
948.
Use of citric acid as a chelating agent and fuel, ammonium nitrate as fuel, boric acid as flux material and silica as supports, CaWO4:Ln3+@SiO2 (Ln = Er and Tm) nanoparticles were synthesized via a combustion reaction at 800 °C. Characterization of the samples was performed by X-ray diffractometer (XRD), reflectance UV–Vis spectrophotometer, fluorescence spectrophotometer (PL) and transmission electron microscope (TEM). XRD patterns showed that tetragonal crystalline structure of scheelite and silica supports were formed, and that the formation of a silica support could enhance the luminescence intensity of CaWO4:Ln3+. The reflectance UV–Vis and PL spectra indicated the broad absorption band of WO4 2? groups about 240 nm, the WO4 2? wide excitation band with maximum at 240 nm, a broad emission band of WO4 2? with maximum about 420 nm, and characteristic emissions of Ln3+ ions. According to the TEM analysis, CaWO4:Er3+@SiO2 and CaWO4:Tm3+@SiO2 nanoparticles have almost the same morphology with average particle sizes about 50 nm. 相似文献
949.
Muhammad Tariq Saqib Ali Muhammad Nawaz Tahir Nasir Khalid Jafir Hussain Shirazi 《Journal of the Iranian Chemical Society》2014,11(3):839-846
A series of six organotin(IV) carboxylates [Me2SnL2] (1), [n-Bu2SnL2] (2), [n-Oct2SnL2] (3), [Me3SnL] (4), n-Bu3SnL (5) and [Ph3SnL] (6), where L = 3-(4-cyanophenyl) acrylic acid have been synthesized and characterized by elemental analysis, FT-IR and NMR (1H, 13C). The complex (4) was also analyzed by single crystal X-ray analysis which showed distorted trigonal bipyramidal geometry with polymeric bridging behavior. The complexes 1–6 were screened for antimicrobial activities and cytotoxicity. The results showed significant activity with few exceptions. The catalytic activity of complexes was assessed in transesterification reaction of Brassica campestris oil (triglycerides) to produce biodiesel (fatty acid methyl esters). The results showed that triorganotin(IV) complexes exhibited good catalytic activity than their di-analogues. 相似文献
950.
G. Abbas Mariya-al-Rashida A. Irfan U. Ali Rana I. Shakir 《Journal of Structural Chemistry》2014,55(1):30-37
Density functional theory (DFT) is used to investigate the structural properties of Ni(II) cubane [Ni4(ampdH)4Cl4]·MeCN. The structural features and ground state geometry calculations are computed at the B3LYP/6-31G* (LANL2DZ) level of theory. We shed light on the highest occupied molecular orbital and lowest unoccupied molecular orbital. The absorption spectrum is calculated using time-dependent DFT. The absorption wavelengths are calculated using different functionals, i.e., pw91pw91, B3LYP, BHandHLYP, CAM-B3LYP, LC-BLYP, and M06. The LC-BLYP is in good agreement with the experimental data. 相似文献