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11.
Visually evoked intrinsic optical signals (IOSs) were measured in vivo for the first time to our knowledge from all retina layers of the chicken retina with a combined functional optical coherence tomography and electroretinography (ERG) system. IOS traces were recorded from a small volume in the retina with 3.5 μm axial resolution and 7 ms time resolution. Comparison of the IOS and ERG traces shows a correlation between the positive and negative IOS measured from different retinal layers and the timing of the a and b waves in the ERG recording. 相似文献
12.
To screen one-bead-one-compound (OBOC) combinatorial bead libraries,(1) one generally uses tagged purified protein as the screening probe. Compound beads that interact with the purified protein are then identified, for example, via an enzyme-linked colorimetric assay, and isolated for structure determination. In this report, we demonstrate a rapid and efficient method to screen OBOC combinatorial libraries utilizing two protein mixtures as screening probes, and by comparing optical images of the beads stained by one protein mixture but not the other, ligand beads unique to one of the two protein mixtures can be identified. The significance of this method is that it allows for rapid selection of ligands directed against proteins unique to one mixture while screening out positive beads resulting from proteins common to both mixtures as well as beads that are positive as a result of interactions with chemical and protein components found in the assay itself. The method is fast, efficient, and uses off-the-shelf equipment. 相似文献
13.
Sepideh Afsari Parisa Yasini Haowei Peng John P. Perdew Eric Borguet 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(40):14413-14418
In most junctions built by wiring a single molecule between two electrodes, the electrons flow along only one axis: between the two anchoring groups. However, molecules can be anisotropic, and an orientation‐dependent conductance is expected. Here, we fabricated single‐molecule junctions by using the electrode potential to control the molecular orientation and access individual elements of the conductivity tensor. We measured the conductance in two directions, along the molecular plane as the benzene ring bridges two electrodes using anchoring groups (upright) and orthogonal to the molecular plane with the molecule lying flat on the substrate (planar). The perpendicular (planar) conductance is about 400 times higher than that along the molecular plane (upright). This offers a new method for designing a reversible room‐temperature single‐molecule electromechanical switch that controllably employs the electrode potential to orient the molecule in the junction in either “ON” or “OFF” conductance states. 相似文献
14.
Khadijeh Ghanbari Sepideh Bonyadi 《International Journal of Polymer Analysis and Characterization》2020,25(3):105-125
AbstractIn this study, the Pt nanoparticles/over-oxidized polypyrrole nanofiber/reduced graphene oxide (Pt NPs/OPPy/RGO) nanocomposite was electrochemically synthesized and used to modify a glassy carbon electrode. To confirm the Surface morphology and characterization of the nanocomposite, field emission scanning microscopy (FE-SEM), X-ray diffraction (XRD), Raman, FT-IR, and X-ray photoelectron spectroscopy (XPS) were used. Simultaneous determination of these species showed one linear response 0.1–250.0?μM and two linear responses 0.5–10.0?μM and 10.0–470.0?μM, with detection limits 42?nM and 106?nM (S/N?=?3) for DA and 5-HT, respectively. Finally, the analytical application of this modified electrode was investigated in the human blood plasma. 相似文献
15.
Kojabad Zohreh Deljoo Shojaosadati Seyed Abbas Firoozabadi Seyed Mohammad Hamedi Sepideh 《Journal of Solid State Electrochemistry》2019,23(5):1533-1539
Journal of Solid State Electrochemistry - High selectivity and low impedance are preferred properties for neural microelectrodes. The localized and controlled release of drugs from the... 相似文献
16.
Mohammad Mahdi Zangeneh Shabnam Bovandi Sepideh Gharehyakheh Akram Zangeneh Parisa Irani 《应用有机金属化学》2019,33(7)
Allium saralicum R.M. Fritsch has been used in Iranian traditional medicine as a remedial supplement for microbial diseases. This paper reports the green synthesis, chemical characterization and antioxidant, cytotoxic, antibacterial and antifungal properties of silver nanoparticles obtained using aqueous extract of A. saralicum leaves. In this synthesis, no surfactants or stabilizers were used. For characterization, UV–visible spectroscopy, transmission electron microscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy and field emission scanning electron microscopy were used. 2,2‐Diphenyl‐1‐picrylhydrazyl was used in experiments to assess the antioxidant potential of the silver nanoparticles, which revealed an impressive prevention in comparison with butylated hydroxytoluene. The synthesized silver nanoparticles at low doses (1–250 μg dl?1) did not show marked cytotoxic activity (against cervical cancer cells (Hela), breast cancer cells (MCF‐7) and human embryonic kidney cells (HEK‐293)). Agar diffusion tests were applied to determine the antibacterial and antifungal characteristics. Compared with all standard antimicrobials, the silver nanoparticles showed higher antibacterial and antifungal activities (p ≤ 0.01). Also, the silver nanoparticles inhibited the growth of all bacteria and fungi at concentrations of 31–250 μg ml?1, and destroyed them at concentrations of 31–500 μg ml?1 (p ≤ 0.01). Because the silver nanoparticles obtained using aqueous extract of A. saralicum leaves have antioxidant, non‐cytotoxic, antifungal and antibacterial potentials, they can be used as a medical supplement or drug. 相似文献
17.
In this study, a new polymeric functionalized magnetic nanocatalyst containing a molybdenum Schiff base complex was prepared using a few consecutive steps. Poly (methylacrylate)-coated magnetic nanoparticles were synthesized via radical polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the amidation of the methyl ester groups with hydrazine. Polymeric functionalization efficiently provides the advantage that more catalytic units can be grafted on the surface of magnetic nanoparticles. The functionalization process was continued with salicylaldehyde which introduced Schiff base groups on to the surface of the polymeric support. In the final step, the desired catalytic system was prepared via complexation of the Schiff base groups with MoO2(acac)2. The resulting nanoparticles were characterized by infrared spectroscopy, powder X-ray diffraction, scanning and transmission electron microscopy, elemental analysis, inductively coupled plasma optical emission spectrometry, vibrating sample magnetometry and thermogravimetric analysis. This heterogenized catalytic system was also found to be highly active, sustainable and recyclable nanocatalyst in alkene epoxidation. Eventually, the attractive features of the synthesized catalyst such as simple work-up, good stability, magnetic separation, high TOF and high surface area; make it appropriate for oxidation reactions. 相似文献
18.
Sepideh Maaref 《Journal of Dispersion Science and Technology》2018,39(5):721-733
Water-in-oil emulsion usually forms during waterflooding in some heavy oil reservoirs. The composition and salinity of the injected water critically affect the w/o emulsion droplet size distribution, which control the emulsion stability and emulsion flow in porous media. The aim of the present work is to assess the effect of different sea water salinities on w/o emulsion stability through microscopic imaging. Therefore, w/o emulsions were prepared with different sea water samples, which were synthesized to resemble Persian Gulf, Mediterranean, Red Sea, and North Sea water samples. The results showed that log-normal distribution function predicts very well the experimental data to track the emulsion droplet size distribution, and then it was used for the emulsion stability analysis. It was found that among the four emulsion samples, North Sea emulsion with the lowest NaCl and TDS concentration of 24.12?g/L and 34.44?g/L remained stable up to almost 24 hours, while Red sea emulsion with the highest NaCl and TDS concentration of 32.39?g/L and 41?g/L became unstable after 6-hour period. This indicated that as the brine concentration increases, the w/o emulsion droplets would be larger due to the higher rate of aggregation and coalescence, and the emulsion stability decreases. 相似文献
19.
Utilizing pure amine hydrogen bonding is a novel approach for constructing two‐dimensional (2D) networks. Further, such systems are capable of undergoing structural modifications due to changes in pH. In this study, we designed a 2D network of triaminobenzene (TAB) molecules that by varying the pH from neutral to acidic, form either ordered or disordered structures on Au(111) surface as revealed in scanning tunneling microscopy images. In near‐neutral solution (pH ≈5.5), protonation of TAB generates charged species capable of forming H‐bonds between amine groups of neighboring molecules resulting in the formation of a 2D supramolecular structure on the electrified surface. At lower pH, due to the protonation of the amine groups, intermolecular hydrogen bonding is no longer possible and no ordered structure is observed on the surface. This opens the possibility to employ pH as a chemical trigger to induce a phase transition in the 2D molecular network of triaminobenzene molecules. 相似文献
20.
Shadpour E. Mallakpour Abdol‐Reza Hajipour Ali‐Reza Mahdavian Sepideh Khoee 《Journal of polymer science. Part A, Polymer chemistry》1999,37(8):1211-1219
The reaction of N‐phthaloyl‐L ‐leucine acid chloride (1) with isoeugenol (2) was carried out in chloroform, and novel optically active isoeugenol ester derivative 3 as a chiral monomer was obtained in high yield. Compound 3 was characterized by 1H‐NMR, IR, and mass and elemental analysis and then was used for the preparation of model compound 5 and polymerization reactions. 4‐Phenyl‐1,2,4‐triazoline‐3,5‐dione, PhTD (4), was allowed to react with compound 3. The reaction is very fast and gives only one diastereomer of 5 via Diels–Alder and ene pathways in quantitative yield. In order to explain this diastereoselectivity, a nonconcerted two‐step mechanism involving benzylic cation (BC) and aziridinium (AI) have been proposed for the Diels–Alder and ene reactions, respectively. The polymerization reactions of novel monomer 3 with bis(triazolinedione)s [bis(p‐3,5‐dioxo‐1,2,4‐triazolin‐4‐ylphenyl)methane (8) and 1,6‐bis(3,5‐dioxo‐1,2,4‐triazolin‐4‐yl)hexane] (9)] were performed in N,N‐dimethylacetamide (DMAc) at room temperature. The reactions are exothermic, fast, and gave novel optically active polymers 10 and 11 via repetitive Diels–Alder–ene polyaddition reactions. These polymers have inherent viscosities in a range about 0.18–0.22 dL/g. Some physical properties and structural characterizations of these new polymers have been studied and are reported. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1211–1219, 1999 相似文献