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91.
Tougerti A Llorens I D'Acapito F Fonda E Hazemann JL Joly Y Thiaudière D Che M Carrier X 《Angewandte Chemie (International ed. in English)》2012,51(31):7697-7701
Surface-dependent precipitation: The adsorption of Ni(II) complexes in aqueous solution on (0001) and (1102) α-Al(2)O(3) single-crystal surfaces has been studied (see the X-ray absorption spectra obtained for parallel and perpendicular polarization directions). The use of planar model systems emphasizes the crucial role of the Al(2)O(3) orientation for Ni dispersion with practical implications in catalyst preparation procedures. 相似文献
92.
Wansi JD Wandji J Mbaze Meva'a L Kamdem Waffo AF Ranjit R Khan SN Asma A Iqbal CM Lallemand MC Tillequin F Fomum Tanee Z 《Chemical & pharmaceutical bulletin》2006,54(3):292-296
The CH2Cl2/MeOH extract of the stem bark of Oriciopsis glaberrima ENGL. afforded four new acridone alkaloids namely oriciacridone C, D, E and F along with six known compounds: atalaphyllidine, oleanolic acid, butulinic acid, beta-sitosterol, stigmasterol, glucoside of stigmasterol and one synthetically known acridone: 1,3,5-trihydroxy-4-prenylacridone. The structures were established on the basis of MS, 1D and 2D NMR experiments. The acridones 1, 4 and 5 showed potent activity against alpha-glucosidase, while the acridones 1-5 showed moderate free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH). 相似文献
93.
A new approach to decoupling of bacterial adhesion energies measured by AFM into specific and nonspecific components 总被引:1,自引:0,他引:1
A new method to decoupling of bacterial interactions measured by atomic force microscopy (AFM) into specific and nonspecific components is proposed. The new method is based on computing the areas under the approach and retraction curves. To test the efficacy of the new method, AFM was used to probe the repulsion and adhesion energies present between Listeria monocytogenes cells cultured at five pH values (5, 6, 7, 8, and 9) and silicon nitride (Si3N4). Overall adhesion energy was then decoupled into its specific and nonspecific components using the new method as well as using Poisson statistical approach. Poisson statistical method represents the most commonly used approach to decouple bacterial interactions into their components. For all pH conditions investigated, specific energies dominated the adhesion, and a transition in adhesion and repulsion energies for cells cultured at pH 7 was observed. When compared, the differences in the specific and nonspecific energies obtained using Poisson analysis and the new method were on average 2.2 % and 6.7 %, respectively. The relatively close energies obtained using the two approaches demonstrate the efficacy of the new method as an alternative way to decouple adhesion energies into their specific and nonspecific components. 相似文献
94.
JPC – Journal of Planar Chromatography – Modern TLC - A thin-layer chromatographic system comprising of silica gel as stationary phase and 1.0% aqueous urea solution as mobile phase (pH... 相似文献
95.
Montazer M Behzadnia A Pakdel E Rahimi MK Moghadam MB 《Journal of photochemistry and photobiology. B, Biology》2011,103(3):207-214
In this study an effective nanocomposite antimicrobial agent for wool fabric was introduced. The silver loaded nano TiO(2) as a nanocomposite was prepared through UV irradiation in an ultrasonic bath. The nanocomposite was stabilized on the wool fabric surface by using citric acid as a friendly cross-linking agent. The treated wool fabrics indicated an antimicrobial activity against both Staphylococcus aureus and Escherichia coli bacteria. Increasing the concentration of Ag/TiO(2) nanocomposite led to an improvement in antibacterial activities of the treated fabrics. Also increasing the amount of citric acid improved the adsorption of Ag/TiO(2) on the wool fabric surface leading to enhance antibacterial activity. The EDS spectrum, SEM images, and XRD patterns was studied to confirm the presence of existence of nanocomposite on the fabric surface. The role of both cross-linking agent and nanocomposite concentrations on the results was investigated using response surface methodology (RSM). 相似文献
96.
Let ? be a prime ring, 𝒞 the extended centroid of ?, ? a Lie ideal of ?, F be a nonzero generalized skew derivation of ? with associated automorphism α, and n ≥ 1 be a fixed integer. If (F(xy) ? yx) n = 0 for all x, y ∈ ?, then ? is commutative and one of the following statements holds: (1) Either ? is central; (2) Or ? ? M 2(𝒞), the 2 × 2 matrix ring over 𝒞, with char(𝒞) = 2. 相似文献
97.
Let R be a ring with center Z(R). An additive mapping ${F : R \longrightarrow R}$ is said to be a generalized derivation on R if there exists a derivation ${d : R \longrightarrow R}$ such that F(xy) = F(x)y + xd(y), for all ${x, y \in R}$ (the map d is called the derivation associated with F). Let R be a semiprime ring and U be a nonzero left ideal of R. In the present note we prove that if R admits a generalized derivation F, d is the derivation associated with F such that d(U) ≠ (0) then R contains some nonzero central ideal, if one of the following conditions holds: (1) R is 2-torsion free and ${F(xy) \in Z(R)}$ , for all ${x, y \in U}$ , unless F(U)U = UF(U) = Ud(U) = (0); (2) ${F(xy) \mp yx \in Z(R)}$ , for all ${x,y \in U}$ ; (3) ${F(xy) \mp [x,y] \in Z(R)}$ , for all ${x,y \in U}$ ; (4) F ≠ 0 and F([x,y]) = 0, for all ${x, y \in U}$ , unless Ud(U) = (0); (5) F ≠ 0 and ${F([x, y]) \in Z(R)}$ , for all ${x, y \in U}$ , unless either d(Z(R))U = (0) or Ud(U) = (0)n. 相似文献
98.
Dr. Akhtar Munir Tanveer ul Haq Iqtidar Hussain Irfan Ullah Syed Zajif Hussain Dr. Ahsanulhaq Qurashi Dr. Javed Iqbal Dr. Asma Rehman Prof. Dr. Irshad Hussain 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(49):11209-11219
The use of water splitting modules is highly desired for the sustainable production of H2 as a future energy carrier. However, the sluggish kinetics and demand of high anodic potential are the bottlenecks for half-the cell oxygen evolution reaction (OER), which severely hamper the overall conversion efficiency. Although transition metal oxides based electrocatalysts have been envisioned as cost-effective and potential contenders for this quest, nevertheless, their low conductivity, instability, and limited number of active sites are among the common impediments that need to be addressed to eventually enhance their inherent catalytic potential for enhanced OER activity. Herein, the controlled assembly of transition metal oxides, that is, Cu@CuOx nanoclusters (NCs, ≈2 nm) and Co@CoOx beaded nanoclusters (BNCs, ≈2 nm), on thiol-functionalized graphene oxide (G-SH) nanosheets is reported to form novel and highly efficient electrocatalysts for OER. The thiol (-SH) functionality was incorporated by selective epoxidation on the surface of graphene oxide (GO) to achieve chemically exfoliated nanosheets to enhance its conductivity and trapping ability for metal oxides in nanoscale dimensions (≈2 nm). During the electrocatalytic reaction, overpotentials of 290 mV and 310 mV are required to achieve a current density of 10 mA cm−2 for BNCs and NCs, respectively, and the catalysts exhibit tremendous long-term stability (≈50 h) in purified alkaline medium (1 m KOH) with no dissolution in the electrolyte. Moreover, the smaller Tafel slopes (54 mV/dec for BNCs and 66 mV/dec for NCs), and a Faradic efficiency of approximately 96 % indicate not only the selectivity but also the tailored heterogeneous electrons transfer (HET) rate, which is required for fast electrode kinetics. It is anticipated that such ultrasmall metal oxide nanoclusters and their controlled assembly on a conducting surface (G-SH) may offer high electrochemical accessibility and a plethora of active sites owing to the drastic decrease in dimensions and thus can synergistically ameliorate the challenging OER process. 相似文献
99.
Wedad A. Al-Onazi Amal M. Al-Mohaimeed Zainab M. Almarhoon Eida S. Al-Farraj Asma A. Alothman 《中国化学会会志》2020,67(1):125-134
A potentiometric method was used to determine the stability constants for the various complexes of copper(II) with carbamoylcholine chloride (C) drug as a ligand in the presence of some biorelevant amino acid constituents like glycine (Gly), alanine (Ala), valine (Val), proline (Pro), β-phenylalanine (Phe), S-methylcysteine (Met), threonine (Thr), ornithine (Orn), lysine (Lys), histidine (Hisd), histamine (Hist), and imidazole (Imz) as ligands (L). Stability constants of complexes were determined at 25°C and I = 0.10 mol/L NaNO3. The relative stability of each ternary complex was compared with that of the corresponding binary complexes in terms of Δlog K and % R.S. values. Cu(II) complexes of drug C were synthesized in 1:1 and 1:1:1 M ratios of copper to drug [Cu(C)(NO3)2] (1) and copper to drug to glycine[Cu(C)(Gly)(NO3)].NO3 (2), respectively. Glycine ternary complex with drug and copper [Cu(C)(Gly)(NO3)].NO3 was considered as representative amino acid. The complexes 1 and 2 were isolated and characterized using various physicochemical and spectral techniques. Both complexes 1 and 2 were found to have magnetic moments corresponding to one unpaired electron. The possible square planar and square-pyramidal geometries of the copper (II) complexes were assigned on the basis of electron paramagnetic resonance (EPR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), ultraviolet–visible (UV–Vis) and infrared (IR) spectral studies, and the discrete Fourier transform method from DMOL3 calculations. Antioxidant activities of all the synthesized compounds were also investigated. 相似文献
100.
In the search of effective bioactive compounds, Co(II) ( C1 ) and Cd(II) ( C2 ) complexes of the type [M(FMAPIMP)(H2O)Cl].nH2O (where M = Co(II); n = 2, Cd(II); n = 3, and FMAPIMP = ligand[2-((E)-((2-(((E)-furan-2-ylmethylene)amino)phenyl)imino)methyl)phenol]) were synthesized and characterized using elemental analysis, UV–Vis., cyclic voltammetry, Fourier-transform infrared (FT-IR), nuclear magnetic resonance, and mass spectral studies. The thermal stability of nano-sized Co(II) and Cd(II) complexes was studied using thermogravimetric analysis (TGA). Cobalt and cadmium oxides were synthesized using cobalt and cadmium nanoparticle (NP) structure Schiff base complexes as the raw material after calcination for 5 h at 600 °C. According to the results, Co(II) and Cd(II) complexes with mole ratio 1:1 of metal: H-FMAPIMP which octahedral are the most probable geometry for it. On the contrary, synthesized C1 and C2 NPs were used as suitable precursors for the preparation of CoO and CdO NPs. The obtained NPs were characterized using FT-IR, UV–Vis., TGA, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy techniques. PXRD analysis revealed that the obtained oxides were crystalline and corresponded to CoO and CdO phases. Crystal size, shape, and morphology were determined using SEM and TEM. H-FMAPIMP and its two complexes ( C1 and C2 ) were tested against human ovarian cancer cell line (PA-1). The synthesized Co(II) and Cd(II) complexes exhibited enhanced activity against the tested bacterial (Staphylococcus aureus and Escherichia Coli) and fungal strains (Candida albicans and Aspergillus fumigatus) as compared to H-FMAPIMP. The results of the DNA-cleavage activity indicated that the ligand and its two complexes can cleave calf thymus-DNA at different degrees. Further, antituberculosis activity was performed using microplate alamarBlue assay. Among all these synthesized compounds, C1 exhibited good cleaving ability compared to the newly synthesized C2 . Finally, the geometry of H-FMAPIMP and its Co(II) and Cd(II) complexes was optimized using molecular modeling. 相似文献