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971.
In this paper, we propose a novel ultra-compact nanoplasmonic coupler using gallium lanthanum sulfide (GLS) which yields an efficiency of 67% at the optical communication wavelength. The analysis has been done numerically using the finite-difference time-domain method. Our proposed coupler can operate at a broad frequency range and easier to fabricate than couplers with multi-section tappers since it is a simple rectangular-shaped coupler with no variation along the whole length. 相似文献
972.
Idris Cerkez Hasan B. Kocer S. D. Worley R. M. Broughton T. S. Huang 《Cellulose (London, England)》2012,19(3):959-966
Three heterocyclic N-halamine structures containing amine, amide, or both functional groups were immobilized onto cotton fabric through epoxide tethering. The coatings were rendered biocidal upon exposure to dilute household bleach solution. The coatings exhibited superior biocidal functionality with complete inactivation of about 6 logs of Staphylococcus aureus and Escherichia coli O157:H7 within 2–10 min contact time depending on the structure. Moreover, the coatings were quite stable against repeated laundering so that recharging was not even necessary after 50 washing cycles. Stability of the coatings against ultraviolet light exposure was studied with a comparison of the amide- and amine-containing N-halamines. 相似文献
973.
Tri-iso-amyl phosphate (TAP): An alternative extractant to tri-butyl phosphate (TBP) for reactor fuel reprocessing 总被引:1,自引:0,他引:1
Tri-iso-amyl phosphate (TAP), an indigenously prepared extractant was utilized for reactor fuel reprocessing and compared with tri-butyl phosphate (TBP) and tri-n-hexyl phosphate (THP). The potential of these extractants was found to be in the order TAP>THP>TBP by calculating the acid uptake value (K
H). The effect of various parameters such as solvent degradation due to acid hydrolysis, radiation effect, decontamination factor and phase separation were investigated and it was found that TAP was always a better extractant in comparison to THP and TBP. In addition to this, the extraction of fission product contaminants such as 144Ce, 137Cs, 106Ru, 95Zr was almost negligible, even at very high nitric acid concentrations in the aqueous phase, indicating the potential application of TAP in actinide partitioning. Sodium carbonate solution or acidified distilled water was a good strippant for U(VI), similarly, uranium(IV) nitrate stripped Pu(IV) from the organic phase. 相似文献
974.
Meryem Fistikci Ozlem Gundogdu Derya Aktas Hasan Secen M. Fethi Sahin Ramazan Altundas Yunus Kara 《Tetrahedron》2012,68(12):2607-2610
A new synthetic strategy for (R)- and (S)-3-hydroxy-4-(2,4,5-trifluorophenyl)butanoic acid, a building block in the preparation of sitagliptin and its derivatives, was developed. Pd(OAc)2 catalyzed coupling of 2,4,5-trifluoro-1-iodobenzene with allyl alcohol gave 3-(2,4,5-trifluorophenyl)propanal in a yield of 95%. l-Proline catalyzed reaction of the 3-phenylpropanal (in only 1.2 molar equiv) with nitrosobenzene followed by reduction with NaBH4 and Pd/C catalyzed hydrogenation gave (R)-3-(2,4,5-trifluorophenyl)propane-1,2-diol with >99% ee and 65% yield. Selective tosylation of primary hydroxyl group of the 1,2-propandiol unit followed by cyanide displacement afforded (R)-3-hydroxy-4-(2,4,5-trifluorophenyl)butanenitrile (80%). The nitrile was converted to the title β-hydroxy acid under basic hydrolysis in a yield of 90%. Thus, (R)-3-hydroxy-4-(2,4,5-trifluorophenyl)butanoic acid was prepared enantioselectively from the starting material in four steps and 45% overall yield. The reaction sequence was repeated with d-proline as the catalyst to give (S)-3-hydroxy-4-(2,4,5-trifluorophenyl)butanoic acid in 45% overall yield and >99% enantiomeric excess. 相似文献
975.
Ultraviolet (UV) radiation from the solar spectrum is a major etiological factor for many cutaneous pathologies including cancer. By understanding changes in cell signaling pathways induced by UVA and UVB, novel strategies for prevention and treatment of UV‐related pathologies could be developed. However, much of the information in the literature from various laboratories cannot cross talk because of difficulties associated with the use of ill‐defined light sources and physiologically irrelevant light dosimetry. Herein, we have assessed the effect of exposure of normal human epidermal keratinocytes (NHEK) to UVA (2 and 4 J cm?2) or UVB (20 and 40 mJ cm?2) radiation. Employing western blot analysis, we found that exposure of NHEK to UVB, but not UVA, phosphorylates JNK1/2 at Th183/Tyr185, STAT3 at Ser727, AKT at Ser473 and increases c‐Fos expression, whereas exposure to UVA, but not UVB, phosphorylates AKT at Thr308. UVB as well as UVA exposure leads to increased phosphorylation of (1) ERK1/2 at Th202/Tyr204; (2) p38 at Th180/Tyr204; (3) STAT3 at Tyr705; (4) mTOR at Thr2448; and (v) p70S6k at Thr421/Ser424; enhanced expression of PI3K (p85) and c‐jun; and nuclear translocation of NFκB proteins. These findings could be considered as a beginning for understanding the differential effects of UVA and UVB in the human skin and may have implications both with respect to risk assessment from exposure to solar UV radiation, and to target interventions against signaling events mediated by UVA and UVB. 相似文献
976.
Parviz Norouzi Mohammad Reza Ganjali Rassoul Dinarvand Mohammad Hasan Eshraghi Hassan Ali Zamani 《Russian Journal of Electrochemistry》2010,46(9):999-1006
The determination of prilocain, used to manage tonic-clonic seizures, has been carried out at micro gold electrode (Au UME)
using continuous fast Fourier transform square wave voltammetry. The Au UME electrode exhibited an effective response towards
prilocaine adsorption. The peak current was also found to be significantly increased. The determination was carried out in
phosphate containing electrolyte in the pH of 2.0 and a well-defined change on the peak current were noticed. The peak current
was found to be linearly dependent on concentration of prilocain in the concentration range 5.0 × 10−7–1.0 × 10−11 M with a detection limit of 5.0 × 10−12 M. This paper describes development of a new analysis system to determine of prilocain by a novel square wave voltammetry
method to perform a very sensitive method. The method used for determination of prilocain by measuring the changes in admittance
voltammogram of a gold ultramicroelectrode (in 0.05 M H3PO4 solution) caused by adsorption of the prilocain on the electrode surface. Variation of admittance in the detection process
is created by inhibition of oxidation reaction of the electrode surface, by adsorbed of prilocain. Furthermore, signal-to-noise
ratio has significantly increased by application of discrete Fast Fourier Transform (FFT) method, background subtraction and
two-dimensional integration of the electrode response over a selected potential range and time window. Also in this work some
parameters such as SW frequency, eluent pH, and accumulation time were optimized. The relative standard deviation at concentration
5.0 × 10−8 M is 5.8% for 5 reported measurements. 相似文献
977.
Ahmed Abdullah Fazlul Huq Ashraf Chowdhury Hasan Tayyem Philip Beale Keith Fisher 《BMC chemical biology》2006,6(1):3-9
Background
Cis-planaramineplatinum(II) complexes like their trans isomers are often found to be active against cancer cell lines. The present study deals with the synthesis, characterization and determination of activity of new cis-planaramineplatinum(II) complexes. 相似文献978.
979.
Viktor O. Iaroshenko Sajid AliTariq Mahmood Babar Sergii DudkinSatenik Mkrtchyan Nasim Hasan RamaAlexander Villinger Peter Langer 《Tetrahedron letters》2011,52(3):373-376
4-Chloro-3-(trifluoroacetyl)coumarin was synthesized for the first time via direct TMSCl-mediated acylation of 4-hydroxycoumarin with TFAA followed by the treatment with POCl3. The reaction of 4-chloro-3-(trifluoroacetyl)coumarin with commercially available anilines is a two-step method, which affords a set of 7-(trifluoromethyl)-6H-chromeno[4,3-b]quinolin-6-ones in good to excellent yields. 相似文献
980.
Tariq Mahmood Babar Muhammad Moazzam Naseer Muhammad Khawar Rauf Humayun Pervez Masahiro Ebihara Nasim Hasan Rama 《中国化学快报》2014,25(9):1282-1286
A novel fused isocoumarin skeleton has been synthesized through selective domino multicyclizations by mixing homothallic acid and 2,3-diphenylacryloyl chloride at 200℃ under catalyst and solvent free reaction conditions. Six fused rings with two stereogenic centers were assembled in a convenient onepot operation in good yield. The resulting hexacyclic fused isocoumarin skeleton and its stereochemistry was fully characterized and unambiguously confirmed by X-ray diffraction analysis. 相似文献