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191.
Jatinder Kaur Atul Bhardwaj Frank Wuest 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(10):3326-3337
Live-cell imaging with fluorescent probes is an essential tool in chemical biology to visualize the dynamics of biological processes in real-time. Intracellular disease biomarker imaging remains a formidable challenge due to the intrinsic limitations of conventional fluorescent probes and the complex nature of cells. This work reports the in cellulo assembly of a fluorescent probe to image cyclooxygenase-2 (COX-2). We developed celecoxib-azide derivative 14 , possessing favorable biophysical properties and excellent COX-2 selectivity profile. In cellulo strain-promoted fluorogenic click chemistry of COX-2-engaged compound 14 with non/weakly-fluorescent compounds 11 and 17 formed fluorescent probes 15 and 18 for the detection of COX-2 in living cells. Competitive binding studies, biophysical, and comprehensive computational analyses were used to describe protein-ligand interactions. The reported new chemical toolbox enables precise visualization and tracking of COX-2 in live cells with superior sensitivity in the visible range. 相似文献
192.
Dr. Eoghan G. Delany Satnam Kaur Prof. Steven Cummings Dr. Kristoffer Basse Dr. David J. D. Wilson Dr. Jason L. Dutton 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(20):5298-5302
Although ultimately not isolable for X-ray structural characterization, the free perfluorinated trityl cation was shown to be observable in neat triflic acid, which represents milder conditions than previous reports of this cation in “magic acid” or oleum. A triflate-bound species could be generated in organic solvents using stoichiometric amounts of triflic acid and was shown to be synthetically viable for hydride abstraction from Et3SiH. It was demonstrated that the para-position on the -C6F5 rings is the primary point of attack for decomposition of the cation. 相似文献
193.
Dr. Francesca Limosani Ramandeep Kaur Dr. Antonino Cataldo Dr. Stefano Bellucci Federico Micciulla Prof. Robertino Zanoni Dr. Angelo Lembo Dr. Bingzhe Wang Prof. Roberto Pizzoferrato Prof. Dirk M. Guldi Prof. Pietro Tagliatesta 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23914-23923
A novel family of nanocarbon-based materials was designed, synthesized, and probed within the context of charge-transfer cascades. We integrated electron-donating ferrocenes with light-harvesting/electron-donating (metallo)porphyrins and electron-accepting graphene nanoplates (GNP) into multicomponent conjugates. To control the rate of charge flow between the individual building blocks, we bridged them via oligo-p-phenyleneethynylenes of variable lengths by β-linkages and the Prato–Maggini reaction. With steady-state absorption, fluorescence, Raman, and XPS measurements we realized the basic physico-chemical characterization of the photo- and redox-active components and the multicomponent conjugates. Going beyond this, we performed transient absorption measurements and corroborated by single wavelength and target analyses that the selective (metallo)porphyrin photoexcitation triggers a cascade of charge transfer events, that is, charge separation, charge shift, and charge recombination, to enable the directed charge flow. The net result is a few nanosecond-lived charge-separated state featuring a GNP-delocalized electron and a one-electron oxidized ferrocenium. 相似文献
194.
From the alcoholic fraction of North Indian vetiver oil () a new C14 terpenoid, norkhusinoloxide has been isolated. Stereostructure has been assigned to it on the basis of chemical correlation coupled with spectral data. This stereostructure was further confirmed on the basis of the comparison of its plant growth activity with that displayed by khusinol oxide of known stereostructure. It is the first report where biological evaluation has been used as a tool to confirmstereo structure of a naturally occurring terpenoid. 相似文献
195.
Jagbir Singh Harjeet Kaur A. Sharma J. Goswamy D. Mehta Nirmal Singh P. N. Trehan E. S. Paul R. K. Bhowmik 《Zeitschrift für Physik A Hadrons and Nuclei》1986,356(2):125-132
High spin states of 121Te, populated in the 114Cd (11B, p3n) reaction, have been studied through γ-ray spectroscopy. The level scheme has been established up to Jπ = 51/2?. Three-quasiparticle states, based on the πg 7/2 2 ? vh11/2 and πg 7/2d5/2 ? vh11/2 configurations, have been identified. A favoured 39/2? state is suggested to be the fully aligned [πg7/2 2]6 + ? [vh 11/2 3]27/2? yrast non-collective oblate configuration. This assignment is supported by Total Routhian Surface (TRS) calculations which also suggest a similar oblate assignment to the states at Jπ = 21/2? and 23/2?. A higher 47/2? state is also found and is suggested to be the fully aligned [πg7/2 2]6+ ? [vh 11/2 5]35/2? configuration. 相似文献
196.
Balwinder Kaur Monita Bhat F. Licci Ravi Kumar S.D. Kulkarni P.A. Joy K.K. Bamzai P.N. Kotru 《Journal of magnetism and magnetic materials》2006
Using vibrating sample magnetometery (VSM) 50 MeV Li3+ ion irradiation effects on magnetic properties of single crystals of SrGaxInyFe12−(x+y)O19 (where x=0, 5, 7, 9; y=0, 0.8, 1.3, 1.0), are reported. The substitution of Ga and In in strontium hexaferrite crystals decreases the value of magnetization sharply, which is attributed to shifting of collinear magnetic order to a non-collinear one. Reduction of magnetization is also explained to be as a result of the occupation of the crystallographic sites of Fe3+ by Ga3+ and In3+. The Li3+ ion irradiation decreases the value of magnetization, irrespective of whether the crystals are Ga–In substituted or unsubstituted crystals of SrFe12O19. The result is interpreted in terms of the occurrence of a paramagnetic doublet in crystals replacing magnetic sextuplet as a result of irradiation. Substitution of Ga–In in Strontium hexaferrite decreases the value of anisotropy constant. Irradiation with Li3+ ions increases the values of anisotropy field for both substituted as well as unsubstituted crystals. Substitution with Ga–In also decreases the Curie temperature (Tc) but the irradiation with Li3+ ions does not affect the curie temperature of either Ga–In substituted or pure SrFe12O19 crystals. 相似文献
197.
K. S. Dhillon Rupinder Kaur K. Singh 《Journal of Radioanalytical and Nuclear Chemistry》1991,154(6):413-419
The - sum peak method based on the phenomenon of perturbed angular correlation has been applied to see the effect of chemical environment on the directional correlation coefficients of various cascades and to check the suitability of160Tb as a probe. No change in sum peak intensity ratios for different pH and gelatin concentration values have been seen. 相似文献
198.
Amarjot Kaur Harshinder Singh 《Annals of the Institute of Statistical Mathematics》1991,43(2):347-356
Let random samples of equal sizes be drawn from two exponential distributions with ordered means
i
. The maximum likelihood estimator
i
* of
i
is shown to have a smaller mean square error than that of the usual estimator Xi, for each i=1,2. The asymptotic efficiency of
i
* relative to Xi has also been found. 相似文献
199.
Duong Duc La Anuradha Anuradha Amanpreet Kaur Hundal Sidhanath V. Bhosale Lathe A. Jones 《Supramolecular chemistry》2018,30(1):1-8
The fabrication of well-defined nanostructures with luminescent properties in the solid or aggregated state is of intense interest due to their applications in nano- and biotechnology. We report the synthesis of water-soluble tetraphenylethylene bearing four sulfonate groups as a sodium salt (Su-TPE), and investigations concerning its AIE characteristics by the addition of organic solvent into the aqueous solution, which is the reverse procedure to conventional AIE-active TPE derivatives. The resultant compound is weakly emissive in pure water, however, emits strongly upon addition of THF solvent (with THF fraction > 60%). The emission properties and the morphologies of the aggregates were greatly dependent upon the solution pH. Su-TPE self-assembled into variety of structures in water/THF mixture with pH control, for the first time. Well-defined uniform nanorods with a width of about 200 nm and a length of up to 10 μm were obtained at solution pH of 1. The Su-TPE showed very good mechanochromic properties were observed during the process of grounding and fuming. 相似文献
200.
Navjeet Kaur 《合成通讯》2018,48(11):1259-1284
The chemists have been interested in light as an energy source to induce chemical reactions since the beginning of scientific chemistry. This review summarizes the chemistry of photochemical reactions with emphasis of their synthetic applications. The organic photochemical reactions avoid the polluting or toxic reagents and therefore offer perspectives for sustainable processes and green chemistry. In summary, this review article describes the synthesis of a number of five-membered N-heterocycles. 相似文献