排序方式: 共有120条查询结果,搜索用时 15 毫秒
41.
Jagdish S. Thakur Houbei Dai Gulay K. Serhatkulu Ratna Naik Vaman M. Naik Alex Cao Abhilash Pandya Gregory W. Auner Rajah Rabah Michael D. Klein Carl Freeman 《Journal of Raman spectroscopy : JRS》2007,38(2):127-134
Raman spectroscopy involves the interaction of light with the molecular vibrations and therefore can provide information about molecular structure, tissue composition and changes in its environment. We explored whether Raman spectroscopy can reliably distinguish mammary tumors from normal mammary tissues and other pathological states in mice. We analyzed a large number of Raman spectra from the tumor and normal mammary glands of mice injected with 4T1 tumor cells, which were collected using a high‐resolution (less than 4 cm−1) Raman spectrometer at a fixed (785 nm) laser excitation wavelength and with 60 mW of laser power. The spectra of normal and tumor mammary glands showed consistent differences in the intensity of certain Raman bands and loss of some bands in the tumor spectra. Multivariate statistical methods—principal component analysis (PCA) and discriminant functional analysis (DFA)—were used to separate the data into different groups of mammary tumors, mastitis, lymph nodes contralateral and tumor‐cell‐injected sides, and normal contralateral and tumor‐cell‐injected sides. We demonstrate that this spectroscopic technique has the feasibility of discriminating tumor and mastitis from normal tissues and other pathological states in a short period of time and may detect tumor transformation earlier than the standard histological examination stage. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
42.
Alex Cao Abhilash K. Pandya Gulay K. Serhatkulu Rachel E. Weber Houbei Dai Jagdish S. Thakur Vaman M. Naik Ratna Naik Gregory W. Auner Raja Rabah D. Carl Freeman 《Journal of Raman spectroscopy : JRS》2007,38(9):1199-1205
This paper introduces a new robust method for the removal of background tissue fluorescence from Raman spectra. Raman spectra consist of noise, fluorescence and Raman scattering. In order to extract the Raman scattering, both noise and background fluorescence must be removed, ideally without human intervention and preserving the original data. We describe the rationale behind our robust background subtraction method, determine the parameters of the method and validate it using a Raman phantom against other methods currently used. We also statistically compare the methods using the residual mean square (RMS) with a fluorescence‐to‐signal (F/S) ratio ranging from 0.1 to 1000. The method, ‘adaptive minmax’, chooses the subtraction method based on the F/S ratio. It uses multiple fits of different orders to maximize each polynomial fit. The results show that the adaptive minmax method was significantly better than any single polynomial fit across all F/S ratios. This method can be implemented as part of a modular automated real‐time diagnostic in vivo Raman system. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
43.
Davut Avcı Sümeyye Altürk Fatih Sönmez Ömer Tamer Adil Başoğlu Yusuf Atalay Belma Zengin Kurt Necmi Dege 《应用有机金属化学》2020,34(4):e5412
A series of mixed-ligand M(II) complexes containing 1,10-phenanthroline (phen) and 3-methylpyridine-2-carboxylic acid (3-mpaH) or 6-methylpyridine-2-carboxylic acid (6-mpaH), namely [Co(3-mpa)2(phen)]·3H2O ( 1 ), [Hg(6-mpa)2(phen)]·2H2O ( 2 ), [Mn(6-mpa)2(phen)]·2H2O ( 3 ), [Co(6-mpa)2(phen)]·H2O ( 4 ) and [Ni(6-mpa)2(phen)]·H2O ( 5 ), were synthesized for the first time. Among them, 1 was obtained as single crystals. The structural characterization for 1 was conducted using X-ray diffraction and that for 2 – 5 using mass spectrometry. The IC50 values for α-glucosidase inhibition of 1 – 5 were obtained as 0.161 to >600 μM. The spectral properties were also investigated using Fourier transform infrared and UV–visible spectra. Furthermore, to investigate the geometrical parameters, spectral and electronic properties and second- and third-order nonlinear optical parameters for 1 – 5 , density functional calculations were applied. 相似文献
44.
Melnychuk Khrystyna Marchuk Oleg Daszkiewicz Marek Gulay Lubomir 《Structural chemistry》2020,31(5):1945-1957
Structural Chemistry - The crystal structures of quaternary R3Fe0.5SnS7, R3Co0.5SnS7 and R3Ni0.5SnS7 (R = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy and Ho) compounds of La3Mn0.5SiS7 structure type (space... 相似文献
45.
Andreana Marino Gokhan Zengin Antonia Nostro Giovanna Ginestra Paola Dugo Francesco Cacciola 《Natural product research》2016,30(22):2620-2623
The antimicrobial activity of acetone, methanol and aqueous extracts of Asphodeline anatolica E. Tuzlaci leaves was evaluated against American type culture collection, food and clinical isolates (Listeria monocytogenes and Staphylococcus aureus including methicillin-resistant strains-MRSA). Biofilm formation, toxicity and characterisation of the polyphenolic content were analysed. The acetone extract demonstrated a higher antibacterial activity against S. aureus including MRSA strains, L. monocytogenes and Pseudomonas aeruginosa than against other extracts. No effect was observed in biofilm formation. The extracts resulted non-toxic against Artemia salina Leach. The phytochemical screening of extracts indicated that they mainly contained six polyphenols identified as catechin 3-O-gallate, protocatechuic acid, diosmin, rutin, cirsimaritin and kaempferol glucoside. This study is the first report on antimicrobial activity and phenolic content of A. anatolica and contributes to enrich the literature data on the biological properties of this plant. A. anatolica leaves have a potential as source of natural antimicrobial compounds. 相似文献
46.
Gulay Algul Yusuf Ceylan Hacer Yumurtaci Aydogmus Ayhan Usta Biray Asik 《辐射效应与固体损伤》2016,171(5-6):451-460
1H-Benzo[b]pyrrole samples were irradiated in the air with gamma source at 0.969?kGy per hour at room temperature for 24, 48 and 72?h. After irradiation, electron spin resonance, thermogravimetry analysis (TGA) and differential thermal analysis (DTA) measurements were immediately carried out on the irradiated and unirradiated samples. The ESR measurements were performed between 320 and 400?K. ESR spectra were recorded from the samples irradiated for 48 and 72?h. The obtained spectra were observed to be dependent on temperature. Two radical-type centres were detected on the sample. Detected radiation-induced radicals were attributed to R-+?NH and R=?CC2H2. The g-values and hyperfine constants were calculated by means of the experimental spectra. It was also determined from TGA spectrum that both the unirradiated and irradiated samples were decomposed at one step with the rising temperature. Moreover, a theoretical study was presented. Success of the machine learning methods was tested. It was found that bagging techniques, which are widely used in the machine learning literature, could optimise prediction accuracy noticeably. 相似文献
47.
Ali Zoungrana Mehmet Çakmakci İsmail Hakkı Zengin Özlem İnoğlu Harun Elcik 《Chemical Papers》2016,70(9):1185-1195
In this study, the treatability of metal-plating waste water by modified direct contact membrane distillation (DCMD) at different temperature differences (ΔT = 30°C, 40°C, 50°C, and 55°C was investigated. Two different hydrophobic membranes made of poly(tetrafluoroethylene) (PTFE) and poly(vinylidene fluoride) (PVDF) having different pore sizes (0.22 μm and 0.45 μm) were used. The results indicated that conductivity, COD, sulphate, copper, and nickel could be successfully removed by modified DCMD. The rejection efficiencies for conductivity, COD, and sulphate were 99%, 86%, and 99%, respectively. Copper rejection was effective with both membranes while nickel concentration was below the limit of detection in the effluent. It was found that the pollutant rejection efficiency was affected by the raw water characteristics, membrane properties, and influent heating temperatures. In addition to the water quality parameters, the flux was measured to evaluate membrane performance. A high flux was obtained at 65°C (ΔT = 55°C) with 0.45 μm pore size PTFE membrane (24.1 L m?2 h?1) and with PVDF membrane (17.1 L m?2 h?1). The flux was mainly affected by temperature and membrane properties. As a result, modified DCMD and all the membranes used in this study were effective for the treatment of metal-plating waste water. 相似文献
48.
A novel 1‐(cyclobutylmethyl)‐substi‐tuted imidazolidinium/benzimidazolium salts as N‐heterocyclic carbene (NHC) precursors were successfully synthesized and characterized by 1H NMR, 13C NMR, IR, and elemental analysis techniques. These compounds were easily prepared from the reaction of N‐alkyl imidazoline/N‐alkyl benzimidazole with bromomethylcyclobutane in high yields. The in situ formed catalytic system derived from the NHC precursor and Pd(OAc)2 was used in the Heck reaction between aryl halides and styrene with potassium hydroxide in water. The corresponding Heck products were obtained in good yields. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 24:77–83, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21065 相似文献
49.
Synthesis,antioxidant activity and SAR study of novel spiro-isatin-based Schiff bases 总被引:1,自引:0,他引:1
Sonmez Fatih Gunesli Zuhal Kurt Belma Zengin Gazioglu Isil Avci Davut Kucukislamoglu Mustafa 《Molecular diversity》2019,23(4):829-844
Molecular Diversity - A new series of 21 Schiff bases of spiro-isatin was synthesized, and their DPPH, CUPRAC and ABTS cation radical scavenging abilities were investigated for antioxidant... 相似文献
50.
L.D. Gulay D. Kaczorowski A. Szajek 《Journal of Physics and Chemistry of Solids》2008,69(8):1934-1939
The new intermetallic cerium compound CeRhPb was synthesized by arc melting and studied by means of X-ray diffraction and magnetic measurements. The crystal structure determined from the single-crystal X-ray data is of the ZrNiAl type (space group P6¯2m). The compound was found to be a Pauli paramagnet with 4f0 ground state of the Ce atoms. The ab-initio band structure calculations performed without and with spin polarization confirmed the nonmagnetic character of the plumbide studied. 相似文献