Double-beam laser indirect absorption detection in capillary electrophoresis

1993 ◽  
Vol 65 (20) ◽  
pp. 2923-2927 ◽  
Author(s):  
Yongjun. Xue ◽  
Edward S. Yeung
2021 ◽  
Vol 539 ◽  
pp. 148057
Author(s):  
Shuowen Zhang ◽  
Qingyu Yan ◽  
Jian Lin ◽  
Qunli Zhang ◽  
Yongfeng Lu ◽  
...  

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3325 ◽  
Author(s):  
Jovanny Gómez Castaño ◽  
Luc Boussekey ◽  
Jean Verwaerde ◽  
Myriam Moreau ◽  
Yeny Tobón

A new device and methodology for vertically coupling confocal Raman microscopy with optical tweezers for the in situ physico- and photochemical studies of individual microdroplets (Ø ≤ 10 µm) levitated in air is presented. The coupling expands the spectrum of studies performed with individual particles using laser tweezers Raman spectroscopy (LTRS) to photochemical processes and spatially resolved Raman microspectroscopy on airborne aerosols. This is the first study to demonstrate photochemical studies and Raman mapping on optically levitated droplets. By using this configuration, photochemical reactions in aerosols of atmospheric interest can be studied on a laboratory scale under realistic conditions of gas-phase composition and relative humidity. Likewise, the distribution of photoproducts within the drop can also be observed with this setup. The applicability of the coupling system was tested by studying the photochemical behavior of microdroplets (5 µm < Ø < 8 µm) containing an aqueous solution of sodium nitrate levitated in air and exposed to narrowed UV radiation (254 ± 25 nm). Photolysis of the levitated NaNO3 microdroplets presented photochemical kinetic differences in comparison with larger NaNO3 droplets (40 µm < Ø < 80 µm), previously photolyzed using acoustic traps, and heterogeneity in the distribution of the photoproducts within the drop.


2006 ◽  
Vol 301 ◽  
pp. 61-64 ◽  
Author(s):  
Hirofumi Matsuda ◽  
Takashi Iijima

Pr-substituted Bi4Ti3O12 (BPT, Bi4-xPrxTi3O12, x=0.1-0.4) polycrystalline thick films with a-/b-axes orientations and thickness of 2-3 μm were grown on sputter-grown IrO2 layers by chemical solution deposition method for developing lead-free piezoelectric film microdevices. Electric-field-induced strains measurements were performed by double-beam laser displacement meter and longitudinal strain of e=0.25 % under 400 kV/cm and piezoelectric coefficient d33=63 pm/V at 10 Hz were observed in BPT thick film of x=0.1 with a-/b-axes mixed orientations. The value of strain closely related to spontaneous polarization and monotonously decreased with increasing x. Microstructures of 3 μm-thick BPT films were fabricated by photolithography and dry etching processes with several tens micrometers in size.


1996 ◽  
Vol 433 ◽  
Author(s):  
H.D. Chen ◽  
K.K. Li ◽  
C.J. Gaskey ◽  
L.E. Cross

AbstractLanthanum-doped lead zirconate titanate (PLZT) films, with thickness up to 10 μm, are fabricated on platinized silicon substrates through a modified sol-gel technique. Thicknessdependent piezoelectric properties measured with a double-beam laser interferometer show piezoelectric relaxation in field-induced strain as the ac driving field exceeds 10 kV/cm. In addition, the strain levels of PLZT thick films are approximately one third of those of undoped PZT films under the same fabrication and measurement conditions. For 1 μm PZT(55/45) films doped with 0, 2, and 4 mole% La, the P-E hysteresis exhibits decreasing squareness with increasing lanthanum content while the piezoelectric d33 coefficient reduces from 130 to 52 pC/N. Residual (tensile) stress in these films and resulted depoling effect may be responsible for this phenomenon.


1986 ◽  
Vol 40 (4) ◽  
pp. 483-486 ◽  
Author(s):  
K. L. Jansen ◽  
J. M. Harris

While the chemical information provided by electric dichroism spectroscopy can be useful for studying the conformation and electronic structures of molecules in solution, the dichroism signals produced at fields approaching the dielectric strength of organic solvents are extremely small and difficult to detect. A double-beam, laser-based instrument for electric dichroism measurements is described which allows detection of dichroism signals corresponding to changes in absorbance of less than 10−6 with only a 1.2-kV high-voltage source.


2019 ◽  
Vol 18 (1) ◽  
pp. 257-265
Author(s):  
V. V. Chernykh ◽  
V. I. Konenkov ◽  
O. V. Ermakova ◽  
N. B. Orlov ◽  
O. O. Obukhova ◽  
...  

Purpose. To study the content of cytokines and growth factors in the intraocular fluid of patients with developed stage of primary open-angle glaucoma (POAG).Materials and methods. 56 patients with a verified diagnosis developed stage of primary open-angle glaucomawere examined. The control group consisted of 30 patients with a diagnosis of uncomplicated cataract. A concentration of 17 cytokinesand 3 isoforms of the transforming growth factor (TGF) β was determined using a Bio-Plex Pro™ Human Cytokine 17-plex Assay and Bio-Plex Pro™ and TGFβ 3-plex Assay kit by flow-through fluorometry on a Bio-Plex 200, Bio-Rad double beam laser analyzer, USA.Results. Astatistically significant increase was shown in the concentrations of cytokines and growth factors (interleukins (IL) 4, 6, 7, 8, 12, 17, TGFβ 1, 2, 3, macrophage inflammatory protein 1 β) in the intraocular fluid of patients with developed stage of the primary open-angle glaucoma in respect to data obtained from the study of the intraocular fluid of the persons with uncomplicated cataract, as well as a statistically significant decrease in the concentrations IL-2, IL-10, granulocyte-macrophage colony-stimulating factor.Conclusion. In the pathogenesis of primary open-angle glaucoma, the activity of the local chronic inflammatory process is determined. This is confirmed by statistically significant changes in the studied cytokines and growth factors. Increase in the concentrations of the studied representatives of the superfamily of transforming growth factors-beta, which have anti-inflammatory activity, the ability to stimulate proliferation, cell growth, synthesis of extracellular matrix proteins, etc., attests to their importance in the mechanisms of primary open-angle glaucoma development. Increase concentrations of IL-7 in the intraocular fluid of patients with primary open-angle glaucoma allows us to assume participation in the pathogenesis of the primary open-angle glaucoma of this autocrine mediator of activation of the growth of lymphatic structures.


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