Current study presents an advanced method for improving the visualization of subsurface blood vessels using laser speckle contrast imaging (LSCI), enhanced through principal component analysis (PCA) filtering. By comb...Current study presents an advanced method for improving the visualization of subsurface blood vessels using laser speckle contrast imaging (LSCI), enhanced through principal component analysis (PCA) filtering. By combining LSCI and laser speckle entropy imaging with PCA filtering, the method effectively separates static and dynamic components of the speckle signal, significantly improving the accuracy of blood flow assessments, even in the presence of static scattering layers located above and below the vessel. Experiments conducted on optical phantoms, with the vessel depths ranging from 0.6 to 2 mm, and in vivo studies on a laboratory mouse ear demonstrate substantial improvements in image contrast and resolution. The method’s sensitivity to blood flow velocity within the physiologic range (0.98-19.66 mm/s) is significantly enhanced, while its sensitivity to vessel depth is minimized. These results highlight the method’s ability to assess blood flow velocity independently of vessel depth, overcoming a major limitation of conventional LSCI techniques. The proposed approach holds great potential for non-invasive biomedical imaging, offering improved diagnostic accuracy and contrast in vascular imaging. These findings may be particularly valuable for advancing the use of LSCI in clinical diagnostics and biomedical research, where high precision in blood flow monitoring is essential.展开更多
The efficiency of devices for bioelectronic applications,including cell and tissue stimulation,is heavily dependent on the scale and the performance level.With miniaturization of stimulation electrodes,achieving a suf...The efficiency of devices for bioelectronic applications,including cell and tissue stimulation,is heavily dependent on the scale and the performance level.With miniaturization of stimulation electrodes,achieving a sufficiently high current pulse to elicit action potentials becomes an issue.Herein we report on our approach of vertically stacking organic p-n junctions to create highlyefficient multilayered organic semiconductor(MOS)photostimulation device.A tandem arrangement substantially increases the photovoltage and charge density without sacrificing lateral area,while not exceeding 200-500 nm of thickness.These devices generate 4 times higher voltages and at least double the charge densities over single p-n junction devices,which allow using lower light intensities for stimulation.MOS devices show an outstanding stability in the electrolyte that is extremely important for forthcoming in vivo experiments.Finally,we have validated MOS devices performance by photostimulating fibroblasts and neuroblasts,and found that using tandem devices leads to more effective action potential generation.As a result,we obtained up to 4 times enhanced effect in cell growth density using 3 p-n layered devices.These results corroborate the conclusion that MOS technology not only can achieve parity with state-of-the-art silicon devices,but also can exceed them in miniaturization and performance for biomedical applications.展开更多
For the first time, a highly crystalline porous shish-kebab structure with a high degree of crystallinity was obtained by using a combination of two methods for the formation of porous polymeric materials. A treatment...For the first time, a highly crystalline porous shish-kebab structure with a high degree of crystallinity was obtained by using a combination of two methods for the formation of porous polymeric materials. A treatment procedure using supercritical carbon dioxide(sc CO_(2))was carried out for oriented ultrahigh molecular weight polyethylene(UHMWPE) films, which provided special conditions for the crystallization of dissolved UHMWPE macromolecules on the surface of oriented UHMWPE crystals. The prepared porous materials were investigated by scanning electron microscopy(SEM) and differential scanning calorimetry(DSC). The particularity of the obtained porous shish-kebab is the absence of the amorphous phase between lamellar crystals(kebabs). The obtained pores had an oval shape, and they were oriented in the orientation direction of the UHMWPE macromolecules. The pore size ranged from 0.05 μm to 4 μm. Controlling the conditions for the crystallization of the UHMWPE macromolecules using supercritical CO_(2) gives the possibility to control the size of both lamellar disks and pores formed.展开更多
In this paper,we report on the crystal structure and magnetic properties of the nano structured Baordered phases of rare-earth manganites obtained from the optimally doped solid solutions Ln0.70Ba0.30MnO3(Ln=Pr,Nd).Th...In this paper,we report on the crystal structure and magnetic properties of the nano structured Baordered phases of rare-earth manganites obtained from the optimally doped solid solutions Ln0.70Ba0.30MnO3(Ln=Pr,Nd).The materials were studied by X-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy and SQUID-magnetometry techniques.It is found that states with different degrees of cation ordering in the A-sublattice of the ABO3 perovskite can be obtained by employing special conditions of chemical treatment.In particular,reduction of the parent compounds results in the formation of a nanocomposite containing ferrimagnetic anion-deficient ordered phase LnBaMn2O5.Oxidation of the composite does not change an average size of the nanocrystallites,but drastically alters their phase composition to stabilize ferromagnetic stoichiometric ordered phase LnBaMn2O6 and ferromagnetic superstoichiometric disordered phase Ln0.90Ba0.10MnO3+δ.It is shown that the magnetic properties of the materials are determined by the joint action of chemical(cation ordering)and external(surface tension)pressures.展开更多
文摘Current study presents an advanced method for improving the visualization of subsurface blood vessels using laser speckle contrast imaging (LSCI), enhanced through principal component analysis (PCA) filtering. By combining LSCI and laser speckle entropy imaging with PCA filtering, the method effectively separates static and dynamic components of the speckle signal, significantly improving the accuracy of blood flow assessments, even in the presence of static scattering layers located above and below the vessel. Experiments conducted on optical phantoms, with the vessel depths ranging from 0.6 to 2 mm, and in vivo studies on a laboratory mouse ear demonstrate substantial improvements in image contrast and resolution. The method’s sensitivity to blood flow velocity within the physiologic range (0.98-19.66 mm/s) is significantly enhanced, while its sensitivity to vessel depth is minimized. These results highlight the method’s ability to assess blood flow velocity independently of vessel depth, overcoming a major limitation of conventional LSCI techniques. The proposed approach holds great potential for non-invasive biomedical imaging, offering improved diagnostic accuracy and contrast in vascular imaging. These findings may be particularly valuable for advancing the use of LSCI in clinical diagnostics and biomedical research, where high precision in blood flow monitoring is essential.
基金funded by the Ministry of Science and Higher Education of the Russian Federation(No.075-15-2021-596).
文摘The efficiency of devices for bioelectronic applications,including cell and tissue stimulation,is heavily dependent on the scale and the performance level.With miniaturization of stimulation electrodes,achieving a sufficiently high current pulse to elicit action potentials becomes an issue.Herein we report on our approach of vertically stacking organic p-n junctions to create highlyefficient multilayered organic semiconductor(MOS)photostimulation device.A tandem arrangement substantially increases the photovoltage and charge density without sacrificing lateral area,while not exceeding 200-500 nm of thickness.These devices generate 4 times higher voltages and at least double the charge densities over single p-n junction devices,which allow using lower light intensities for stimulation.MOS devices show an outstanding stability in the electrolyte that is extremely important for forthcoming in vivo experiments.Finally,we have validated MOS devices performance by photostimulating fibroblasts and neuroblasts,and found that using tandem devices leads to more effective action potential generation.As a result,we obtained up to 4 times enhanced effect in cell growth density using 3 p-n layered devices.These results corroborate the conclusion that MOS technology not only can achieve parity with state-of-the-art silicon devices,but also can exceed them in miniaturization and performance for biomedical applications.
基金financially supported by the Academic leadership program Priority 2030 proposed by Federal State Autonomous Educational Institution of Higher Education I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University)The preparation and modification of UHMWPE samples were financially supported by the Russian Science Foundation (No.18-13-00145)SEM investigation was supported by the State Assignment (No.0090-2019-0002, IPAC RAS)。
文摘For the first time, a highly crystalline porous shish-kebab structure with a high degree of crystallinity was obtained by using a combination of two methods for the formation of porous polymeric materials. A treatment procedure using supercritical carbon dioxide(sc CO_(2))was carried out for oriented ultrahigh molecular weight polyethylene(UHMWPE) films, which provided special conditions for the crystallization of dissolved UHMWPE macromolecules on the surface of oriented UHMWPE crystals. The prepared porous materials were investigated by scanning electron microscopy(SEM) and differential scanning calorimetry(DSC). The particularity of the obtained porous shish-kebab is the absence of the amorphous phase between lamellar crystals(kebabs). The obtained pores had an oval shape, and they were oriented in the orientation direction of the UHMWPE macromolecules. The pore size ranged from 0.05 μm to 4 μm. Controlling the conditions for the crystallization of the UHMWPE macromolecules using supercritical CO_(2) gives the possibility to control the size of both lamellar disks and pores formed.
基金Project supported by the European Union’s Horizon 2020Research and Innovation Programme under the Marie Sklodowska-Curie grant agreement(778070)
文摘In this paper,we report on the crystal structure and magnetic properties of the nano structured Baordered phases of rare-earth manganites obtained from the optimally doped solid solutions Ln0.70Ba0.30MnO3(Ln=Pr,Nd).The materials were studied by X-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy and SQUID-magnetometry techniques.It is found that states with different degrees of cation ordering in the A-sublattice of the ABO3 perovskite can be obtained by employing special conditions of chemical treatment.In particular,reduction of the parent compounds results in the formation of a nanocomposite containing ferrimagnetic anion-deficient ordered phase LnBaMn2O5.Oxidation of the composite does not change an average size of the nanocrystallites,but drastically alters their phase composition to stabilize ferromagnetic stoichiometric ordered phase LnBaMn2O6 and ferromagnetic superstoichiometric disordered phase Ln0.90Ba0.10MnO3+δ.It is shown that the magnetic properties of the materials are determined by the joint action of chemical(cation ordering)and external(surface tension)pressures.
