We investigated the effect of processing conditions on the structure and physical properties of the polycrystalline samples of Ca0.8Fe2Se2 prepared via solid state reaction. X-ray diffraction showed that the main phas...We investigated the effect of processing conditions on the structure and physical properties of the polycrystalline samples of Ca0.8Fe2Se2 prepared via solid state reaction. X-ray diffraction showed that the main phase became FeSe when the sintering temperature increased above 350 ℃. The temperature dependence of magnetization （M-T curves） recorded in zero-field-cooled mode by SQUID magnetometer showed some bumps at around 120 K to 140 K. These bumps moved to lower temperatures when the processing temperature increased above 550 ℃. On the other hand, pure FeSe materials produced at 900 ℃ for 24 h showed a sharp superconducting transition Tconset = 8.16 K and the critical current density of 6,252 A/cm2 at 5 K, self-field. SEM results indicated an enhanced grain connectivity.展开更多
We report on the magnetic,magnetocaloric,thermal,and electrical transport properties of Tb_(4)Coln alloy,which crystallizes in two phases,Tb_6Co_(2.1)In_(0.8)(space group Immm)and Tb_(2)In_(0.9)Co_(0.1)(space group P6...We report on the magnetic,magnetocaloric,thermal,and electrical transport properties of Tb_(4)Coln alloy,which crystallizes in two phases,Tb_6Co_(2.1)In_(0.8)(space group Immm)and Tb_(2)In_(0.9)Co_(0.1)(space group P6_(3)/mmc),respectively.The alloy reveals three successive magnetic transitions around T_(1)(163 K),T_(2)(50 K),and T_(3)(29 K),respectively,associated with paramagnetic to ferromagnetic transition and two sequential antiferromagnetic transitions.The low-temperature transition T_(3) follows the first-order magnetic behavior and exhibits the field-induced magnetic transition.Meanwhile,T_(2) and T_(1) are found to be second-order in nature which opens a possibility for hysteresis-free magnetocaloric application.The magnetocaloric properties are determined using different magnetocaloric figures of merits such as-ΔS_(M),ΔT_(ad).RCP,and TEC(10).Additionally,the universal curve behavior in the isothermal entropy change unveils the variation in critical exponents around T_(1) and T_(2) due to the magnetic inhomogeneity in the alloy.Besides,the electrical transport properties of the metallic alloy denote the maximum magnetoresistance of-10%around T_(1).展开更多
Several attempts have appeared recently to control optical trapping systems via touch tablets and cameras instead of a mouse and joystick. Our approach is based on a modern low-cost hardware combined with fingertips a...Several attempts have appeared recently to control optical trapping systems via touch tablets and cameras instead of a mouse and joystick. Our approach is based on a modern low-cost hardware combined with fingertips and speech recognition software. Positions of operator's hands or fingertips control the positions of trapping beams in holographic optical tweezers that provide optical manipulation with microobjects. We tested and adapted two systems for hands position detection and gestures recognition – Creative Interactive Gesture Camera and Leap Motion. We further enhanced the system of Holographic Raman tweezers (HRT) by voice commands controlling the micropositioning stage and acquisition of Raman spectra. Interface communicates with HRT either directly by which requires adaptation of HRT firmware, or indirectly by simulating mouse and keyboard messages. Its utilization in real experiments speeded up the operator’s communication with the system cca. Two times in comparison with the traditional control by the mouse and the keyboard.展开更多
The formation of amyloid fibrils from soluble proteins is a common form of self-assembly phenomenon that has fundamental connections with biological functions and human diseases.Lysozyme was converted from its soluble...The formation of amyloid fibrils from soluble proteins is a common form of self-assembly phenomenon that has fundamental connections with biological functions and human diseases.Lysozyme was converted from its soluble native state into highly organized amyloid fibrils.Ultrasonic treatment was used to break amyloid fibrils to fibrillar fragments–seeds.Atomic force microscopy and fluorescence microscopy was employed to characterize the morphology of the amyloid assemblies and neural cells–amyloid complexes.Our results demonstrate that prefibrillar intermediated and their mixture with proteins exhibit toxicity,although native proteins and fibrils appear to have no effect on number of cells.Our findings confirm that innocuous hen lysozyme can be engineered to produce both cytotoxic fibrillar fragments and non-toxic mature amyloid fibrils.Our work further strengthens the claim that amyloid conformation,and not the identity of the protein,is key to cellular toxicity and the underlying specific cell death mechanism.展开更多
文摘We investigated the effect of processing conditions on the structure and physical properties of the polycrystalline samples of Ca0.8Fe2Se2 prepared via solid state reaction. X-ray diffraction showed that the main phase became FeSe when the sintering temperature increased above 350 ℃. The temperature dependence of magnetization （M-T curves） recorded in zero-field-cooled mode by SQUID magnetometer showed some bumps at around 120 K to 140 K. These bumps moved to lower temperatures when the processing temperature increased above 550 ℃. On the other hand, pure FeSe materials produced at 900 ℃ for 24 h showed a sharp superconducting transition Tconset = 8.16 K and the critical current density of 6,252 A/cm2 at 5 K, self-field. SEM results indicated an enhanced grain connectivity.
基金Project supported by the University Science Park TECHNICOM for Innovation Applications supported by Knowledge Technology (313011D232)supported by the Research&Development Operational Programme funded by the ERDFVEGA1/0705/20,1/0404/21。
文摘We report on the magnetic,magnetocaloric,thermal,and electrical transport properties of Tb_(4)Coln alloy,which crystallizes in two phases,Tb_6Co_(2.1)In_(0.8)(space group Immm)and Tb_(2)In_(0.9)Co_(0.1)(space group P6_(3)/mmc),respectively.The alloy reveals three successive magnetic transitions around T_(1)(163 K),T_(2)(50 K),and T_(3)(29 K),respectively,associated with paramagnetic to ferromagnetic transition and two sequential antiferromagnetic transitions.The low-temperature transition T_(3) follows the first-order magnetic behavior and exhibits the field-induced magnetic transition.Meanwhile,T_(2) and T_(1) are found to be second-order in nature which opens a possibility for hysteresis-free magnetocaloric application.The magnetocaloric properties are determined using different magnetocaloric figures of merits such as-ΔS_(M),ΔT_(ad).RCP,and TEC(10).Additionally,the universal curve behavior in the isothermal entropy change unveils the variation in critical exponents around T_(1) and T_(2) due to the magnetic inhomogeneity in the alloy.Besides,the electrical transport properties of the metallic alloy denote the maximum magnetoresistance of-10%around T_(1).
文摘Several attempts have appeared recently to control optical trapping systems via touch tablets and cameras instead of a mouse and joystick. Our approach is based on a modern low-cost hardware combined with fingertips and speech recognition software. Positions of operator's hands or fingertips control the positions of trapping beams in holographic optical tweezers that provide optical manipulation with microobjects. We tested and adapted two systems for hands position detection and gestures recognition – Creative Interactive Gesture Camera and Leap Motion. We further enhanced the system of Holographic Raman tweezers (HRT) by voice commands controlling the micropositioning stage and acquisition of Raman spectra. Interface communicates with HRT either directly by which requires adaptation of HRT firmware, or indirectly by simulating mouse and keyboard messages. Its utilization in real experiments speeded up the operator’s communication with the system cca. Two times in comparison with the traditional control by the mouse and the keyboard.
基金supported by Slovak grand agency VEGA 2/0145/17,MVTS COST 083/14 action BM1405,SAS-MOST JRP 2015/5 and CNR-SAS bilateral projects CUP B52F15000340005 and CUP B52I12000320005,Italian flagship NANOMAX,N-CHEM。
文摘The formation of amyloid fibrils from soluble proteins is a common form of self-assembly phenomenon that has fundamental connections with biological functions and human diseases.Lysozyme was converted from its soluble native state into highly organized amyloid fibrils.Ultrasonic treatment was used to break amyloid fibrils to fibrillar fragments–seeds.Atomic force microscopy and fluorescence microscopy was employed to characterize the morphology of the amyloid assemblies and neural cells–amyloid complexes.Our results demonstrate that prefibrillar intermediated and their mixture with proteins exhibit toxicity,although native proteins and fibrils appear to have no effect on number of cells.Our findings confirm that innocuous hen lysozyme can be engineered to produce both cytotoxic fibrillar fragments and non-toxic mature amyloid fibrils.Our work further strengthens the claim that amyloid conformation,and not the identity of the protein,is key to cellular toxicity and the underlying specific cell death mechanism.
