For a few years it has been realized that nanocrystalline phases can be formed during crystallization of amorphous alloys annealed isothermally below the crystallization temperature of usual heating experiments. Data ...For a few years it has been realized that nanocrystalline phases can be formed during crystallization of amorphous alloys annealed isothermally below the crystallization temperature of usual heating experiments. Data of this transformation monitored by the measurement of magnetic susceptibility are presented. A method using a magnetic balance with electronic stabilisation and combined computer facilities is applied. Constant heating and cooling rates as well as isothermal heat treatments are used. Magnetic measurements are able to detect the onset of the transformation of amorphous NI-P alloys much earlier than was possible with differential scanning calorimetry. The transformation kinetics can be analyzed by means of the Avrami plot based on the Johnson-Mehl-Avrami equation. The kinetics of solid state reactions in the nanostructured material can be investigated similarly. Formation of a Ni-phase in a nanostructured Hf-Ni alloy could be detected in a very early stage, where calorimetric methods are not sensitive. Segregation phenomena could be detected from the experiments even after long time. The sensitivity of the applied method is not dependent on the heating rate as the sensitivity of scanning calorimetry is.展开更多
The development of smart drug delivery systems(SDDSs)based on engineered nanomaterials is important for clinical applications.Nevertheless,controllable administration of chemotherapeutic drugs for deep tumors and the ...The development of smart drug delivery systems(SDDSs)based on engineered nanomaterials is important for clinical applications.Nevertheless,controllable administration of chemotherapeutic drugs for deep tumors and the avoidance of side effects caused by off-targeting during delivery remain a great challenge.Herein,a stimulus-responsive system of mesoporous nanospheres(composed of Cu@Fe_(2)C@mSiO_(2))with good magnetothermal effect is introduced into the tumor microenvironment.This system plays an important role in image-guided controllable targeted drug delivery that is independent of tumor depth.Aggregation-induced emission luminogen-based fluorescence imaging and magnetic resonance imaging were utilized since these techniques visualize the delivery process in real time.In addition,the degraded nanocarriers showed high catalytic activity for Fenton and Fenton-like reactions,upregulating the level of hydroxyl radicals(•OH)in cancer cells to realize chemodynamic therapy.The induced•OH led to the overexpression of pho-STAT3,activating the STAT3 signaling pathway,eventually inducing cancer cell apoptosis.Through metabolic monitoring,this SDDS is removed from the body after its degradation in vivo.The synergistically enhanced therapeutic effect was obtained in the chemo-chemodynamic therapy of 4T1 tumor-bearing mice,offering a platform for efficient cancer therapy with a personalized theranostic strategy.展开更多
The isothermal section of the Ho-Fe-In system at 773 K has been constructed by X-ray powder diffraction.One known structure ternary compound Er_(12)Fe_(2) In_(3)-type Ho_(12)Fe_(2) In_(3) has been confirmed.At the sam...The isothermal section of the Ho-Fe-In system at 773 K has been constructed by X-ray powder diffraction.One known structure ternary compound Er_(12)Fe_(2) In_(3)-type Ho_(12)Fe_(2) In_(3) has been confirmed.At the same time,solid solutions are not detected in Ho-Fe-In system at 773 K.The magnetic transition and magnetocaloric effect of Ho_(12)Fe_(2.08)In_(2.92) alloy with Er_(12)Fe_(2) In_(3)-type structure were investigated by magnetic susceptibility and isothermal magnetization measurements.One normal antiferromagnetic-paramagnetic transition and another abnormal one are discovered at 18 and 76 K in ground state,respectively.Owing to a first-order field-induced metamagnetic transition(antiferromagnetic-ferromagnetic) at/below the Neel temperature of 18 K),the negative entropy changes are observed at corresponding temperature.There is only a second-order ferromagnetic-paramagnetic transition near Curie temperature(TC),the maximum entropy change(Δ_(Smax)) values are-6.14 J·kg^(-1)·K^(-1) at 3 K and 7.88 J·kg^(-1)·K^(-1) at 28 K in a field range of 0-7 T.The reversible relative cooling power corresponding to negative entropy change can reach about 600 J·kg^(-1) in an wide operating temperature region Δ_(Tcycl)=74 K from 16 to90 K,which suggests that Ho_(12)Fe_(2.08)In_(2.92) could be a potential material for magnetic refrigeration in the corresponding temperature range.展开更多
In response to global energy scarcity,frontiers in multifunctional composite phase change materials(PCMs)with photo-/electro-/magnetothermal triggers show great potential in multiple energy utilization.However,most av...In response to global energy scarcity,frontiers in multifunctional composite phase change materials(PCMs)with photo-/electro-/magnetothermal triggers show great potential in multiple energy utilization.However,most available composite PCM candidates are inadequate for multiple energy storage applications simultaneously.Herein,a green synthetic route is proposed to develop bimetallic zeolitic imidazolate framework(ZIF)-derived 1D–2D bridged array carbon-based composite PCMs for simultaneous photo-/electro-/magnetothermal energy storage applications.As graphitization-induced catalyst,Co nanoparticles greatly boost the formation of ZIF-derived 1D–2D bridged array carbon framework with high graphitization and low interface electrical/thermal resistance.Benefiting from the broadband intense photon capture,fast photon/electron/phonon transport,and surface plasma resonance effect of Co nanoparticles,the resulting composite PCMs integrate advanced photo-,electro-,and magnetothermal storage functions.Furthermore,composite PCMs also exhibit long-lasting shape stability,structural stability,thermal storage stability,and photo-/electro-/magnetothermal storage stability after undergoing multiple heating–cooling cycles.This study is promising to accelerate the major breakthroughs of advanced multifunctional carbon-based composite PCMs toward multiple energy utilization.展开更多
The aggregation of amyloid-β peptide （Aβ） is implicated in the pathology of Alzheimer＇s disease （AD）, and Aβ oligomers are considered the most toxic species. Therefore, the detection and clearance of Aβ oligo...The aggregation of amyloid-β peptide （Aβ） is implicated in the pathology of Alzheimer＇s disease （AD）, and Aβ oligomers are considered the most toxic species. Therefore, the detection and clearance of Aβ oligomers are crucial for the theranostic strategies for AD. However, effective methods for the detection of Aβ oligomers are rare, and only few of the oligomer-specific sensors have therapeutic functions as well. Recent studies have demonstrated that the toxicity of Aβ oligomers is related to the number of exposed hydrophobic residues. In this study, an oligomer-specific fluorescent probe, which was based on the hydrophobic regions that are exposed on Aβ oligomer surfaces was designed and synthesized. For improving the ability to recognize Aβ oligomers, the in situ treatment of AD symptoms and the ability to penetrate the blood-brain barrier, the probe and KLVFF peptide （an Aβ-target peptide） were modified on the surfaces of magnetic nanoparticles （MNP@NFP-pep）. This complex could detect Aβ oligomers specifically, and achieve the wireless deep magnetothermally mediated disaggregation of Aβ aggregates with an alternating magnetic field. This work provides new insights into the development of a ＂sense and treat＂ system for AD therapy.展开更多
文摘For a few years it has been realized that nanocrystalline phases can be formed during crystallization of amorphous alloys annealed isothermally below the crystallization temperature of usual heating experiments. Data of this transformation monitored by the measurement of magnetic susceptibility are presented. A method using a magnetic balance with electronic stabilisation and combined computer facilities is applied. Constant heating and cooling rates as well as isothermal heat treatments are used. Magnetic measurements are able to detect the onset of the transformation of amorphous NI-P alloys much earlier than was possible with differential scanning calorimetry. The transformation kinetics can be analyzed by means of the Avrami plot based on the Johnson-Mehl-Avrami equation. The kinetics of solid state reactions in the nanostructured material can be investigated similarly. Formation of a Ni-phase in a nanostructured Hf-Ni alloy could be detected in a very early stage, where calorimetric methods are not sensitive. Segregation phenomena could be detected from the experiments even after long time. The sensitivity of the applied method is not dependent on the heating rate as the sensitivity of scanning calorimetry is.
基金supported by the National Natural Science Foundation of China(grant nos.52027801,51631001,and 52001008)the National Key R&D Program of China(grant no.2017YFA0206301)+1 种基金the Natural Science Foundation of Beijing Municipality(grant no.2191001)the China-German Collaboration Project(grant no.M-0199).
文摘The development of smart drug delivery systems(SDDSs)based on engineered nanomaterials is important for clinical applications.Nevertheless,controllable administration of chemotherapeutic drugs for deep tumors and the avoidance of side effects caused by off-targeting during delivery remain a great challenge.Herein,a stimulus-responsive system of mesoporous nanospheres(composed of Cu@Fe_(2)C@mSiO_(2))with good magnetothermal effect is introduced into the tumor microenvironment.This system plays an important role in image-guided controllable targeted drug delivery that is independent of tumor depth.Aggregation-induced emission luminogen-based fluorescence imaging and magnetic resonance imaging were utilized since these techniques visualize the delivery process in real time.In addition,the degraded nanocarriers showed high catalytic activity for Fenton and Fenton-like reactions,upregulating the level of hydroxyl radicals(•OH)in cancer cells to realize chemodynamic therapy.The induced•OH led to the overexpression of pho-STAT3,activating the STAT3 signaling pathway,eventually inducing cancer cell apoptosis.Through metabolic monitoring,this SDDS is removed from the body after its degradation in vivo.The synergistically enhanced therapeutic effect was obtained in the chemo-chemodynamic therapy of 4T1 tumor-bearing mice,offering a platform for efficient cancer therapy with a personalized theranostic strategy.
基金financially supported by the Department of Science and Technology of Sichuan Province in China(No.2017JY0181)。
文摘The isothermal section of the Ho-Fe-In system at 773 K has been constructed by X-ray powder diffraction.One known structure ternary compound Er_(12)Fe_(2) In_(3)-type Ho_(12)Fe_(2) In_(3) has been confirmed.At the same time,solid solutions are not detected in Ho-Fe-In system at 773 K.The magnetic transition and magnetocaloric effect of Ho_(12)Fe_(2.08)In_(2.92) alloy with Er_(12)Fe_(2) In_(3)-type structure were investigated by magnetic susceptibility and isothermal magnetization measurements.One normal antiferromagnetic-paramagnetic transition and another abnormal one are discovered at 18 and 76 K in ground state,respectively.Owing to a first-order field-induced metamagnetic transition(antiferromagnetic-ferromagnetic) at/below the Neel temperature of 18 K),the negative entropy changes are observed at corresponding temperature.There is only a second-order ferromagnetic-paramagnetic transition near Curie temperature(TC),the maximum entropy change(Δ_(Smax)) values are-6.14 J·kg^(-1)·K^(-1) at 3 K and 7.88 J·kg^(-1)·K^(-1) at 28 K in a field range of 0-7 T.The reversible relative cooling power corresponding to negative entropy change can reach about 600 J·kg^(-1) in an wide operating temperature region Δ_(Tcycl)=74 K from 16 to90 K,which suggests that Ho_(12)Fe_(2.08)In_(2.92) could be a potential material for magnetic refrigeration in the corresponding temperature range.
基金National Natural Science Foundation of China,Grant/Award Number:51902025。
文摘In response to global energy scarcity,frontiers in multifunctional composite phase change materials(PCMs)with photo-/electro-/magnetothermal triggers show great potential in multiple energy utilization.However,most available composite PCM candidates are inadequate for multiple energy storage applications simultaneously.Herein,a green synthetic route is proposed to develop bimetallic zeolitic imidazolate framework(ZIF)-derived 1D–2D bridged array carbon-based composite PCMs for simultaneous photo-/electro-/magnetothermal energy storage applications.As graphitization-induced catalyst,Co nanoparticles greatly boost the formation of ZIF-derived 1D–2D bridged array carbon framework with high graphitization and low interface electrical/thermal resistance.Benefiting from the broadband intense photon capture,fast photon/electron/phonon transport,and surface plasma resonance effect of Co nanoparticles,the resulting composite PCMs integrate advanced photo-,electro-,and magnetothermal storage functions.Furthermore,composite PCMs also exhibit long-lasting shape stability,structural stability,thermal storage stability,and photo-/electro-/magnetothermal storage stability after undergoing multiple heating–cooling cycles.This study is promising to accelerate the major breakthroughs of advanced multifunctional carbon-based composite PCMs toward multiple energy utilization.
基金Financial support was provided by the National Basic Research Program of China （973 Program） （No. 2012CB720602）, the Project of Science and Technology Development Plan for Jilin Province （No. 20150520004JH） and the National Natural Science Foundation of China （NSFC） （Nos. 21210002, 21431007, 21402183 and 21533008）.
文摘The aggregation of amyloid-β peptide （Aβ） is implicated in the pathology of Alzheimer＇s disease （AD）, and Aβ oligomers are considered the most toxic species. Therefore, the detection and clearance of Aβ oligomers are crucial for the theranostic strategies for AD. However, effective methods for the detection of Aβ oligomers are rare, and only few of the oligomer-specific sensors have therapeutic functions as well. Recent studies have demonstrated that the toxicity of Aβ oligomers is related to the number of exposed hydrophobic residues. In this study, an oligomer-specific fluorescent probe, which was based on the hydrophobic regions that are exposed on Aβ oligomer surfaces was designed and synthesized. For improving the ability to recognize Aβ oligomers, the in situ treatment of AD symptoms and the ability to penetrate the blood-brain barrier, the probe and KLVFF peptide （an Aβ-target peptide） were modified on the surfaces of magnetic nanoparticles （MNP@NFP-pep）. This complex could detect Aβ oligomers specifically, and achieve the wireless deep magnetothermally mediated disaggregation of Aβ aggregates with an alternating magnetic field. This work provides new insights into the development of a ＂sense and treat＂ system for AD therapy.
