Based on the study of oxygen isotope and mi-croparticle in the Guliya ice core, atmospheric dust and en-vironmental changes in the northwest Tibetan Plateau since the last interglacial were revealed. The microparticle...Based on the study of oxygen isotope and mi-croparticle in the Guliya ice core, atmospheric dust and en-vironmental changes in the northwest Tibetan Plateau since the last interglacial were revealed. The microparticle record indicates that low dust load on the Plateau in the interglacial. Particle concentration increased rapidly when the climate turned into the last glacial and reached the maximum during the MIS 4. In the Last Glacial Maximum, however, the en-hancement of microparticle concentration was slight, differ-ing to those in the Antarctic and Greenland. On the orbital timescale, both the temperature on the Tibetan Plateau and summer solar insolation in the Northern Hemisphere had their impact on the microparticle record, but the difference in phase and amplitude also existed. Though having the same dust source, microparticle records in the ice cores on the Tibetan Plateau and the Greenland seem to have different significance.展开更多
Microvesicles （MVs, also known as microparticles） are small vesicles that originate from plasma membrane of almost all eukaryotic cells during apoptosis or activation. MVs can serve as extracellular vehicles to tran...Microvesicles （MVs, also known as microparticles） are small vesicles that originate from plasma membrane of almost all eukaryotic cells during apoptosis or activation. MVs can serve as extracellular vehicles to transport bioactive molecules from their parental cells to recipient target cells, thereby serving as novel mediators for intercellular communication. Importantly, more and more evidence indicates that MVs could play important roles in early pathogenesis and subsequent progression of cardiovascular and metabolic diseases. Elevated plasma concentrations of MVs, originating from red blood cells, leukocytes, platelets, or other organs and tissues, have been reported in various cardiometabolic diseases. Circulating MVs could serve as potential biomarkers for disease diagnosis or therapeutic monitoring. In this review, we summarized recently- published studies in the field and discussed the role of MVs in the pathogenesis of cardiometabolic diseases. The emerging values of MVs that serve as biomarker for non-invasive diagnosis and prog- nosis, as well as their roles as novel therapeutic targets in cardiometabolic diseases, were also described.展开更多
Background: Microparticles (MPs) are small extracellular plasma membrane particles shed by activated and apoptotic cells, which are involved in the development of atherosclerosis. Our previous study found that microRN...Background: Microparticles (MPs) are small extracellular plasma membrane particles shed by activated and apoptotic cells, which are involved in the development of atherosclerosis. Our previous study found that microRNA (miR)-19b encapsulated within endothelial MPs (EMPs) may contribute to the upregulation of circulating miR-19b in unstable angina patients. Hypoxia is involved in atherosclerosis as a critical pathological stimulus. However, it still remains unclear whether the increase of miR-19b levels in EMPs is related to hypoxia and if the effect of miR-19b - wrapped within EMPs - stimulates hypoxia on vascular endothelial cells. This study aimed to explore the changes of miR-19b in EMPs induced by hypoxia as well as their effects on endothelial cells.Methods: Human umbilical vein endothelial cells (HUVECs) were culturedin vitro and arranged to harvest EMPs in two parts: the first part consisted of EMPcontrol and EMPhypoxia and the second part included EMPvehicle, EMPNC mimic, and EMPmiR-19b mimic. Cell migration was detected by scratch migration and transwell chamber migration. Angiogenesis was assessed by tube formation assays. Furthermore, we predicted the target gene of miR-19b by bioinformatics analysis, and luciferase assay was used to verify the targeted gene of miR-19b. Data were analyzed by one-way analysis of variance. Student’st-test was used when two groups were compared.Results: Compared with EMPcontrol- and EMPhypoxia-inhibited migration of cells by scratch migration assay (80.77 ± 1.10 vs. 28.37 ± 1.40,P < 0. 001) and transwell chamber migration assay (83.00 ± 3.46 vs. 235.00 ± 16.52,P < 0.01), the number of tube formations was markedly reduced by 70% in the EMPhypoxia group (P < 0.001)in vitro analysis of HUVECs. Meanwhile, a strong inhibition of migration and tube formation of HUVECs in the presence of miR-19b-enriched EMPmiR-19b mimic was observed. This effect might be due to the delivery of miR-19b in EMPs. Transforming growth factor-β2 (TGFβ2) was predicted to be one of the target g展开更多
Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scannin...Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scanning electronic microscopy, X-ray diffraction and infrared radiation were used to examine particle size, crystallinity and chemical structure. The results show that B-HMX microparticle in different average size (2-9.5um) and with narrow size distribution were obtained by controlling the expansibility, expansion speed, initial concentration and temperature during recrystallization of HMX. The formation of nuclei may be a main cause of consumption of solute when the solution is expanded rapidly enough and the equilibrium concentration is lower, in which almost monodisperse microparticle can be obtained.展开更多
Nanoporous silicon is a promising anode material for high energy density batteries due to its high cycling stability and high tap density compared to other nanostructured anode materials.However,the high cost of synth...Nanoporous silicon is a promising anode material for high energy density batteries due to its high cycling stability and high tap density compared to other nanostructured anode materials.However,the high cost of synthesis and low yield of nanoporous silicon limit its practical application.Here,we develop a scalable,low-cost top-down process of controlled oxidation of Mg2Si in the air,followed by HCl removal of MgO to generate nanoporous silicon without the use of HF.By controlling the synthesis conditions,the oxygen content,grain size and yield of the porous silicon are simultaneously optimized from commercial standpoints.In situ environmental transmission electron microscopy reveals the reaction mechanism;the Mg2Si microparticle reacts with O2 to form MgO and Si,while preventing SiO2 formation.Owing to the low oxygen content and microscale secondary structure,the nanoporous silicon delivers a higher initial reversible capacity and initial Coulombic efficiency compared to commercial Si nanoparticles(3,033 mAh/g vs.2,418 mAh/g,84.3%vs.73.1%).Synthesis is highly scalable,and a yield of 90.4%is achieved for the porous Si nanostructure with the capability to make an excess of 10 g per batch.Our synthetic nanoporous silicon is promising for practical applications in next generation lithium-ion batteries.展开更多
Non-small cell lung cancer(NSCLC) accounts for about 85% of all lung cancers. Traditional chemotherapy for this disease leads to serious side effects. Here we prepared an inhalable oridonin-loaded poly(lactic-co-glyco...Non-small cell lung cancer(NSCLC) accounts for about 85% of all lung cancers. Traditional chemotherapy for this disease leads to serious side effects. Here we prepared an inhalable oridonin-loaded poly(lactic-co-glycolic)acid(PLGA) large porous microparticle(LPMP) for in situ treatment of NSCLC with the emulsion/solvent evaporation/freeze-drying method. The LPMPs were smooth spheres with many internal pores. Despite a geometric diameter of 10 mm, the aerodynamic diameter of the spheres was only 2.72 mm, leading to highly efficient lung deposition. In vitro studies showed that most of oridonin was released after 1 h, whereas the alveolar macrophage uptake of LPMPs occurred after 8 h, so that most of oridonin would enter the surroundings without undergoing phagocytosis. Rat primary NSCLC models were built and administered with saline, oridonin powder, gemcitabine, and oridonin-loaded LPMPs via airway, respectively. The LPMPs showed strong anticancer effects. Oridonin showed strong angiogenesis inhibition and apoptosis. Relevant mechanisms are thought to include oridonin-induced mitochondrial dysfunction accompanied by low mitochondrial membrane potentials, downregulation of BCL-2 expressions, upregulation of expressions of BAX, caspase-3 and caspase-9. The oridonin-loaded PLGALPMPs showed high anti-NSCLC effects after pulmonary delivery. In conclusion, LPMPs are promising dry powder inhalations for in situ treatment of lung cancer.展开更多
获得在酸碱介质中稳定性好、溶胀率小的壳聚糖/PVA微粒的基础上,探讨了时间、pH、温度等因素对壳聚糖/PVA微粒吸附Cr(Ⅵ)的影响,结果表明:温度与pH是影响吸附量最主要因素。在平均粒径为200μm,最适pH=3、28℃振荡240 m in其吸附量达200...获得在酸碱介质中稳定性好、溶胀率小的壳聚糖/PVA微粒的基础上,探讨了时间、pH、温度等因素对壳聚糖/PVA微粒吸附Cr(Ⅵ)的影响,结果表明:温度与pH是影响吸附量最主要因素。在平均粒径为200μm,最适pH=3、28℃振荡240 m in其吸附量达200 mg/g以上,吸附量随温度的升高而增大。通过计算不同温度下各热力学参数ΔG、ΔH和ΔS,证实该吸附为一自发的吸热过程。对实验数据运用相关数学模型拟合,得出等温吸附平衡符合Langmuir模型,吸附过程动力学更适合二级反应。展开更多
文摘Based on the study of oxygen isotope and mi-croparticle in the Guliya ice core, atmospheric dust and en-vironmental changes in the northwest Tibetan Plateau since the last interglacial were revealed. The microparticle record indicates that low dust load on the Plateau in the interglacial. Particle concentration increased rapidly when the climate turned into the last glacial and reached the maximum during the MIS 4. In the Last Glacial Maximum, however, the en-hancement of microparticle concentration was slight, differ-ing to those in the Antarctic and Greenland. On the orbital timescale, both the temperature on the Tibetan Plateau and summer solar insolation in the Northern Hemisphere had their impact on the microparticle record, but the difference in phase and amplitude also existed. Though having the same dust source, microparticle records in the ice cores on the Tibetan Plateau and the Greenland seem to have different significance.
基金supported by the National Natural Science Foundation of China (Grant No. 81370422)
文摘Microvesicles （MVs, also known as microparticles） are small vesicles that originate from plasma membrane of almost all eukaryotic cells during apoptosis or activation. MVs can serve as extracellular vehicles to transport bioactive molecules from their parental cells to recipient target cells, thereby serving as novel mediators for intercellular communication. Importantly, more and more evidence indicates that MVs could play important roles in early pathogenesis and subsequent progression of cardiovascular and metabolic diseases. Elevated plasma concentrations of MVs, originating from red blood cells, leukocytes, platelets, or other organs and tissues, have been reported in various cardiometabolic diseases. Circulating MVs could serve as potential biomarkers for disease diagnosis or therapeutic monitoring. In this review, we summarized recently- published studies in the field and discussed the role of MVs in the pathogenesis of cardiometabolic diseases. The emerging values of MVs that serve as biomarker for non-invasive diagnosis and prog- nosis, as well as their roles as novel therapeutic targets in cardiometabolic diseases, were also described.
基金grants from the National Natural Science Foundation of China (Nos.81770356, 81470473,and 81600340)and the Capital Health Research and Development of Special (No.2016-2-4083).
文摘Background: Microparticles (MPs) are small extracellular plasma membrane particles shed by activated and apoptotic cells, which are involved in the development of atherosclerosis. Our previous study found that microRNA (miR)-19b encapsulated within endothelial MPs (EMPs) may contribute to the upregulation of circulating miR-19b in unstable angina patients. Hypoxia is involved in atherosclerosis as a critical pathological stimulus. However, it still remains unclear whether the increase of miR-19b levels in EMPs is related to hypoxia and if the effect of miR-19b - wrapped within EMPs - stimulates hypoxia on vascular endothelial cells. This study aimed to explore the changes of miR-19b in EMPs induced by hypoxia as well as their effects on endothelial cells.Methods: Human umbilical vein endothelial cells (HUVECs) were culturedin vitro and arranged to harvest EMPs in two parts: the first part consisted of EMPcontrol and EMPhypoxia and the second part included EMPvehicle, EMPNC mimic, and EMPmiR-19b mimic. Cell migration was detected by scratch migration and transwell chamber migration. Angiogenesis was assessed by tube formation assays. Furthermore, we predicted the target gene of miR-19b by bioinformatics analysis, and luciferase assay was used to verify the targeted gene of miR-19b. Data were analyzed by one-way analysis of variance. Student’st-test was used when two groups were compared.Results: Compared with EMPcontrol- and EMPhypoxia-inhibited migration of cells by scratch migration assay (80.77 ± 1.10 vs. 28.37 ± 1.40,P < 0. 001) and transwell chamber migration assay (83.00 ± 3.46 vs. 235.00 ± 16.52,P < 0.01), the number of tube formations was markedly reduced by 70% in the EMPhypoxia group (P < 0.001)in vitro analysis of HUVECs. Meanwhile, a strong inhibition of migration and tube formation of HUVECs in the presence of miR-19b-enriched EMPmiR-19b mimic was observed. This effect might be due to the delivery of miR-19b in EMPs. Transforming growth factor-β2 (TGFβ2) was predicted to be one of the target g
基金the National Natural Science Foundation of China (No. 29376233).
文摘Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scanning electronic microscopy, X-ray diffraction and infrared radiation were used to examine particle size, crystallinity and chemical structure. The results show that B-HMX microparticle in different average size (2-9.5um) and with narrow size distribution were obtained by controlling the expansibility, expansion speed, initial concentration and temperature during recrystallization of HMX. The formation of nuclei may be a main cause of consumption of solute when the solution is expanded rapidly enough and the equilibrium concentration is lower, in which almost monodisperse microparticle can be obtained.
基金This work was supported by Samsung SDI.Part of this work was performed at the Stanford Nano Shared Facilities(SNSF)Stanford Nanofabrication Facility(SNF).
文摘Nanoporous silicon is a promising anode material for high energy density batteries due to its high cycling stability and high tap density compared to other nanostructured anode materials.However,the high cost of synthesis and low yield of nanoporous silicon limit its practical application.Here,we develop a scalable,low-cost top-down process of controlled oxidation of Mg2Si in the air,followed by HCl removal of MgO to generate nanoporous silicon without the use of HF.By controlling the synthesis conditions,the oxygen content,grain size and yield of the porous silicon are simultaneously optimized from commercial standpoints.In situ environmental transmission electron microscopy reveals the reaction mechanism;the Mg2Si microparticle reacts with O2 to form MgO and Si,while preventing SiO2 formation.Owing to the low oxygen content and microscale secondary structure,the nanoporous silicon delivers a higher initial reversible capacity and initial Coulombic efficiency compared to commercial Si nanoparticles(3,033 mAh/g vs.2,418 mAh/g,84.3%vs.73.1%).Synthesis is highly scalable,and a yield of 90.4%is achieved for the porous Si nanostructure with the capability to make an excess of 10 g per batch.Our synthetic nanoporous silicon is promising for practical applications in next generation lithium-ion batteries.
基金supported in part by grants from the National Key Technologies R&D Program for New Drugs of China (No. 2012ZX09301003-001-009)the Beijing Natural Science Foundation of China (No.7154230)
文摘Non-small cell lung cancer(NSCLC) accounts for about 85% of all lung cancers. Traditional chemotherapy for this disease leads to serious side effects. Here we prepared an inhalable oridonin-loaded poly(lactic-co-glycolic)acid(PLGA) large porous microparticle(LPMP) for in situ treatment of NSCLC with the emulsion/solvent evaporation/freeze-drying method. The LPMPs were smooth spheres with many internal pores. Despite a geometric diameter of 10 mm, the aerodynamic diameter of the spheres was only 2.72 mm, leading to highly efficient lung deposition. In vitro studies showed that most of oridonin was released after 1 h, whereas the alveolar macrophage uptake of LPMPs occurred after 8 h, so that most of oridonin would enter the surroundings without undergoing phagocytosis. Rat primary NSCLC models were built and administered with saline, oridonin powder, gemcitabine, and oridonin-loaded LPMPs via airway, respectively. The LPMPs showed strong anticancer effects. Oridonin showed strong angiogenesis inhibition and apoptosis. Relevant mechanisms are thought to include oridonin-induced mitochondrial dysfunction accompanied by low mitochondrial membrane potentials, downregulation of BCL-2 expressions, upregulation of expressions of BAX, caspase-3 and caspase-9. The oridonin-loaded PLGALPMPs showed high anti-NSCLC effects after pulmonary delivery. In conclusion, LPMPs are promising dry powder inhalations for in situ treatment of lung cancer.
文摘获得在酸碱介质中稳定性好、溶胀率小的壳聚糖/PVA微粒的基础上,探讨了时间、pH、温度等因素对壳聚糖/PVA微粒吸附Cr(Ⅵ)的影响,结果表明:温度与pH是影响吸附量最主要因素。在平均粒径为200μm,最适pH=3、28℃振荡240 m in其吸附量达200 mg/g以上,吸附量随温度的升高而增大。通过计算不同温度下各热力学参数ΔG、ΔH和ΔS,证实该吸附为一自发的吸热过程。对实验数据运用相关数学模型拟合,得出等温吸附平衡符合Langmuir模型,吸附过程动力学更适合二级反应。
