A heterojunction structure design is a very good method for improving the properties of semiconductors in many research fields.This method is employed in the present study to promote the gas-sensing performance of Ag_...A heterojunction structure design is a very good method for improving the properties of semiconductors in many research fields.This method is employed in the present study to promote the gas-sensing performance of Ag_(3)PO_(4)nanocomposites at room temperature(25℃).A nanocomposite of Ag_(3)PO_(4)nanoparticles and three-dimensional peony-like WO_(3)(WO_(3)/Ag_(3)PO_(4))was successfully prepared by the precipitation method.The crystalline phases were analyzed by xray diffraction and the microstructure was characterized by scanning electron microscopy and transmission electron microscopy.The chemical bonding states were analyzed by x-ray photoelectron spectroscopy.The gas-sensing performance of WO_(3)/Ag_(3)PO_(4)sensors was systematically explored at room temperature.The composite sensors possessed a higher response and lower detection limit(1 ppm)to NH_(3)than those made of a single type of material;this is ascribed to the synergistic effect achieved by the heterojunction structure.Among the different composite sensors tested,gas sensor A5W5(Ag_(3)PO_(4):WO3mass ratio of 5:5)displayed the highest response to NH_(3)at room temperature.Interestingly,the A5W5 gas sensor exhibited relatively good stability and excellent selectivity to NH_(3).The A5W5 sensor also displayed a relatively good response under high humidity.The gas-sensing mechanism of the WO_(3)/Ag_(3)PO_(4)sensors is explained in detail.Taken together,the as-prepared sensor is highly efficient at detecting NH_(3)and could be suitable for practical applications.In addition,this study also provides a new method for developing Ag_(3)PO_(4)-based sensors in the gas-sensing field.展开更多
We investigate the angular dependence of proton-induced single event transient(SET) in silicon-germanium heterojunction bipolar transistors. Experimental results show that the overall SET cross section is almost indep...We investigate the angular dependence of proton-induced single event transient(SET) in silicon-germanium heterojunction bipolar transistors. Experimental results show that the overall SET cross section is almost independent of proton incident angle. However, the proportion of SET events with long duration and high integral charge collection grows significantly with the increasing angle. Monte Carlo simulations demonstrate that the integral cross section of proton incident events with high ionizing energy deposition in the sensitive volume tends to be higher at larger incident angles, which is associated with the angular distribution of proton-induced secondary particles and the geometry of sensitive volume.展开更多
In this paper, we investigate the space of <em>L<sup>p</sup> p</em>-harmonic 1-forms on a complete noncompact orientable <em>δ</em>-stable hypersurface <em>M<sup>m</...In this paper, we investigate the space of <em>L<sup>p</sup> p</em>-harmonic 1-forms on a complete noncompact orientable <em>δ</em>-stable hypersurface <em>M<sup>m</sup></em> that is immersed in space form <img src="Edit_6fbc11b9-ac23-40e2-b045-0fb25419337d.png" width="35" height="23" alt="" /> with nonnegative BiRic curvature. We prove the nonexistence of <em>L<sup>p</sup> p</em>-harmonic 1-forms on <em>M<sup>m</sup></em>. Moreover, we obtain some vanishing properties for this class of harmonic 1-forms.展开更多
Granulocyte colony-stimulating factor (G-CSF) is an essential regulator of neutrophil trafficking and is highly expressed in multiple tumors. Myeloid derived suppressor cells (MDSCs) promote neoplastic progression...Granulocyte colony-stimulating factor (G-CSF) is an essential regulator of neutrophil trafficking and is highly expressed in multiple tumors. Myeloid derived suppressor cells (MDSCs) promote neoplastic progression through multiple mechanisms by immune suppression. Despite the findings of G-CSF function in colon cancer progression, the precise mechanism of G-CSF on MDSCs regulation and its blockade effects on tumor growth remains a worthy area of investigation. In this study we observed an overexpression of G-CSF in a mouse colitis-associated cancer (CAC) model, which was consistent with the accumulation of MDSCs in mouse colon tissues. Further in vitro studies demonstrated that G-CSF could promote MDSCs survival and activation through signal transducer and activator of transcription 3 (STAT3) signaling pathway. Moreover, compared with isotype control, anti-G-CSF mAb treatment demonstrated reduced MDSC accumulation, which led to a marked decrease in neoplasm size and number in mice. Our results indicated that G-CSF is a critical regulating molecule in the migration, proliferation and function maintenance of MDSCs, which could be a potential therapeutic target for cancer.展开更多
基金financial support from the Collaborative Education Project of IndustryUniversity Cooperation of the Ministry of Education of China(Grant No.202101256024)the National Natural Science Foundation of China(Grant Nos.11904209 and 61802144)。
文摘A heterojunction structure design is a very good method for improving the properties of semiconductors in many research fields.This method is employed in the present study to promote the gas-sensing performance of Ag_(3)PO_(4)nanocomposites at room temperature(25℃).A nanocomposite of Ag_(3)PO_(4)nanoparticles and three-dimensional peony-like WO_(3)(WO_(3)/Ag_(3)PO_(4))was successfully prepared by the precipitation method.The crystalline phases were analyzed by xray diffraction and the microstructure was characterized by scanning electron microscopy and transmission electron microscopy.The chemical bonding states were analyzed by x-ray photoelectron spectroscopy.The gas-sensing performance of WO_(3)/Ag_(3)PO_(4)sensors was systematically explored at room temperature.The composite sensors possessed a higher response and lower detection limit(1 ppm)to NH_(3)than those made of a single type of material;this is ascribed to the synergistic effect achieved by the heterojunction structure.Among the different composite sensors tested,gas sensor A5W5(Ag_(3)PO_(4):WO3mass ratio of 5:5)displayed the highest response to NH_(3)at room temperature.Interestingly,the A5W5 gas sensor exhibited relatively good stability and excellent selectivity to NH_(3).The A5W5 sensor also displayed a relatively good response under high humidity.The gas-sensing mechanism of the WO_(3)/Ag_(3)PO_(4)sensors is explained in detail.Taken together,the as-prepared sensor is highly efficient at detecting NH_(3)and could be suitable for practical applications.In addition,this study also provides a new method for developing Ag_(3)PO_(4)-based sensors in the gas-sensing field.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11775167 and 12105252)the Natural Science Foundation of Chongqing,China(Grant No.cstc2021jcyj-bsh0246)。
文摘We investigate the angular dependence of proton-induced single event transient(SET) in silicon-germanium heterojunction bipolar transistors. Experimental results show that the overall SET cross section is almost independent of proton incident angle. However, the proportion of SET events with long duration and high integral charge collection grows significantly with the increasing angle. Monte Carlo simulations demonstrate that the integral cross section of proton incident events with high ionizing energy deposition in the sensitive volume tends to be higher at larger incident angles, which is associated with the angular distribution of proton-induced secondary particles and the geometry of sensitive volume.
文摘In this paper, we investigate the space of <em>L<sup>p</sup> p</em>-harmonic 1-forms on a complete noncompact orientable <em>δ</em>-stable hypersurface <em>M<sup>m</sup></em> that is immersed in space form <img src="Edit_6fbc11b9-ac23-40e2-b045-0fb25419337d.png" width="35" height="23" alt="" /> with nonnegative BiRic curvature. We prove the nonexistence of <em>L<sup>p</sup> p</em>-harmonic 1-forms on <em>M<sup>m</sup></em>. Moreover, we obtain some vanishing properties for this class of harmonic 1-forms.
基金We thank all study participants for their contributions to this project. This work was supported by the National Basic Research Program (973 Program) (No. 2014CB542103), Beijing Natural Science Foundation of China (Grant no.7144237), The Beijing Training Project for The Leading Talents (Z131107000513001), Beijing Nova Program (Z131107000413066) and the National Natural Science Foundation of China (Grant No. 81541154).
文摘Granulocyte colony-stimulating factor (G-CSF) is an essential regulator of neutrophil trafficking and is highly expressed in multiple tumors. Myeloid derived suppressor cells (MDSCs) promote neoplastic progression through multiple mechanisms by immune suppression. Despite the findings of G-CSF function in colon cancer progression, the precise mechanism of G-CSF on MDSCs regulation and its blockade effects on tumor growth remains a worthy area of investigation. In this study we observed an overexpression of G-CSF in a mouse colitis-associated cancer (CAC) model, which was consistent with the accumulation of MDSCs in mouse colon tissues. Further in vitro studies demonstrated that G-CSF could promote MDSCs survival and activation through signal transducer and activator of transcription 3 (STAT3) signaling pathway. Moreover, compared with isotype control, anti-G-CSF mAb treatment demonstrated reduced MDSC accumulation, which led to a marked decrease in neoplasm size and number in mice. Our results indicated that G-CSF is a critical regulating molecule in the migration, proliferation and function maintenance of MDSCs, which could be a potential therapeutic target for cancer.