It is known that phosphorus can refine the primary silicon and heat treatment can spheroidize the eutectic silicon. This paper presents an optimal combination of heat treatment processes and P refinement on hypereutec...It is known that phosphorus can refine the primary silicon and heat treatment can spheroidize the eutectic silicon. This paper presents an optimal combination of heat treatment processes and P refinement on hypereutectic Al-Si alloy. The optimal P addition amount, and the solution and aging temperatures for Al-25%Si alloy were obtained through the orthogonal experiment, and their modification effects were discussed. The results show that P addition has the greatest modification effect, followed by aging temperature, and the modification effect of solution temperature is the least. The optimized modification parameters are: addition of 0.6% P, solution at 540 oC and aging at 160 oC. In addition, the cooling curve, superheating and hardness of the alloy were also analyzed.展开更多
Purpose： This study explores how search motivation and context influence mobile Web search behaviors. Design/methodology/approach： We studied 30 experienced mobile Web users via questionnaires, semi-structured inter...Purpose： This study explores how search motivation and context influence mobile Web search behaviors. Design/methodology/approach： We studied 30 experienced mobile Web users via questionnaires, semi-structured interviews, and an online diary tool that participants used to record their daily search activities. SQLite Developer was used to extract data from the users＇ phone logs for correlation analysis in Statistical Product and Service Solutions （SPSS）. Findings： One quarter of mobile search sessions were driven by two or more search motivations. It was especially difficult to distinguish curiosity from time killing in particular user reporting. Multi-dimensional contexts and motivations influenced mobile search behaviors, and among the context dimensions, gender, place, activities they engaged in while searching, task importance, portal, and interpersonal relations （whether accompanied or alone when searching） correlated with each other. Research limitations： The sample was comprised entirely of college students, so our findings may not generalize to other populations. More participants and longer experimental duration will improve the accuracy and objectivity of the research. Practical implications： Motivation analysis and search context recognition can help mobile service providers design applications and services for particular mobile contexts and usages. Originality/value： Most current research focuses on specific contexts, such as studies on place, or other contextual influences on mobile search, and lacks a systematic analysis of mobile search context. Based on analysis of the impact of mobile search motivations and search context on search behaviors, we built a multi-dimensional model of mobile search behaviors.展开更多
Elaioplasts of citrus peel are colorless plastids which accumulate significant amounts of terpenes.However,other functions of elaioplasts have not been fully characterized to date.Here,a LC–MS/MS shotgun technology w...Elaioplasts of citrus peel are colorless plastids which accumulate significant amounts of terpenes.However,other functions of elaioplasts have not been fully characterized to date.Here,a LC–MS/MS shotgun technology was applied to identify the proteins from elaioplasts that were highly purified from young fruit peel of kumquat.A total of 655 putative plastid proteins were identified from elaioplasts according to sequence homology in silico and manual curation.Based on functional classification via Mapman,~50%of the identified proteins fall into six categories,including protein metabolism,transport,and lipid metabolism.Of note,elaioplasts contained ATP synthase and ADP,ATP carrier proteins at high abundance,indicating important roles for ATP generation and transport in elaioplast biogenesis.Additionally,a comparison of proteins between citrus chromoplast and elaioplast proteomes suggest a high level of functional conservation.However,some distinctive protein profiles were also observed in both types of plastids notably for isoprene biosynthesis in elaioplasts,and carotenoid metabolism in chromoplasts.In conclusion,this comprehensive proteomic study provides new insights into the major metabolic pathways and unique characteristics of elaioplasts and chromoplasts in citrus fruit.展开更多
An insightful understanding of the formation mechanism of process-inherent defects anddeformation is increasingly important for the property evaluation and structural design of ceramicmatrix composites (CMCs). For thi...An insightful understanding of the formation mechanism of process-inherent defects anddeformation is increasingly important for the property evaluation and structural design of ceramicmatrix composites (CMCs). For this purpose, a coupled thermal–diffusive–mechanical modelingapproach was proposed by considering three important phenomena that occur during the pyrolysisprocess for manufacturing CMCs: variations of the physical and mechanical properties of theconstituents, generation and diffusive of pyrolysis gas, and multiple thermal deformations. Thesynergistic effects of these three phenomena on the stress, damage development, microstructuralmorphology, and process deformation of SiC matrix composites were investigated using finiteelement simulations. This new approach was validated by comparing the simulation and experimentalresults. Significant volume shrinkage of the matrix during the polymer-to-ceramic transformationresulted in large tensile stresses and subsequent highly fragmented microstructure in CMCs. Thepyrolysis-gas-induced expansion on the matrix under a damage state may yield a positive processdeformation of CMCs at the macroscale, overcoming the effects of the volume shrinkage of the bulkmatrix at the microscale. The modeling approach is expected to guide high-quality manufacturing ofCMCs and comprehensive studies of structure–processing–property relationships.展开更多
Chemotherapy is restricted by efficient drug outflow due to the multiple drug resistance(MDR)in heterogenous nature of tumor.Herein,we present a dual-responsive hyaluronic acid(HA)nanocomposite hydrogel that can not o...Chemotherapy is restricted by efficient drug outflow due to the multiple drug resistance(MDR)in heterogenous nature of tumor.Herein,we present a dual-responsive hyaluronic acid(HA)nanocomposite hydrogel that can not only response to the tumor microenvironment but also enhance chemotherapy.This HA hydrogel consists of a core-shell SiO_(2)(GOD@SiO_(2)-Arg)and mesoporous silica nanoparticles(MSNs)with doxorubicin(DOX)as the cargo(DOX@MSN).It could rapidly release the GOD@SiO_(2)-Arg nanoparticles at the low p H tumor-specific environment due to the cleavage of imine bond.GOD@SiO_(2)-Arg activated by over-expressed glutathione(GSH)in tumor cells releases GOD due to the cleavage of disulfide bonds,which could oxidize glucose to produce hydrogen peroxide(H2O2)for in situ NO generation via reaction between Arg and H2O2.The validity of this study might provide a method to modulate the tumor microenvironment for enhancing chemotherapy.展开更多
In the present study,we investigate the crystal structure of high-entropy alloys(HEAs)in the form of CoFe2NiMn0.3AlCux(x=0.25,0.50,0.75,and 1.00)and their mechanical and magnetic properties.The CoFe2NiMn0.3AlCux alloy...In the present study,we investigate the crystal structure of high-entropy alloys(HEAs)in the form of CoFe2NiMn0.3AlCux(x=0.25,0.50,0.75,and 1.00)and their mechanical and magnetic properties.The CoFe2NiMn0.3AlCux alloys are composed of a mixture of a body-centered cubic(BCC)and a face-centered cubic(FCC)solid solution.The increased amounts of copper(Cu)boost both alloy strength and plastic ductility.The CoFe2 NiMn0.3AlCu1.0 HEAs demonstrate excellent mechanical properties,such as a high strength of 1832 MPa and a large plastic ductility of 22.38%.Magnetic property measurements on this alloy system indicated high saturated magnetization and high coercivity.The coercivity of the tested alloys lies in the range between 40 and 182 Oe,suggesting that the alloys have semi-hard magnetic properties.This study suggests that the present CoFe2NiMn0.3AlCux HEAs could serve as potential candidates for soft magnets in electromagnetic applications.展开更多
Chemosensation is indispensable for the survival of Caenorhabditis elegans to discriminate food and pathogenic bacteria in their living environment. Food-like odors emitted by the pathogen Bacillus nematocida B16 for ...Chemosensation is indispensable for the survival of Caenorhabditis elegans to discriminate food and pathogenic bacteria in their living environment. Food-like odors emitted by the pathogen Bacillus nematocida B16 for trapping its hosts and an olfactory signaling pathway responsible to sense the attractant 2-heptanone were identified in our previous study. Here, we further explore how the worms recognize the attractive molecules indole and 2-ethyl hexanol, which have different chemical properties and modest nematode-luring ability. We show that the chemotaxis toward indole and 2-ethyl hexanol requires the G protein-coupled receptors encoded by str-193 on AWC and str-7 on AWA. In a further genetic screen for downstream effectors in olfactory signaling cascades, the Gα subunit GSA-1, guanylyl cyclase ODR-1 and DAF-11 and the c GMP-gated channel TAX-2/TAX-4 were found to be necessary for indole sensation, whereas the TRPV channels OSM-9/OCR-2 and the PLC pathway activated by GPA-6 are responsible for the detection of 2-ethyl hexanol. Altogether, our current work further clarifies the distinct olfactory signaling pathways through which C. elegans senses different chemicals and is lured by B. nematocida B16, improving our comprehensive understanding of the mechanisms by which bacterial pathogens effectively infect their hosts.展开更多
To the Editor:Proteolysis Targeting Chimera(PROTAC)is an emerging approach to selectively degrading target proteins by utilizing endogenous proteasome.Since PROTACs can degrade target proteins without high affinity,it...To the Editor:Proteolysis Targeting Chimera(PROTAC)is an emerging approach to selectively degrading target proteins by utilizing endogenous proteasome.Since PROTACs can degrade target proteins without high affinity,it is natural to speculate that this technology can be used to identify the targets of natural products。Although a recent study reported the employment of PROTACs to explore the unknown non-kinase target of a multi-kinase inhibitor sorafenib,whether PROTACs can be used to find the potential targets of natural products remains unexplored.展开更多
Hepatocellular carcinoma (HCC) remains a challenging disease with a high recurrence rate after surgery and there is an imminent need to identify new treatments. Currently, adjuvant therapy like chemotherapeutics arise...Hepatocellular carcinoma (HCC) remains a challenging disease with a high recurrence rate after surgery and there is an imminent need to identify new treatments. Currently, adjuvant therapy like chemotherapeutics arises to counteract the malignant trait escaping from apoptosis of tumors induced by overexpressed anti-apoptotic factors in HCC. Myeloid cell leukaemia-1 (Mcl-1) as an anti-apoptotic member of Bcl-2 is highly expressed in diverse human cancers, which contributes to cancer cell survival and the resistance to diverse chemotherapeutic agents. It is confirmed that Mcl-1 protein expression is quite enhanced in human HCC tissue compared to adjacent non-tumor tissue. Correspondingly, forced Mcl-1 down-regulation leads to prominent apoptosis of HCC cells and a sensitization towards chemotherapeutic drug-induced apoptosis, which indicates Mcl-1 is indeed a crucial regulatory factor of HCC. Hence, this review highlights the function of Mcl-1 on HCC progression, how it is regulated in HCC and the recent anti-hepatoma drug research and development down-regulation of Mcl-1 or targeting on Mcl-1. Meanwhile, the authors discuss Mcl-1 as an essential regulatory factor in HCC can be designed as target for drugs to improve the survival of HCC patients.展开更多
基金Projects(51301125,51171136,51502234,51401156,11404251)supported by the National Natural Science Foundation of ChinaProject(2013JK0907)supported by Scientific Research Program Funded by Shaanxi Provincial Education Department,China
基金financially supported by the National Natural Science Foundation of China(Nos.51401156,51371133 and 51671151)the Science and Technology Program of Shaanxi Province(No.2016KJXX-87)
文摘It is known that phosphorus can refine the primary silicon and heat treatment can spheroidize the eutectic silicon. This paper presents an optimal combination of heat treatment processes and P refinement on hypereutectic Al-Si alloy. The optimal P addition amount, and the solution and aging temperatures for Al-25%Si alloy were obtained through the orthogonal experiment, and their modification effects were discussed. The results show that P addition has the greatest modification effect, followed by aging temperature, and the modification effect of solution temperature is the least. The optimized modification parameters are: addition of 0.6% P, solution at 540 oC and aging at 160 oC. In addition, the cooling curve, superheating and hardness of the alloy were also analyzed.
基金supported by the Wuhan International Science and Technology Cooperation Fund (Grant No.:2015030809020371)the Wuhan University Youth Fund of Humanities and Social Sciences
文摘Purpose： This study explores how search motivation and context influence mobile Web search behaviors. Design/methodology/approach： We studied 30 experienced mobile Web users via questionnaires, semi-structured interviews, and an online diary tool that participants used to record their daily search activities. SQLite Developer was used to extract data from the users＇ phone logs for correlation analysis in Statistical Product and Service Solutions （SPSS）. Findings： One quarter of mobile search sessions were driven by two or more search motivations. It was especially difficult to distinguish curiosity from time killing in particular user reporting. Multi-dimensional contexts and motivations influenced mobile search behaviors, and among the context dimensions, gender, place, activities they engaged in while searching, task importance, portal, and interpersonal relations （whether accompanied or alone when searching） correlated with each other. Research limitations： The sample was comprised entirely of college students, so our findings may not generalize to other populations. More participants and longer experimental duration will improve the accuracy and objectivity of the research. Practical implications： Motivation analysis and search context recognition can help mobile service providers design applications and services for particular mobile contexts and usages. Originality/value： Most current research focuses on specific contexts, such as studies on place, or other contextual influences on mobile search, and lacks a systematic analysis of mobile search context. Based on analysis of the impact of mobile search motivations and search context on search behaviors, we built a multi-dimensional model of mobile search behaviors.
基金This work was supported by the National Natural Science Foundation of China(NSFC,grant nos.31501739)the National Basic Research Program of China(973 project No.2013CB127105)Huazhong Agricultural University Scientific&Technological Self-innovation Foundation(No.2662015BQ034).
文摘Elaioplasts of citrus peel are colorless plastids which accumulate significant amounts of terpenes.However,other functions of elaioplasts have not been fully characterized to date.Here,a LC–MS/MS shotgun technology was applied to identify the proteins from elaioplasts that were highly purified from young fruit peel of kumquat.A total of 655 putative plastid proteins were identified from elaioplasts according to sequence homology in silico and manual curation.Based on functional classification via Mapman,~50%of the identified proteins fall into six categories,including protein metabolism,transport,and lipid metabolism.Of note,elaioplasts contained ATP synthase and ADP,ATP carrier proteins at high abundance,indicating important roles for ATP generation and transport in elaioplast biogenesis.Additionally,a comparison of proteins between citrus chromoplast and elaioplast proteomes suggest a high level of functional conservation.However,some distinctive protein profiles were also observed in both types of plastids notably for isoprene biosynthesis in elaioplasts,and carotenoid metabolism in chromoplasts.In conclusion,this comprehensive proteomic study provides new insights into the major metabolic pathways and unique characteristics of elaioplasts and chromoplasts in citrus fruit.
基金The research is supported in part by the National Key R&D Program of China(No.2021YFF0501800)in part by the National Natural Science Foundation of China(Nos.12272174,12102179,and U22B6009)+1 种基金Natural Science Foundation of Jiangsu Province(No.BK20200409)the High Level Personnel Project of Jiangsu Province(No.JSSCBS20210618).
文摘An insightful understanding of the formation mechanism of process-inherent defects anddeformation is increasingly important for the property evaluation and structural design of ceramicmatrix composites (CMCs). For this purpose, a coupled thermal–diffusive–mechanical modelingapproach was proposed by considering three important phenomena that occur during the pyrolysisprocess for manufacturing CMCs: variations of the physical and mechanical properties of theconstituents, generation and diffusive of pyrolysis gas, and multiple thermal deformations. Thesynergistic effects of these three phenomena on the stress, damage development, microstructuralmorphology, and process deformation of SiC matrix composites were investigated using finiteelement simulations. This new approach was validated by comparing the simulation and experimentalresults. Significant volume shrinkage of the matrix during the polymer-to-ceramic transformationresulted in large tensile stresses and subsequent highly fragmented microstructure in CMCs. Thepyrolysis-gas-induced expansion on the matrix under a damage state may yield a positive processdeformation of CMCs at the macroscale, overcoming the effects of the volume shrinkage of the bulkmatrix at the microscale. The modeling approach is expected to guide high-quality manufacturing ofCMCs and comprehensive studies of structure–processing–property relationships.
基金supported by Sichuan Science and Technology Program(No.2022NSFSC0363)the Introduction Program of Scientific Researcher of Sichuan University of Science&Engineering(No.2020RC40)Key Laboratories of Fine Chemicals and Surfactants in Sichuan Provincial Universities(No.2020JXY02)。
文摘Chemotherapy is restricted by efficient drug outflow due to the multiple drug resistance(MDR)in heterogenous nature of tumor.Herein,we present a dual-responsive hyaluronic acid(HA)nanocomposite hydrogel that can not only response to the tumor microenvironment but also enhance chemotherapy.This HA hydrogel consists of a core-shell SiO_(2)(GOD@SiO_(2)-Arg)and mesoporous silica nanoparticles(MSNs)with doxorubicin(DOX)as the cargo(DOX@MSN).It could rapidly release the GOD@SiO_(2)-Arg nanoparticles at the low p H tumor-specific environment due to the cleavage of imine bond.GOD@SiO_(2)-Arg activated by over-expressed glutathione(GSH)in tumor cells releases GOD due to the cleavage of disulfide bonds,which could oxidize glucose to produce hydrogen peroxide(H2O2)for in situ NO generation via reaction between Arg and H2O2.The validity of this study might provide a method to modulate the tumor microenvironment for enhancing chemotherapy.
基金financially supported by the National Natural Science Foundation of China(Nos.51301125,51971166,and 51904218)the Natural Science Basic Research Program of Shaanxi Province(No.2020JM-557)the State Key Laboratory of Solidification Processing in NWPU(No.SKLSP201811)。
文摘In the present study,we investigate the crystal structure of high-entropy alloys(HEAs)in the form of CoFe2NiMn0.3AlCux(x=0.25,0.50,0.75,and 1.00)and their mechanical and magnetic properties.The CoFe2NiMn0.3AlCux alloys are composed of a mixture of a body-centered cubic(BCC)and a face-centered cubic(FCC)solid solution.The increased amounts of copper(Cu)boost both alloy strength and plastic ductility.The CoFe2 NiMn0.3AlCu1.0 HEAs demonstrate excellent mechanical properties,such as a high strength of 1832 MPa and a large plastic ductility of 22.38%.Magnetic property measurements on this alloy system indicated high saturated magnetization and high coercivity.The coercivity of the tested alloys lies in the range between 40 and 182 Oe,suggesting that the alloys have semi-hard magnetic properties.This study suggests that the present CoFe2NiMn0.3AlCux HEAs could serve as potential candidates for soft magnets in electromagnetic applications.
基金supported by the Department of Science and Technology of Yunnan Province (2019FA046)the National Natural Science Foundation of China (32060632 and 31370162)
文摘Chemosensation is indispensable for the survival of Caenorhabditis elegans to discriminate food and pathogenic bacteria in their living environment. Food-like odors emitted by the pathogen Bacillus nematocida B16 for trapping its hosts and an olfactory signaling pathway responsible to sense the attractant 2-heptanone were identified in our previous study. Here, we further explore how the worms recognize the attractive molecules indole and 2-ethyl hexanol, which have different chemical properties and modest nematode-luring ability. We show that the chemotaxis toward indole and 2-ethyl hexanol requires the G protein-coupled receptors encoded by str-193 on AWC and str-7 on AWA. In a further genetic screen for downstream effectors in olfactory signaling cascades, the Gα subunit GSA-1, guanylyl cyclase ODR-1 and DAF-11 and the c GMP-gated channel TAX-2/TAX-4 were found to be necessary for indole sensation, whereas the TRPV channels OSM-9/OCR-2 and the PLC pathway activated by GPA-6 are responsible for the detection of 2-ethyl hexanol. Altogether, our current work further clarifies the distinct olfactory signaling pathways through which C. elegans senses different chemicals and is lured by B. nematocida B16, improving our comprehensive understanding of the mechanisms by which bacterial pathogens effectively infect their hosts.
基金supported by National Natural Science Foundation of China (NSFC) (No. 82141216)Chunhui Program-Cooperative Research Project of the Ministry of Education, Liaoning Province Natural Science Foundation (No. 2020-MZLH-31, China)Shenyang Young and Middle-aged Innovative Talents Support Program (RC210446, China)
文摘To the Editor:Proteolysis Targeting Chimera(PROTAC)is an emerging approach to selectively degrading target proteins by utilizing endogenous proteasome.Since PROTACs can degrade target proteins without high affinity,it is natural to speculate that this technology can be used to identify the targets of natural products。Although a recent study reported the employment of PROTACs to explore the unknown non-kinase target of a multi-kinase inhibitor sorafenib,whether PROTACs can be used to find the potential targets of natural products remains unexplored.
基金the National Natural Science Foundation of China(Grant no.81370088)the Fundamental Research Funds for the Central Universities of Zhuizong.
文摘Hepatocellular carcinoma (HCC) remains a challenging disease with a high recurrence rate after surgery and there is an imminent need to identify new treatments. Currently, adjuvant therapy like chemotherapeutics arises to counteract the malignant trait escaping from apoptosis of tumors induced by overexpressed anti-apoptotic factors in HCC. Myeloid cell leukaemia-1 (Mcl-1) as an anti-apoptotic member of Bcl-2 is highly expressed in diverse human cancers, which contributes to cancer cell survival and the resistance to diverse chemotherapeutic agents. It is confirmed that Mcl-1 protein expression is quite enhanced in human HCC tissue compared to adjacent non-tumor tissue. Correspondingly, forced Mcl-1 down-regulation leads to prominent apoptosis of HCC cells and a sensitization towards chemotherapeutic drug-induced apoptosis, which indicates Mcl-1 is indeed a crucial regulatory factor of HCC. Hence, this review highlights the function of Mcl-1 on HCC progression, how it is regulated in HCC and the recent anti-hepatoma drug research and development down-regulation of Mcl-1 or targeting on Mcl-1. Meanwhile, the authors discuss Mcl-1 as an essential regulatory factor in HCC can be designed as target for drugs to improve the survival of HCC patients.
