BACKGROUND： Previous studies have reported a neurotrophin-like motif in the N-terminal receptor binding region of the thrombopoietin （TPO） molecule, and have described localization of TPO and TPO receptor in the br...BACKGROUND： Previous studies have reported a neurotrophin-like motif in the N-terminal receptor binding region of the thrombopoietin （TPO） molecule, and have described localization of TPO and TPO receptor in the brain. Therefore, it is believed that TPO may be involved in regulation of neurogenesis. OBJECTIVE： To validate the effect of TPO on trans-differentiation, or differentiation from hematopoietic stem cells （HSCs） to neural stem cells （NSCs）. DESIGN, TIME AND SETTING： Comparative studies were performed from March 2004 to April 2007 at the Department of Experimental Medicine, Northern Hospital, and the Department of Immunology, Fourth Military Medical University of Chinese PLA. MATERIALS： Human fetal liver （FL） was obtained from fetuses after water-balloon abortion. Gestational age ranged from 16 to 20 weeks. The study was approved by the Institutional Review Board and Ethics Committee of the Northern Hospital. TPO was kindly provided by Genentech Inc （USA）. Iscove＇s Modified Dulbecco＇s Medium （IMDM） and neurobasalTM medium were purchased from Invitrogen （USA）. MACS CD34 multisort kit was purchased from Miltenyi Biotec （Germany）. METHODS： CD34^＋ cells were isolated from human FL mononuclear cells using MACS CD34 multisort kit and cultured at 1 × 10^5/mL in IMDM, containing TPO for 60 days with weekly changes of half of the medium. After culturing for 30 and 60 days, the TPO-induced cells were resuspended in neurobasalTM medium containing 10% fetal brain extracts and plated in an 8-well BIOCOAT poly-D-Lysine Culture Slide and cultured for another 7 days. MAIN OUTCOME MEASURES： Cell number, viability, phenotype and expression of hemopoiesis-related and neurogenesis-related proteins were examined by trypan blue exclusion with hemocytometer, immunoblot, immunocytochemistry and flow cytometry. RESULTS： After 60 days of induction with TPO, the cell number increased by 4.6-fold compared to the initial culture. Although the proportion of the cells expressing the hemopoietic stem cell associated antigen （CD34） decreased steadily, both proportions of the cultured FL-derived CD34^＋cells expressing CD41a and CD61 remained unchanged, which still accounted for 10%. Noticeably, the proportions of the cells expressing nestin and epidermal growth factor receptor increased significantly （both 〉 50%）, whereas the expression of more mature neural or glial proteins [microtubule-associated protein-2 （MAP2）, glial fibrillary acidic protein （GFAP）, oligodendrocyte marker 04 （04）] markers on the cultured fetal liver derived-CD34^＋ cells were at lower levels. After another 7 days incubation in neurobasalTM medium, these TPO-induced cells formed neurospheres, which were labeled with nestin, and differentiated into cells with morphological characteristics of neurons, astrocytes and oligodendrocytes, which were labeled with MAP-2, GFAE and 04, respectively. CONCLUSION： TPO can induce FL-derived HSCs to differentiate or trans-differentiate into NSCs and its progenitors.展开更多
In plants,heteromorphic self-incompatibility(HetSI)is a strategy for avoiding self-pollination and promoting outcrossing,and during this process,numerous protein-protein interaction events occur between the pistil and...In plants,heteromorphic self-incompatibility(HetSI)is a strategy for avoiding self-pollination and promoting outcrossing,and during this process,numerous protein-protein interaction events occur between the pistil and pollen.Previous studies in Primula and Fagopyrum that focused on HetSI systems have provided interesting insights;however,the molecular mechanism underlying HetSI remains largely unknown.In this study,we profiled the proteome of Plumbago auriculata stigmas before and after self-incompatible(SI)and self-compatible(SC)pollination.Comparative analyses were conducted by 4D-DIA(Four-dimensional data independent acquisition),a promising technology that increases the sensitivity and reduces the spectral complexity of proteomic analysis by adding a fourth dimension,ion mobility.The results revealed 33387 peptides and 5311 proteins in all samples.The pathways in which the differentially expressed proteins(DEPs)identified in the P×P(Pin style self-pollinated with pin pollen)vs.PS(Pin style)and T×T(Thrum style self-pollinated with thrum pollen)vs.TS(Thrum style)comparisons were significantly enriched were biosynthesis of secondary metabolites and pentose and glucuronate interconversions.In the P×T(Pin style cross-pollinated with thrum pollen)vs.PS and T×P(Thrum style cross-pollinated with pin pollen)vs.TS comparison,the top three pathways were biosynthesis of secondary metabolites,pentose and glucuronate interconversions,and phenylpropanoid biosynthesis.The phenylpropanoid biosynthesis,cutin,suberine and wax biosynthesis,and flavonoid biosynthesis pathways were enriched in the P×T vs.P×P comparison,and starch and sucrose metabolism,glycerophospholipid metabolism,and alpha-linolenic acid metabolism were abundant in the T×T vs.T×P comparison.The enriched pathways between PS and TS were the biosynthesis of secondary metabolites,phenylpropanoid biosynthesis,and pentose and glucuronate interconversion.Self-incompatibility protein S1(SI S1),Mitogen-activated protein kinase 3/4(MPK3/4),Mitogen-activated protein kinase kinase 2/3(M2K2/3),Exocyst complex component EXO70A1(E70A1)and Thioredoxin H1/2(TRXH1/2)were found to be HetSI-related candidates,and O-fucosyltransferase 23(OFT23),3-ketoacyl-CoA synthase 6(KCS6),Receptor-like protein kinase FERONIA(FERON),Fimbrin-5(FIMB5),Pollen-specific leucine-rich repeat extensin-like protein 4(PLRX4),Transcription initiation factor IIB-2(TF2B2)and Pectinesterase 1(AL11A),etc.,were identified as other regulatory transducers.These findings combined with our morphological and reactive oxygen species(ROS)intensity analyses indicate that P.auriculata has typical dry-stigmas and that the HetSI mechanism might differ between the pin and thrum.SI S1 might be the key factor in HetSI,and ROS are overexpressed during SC pollination to rapidly activate the mitogen-activated protein kinase(MAPK)-mediated phosphorylation of E70A1 to maintain stigma receptivity in plants with HetSI.展开更多
Higher-order Poincarésphere(HOPS) beams with spatially variable polarization and phase distributions are opening up a host of unique applications in areas ranging from optical communication to microscopy.However,...Higher-order Poincarésphere(HOPS) beams with spatially variable polarization and phase distributions are opening up a host of unique applications in areas ranging from optical communication to microscopy.However, the flexible generation of these beams with high peak power from compact laser systems remains a challenge. Here, we demonstrate the controlled generation of HOPS beams based on coherent beam combination from an Yb-doped multicore fiber(MCF) amplifier. Using a spatial light modulator to adaptively adjust the wavefront and polarization of the signals seeded into the individual cores of the MCF various structured beams(including cylindrical vector beams and first-and second-order vortex beams) were generated with peak powers up to 14 k W for ~92 ps pulses.展开更多
With the abuse of antimicrobial agents in developing countries, increasing number of carbapenem- resistant Enterobacteriaceae （CRE） attracted considerable public concern. A retrospective study was conducted based on...With the abuse of antimicrobial agents in developing countries, increasing number of carbapenem- resistant Enterobacteriaceae （CRE） attracted considerable public concern. A retrospective study was conducted based on 242 CRE strains from a tertiary hospital in Hangzhou, China to investigate prevalence and drug resistance characteristics of CRE in southeast China. Bacterial species were identified. Antimicrobial susceptibility was examined by broth microdilution method or epsilometer test. Resistant [blactamase genes were identified by polymerase chain reaction and sequencing. Genotypes were investigated by phylogenetic analysis. Klebsiella pneumoniae and Escherichia coli were the most prevalent types of species, with occurrence in 71.9% and 21.9% of the strains, respectively. All strains exhibited high resistance （ 〉 70%） against [^-lactam antibiotics, ciprofloxacin, trimethoprim-sulfamethoxazole, and nitrofurantoin but exhibited low resistance against tigecycline （0.8%） and minocycline （8.3%）. A total of 123 strains harbored more than two kinds of p-lactamase genes, blaKec-2, blasHv-11, blaTEM-1, and blacTX-M-14 were the predominant genotypes, with detection rates of 60.3%, 61.6%, 43.4%, and 16.5%, respectively, and were highly identical with reference sequences in different countries, indicating potential horizontal dissemination. IMP-4 was the most frequent class B metallo-lactamases in this study. In conclusion, continuous surveillance and effective prevention should be emphasized to reduce spread of CRE.展开更多
Optical angular momentum(OAM)-based structured light beams provide an additional degree of freedom for practical applications ranging from optical communication to laser-based material processing. Many techniques exis...Optical angular momentum(OAM)-based structured light beams provide an additional degree of freedom for practical applications ranging from optical communication to laser-based material processing. Many techniques exist for generating such beams within laser sources and these primarily rely upon the use of specially designed optical components that limit laser power scaling and ready tunability of the topological charge and polarization of the output OAM beams. Here we show that some of these limitations can be overcome by employing a computer controlled reflective phase-only spatial light modulator to adaptively tailor the input(and subsequent output) beam wavefront and polarization in a few-mode fiber amplifier. In this way modal-coupling-induced beam distortion within the fiber amplifier can be mitigated and we are able to generate at will any desired supported spatial mode guided in the fiber, including conventional linearly polarized(LP) modes, scalar OAM modes, and cylindrical vector modes, at average powers >10 W and with a peak power of >11 kW. Our results pave the way to the realization of practical high-power structured laser sources with tunable chirality and polarization.展开更多
基金National Key Basic Research Program of China, No. 2001CB510004the National Natural Science Foundation of China,No.30030130
文摘BACKGROUND： Previous studies have reported a neurotrophin-like motif in the N-terminal receptor binding region of the thrombopoietin （TPO） molecule, and have described localization of TPO and TPO receptor in the brain. Therefore, it is believed that TPO may be involved in regulation of neurogenesis. OBJECTIVE： To validate the effect of TPO on trans-differentiation, or differentiation from hematopoietic stem cells （HSCs） to neural stem cells （NSCs）. DESIGN, TIME AND SETTING： Comparative studies were performed from March 2004 to April 2007 at the Department of Experimental Medicine, Northern Hospital, and the Department of Immunology, Fourth Military Medical University of Chinese PLA. MATERIALS： Human fetal liver （FL） was obtained from fetuses after water-balloon abortion. Gestational age ranged from 16 to 20 weeks. The study was approved by the Institutional Review Board and Ethics Committee of the Northern Hospital. TPO was kindly provided by Genentech Inc （USA）. Iscove＇s Modified Dulbecco＇s Medium （IMDM） and neurobasalTM medium were purchased from Invitrogen （USA）. MACS CD34 multisort kit was purchased from Miltenyi Biotec （Germany）. METHODS： CD34^＋ cells were isolated from human FL mononuclear cells using MACS CD34 multisort kit and cultured at 1 × 10^5/mL in IMDM, containing TPO for 60 days with weekly changes of half of the medium. After culturing for 30 and 60 days, the TPO-induced cells were resuspended in neurobasalTM medium containing 10% fetal brain extracts and plated in an 8-well BIOCOAT poly-D-Lysine Culture Slide and cultured for another 7 days. MAIN OUTCOME MEASURES： Cell number, viability, phenotype and expression of hemopoiesis-related and neurogenesis-related proteins were examined by trypan blue exclusion with hemocytometer, immunoblot, immunocytochemistry and flow cytometry. RESULTS： After 60 days of induction with TPO, the cell number increased by 4.6-fold compared to the initial culture. Although the proportion of the cells expressing the hemopoietic stem cell associated antigen （CD34） decreased steadily, both proportions of the cultured FL-derived CD34^＋cells expressing CD41a and CD61 remained unchanged, which still accounted for 10%. Noticeably, the proportions of the cells expressing nestin and epidermal growth factor receptor increased significantly （both 〉 50%）, whereas the expression of more mature neural or glial proteins [microtubule-associated protein-2 （MAP2）, glial fibrillary acidic protein （GFAP）, oligodendrocyte marker 04 （04）] markers on the cultured fetal liver derived-CD34^＋ cells were at lower levels. After another 7 days incubation in neurobasalTM medium, these TPO-induced cells formed neurospheres, which were labeled with nestin, and differentiated into cells with morphological characteristics of neurons, astrocytes and oligodendrocytes, which were labeled with MAP-2, GFAE and 04, respectively. CONCLUSION： TPO can induce FL-derived HSCs to differentiate or trans-differentiate into NSCs and its progenitors.
基金Scientific Research Foundation of Science&Technology Department of Sichuan Province(2021YJ0497).
文摘In plants,heteromorphic self-incompatibility(HetSI)is a strategy for avoiding self-pollination and promoting outcrossing,and during this process,numerous protein-protein interaction events occur between the pistil and pollen.Previous studies in Primula and Fagopyrum that focused on HetSI systems have provided interesting insights;however,the molecular mechanism underlying HetSI remains largely unknown.In this study,we profiled the proteome of Plumbago auriculata stigmas before and after self-incompatible(SI)and self-compatible(SC)pollination.Comparative analyses were conducted by 4D-DIA(Four-dimensional data independent acquisition),a promising technology that increases the sensitivity and reduces the spectral complexity of proteomic analysis by adding a fourth dimension,ion mobility.The results revealed 33387 peptides and 5311 proteins in all samples.The pathways in which the differentially expressed proteins(DEPs)identified in the P×P(Pin style self-pollinated with pin pollen)vs.PS(Pin style)and T×T(Thrum style self-pollinated with thrum pollen)vs.TS(Thrum style)comparisons were significantly enriched were biosynthesis of secondary metabolites and pentose and glucuronate interconversions.In the P×T(Pin style cross-pollinated with thrum pollen)vs.PS and T×P(Thrum style cross-pollinated with pin pollen)vs.TS comparison,the top three pathways were biosynthesis of secondary metabolites,pentose and glucuronate interconversions,and phenylpropanoid biosynthesis.The phenylpropanoid biosynthesis,cutin,suberine and wax biosynthesis,and flavonoid biosynthesis pathways were enriched in the P×T vs.P×P comparison,and starch and sucrose metabolism,glycerophospholipid metabolism,and alpha-linolenic acid metabolism were abundant in the T×T vs.T×P comparison.The enriched pathways between PS and TS were the biosynthesis of secondary metabolites,phenylpropanoid biosynthesis,and pentose and glucuronate interconversion.Self-incompatibility protein S1(SI S1),Mitogen-activated protein kinase 3/4(MPK3/4),Mitogen-activated protein kinase kinase 2/3(M2K2/3),Exocyst complex component EXO70A1(E70A1)and Thioredoxin H1/2(TRXH1/2)were found to be HetSI-related candidates,and O-fucosyltransferase 23(OFT23),3-ketoacyl-CoA synthase 6(KCS6),Receptor-like protein kinase FERONIA(FERON),Fimbrin-5(FIMB5),Pollen-specific leucine-rich repeat extensin-like protein 4(PLRX4),Transcription initiation factor IIB-2(TF2B2)and Pectinesterase 1(AL11A),etc.,were identified as other regulatory transducers.These findings combined with our morphological and reactive oxygen species(ROS)intensity analyses indicate that P.auriculata has typical dry-stigmas and that the HetSI mechanism might differ between the pin and thrum.SI S1 might be the key factor in HetSI,and ROS are overexpressed during SC pollination to rapidly activate the mitogen-activated protein kinase(MAPK)-mediated phosphorylation of E70A1 to maintain stigma receptivity in plants with HetSI.
基金Engineering and Physical Sciences Research Council(EP/N00762X/1,EP/P027644/1,EP/P030181/1,EP/T019441/1)H2020 European Research Council(802682)+1 种基金China Scholarship Council(202006840003)Guangdong Introducing Innovative and Entrepreneurial Teams of“The Pearl River Talent Recruitment Program”(2021ZT09X044)
文摘Higher-order Poincarésphere(HOPS) beams with spatially variable polarization and phase distributions are opening up a host of unique applications in areas ranging from optical communication to microscopy.However, the flexible generation of these beams with high peak power from compact laser systems remains a challenge. Here, we demonstrate the controlled generation of HOPS beams based on coherent beam combination from an Yb-doped multicore fiber(MCF) amplifier. Using a spatial light modulator to adaptively adjust the wavefront and polarization of the signals seeded into the individual cores of the MCF various structured beams(including cylindrical vector beams and first-and second-order vortex beams) were generated with peak powers up to 14 k W for ~92 ps pulses.
文摘With the abuse of antimicrobial agents in developing countries, increasing number of carbapenem- resistant Enterobacteriaceae （CRE） attracted considerable public concern. A retrospective study was conducted based on 242 CRE strains from a tertiary hospital in Hangzhou, China to investigate prevalence and drug resistance characteristics of CRE in southeast China. Bacterial species were identified. Antimicrobial susceptibility was examined by broth microdilution method or epsilometer test. Resistant [blactamase genes were identified by polymerase chain reaction and sequencing. Genotypes were investigated by phylogenetic analysis. Klebsiella pneumoniae and Escherichia coli were the most prevalent types of species, with occurrence in 71.9% and 21.9% of the strains, respectively. All strains exhibited high resistance （ 〉 70%） against [^-lactam antibiotics, ciprofloxacin, trimethoprim-sulfamethoxazole, and nitrofurantoin but exhibited low resistance against tigecycline （0.8%） and minocycline （8.3%）. A total of 123 strains harbored more than two kinds of p-lactamase genes, blaKec-2, blasHv-11, blaTEM-1, and blacTX-M-14 were the predominant genotypes, with detection rates of 60.3%, 61.6%, 43.4%, and 16.5%, respectively, and were highly identical with reference sequences in different countries, indicating potential horizontal dissemination. IMP-4 was the most frequent class B metallo-lactamases in this study. In conclusion, continuous surveillance and effective prevention should be emphasized to reduce spread of CRE.
基金Australian Research Council(DE180100009,DP170101400)Engineering and Physical Sciences Research Council(EP/N00762X/1,EP/P012248/1,EP/P030181/1)。
文摘Optical angular momentum(OAM)-based structured light beams provide an additional degree of freedom for practical applications ranging from optical communication to laser-based material processing. Many techniques exist for generating such beams within laser sources and these primarily rely upon the use of specially designed optical components that limit laser power scaling and ready tunability of the topological charge and polarization of the output OAM beams. Here we show that some of these limitations can be overcome by employing a computer controlled reflective phase-only spatial light modulator to adaptively tailor the input(and subsequent output) beam wavefront and polarization in a few-mode fiber amplifier. In this way modal-coupling-induced beam distortion within the fiber amplifier can be mitigated and we are able to generate at will any desired supported spatial mode guided in the fiber, including conventional linearly polarized(LP) modes, scalar OAM modes, and cylindrical vector modes, at average powers >10 W and with a peak power of >11 kW. Our results pave the way to the realization of practical high-power structured laser sources with tunable chirality and polarization.
