BACKGROUND Colorectal cancer(CRC)is among the most prevalent and life-threatening malignancies worldwide.Syndecan-2 methylation(mSDC2)testing has emerged as a widely used biomarker for early detection of CRC in stool ...BACKGROUND Colorectal cancer(CRC)is among the most prevalent and life-threatening malignancies worldwide.Syndecan-2 methylation(mSDC2)testing has emerged as a widely used biomarker for early detection of CRC in stool and serum samples.Cancer(CRC)is among the most prevalent and life-threatening malignancies worldwide.mSDC2 testing has emerged as a widely used biomarker for early detection of CRC in stool and serum samples.AIM To validate the effectiveness of fecal DNA mSDC2 testing in the detection of CRC among a high-risk Chinese population to provide evidence-based data for the development of diagnostic and/or screening guidelines for CRC in China.METHODS A high-risk Chinese cohort consisting of 1130 individuals aged 40-79 years was selected for evaluation via fecal mSDC2 testing.Sensitivity and specificity for CRC,advanced adenoma(AA)and advanced colorectal neoplasia(ACN)were determined.High-risk factors for the incidence of colorectal lesions were determined and a logistic regression model was constructed to reflect the efficacy of the test.RESULTS A total of 1035 high-risk individuals were included in this study according to established criteria.Among them,16 suffered from CRC(1.55%),65 from AA(6.28%)and 189 from non-AAs(18.26%);150 patients were diagnosed with polyps(14.49%).Diagnoses were established based upon colonoscopic and pathological examinations.Sensitivities of the mSDC2 test for CRC and AA were 87.50%and 40.00%,respectively;specificities were 95.61%for other groups.Positive predictive values of the mSDC2 test for CRC,AA and ACN were 16.09%,29.89%and 45.98%,respectively;the negative predictive value for CRC was 99.79%.After adjusting for other high-risk covariates,mSDC2 test positivity was found to be a significant risk factor for the occurrence of ACN(P<0.001).CONCLUSION Our findings confirmed that offering fecal mSDC2 testing and colonoscopy in combination for CRC screening is effective for earlier detection of malignant colorectal lesions in a high-risk Chinese population.展开更多
BACKGROUND Treatments utilizing stems cells often require stem cells to be exposed to inflammatory environments,but the effects of such environments are unknown.AIM To examine the effects of inflammatory cytokines on ...BACKGROUND Treatments utilizing stems cells often require stem cells to be exposed to inflammatory environments,but the effects of such environments are unknown.AIM To examine the effects of inflammatory cytokines on the morphology and quantity of mesenchymal stem cell exosomes(MSCs-exo)as well as the differential expression of microRNAs(miRNAs)in the exosomes.METHODS MSCs were isolated from human umbilical tissue by enzymatic digestion.Exosomes were then collected after a 48-h incubation period in a serum-free medium with one of the following the inflammatory cytokines:None(control),vascular cell adhesion molecule-1(VCAM-1),tumor necrosis factor(TNF)α,and interleukin(IL)6.The morphology and quantity of each group of MSC exosomes were observed and measured.The miRNAs in MSCs-exo were sequenced.We compared the sequenced data with the miRBase and other non-coding databases in order to detect differentially expressed miRNAs and explore their target genes and regulatory mechanisms.In vitro tube formation assays and Western blot were performed in endothelial cells which were used to assess the angiogenic potential of MSCs-exo after inflammatory cytokine stimulation.RESULTS MSCs-exo were numerous,small,and regularly shaped in the VCAM-1 group.TNFαstimulated MSCs to secrete larger and irregular exosomes.IL6 led to a reduced quantity of MSCs-exo.Compared to the control group,the TNFαand IL6 groups had more downregulated differentially expressed miRNAs,particularly angiogenesis-related miRNAs.The angiogenic potential of MSCs-exo declined after IL6 stimulation.CONCLUSION TNFαand IL6 may influence the expression of miRNAs that down-regulate the PI3K-AKT,MAPK,and VEGF signaling pathways;particularly,IL6 significantly down-regulates the PI3K-AKT signaling pathway.Overall,inflammatory cytokines may lead to changes in exosomal miRNAs that abnormally impact cellular components,molecular function,and biological processes.展开更多
Fe-rich intermetallics, especially β-Fe phase, usually forming in the microstructure of cast aluminum alloys, are very detrimental to mechanical properties. In the present work, the effects of Fe content on phase tra...Fe-rich intermetallics, especially β-Fe phase, usually forming in the microstructure of cast aluminum alloys, are very detrimental to mechanical properties. In the present work, the effects of Fe content on phase transformation and microstructures were analyzed using a 3D X-ray microscope. Based on the highresolution 3D X-ray computed tomography, the 3D characteristics of Fe-rich intermetallics and micropores in the gravity-cast Al-6 Si alloys with different Fe contents were investigated. In addition, the effect of intermetallics on the microporosity was discussed. The results show that with increasing the Fe content from 0.10 wt.% to 0.60 wt.%, the volume fraction of Fe-rich intermetallics and the volume of the largest size Fe-rich intermetallic increased, and the 3D morphology of intermetallics changed from fine flake to network aggregation. As the Fe contents increased, the shrinkage pores were characterized, which were rather complex due to the micropores promoted by the intermetallics interactions.展开更多
We present quasi-simultaneous VLBI images of the GHz-Peaked-Spectrum radio source OQ 208 obtained with the Very Long Baseline Array at 1.4, 1.7, 2.3, 5.0, 8.4, 15.4 GHz and the European VLBI Network at 6.7 GHz. The lo...We present quasi-simultaneous VLBI images of the GHz-Peaked-Spectrum radio source OQ 208 obtained with the Very Long Baseline Array at 1.4, 1.7, 2.3, 5.0, 8.4, 15.4 GHz and the European VLBI Network at 6.7 GHz. The low frequency (1.4, 1.7 and 2.3 GHz) observations reveal a weak and extended steep-spectrum component at about 30 mas away at position angle - 110°, which may be a remnant emission. The radio structure of OQ 208 consists of two mini-lobes at 5.0, 6.7, 8.4 and 15.4 GHz. Our spectral analysis further confirms that the southwest lobe undergoes free-free absorption and finds that the free-free absorption is stronger in the inner region. By fitting the 8.4 GHz images from 1994 to 2005, we obtain a separation speed of 0.0314-0.006 mas yr^-1 between the two mini-lobes. This indicates a jet proper motion of 0.1054-0.020 c and a kinematic age of 219±42 yr for the radio source.展开更多
An efficient zinc-catalyzed oxidative cyclization of readily available indoly ynamides has been developed,enabling rapid and practical access to a diverse array of valuable medium-sized lactams in mostly good to excel...An efficient zinc-catalyzed oxidative cyclization of readily available indoly ynamides has been developed,enabling rapid and practical access to a diverse array of valuable medium-sized lactams in mostly good to excellent yields with wide substrate scope.In addition,such an asymmetric synthesis has also been explored by employing the chiral substrate.展开更多
Summary of main observation and conclusion An efficient copper-catalyzed carbocyclization of silyl enol ether tethered ynamides has been developed,allowing rapid and practical construction of diverse 2-azabicyclo[3.2....Summary of main observation and conclusion An efficient copper-catalyzed carbocyclization of silyl enol ether tethered ynamides has been developed,allowing rapid and practical construction of diverse 2-azabicyclo[3.2.0]compounds in generally good to excellent yields with broad substrate scope under mild reaction conditions.Importantly,this protocol not only constitutes a rare example of non-noble metal-catalyzed alkyne carbocyclization,but also represents a rare cyclization on the B-position ofπu-tethered ynamides.The possibility of asymmetric carbocyclization via kinetic resolution also emerges.展开更多
基金Supported by the Science and Technology Program of Panyu Central Hospital,No.PY-2023-003the Science and Technology Program of Panyu,No.2020-Z04-054+4 种基金the Science and Technology Project of the Guangzhou Health Commission,No.20211A011114the Science and Technology Program of Guangzhou,No.202002020023the General University Youth Innovative Talent Project of Guangdong Province,No.2022KQNCX281the Guangdong Provincial Key Field Special Project for Ordinary Colleges and Universities,No.2023ZDZX2097the Foshan Engineering Technology Research Center for Prepared Food Processing and Quality Evaluation,No.2022-KJZX113.
文摘BACKGROUND Colorectal cancer(CRC)is among the most prevalent and life-threatening malignancies worldwide.Syndecan-2 methylation(mSDC2)testing has emerged as a widely used biomarker for early detection of CRC in stool and serum samples.Cancer(CRC)is among the most prevalent and life-threatening malignancies worldwide.mSDC2 testing has emerged as a widely used biomarker for early detection of CRC in stool and serum samples.AIM To validate the effectiveness of fecal DNA mSDC2 testing in the detection of CRC among a high-risk Chinese population to provide evidence-based data for the development of diagnostic and/or screening guidelines for CRC in China.METHODS A high-risk Chinese cohort consisting of 1130 individuals aged 40-79 years was selected for evaluation via fecal mSDC2 testing.Sensitivity and specificity for CRC,advanced adenoma(AA)and advanced colorectal neoplasia(ACN)were determined.High-risk factors for the incidence of colorectal lesions were determined and a logistic regression model was constructed to reflect the efficacy of the test.RESULTS A total of 1035 high-risk individuals were included in this study according to established criteria.Among them,16 suffered from CRC(1.55%),65 from AA(6.28%)and 189 from non-AAs(18.26%);150 patients were diagnosed with polyps(14.49%).Diagnoses were established based upon colonoscopic and pathological examinations.Sensitivities of the mSDC2 test for CRC and AA were 87.50%and 40.00%,respectively;specificities were 95.61%for other groups.Positive predictive values of the mSDC2 test for CRC,AA and ACN were 16.09%,29.89%and 45.98%,respectively;the negative predictive value for CRC was 99.79%.After adjusting for other high-risk covariates,mSDC2 test positivity was found to be a significant risk factor for the occurrence of ACN(P<0.001).CONCLUSION Our findings confirmed that offering fecal mSDC2 testing and colonoscopy in combination for CRC screening is effective for earlier detection of malignant colorectal lesions in a high-risk Chinese population.
基金Supported by Panyu Science and Technology Plan Medical General Project,No.2018-Z04-47Guangzhou Health Science and Technology Project,No.20191A011120
文摘BACKGROUND Treatments utilizing stems cells often require stem cells to be exposed to inflammatory environments,but the effects of such environments are unknown.AIM To examine the effects of inflammatory cytokines on the morphology and quantity of mesenchymal stem cell exosomes(MSCs-exo)as well as the differential expression of microRNAs(miRNAs)in the exosomes.METHODS MSCs were isolated from human umbilical tissue by enzymatic digestion.Exosomes were then collected after a 48-h incubation period in a serum-free medium with one of the following the inflammatory cytokines:None(control),vascular cell adhesion molecule-1(VCAM-1),tumor necrosis factor(TNF)α,and interleukin(IL)6.The morphology and quantity of each group of MSC exosomes were observed and measured.The miRNAs in MSCs-exo were sequenced.We compared the sequenced data with the miRBase and other non-coding databases in order to detect differentially expressed miRNAs and explore their target genes and regulatory mechanisms.In vitro tube formation assays and Western blot were performed in endothelial cells which were used to assess the angiogenic potential of MSCs-exo after inflammatory cytokine stimulation.RESULTS MSCs-exo were numerous,small,and regularly shaped in the VCAM-1 group.TNFαstimulated MSCs to secrete larger and irregular exosomes.IL6 led to a reduced quantity of MSCs-exo.Compared to the control group,the TNFαand IL6 groups had more downregulated differentially expressed miRNAs,particularly angiogenesis-related miRNAs.The angiogenic potential of MSCs-exo declined after IL6 stimulation.CONCLUSION TNFαand IL6 may influence the expression of miRNAs that down-regulate the PI3K-AKT,MAPK,and VEGF signaling pathways;particularly,IL6 significantly down-regulates the PI3K-AKT signaling pathway.Overall,inflammatory cytokines may lead to changes in exosomal miRNAs that abnormally impact cellular components,molecular function,and biological processes.
基金supported by the Industry Base Enhanced Project(TC160A310-10-01)Guangdong Sci&Tech Project(2013A090100002)Guangzhou Sci&Tech Project(2014Y2-00214)
文摘Fe-rich intermetallics, especially β-Fe phase, usually forming in the microstructure of cast aluminum alloys, are very detrimental to mechanical properties. In the present work, the effects of Fe content on phase transformation and microstructures were analyzed using a 3D X-ray microscope. Based on the highresolution 3D X-ray computed tomography, the 3D characteristics of Fe-rich intermetallics and micropores in the gravity-cast Al-6 Si alloys with different Fe contents were investigated. In addition, the effect of intermetallics on the microporosity was discussed. The results show that with increasing the Fe content from 0.10 wt.% to 0.60 wt.%, the volume fraction of Fe-rich intermetallics and the volume of the largest size Fe-rich intermetallic increased, and the 3D morphology of intermetallics changed from fine flake to network aggregation. As the Fe contents increased, the shrinkage pores were characterized, which were rather complex due to the micropores promoted by the intermetallics interactions.
基金Supported by the National Natural Science Foundation of China.
文摘We present quasi-simultaneous VLBI images of the GHz-Peaked-Spectrum radio source OQ 208 obtained with the Very Long Baseline Array at 1.4, 1.7, 2.3, 5.0, 8.4, 15.4 GHz and the European VLBI Network at 6.7 GHz. The low frequency (1.4, 1.7 and 2.3 GHz) observations reveal a weak and extended steep-spectrum component at about 30 mas away at position angle - 110°, which may be a remnant emission. The radio structure of OQ 208 consists of two mini-lobes at 5.0, 6.7, 8.4 and 15.4 GHz. Our spectral analysis further confirms that the southwest lobe undergoes free-free absorption and finds that the free-free absorption is stronger in the inner region. By fitting the 8.4 GHz images from 1994 to 2005, we obtain a separation speed of 0.0314-0.006 mas yr^-1 between the two mini-lobes. This indicates a jet proper motion of 0.1054-0.020 c and a kinematic age of 219±42 yr for the radio source.
基金the National Natu-ral Science Foundation of China(Nos.21572186,21622204 and 21772161)the Natural Science Foundation of Fujian Province of China(No.2019J02001)+2 种基金the President Research Funds from Xia-men University(No.20720180036)NFFTBS(No.J1310024)PCSIRT,and Science&Technology Cooperation Program of Xia-men(No.3502220183015).
文摘An efficient zinc-catalyzed oxidative cyclization of readily available indoly ynamides has been developed,enabling rapid and practical access to a diverse array of valuable medium-sized lactams in mostly good to excellent yields with wide substrate scope.In addition,such an asymmetric synthesis has also been explored by employing the chiral substrate.
基金We are grateful for financial support from the National Natural Science Foundation of China(Nos.21772161 and 21622204)the Natural Science Foundation of Fujian Province of China(No.2019J02001)+1 种基金the President Research Funds from Xiamen University(No.20720180036)NFFTBS(No.J1310024),PCSIRT,and Science&Technology Cooperation Program of Xiamen(No.3502Z20183015).
文摘Summary of main observation and conclusion An efficient copper-catalyzed carbocyclization of silyl enol ether tethered ynamides has been developed,allowing rapid and practical construction of diverse 2-azabicyclo[3.2.0]compounds in generally good to excellent yields with broad substrate scope under mild reaction conditions.Importantly,this protocol not only constitutes a rare example of non-noble metal-catalyzed alkyne carbocyclization,but also represents a rare cyclization on the B-position ofπu-tethered ynamides.The possibility of asymmetric carbocyclization via kinetic resolution also emerges.