A full understanding of adaptive genetic variation at the genomic level will help address questions of how organisms adapt to diverse climates.Actinidia eriantha is a shade-tolerant species,widely distributed in the s...A full understanding of adaptive genetic variation at the genomic level will help address questions of how organisms adapt to diverse climates.Actinidia eriantha is a shade-tolerant species,widely distributed in the southern tropical region of China,occurring in spatially heterogeneous environments.In the present study we combined population genomic,epigenomic,and environmental association analyses to infer population genetic structure and positive selection across a climatic gradient,and to assess genomic offset to climatic change for A.eriantha.The population structure is strongly shaped by geography and influenced by restricted gene f low resulting from isolation by distance due to habitat fragmentation.In total,we identified 102 outlier loci and annotated 455 candidate genes associated with the genomic basis of climate adaptation,which were enriched in functional categories related to development processes and stress response;both temperature and precipitation are important factors driving adaptive variation.In addition to single-nucleotide polymorphisms(SNPs),a total of 27 single-methylation variants(SMVs)had significant correlation with at least one of four climatic variables and 16 SMVswere located in or adjacent to genes,several of whichwere predicted to be involved in plant response to abiotic or biotic stress.Gradient forest analysis indicated that the central/east populations were predicted to be at higher risk of future population maladaptation under climate change.Our results demonstrate that local climate factors impose strong selection pressures and lead to local adaptation.Such information adds to our understanding of adaptive mechanisms to variable climates revealed by both population genome and epigenome analysis.展开更多
The Abelmoschus esculentus(L.)Moench was previously reported to have various phytochemicals.Chemical fractionation yielded from the ethanolic extract of the A.esculentus ten compounds,including four alkaloids(4-6,8)an...The Abelmoschus esculentus(L.)Moench was previously reported to have various phytochemicals.Chemical fractionation yielded from the ethanolic extract of the A.esculentus ten compounds,including four alkaloids(4-6,8)and six phenolic acids(1-3,7,9-10).The structures of the compounds were elucidated through extensive spectra analyses and comparison of the experimental data with reported data.It is worth mentioning that compounds 1,2 and 5-10 were isolated from Abelmoschus esculentus(L.)for the first time.展开更多
Ten phenolic compounds(1a/1b,2–9)including a pair of enantiomers(1a/1b),along with eight analogues(2–9)were isolated from the fruit of Crataegus pinnatifida.Enantiomers 1a/1b were separated successfully by chiral ch...Ten phenolic compounds(1a/1b,2–9)including a pair of enantiomers(1a/1b),along with eight analogues(2–9)were isolated from the fruit of Crataegus pinnatifida.Enantiomers 1a/1b were separated successfully by chiral chromatographic column.Their structures were established by comprehensive spectroscopic analyses,and the absolute configurations of enantiomers were determined by comparison between the experimental and calculated electronic circular dichroism(ECD)spectra.In addition,all isolates were investigated for their neuroprotective effects against H2O2–induced oxidative stress in human neuroblastoma SH-SY5Y cells.It was found that enantiomers 1a and 1b displayed significant neuroprotective activities but no enantioselectivity.In addition,compounds 3–6 showed obvious neuroprotective effects at different concentrations,while compound 8 exhibited potential neuroprotective effect at higher concentration(50μmol/L).展开更多
The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER...The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER is a four-step,four-electron reaction,and its slow kinetics result in high overpotentials,posing a challenge.To address this issue,numerous strategies involving modified catalysts have been proposed and proven to be highly efficient.In these strategies,the introduction of strain has been widely reported because it is generally believed to effectively regulate the electronic structure of metal sites and alter the adsorption energy of catalyst surfaces with reaction intermediates.However,strain has many other effects that are not well known,making it an important yet unexplored area.Based on this,this review provides a detailed introduction to the various roles of strain in OER.To better explain these roles,the review also presents the definition of strain and elucidates the potential mechanisms of strain in OER based on the d-band center theory and adsorption volcano plot.Additionally,the review showcases various ways of introducing strain in OER through examples reported in the latest literature,aiming to provide a comprehensive perspective for the development of strain engineering.Finally,the review analyzes the appropriate proportion of strain introduction,compares compressive and tensile strain,and examines the impact of strain on stability.And the review offers prospects for future research directions in this emerging field.展开更多
Carbonate electrolytes are one of the most desirable electrolytes for high-energy lithium-sulfur batteries(LSBs)because of their successful implementation in commercial Li-ion batteries.The low-polysulfide-solubility ...Carbonate electrolytes are one of the most desirable electrolytes for high-energy lithium-sulfur batteries(LSBs)because of their successful implementation in commercial Li-ion batteries.The low-polysulfide-solubility feature of some carbonate solvents also makes them very promising for overcoming the shuttle effects of LSBs.However,regular sulfur electrodes experience undesired electrochemical mechanisms in carbonate electrolytes due to side reactions.In this study,we report a catalytic redox mechanism of sulfur in propylene carbonate(PC)electrolyte based on a compari-son study.The catalytic mechanism is characterized by the interactions between polysulfides and dual N/O functional groups on the host carbon,which largely prevents side reactions between polysulfides and the carbonate electrolyte.Such a mechanism coupled with the low-polysulfide-solubility feature leads to stable cycling of LSBs in PC electrolyte.Favorable dual N/O functional groups are identified via a density functional theory study.This work provides an alternative route for enabling LSBs in carbonate electrolytes.展开更多
目的:探讨闭角型青光眼患者红细胞免疫功能与血清促红细胞生成素(EPO)和血浆内皮素-1(ET-1)的相关性。方法:选取2017-06/10期间我院收治的闭角型青光眼患者30例(病例组)与眼部正常者30例(对照组)为研究对象。测定并比较两组受试者红细...目的:探讨闭角型青光眼患者红细胞免疫功能与血清促红细胞生成素(EPO)和血浆内皮素-1(ET-1)的相关性。方法:选取2017-06/10期间我院收治的闭角型青光眼患者30例(病例组)与眼部正常者30例(对照组)为研究对象。测定并比较两组受试者红细胞免疫功能、血清EPO和血浆ET-1浓度,分析之间的相关性。结果:病例组受试者红细胞C3b受体花环率明显低于对照组(10.81%±2.01%vs 18.06%±3.44%),红细胞免疫复合物花环率明显高于对照组(17.21±3.49%vs 11.74±2.14%),血清EPO浓度明显高于对照组(26.10±5.22 mU/mL vs 22.68±4.06mU/mL),血浆ET-1浓度明显高于对照组(70.85±7.16ng/L vs 58.43±5.09ng/L)。闭角型青光眼患者红细胞C3b受体花环率与血清EPO浓度呈显著正相关(r=0.271,P<0.05),与血浆ET-1浓度无明显相关性。结论:闭角型青光眼患者红细胞免疫功能与血清EPO浓度呈正相关。展开更多
Boscalid is a pesticide with the advantages of broad spectrum bactericidal activity,high efficiency,low toxicity,and no cross-resistance with other fungicides currently available on the market.Herein,we report the syn...Boscalid is a pesticide with the advantages of broad spectrum bactericidal activity,high efficiency,low toxicity,and no cross-resistance with other fungicides currently available on the market.Herein,we report the synthesis of 40-chloro-2-nitrobiphenyl,a key intermediate of Boscalid using a palladium-catalyzed Suzuki-Miyaura cross-coupling employing the 2-aryl-substituted indenyl phosphine ligand.40-Chloro-2-nitrobiphenyl was prepared in 94%yield on a 100 g scale.This method allows for the industrial production of alimide and active substances bearing a biphenyl moiety.展开更多
Due to requests on high rotary velocity of novel smart empennage-stable projectiles, the rolling characteristics under wide-angle oblique angles are studied. Since the wind tunnel tests performed verify numerical simu...Due to requests on high rotary velocity of novel smart empennage-stable projectiles, the rolling characteristics under wide-angle oblique angles are studied. Since the wind tunnel tests performed verify numerical simulation, so that the latter method can be applied to study the rolling characteristics widely combining theoretical models. In the theoretical part, the rolling dynamics equations are established considering the span, taper ratio and oblique angle of the empennages, and are further solved combing ballistic equations. For the simulation, the rolling moment coefficients under various rotary velocities are solved based on rotating coordinate system methods, so that the balance rotary velocity can be obtained using interpolation. The results indicate that shorter span, higher taper ratio and especially larger oblique angle can bring higher projectile rotary velocity;the balance rotary velocity is approximately linear to the oblique angle in a certain range.展开更多
Background: Little is known about the nature of metaistasis to small cervical lymph nodes(SCLNS) in the patients with nasopharyngeal carcinoma(NPC)examined by using 18-fluoro-2-deoxy-glucose(^(18)F-FDG) positron emiss...Background: Little is known about the nature of metaistasis to small cervical lymph nodes(SCLNS) in the patients with nasopharyngeal carcinoma(NPC)examined by using 18-fluoro-2-deoxy-glucose(^(18)F-FDG) positron emission tomography/computed tomography(PET/CT).The present study aimed to evaluate the diagnostic values of PET/CT in identifying metastasis in SCLNs in NPC patients.Methods: Magnetic resonance images(MRI) and PET/CT scans for 470 patients with newly diagnosed, non-distant metastatic NPC were analyzed. Metastatic rates of SCLNs were defined by the positive number of SCLNs on PET/CT scans and total number of SCLNs on MRI scans. Receiver operating characteristic curve was applied to compare PET/CT-determined stage with MRI-determined stage.Results: In total, 2082 SCLNs were identified, with 808(38.8%) ≥ 5 and < 6 mm in diameter(group A), 526(25.3%)≥ 6 and < 7 mm in diameter(group B),374(18.0%)≥ 7 and < 8 mm in diameter(group C), 237(11.4%) ≥8 and<9 mm in diameter(group D),and 137(6.5%) ≥ 9 and <10 mm in diameter(group E).The overall metastatic rates examined by using PET/CT for groups A, B,C,D, and E were 3.5%, 8.0%, 31.3%, 60.0%, and 83.9%, respectively(P< 0.001). In level IV/Vb, the metastatic rate for nodes ≥ 8 mm was 84.6%. PET/CT examination resulted in modification of N category and overall stage for 135(28.7%) and 46(9.8%) patients, respectively. The areas under curve of MRIdetermined and PET/CT-determined overall stage were 0.659 and 0.704 for predicting overall survival, 0.661 and 0.711 for predicting distant metastasis-free survival, and 0.636 and 0.663 for predicting disease-free survival.Conclusions: PET/CT was more effective than MRI in identifying metastatic SCLNs, and the radiologic diagnostic criteria for metastatic lymph nodes in level IV/Vb should be re-defined.展开更多
Background: The value of Epstein-Barr virus(EBV) DNA assay during posttreatment follow-up of the patients with nasopharyngeal carcinoma(NPC) presenting with different pretreatment plasma EBV DNA levels remains unclear...Background: The value of Epstein-Barr virus(EBV) DNA assay during posttreatment follow-up of the patients with nasopharyngeal carcinoma(NPC) presenting with different pretreatment plasma EBV DNA levels remains unclear. In the present study, we aimed to evaluate the prognostic value of plasma EBV DNA assay during posttreatment followup in the patients with NPC who have undergone intensity-modulated radiotherapy.Methods: The medical records of 385 NPC patients treated with intensity-modulated radiotherapy between November 2009 and February 2012 were reviewed. All patients underwent plasma EBV DNA assays before treatment, within3 months after treatment, and then every 3-12 months during posttreatment follow-up period. The recurrence rates for patients with different pretreatment and posttreatment follow-up plasma EBV DNA levels were analyzed.Results: Of the 385 patients, 267(69.4%) had detectable pretreatment plasma EBV DNA(> 0 copy/mL) and 93(24.2%) had detectable posttreatment EBV DNA during a median follow-up of 52.8 months(range 9.3-73.8 months).Detectable EBV DNA during posttreatment follow-up was found in 14.4%(17/118) and 28.5%(76/267) of patients with undetectable and detectable pretreatment EBV DNA, respectively, and was significantly associated with tumor recurrence in both patient groups. EBV DNA was detectable in 12.8%(40/313) of patients who remained disease-free,56.4%(22/39) of patients with locoregional recurrence alone, and 93.9%(31/33) of patients with distant metastasis as the first recurrence event(P < 0.001); 6.5%(19/292) of patients with undetectable EBV DNA and 57.0%(53/93) of patient with detectable EBV DNA during posttreatment follow-up experienced tumor recurrence. Compared with other cut-off values, the cut-off value of 0 copy/mL for EBV DNA during posttreatment follow-up had the highest area under the ROC curve(AUC) value(0.804,95% confidence interval 0.741-0.868) for predicting tumor recurrence(sensitivity, specificity, and accuracy: 73.6%, 87.2%, and 84.7%, respectively).Conclusion: Plasma EBV DNA level during posttreatment follow-up is a good marker for predicting distant metastasis but not locoregional recurrence in the patients with NPC irrespective of the pretreatment EBV DNA levels.展开更多
To improve the damage efficiency of compact terminal sensitive projectile with EFP warhead,it is vital to understand how the embedded structure(ES)affects the EFP forming performance.In this paper,the corresponding nu...To improve the damage efficiency of compact terminal sensitive projectile with EFP warhead,it is vital to understand how the embedded structure(ES)affects the EFP forming performance.In this paper,the corresponding numerical investigation is focused on,in which the fluid-structure interaction(FSI)method and the experimental verification are used.Based on the obtained quantitative relations between the forming performance and a(the ratio of height to maximum radius of ES),an optimal design is further provided.The results indicate that:when the embedded structural length and width range 0.1e0.3D and 0.1e0.2D(D:diameter of EFP warhead)at a fixed volume,respectively,EFP forming velocity nearly keeps as a constant,1760 m/s;the height of ES has a dramatical effect on the propagating range of detonation wave,resulting in significant influence on the aerodynamic shape and length-to-diameter ratio of EFP;under the given constraints,the EFP length-diameter ratio can reach the optimal value2.76,when the height of ES is 0.22D.展开更多
基金funded by the National Natural Science Foundation of China(grants 31770374 and 32070377)the Key Projects of the Joint Fund of the National Natural Science Foundation of China(grant U1802232).
文摘A full understanding of adaptive genetic variation at the genomic level will help address questions of how organisms adapt to diverse climates.Actinidia eriantha is a shade-tolerant species,widely distributed in the southern tropical region of China,occurring in spatially heterogeneous environments.In the present study we combined population genomic,epigenomic,and environmental association analyses to infer population genetic structure and positive selection across a climatic gradient,and to assess genomic offset to climatic change for A.eriantha.The population structure is strongly shaped by geography and influenced by restricted gene f low resulting from isolation by distance due to habitat fragmentation.In total,we identified 102 outlier loci and annotated 455 candidate genes associated with the genomic basis of climate adaptation,which were enriched in functional categories related to development processes and stress response;both temperature and precipitation are important factors driving adaptive variation.In addition to single-nucleotide polymorphisms(SNPs),a total of 27 single-methylation variants(SMVs)had significant correlation with at least one of four climatic variables and 16 SMVswere located in or adjacent to genes,several of whichwere predicted to be involved in plant response to abiotic or biotic stress.Gradient forest analysis indicated that the central/east populations were predicted to be at higher risk of future population maladaptation under climate change.Our results demonstrate that local climate factors impose strong selection pressures and lead to local adaptation.Such information adds to our understanding of adaptive mechanisms to variable climates revealed by both population genome and epigenome analysis.
文摘The Abelmoschus esculentus(L.)Moench was previously reported to have various phytochemicals.Chemical fractionation yielded from the ethanolic extract of the A.esculentus ten compounds,including four alkaloids(4-6,8)and six phenolic acids(1-3,7,9-10).The structures of the compounds were elucidated through extensive spectra analyses and comparison of the experimental data with reported data.It is worth mentioning that compounds 1,2 and 5-10 were isolated from Abelmoschus esculentus(L.)for the first time.
基金This work was supported by Career Development Support Plan for Young and Middle-aged Teachers in Shenyang Pharmaceutical University(ZQN2018006)the Project of Innovation Team Foundation(LT2015027).
文摘Ten phenolic compounds(1a/1b,2–9)including a pair of enantiomers(1a/1b),along with eight analogues(2–9)were isolated from the fruit of Crataegus pinnatifida.Enantiomers 1a/1b were separated successfully by chiral chromatographic column.Their structures were established by comprehensive spectroscopic analyses,and the absolute configurations of enantiomers were determined by comparison between the experimental and calculated electronic circular dichroism(ECD)spectra.In addition,all isolates were investigated for their neuroprotective effects against H2O2–induced oxidative stress in human neuroblastoma SH-SY5Y cells.It was found that enantiomers 1a and 1b displayed significant neuroprotective activities but no enantioselectivity.In addition,compounds 3–6 showed obvious neuroprotective effects at different concentrations,while compound 8 exhibited potential neuroprotective effect at higher concentration(50μmol/L).
基金financially supported by the National Natural Science Foundation of China(52071072)the Fundamental Research Funds for the Central Universities(2023GFZD03)+4 种基金the Natural Science Foundation-Steel,the Iron Foundation of Hebei Province(E2022501030)the Key Research and Development Plan of Qinhuangdao City(202302B013)the Liaoning Applied Basic Research Program(2023JH2/101300011)the Basic scientific research project of Liaoning Province Department of Education(LJKZZ20220024)the Shenyang Science and Technology Project(23-407-3-13)。
文摘The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER is a four-step,four-electron reaction,and its slow kinetics result in high overpotentials,posing a challenge.To address this issue,numerous strategies involving modified catalysts have been proposed and proven to be highly efficient.In these strategies,the introduction of strain has been widely reported because it is generally believed to effectively regulate the electronic structure of metal sites and alter the adsorption energy of catalyst surfaces with reaction intermediates.However,strain has many other effects that are not well known,making it an important yet unexplored area.Based on this,this review provides a detailed introduction to the various roles of strain in OER.To better explain these roles,the review also presents the definition of strain and elucidates the potential mechanisms of strain in OER based on the d-band center theory and adsorption volcano plot.Additionally,the review showcases various ways of introducing strain in OER through examples reported in the latest literature,aiming to provide a comprehensive perspective for the development of strain engineering.Finally,the review analyzes the appropriate proportion of strain introduction,compares compressive and tensile strain,and examines the impact of strain on stability.And the review offers prospects for future research directions in this emerging field.
基金supported by the National Natural Science Foundation of China (Nos. 52074069, 52174314)the Natural Science Foundation of Hebei Province,China (Nos. E2020501022, E2022501030)+2 种基金the Fundamental Research Funds for the Central Universities,China (Nos. N2223027, N2223009)the Science and Technology Project of Hebei Education Department,China (Nos. ZD2021331)Performance Subsidy Fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province,China (No. 22567627H)。
文摘Carbonate electrolytes are one of the most desirable electrolytes for high-energy lithium-sulfur batteries(LSBs)because of their successful implementation in commercial Li-ion batteries.The low-polysulfide-solubility feature of some carbonate solvents also makes them very promising for overcoming the shuttle effects of LSBs.However,regular sulfur electrodes experience undesired electrochemical mechanisms in carbonate electrolytes due to side reactions.In this study,we report a catalytic redox mechanism of sulfur in propylene carbonate(PC)electrolyte based on a compari-son study.The catalytic mechanism is characterized by the interactions between polysulfides and dual N/O functional groups on the host carbon,which largely prevents side reactions between polysulfides and the carbonate electrolyte.Such a mechanism coupled with the low-polysulfide-solubility feature leads to stable cycling of LSBs in PC electrolyte.Favorable dual N/O functional groups are identified via a density functional theory study.This work provides an alternative route for enabling LSBs in carbonate electrolytes.
文摘目的:探讨闭角型青光眼患者红细胞免疫功能与血清促红细胞生成素(EPO)和血浆内皮素-1(ET-1)的相关性。方法:选取2017-06/10期间我院收治的闭角型青光眼患者30例(病例组)与眼部正常者30例(对照组)为研究对象。测定并比较两组受试者红细胞免疫功能、血清EPO和血浆ET-1浓度,分析之间的相关性。结果:病例组受试者红细胞C3b受体花环率明显低于对照组(10.81%±2.01%vs 18.06%±3.44%),红细胞免疫复合物花环率明显高于对照组(17.21±3.49%vs 11.74±2.14%),血清EPO浓度明显高于对照组(26.10±5.22 mU/mL vs 22.68±4.06mU/mL),血浆ET-1浓度明显高于对照组(70.85±7.16ng/L vs 58.43±5.09ng/L)。闭角型青光眼患者红细胞C3b受体花环率与血清EPO浓度呈显著正相关(r=0.271,P<0.05),与血浆ET-1浓度无明显相关性。结论:闭角型青光眼患者红细胞免疫功能与血清EPO浓度呈正相关。
基金the National Natural Science Foundation of China(nos.22371084,21072071,21472060 and 21772058)the 111 Project B17019,self-determined research funds of CCNU from the colleges'basic research and operation of MOE(No.CCNU17CG0011,CCNU17KYZHSY07,and CCNU18KYZHSY06)for financial support.
文摘Boscalid is a pesticide with the advantages of broad spectrum bactericidal activity,high efficiency,low toxicity,and no cross-resistance with other fungicides currently available on the market.Herein,we report the synthesis of 40-chloro-2-nitrobiphenyl,a key intermediate of Boscalid using a palladium-catalyzed Suzuki-Miyaura cross-coupling employing the 2-aryl-substituted indenyl phosphine ligand.40-Chloro-2-nitrobiphenyl was prepared in 94%yield on a 100 g scale.This method allows for the industrial production of alimide and active substances bearing a biphenyl moiety.
文摘Due to requests on high rotary velocity of novel smart empennage-stable projectiles, the rolling characteristics under wide-angle oblique angles are studied. Since the wind tunnel tests performed verify numerical simulation, so that the latter method can be applied to study the rolling characteristics widely combining theoretical models. In the theoretical part, the rolling dynamics equations are established considering the span, taper ratio and oblique angle of the empennages, and are further solved combing ballistic equations. For the simulation, the rolling moment coefficients under various rotary velocities are solved based on rotating coordinate system methods, so that the balance rotary velocity can be obtained using interpolation. The results indicate that shorter span, higher taper ratio and especially larger oblique angle can bring higher projectile rotary velocity;the balance rotary velocity is approximately linear to the oblique angle in a certain range.
基金supported by grants from the Science and Technology Project of Guangzhou City,China(No.14570006)the Planned Science and Technology Project of Guangdong Province,China(No.2013B020400004)
文摘Background: Little is known about the nature of metaistasis to small cervical lymph nodes(SCLNS) in the patients with nasopharyngeal carcinoma(NPC)examined by using 18-fluoro-2-deoxy-glucose(^(18)F-FDG) positron emission tomography/computed tomography(PET/CT).The present study aimed to evaluate the diagnostic values of PET/CT in identifying metastasis in SCLNs in NPC patients.Methods: Magnetic resonance images(MRI) and PET/CT scans for 470 patients with newly diagnosed, non-distant metastatic NPC were analyzed. Metastatic rates of SCLNs were defined by the positive number of SCLNs on PET/CT scans and total number of SCLNs on MRI scans. Receiver operating characteristic curve was applied to compare PET/CT-determined stage with MRI-determined stage.Results: In total, 2082 SCLNs were identified, with 808(38.8%) ≥ 5 and < 6 mm in diameter(group A), 526(25.3%)≥ 6 and < 7 mm in diameter(group B),374(18.0%)≥ 7 and < 8 mm in diameter(group C), 237(11.4%) ≥8 and<9 mm in diameter(group D),and 137(6.5%) ≥ 9 and <10 mm in diameter(group E).The overall metastatic rates examined by using PET/CT for groups A, B,C,D, and E were 3.5%, 8.0%, 31.3%, 60.0%, and 83.9%, respectively(P< 0.001). In level IV/Vb, the metastatic rate for nodes ≥ 8 mm was 84.6%. PET/CT examination resulted in modification of N category and overall stage for 135(28.7%) and 46(9.8%) patients, respectively. The areas under curve of MRIdetermined and PET/CT-determined overall stage were 0.659 and 0.704 for predicting overall survival, 0.661 and 0.711 for predicting distant metastasis-free survival, and 0.636 and 0.663 for predicting disease-free survival.Conclusions: PET/CT was more effective than MRI in identifying metastatic SCLNs, and the radiologic diagnostic criteria for metastatic lymph nodes in level IV/Vb should be re-defined.
基金supported by grants from the Natural Science Foundation of Guangdong Province,China(No.2015A030310033)the Health&Medical Collaborative Innovation Project of Guangzhou City,China(No.201400000001)the Key Laboratory Construction Project of Guangzhou City(No.121800085)
文摘Background: The value of Epstein-Barr virus(EBV) DNA assay during posttreatment follow-up of the patients with nasopharyngeal carcinoma(NPC) presenting with different pretreatment plasma EBV DNA levels remains unclear. In the present study, we aimed to evaluate the prognostic value of plasma EBV DNA assay during posttreatment followup in the patients with NPC who have undergone intensity-modulated radiotherapy.Methods: The medical records of 385 NPC patients treated with intensity-modulated radiotherapy between November 2009 and February 2012 were reviewed. All patients underwent plasma EBV DNA assays before treatment, within3 months after treatment, and then every 3-12 months during posttreatment follow-up period. The recurrence rates for patients with different pretreatment and posttreatment follow-up plasma EBV DNA levels were analyzed.Results: Of the 385 patients, 267(69.4%) had detectable pretreatment plasma EBV DNA(> 0 copy/mL) and 93(24.2%) had detectable posttreatment EBV DNA during a median follow-up of 52.8 months(range 9.3-73.8 months).Detectable EBV DNA during posttreatment follow-up was found in 14.4%(17/118) and 28.5%(76/267) of patients with undetectable and detectable pretreatment EBV DNA, respectively, and was significantly associated with tumor recurrence in both patient groups. EBV DNA was detectable in 12.8%(40/313) of patients who remained disease-free,56.4%(22/39) of patients with locoregional recurrence alone, and 93.9%(31/33) of patients with distant metastasis as the first recurrence event(P < 0.001); 6.5%(19/292) of patients with undetectable EBV DNA and 57.0%(53/93) of patient with detectable EBV DNA during posttreatment follow-up experienced tumor recurrence. Compared with other cut-off values, the cut-off value of 0 copy/mL for EBV DNA during posttreatment follow-up had the highest area under the ROC curve(AUC) value(0.804,95% confidence interval 0.741-0.868) for predicting tumor recurrence(sensitivity, specificity, and accuracy: 73.6%, 87.2%, and 84.7%, respectively).Conclusion: Plasma EBV DNA level during posttreatment follow-up is a good marker for predicting distant metastasis but not locoregional recurrence in the patients with NPC irrespective of the pretreatment EBV DNA levels.
基金funded by the National Natural Science Foundation of China under No. 11102088Fundamental Research Funds for the Central Universities under No. 30915118821funded by the Specialized Research Fund for the Doctoral Program of Higher Education of China under No. 20133219110019
文摘To improve the damage efficiency of compact terminal sensitive projectile with EFP warhead,it is vital to understand how the embedded structure(ES)affects the EFP forming performance.In this paper,the corresponding numerical investigation is focused on,in which the fluid-structure interaction(FSI)method and the experimental verification are used.Based on the obtained quantitative relations between the forming performance and a(the ratio of height to maximum radius of ES),an optimal design is further provided.The results indicate that:when the embedded structural length and width range 0.1e0.3D and 0.1e0.2D(D:diameter of EFP warhead)at a fixed volume,respectively,EFP forming velocity nearly keeps as a constant,1760 m/s;the height of ES has a dramatical effect on the propagating range of detonation wave,resulting in significant influence on the aerodynamic shape and length-to-diameter ratio of EFP;under the given constraints,the EFP length-diameter ratio can reach the optimal value2.76,when the height of ES is 0.22D.
