The rise of artificial microstructures has made it possible to modulate propagation of various kinds of waves,such as light,sound and heat.Among them,the focusing effect is a modulation function of particular interest...The rise of artificial microstructures has made it possible to modulate propagation of various kinds of waves,such as light,sound and heat.Among them,the focusing effect is a modulation function of particular interest.We propose an atomic level triangular structure to realize the phonon focusing effect in single-layer graphene.In the positive incident direction,our phonon wave packet simulation results confirm that multiple features related to the phonon focusing effect can be controlled by adjusting the height of the triangular structure.More interestingly,a completed different focusing pattern and an enhanced energy transmission coefficient are found in the reverse incident direction.The detailed mode conversion physics is discussed based on the Fourier transform analysis on the spatial distribution of the phonon wave packet.Our study provides physical insights to achieving phonon focusing effect by designing atomic level microstructures.展开更多
Objective To prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacterpylori (H. pylori) B subunit (UreB) and to determine whether it could be used as an oral vaccine...Objective To prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacterpylori (H. pylori) B subunit (UreB) and to determine whether it could be used as an oral vaccine against H. pylori infection. Methods Using genomic DNA of H. pylori Sydney strain (SS1) as template, the H. pylori UreB gene fragment was amplified by PCR and subcloned into the expression vector pTC01. The recombinant plasmid pTC01-UreB was then transferred into LBS000 to obtain modified forms, and further conversed into the attenuated Salmonella typhimurium SL3261 to obtain recombinant SL3261/pCT01-UreB as an oral immunization reagent, which was then used to orally immunize Balb/c mice twice at a three-week interval. Twelve weeks later, anti-UreB IgA antibodies in intestinal fluid and IgG antibodies in sera were determined by ELISA. The relating data in control groups (including body weight, gastric inflammation, etc.) were also collected. Results The sequencing analysis showed that the UreB gene fragment amplified by PCR was consistent with the sequence of the H. pylori UreB gene. The restriction enzyme digestion revealed that the correct pTC01-UreB was obtained. SDS-PAGE and Western blot showed that a 61KD protein was expressed in SL3261/pTC01-UreB, which could be recognized by anti-H, pylori UreB antiserum and was absent in the control containing only Salmonella typhimurium SL3261 strain. The multiple oral immunization with SL3261/pTC01-UreB could significantly induce H. pylori specific mucosal IgA response as well as serum IgG responses. IFN-T and IL-10 levels were significantly increased in SL3261/pTC01-UreB group, and no obvious side effect and change in gastric inflammation were observed. Conclusion The attenuated vaccine of Salmonella typhimurium expressing H. pylori UreB can be used as an oral vaccine against H. pylori infection.展开更多
Exosomes secreted by tumor cells carry abundant molecular biomarkers that reflect the status of their originating cells.These tumor-derived exosomes(TDEs)have emerged as attractive diagnostic targets.However,the ident...Exosomes secreted by tumor cells carry abundant molecular biomarkers that reflect the status of their originating cells.These tumor-derived exosomes(TDEs)have emerged as attractive diagnostic targets.However,the identification and characterization of highly heterogeneous TDEs remain practically challenging.Here,we report a dual rolling circle amplification(DRCA)-assisted approach for the selective encapsulation of single TDEs for fluorescence microscopic and flow cytometric analysis.TDEs have been targeted by aptamers that recognized their surface tumor marker and exosomal marker CD63,following DRCA that produced entangling polymeric DNA chains,resulting in facile particle enlargement that allows single-particle fluorescence profiling of exosome heterogeneity.We have demonstrated the use of a dual-marker positive ratio for exosome differentiation and applied division and multiplication operations for normalized andmagnified marker heterogeneity analysis.We further applied this assay to distinguish lung adenocarcinoma and pulmonary nodule patients and found an accuracy of 90%.We anticipate promising transformations of this straightforward assay into clinically implantable diagnostic methods.展开更多
The reliability allowance of circuits tends to decrease with the increase of circuit integration and the application of new technology and materials, and the hardening strategy oriented toward gates is an effective te...The reliability allowance of circuits tends to decrease with the increase of circuit integration and the application of new technology and materials, and the hardening strategy oriented toward gates is an effective technology for improving the circuit reliability of the current situations. Therefore, a parallel-structured genetic algorithm (GA), PGA, is proposed in this paper to locate reliability-critical gates to successfully perform targeted hardening. Firstly, we design a binary coding method for reliability-critical gates and build an ordered initial population consisting of dominant individuals to improve the quality of the initial population. Secondly, we construct an embedded parallel operation loop for directional crossover and directional mutation to compensate for the deficiency of the poor local search of the GA. Thirdly, for combination with a diversity protection strategy for the population, we design an elitism retention based selection method to boost the convergence speed and avoid being trapped by a local optimum. Finally, we present an ordered identification method oriented toward reliability-critical gates using a scoring mechanism to retain the potential optimal solutions in each round to improve the robustness of the proposed locating method. The simulation results on benchmark circuits show that the proposed method PGA is an efficient locating method for reliability-critical gates in terms of accuracy and convergence speed.展开更多
The sources,transportation and depositional processes of lacustrine mudrock are still poorly understood.Existing studies have demonstrated the controlling effect of astronomical forcing on lacustrine mudrock depositio...The sources,transportation and depositional processes of lacustrine mudrock are still poorly understood.Existing studies have demonstrated the controlling effect of astronomical forcing on lacustrine mudrock deposition,but its depositional mechanism and evolution are still not systematically investigated.Most research related to astronomical forcing exclusively highlights the sedimentation of carbonate rocks in deep-water lacustrine setting,with insufficient attention paid to the thick organic-rich,deep-lake mudrock.With the increasing interest in exploration and development of shale oil and gas accumulations,it is urgent to deeply understand depositional rules of lacustrine mudrock.This study reviews sediment sources,depositional mechanism and evolution process of mudrock through expounding the correlations between the periodic changes of astronomical forces,the parameters of Earth orbital and mudrock compositions.By investigating the existing literature and using some actual data of Jiyang Depression,Bohai Bay Basin in East China,this study expounds on the influence of astronomical cycles on the deposition of lacustrine mudrock.Moreover,efforts are made to analyze the effects of various orbital parameters(e.g.,precession,obliquity,and eccentricity with the periods ranging from tens of thousands years to million years)on the deposition of mudrock from small-scale(decimeters to meters)to large-scale(10s to 100s meters).Further,it is feasible to apply the high-precision isochronous stratigraphic correlation into clarifying the distribution of favorable shale oil and gas reservoirs.To conclude,this study enunciates the sedimentation of mudrock from a new perspective(astronomical forcing)and provides a direction for the research on sedimentation of fine-grained sedimentary rocks.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12075168 and 11890703)the Science and Technology Commission of Shanghai Municipality(Grant No.21JC1405600)the Fundamental Research Funds for the Central Universities(Grant No.22120230212)。
文摘The rise of artificial microstructures has made it possible to modulate propagation of various kinds of waves,such as light,sound and heat.Among them,the focusing effect is a modulation function of particular interest.We propose an atomic level triangular structure to realize the phonon focusing effect in single-layer graphene.In the positive incident direction,our phonon wave packet simulation results confirm that multiple features related to the phonon focusing effect can be controlled by adjusting the height of the triangular structure.More interestingly,a completed different focusing pattern and an enhanced energy transmission coefficient are found in the reverse incident direction.The detailed mode conversion physics is discussed based on the Fourier transform analysis on the spatial distribution of the phonon wave packet.Our study provides physical insights to achieving phonon focusing effect by designing atomic level microstructures.
基金This work was supported by Chinese Postdoctoral Fund (Grant No. 2004035426).
文摘Objective To prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacterpylori (H. pylori) B subunit (UreB) and to determine whether it could be used as an oral vaccine against H. pylori infection. Methods Using genomic DNA of H. pylori Sydney strain (SS1) as template, the H. pylori UreB gene fragment was amplified by PCR and subcloned into the expression vector pTC01. The recombinant plasmid pTC01-UreB was then transferred into LBS000 to obtain modified forms, and further conversed into the attenuated Salmonella typhimurium SL3261 to obtain recombinant SL3261/pCT01-UreB as an oral immunization reagent, which was then used to orally immunize Balb/c mice twice at a three-week interval. Twelve weeks later, anti-UreB IgA antibodies in intestinal fluid and IgG antibodies in sera were determined by ELISA. The relating data in control groups (including body weight, gastric inflammation, etc.) were also collected. Results The sequencing analysis showed that the UreB gene fragment amplified by PCR was consistent with the sequence of the H. pylori UreB gene. The restriction enzyme digestion revealed that the correct pTC01-UreB was obtained. SDS-PAGE and Western blot showed that a 61KD protein was expressed in SL3261/pTC01-UreB, which could be recognized by anti-H, pylori UreB antiserum and was absent in the control containing only Salmonella typhimurium SL3261 strain. The multiple oral immunization with SL3261/pTC01-UreB could significantly induce H. pylori specific mucosal IgA response as well as serum IgG responses. IFN-T and IL-10 levels were significantly increased in SL3261/pTC01-UreB group, and no obvious side effect and change in gastric inflammation were observed. Conclusion The attenuated vaccine of Salmonella typhimurium expressing H. pylori UreB can be used as an oral vaccine against H. pylori infection.
基金supported by the National Key Research Program(grant no.2019YFA0905800)the NSFC Program(grant no.22090053)the Natural Science Foundation of Hunan Province(grant no.2021JJ40040).
文摘Exosomes secreted by tumor cells carry abundant molecular biomarkers that reflect the status of their originating cells.These tumor-derived exosomes(TDEs)have emerged as attractive diagnostic targets.However,the identification and characterization of highly heterogeneous TDEs remain practically challenging.Here,we report a dual rolling circle amplification(DRCA)-assisted approach for the selective encapsulation of single TDEs for fluorescence microscopic and flow cytometric analysis.TDEs have been targeted by aptamers that recognized their surface tumor marker and exosomal marker CD63,following DRCA that produced entangling polymeric DNA chains,resulting in facile particle enlargement that allows single-particle fluorescence profiling of exosome heterogeneity.We have demonstrated the use of a dual-marker positive ratio for exosome differentiation and applied division and multiplication operations for normalized andmagnified marker heterogeneity analysis.We further applied this assay to distinguish lung adenocarcinoma and pulmonary nodule patients and found an accuracy of 90%.We anticipate promising transformations of this straightforward assay into clinically implantable diagnostic methods.
基金supported by the National Natural Science Foundation of China under Grant Nos. 61972354,61502422,61432017, 61772199,61773348,and 61503338the Natural Science Foundation of Zhejiang Province of China under Grant Nos. LY18F020028+1 种基金LY18F030023,LY18F030084,and LY17F030016and the Innovative Experiment Project of Zhejiang University of Technology of China under Grant No. PX-68182112.
文摘The reliability allowance of circuits tends to decrease with the increase of circuit integration and the application of new technology and materials, and the hardening strategy oriented toward gates is an effective technology for improving the circuit reliability of the current situations. Therefore, a parallel-structured genetic algorithm (GA), PGA, is proposed in this paper to locate reliability-critical gates to successfully perform targeted hardening. Firstly, we design a binary coding method for reliability-critical gates and build an ordered initial population consisting of dominant individuals to improve the quality of the initial population. Secondly, we construct an embedded parallel operation loop for directional crossover and directional mutation to compensate for the deficiency of the poor local search of the GA. Thirdly, for combination with a diversity protection strategy for the population, we design an elitism retention based selection method to boost the convergence speed and avoid being trapped by a local optimum. Finally, we present an ordered identification method oriented toward reliability-critical gates using a scoring mechanism to retain the potential optimal solutions in each round to improve the robustness of the proposed locating method. The simulation results on benchmark circuits show that the proposed method PGA is an efficient locating method for reliability-critical gates in terms of accuracy and convergence speed.
基金supported by NSFC(Nos.21025521 and 21035001)National Key Basic Research Program(No. 2011CB911000)+1 种基金EU FP7-HEALTH-2010 Programme-GlycoHIT(No. 260600)CSIRT Program and NSF of Hunan Province(No.10JJ7002)
文摘Received 3 December 2012 Received in revised form 27 December 2012 Accepted 31 December 2012 Available online 4 February 2013
基金co-funded by the China National Key Research Project(Grant No.2017ZX05009-002)the National Natural Science Foundation of China(Grant Nos.41772090,41802130)the Foundation from Shandong Key Laboratory of Depositional Mineralization and Sedimentary Mineral,Shandong University of Science and Technology(Grant No.DMSM20190024)。
文摘The sources,transportation and depositional processes of lacustrine mudrock are still poorly understood.Existing studies have demonstrated the controlling effect of astronomical forcing on lacustrine mudrock deposition,but its depositional mechanism and evolution are still not systematically investigated.Most research related to astronomical forcing exclusively highlights the sedimentation of carbonate rocks in deep-water lacustrine setting,with insufficient attention paid to the thick organic-rich,deep-lake mudrock.With the increasing interest in exploration and development of shale oil and gas accumulations,it is urgent to deeply understand depositional rules of lacustrine mudrock.This study reviews sediment sources,depositional mechanism and evolution process of mudrock through expounding the correlations between the periodic changes of astronomical forces,the parameters of Earth orbital and mudrock compositions.By investigating the existing literature and using some actual data of Jiyang Depression,Bohai Bay Basin in East China,this study expounds on the influence of astronomical cycles on the deposition of lacustrine mudrock.Moreover,efforts are made to analyze the effects of various orbital parameters(e.g.,precession,obliquity,and eccentricity with the periods ranging from tens of thousands years to million years)on the deposition of mudrock from small-scale(decimeters to meters)to large-scale(10s to 100s meters).Further,it is feasible to apply the high-precision isochronous stratigraphic correlation into clarifying the distribution of favorable shale oil and gas reservoirs.To conclude,this study enunciates the sedimentation of mudrock from a new perspective(astronomical forcing)and provides a direction for the research on sedimentation of fine-grained sedimentary rocks.