From the practice of Chinese enterprises, the paper discusses three constraint conditions of China＇s internal controls including the system environmental constraint, cost constraint and organization constraint, and a...From the practice of Chinese enterprises, the paper discusses three constraint conditions of China＇s internal controls including the system environmental constraint, cost constraint and organization constraint, and advances the suggestions on the approaches to improve Chinese enterprises＇ internal controls level.展开更多
Objective The treatment planning system currently represents one of the basics of radiation therapy,because it is the only method to estimate patient dose delivery fast forward and accurately represent estimated tumor...Objective The treatment planning system currently represents one of the basics of radiation therapy,because it is the only method to estimate patient dose delivery fast forward and accurately represent estimated tumor location of the tumor with the possibility of estimating densities in the tissue surrounding the tumor to overcome dose calculation defects but radial estimated the patient.Despite the flaws associated with the systems and calculates the dose of your programs in all programs currently existing in the world.Than necessary,to the existence of a review of the accuracy of accounts and how to confirm the radiation dose to the patient programs.Methods A total of 35 cancer patients were considered for this study,with 245 field measurements made with low-and high-energy diode detectors for brain and prostate cases.The treatments for all patients were planned using Eclipse Treatment Planning System version 13.6.Results Of the 105 field measurements made for the prostate cancer patients,16 included discrepancies outside the ±5% action level.Of the 145 measurements taken of the brain cases,there were four outside the ±5% action level.The results indicated a higher degree of accuracy.The study revealed that,for the prostate measurements,the higher discrepancy in the doses for the particular fields(exceeding the action level) may have been due to the isocenter being very close to the jaws and multi-leaf collimator of the linear accelerator machine.As a result,scatter from the jaws and the multi-leaf collimator could have contributed to the high dose delivered to the diode;hence,a probable higher discrepancy of the dose in more brain cases due highest quality of VMAT technique and fixation system.Conclusion A greater percentage of the observed discrepancies were well within the set tolerance level.However,it is recommended that the positioning of the diode on the patient's skin and the angular sensitivity of the diodes be reconsidered.It is also recommended that a more accurate calculation of expected diode values be performed,especially for fields that pass through the table.These efforts would achieve action levels of ±5%.展开更多
Henri Poincare's intuitive concept of the linear continuum was described by his famous remark which was noted by Bertrand Russell, and in which the notion of 'intimate bond' first appeared. This semi-expos...Henri Poincare's intuitive concept of the linear continuum was described by his famous remark which was noted by Bertrand Russell, and in which the notion of 'intimate bond' first appeared. This semi-expository paper gives an exposition of Poincare's remark, and also aims at a formulation of the intimate bond with the aid of introducing a kind of 'leap structure' into Robinson's *R as a supplemental construction. As a result, we obtain a kind of hyperstandard model that may be called 'Poincare continuum'.展开更多
The Qinling Orogenic Belt is divided commonly by the Fengxian-Taibai strike-slip shear zone and the Huicheng Basin into the East and West Qinling mountains, which show significant geological differences after the Indo...The Qinling Orogenic Belt is divided commonly by the Fengxian-Taibai strike-slip shear zone and the Huicheng Basin into the East and West Qinling mountains, which show significant geological differences after the Indosinian orogeny. The Fengxian-Taibai fault zone and the Meso-Cenozoic Huicheng Basin, situated at the boundary of the East and West Qinling, provide a natural laboratory for tectonic analysis and sedimentological study of intracontinental tectonic evolution of the Qin- ling Orogenic Belt. In order to explain the dynamic development of the Huicheng Basin and elucidate its post-orogenic tecton- ic evolution at the junction of the East and West Qinling, we studied the geometry and kinematics of fault zones between the blocks of West Qinling, as well as the sedimentary fill history of the Huicheng Basin. First, we found that after the collisional orogeny in the Late Triassic, post-orogenic extensional collapse occurred in the Early and Middle Jurassic within the Qinling Orogenic Belt, resulting in a series of rift basins. Second, in the Late Jurassic and Early Cretaceous, a NE-SW compressive stress field caused large-scale sinistral strike-slip faults in the Qinling Orogenic Belt, causing intracontinental escape tectonics at the junction of the East and West Qinling, including eastward finite escape of the East Qinling micro-plate and southwest lateral escape of the Bikou Terrane. Meanwhile, the strike-slip-related Early Cretaceous sedimentary basin was formed with a fight-order echelon arrangement in sinistral shear zones along the southern margin of the Huicheng fault. Overall during the Mesozoic, the Huicheng Basin and surrounding areas experienced four tectonic evolutionary stages, including extensional rift basin development in the Early and Middle Jurassic, intense compressive uplift in the Late Jurassic, formation of a strike-slip extensional basin in the Early Cretaceous, and compressive uplift in the Late Cretaceous.展开更多
Inertial fusion energy （IFE） has been considered a promising, nearly inexhaustible source of sustainable carbon-free power for the world＇s energy future. It has long been recognized that the control of hydrodynamic...Inertial fusion energy （IFE） has been considered a promising, nearly inexhaustible source of sustainable carbon-free power for the world＇s energy future. It has long been recognized that the control of hydrodynamic instabilities is of critical importance for ignition and high-gain in the inertial-confinement fusion （ICF） hot-spot ignition scheme. In this mini-review, we summarize the progress of theoretical and simulation research of hydrodynamic instabilities in the ICF central hot-spot implosion in our group over the past decade. In order to obtain sufficient understanding of the growth of hydrodynamic instabilities in ICF, we first decompose the problem into different stages according to the implosion physics processes. The decomposed essential physics pro- cesses that are associated with ICF implosions, such as Rayleigh-Taylor instability （RTI）, Richtmyer-Meshkov instability （RMI）, Kelvin-Helmholtz instability （KHI）, convergent geometry effects, as well as perturbation feed-through are reviewed. Analyti- cal models in planar, cylindrical, and spherical geometries have been established to study different physical aspects, including density-gradient, interface-coupling, geometry, and convergent effects. The influence of ablation in the presence of preheating on the RTI has been extensively studied by numerical simulations. The KHI considering the ablation effect has been discussed in detail for the first time. A series of single-mode ablative RTI experiments has been performed on the Shenguang-II laser facility. The theoretical and simulation research provides us the physical insights of linear and weakly nonlinear growths, and nonlinear evolutions of the hydrodynamic instabilities in ICF implosions, which has directly supported the research of ICF ignition target design. The ICF hot-spot ignition implosion design that uses several controlling features, based on our current understanding of hydrodynamic instabilities, to address shell implosion stability, has been briefly described, several of which are novel.展开更多
Despite extensive studies on the mechanics of DNA under external constrains, such as tension, torsion, and bending, several important aspects have remained poorly understood. One biologically important example is the ...Despite extensive studies on the mechanics of DNA under external constrains, such as tension, torsion, and bending, several important aspects have remained poorly understood. One biologically important example is the mechanics of DNA under sharp bending conditions, which has been debated for a decade without thorough comprehension. The debate is about the interesting phenomenon raised from a series of different experiments: sharply bent DNA has a surprisingly high apparent bending flexibility that deviates from the canonical bending elasticity of DNA. This finding has motivated various theoretical models, which mainly incorporate the excitation of mechanical defects inside severely bent DNA molecules. Here, we review the recent progress on the understanding of the mechanics of sharply bent DNA and provide our view on this important question by interrogating the theoretical foundation of these experimental measurements.展开更多
Nanomicelles,self-assembling nanosized particles with a hydrophobic core and hydrophilic shell,are currently successfully used as carriers for targeted drug delivery systems via the enhanced permeability and retention...Nanomicelles,self-assembling nanosized particles with a hydrophobic core and hydrophilic shell,are currently successfully used as carriers for targeted drug delivery systems via the enhanced permeability and retention（EPR） effect at the tumor sites.In this study,a near-infrared fluorescent cyanine dye（Cy7-NHS） was conjugated to poly（ethylene glycol）-block-poly（ε-caprolactone）（NH 2-PEG-b-PCL）,and the resulting Cy7-PEG-PCL was further mixed with mPEG-b-PCL to form nanomicelles as carriers for paclitaxel（PTX） delivery.Our results showed that the selected mPEG 4000-b-PCL 2500 copolymers self-assembled to form stable micelles with an average size of 30 nm in diameter and a zeta potential of approximately-3 mV.The micelles also exhibited more than 95% encapsulation efficiency of PTX when the molar ratio between paclitaxel and copolymers was 1/4.In vitro cytotoxicity study showed that the PTX-loaded nanomicelles had a similar cell growth inhibition efficacy to that of Taxol against human breast cancer MCF-7 cells.In vivo imaging showed that the Cy7-labeled nanomicelles could be passively targeted to tumor sites effectively after intravenous injection via the tail vein.Also,a strong anti-tumor activity was observed in the nude mice xenografted MCF-7 breast tumor after treatment with PTX-loaded micelles,similar to that of Taxol.As a result,the micelle drug delivery system designed in this paper has great potential in targeted imaging of tumors and chemotherapy.展开更多
In this work,a focused ion beam(FIB)-scanning electron microscopy(SEM) dual beam system was successfully built by integrating a FIB column and a graphics generator onto a SEM.Real-time observation can be realized by S...In this work,a focused ion beam(FIB)-scanning electron microscopy(SEM) dual beam system was successfully built by integrating a FIB column and a graphics generator onto a SEM.Real-time observation can be realized by SEM during the process of FIB milling.All kinds of graphics at nanoscale regime,such as lines,characters,and pictures,were achieved under the control of graphics generator.Moreover,the FIB milling line width can be reduced nearly 27% by the introduction of simultaneous electron beam,and a line width as small as 10 nm was achieved.The numerical analysis indicates that the significant improvement on line width is induced by the Coulomb interaction between the electrons and ions.展开更多
Objective:Advanced glycation end-products (AGEs) exert inflammatory and oxidative stress insults to produce diabetic nephropathy mainly through the receptor for AGEs (RAGE).This study aimed to assess the effect of ato...Objective:Advanced glycation end-products (AGEs) exert inflammatory and oxidative stress insults to produce diabetic nephropathy mainly through the receptor for AGEs (RAGE).This study aimed to assess the effect of atorvastatin on diabetic nephropathy via soluble RAGE (sRAGE) and RAGE expressions in the rat kidney.Methods:Thirty-two male Sprague-Dawley rats were divided into four groups based on the presence or absence of streptozotocin-induced diabetes with or without atorvastatin treatment (10 mg/kg for 24 weeks).Serum sRAGE and glycated albumin (GA) levels were measured with enzyme-linked immunosorbent assay (ELISA) and improved bromocresol purple methods.Renal AGEs,RAGE,endogenous secretory RAGE (esRAGE),and sRAGE were determined with reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.Results:Mesangial expansion and microalbuminuria were aggravated in diabetic rats,and improved with atorvastatin treatment.Serum sRAGE levels were lower in diabetic than in normal rats.After atorvastatin treatment,serum and renal sRAGE levels were up-regulated,while renal RAGE expression was decreased in diabetic rats,associated with a reduction in accumulation of AGEs,though renal esRAGE mRNA expression was not significantly increased.Conclusions:Atorvastatin exerted a beneficial effect on diabetic nephropathy with reduced AGE accumulation,down-regulating RAGE expression and up-regulating sRAGE in the kidney.展开更多
In this paper, we introduce a multi-material arbitrary Lagrangian and Eulerian method for the hydrodynamic radiative multi-group diffusion model in 2D cylindrical coordinates. The basic idea in the construction of the...In this paper, we introduce a multi-material arbitrary Lagrangian and Eulerian method for the hydrodynamic radiative multi-group diffusion model in 2D cylindrical coordinates. The basic idea in the construction of the method is the following： In the Lagrangian step, a closure model of radiation-hydrodynamics is used to give the states of equations for materials in mixed cells. In the mesh rezoning step, we couple the rezoning principle with the Lagrangian interface tracking method and an Eulerian interface capturing scheme to compute interfaces sharply according to their deformation and to keep cells in good geometric quality. In the interface reconstruction step, a dual-material Moment-of-Fluid method is introduced to obtain the unique interface in mixed ceils. In the remapping step, a conservative remapping algorithm of conserved quantities is presented. A munber of numerical tests are carried out and the numerical results show that the new method can simulate instabilities in complex fluid field under large deformation, and are accurate and robust.展开更多
文摘From the practice of Chinese enterprises, the paper discusses three constraint conditions of China＇s internal controls including the system environmental constraint, cost constraint and organization constraint, and advances the suggestions on the approaches to improve Chinese enterprises＇ internal controls level.
文摘Objective The treatment planning system currently represents one of the basics of radiation therapy,because it is the only method to estimate patient dose delivery fast forward and accurately represent estimated tumor location of the tumor with the possibility of estimating densities in the tissue surrounding the tumor to overcome dose calculation defects but radial estimated the patient.Despite the flaws associated with the systems and calculates the dose of your programs in all programs currently existing in the world.Than necessary,to the existence of a review of the accuracy of accounts and how to confirm the radiation dose to the patient programs.Methods A total of 35 cancer patients were considered for this study,with 245 field measurements made with low-and high-energy diode detectors for brain and prostate cases.The treatments for all patients were planned using Eclipse Treatment Planning System version 13.6.Results Of the 105 field measurements made for the prostate cancer patients,16 included discrepancies outside the ±5% action level.Of the 145 measurements taken of the brain cases,there were four outside the ±5% action level.The results indicated a higher degree of accuracy.The study revealed that,for the prostate measurements,the higher discrepancy in the doses for the particular fields(exceeding the action level) may have been due to the isocenter being very close to the jaws and multi-leaf collimator of the linear accelerator machine.As a result,scatter from the jaws and the multi-leaf collimator could have contributed to the high dose delivered to the diode;hence,a probable higher discrepancy of the dose in more brain cases due highest quality of VMAT technique and fixation system.Conclusion A greater percentage of the observed discrepancies were well within the set tolerance level.However,it is recommended that the positioning of the diode on the patient's skin and the angular sensitivity of the diodes be reconsidered.It is also recommended that a more accurate calculation of expected diode values be performed,especially for fields that pass through the table.These efforts would achieve action levels of ±5%.
文摘Henri Poincare's intuitive concept of the linear continuum was described by his famous remark which was noted by Bertrand Russell, and in which the notion of 'intimate bond' first appeared. This semi-expository paper gives an exposition of Poincare's remark, and also aims at a formulation of the intimate bond with the aid of introducing a kind of 'leap structure' into Robinson's *R as a supplemental construction. As a result, we obtain a kind of hyperstandard model that may be called 'Poincare continuum'.
基金supported by National Natural Science Foundation of China(Grant Nos.40802051&41190074)MOST Special Fund from the State Key Laboratory of Continental DynamicsNorthwest University
文摘The Qinling Orogenic Belt is divided commonly by the Fengxian-Taibai strike-slip shear zone and the Huicheng Basin into the East and West Qinling mountains, which show significant geological differences after the Indosinian orogeny. The Fengxian-Taibai fault zone and the Meso-Cenozoic Huicheng Basin, situated at the boundary of the East and West Qinling, provide a natural laboratory for tectonic analysis and sedimentological study of intracontinental tectonic evolution of the Qin- ling Orogenic Belt. In order to explain the dynamic development of the Huicheng Basin and elucidate its post-orogenic tecton- ic evolution at the junction of the East and West Qinling, we studied the geometry and kinematics of fault zones between the blocks of West Qinling, as well as the sedimentary fill history of the Huicheng Basin. First, we found that after the collisional orogeny in the Late Triassic, post-orogenic extensional collapse occurred in the Early and Middle Jurassic within the Qinling Orogenic Belt, resulting in a series of rift basins. Second, in the Late Jurassic and Early Cretaceous, a NE-SW compressive stress field caused large-scale sinistral strike-slip faults in the Qinling Orogenic Belt, causing intracontinental escape tectonics at the junction of the East and West Qinling, including eastward finite escape of the East Qinling micro-plate and southwest lateral escape of the Bikou Terrane. Meanwhile, the strike-slip-related Early Cretaceous sedimentary basin was formed with a fight-order echelon arrangement in sinistral shear zones along the southern margin of the Huicheng fault. Overall during the Mesozoic, the Huicheng Basin and surrounding areas experienced four tectonic evolutionary stages, including extensional rift basin development in the Early and Middle Jurassic, intense compressive uplift in the Late Jurassic, formation of a strike-slip extensional basin in the Early Cretaceous, and compressive uplift in the Late Cretaceous.
基金supported by the National Natural Science Foundation of China(Grant Nos.11275031,11675026,11475032,11475034,11575033,and 11274026)the Foundation of President of Chinese Academy of Engineering Physics(Grant No.2014-1-040)the National Basic Research Program of China(Grant No.2013CB834100)
文摘Inertial fusion energy （IFE） has been considered a promising, nearly inexhaustible source of sustainable carbon-free power for the world＇s energy future. It has long been recognized that the control of hydrodynamic instabilities is of critical importance for ignition and high-gain in the inertial-confinement fusion （ICF） hot-spot ignition scheme. In this mini-review, we summarize the progress of theoretical and simulation research of hydrodynamic instabilities in the ICF central hot-spot implosion in our group over the past decade. In order to obtain sufficient understanding of the growth of hydrodynamic instabilities in ICF, we first decompose the problem into different stages according to the implosion physics processes. The decomposed essential physics pro- cesses that are associated with ICF implosions, such as Rayleigh-Taylor instability （RTI）, Richtmyer-Meshkov instability （RMI）, Kelvin-Helmholtz instability （KHI）, convergent geometry effects, as well as perturbation feed-through are reviewed. Analyti- cal models in planar, cylindrical, and spherical geometries have been established to study different physical aspects, including density-gradient, interface-coupling, geometry, and convergent effects. The influence of ablation in the presence of preheating on the RTI has been extensively studied by numerical simulations. The KHI considering the ablation effect has been discussed in detail for the first time. A series of single-mode ablative RTI experiments has been performed on the Shenguang-II laser facility. The theoretical and simulation research provides us the physical insights of linear and weakly nonlinear growths, and nonlinear evolutions of the hydrodynamic instabilities in ICF implosions, which has directly supported the research of ICF ignition target design. The ICF hot-spot ignition implosion design that uses several controlling features, based on our current understanding of hydrodynamic instabilities, to address shell implosion stability, has been briefly described, several of which are novel.
基金supported by the Mechanobiology Institute at National University of Singapore and Singapore Ministry of Education Academic Research Fund Tier 2 (Grant No. MOE2013-T2-1-154)
文摘Despite extensive studies on the mechanics of DNA under external constrains, such as tension, torsion, and bending, several important aspects have remained poorly understood. One biologically important example is the mechanics of DNA under sharp bending conditions, which has been debated for a decade without thorough comprehension. The debate is about the interesting phenomenon raised from a series of different experiments: sharply bent DNA has a surprisingly high apparent bending flexibility that deviates from the canonical bending elasticity of DNA. This finding has motivated various theoretical models, which mainly incorporate the excitation of mechanical defects inside severely bent DNA molecules. Here, we review the recent progress on the understanding of the mechanics of sharply bent DNA and provide our view on this important question by interrogating the theoretical foundation of these experimental measurements.
基金National Basic Research Program of China (973Program,Grant No. 2007CB935800 and 2009CB930300)Program forNew Drug R&D (Grant No. 2009ZX09310-001)+2 种基金NSFC projects(Grant No. 81072597)Beijing NSF project (Grant No. 7112089)Programs from Ministry of Education (Grant No. BMU20110268and BMU20110263)
文摘Nanomicelles,self-assembling nanosized particles with a hydrophobic core and hydrophilic shell,are currently successfully used as carriers for targeted drug delivery systems via the enhanced permeability and retention（EPR） effect at the tumor sites.In this study,a near-infrared fluorescent cyanine dye（Cy7-NHS） was conjugated to poly（ethylene glycol）-block-poly（ε-caprolactone）（NH 2-PEG-b-PCL）,and the resulting Cy7-PEG-PCL was further mixed with mPEG-b-PCL to form nanomicelles as carriers for paclitaxel（PTX） delivery.Our results showed that the selected mPEG 4000-b-PCL 2500 copolymers self-assembled to form stable micelles with an average size of 30 nm in diameter and a zeta potential of approximately-3 mV.The micelles also exhibited more than 95% encapsulation efficiency of PTX when the molar ratio between paclitaxel and copolymers was 1/4.In vitro cytotoxicity study showed that the PTX-loaded nanomicelles had a similar cell growth inhibition efficacy to that of Taxol against human breast cancer MCF-7 cells.In vivo imaging showed that the Cy7-labeled nanomicelles could be passively targeted to tumor sites effectively after intravenous injection via the tail vein.Also,a strong anti-tumor activity was observed in the nude mice xenografted MCF-7 breast tumor after treatment with PTX-loaded micelles,similar to that of Taxol.As a result,the micelle drug delivery system designed in this paper has great potential in targeted imaging of tumors and chemotherapy.
基金supported by the National Natural Science Foundation of China (Grant No. 50971011)Beijing Natural Science Foundation (Grant No. 1102025)+1 种基金Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20091102110038)the Fundamental Research Funds for the Central Universities (Grant No. 11174023)
文摘In this work,a focused ion beam(FIB)-scanning electron microscopy(SEM) dual beam system was successfully built by integrating a FIB column and a graphics generator onto a SEM.Real-time observation can be realized by SEM during the process of FIB milling.All kinds of graphics at nanoscale regime,such as lines,characters,and pictures,were achieved under the control of graphics generator.Moreover,the FIB milling line width can be reduced nearly 27% by the introduction of simultaneous electron beam,and a line width as small as 10 nm was achieved.The numerical analysis indicates that the significant improvement on line width is induced by the Coulomb interaction between the electrons and ions.
文摘Objective:Advanced glycation end-products (AGEs) exert inflammatory and oxidative stress insults to produce diabetic nephropathy mainly through the receptor for AGEs (RAGE).This study aimed to assess the effect of atorvastatin on diabetic nephropathy via soluble RAGE (sRAGE) and RAGE expressions in the rat kidney.Methods:Thirty-two male Sprague-Dawley rats were divided into four groups based on the presence or absence of streptozotocin-induced diabetes with or without atorvastatin treatment (10 mg/kg for 24 weeks).Serum sRAGE and glycated albumin (GA) levels were measured with enzyme-linked immunosorbent assay (ELISA) and improved bromocresol purple methods.Renal AGEs,RAGE,endogenous secretory RAGE (esRAGE),and sRAGE were determined with reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.Results:Mesangial expansion and microalbuminuria were aggravated in diabetic rats,and improved with atorvastatin treatment.Serum sRAGE levels were lower in diabetic than in normal rats.After atorvastatin treatment,serum and renal sRAGE levels were up-regulated,while renal RAGE expression was decreased in diabetic rats,associated with a reduction in accumulation of AGEs,though renal esRAGE mRNA expression was not significantly increased.Conclusions:Atorvastatin exerted a beneficial effect on diabetic nephropathy with reduced AGE accumulation,down-regulating RAGE expression and up-regulating sRAGE in the kidney.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11371065, 11126134, 11401033, 91130002 and 91330205)the China Academy of Engineering Physics Project (Grant Nos.2012A0202010 and 2015B0202035)+2 种基金the National High Technology Research and Development Program of China (Grant No. 2012AA01A303)the Foundation of Science and Technology Computation Physics Laboratorythe National Hi-Tech Inertial Confinement Fusion Committee of China
文摘In this paper, we introduce a multi-material arbitrary Lagrangian and Eulerian method for the hydrodynamic radiative multi-group diffusion model in 2D cylindrical coordinates. The basic idea in the construction of the method is the following： In the Lagrangian step, a closure model of radiation-hydrodynamics is used to give the states of equations for materials in mixed cells. In the mesh rezoning step, we couple the rezoning principle with the Lagrangian interface tracking method and an Eulerian interface capturing scheme to compute interfaces sharply according to their deformation and to keep cells in good geometric quality. In the interface reconstruction step, a dual-material Moment-of-Fluid method is introduced to obtain the unique interface in mixed ceils. In the remapping step, a conservative remapping algorithm of conserved quantities is presented. A munber of numerical tests are carried out and the numerical results show that the new method can simulate instabilities in complex fluid field under large deformation, and are accurate and robust.
