<div style="text-align:justify;"> <span style="font-family:Verdana;">The purpose of this study was to evaluate a planning strategy based on Acuros with density override in comparison wi...<div style="text-align:justify;"> <span style="font-family:Verdana;">The purpose of this study was to evaluate a planning strategy based on Acuros with density override in comparison with AAA without and with the override. Ten lung-tumor patients were selected with each PTV size around 2 - 4 cm and were imaged using slow scan, followed by four-dimensional (4D) imag</span><span style="font-family:Verdana;">ing limited to the target. On each phase-specific image, gross tumor </span><span style="font-family:Verdana;">volume (GTV) was contoured. Summed over all phases, an integrated GTV (iGTV) was generated and copied to the slow scan. A treatment plan was created using a dynamic-conformal-arc technique with AAA to prescribe 60 Gy to 95% of PTV (iGTV + 0.5 cm). Each AAA-based plan was regenerated by overriding the density of the setup margin of PTV by GTV density (modeling tumor-position uncertainty). It was also regenerated with Acuros and the override. The three plans were validated in 4D dose to PTV, after similarly overriding PTV density (phase-specific), accurately calculating with Acuros, and summing the phase-specific plans through organ/dose registration. The Acuros-based plan with the override, the AAA-based plan, and the AAA-based plan with the override provided 4D PTV doses of 63.9, 67.9, and 62 Gy at D95%, respectively, averaged over all patients. The override with Acuros and AAA produced lesser 4D doses, closer to the associated 3D doses, respectively, than that without the override, with better conformity and inhomogeneity. With the override in common, Acuros provided a greater dose to PTV than that by AAA. The Acuros with the override, which was more accurate than the AAA without the override, is clinically recommended.</span> </div>展开更多
Utilizing primary documents available at the George Bush Presidential Library, this study evaluates the veto record of President Bush using a case study as well as quantitative methods. The case study reviews the back...Utilizing primary documents available at the George Bush Presidential Library, this study evaluates the veto record of President Bush using a case study as well as quantitative methods. The case study reviews the background and fate of the only veto overridden during his term in office. It finds that the Bush White House had tried on several previous occasions to scrap the legislation, only to have it be reintroduced in each succeeding Congress. By 1992, when George Bush was running for reelection and in trouble politically, his team was unable to stave off defeat. The article likewise assesses the success of the Bush administration in its employment of the veto and compares the veto record of President Bush to previous and subsequent chief executives.展开更多
To improve the oil recovery and economic efficiency in heavy oil reservoirs in late steam flooding,taking J6 Block of Xinjiang Oilfield as the research object,3D physical modeling experiments of steam flooding,CO2-foa...To improve the oil recovery and economic efficiency in heavy oil reservoirs in late steam flooding,taking J6 Block of Xinjiang Oilfield as the research object,3D physical modeling experiments of steam flooding,CO2-foam assisted steam flooding,and CO2 assisted steam flooding under different perforation conditions are conducted,and CO2-assisted steam flooding is proposed for reservoirs in the late stage of steam flooding.The experimental results show that after adjusting the perforation in late steam flooding,the CO2 assisted steam flooding formed a lateral expansion of the steam chamber in the middle and lower parts of the injection well and a development mode for the production of overriding gravity oil drainage in the top chamber of the production well;high temperature water,oil,and CO2 formed stable low-viscosity quasi-single-phase emulsified fluid;and CO2 acted as a thermal insulation in the steam chamber at the top,reduced the steam partial pressure inside the steam chamber,and effectively improved the heat efficiency of injected steam.Based on the three-dimensional physical experiments and the developed situation of the J6 block in Xinjiang Oilfield,the CO2 assisted steam flooding for the J6 block was designed.The application showed that the CO2 assisted steam flooding made the oil vapor ratio increase from 0.12 to 0.16 by 34.0%,the oil recovery increase from 16.1%to 21.5%,and the final oil recovery goes up to 66.5%compared to steam flooding after perforation adjustment.展开更多
Sinus venosus defects include two varieties,superior and inferior sinus venosus defects.The superior sinus venosus defect is characterized by abnormal communication between two closely related venoatrial structures:1)...Sinus venosus defects include two varieties,superior and inferior sinus venosus defects.The superior sinus venosus defect is characterized by abnormal communication between two closely related venoatrial structures:1)the normally positioned superior vena cava-right atrium complex and 2)the right pulmonary vein-left atrium complex that is displaced leftward,forward and upward.Inferior sinus venosus defects primarily involve the inferior vena cava-right atrial junction while the right pulmonary vein-left atrial junction can also be affected.Because of the rarity and wide variation of the defects,the morphological characterization of sinus venosus defects is inconsistent among investigators and often inaccurate.Modern imaging technologies with high spatial and temporal resolutions have allowed accurate and detailed assessment of the pathological anatomy in larger numbers of cases.In this pictorial essay,we revisit the established and controversial features of the sinus venous defects using twodimensional(2D)and three-dimensional(3D)images obtained by magnetic resonance(MR)or computed tomography(CT)with brief discussion on imaging and treatment strategies.展开更多
Objective:Overriding/straddling of an atrioventricular valve is a consequence of atrial-ventricular septal malalignment.We sought to characterize the malalignment by analogizing it to a flap-door and using structured ...Objective:Overriding/straddling of an atrioventricular valve is a consequence of atrial-ventricular septal malalignment.We sought to characterize the malalignment by analogizing it to a flap-door and using structured approach.Methods:The echocardiograms and magnetic resonance images of 35 patients with overriding/straddling tricuspid or mitral valve were evaluated to assess the following modifiers;the malaligned part of the septum,the reference structure,and the mechanism,direction and severity of malalignment.Results:The pathology included classic overriding tricuspid valve in 15,classic overriding mitral valve in 12,and overriding tricuspid valve with left juxtaposition of atrial appendages in 8.In classic overriding tricuspid valve,the ventricular septum was hinged to the anterior interventricular groove and its insertion to the posterior interventricular groove was displaced toward the right ventricle.The VSD primarily involved the inlet but also extended toward the anterior interventricular groove.In classic overriding mitral valve,the ventricular septum was hinged to the posterior interventricular groove and crux cordis.Its insertion to the anterior interventricular groove was displaced toward the left ventricle.The VSD primarily involved the anterior part but also extended toward the inlet.Overriding tricuspid valve with left juxtaposition of atrial appendages had a mild degree of malalignment with displacement/rotation of the atrioventricular junction.Evenly spaced short-axis images were most helpful in characterizing the pathology.Conclusions:Overriding/straddling atrioventricular valves can be easily understood by analogizing the atrial-ventricular septal malalignment to a flap-door and describing the pathology in a structured manner.Contrary to what has previously been known,the VSD is not limited to the inlet or outlet part of the ventricular septum.展开更多
The seismicity along the Himalayan arc varies significantly with some well defined patterns of segmentations.We show that the earthquakes along the Himalayan Seismic Belt(HSB)are influenced by the structural heterogen...The seismicity along the Himalayan arc varies significantly with some well defined patterns of segmentations.We show that the earthquakes along the Himalayan Seismic Belt(HSB)are influenced by the structural heterogeneities existing in the underthrusting Indian plate as well as by the presence of various north-south trending active rifts in the overriding wedge of the Himalaya.Model calculations of stress distribution show that stress change due to strain accumulation is more on moderately steeper fault,simulating the midcrustal ramp under the southern Higher Himalaya,than on the sub-horizontal thrust.Thus it is surmised that the presence of the ramp which connects the shallow section of seismically active detachment to the aseismically slipping deeper section of the detachment,causes high seismicity in the HSB region.It implies that the seismicity variation along the HSB may also be linked to the presence or absence of the ramp.Further,subsurface ridges on the down-going Indian plate probably control the rupture extent of the great Himalayan earthquakes.Over these ridges the seismicity of the HSB is generally low and it may imply that ramp may be absent in those regions.Finally,we show that the approximately north-south extending active rifts of the Tibetan and Higher Himalaya,cause stress shadow near their southern extent in the HSB which inhibit the occurrence of small and moderate magnitude thrust earthquakes.展开更多
CNC machining plays an important role in mechanical manufacturing.A key issue is to improve the machining feedrate while keeping the machining precision and satisfying the acceleration constraints of the CNC machine.F...CNC machining plays an important role in mechanical manufacturing.A key issue is to improve the machining feedrate while keeping the machining precision and satisfying the acceleration constraints of the CNC machine.For the consecutive micro-line segments interpolation,the velocities at the junction of two segments are the bottlenecks for the machining efficiency.This paper proposes a multi-period turning method to improve the feedrate at the junctions using the linear acceleration and deceleration mode,which utilizes the maximal acceleration capabilities of the NC machine while satisfying the machining precision.A new and more efficient look-ahead method and a feedrate override method are also proposed to boast the global machining speed.The proposed algorithm has been implemented on Blue Sky NC System,and experimented in real material manufacturing.Compared with several existing algorithms,the current algorithm can improve the manufacturing time ranging from 50% to 180%,depending on the machining parameters,and also results in better machining quality.In addition,the algorithm also satisfies the need of real-time interpolation.展开更多
Twenty years ago,far-sighted leaders of China and the Association of Southeast Asian Nations(ASEAN)launched a dialogue that deep-ened mutual understanding and trust,and helped forge close cooperation between the two s...Twenty years ago,far-sighted leaders of China and the Association of Southeast Asian Nations(ASEAN)launched a dialogue that deep-ened mutual understanding and trust,and helped forge close cooperation between the two sides.Since then,China and ASEAN have bolstered part-nerships展开更多
Tetralogy of Fallot(TOF)is the most prevalent form of cyanotic congenital heart disease(CHD),affecting approximately 3%-5%of infants with CHD,which corresponds to one in 3600 live births(0.28‰).Both males and females...Tetralogy of Fallot(TOF)is the most prevalent form of cyanotic congenital heart disease(CHD),affecting approximately 3%-5%of infants with CHD,which corresponds to one in 3600 live births(0.28‰).Both males and females are equally affected(Gibbs 2003).The first precise anatomical description of TOF was provided by William Hunter in 1784,although the term“TOF”was coined later by Maude Abbott in 1924 to describe a tetrad consisting of(i)a ventricular septal defect,(ii)an overriding aorta,(iii)right ventricular outflow obstruction,and(iv)right ventricular hypertrophy(Apitz et al.2009).Due to surgical interventions during infancy,85%-90%of TOF patients survive beyond 30 years of age(Ferencz et al.1985;Starr 2010),marking a significant achievement in modern medicine.However,the cause of TOF,like many other forms of congenital heart disease(CHD),remains largely unknown.However,a high recurrence risk of approximately 3%in siblings without other affected first-degree relatives suggests a significant genetic component.In this regard,an original study led by Dr.Guoying Huang and Dr.Wei Sheng and their colleagues provided important evidence linking MST1R as a candidate genetically associated gene to TOF.展开更多
文摘<div style="text-align:justify;"> <span style="font-family:Verdana;">The purpose of this study was to evaluate a planning strategy based on Acuros with density override in comparison with AAA without and with the override. Ten lung-tumor patients were selected with each PTV size around 2 - 4 cm and were imaged using slow scan, followed by four-dimensional (4D) imag</span><span style="font-family:Verdana;">ing limited to the target. On each phase-specific image, gross tumor </span><span style="font-family:Verdana;">volume (GTV) was contoured. Summed over all phases, an integrated GTV (iGTV) was generated and copied to the slow scan. A treatment plan was created using a dynamic-conformal-arc technique with AAA to prescribe 60 Gy to 95% of PTV (iGTV + 0.5 cm). Each AAA-based plan was regenerated by overriding the density of the setup margin of PTV by GTV density (modeling tumor-position uncertainty). It was also regenerated with Acuros and the override. The three plans were validated in 4D dose to PTV, after similarly overriding PTV density (phase-specific), accurately calculating with Acuros, and summing the phase-specific plans through organ/dose registration. The Acuros-based plan with the override, the AAA-based plan, and the AAA-based plan with the override provided 4D PTV doses of 63.9, 67.9, and 62 Gy at D95%, respectively, averaged over all patients. The override with Acuros and AAA produced lesser 4D doses, closer to the associated 3D doses, respectively, than that without the override, with better conformity and inhomogeneity. With the override in common, Acuros provided a greater dose to PTV than that by AAA. The Acuros with the override, which was more accurate than the AAA without the override, is clinically recommended.</span> </div>
文摘Utilizing primary documents available at the George Bush Presidential Library, this study evaluates the veto record of President Bush using a case study as well as quantitative methods. The case study reviews the background and fate of the only veto overridden during his term in office. It finds that the Bush White House had tried on several previous occasions to scrap the legislation, only to have it be reintroduced in each succeeding Congress. By 1992, when George Bush was running for reelection and in trouble politically, his team was unable to stave off defeat. The article likewise assesses the success of the Bush administration in its employment of the veto and compares the veto record of President Bush to previous and subsequent chief executives.
基金Supported by the China National Science and Technology Major Project(2016ZX05012-002).
文摘To improve the oil recovery and economic efficiency in heavy oil reservoirs in late steam flooding,taking J6 Block of Xinjiang Oilfield as the research object,3D physical modeling experiments of steam flooding,CO2-foam assisted steam flooding,and CO2 assisted steam flooding under different perforation conditions are conducted,and CO2-assisted steam flooding is proposed for reservoirs in the late stage of steam flooding.The experimental results show that after adjusting the perforation in late steam flooding,the CO2 assisted steam flooding formed a lateral expansion of the steam chamber in the middle and lower parts of the injection well and a development mode for the production of overriding gravity oil drainage in the top chamber of the production well;high temperature water,oil,and CO2 formed stable low-viscosity quasi-single-phase emulsified fluid;and CO2 acted as a thermal insulation in the steam chamber at the top,reduced the steam partial pressure inside the steam chamber,and effectively improved the heat efficiency of injected steam.Based on the three-dimensional physical experiments and the developed situation of the J6 block in Xinjiang Oilfield,the CO2 assisted steam flooding for the J6 block was designed.The application showed that the CO2 assisted steam flooding made the oil vapor ratio increase from 0.12 to 0.16 by 34.0%,the oil recovery increase from 16.1%to 21.5%,and the final oil recovery goes up to 66.5%compared to steam flooding after perforation adjustment.
文摘Sinus venosus defects include two varieties,superior and inferior sinus venosus defects.The superior sinus venosus defect is characterized by abnormal communication between two closely related venoatrial structures:1)the normally positioned superior vena cava-right atrium complex and 2)the right pulmonary vein-left atrium complex that is displaced leftward,forward and upward.Inferior sinus venosus defects primarily involve the inferior vena cava-right atrial junction while the right pulmonary vein-left atrial junction can also be affected.Because of the rarity and wide variation of the defects,the morphological characterization of sinus venosus defects is inconsistent among investigators and often inaccurate.Modern imaging technologies with high spatial and temporal resolutions have allowed accurate and detailed assessment of the pathological anatomy in larger numbers of cases.In this pictorial essay,we revisit the established and controversial features of the sinus venous defects using twodimensional(2D)and three-dimensional(3D)images obtained by magnetic resonance(MR)or computed tomography(CT)with brief discussion on imaging and treatment strategies.
文摘Objective:Overriding/straddling of an atrioventricular valve is a consequence of atrial-ventricular septal malalignment.We sought to characterize the malalignment by analogizing it to a flap-door and using structured approach.Methods:The echocardiograms and magnetic resonance images of 35 patients with overriding/straddling tricuspid or mitral valve were evaluated to assess the following modifiers;the malaligned part of the septum,the reference structure,and the mechanism,direction and severity of malalignment.Results:The pathology included classic overriding tricuspid valve in 15,classic overriding mitral valve in 12,and overriding tricuspid valve with left juxtaposition of atrial appendages in 8.In classic overriding tricuspid valve,the ventricular septum was hinged to the anterior interventricular groove and its insertion to the posterior interventricular groove was displaced toward the right ventricle.The VSD primarily involved the inlet but also extended toward the anterior interventricular groove.In classic overriding mitral valve,the ventricular septum was hinged to the posterior interventricular groove and crux cordis.Its insertion to the anterior interventricular groove was displaced toward the left ventricle.The VSD primarily involved the anterior part but also extended toward the inlet.Overriding tricuspid valve with left juxtaposition of atrial appendages had a mild degree of malalignment with displacement/rotation of the atrioventricular junction.Evenly spaced short-axis images were most helpful in characterizing the pathology.Conclusions:Overriding/straddling atrioventricular valves can be easily understood by analogizing the atrial-ventricular septal malalignment to a flap-door and describing the pathology in a structured manner.Contrary to what has previously been known,the VSD is not limited to the inlet or outlet part of the ventricular septum.
文摘The seismicity along the Himalayan arc varies significantly with some well defined patterns of segmentations.We show that the earthquakes along the Himalayan Seismic Belt(HSB)are influenced by the structural heterogeneities existing in the underthrusting Indian plate as well as by the presence of various north-south trending active rifts in the overriding wedge of the Himalaya.Model calculations of stress distribution show that stress change due to strain accumulation is more on moderately steeper fault,simulating the midcrustal ramp under the southern Higher Himalaya,than on the sub-horizontal thrust.Thus it is surmised that the presence of the ramp which connects the shallow section of seismically active detachment to the aseismically slipping deeper section of the detachment,causes high seismicity in the HSB region.It implies that the seismicity variation along the HSB may also be linked to the presence or absence of the ramp.Further,subsurface ridges on the down-going Indian plate probably control the rupture extent of the great Himalayan earthquakes.Over these ridges the seismicity of the HSB is generally low and it may imply that ramp may be absent in those regions.Finally,we show that the approximately north-south extending active rifts of the Tibetan and Higher Himalaya,cause stress shadow near their southern extent in the HSB which inhibit the occurrence of small and moderate magnitude thrust earthquakes.
基金supported by the National Key Basic Research Project of China (Grant Nos 2011CB302400)the National Natural Science Foundation of China (Grant Nos 60821002, 10871195, 10925105)+1 种基金Major National S&T Project "Advanced CNC Systems"CAS Project "MM Methods for Advanced CNC Systems"
文摘CNC machining plays an important role in mechanical manufacturing.A key issue is to improve the machining feedrate while keeping the machining precision and satisfying the acceleration constraints of the CNC machine.For the consecutive micro-line segments interpolation,the velocities at the junction of two segments are the bottlenecks for the machining efficiency.This paper proposes a multi-period turning method to improve the feedrate at the junctions using the linear acceleration and deceleration mode,which utilizes the maximal acceleration capabilities of the NC machine while satisfying the machining precision.A new and more efficient look-ahead method and a feedrate override method are also proposed to boast the global machining speed.The proposed algorithm has been implemented on Blue Sky NC System,and experimented in real material manufacturing.Compared with several existing algorithms,the current algorithm can improve the manufacturing time ranging from 50% to 180%,depending on the machining parameters,and also results in better machining quality.In addition,the algorithm also satisfies the need of real-time interpolation.
文摘Twenty years ago,far-sighted leaders of China and the Association of Southeast Asian Nations(ASEAN)launched a dialogue that deep-ened mutual understanding and trust,and helped forge close cooperation between the two sides.Since then,China and ASEAN have bolstered part-nerships
基金supported by the Riley Children's Foundation and National Institute of Health for YL and WS.
文摘Tetralogy of Fallot(TOF)is the most prevalent form of cyanotic congenital heart disease(CHD),affecting approximately 3%-5%of infants with CHD,which corresponds to one in 3600 live births(0.28‰).Both males and females are equally affected(Gibbs 2003).The first precise anatomical description of TOF was provided by William Hunter in 1784,although the term“TOF”was coined later by Maude Abbott in 1924 to describe a tetrad consisting of(i)a ventricular septal defect,(ii)an overriding aorta,(iii)right ventricular outflow obstruction,and(iv)right ventricular hypertrophy(Apitz et al.2009).Due to surgical interventions during infancy,85%-90%of TOF patients survive beyond 30 years of age(Ferencz et al.1985;Starr 2010),marking a significant achievement in modern medicine.However,the cause of TOF,like many other forms of congenital heart disease(CHD),remains largely unknown.However,a high recurrence risk of approximately 3%in siblings without other affected first-degree relatives suggests a significant genetic component.In this regard,an original study led by Dr.Guoying Huang and Dr.Wei Sheng and their colleagues provided important evidence linking MST1R as a candidate genetically associated gene to TOF.
