Molecular-frame photoelectron momentum distributions(MF-PMDs) of an H_(2)^(+) molecule ion in the presence of a pair of counter-rotating circularly polarized attosecond extreme ultraviolet laser pulses is studied by n...Molecular-frame photoelectron momentum distributions(MF-PMDs) of an H_(2)^(+) molecule ion in the presence of a pair of counter-rotating circularly polarized attosecond extreme ultraviolet laser pulses is studied by numerically solving the two-dimensional time-dependent Schrodinger equation within the frozen-nuclei approximation. At small time delay, our simulations show that the electron vortex structure is sensitive to the time delay and relative phase between the counterrotating pulses when they are partially overlapped. By adjusting time delay and relative phase, we have the ability to manipulate the MF-PMDs and the appearance of spiral arms. We further show that the internuclear distance can affect the spiral vortices due to its different transition cross sections in the parallel and perpendicular geometries. The lowest-order perturbation theory is employed to interpret these phenomena qualitatively. It is concluded that the internuclear distancedependent transition cross sections and the confinement effect in diatomic molecules are responsible for the variation of vortex structures in the MF-PMDs.展开更多
BACKGROUND Superimposed high-frequency jet ventilation(SHFJV)is suitable for respiratory motion reduction and essential for effective lung tumor ablation.Fluid filling of the target lung wing one-lung flooding(OLF)is ...BACKGROUND Superimposed high-frequency jet ventilation(SHFJV)is suitable for respiratory motion reduction and essential for effective lung tumor ablation.Fluid filling of the target lung wing one-lung flooding(OLF)is necessary for therapeutic ultrasound applications.However,whether unilateral SHFJV allows adequate hemodynamics and gas exchange is unclear.AIM To compared SHFJV with pressure-controlled ventilation(PCV)during OLF by assessing hemodynamics and gas exchange in different animal positions.METHODS SHFJV or PCV was used alternatingly to ventilate the non-flooded lungs of the 12 anesthetized pigs during OLF.The animal positions were changed from left lateral position to supine position(SP)to right lateral position(RLP)every 30 min.In each position,ventilation was maintained for 15 min in both modalities.Hemodynamic variables and arterial blood gas levels were repeatedly measured.RESULTS Unilateral SHFJV led to lower carbon dioxide removal than PCV without abnormally elevated carbon dioxide levels.SHFJV slightly decreased oxygenation in SP and RLP compared with PCV;the lowest values of PaO_(2) and PaO_(2)/FiO_(2) ratio were found in SP[13.0;interquartile range(IQR):12.6-5.6 and 32.5(IQR:31.5-38.9)kPa].Conversely,during SHFJV,the shunt fraction was higher in all animal positions(highest in the RLP:0.30).CONCLUSION In porcine model,unilateral SHFJV may provide adequate ventilation in different animal positions during OLF.Lower oxygenation and CO_(2) removal rates compared to PCV did not lead to hypoxia or hypercapnia.SHFJV can be safely used for lung tumor ablation to minimize ventilation-induced lung motion.展开更多
Background:Acute improvement in range of motion(ROM)is a widely reported effect of stretching and foam rolling,which is commonly explained by changes in pain threshold and/or musculotendinous stiffness.Interestingly,t...Background:Acute improvement in range of motion(ROM)is a widely reported effect of stretching and foam rolling,which is commonly explained by changes in pain threshold and/or musculotendinous stiffness.Interestingly,these effects were also reported in response to various other active and passive interventions that induce responses such as enhanced muscle temperature.Therefore,we hypothesized that acute ROM enhancements could be induced by a wide variety of interventions other than stretching or foam rolling that promote an increase in muscle temperature.Methods:After a systematic search in PubMed,Web of Science,and SPORTDiscus databases,38 studies comparing the effects of stretching and foam rolling with several other interventions on ROM and passive properties were included.These studies had 1134 participants in total,and the data analysis resulted in 140 effect sizes(ESs).ES calculations were performed using robust variance estimation model with R-package.Results:Study quality of the included studies was classified as fair(PEDro score=4.58)with low to moderate certainty of evidence.Results showed no significant differences in ROM(ES=0.01,p=0.88),stiffness(ES=0.09,p=0.67),or passive peak torque(ES=-0.30,p=0.14)between stretching or foam rolling and the other identified activities.Funnel plots revealed no publication bias.Conclusion:Based on current literature,our results challenge the established view on stretching and foam rolling as a recommended component of warm-up programs.The lack of significant difference between interventions suggests there is no need to emphasize stretching or foam rolling to induce acute ROM,passive peak torque increases,or stiffness reductions.展开更多
Background:Cholestasis should be relieved by biliary drainage prior to major liver resection.This condition is often associated with bacterial colonization of the otherwise sterile biliary system.Cholangitis reduces t...Background:Cholestasis should be relieved by biliary drainage prior to major liver resection.This condition is often associated with bacterial colonization of the otherwise sterile biliary system.Cholangitis reduces the regenerative capacity of the remaining liver.Therefore,targeted antibiotic therapy is a key feature in perioperative treatment in patients with perihilar cholangiocarcinoma(pCCC).Methods:Between December 1999 and December 2017,251 pCCC patients were treated in our center.In total,115 patients underwent a microbiological analysis.In addition to the characterization of the specific microorganisms and antibiotic resistance,we analyzed subgroups according to preoperative intervention.Results:Enterococci(87/254,34%)and Enterobacteria(65/254,26%)were the most frequently detected genera.In 43%(50/115)of patients,Enterococcus faecalis was found in the bile duct sample.Enterococcus faecium(29/115)and Escherichia coli(29/115)were detected in 25%of patients.In patients with percutaneous transhepatic biliary drainage(3/8,38%)or stents(24/79,30%),Enterococcus faecium was diagnosed most frequently(P<0.05).Enterococcus faecium and Klebsiella oxytoca were significantly more frequently noted in the time period after 2012(P<0.05).With regard to fungal colonization,the focus was on various Candida strains,but these strains generally lacked resistance.Conclusions:pCCC patients exhibit specific bacterial colonization features depending on the type of preoperative biliary intervention.Specifically,targeted antibiosis should be applied in this patient cohort to minimize the risk of biliary complications after major liver resection.In our cohort,the combination of meropenem and vancomycin represents an effective perioperative medical approach.展开更多
The carrier-envelope phase(CEP)φ_(0)is one of the key parameters in the generation of isolated attosecond pulses.In particular,“cosine”pulses(φ_(0)=0)are best suited for generation of single attosecond pulses in a...The carrier-envelope phase(CEP)φ_(0)is one of the key parameters in the generation of isolated attosecond pulses.In particular,“cosine”pulses(φ_(0)=0)are best suited for generation of single attosecond pulses in atomic media.Such“cosine”pulses have the peak of the most intense cycle aligned with the peak of the pulse envelope,and therefore have the highest contrast between the peak intensity and the neighboring cycles.In this paper,the dynamics of single attosecond pulse generation from a relativistically oscillating plasma mirror is investigated.We use an elementary analytical model as well as particle-in-cell simulations to study few-cycle attosecond pulses.We find that the phase of the field driving the surface oscillations depends on the plasma density and preplasma scale length.This leads us to a counterintuitive conclusion:for the case of normal incidence and a sharp plasma-vacuum boundary,the CEP required for the generation of a single attosecond pulse phase is closer toφ_(0)=π/2(a“sine”pulse),with the exact value depending on the plasma parameters.展开更多
The solar radiation that hits the Earth conditions the dynamic equilibrium that prevails on our planet. Consideration of basic physical-chemical knowledge shows that this equilibrium can be changed only by additional ...The solar radiation that hits the Earth conditions the dynamic equilibrium that prevails on our planet. Consideration of basic physical-chemical knowledge shows that this equilibrium can be changed only by additional energy input or prolongation of the interaction time solar radiation—Earth matter. The contribution of H<sub>2</sub>O(g) and CO<sub>2</sub> to the protection of the earth against excessive warming is experimentally and by basic laws of nature secured. For a greenhouse effect, a part of the earth radiation must be radiated back to the earth and then into space. If one understands the earth radiation as radiation of a black body with the average global environmental temperature, from all vibrations normal modes of the gases H<sub>2</sub>O(g) and CO<sub>2</sub> only the bending mode of CO<sub>2</sub> with 4% of the solar constant can contribute beside the rotational modes of the water to the greenhouse effect. The contributions of the normal modes of H<sub>2</sub>O(g) and CO<sub>2</sub> to the heat capacity of the atmosphere are negligible. Therefore, in agreement with studies by K. Ångström, CO<sub>2</sub> contributes only to the stabilization of the global environmental temperature. Whether the use of renewable energies can actually at least mitigate the increase of the environmental temperature is by no means certain but must be examined for each individual case. With certainty, this goal can only be achieved by reducing the energy consumption of mankind.展开更多
The present work aims to demonstrate the capabilities of Laser-induced Breakdown Spectroscopy(LIBS)coupled with a multivariate technique for rapid quantification and classification of old Indian coins made of various ...The present work aims to demonstrate the capabilities of Laser-induced Breakdown Spectroscopy(LIBS)coupled with a multivariate technique for rapid quantification and classification of old Indian coins made of various alloys.Thirteen old Indian coins in different years of circulation,(1922–1986)were selected for the study.The concentrations were determined by Calibration free LIBS(CF-LIBS)method.The concentration of cuprum(Cu)is negligible,and aluminum(Al)is maximum in the first five coins,and vice-versa in the remaining eight coins.Two different multivariate methods,Principal Component Analysis(PCA)and Soft Independent Modelling of Class Analogy(SIMCA)have been used to classify and identify the coins.PCA classified all thirteen samples into four main alloy categories.The discernment of unknown samples to their probable class membership of alloy was performed using SIMCA.The surface hardness(Brinell hardness number)is linearly correlated with the plasma temperature and LIBS intensity ratios.The sample surface of the first and fifth coin belongs to Al-alloy,having the least surface hardness,and it became harder for Cu–Ni alloy,Ni-brass alloy,and bronze alloy.The hardness of the surface is more for bronze sample twelve.It is also observed that the plasma temperature increases monotonically with the Brinell hardness number.This analysis provides valuable information on fabrication methodology and explains large diversification in the elementary composition of old coins.展开更多
目的基于面部三维动态定量分析系统(3-Dimensional Analysis System for Facial Motion,3D-ASFM)对健康受试者及面瘫患者健侧面部测量,探讨面瘫后健侧面部静态和动态指标的变化。方法纳入23例单侧面瘫患者,匹配年龄相当的健康受试者作...目的基于面部三维动态定量分析系统(3-Dimensional Analysis System for Facial Motion,3D-ASFM)对健康受试者及面瘫患者健侧面部测量,探讨面瘫后健侧面部静态和动态指标的变化。方法纳入23例单侧面瘫患者,匹配年龄相当的健康受试者作为对照。同时纳入74例不同年龄段的单侧面瘫患者。对所有受试者均进行面部主观评估(House-Brackmann分级和Sunnybrook评分)和面部三维动态测量。比较面瘫患者健侧面部动静态指标与正常人面部指标的差异。分析健侧指标是否受年龄、性别、面瘫程度及侧别等影响。结果面瘫患者健侧静态指标各数值均大于正常人。部分动态指标为面瘫组大于对照组,余指标未见明显统计学差异。与对照组相比,面瘫后男女间上下睑间距差异更明显,但动态指标无显著性差异。健侧除了鼻唇沟宽度与年龄有一定正相关性外,余指标未明显受年龄影响。不同面瘫侧别患者健侧指标无显著性差异。面瘫的程度与健侧指标无明显相关性。结论面瘫之后,患者健侧面部无论是静态还是运动均会发生改变,大部分改变与面瘫程度、年龄、性别、侧别等无关。展开更多
基金Project supported by the Natural Science Foundation of Jilin Province,China (Grant No.20220101016JC)the National Key Research and Development Program of China (Grant No.2022YFE0134200)+1 种基金the National Natural Science Foundation of China (Grant Nos.12174147,91850114,and 11774131)the Open Research Fund of State Key Laboratory of Transient Optics and Photonics。
文摘Molecular-frame photoelectron momentum distributions(MF-PMDs) of an H_(2)^(+) molecule ion in the presence of a pair of counter-rotating circularly polarized attosecond extreme ultraviolet laser pulses is studied by numerically solving the two-dimensional time-dependent Schrodinger equation within the frozen-nuclei approximation. At small time delay, our simulations show that the electron vortex structure is sensitive to the time delay and relative phase between the counterrotating pulses when they are partially overlapped. By adjusting time delay and relative phase, we have the ability to manipulate the MF-PMDs and the appearance of spiral arms. We further show that the internuclear distance can affect the spiral vortices due to its different transition cross sections in the parallel and perpendicular geometries. The lowest-order perturbation theory is employed to interpret these phenomena qualitatively. It is concluded that the internuclear distancedependent transition cross sections and the confinement effect in diatomic molecules are responsible for the variation of vortex structures in the MF-PMDs.
文摘BACKGROUND Superimposed high-frequency jet ventilation(SHFJV)is suitable for respiratory motion reduction and essential for effective lung tumor ablation.Fluid filling of the target lung wing one-lung flooding(OLF)is necessary for therapeutic ultrasound applications.However,whether unilateral SHFJV allows adequate hemodynamics and gas exchange is unclear.AIM To compared SHFJV with pressure-controlled ventilation(PCV)during OLF by assessing hemodynamics and gas exchange in different animal positions.METHODS SHFJV or PCV was used alternatingly to ventilate the non-flooded lungs of the 12 anesthetized pigs during OLF.The animal positions were changed from left lateral position to supine position(SP)to right lateral position(RLP)every 30 min.In each position,ventilation was maintained for 15 min in both modalities.Hemodynamic variables and arterial blood gas levels were repeatedly measured.RESULTS Unilateral SHFJV led to lower carbon dioxide removal than PCV without abnormally elevated carbon dioxide levels.SHFJV slightly decreased oxygenation in SP and RLP compared with PCV;the lowest values of PaO_(2) and PaO_(2)/FiO_(2) ratio were found in SP[13.0;interquartile range(IQR):12.6-5.6 and 32.5(IQR:31.5-38.9)kPa].Conversely,during SHFJV,the shunt fraction was higher in all animal positions(highest in the RLP:0.30).CONCLUSION In porcine model,unilateral SHFJV may provide adequate ventilation in different animal positions during OLF.Lower oxygenation and CO_(2) removal rates compared to PCV did not lead to hypoxia or hypercapnia.SHFJV can be safely used for lung tumor ablation to minimize ventilation-induced lung motion.
文摘Background:Acute improvement in range of motion(ROM)is a widely reported effect of stretching and foam rolling,which is commonly explained by changes in pain threshold and/or musculotendinous stiffness.Interestingly,these effects were also reported in response to various other active and passive interventions that induce responses such as enhanced muscle temperature.Therefore,we hypothesized that acute ROM enhancements could be induced by a wide variety of interventions other than stretching or foam rolling that promote an increase in muscle temperature.Methods:After a systematic search in PubMed,Web of Science,and SPORTDiscus databases,38 studies comparing the effects of stretching and foam rolling with several other interventions on ROM and passive properties were included.These studies had 1134 participants in total,and the data analysis resulted in 140 effect sizes(ESs).ES calculations were performed using robust variance estimation model with R-package.Results:Study quality of the included studies was classified as fair(PEDro score=4.58)with low to moderate certainty of evidence.Results showed no significant differences in ROM(ES=0.01,p=0.88),stiffness(ES=0.09,p=0.67),or passive peak torque(ES=-0.30,p=0.14)between stretching or foam rolling and the other identified activities.Funnel plots revealed no publication bias.Conclusion:Based on current literature,our results challenge the established view on stretching and foam rolling as a recommended component of warm-up programs.The lack of significant difference between interventions suggests there is no need to emphasize stretching or foam rolling to induce acute ROM,passive peak torque increases,or stiffness reductions.
文摘Background:Cholestasis should be relieved by biliary drainage prior to major liver resection.This condition is often associated with bacterial colonization of the otherwise sterile biliary system.Cholangitis reduces the regenerative capacity of the remaining liver.Therefore,targeted antibiotic therapy is a key feature in perioperative treatment in patients with perihilar cholangiocarcinoma(pCCC).Methods:Between December 1999 and December 2017,251 pCCC patients were treated in our center.In total,115 patients underwent a microbiological analysis.In addition to the characterization of the specific microorganisms and antibiotic resistance,we analyzed subgroups according to preoperative intervention.Results:Enterococci(87/254,34%)and Enterobacteria(65/254,26%)were the most frequently detected genera.In 43%(50/115)of patients,Enterococcus faecalis was found in the bile duct sample.Enterococcus faecium(29/115)and Escherichia coli(29/115)were detected in 25%of patients.In patients with percutaneous transhepatic biliary drainage(3/8,38%)or stents(24/79,30%),Enterococcus faecium was diagnosed most frequently(P<0.05).Enterococcus faecium and Klebsiella oxytoca were significantly more frequently noted in the time period after 2012(P<0.05).With regard to fungal colonization,the focus was on various Candida strains,but these strains generally lacked resistance.Conclusions:pCCC patients exhibit specific bacterial colonization features depending on the type of preoperative biliary intervention.Specifically,targeted antibiosis should be applied in this patient cohort to minimize the risk of biliary complications after major liver resection.In our cohort,the combination of meropenem and vancomycin represents an effective perioperative medical approach.
基金This work was supported by the Russian Science Foundation(Grant No.22-22-01031).
文摘The carrier-envelope phase(CEP)φ_(0)is one of the key parameters in the generation of isolated attosecond pulses.In particular,“cosine”pulses(φ_(0)=0)are best suited for generation of single attosecond pulses in atomic media.Such“cosine”pulses have the peak of the most intense cycle aligned with the peak of the pulse envelope,and therefore have the highest contrast between the peak intensity and the neighboring cycles.In this paper,the dynamics of single attosecond pulse generation from a relativistically oscillating plasma mirror is investigated.We use an elementary analytical model as well as particle-in-cell simulations to study few-cycle attosecond pulses.We find that the phase of the field driving the surface oscillations depends on the plasma density and preplasma scale length.This leads us to a counterintuitive conclusion:for the case of normal incidence and a sharp plasma-vacuum boundary,the CEP required for the generation of a single attosecond pulse phase is closer toφ_(0)=π/2(a“sine”pulse),with the exact value depending on the plasma parameters.
文摘The solar radiation that hits the Earth conditions the dynamic equilibrium that prevails on our planet. Consideration of basic physical-chemical knowledge shows that this equilibrium can be changed only by additional energy input or prolongation of the interaction time solar radiation—Earth matter. The contribution of H<sub>2</sub>O(g) and CO<sub>2</sub> to the protection of the earth against excessive warming is experimentally and by basic laws of nature secured. For a greenhouse effect, a part of the earth radiation must be radiated back to the earth and then into space. If one understands the earth radiation as radiation of a black body with the average global environmental temperature, from all vibrations normal modes of the gases H<sub>2</sub>O(g) and CO<sub>2</sub> only the bending mode of CO<sub>2</sub> with 4% of the solar constant can contribute beside the rotational modes of the water to the greenhouse effect. The contributions of the normal modes of H<sub>2</sub>O(g) and CO<sub>2</sub> to the heat capacity of the atmosphere are negligible. Therefore, in agreement with studies by K. Ångström, CO<sub>2</sub> contributes only to the stabilization of the global environmental temperature. Whether the use of renewable energies can actually at least mitigate the increase of the environmental temperature is by no means certain but must be examined for each individual case. With certainty, this goal can only be achieved by reducing the energy consumption of mankind.
文摘The present work aims to demonstrate the capabilities of Laser-induced Breakdown Spectroscopy(LIBS)coupled with a multivariate technique for rapid quantification and classification of old Indian coins made of various alloys.Thirteen old Indian coins in different years of circulation,(1922–1986)were selected for the study.The concentrations were determined by Calibration free LIBS(CF-LIBS)method.The concentration of cuprum(Cu)is negligible,and aluminum(Al)is maximum in the first five coins,and vice-versa in the remaining eight coins.Two different multivariate methods,Principal Component Analysis(PCA)and Soft Independent Modelling of Class Analogy(SIMCA)have been used to classify and identify the coins.PCA classified all thirteen samples into four main alloy categories.The discernment of unknown samples to their probable class membership of alloy was performed using SIMCA.The surface hardness(Brinell hardness number)is linearly correlated with the plasma temperature and LIBS intensity ratios.The sample surface of the first and fifth coin belongs to Al-alloy,having the least surface hardness,and it became harder for Cu–Ni alloy,Ni-brass alloy,and bronze alloy.The hardness of the surface is more for bronze sample twelve.It is also observed that the plasma temperature increases monotonically with the Brinell hardness number.This analysis provides valuable information on fabrication methodology and explains large diversification in the elementary composition of old coins.
文摘目的基于面部三维动态定量分析系统(3-Dimensional Analysis System for Facial Motion,3D-ASFM)对健康受试者及面瘫患者健侧面部测量,探讨面瘫后健侧面部静态和动态指标的变化。方法纳入23例单侧面瘫患者,匹配年龄相当的健康受试者作为对照。同时纳入74例不同年龄段的单侧面瘫患者。对所有受试者均进行面部主观评估(House-Brackmann分级和Sunnybrook评分)和面部三维动态测量。比较面瘫患者健侧面部动静态指标与正常人面部指标的差异。分析健侧指标是否受年龄、性别、面瘫程度及侧别等影响。结果面瘫患者健侧静态指标各数值均大于正常人。部分动态指标为面瘫组大于对照组,余指标未见明显统计学差异。与对照组相比,面瘫后男女间上下睑间距差异更明显,但动态指标无显著性差异。健侧除了鼻唇沟宽度与年龄有一定正相关性外,余指标未明显受年龄影响。不同面瘫侧别患者健侧指标无显著性差异。面瘫的程度与健侧指标无明显相关性。结论面瘫之后,患者健侧面部无论是静态还是运动均会发生改变,大部分改变与面瘫程度、年龄、性别、侧别等无关。
