BACKGROUND Hypovolemic shock can lead to life-threatening organ dysfunction,and adequate fluid administration is a fundamental therapy.Traditionally,parameters such as vital signs,central venous pressure,and urine out...BACKGROUND Hypovolemic shock can lead to life-threatening organ dysfunction,and adequate fluid administration is a fundamental therapy.Traditionally,parameters such as vital signs,central venous pressure,and urine output have been used to estimate intravascular volume.Recently,pulse pressure variation(PPV)and non-invasive cardiac monitoring devices have been introduced.In this case report,we introduce a patient with massive active bleeding from giant renal angiomyolipoma(AML).During emergent nephrectomy,we used non-invasive cardiac monitoring with CSN-1901(Nihon Kohden,Tokyo,Japan)and PPV to evaluate the patient's intravascular volume status to achieve optimal fluid management.CASE SUMMARY A 30-year-old male patient with giant AML with active bleeding was referred to the emergency room complaining of severe abdominal pain and spontaneous abdominal distension.AML was diagnosed by computed tomography,and emergent nephrectomy was scheduled.Massive bleeding was expected so we decided to use non-invasive cardiac monitoring and PPV to assist fluid therapy because they are relatively easy and fast compared to invasive cardiac monitoring.During the surgery,6000 mL of estimated blood loss occurred.Along with the patient's vital signs and laboratory results,we monitored cardiac output,cardiac output,stroke volume,stroke volume index with a non-invasive cardiac monitoring device,and PPV using an intra-arterial catheter to evaluate intravascular volume status of the patient to compensate for massive bleeding.CONCLUSION In addition to traditional parameters,non-invasive cardiac monitoring and PPV are useful methods to evaluate patient's intravascular volume status and provideguidance for intraoperative management of hypovolemic shock patients.展开更多
The first automatic algorithm was designed to estimate the pulse pressure variation (PPVPPV) from arterial blood pressure (ABP) signals under spontaneous breathing conditions. While currently there are a few publicly ...The first automatic algorithm was designed to estimate the pulse pressure variation (PPVPPV) from arterial blood pressure (ABP) signals under spontaneous breathing conditions. While currently there are a few publicly available algorithms to automatically estimate PPVPPV accurately and reliably in mechani-cally ventilated subjects, at the moment there is no automatic algorithm for estimating PPVPPV on sponta-neously breathing subjects. The algorithm utilizes our recently developed sequential Monte Carlo method (SMCM), which is called a maximum a-posteriori adaptive marginalized particle filter (MAM-PF). The performance assessment results of the proposed algorithm on real ABP signals from spontaneously breath-ing subjects were reported.展开更多
Based on the documentation of the invited paper and the subsequent discussion at a virtual conference,discoveries are indicated,which are summarized in the following paper for further evaluation on the topic of non-th...Based on the documentation of the invited paper and the subsequent discussion at a virtual conference,discoveries are indicated,which are summarized in the following paper for further evaluation on the topic of non-thermal forces using terms of extremely powerful components of Maxwell’s stress tensor at the interaction of CPA(chirped pulse amplification)laser pulses in the fusion plasmas of hydrogen with the isotope 11 of boron.This is caused by a recoil mechanism given by the Fresnel formulas of the suppression of the reflectivity of inhomogeneous plasma given by optical constants of the plasma properties.展开更多
Natural characteristics of thin?wall pipe of the compressor under uniformly distributed pressure were presented in this paper based on a cylindrical shell model. In the traditional method, the beam model was usually u...Natural characteristics of thin?wall pipe of the compressor under uniformly distributed pressure were presented in this paper based on a cylindrical shell model. In the traditional method, the beam model was usually used to analyze the pipe system. In actual fact, the pipe segment of the compressor was always broken in the form of a long crack or a partial hole and the phenomenon was hardly explained by beam model. According to the structure characteristic of compressor pipe segment, whose radius is large and thickness is little, shell model shows the advantage in this kind of pipe problem. Based on Sanders' shell theory, the vibration di erential equation of pipe was established by apply?ing the energy method. The influences of length to radius ratio(L/R), thickness to radius ratio(h/R), circumferential wave number(n) and pressure(q) on the natural frequencies of pipe were analyzed. The study shows: Pressure and structural parameters have a great e ect on the natural characteristics of the pipe. Natural frequency increases as the pressure increases, especially for the higher mode. The sensitivity of natural frequency on pressure becomes stronger with h/R ratio increases; when L/R ratio is greater than a certain critical value, the influence of the pressure on natural frequency will no longer be obvious. The value of n corresponding to the minimum natural frequency also depends on the value of pressure. In the end, analysis of the forced vibration of a specific pipeline model was given and the modal shapes were illustrated to understand the break of the pipe. The research here will provide the theory support for the dynamic design of related pressure pipe and further experiment study should be employed.展开更多
Pressure and proximity measurements made in a tunnel indicate that a typical vehicle passage produced on the tunnel roof an initial pressure increase of small magnitude,followed by a sharp and more substantial drop in...Pressure and proximity measurements made in a tunnel indicate that a typical vehicle passage produced on the tunnel roof an initial pressure increase of small magnitude,followed by a sharp and more substantial drop in pressure below atmospheric.The magnitude of the pressure drop was found to increase with smaller clearances between the vehicle top and the tunnel roof,consistent with the Bernoulli relation and the vehicle speed.The dynamic pressures potentially may have significant effects on the vibration and noise environments on the lower floors of“air rights construction”buildings that span highways.展开更多
In this paper,after the successful applications to open water propeller performance estimations,the influence of transition sensitive and modified mass transfer models tuned to account for the laminar flow in the pred...In this paper,after the successful applications to open water propeller performance estimations,the influence of transition sensitive and modified mass transfer models tuned to account for the laminar flow in the prediction of the cavitation inception of marine propulsors is investigated from the point of view of the unsteady functioning and induced pressure pulses.The VP1304(also known as PPTC)test case,for which dedicated data were collected during several workshops,is considered first.After preliminary analyses using RANS,also Detached Eddy Simulations(DES)are included to better account for the vortex dynamics and its influence on pressure pulses.Similarly to what observed in uniform inflow,results show a better agreement with the available measurements of propeller performances and confirm the reliability of the proposed approaches for unsteady,non-cavitating,model scale propeller predictions.The overall cavitation pattern is improved too by the application of the transition sensitive correction to the mass transfer model,but the complex dynamics of bubble cavitation observed in experiments prevents quantitatively better predictions in terms of thrust/torque breakdown and induced pressure pulses levels regardless the use of RANS or DES methods.展开更多
<strong>Aim: </strong>To establish the prevalence of iron deficiency anemia and its clinical predictors in Emirati patients with type 2 diabetes. <strong>Patients & Methods:</strong> 237 pa...<strong>Aim: </strong>To establish the prevalence of iron deficiency anemia and its clinical predictors in Emirati patients with type 2 diabetes. <strong>Patients & Methods:</strong> 237 patients were included in the study. A full blood count was obtained in addition to routine blood and urine tests for all patients. Hemoglobin level and iron studies were done for diagnosis of anemia. Statistical analysis was done to find out the prevalence and independent predictors of anemia in the study population of Emirati type 2 diabetic patients.<strong> Results:</strong> Of the studied 237 patients;36.3% had iron deficiency anemia as per the WHO criteria. Independent predictors of iron deficiency anemia were age ≥ 60 years, female gender and wide pulse pressure ≥ 60 mmHg. Hemoglobin level was directly proportionate to e GFR (p < 0.001). Participants with age ≥ 60 years had 4.2 times higher odds to exhibit anemia. Female participants had 1.95 times higher odds to exhibit anemia. Participants with wide pulse pressure ≥ 60 mmHg have 2.4 higher odds to exhibit anemia. <strong>Conclusion: </strong>Iron deficiency anemia is common in type 2 diabetic patients. Testing the patient for iron deficiency anemia should be considered in type 2 diabetes patients especially with age ≥ 60 years, female patients and those with wide pulse pressure ≥ 60 mmHg.展开更多
Ultra-high temperature ceramics (UHTCs) are most recently getting much attention for structural parts of hypersonic missiles with their cruising speed of more than Mach 5. Most of the UHTCs are poor sinterability carb...Ultra-high temperature ceramics (UHTCs) are most recently getting much attention for structural parts of hypersonic missiles with their cruising speed of more than Mach 5. Most of the UHTCs are poor sinterability carbides, nitrides, and borides. Therefore, they have been studied and developed for a long time. However, there are still many problems to solve. In this paper, based on the solid-state reaction presented as an equation of (x + y)·ZrC + 2·y·B → x·ZrC + y·ZrB<sub>2</sub> + y·C, three-phase ZrC/ZrB<sub>2</sub>/C composites have been fabricated from ZrC and amorphous B powders using pulsed electric-current pressure sintering at 1373 to 2173 K for 6.0 × 10<sup>2</sup> s under 50 MPa in a vacuum. ZrC/ZrB2/C = 30/70/C~70/30/C vol% composites with the relative densities D<sub>r</sub> of 96.6 to 98.7% were obtained at 2073 K. The 60/40/C vol% composite revealed high bending strength σ<sub>b</sub> (554 MPa), Vickers hardness H<sub>v</sub> (19.2 GPa) and moderate fracture toughness K<sub>IC</sub> (5.25 MPa·m<sup>1/2</sup>) at room temperature. Furthermore, all composites showed elastic deformation up to 1873 K and revealed σ<sub>b</sub> more than 600 MPa at this temperature, in addition, some composites showed higher σ<sub>b</sub> than 900 MPa at the same temperature. These high mechanical behaviors are discussed with those of the simple binary ZrC/ZrB<sub>2</sub> composites which were fabricated under the same conditions except for their starting materials. The best mechanical properties of binary composites were σ<sub>b</sub> (474 MPa), H<sub>v</sub> (18.5 GPa), and K<sub>IC</sub> (4.45 MPa·m<sup>1/2</sup>) at room temperature, and σ<sub>b</sub> of 400 - 700 MPa at 1873 K. Overall, three-phase composites, nevertheless including soft carbon, have higher mechanical properties than the binary composites.展开更多
文摘BACKGROUND Hypovolemic shock can lead to life-threatening organ dysfunction,and adequate fluid administration is a fundamental therapy.Traditionally,parameters such as vital signs,central venous pressure,and urine output have been used to estimate intravascular volume.Recently,pulse pressure variation(PPV)and non-invasive cardiac monitoring devices have been introduced.In this case report,we introduce a patient with massive active bleeding from giant renal angiomyolipoma(AML).During emergent nephrectomy,we used non-invasive cardiac monitoring with CSN-1901(Nihon Kohden,Tokyo,Japan)and PPV to evaluate the patient's intravascular volume status to achieve optimal fluid management.CASE SUMMARY A 30-year-old male patient with giant AML with active bleeding was referred to the emergency room complaining of severe abdominal pain and spontaneous abdominal distension.AML was diagnosed by computed tomography,and emergent nephrectomy was scheduled.Massive bleeding was expected so we decided to use non-invasive cardiac monitoring and PPV to assist fluid therapy because they are relatively easy and fast compared to invasive cardiac monitoring.During the surgery,6000 mL of estimated blood loss occurred.Along with the patient's vital signs and laboratory results,we monitored cardiac output,cardiac output,stroke volume,stroke volume index with a non-invasive cardiac monitoring device,and PPV using an intra-arterial catheter to evaluate intravascular volume status of the patient to compensate for massive bleeding.CONCLUSION In addition to traditional parameters,non-invasive cardiac monitoring and PPV are useful methods to evaluate patient's intravascular volume status and provideguidance for intraoperative management of hypovolemic shock patients.
文摘The first automatic algorithm was designed to estimate the pulse pressure variation (PPVPPV) from arterial blood pressure (ABP) signals under spontaneous breathing conditions. While currently there are a few publicly available algorithms to automatically estimate PPVPPV accurately and reliably in mechani-cally ventilated subjects, at the moment there is no automatic algorithm for estimating PPVPPV on sponta-neously breathing subjects. The algorithm utilizes our recently developed sequential Monte Carlo method (SMCM), which is called a maximum a-posteriori adaptive marginalized particle filter (MAM-PF). The performance assessment results of the proposed algorithm on real ABP signals from spontaneously breath-ing subjects were reported.
文摘Based on the documentation of the invited paper and the subsequent discussion at a virtual conference,discoveries are indicated,which are summarized in the following paper for further evaluation on the topic of non-thermal forces using terms of extremely powerful components of Maxwell’s stress tensor at the interaction of CPA(chirped pulse amplification)laser pulses in the fusion plasmas of hydrogen with the isotope 11 of boron.This is caused by a recoil mechanism given by the Fresnel formulas of the suppression of the reflectivity of inhomogeneous plasma given by optical constants of the plasma properties.
基金National Natural Science Foundation of China(Grant No.51575093)Fundamental Research Funds for the Central Universities of China(Grant Nos.N160313001,N170308028)
文摘Natural characteristics of thin?wall pipe of the compressor under uniformly distributed pressure were presented in this paper based on a cylindrical shell model. In the traditional method, the beam model was usually used to analyze the pipe system. In actual fact, the pipe segment of the compressor was always broken in the form of a long crack or a partial hole and the phenomenon was hardly explained by beam model. According to the structure characteristic of compressor pipe segment, whose radius is large and thickness is little, shell model shows the advantage in this kind of pipe problem. Based on Sanders' shell theory, the vibration di erential equation of pipe was established by apply?ing the energy method. The influences of length to radius ratio(L/R), thickness to radius ratio(h/R), circumferential wave number(n) and pressure(q) on the natural frequencies of pipe were analyzed. The study shows: Pressure and structural parameters have a great e ect on the natural characteristics of the pipe. Natural frequency increases as the pressure increases, especially for the higher mode. The sensitivity of natural frequency on pressure becomes stronger with h/R ratio increases; when L/R ratio is greater than a certain critical value, the influence of the pressure on natural frequency will no longer be obvious. The value of n corresponding to the minimum natural frequency also depends on the value of pressure. In the end, analysis of the forced vibration of a specific pipeline model was given and the modal shapes were illustrated to understand the break of the pipe. The research here will provide the theory support for the dynamic design of related pressure pipe and further experiment study should be employed.
文摘Pressure and proximity measurements made in a tunnel indicate that a typical vehicle passage produced on the tunnel roof an initial pressure increase of small magnitude,followed by a sharp and more substantial drop in pressure below atmospheric.The magnitude of the pressure drop was found to increase with smaller clearances between the vehicle top and the tunnel roof,consistent with the Bernoulli relation and the vehicle speed.The dynamic pressures potentially may have significant effects on the vibration and noise environments on the lower floors of“air rights construction”buildings that span highways.
文摘In this paper,after the successful applications to open water propeller performance estimations,the influence of transition sensitive and modified mass transfer models tuned to account for the laminar flow in the prediction of the cavitation inception of marine propulsors is investigated from the point of view of the unsteady functioning and induced pressure pulses.The VP1304(also known as PPTC)test case,for which dedicated data were collected during several workshops,is considered first.After preliminary analyses using RANS,also Detached Eddy Simulations(DES)are included to better account for the vortex dynamics and its influence on pressure pulses.Similarly to what observed in uniform inflow,results show a better agreement with the available measurements of propeller performances and confirm the reliability of the proposed approaches for unsteady,non-cavitating,model scale propeller predictions.The overall cavitation pattern is improved too by the application of the transition sensitive correction to the mass transfer model,but the complex dynamics of bubble cavitation observed in experiments prevents quantitatively better predictions in terms of thrust/torque breakdown and induced pressure pulses levels regardless the use of RANS or DES methods.
文摘<strong>Aim: </strong>To establish the prevalence of iron deficiency anemia and its clinical predictors in Emirati patients with type 2 diabetes. <strong>Patients & Methods:</strong> 237 patients were included in the study. A full blood count was obtained in addition to routine blood and urine tests for all patients. Hemoglobin level and iron studies were done for diagnosis of anemia. Statistical analysis was done to find out the prevalence and independent predictors of anemia in the study population of Emirati type 2 diabetic patients.<strong> Results:</strong> Of the studied 237 patients;36.3% had iron deficiency anemia as per the WHO criteria. Independent predictors of iron deficiency anemia were age ≥ 60 years, female gender and wide pulse pressure ≥ 60 mmHg. Hemoglobin level was directly proportionate to e GFR (p < 0.001). Participants with age ≥ 60 years had 4.2 times higher odds to exhibit anemia. Female participants had 1.95 times higher odds to exhibit anemia. Participants with wide pulse pressure ≥ 60 mmHg have 2.4 higher odds to exhibit anemia. <strong>Conclusion: </strong>Iron deficiency anemia is common in type 2 diabetic patients. Testing the patient for iron deficiency anemia should be considered in type 2 diabetes patients especially with age ≥ 60 years, female patients and those with wide pulse pressure ≥ 60 mmHg.
文摘Ultra-high temperature ceramics (UHTCs) are most recently getting much attention for structural parts of hypersonic missiles with their cruising speed of more than Mach 5. Most of the UHTCs are poor sinterability carbides, nitrides, and borides. Therefore, they have been studied and developed for a long time. However, there are still many problems to solve. In this paper, based on the solid-state reaction presented as an equation of (x + y)·ZrC + 2·y·B → x·ZrC + y·ZrB<sub>2</sub> + y·C, three-phase ZrC/ZrB<sub>2</sub>/C composites have been fabricated from ZrC and amorphous B powders using pulsed electric-current pressure sintering at 1373 to 2173 K for 6.0 × 10<sup>2</sup> s under 50 MPa in a vacuum. ZrC/ZrB2/C = 30/70/C~70/30/C vol% composites with the relative densities D<sub>r</sub> of 96.6 to 98.7% were obtained at 2073 K. The 60/40/C vol% composite revealed high bending strength σ<sub>b</sub> (554 MPa), Vickers hardness H<sub>v</sub> (19.2 GPa) and moderate fracture toughness K<sub>IC</sub> (5.25 MPa·m<sup>1/2</sup>) at room temperature. Furthermore, all composites showed elastic deformation up to 1873 K and revealed σ<sub>b</sub> more than 600 MPa at this temperature, in addition, some composites showed higher σ<sub>b</sub> than 900 MPa at the same temperature. These high mechanical behaviors are discussed with those of the simple binary ZrC/ZrB<sub>2</sub> composites which were fabricated under the same conditions except for their starting materials. The best mechanical properties of binary composites were σ<sub>b</sub> (474 MPa), H<sub>v</sub> (18.5 GPa), and K<sub>IC</sub> (4.45 MPa·m<sup>1/2</sup>) at room temperature, and σ<sub>b</sub> of 400 - 700 MPa at 1873 K. Overall, three-phase composites, nevertheless including soft carbon, have higher mechanical properties than the binary composites.
