In stock markets,trading volumes serve as a crucial variable,acting as a measure for a security’s liquidity level.To evaluate liquidity risk exposure,we examine the process of volume drawdown and measures of crash-re...In stock markets,trading volumes serve as a crucial variable,acting as a measure for a security’s liquidity level.To evaluate liquidity risk exposure,we examine the process of volume drawdown and measures of crash-recovery within fluctuating time frames.These moving time windows shield our financial indicators from being affected by the massive transaction volume,a characteristic of the opening and closing of stock markets.The empirical study is conducted on the high-frequency financial volumes of Tesla,Netflix,and Apple,spanning from April to September 2022.First,we model the financial volume time series for each stock using a semi-Markov model,known as the weighted-indexed semi-Markov chain(WISMC)model.Second,we calculate both real and synthetic drawdown-based risk indicators for comparison purposes.The findings reveal that our risk measures possess statistically different distributions,contingent on the selected time windows.On a global scale,for all assets,financial risk indicators calculated on data derived from the WISMC model closely align with the real ones in terms of Kullback-Leibler divergence.展开更多
The authors establish some inequalities about the dual mixed volumes of star bodies in Rn. These inequalities are the analogue in the Brunn-Minkowski theory of the inequalities of Marcus-Lopes and Bergstrom about symm...The authors establish some inequalities about the dual mixed volumes of star bodies in Rn. These inequalities are the analogue in the Brunn-Minkowski theory of the inequalities of Marcus-Lopes and Bergstrom about symmetric functions of positive reals.展开更多
In this paper,we define lower-dimensional volumes of spin manifolds with boundary.We compute thelower-dimensional volume Vol^((2,2)) for 5-dimensional and 6-dimensional spin manifolds with boundary and we also getthe ...In this paper,we define lower-dimensional volumes of spin manifolds with boundary.We compute thelower-dimensional volume Vol^((2,2)) for 5-dimensional and 6-dimensional spin manifolds with boundary and we also getthe Kastler-Kalau-Walze type theorem in this case.展开更多
Objective:To study the effects of prolonging small feeding volumes early in life on the incidence of necrotizing enterocolitis(NEC)in very low birth weight(VLBW)preterm infants.Methods:A total of 128 VLBW infants who ...Objective:To study the effects of prolonging small feeding volumes early in life on the incidence of necrotizing enterocolitis(NEC)in very low birth weight(VLBW)preterm infants.Methods:A total of 128 VLBW infants who could not be breastfed were assigned into the experimental group(63 cases)and the control group(65 cases)using a random number table.The experiment group was fed 12 mL/(kg·d)on day 1 which was increased to 24 mL/(kg·d)for the first 10 study days.The control group was fed 12 mL/(kg·d)for the first 14e48 hours.Then,the feeding volume increased by 24-36 mL/(kg·d)up to 140e160 mL/(kg·d)and maintained until the 10th day after birth.The incidence of feeding intolerance and NEC,duration of hospitalization,time to full enteral feedings,incidence of intrahepatic cholestasis,and the levels of gastrin and motilin in serum were assessed.Results:The incidence of feeding intolerance was significantly lower in the experimental group compared with the control group(15.87% vs.33.84%).There was a significant reduction in the incidence of NEC between the experimental and control groups(7.9% vs.16% in the control group).Conclusion:A protocol that prolongs small feeding volumes early in life can reduce the incidence and severity of NEC,but still warrants further study.展开更多
The present work is focusing on the synthesization and physico-chemical properties of Jatropha curcas biodiesel with diesel and alcohols.The densities of binary diesel(2)+1-alkanols(C_(3) or C_(4))(3)and ternary Jatro...The present work is focusing on the synthesization and physico-chemical properties of Jatropha curcas biodiesel with diesel and alcohols.The densities of binary diesel(2)+1-alkanols(C_(3) or C_(4))(3)and ternary Jatropha curcas biodiesel(1)+diesel(2)+1-alkanols(C_(3)or C_(4))(3)blends have been reported over full range of composition at temperatures within range 288.15 to 313.15 K.Also densities of Jatropha curcas biodiesel(1)+diesel or 1-alkanols(C_(3) or C_(4))(2)blends have been measured at 313.15 K.Excess molar volumes,V^E,V^E_(123)of binary and ternary blends were calculated from the measured data and the derived properties were correlated to composition using Redlich-Kister equation.A reasonable agreement was found between the measured and estimated values.Further,densities and excess molar volumes data were reasoned to discuss molecular interactions taking into consideration effect of composition and temperature.展开更多
Previous studies have reported decreased cerebral volume as a result of smoking. However, little is known about accompanying changes in ventricular volume for healthy subjects who smoke, although ventricular volume is...Previous studies have reported decreased cerebral volume as a result of smoking. However, little is known about accompanying changes in ventricular volume for healthy subjects who smoke, although ventricular volume is increased in patients with multiple sclerosis who smoke. The present study analyzed whether cerebral volume decreased with smoking through the use of magnetic resonance imaging. In addition, accompanying changes in ventricular volume that resulted from decreased cerebral volume and smoking were analyzed in healthy subjects. When multivariate analysis of covariance was performed by integrating the 2 age groups, aged 20-28 years and 40-49 years, with statistical significance, results showed that cerebral volume of smokers was smaller and ventricular volume was greater compared with the non-smokers. These findings suggest that ventricular volume changes could be utilized to characterize the effects of smoking.展开更多
AIM:To compare hippocampus and amygdala volumes of patients with vaginismus with those of healthy control subjects.METHODS:Magnetic resonance imaging was performed on ten patients with vaginismus and ten control subje...AIM:To compare hippocampus and amygdala volumes of patients with vaginismus with those of healthy control subjects.METHODS:Magnetic resonance imaging was performed on ten patients with vaginismus and ten control subjects matched for age and gender.Volumes of the hippocampus and amygdala were blindly measured.RESULTS:We found that the mean right amygdala volume of patients with vaginismus were smaller than that of the healthy controls.With regard to hippocampus volumes,the mean left and right hippocampus volumes were smaller than those of the healthy controls.CONCLUSION:Our present findings suggest that there have been hippocampus and amygdala structural abnormalities in patients with vaginismus.These changes provide the notion that vaginismus may be a fear-related condition.展开更多
This paper applies both the neural network and adaptive neuro-fuzzy inference system for forecasting short-term chaotic traffic volumes and compares the results. The architecture of the neural network consists of the ...This paper applies both the neural network and adaptive neuro-fuzzy inference system for forecasting short-term chaotic traffic volumes and compares the results. The architecture of the neural network consists of the input vector, one hidden layer and output layer. Bayesian regularization is employed to obtain the effective number of neurons in the hidden layer. The input variables and target of the adaptive neuro-fuzzy inference system are the same as those of the neural network. The data clustering technique is used to group data points so that the membership functions will be more tailored to the input data, which in turn greatly reduces the number of fuzzy rules. Numerical results indicate that these two models have almost the same accuracy, while the adaptive neuro-fuzzy inference system takes more time to train. It is also shown that although the effective number of neurons in the hidden layer is less than half the number of the input elements, the neural network can have satisfactory performance.展开更多
Purpose: The aim of the present study was to evaluate the diagnostic accuracy for quantification of left ventricular (LV) volumes and LV ejection fraction (LVEF) with current echocardiographic methods of planimetry fo...Purpose: The aim of the present study was to evaluate the diagnostic accuracy for quantification of left ventricular (LV) volumes and LV ejection fraction (LVEF) with current echocardiographic methods of planimetry for analysis of LV remodeling after myocardial infarction in daily clinical routine. Methods: 26 patients were investigated directly after interventional therapy at hospital pre-discharge and at 6 month follow-up. Standardized 2D transthoracic native and contrast echocardiography were performed in all patients. Due to methodological aspects the results of LV volumes and LVEF using native echocardiography were compared to the results of LV opacification (LVO) imaging for analysis in mono-, bi- and triplane data sets using the Simpson’s rule. In addition corresponding multidimensional data sets were analyzed. Results: The assessment of LV volumes and LVEF is more accurate with contrast echocardiography. The comparison of LV volumes and LVEF shows significant increases using contrast echocardiography (p < 0.001). Larger left ventricular end-diastolic volumes (LVEDV) are measured at follow up (p < 0.05). Significant differences (p < 0.001) are found for the determination of LVEDV and LVEF relating to apical mono-, bi-, tri- and multiplane data sets. Standard deviations of the triplane approach, however, are significantly lower than using other modalities. Conclusion: Depending on the localization of the myocardial infarction LV volumes and LVEF are less reliably evaluated using the mono- or biplane approach. According to standardization and simultaneous acquisition of all LV wall segments the triplane approach is currently the best approach to determine LV systolic function. In addition, contrast echocardiography is indicated to improve endocardial border delineation in patients using the triplane or multiplane approach. To our knowledge the present study is the first systematic evaluation of all current possibilities for determination of LV volumes and LVEF by native and contrast echocardiography.展开更多
The control volume method gives the forces which act on the system, but not necessarily the wall pressure of the system. The author has made an attempt to develop a control volume method which makes it possible to obt...The control volume method gives the forces which act on the system, but not necessarily the wall pressure of the system. The author has made an attempt to develop a control volume method which makes it possible to obtain the wall pressure of the control volume. The 2-D inviscid incompressible steady duct flow is considered. The conservation equations in integral form are discretized for a control volume. The circulation along the control surface is expressed as a nonlinear function of the vertical velocity component at the inlet and is set equal to zero for the inviscid flow. The equation is solved by the Newton method, and the other aerodynamic properties can be obtained. The calculated results have been compared to the experiment and the agreement has been found fairly satisfactory.展开更多
In recent years, the rationalization of concrete mix ratios which batches equal volumes of sand and gravel in building projects has been gaining grounds in the Cameroon construction industry. The main objective of thi...In recent years, the rationalization of concrete mix ratios which batches equal volumes of sand and gravel in building projects has been gaining grounds in the Cameroon construction industry. The main objective of this study is therefore to investigate if the concrete produced with rationalized mix ratio can be adopted as conventional mix ratio in terms of minimum required compression strength of concrete for buildings. Specifically this work compared the conventional mix ratio of 350 kg of cement: 400 liters of sand: 800 liters of gravel for a cubic meter and the rationalized batch of 350 kg of cement: 600 liters of sand: 600 liters of 5/15 gravel, 15/25 gravel and a combination of 5/15 + 15/25 gravel. Average compressive tests’results for both the conventional and the rationalized mix ratios were found to meet the minimum compressive strength of 65% at 7 days, 90% at 14 days and 99% at 28 days for gravel size combination 5/15 + 15/25. Single size gravel of 5/15 and 15/25 did not meet the minimum required compressive strength of 20 N/mm<sup>2</sup> for the rationalized mix ratio at 28 days curing based on the minimum compressive strength required, this study arrives at the conclusion that the equal volumes of sand and gravel mix ratio of 350 kg/m<sup>3</sup> of cement: 600 liters of sand: 600 liters of gravel mix ratio can be adopted as a conventional concrete mix ratio for gravel size 5/15 + 15/25.展开更多
Belly fat has long been thought to be particularly bad for your heart, but now, a new study adds more evidence to the idea that it may also be bad for your brain. The study, from the United Kingdom, found that people ...Belly fat has long been thought to be particularly bad for your heart, but now, a new study adds more evidence to the idea that it may also be bad for your brain. The study, from the United Kingdom, found that people who were obese and had a high waist-to-hip ratio (a measure of belly fat) had slightly lower brain volumes, on average, compared with people who were a healthy weight. Specifically, belly fat was linked with lower volumes of gray matter, the brain tissue that contains nerve cells.展开更多
Background This study aimed to investigate the relationship between overall obesity,central obesity and brain volumes,as well as to determine the extent to which cardiometabolic and inflammatory measures act as mediat...Background This study aimed to investigate the relationship between overall obesity,central obesity and brain volumes,as well as to determine the extent to which cardiometabolic and inflammatory measures act as mediators in the association between body mass index(BMI),waist-hip ratio(WHR)and brain volumes.Methods In the context of counterfactual framework,mediation analysis was used to explore the potential mediation in which cardiometabolic and inflammatory measures may mediate the relationship between BMI,WHR,and brain volumes.Results Among 2413 community-dwelling participants,those with high BMI or WHR levels experienced an approximately brain ageing of 4 years.Especially,individuals with high WHR or BMI under the age of 65 exhibited white matter hyperintensity volume(WMHV)differences equivalent to around 5 years of ageing.Conversely,in the high-level WHR population over the age of 65,premature brain ageing in gray matter volume(GMV)exceeded 4.5 years.For GMV,more than 45%of the observed effect of WHR was mediated by glycaemic metabolism indicators.This proportion increases to 78.70%when blood pressure,triglyceride,leucocyte count,and neutrophil count are jointly considered with glycaemic metabolism indicators.Regarding WHR and BMI’s association with WMHV,cardiometabolic and inflammatory indicators,along with high-density lipoprotein cholesterol,mediated 35.50%and 20.20%of the respective effects.Conclusions Overall obesity and central obesity were associated with lower GMV and higher WMHV,a process that is partially mediated by the presence of cardiometabolic and inflammatory measures.展开更多
The monumental second edition Petroleum Geology of China has been published by the Petroleum Industry Press.This definitive work was compiled under the leadership of Academician Zhai Guangming,a preeminent authority i...The monumental second edition Petroleum Geology of China has been published by the Petroleum Industry Press.This definitive work was compiled under the leadership of Academician Zhai Guangming,a preeminent authority in petroleum exploration.As the culmination of eight years of dedicated effort by over a thousand experts and scholars,this monumental publication comprises 25 volumes(bound in 32 books).展开更多
We prove that for a smooth convex body K⊂ℝ^(d),d≥2,with positive Gauss curvature,its homothety with a certain associated convex body implies that K is either a ball or an ellipsoid,depending on the associated body co...We prove that for a smooth convex body K⊂ℝ^(d),d≥2,with positive Gauss curvature,its homothety with a certain associated convex body implies that K is either a ball or an ellipsoid,depending on the associated body considered.展开更多
The rapid development of artificial intelligence(AI),machine learning(ML),and deep learning(DL)in recent years has transformed many sectors.A fundamental shift has occurred in approaches to solving complex problems an...The rapid development of artificial intelligence(AI),machine learning(ML),and deep learning(DL)in recent years has transformed many sectors.A fundamental shift has occurred in approaches to solving complex problems and making decisions in many different fields.These advanced technologies have enabled significant breakthroughs in sectors including entertainment,finance,transportation,and healthcare.AI systems,which can analyze vast volumes of data,have significantly driven efficiency and innovation.With remarkable accuracy,patterns can be identified and predictions generated,improving decision-making processes and facilitating the development of more intelligent solutions.The increasing adoption of these technologies by organizations has expanded the potential for AI to change processes and improve results.展开更多
By using the Taylor expansions of the solutions of Jacobi equations, we obtain the complete formulas for the volumes of tubes about curves in a Riemanuian manifold. This unifies the known results and simplifies the co...By using the Taylor expansions of the solutions of Jacobi equations, we obtain the complete formulas for the volumes of tubes about curves in a Riemanuian manifold. This unifies the known results and simplifies the computations involved in this direction. In the special case of surfaces, we also obtain the corresponding complete formulas which generalize the known results.展开更多
The relation between cell-edges or unit-cell volumes of isostructural compounds and theionic radii has wide applications in crystal chemistry. The authors have proved: (1) For a series of multiple isostructural compou...The relation between cell-edges or unit-cell volumes of isostructural compounds and theionic radii has wide applications in crystal chemistry. The authors have proved: (1) For a series of multiple isostructural compounds such as A_mB_n…X_p, when the anionand other cations are fixed, there exists the following relation between the unit-cell volume Vand the radius r_A of a certain cation such as A: V = (a + br_A)(r_X + r_A)~3 (a and b are constants). (2) For binary isostructural compounds A_mX_p, the above relation is reduced to V = k(r_X + r_A)~3 (k is a constant). (3) For binary isostructural compounds the relation between V and r_A^3 is approximatelylinear, and for multiple compounds, it is often curvilinear but still approximately linear whenthe variation of r_A is slight. As another approximation, a linear relation also exists betweenV and r_A for isostructural compounds. (4) The relation of ce1l-edge a vs. r_A is linear for binary isostructural compounds. Butno such a good linear relation exists for multiple isostructural compounds.展开更多
The effect of sublingual administration and intravenous drip of nitroglycerin (SLNTG and IVNTG) on left ventricular volumes (LVVs) were studied and systolic function was quantitatively assessed with two-dimensional ec...The effect of sublingual administration and intravenous drip of nitroglycerin (SLNTG and IVNTG) on left ventricular volumes (LVVs) were studied and systolic function was quantitatively assessed with two-dimensional echocardiography (2DE) in 28 patients with myocardial infarction (MI), including 13 cases without heart failure (MI-NHF) in one group and 15 with heart failure (MI-HF) in another. The results showed that after SLNTG and IVNTG in both groups the heart rate (HR) increased significantly (P< 0.05-0.001); the systolic blood pressure (SBP) decreased significantly (P< 0.05-0.001); the diastolic blood pressure (DBP) was not significantly changed (all P>0.05); the left ventricular end-diastolic and end-systolic volumes (EDV and ESV) both significantly reduced [EDV: decreased by 5.8-11.6% (-13.2-19.0 ml), P< 0.05-0.001; ESV: decreased by 9.6-16.6% (-8.6-17.3 ml), P< 0.05-0.001)1; the left ventricular ejection fraction (LVEF) all significantly elevated (increased by 6.6%-9.4% (3.2%-3.4%), P < 0.05-0.001] except in MI-NHF group after IVNTG; the segmental EF of normal and hypokinetic segments also significantly increased (P<0.05-0.001). The results suggest that NTG could beneficially reduce left ventricular EDV and ESV; and improve or strengthen its global and segmental systolic function in MI patients, particularly noticeable in patients with heart failure.展开更多
文摘In stock markets,trading volumes serve as a crucial variable,acting as a measure for a security’s liquidity level.To evaluate liquidity risk exposure,we examine the process of volume drawdown and measures of crash-recovery within fluctuating time frames.These moving time windows shield our financial indicators from being affected by the massive transaction volume,a characteristic of the opening and closing of stock markets.The empirical study is conducted on the high-frequency financial volumes of Tesla,Netflix,and Apple,spanning from April to September 2022.First,we model the financial volume time series for each stock using a semi-Markov model,known as the weighted-indexed semi-Markov chain(WISMC)model.Second,we calculate both real and synthetic drawdown-based risk indicators for comparison purposes.The findings reveal that our risk measures possess statistically different distributions,contingent on the selected time windows.On a global scale,for all assets,financial risk indicators calculated on data derived from the WISMC model closely align with the real ones in terms of Kullback-Leibler divergence.
文摘The authors establish some inequalities about the dual mixed volumes of star bodies in Rn. These inequalities are the analogue in the Brunn-Minkowski theory of the inequalities of Marcus-Lopes and Bergstrom about symmetric functions of positive reals.
基金Supported by National Natural Science Foundation of China under Grant No.10801027Fok Ying Tong Education Foundation under Grant No.121003
文摘In this paper,we define lower-dimensional volumes of spin manifolds with boundary.We compute thelower-dimensional volume Vol^((2,2)) for 5-dimensional and 6-dimensional spin manifolds with boundary and we also getthe Kastler-Kalau-Walze type theorem in this case.
基金The study was funded by the Zhejiang Provincial Traditional Chinese Medicine Administration of China(approval number 2011ZB083)the Quality of Nursing Practice Project of the Chinese Medical Association.
文摘Objective:To study the effects of prolonging small feeding volumes early in life on the incidence of necrotizing enterocolitis(NEC)in very low birth weight(VLBW)preterm infants.Methods:A total of 128 VLBW infants who could not be breastfed were assigned into the experimental group(63 cases)and the control group(65 cases)using a random number table.The experiment group was fed 12 mL/(kg·d)on day 1 which was increased to 24 mL/(kg·d)for the first 10 study days.The control group was fed 12 mL/(kg·d)for the first 14e48 hours.Then,the feeding volume increased by 24-36 mL/(kg·d)up to 140e160 mL/(kg·d)and maintained until the 10th day after birth.The incidence of feeding intolerance and NEC,duration of hospitalization,time to full enteral feedings,incidence of intrahepatic cholestasis,and the levels of gastrin and motilin in serum were assessed.Results:The incidence of feeding intolerance was significantly lower in the experimental group compared with the control group(15.87% vs.33.84%).There was a significant reduction in the incidence of NEC between the experimental and control groups(7.9% vs.16% in the control group).Conclusion:A protocol that prolongs small feeding volumes early in life can reduce the incidence and severity of NEC,but still warrants further study.
文摘The present work is focusing on the synthesization and physico-chemical properties of Jatropha curcas biodiesel with diesel and alcohols.The densities of binary diesel(2)+1-alkanols(C_(3) or C_(4))(3)and ternary Jatropha curcas biodiesel(1)+diesel(2)+1-alkanols(C_(3)or C_(4))(3)blends have been reported over full range of composition at temperatures within range 288.15 to 313.15 K.Also densities of Jatropha curcas biodiesel(1)+diesel or 1-alkanols(C_(3) or C_(4))(2)blends have been measured at 313.15 K.Excess molar volumes,V^E,V^E_(123)of binary and ternary blends were calculated from the measured data and the derived properties were correlated to composition using Redlich-Kister equation.A reasonable agreement was found between the measured and estimated values.Further,densities and excess molar volumes data were reasoned to discuss molecular interactions taking into consideration effect of composition and temperature.
文摘Previous studies have reported decreased cerebral volume as a result of smoking. However, little is known about accompanying changes in ventricular volume for healthy subjects who smoke, although ventricular volume is increased in patients with multiple sclerosis who smoke. The present study analyzed whether cerebral volume decreased with smoking through the use of magnetic resonance imaging. In addition, accompanying changes in ventricular volume that resulted from decreased cerebral volume and smoking were analyzed in healthy subjects. When multivariate analysis of covariance was performed by integrating the 2 age groups, aged 20-28 years and 40-49 years, with statistical significance, results showed that cerebral volume of smokers was smaller and ventricular volume was greater compared with the non-smokers. These findings suggest that ventricular volume changes could be utilized to characterize the effects of smoking.
文摘AIM:To compare hippocampus and amygdala volumes of patients with vaginismus with those of healthy control subjects.METHODS:Magnetic resonance imaging was performed on ten patients with vaginismus and ten control subjects matched for age and gender.Volumes of the hippocampus and amygdala were blindly measured.RESULTS:We found that the mean right amygdala volume of patients with vaginismus were smaller than that of the healthy controls.With regard to hippocampus volumes,the mean left and right hippocampus volumes were smaller than those of the healthy controls.CONCLUSION:Our present findings suggest that there have been hippocampus and amygdala structural abnormalities in patients with vaginismus.These changes provide the notion that vaginismus may be a fear-related condition.
文摘This paper applies both the neural network and adaptive neuro-fuzzy inference system for forecasting short-term chaotic traffic volumes and compares the results. The architecture of the neural network consists of the input vector, one hidden layer and output layer. Bayesian regularization is employed to obtain the effective number of neurons in the hidden layer. The input variables and target of the adaptive neuro-fuzzy inference system are the same as those of the neural network. The data clustering technique is used to group data points so that the membership functions will be more tailored to the input data, which in turn greatly reduces the number of fuzzy rules. Numerical results indicate that these two models have almost the same accuracy, while the adaptive neuro-fuzzy inference system takes more time to train. It is also shown that although the effective number of neurons in the hidden layer is less than half the number of the input elements, the neural network can have satisfactory performance.
文摘Purpose: The aim of the present study was to evaluate the diagnostic accuracy for quantification of left ventricular (LV) volumes and LV ejection fraction (LVEF) with current echocardiographic methods of planimetry for analysis of LV remodeling after myocardial infarction in daily clinical routine. Methods: 26 patients were investigated directly after interventional therapy at hospital pre-discharge and at 6 month follow-up. Standardized 2D transthoracic native and contrast echocardiography were performed in all patients. Due to methodological aspects the results of LV volumes and LVEF using native echocardiography were compared to the results of LV opacification (LVO) imaging for analysis in mono-, bi- and triplane data sets using the Simpson’s rule. In addition corresponding multidimensional data sets were analyzed. Results: The assessment of LV volumes and LVEF is more accurate with contrast echocardiography. The comparison of LV volumes and LVEF shows significant increases using contrast echocardiography (p < 0.001). Larger left ventricular end-diastolic volumes (LVEDV) are measured at follow up (p < 0.05). Significant differences (p < 0.001) are found for the determination of LVEDV and LVEF relating to apical mono-, bi-, tri- and multiplane data sets. Standard deviations of the triplane approach, however, are significantly lower than using other modalities. Conclusion: Depending on the localization of the myocardial infarction LV volumes and LVEF are less reliably evaluated using the mono- or biplane approach. According to standardization and simultaneous acquisition of all LV wall segments the triplane approach is currently the best approach to determine LV systolic function. In addition, contrast echocardiography is indicated to improve endocardial border delineation in patients using the triplane or multiplane approach. To our knowledge the present study is the first systematic evaluation of all current possibilities for determination of LV volumes and LVEF by native and contrast echocardiography.
文摘The control volume method gives the forces which act on the system, but not necessarily the wall pressure of the system. The author has made an attempt to develop a control volume method which makes it possible to obtain the wall pressure of the control volume. The 2-D inviscid incompressible steady duct flow is considered. The conservation equations in integral form are discretized for a control volume. The circulation along the control surface is expressed as a nonlinear function of the vertical velocity component at the inlet and is set equal to zero for the inviscid flow. The equation is solved by the Newton method, and the other aerodynamic properties can be obtained. The calculated results have been compared to the experiment and the agreement has been found fairly satisfactory.
文摘In recent years, the rationalization of concrete mix ratios which batches equal volumes of sand and gravel in building projects has been gaining grounds in the Cameroon construction industry. The main objective of this study is therefore to investigate if the concrete produced with rationalized mix ratio can be adopted as conventional mix ratio in terms of minimum required compression strength of concrete for buildings. Specifically this work compared the conventional mix ratio of 350 kg of cement: 400 liters of sand: 800 liters of gravel for a cubic meter and the rationalized batch of 350 kg of cement: 600 liters of sand: 600 liters of 5/15 gravel, 15/25 gravel and a combination of 5/15 + 15/25 gravel. Average compressive tests’results for both the conventional and the rationalized mix ratios were found to meet the minimum compressive strength of 65% at 7 days, 90% at 14 days and 99% at 28 days for gravel size combination 5/15 + 15/25. Single size gravel of 5/15 and 15/25 did not meet the minimum required compressive strength of 20 N/mm<sup>2</sup> for the rationalized mix ratio at 28 days curing based on the minimum compressive strength required, this study arrives at the conclusion that the equal volumes of sand and gravel mix ratio of 350 kg/m<sup>3</sup> of cement: 600 liters of sand: 600 liters of gravel mix ratio can be adopted as a conventional concrete mix ratio for gravel size 5/15 + 15/25.
文摘Belly fat has long been thought to be particularly bad for your heart, but now, a new study adds more evidence to the idea that it may also be bad for your brain. The study, from the United Kingdom, found that people who were obese and had a high waist-to-hip ratio (a measure of belly fat) had slightly lower brain volumes, on average, compared with people who were a healthy weight. Specifically, belly fat was linked with lower volumes of gray matter, the brain tissue that contains nerve cells.
基金supported by National Key R&D Programme of China(No.2022YFC3602500,2022YFC3602505)National Natural Science Foundation of China(81971091)+3 种基金Outstanding Young Talents Project of Capital Medical University(A2105)Capital’s Funds for Health Improvement and Research(2020-1-2041)Key Science&Technologies R&D Programme of Lishui City(2019ZDYF18)Zhejiang Provincial Programme for the Cultivation of High-level Innovative Health talents and AstraZeneca Investment(China)Co.,Ltd.
文摘Background This study aimed to investigate the relationship between overall obesity,central obesity and brain volumes,as well as to determine the extent to which cardiometabolic and inflammatory measures act as mediators in the association between body mass index(BMI),waist-hip ratio(WHR)and brain volumes.Methods In the context of counterfactual framework,mediation analysis was used to explore the potential mediation in which cardiometabolic and inflammatory measures may mediate the relationship between BMI,WHR,and brain volumes.Results Among 2413 community-dwelling participants,those with high BMI or WHR levels experienced an approximately brain ageing of 4 years.Especially,individuals with high WHR or BMI under the age of 65 exhibited white matter hyperintensity volume(WMHV)differences equivalent to around 5 years of ageing.Conversely,in the high-level WHR population over the age of 65,premature brain ageing in gray matter volume(GMV)exceeded 4.5 years.For GMV,more than 45%of the observed effect of WHR was mediated by glycaemic metabolism indicators.This proportion increases to 78.70%when blood pressure,triglyceride,leucocyte count,and neutrophil count are jointly considered with glycaemic metabolism indicators.Regarding WHR and BMI’s association with WMHV,cardiometabolic and inflammatory indicators,along with high-density lipoprotein cholesterol,mediated 35.50%and 20.20%of the respective effects.Conclusions Overall obesity and central obesity were associated with lower GMV and higher WMHV,a process that is partially mediated by the presence of cardiometabolic and inflammatory measures.
文摘The monumental second edition Petroleum Geology of China has been published by the Petroleum Industry Press.This definitive work was compiled under the leadership of Academician Zhai Guangming,a preeminent authority in petroleum exploration.As the culmination of eight years of dedicated effort by over a thousand experts and scholars,this monumental publication comprises 25 volumes(bound in 32 books).
文摘We prove that for a smooth convex body K⊂ℝ^(d),d≥2,with positive Gauss curvature,its homothety with a certain associated convex body implies that K is either a ball or an ellipsoid,depending on the associated body considered.
基金funded by the Research,Development,and Innovation Authority(RDIA),Kingdom of Saudi Arabia,with grant number 13382-PSU-2023-PSNU-R-3-1-EIsupported by the Automated Systems and Computing Lab(ASCL),Prince Sultan University,Riyadh,Saudi Arabia.
文摘The rapid development of artificial intelligence(AI),machine learning(ML),and deep learning(DL)in recent years has transformed many sectors.A fundamental shift has occurred in approaches to solving complex problems and making decisions in many different fields.These advanced technologies have enabled significant breakthroughs in sectors including entertainment,finance,transportation,and healthcare.AI systems,which can analyze vast volumes of data,have significantly driven efficiency and innovation.With remarkable accuracy,patterns can be identified and predictions generated,improving decision-making processes and facilitating the development of more intelligent solutions.The increasing adoption of these technologies by organizations has expanded the potential for AI to change processes and improve results.
文摘By using the Taylor expansions of the solutions of Jacobi equations, we obtain the complete formulas for the volumes of tubes about curves in a Riemanuian manifold. This unifies the known results and simplifies the computations involved in this direction. In the special case of surfaces, we also obtain the corresponding complete formulas which generalize the known results.
文摘The relation between cell-edges or unit-cell volumes of isostructural compounds and theionic radii has wide applications in crystal chemistry. The authors have proved: (1) For a series of multiple isostructural compounds such as A_mB_n…X_p, when the anionand other cations are fixed, there exists the following relation between the unit-cell volume Vand the radius r_A of a certain cation such as A: V = (a + br_A)(r_X + r_A)~3 (a and b are constants). (2) For binary isostructural compounds A_mX_p, the above relation is reduced to V = k(r_X + r_A)~3 (k is a constant). (3) For binary isostructural compounds the relation between V and r_A^3 is approximatelylinear, and for multiple compounds, it is often curvilinear but still approximately linear whenthe variation of r_A is slight. As another approximation, a linear relation also exists betweenV and r_A for isostructural compounds. (4) The relation of ce1l-edge a vs. r_A is linear for binary isostructural compounds. Butno such a good linear relation exists for multiple isostructural compounds.
文摘The effect of sublingual administration and intravenous drip of nitroglycerin (SLNTG and IVNTG) on left ventricular volumes (LVVs) were studied and systolic function was quantitatively assessed with two-dimensional echocardiography (2DE) in 28 patients with myocardial infarction (MI), including 13 cases without heart failure (MI-NHF) in one group and 15 with heart failure (MI-HF) in another. The results showed that after SLNTG and IVNTG in both groups the heart rate (HR) increased significantly (P< 0.05-0.001); the systolic blood pressure (SBP) decreased significantly (P< 0.05-0.001); the diastolic blood pressure (DBP) was not significantly changed (all P>0.05); the left ventricular end-diastolic and end-systolic volumes (EDV and ESV) both significantly reduced [EDV: decreased by 5.8-11.6% (-13.2-19.0 ml), P< 0.05-0.001; ESV: decreased by 9.6-16.6% (-8.6-17.3 ml), P< 0.05-0.001)1; the left ventricular ejection fraction (LVEF) all significantly elevated (increased by 6.6%-9.4% (3.2%-3.4%), P < 0.05-0.001] except in MI-NHF group after IVNTG; the segmental EF of normal and hypokinetic segments also significantly increased (P<0.05-0.001). The results suggest that NTG could beneficially reduce left ventricular EDV and ESV; and improve or strengthen its global and segmental systolic function in MI patients, particularly noticeable in patients with heart failure.
