Physician well-being is vital to delivering high-quality emergency care.A supported and healthy emergency medicine workforce leads to better patient outcomes,fewer medical errors,and greater job satisfaction and staff...Physician well-being is vital to delivering high-quality emergency care.A supported and healthy emergency medicine workforce leads to better patient outcomes,fewer medical errors,and greater job satisfaction and staff retention.[1,2]Emergency physicians(EPs)face unique pressures,including shift work,high patient volumes and acuities,overcrowding,and systemic inefficiencies that escalate their risk of burnout.As a result,EPs have reported the highest rates of burnout among physician specialties.展开更多
A deep-water harbour in Hainan has emerged as a pivotal gateway to regions around the world Located on the northwest tip of Hainan Island,Yangpu Port is bustling with activity,with towering gantry cranes frantically l...A deep-water harbour in Hainan has emerged as a pivotal gateway to regions around the world Located on the northwest tip of Hainan Island,Yangpu Port is bustling with activity,with towering gantry cranes frantically loading containers on and off large cargo vessels.Cargo volumes here have surged as a result of a slew of special customs policies that went into force in December 2025.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
The effects of fly ash and MgO-type expansive agent on the shrinkage and expan-sive strain of concrete with high magnesia cement were investigated. The results show that high volumes of fly ash may reduce the shrinkag...The effects of fly ash and MgO-type expansive agent on the shrinkage and expan-sive strain of concrete with high magnesia cement were investigated. The results show that high volumes of fly ash may reduce the shrinkage strain of concrete and inhibit the expansive strain of concrete with MgO-type expansive agent, but can not eliminate the shrinkage of concrete. MgO-type expansive agent may produce expansive strain and compensate the shrinkage strain of concrete, re-lieve the cracking risk, but the hydration product of magnesia tends to get together in paste and pro-duce expansive cracking of concrete with high magnesia content according to SEM observation.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
Let Bp^n={x∈R^b｜‖x‖p≤1} be the unit ball of p norm in the n-dimensional normed space εp＆n.The formula for the volume of Bp^n was obtained and its asymptotic properties were found out as n→∞and p→∞.
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
AIM To define regional grey-matter abnormalities in schizophrenia patients with poor insight(Insight-),relative to patients with preserved clinical insight(Insight+),and healthy controls.METHODS Forty stable schizophr...AIM To define regional grey-matter abnormalities in schizophrenia patients with poor insight(Insight-),relative to patients with preserved clinical insight(Insight+),and healthy controls.METHODS Forty stable schizophrenia outpatients(20 Insight-and 20 Insight+) and 20 healthy controls underwent whole brain magnetic resonance imaging(MRI).Insight in all patients was assessed using the Birchwood Insight Scale(BIS;a self-report measure).The two patient groups were preselected to match on most clinical and demographic parameters but,by design,they had markedly distinct BIS scores.Voxel-based morphometry employed in SPM8 was used to examine group differences in grey matter volumes across the whole brain.RESULTS The three participant groups were comparable in age [F(2,57) = 0.34,P = 0.71] and the patient groups did not differ in age at illness onset [t(38) = 0.87,P = 0.39].Insight-and Insight+ patient groups also did not differ in symptoms on the Positive and Negative Syndromes scale(PANSS):Positive symptoms [t(38) = 0.58,P = 0.57],negative symptoms [t(38) = 0.61,P = 0.55],general psychopathology [t(38) = 1.30,P = 0.20] and total PANSS scores [t(38) = 0.21,P = 0.84].The two patient groups,as expected,varied significantly in the level of BIS-assessed insight [t(38) = 12.11,P < 0.001].MRI results revealed lower fronto-temporal,parahippocampal,occipital and cerebellar grey matter volumes in Insightpatients,relative to Insight+ patients and healthy controls(for all clusters,family-wise error corrected P < 0.05).Insight+ patient and healthy controls did not differ significantly(P > 0.20) from each other.CONCLUSION Our findings demonstrate a clear association between poor clinical insight and smaller fronto-temporal,occipital and cerebellar grey matter volumes in stable long-term schizophrenia patients.展开更多
Segmenting brain tumors in Magnetic Resonance Imaging(MRI)volumes is challenging due to their diffuse and irregular shapes.Recently,2D and 3D deep neural networks have become famous for medical image segmentation beca...Segmenting brain tumors in Magnetic Resonance Imaging(MRI)volumes is challenging due to their diffuse and irregular shapes.Recently,2D and 3D deep neural networks have become famous for medical image segmentation because of the availability of labelled datasets.However,3D networks can be computationally expensive and require significant training resources.This research proposes a 3D deep learning model for brain tumor segmentation that uses lightweight feature extraction modules to improve performance without compromising contextual information or accuracy.The proposed model,called Hybrid Attention-Based Residual Unet(HA-RUnet),is based on the Unet architecture and utilizes residual blocks to extract low-and high-level features from MRI volumes.Attention and Squeeze-Excitation(SE)modules are also integrated at different levels to learn attention-aware features adaptively within local and global receptive fields.The proposed model was trained on the BraTS-2020 dataset and achieved a dice score of 0.867,0.813,and 0.787,as well as a sensitivity of 0.93,0.88,and 0.83 for Whole Tumor,Tumor Core,and Enhancing Tumor,on test dataset respectively.Experimental results show that the proposed HA-RUnet model outperforms the ResUnet and AResUnet base models while having a smaller number of parameters than other state-of-the-art models.Overall,the proposed HA-RUnet model can improve brain tumor segmentation accuracy and facilitate appropriate diagnosis and treatment planning for medical practitioners.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
Currently, most developing countries have not set up municipal solid waste management systems with a view of recovering energy from waste or reducing greenhouse gas emissions. In this article, we have studied the poss...Currently, most developing countries have not set up municipal solid waste management systems with a view of recovering energy from waste or reducing greenhouse gas emissions. In this article, we have studied the possible effects of introducing three energy recovery processes either as a single or combination approach, refuse derived fuel production,incineration and waste power generation, and methane gas recovery from landfill and power generation in Ulaanbaatar, Mongolia, as a case study. We concluded that incineration process is the most suitable as first introduction of energy recovery. To operate it efficiently,3Rs strategies need to be promoted. And then, RDF production which is made of waste papers and plastics in high level of sorting may be considered as the second step of energy recovery.However, safety control and marketability of RDF will be required at that moment.展开更多
Background Atrial fibrillation （AF） causes a continuum of atrial anatomical remodeling. Methods Using a library of perfusion-fixed human hearts, specimens with AF were compared to controls. During this preliminary a...Background Atrial fibrillation （AF） causes a continuum of atrial anatomical remodeling. Methods Using a library of perfusion-fixed human hearts, specimens with AF were compared to controls. During this preliminary assessment study, direct measurements were taken of atrial volume, pulmonary vein （PV） circumference, and left atrial （LA） wall thicknesses. Results Hearts with AF typically had larger atrial volumes, as well as a much larger variation in volume compared to controls （range of 59.6-227.1 mL in AF hearts compared to 65.1-115.9 mL in controls）. For all hearts, right PVs were larger than left PVs （mean： 171.4 ± 84.6 mm^2 for right and 1182 ± 50.1 mm^2 for left, P 〈 0.005）. LA wall thicknesses ranged from 0.7 mm to 3.1 mm for both AF and control hearts. Conclusions Hearts with AF had a large range of sizes which is consistent with the progression of atrial remodeling during AF. The large range of thicknesses will influence the amount of energy needed to create transmural lesions during ablation procedures.展开更多
Two-dimensional transient laminar natural convection in a square cavity containing a porous medium and inclined at an angle of 30°is investigated numerically.The vertical walls are differentially heated,and the h...Two-dimensional transient laminar natural convection in a square cavity containing a porous medium and inclined at an angle of 30°is investigated numerically.The vertical walls are differentially heated,and the horizontal walls are adiabatic.The effect of Rayleigh number on heat transfer and on the road to chaos is analyzed.The natural heat transfer and the Darcy Brinkman equations are solved by using a finite volume method and a Tri Diagonal Matrix Algorithm(TDMA).The results are obtained for a porosity equal to 0.45,a Darcy number and a Prandtl respectively equal to 10^(-3)and 0.71;they are analyzed in terms of streamlines,isotherms,phase portrait,attractors,and spectra amplitude as a function of the Rayleigh number.It is found that,as Rayleigh number increases,the natural convection changes from a steady state to a time-periodic state and finally to a chaotic condition.展开更多
AIM To investigate changes in polyp detection throughout fellowship training, and estimate colonoscopy volume required to achieve the adenoma detection rate(ADRs) and polyp detection rate(PDRs) of attending gastroente...AIM To investigate changes in polyp detection throughout fellowship training, and estimate colonoscopy volume required to achieve the adenoma detection rate(ADRs) and polyp detection rate(PDRs) of attending gastroenterologists.METHODS We reviewed colonoscopies from July 1, 2009 to June 30, 2014. Fellows' procedural logs were used to retrieve colonoscopy procedural volumes, and these were treated as the time variable. Findings from screening colonoscopies were used to calculate colonoscopy outcomes for each fellow for the prior 50 colonoscopies at each time point. ADR and PDR were plotted against colonoscopy procedural volumes to produce individual longitudinal graphs. Repeated measures linear mixed effects models were used to study the change of ADR and PDR with increasing procedural volume.RESULTS During the study period, 12 fellows completed full three years of training and were included in the analysis. The average ADR and PDR were, respectively, 31.5% and 41.9% for all fellows, and 28.9% and 38.2% for attendings alone. There was a statistically significant increase in ADR with increasing procedural volume(1.8%/100 colonoscopies, P = 0.002). Similarly, PDR increased 2.8%/100 colonoscopies(P = 0.0001), while there was no significant change in advanced ADR(0.04%/100 colonoscopies, P = 0.92). The ADR increase was limited to the right side of the colon, while the PDR increased in both the right and left colon. The adenoma per colon and polyp per colon also increased throughout training. Fellows reached the attendings' ADR and PDR after 265 and 292 colonoscopies, respectively.CONCLUSION We found that the ADR and PDR increase with increasing colonoscopy volume throughout fellowship. Our findings support recent recommendations of ≥ 275 colonoscopies for colonoscopy credentialing.展开更多
Overweight and obesity are highly prevalent in developed and developing countries among children and adolescents. During the last two decades, it became evident that excess weight is adversely related to respiratory h...Overweight and obesity are highly prevalent in developed and developing countries among children and adolescents. During the last two decades, it became evident that excess weight is adversely related to respiratory health in childhood and adolescence mainly in terms of asthma occurrence. Additionally, there is a mounting body of evidence that overweight/obesity may also affect lung function in non-asthmatic subjects. The aim of this review was to present and discuss the studies that investigated this issue in non-asthmatic children and adolescents. Only a few studies have evaluated the impact of excess weight on static volumes and their results point towards an inverse relationship between overweight/obesity and functional residual capacity. More studies have been conducted on the impact of excess weight on dynamic lung volumes with inconsistent, however, results. Nevertheless, a relatively consistent finding was that the ratio of forced expiratory volume in 1 s/forced vital capacity was significantly lower among overweight/obese children compared to their counterparts with normal weight. The underlying mechanisms of these observations have not been adequately elucidated but it is believed to result from complex interaction of mechanical, developmental, and metabolic causes. There is a need for more welldesigned studies in order to clarify the impact of excess weight on lung function in non-asthmatic subjects, as well as to explore the contribution of factors such as duration and degree of obesity, and fat distribution. Despite the absence of conclusive data, there are stillconvincing evidence to be communicated to the children and their families as part of the arguments to encourage them to adopt a healthier lifestyle.展开更多
Densities(ρ) and dynamic viscosities(η) for three binary mixtures of n-decane with 1-pentanol,1-hexanol and1-heptanol are presented at temperatures from 293.15 to 363.15 K and atmospheric pressure over the entire co...Densities(ρ) and dynamic viscosities(η) for three binary mixtures of n-decane with 1-pentanol,1-hexanol and1-heptanol are presented at temperatures from 293.15 to 363.15 K and atmospheric pressure over the entire composition range.The density and viscosity are measured using a vibrating tube densimeter and a cylindrical Couette type rotating viscometer,respectively.Excess molar volumes(V^E),viscosity deviations(△η) and excess Gibbs energy of activation of viscous flow(△G^(*E)) are calculated from the experimental measurements.Intermolecular and structural interactions are indicated by the sign and magnitude of these properties.Partial molar volumes and infinity dilution molar partial volumes are also calculated for each binary system.These results are correlated using Redlich-Kister type equations.展开更多
The results stemming from the calculation of heat transfer in torch furnaces by the laws, relating to radiation from solid surfaces and gas volumes are analyzed. The article presents the laws for radiation from gas vo...The results stemming from the calculation of heat transfer in torch furnaces by the laws, relating to radiation from solid surfaces and gas volumes are analyzed. The article presents the laws for radiation from gas volumes and the procedure for calculating heat transfer in torch furnaces, fire boxes, and combustion chambers, elaborated on their basis. The example of heat transfer calculation in a torch furnace is given, and it is significantly non-uniform in nature. Non-uniformity of heat flux distribution on heating surfaces is given. According to the results of calculations, a new furnace is designed to decrease the non-uniformity of ingot heating, fuel rate, and increase the furnace capacity. The calculation results of the distribution of heat fluxes on the heating surfaces are given in changing torch geometric dimensions. These results are confirmed by experimental studies.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
文摘Physician well-being is vital to delivering high-quality emergency care.A supported and healthy emergency medicine workforce leads to better patient outcomes,fewer medical errors,and greater job satisfaction and staff retention.[1,2]Emergency physicians(EPs)face unique pressures,including shift work,high patient volumes and acuities,overcrowding,and systemic inefficiencies that escalate their risk of burnout.As a result,EPs have reported the highest rates of burnout among physician specialties.
文摘A deep-water harbour in Hainan has emerged as a pivotal gateway to regions around the world Located on the northwest tip of Hainan Island,Yangpu Port is bustling with activity,with towering gantry cranes frantically loading containers on and off large cargo vessels.Cargo volumes here have surged as a result of a slew of special customs policies that went into force in December 2025.
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.
基金Funded by the National Natural Science Foundation of China (No. 60672166)the Bureau of Water Resources & Hydropower Research of China (No. SPKJ006-13-01-01)
文摘The effects of fly ash and MgO-type expansive agent on the shrinkage and expan-sive strain of concrete with high magnesia cement were investigated. The results show that high volumes of fly ash may reduce the shrinkage strain of concrete and inhibit the expansive strain of concrete with MgO-type expansive agent, but can not eliminate the shrinkage of concrete. MgO-type expansive agent may produce expansive strain and compensate the shrinkage strain of concrete, re-lieve the cracking risk, but the hydration product of magnesia tends to get together in paste and pro-duce expansive cracking of concrete with high magnesia content according to SEM observation.
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Project supported by the Science Foundation of Shanghai Municipal Commission of Education (Grant No.24667).
文摘Let Bp^n={x∈R^b｜‖x‖p≤1} be the unit ball of p norm in the n-dimensional normed space εp＆n.The formula for the volume of Bp^n was obtained and its asymptotic properties were found out as n→∞and p→∞.
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Supported by The Wellcome Trust,United Kingdom and was carried out as part of the first author’s PhD research under Professor Veena Kumari and Dr Dominic ffytche’s supervision,Nos.067427 and 072298Professor Kumari is part funded by the Biomedical Research Centre for Mental Health at the Institute of Psychiatry,Psychology and Neuroscience King’s College London,and the South London and Maudsley NHS Foundation Trust,United Kingdom(to Kumari V)
文摘AIM To define regional grey-matter abnormalities in schizophrenia patients with poor insight(Insight-),relative to patients with preserved clinical insight(Insight+),and healthy controls.METHODS Forty stable schizophrenia outpatients(20 Insight-and 20 Insight+) and 20 healthy controls underwent whole brain magnetic resonance imaging(MRI).Insight in all patients was assessed using the Birchwood Insight Scale(BIS;a self-report measure).The two patient groups were preselected to match on most clinical and demographic parameters but,by design,they had markedly distinct BIS scores.Voxel-based morphometry employed in SPM8 was used to examine group differences in grey matter volumes across the whole brain.RESULTS The three participant groups were comparable in age [F(2,57) = 0.34,P = 0.71] and the patient groups did not differ in age at illness onset [t(38) = 0.87,P = 0.39].Insight-and Insight+ patient groups also did not differ in symptoms on the Positive and Negative Syndromes scale(PANSS):Positive symptoms [t(38) = 0.58,P = 0.57],negative symptoms [t(38) = 0.61,P = 0.55],general psychopathology [t(38) = 1.30,P = 0.20] and total PANSS scores [t(38) = 0.21,P = 0.84].The two patient groups,as expected,varied significantly in the level of BIS-assessed insight [t(38) = 12.11,P < 0.001].MRI results revealed lower fronto-temporal,parahippocampal,occipital and cerebellar grey matter volumes in Insightpatients,relative to Insight+ patients and healthy controls(for all clusters,family-wise error corrected P < 0.05).Insight+ patient and healthy controls did not differ significantly(P > 0.20) from each other.CONCLUSION Our findings demonstrate a clear association between poor clinical insight and smaller fronto-temporal,occipital and cerebellar grey matter volumes in stable long-term schizophrenia patients.
基金supported by“Human Resources Program in Energy Technology”of the Korea Institute of Energy Technology Evaluation and Planning(KETEP),granted financial resources from the Ministry of Trade,Industry&Energy,Republic of Korea.(No.20204010600090).
文摘Segmenting brain tumors in Magnetic Resonance Imaging(MRI)volumes is challenging due to their diffuse and irregular shapes.Recently,2D and 3D deep neural networks have become famous for medical image segmentation because of the availability of labelled datasets.However,3D networks can be computationally expensive and require significant training resources.This research proposes a 3D deep learning model for brain tumor segmentation that uses lightweight feature extraction modules to improve performance without compromising contextual information or accuracy.The proposed model,called Hybrid Attention-Based Residual Unet(HA-RUnet),is based on the Unet architecture and utilizes residual blocks to extract low-and high-level features from MRI volumes.Attention and Squeeze-Excitation(SE)modules are also integrated at different levels to learn attention-aware features adaptively within local and global receptive fields.The proposed model was trained on the BraTS-2020 dataset and achieved a dice score of 0.867,0.813,and 0.787,as well as a sensitivity of 0.93,0.88,and 0.83 for Whole Tumor,Tumor Core,and Enhancing Tumor,on test dataset respectively.Experimental results show that the proposed HA-RUnet model outperforms the ResUnet and AResUnet base models while having a smaller number of parameters than other state-of-the-art models.Overall,the proposed HA-RUnet model can improve brain tumor segmentation accuracy and facilitate appropriate diagnosis and treatment planning for medical practitioners.
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.
基金supported by the Showa Shell Sekiyu Foundation for the promotion of environmental researchpartially by the Asahi Glass Foundation (grant number 68)
文摘Currently, most developing countries have not set up municipal solid waste management systems with a view of recovering energy from waste or reducing greenhouse gas emissions. In this article, we have studied the possible effects of introducing three energy recovery processes either as a single or combination approach, refuse derived fuel production,incineration and waste power generation, and methane gas recovery from landfill and power generation in Ulaanbaatar, Mongolia, as a case study. We concluded that incineration process is the most suitable as first introduction of energy recovery. To operate it efficiently,3Rs strategies need to be promoted. And then, RDF production which is made of waste papers and plastics in high level of sorting may be considered as the second step of energy recovery.However, safety control and marketability of RDF will be required at that moment.
文摘Background Atrial fibrillation （AF） causes a continuum of atrial anatomical remodeling. Methods Using a library of perfusion-fixed human hearts, specimens with AF were compared to controls. During this preliminary assessment study, direct measurements were taken of atrial volume, pulmonary vein （PV） circumference, and left atrial （LA） wall thicknesses. Results Hearts with AF typically had larger atrial volumes, as well as a much larger variation in volume compared to controls （range of 59.6-227.1 mL in AF hearts compared to 65.1-115.9 mL in controls）. For all hearts, right PVs were larger than left PVs （mean： 171.4 ± 84.6 mm^2 for right and 1182 ± 50.1 mm^2 for left, P 〈 0.005）. LA wall thicknesses ranged from 0.7 mm to 3.1 mm for both AF and control hearts. Conclusions Hearts with AF had a large range of sizes which is consistent with the progression of atrial remodeling during AF. The large range of thicknesses will influence the amount of energy needed to create transmural lesions during ablation procedures.
基金This work was done at the LTPMP Laboratory,USTHB,Algeria.
文摘Two-dimensional transient laminar natural convection in a square cavity containing a porous medium and inclined at an angle of 30°is investigated numerically.The vertical walls are differentially heated,and the horizontal walls are adiabatic.The effect of Rayleigh number on heat transfer and on the road to chaos is analyzed.The natural heat transfer and the Darcy Brinkman equations are solved by using a finite volume method and a Tri Diagonal Matrix Algorithm(TDMA).The results are obtained for a porosity equal to 0.45,a Darcy number and a Prandtl respectively equal to 10^(-3)and 0.71;they are analyzed in terms of streamlines,isotherms,phase portrait,attractors,and spectra amplitude as a function of the Rayleigh number.It is found that,as Rayleigh number increases,the natural convection changes from a steady state to a time-periodic state and finally to a chaotic condition.
基金Supported by(in part) National Center for Advancing Translational Sciences of the National Institutes of Health,No.UL1TR000454
文摘AIM To investigate changes in polyp detection throughout fellowship training, and estimate colonoscopy volume required to achieve the adenoma detection rate(ADRs) and polyp detection rate(PDRs) of attending gastroenterologists.METHODS We reviewed colonoscopies from July 1, 2009 to June 30, 2014. Fellows' procedural logs were used to retrieve colonoscopy procedural volumes, and these were treated as the time variable. Findings from screening colonoscopies were used to calculate colonoscopy outcomes for each fellow for the prior 50 colonoscopies at each time point. ADR and PDR were plotted against colonoscopy procedural volumes to produce individual longitudinal graphs. Repeated measures linear mixed effects models were used to study the change of ADR and PDR with increasing procedural volume.RESULTS During the study period, 12 fellows completed full three years of training and were included in the analysis. The average ADR and PDR were, respectively, 31.5% and 41.9% for all fellows, and 28.9% and 38.2% for attendings alone. There was a statistically significant increase in ADR with increasing procedural volume(1.8%/100 colonoscopies, P = 0.002). Similarly, PDR increased 2.8%/100 colonoscopies(P = 0.0001), while there was no significant change in advanced ADR(0.04%/100 colonoscopies, P = 0.92). The ADR increase was limited to the right side of the colon, while the PDR increased in both the right and left colon. The adenoma per colon and polyp per colon also increased throughout training. Fellows reached the attendings' ADR and PDR after 265 and 292 colonoscopies, respectively.CONCLUSION We found that the ADR and PDR increase with increasing colonoscopy volume throughout fellowship. Our findings support recent recommendations of ≥ 275 colonoscopies for colonoscopy credentialing.
文摘Overweight and obesity are highly prevalent in developed and developing countries among children and adolescents. During the last two decades, it became evident that excess weight is adversely related to respiratory health in childhood and adolescence mainly in terms of asthma occurrence. Additionally, there is a mounting body of evidence that overweight/obesity may also affect lung function in non-asthmatic subjects. The aim of this review was to present and discuss the studies that investigated this issue in non-asthmatic children and adolescents. Only a few studies have evaluated the impact of excess weight on static volumes and their results point towards an inverse relationship between overweight/obesity and functional residual capacity. More studies have been conducted on the impact of excess weight on dynamic lung volumes with inconsistent, however, results. Nevertheless, a relatively consistent finding was that the ratio of forced expiratory volume in 1 s/forced vital capacity was significantly lower among overweight/obese children compared to their counterparts with normal weight. The underlying mechanisms of these observations have not been adequately elucidated but it is believed to result from complex interaction of mechanical, developmental, and metabolic causes. There is a need for more welldesigned studies in order to clarify the impact of excess weight on lung function in non-asthmatic subjects, as well as to explore the contribution of factors such as duration and degree of obesity, and fat distribution. Despite the absence of conclusive data, there are stillconvincing evidence to be communicated to the children and their families as part of the arguments to encourage them to adopt a healthier lifestyle.
基金Supported by the National Council of Science and Technology(CONACyT)(SEP-2004-C01-47817)
文摘Densities(ρ) and dynamic viscosities(η) for three binary mixtures of n-decane with 1-pentanol,1-hexanol and1-heptanol are presented at temperatures from 293.15 to 363.15 K and atmospheric pressure over the entire composition range.The density and viscosity are measured using a vibrating tube densimeter and a cylindrical Couette type rotating viscometer,respectively.Excess molar volumes(V^E),viscosity deviations(△η) and excess Gibbs energy of activation of viscous flow(△G^(*E)) are calculated from the experimental measurements.Intermolecular and structural interactions are indicated by the sign and magnitude of these properties.Partial molar volumes and infinity dilution molar partial volumes are also calculated for each binary system.These results are correlated using Redlich-Kister type equations.
文摘The results stemming from the calculation of heat transfer in torch furnaces by the laws, relating to radiation from solid surfaces and gas volumes are analyzed. The article presents the laws for radiation from gas volumes and the procedure for calculating heat transfer in torch furnaces, fire boxes, and combustion chambers, elaborated on their basis. The example of heat transfer calculation in a torch furnace is given, and it is significantly non-uniform in nature. Non-uniformity of heat flux distribution on heating surfaces is given. According to the results of calculations, a new furnace is designed to decrease the non-uniformity of ingot heating, fuel rate, and increase the furnace capacity. The calculation results of the distribution of heat fluxes on the heating surfaces are given in changing torch geometric dimensions. These results are confirmed by experimental studies.
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.
