The deposition of spherical nanoparticles by convection and Brownian diffusion in a pipe with a cartilaginous ring structure is studied. Analytical results for a fully developed flow are found for small amplitude ring...The deposition of spherical nanoparticles by convection and Brownian diffusion in a pipe with a cartilaginous ring structure is studied. Analytical results for a fully developed flow are found for small amplitude rings using the interactive boundary layer theory. It is found that the local deposition rate is at maximum at a position approximately one twelfth of the spacing between the rings before the minimum cross section of the tube. For larger ring amplitudes the problem is solved numerically and separation then takes place in the depressions between the rings, and maximum deposition is found at the point of reattachment of the flow approximately at the same point as in the analytical theory. Cumulative deposition results are also provided with larger deposition rates with the inclusion of the cartilaginous rings. Deposition results for a developing flow are also provided. For the same volume flux as for fully developed flow the deposition is about 25% larger. In general conclusions about the position of maximum deposition rate from the analytic theory of fully developed flow also applies qualitatively to the case of developing flow.展开更多
In the present study, computational fluid dynamics （CFD） is used to investigate inspiratory and expiratory airflow characteristics in the human upper respiratory tract for the purpose of identifying the probable loc...In the present study, computational fluid dynamics （CFD） is used to investigate inspiratory and expiratory airflow characteristics in the human upper respiratory tract for the purpose of identifying the probable locations of particle deposition and the wall injury. Computed tomography （CT） scan data was used to reconstruct a three dimensional respiratory tract from trachea to first generation bronchi. To compare, a simplified model of respiratory tract based on Weibel was also used in the study. The steady state results are obtained for an airflow rate of 45 L/min, corresponding to the heavy breathing condition. The velocity distribution, wall shear stress, static pressure and particle deposition are compared for inspiratory flows in simplified and realistic models and expiratory flows in realistic model only. The results show that the location of cartilaginous rings is susceptible to wall injury and local particle deposition.展开更多
This paper presents a numerical study of the deposition of spherical charged nano-particles caused by convection, Brownian diffusion and electrostatics in a pipe with a cartilaginous ring structure. The model describe...This paper presents a numerical study of the deposition of spherical charged nano-particles caused by convection, Brownian diffusion and electrostatics in a pipe with a cartilaginous ring structure. The model describes the deposition of charged particles in the different generations of the tracheobronchial tree of the human lung. The upper airways are characterized by a certain wall structure called cartilaginous rings which modify the particle deposition when compared to an airway with a smooth wall. The problem is defined by solving Naver-Stokes equations in combination with a convective-diffusion equation and Gauss law for electrostatics. Three non- dimensional parameters describe the problem, the Peclet number Pe = 2ūa/D , the Reynolds number Re = ūa/v and an electrostatic parameter α=α2c0q2/(4ε0κT) . Here U is the mean velocity, a the pipe radius and D the diffusion coefficient due to Brownian motion given by D=κTCu/3πμd , where Cu is the Cunningham-factor Cu=1+λ/d(2.34+1.05exp(-0.39d/λ)) Here d is the particle diameter and λ the mean free path of the air molecules. Results are provided for generations G4-G16 of the human airways. The electrostatic parameter is varied to model different concentrations and charge numbers.展开更多
Meningiomas are the most common extra-axial central nervous system tumours and often discovered in the middle to late adult life and especially in women. About 85%-90% of meningiomas are benign, 5%-10% are intermediat...Meningiomas are the most common extra-axial central nervous system tumours and often discovered in the middle to late adult life and especially in women. About 85%-90% of meningiomas are benign, 5%-10% are intermediate-grade, and 3%-5% are malignant. Metaplastic meningioma is a rare subtype of WHO Grade I meningioma histologically characterized by the presence of mesenchymal components. The presence of pure and extensive cartilaginous differentiation in meningiomas is extremely rare and remains a diagnostic dilemma. We report, perhaps the first case of this entity in a 52-year-old woman and discuss the pathogenesis, the imaging features and the histopathologicals data.展开更多
Objective To summarize the experiences of treating secondary,cartilaginous oblique deviated noses and explore an effective technique to improve the clinical efficacy. Methods Through open approach,anterior and inferio...Objective To summarize the experiences of treating secondary,cartilaginous oblique deviated noses and explore an effective technique to improve the clinical efficacy. Methods Through open approach,anterior and inferior margin of quadrangular cartilage was展开更多
The Mediterranean Sea is home to an interesting biodiversity. The current cumulative and descriptive study aims to enumerate some relatively large marine mammals, reptiles, and fishes that have been spotted, caught, b...The Mediterranean Sea is home to an interesting biodiversity. The current cumulative and descriptive study aims to enumerate some relatively large marine mammals, reptiles, and fishes that have been spotted, caught, by-caught, or stranded on the coast of the Gaza Strip, Palestine, which extends about 42 km along the Mediterranean Sea. This 20-year study from 2003 to 2022 relied much on frequent field visits, meetings, and discussions with stakeholders, following local media sites and social media pages, and photography. The study recorded at least 26 giants or relatively large marine organisms on the Mediterranean coast of the Gaza Strip, Palestine. Certainly, the coming years may bring other marine organisms of relatively large sizes. Marine mammals included three species of cetaceans with the Fin Whale (Balaenoptera physalus) being the largest mammal and even the largest animal ever recorded in this study. Marine reptiles included three species of sea turtles, the largest of which is the Leatherback Sea Turtle (Dermochelys coriacea), which is in fact the world’s largest sea turtle. The bony fishes were represented by ten species, the largest of which was the Ocean Sunfish (Mola mola), which is the largest bony fish in the world. The cartilaginous fishes included ten species with the largest specimens encountered were the Shortfin Shark (Isurus oxyrinchus), Bluntnose Sixgill Shark (Hexanchus griseus), Scalloped Hammerhead Shark (Sphyrna lewini), and Giant Devil Ray (Mobula mobular). Seabirds were not included in the study. The Alexandria Pompano (Alectis alexandrinus) and the Silver-Cheeked Toadfish (Lagocephalus sceleratus), which are bony fishes, appear to be the relatively smallest marine organisms recorded here. In conclusion, the role of the various parties must be coordinated to ensure the sustainability of human activities and their compatibility with the task of conserving local marine biota, including the gigantic or relatively large ones.展开更多
A 60-year-old Hispanic male presented to his primary care physician office with an asymptomatic, but palpable right anterior chest wall mass. Initial work up of the finding included a CT scan of the chest which reveal...A 60-year-old Hispanic male presented to his primary care physician office with an asymptomatic, but palpable right anterior chest wall mass. Initial work up of the finding included a CT scan of the chest which revealed a non-calcified, solid right anterior chest wall mass with invasion of the anterior fifth rib and intercostal space. The patient was presented at multidisciplinary conference with the patient’s primary physician, a medical oncologist, radiologist, pathologist and oncologic surgeon in attendance. The decision was to perform surgical resection of the mass to treat this primary mesenchymal malignancy. The anterior aspect of the fifth rib and intercostal muscles were resected with negative margins. Pathology confirmed the mass to be a low-grade chondrosarcoma. Due to the low-grade nature, low metastatic potential and negative margins of the tumor, the decision was made not to pursue adjuvant chemotherapy or radiation therapy. The patient made full recovery.展开更多
BACKGROUND Chondromyxoid fibroma(CMF)is an unusual benign tumour of cartilaginous tissues that may be confused with other malignant tumours.It is rarely seen in the cervical spine.CASE SUMMARY A 24-year-old young woma...BACKGROUND Chondromyxoid fibroma(CMF)is an unusual benign tumour of cartilaginous tissues that may be confused with other malignant tumours.It is rarely seen in the cervical spine.CASE SUMMARY A 24-year-old young woman was admitted to the hospital because of neck and shoulder pain.Computed tomography,magnetic resonance imaging,X-ray and other imaging examinations of the cervical spine and laboratory-related indicators combined with intraoperative pathology revealed that the patient had cervical CMF.We performed total resection of the vertebral body and intervertebral disc,and internal fixation was performed to simultaneously maintain the stability of the entire spine.The clinical results from extensive resection were satisfactory.At the 2-year follow-up,the patient's symptoms had not recurred.CONCLUSION CMF is a benign primary bone tumour that is rarely located in the vertebral bone.Accurate initial diagnosis of these tumours is important for appropriate treatment.En bloc surgical resection of the tumour is the cornerstone of treatment.展开更多
Relapsing polychondritis (RP) is a rare episodic and progressive inflammatory disease of presumed autoimmune etiology. The estimated incidence is 3.5 cases per million. Of these only 10% affect pediatric populations.
文摘The deposition of spherical nanoparticles by convection and Brownian diffusion in a pipe with a cartilaginous ring structure is studied. Analytical results for a fully developed flow are found for small amplitude rings using the interactive boundary layer theory. It is found that the local deposition rate is at maximum at a position approximately one twelfth of the spacing between the rings before the minimum cross section of the tube. For larger ring amplitudes the problem is solved numerically and separation then takes place in the depressions between the rings, and maximum deposition is found at the point of reattachment of the flow approximately at the same point as in the analytical theory. Cumulative deposition results are also provided with larger deposition rates with the inclusion of the cartilaginous rings. Deposition results for a developing flow are also provided. For the same volume flux as for fully developed flow the deposition is about 25% larger. In general conclusions about the position of maximum deposition rate from the analytic theory of fully developed flow also applies qualitatively to the case of developing flow.
基金funded by Department of Science & Technology Government of India through the DST-FIST grant
文摘In the present study, computational fluid dynamics （CFD） is used to investigate inspiratory and expiratory airflow characteristics in the human upper respiratory tract for the purpose of identifying the probable locations of particle deposition and the wall injury. Computed tomography （CT） scan data was used to reconstruct a three dimensional respiratory tract from trachea to first generation bronchi. To compare, a simplified model of respiratory tract based on Weibel was also used in the study. The steady state results are obtained for an airflow rate of 45 L/min, corresponding to the heavy breathing condition. The velocity distribution, wall shear stress, static pressure and particle deposition are compared for inspiratory flows in simplified and realistic models and expiratory flows in realistic model only. The results show that the location of cartilaginous rings is susceptible to wall injury and local particle deposition.
文摘This paper presents a numerical study of the deposition of spherical charged nano-particles caused by convection, Brownian diffusion and electrostatics in a pipe with a cartilaginous ring structure. The model describes the deposition of charged particles in the different generations of the tracheobronchial tree of the human lung. The upper airways are characterized by a certain wall structure called cartilaginous rings which modify the particle deposition when compared to an airway with a smooth wall. The problem is defined by solving Naver-Stokes equations in combination with a convective-diffusion equation and Gauss law for electrostatics. Three non- dimensional parameters describe the problem, the Peclet number Pe = 2ūa/D , the Reynolds number Re = ūa/v and an electrostatic parameter α=α2c0q2/(4ε0κT) . Here U is the mean velocity, a the pipe radius and D the diffusion coefficient due to Brownian motion given by D=κTCu/3πμd , where Cu is the Cunningham-factor Cu=1+λ/d(2.34+1.05exp(-0.39d/λ)) Here d is the particle diameter and λ the mean free path of the air molecules. Results are provided for generations G4-G16 of the human airways. The electrostatic parameter is varied to model different concentrations and charge numbers.
文摘Meningiomas are the most common extra-axial central nervous system tumours and often discovered in the middle to late adult life and especially in women. About 85%-90% of meningiomas are benign, 5%-10% are intermediate-grade, and 3%-5% are malignant. Metaplastic meningioma is a rare subtype of WHO Grade I meningioma histologically characterized by the presence of mesenchymal components. The presence of pure and extensive cartilaginous differentiation in meningiomas is extremely rare and remains a diagnostic dilemma. We report, perhaps the first case of this entity in a 52-year-old woman and discuss the pathogenesis, the imaging features and the histopathologicals data.
文摘Objective To summarize the experiences of treating secondary,cartilaginous oblique deviated noses and explore an effective technique to improve the clinical efficacy. Methods Through open approach,anterior and inferior margin of quadrangular cartilage was
文摘The Mediterranean Sea is home to an interesting biodiversity. The current cumulative and descriptive study aims to enumerate some relatively large marine mammals, reptiles, and fishes that have been spotted, caught, by-caught, or stranded on the coast of the Gaza Strip, Palestine, which extends about 42 km along the Mediterranean Sea. This 20-year study from 2003 to 2022 relied much on frequent field visits, meetings, and discussions with stakeholders, following local media sites and social media pages, and photography. The study recorded at least 26 giants or relatively large marine organisms on the Mediterranean coast of the Gaza Strip, Palestine. Certainly, the coming years may bring other marine organisms of relatively large sizes. Marine mammals included three species of cetaceans with the Fin Whale (Balaenoptera physalus) being the largest mammal and even the largest animal ever recorded in this study. Marine reptiles included three species of sea turtles, the largest of which is the Leatherback Sea Turtle (Dermochelys coriacea), which is in fact the world’s largest sea turtle. The bony fishes were represented by ten species, the largest of which was the Ocean Sunfish (Mola mola), which is the largest bony fish in the world. The cartilaginous fishes included ten species with the largest specimens encountered were the Shortfin Shark (Isurus oxyrinchus), Bluntnose Sixgill Shark (Hexanchus griseus), Scalloped Hammerhead Shark (Sphyrna lewini), and Giant Devil Ray (Mobula mobular). Seabirds were not included in the study. The Alexandria Pompano (Alectis alexandrinus) and the Silver-Cheeked Toadfish (Lagocephalus sceleratus), which are bony fishes, appear to be the relatively smallest marine organisms recorded here. In conclusion, the role of the various parties must be coordinated to ensure the sustainability of human activities and their compatibility with the task of conserving local marine biota, including the gigantic or relatively large ones.
文摘A 60-year-old Hispanic male presented to his primary care physician office with an asymptomatic, but palpable right anterior chest wall mass. Initial work up of the finding included a CT scan of the chest which revealed a non-calcified, solid right anterior chest wall mass with invasion of the anterior fifth rib and intercostal space. The patient was presented at multidisciplinary conference with the patient’s primary physician, a medical oncologist, radiologist, pathologist and oncologic surgeon in attendance. The decision was to perform surgical resection of the mass to treat this primary mesenchymal malignancy. The anterior aspect of the fifth rib and intercostal muscles were resected with negative margins. Pathology confirmed the mass to be a low-grade chondrosarcoma. Due to the low-grade nature, low metastatic potential and negative margins of the tumor, the decision was made not to pursue adjuvant chemotherapy or radiation therapy. The patient made full recovery.
文摘BACKGROUND Chondromyxoid fibroma(CMF)is an unusual benign tumour of cartilaginous tissues that may be confused with other malignant tumours.It is rarely seen in the cervical spine.CASE SUMMARY A 24-year-old young woman was admitted to the hospital because of neck and shoulder pain.Computed tomography,magnetic resonance imaging,X-ray and other imaging examinations of the cervical spine and laboratory-related indicators combined with intraoperative pathology revealed that the patient had cervical CMF.We performed total resection of the vertebral body and intervertebral disc,and internal fixation was performed to simultaneously maintain the stability of the entire spine.The clinical results from extensive resection were satisfactory.At the 2-year follow-up,the patient's symptoms had not recurred.CONCLUSION CMF is a benign primary bone tumour that is rarely located in the vertebral bone.Accurate initial diagnosis of these tumours is important for appropriate treatment.En bloc surgical resection of the tumour is the cornerstone of treatment.
文摘Relapsing polychondritis (RP) is a rare episodic and progressive inflammatory disease of presumed autoimmune etiology. The estimated incidence is 3.5 cases per million. Of these only 10% affect pediatric populations.
