ahmed noor - Academia.edu (original) (raw)
Papers by ahmed noor
The document contains the proceedings of the training workshop on Emerging and Future Computing P... more The document contains the proceedings of the training workshop on Emerging and Future Computing Paradigms and their impact on the Research, Training and Design Environments of the Aerospace Workforce. The workshop was held at NASA Langley Research Center, Hampton, Virginia, March 18 and 19, 2003. The workshop was jointly sponsored by Old Dominion University and NASA. Workshop attendees came from NASA, other government agencies, industry and universities. The objectives of the workshop were to a) provide broad overviews of the diverse activities related to new computing paradigms, including grid computing, pervasive computing, high-productivity computing, and the IBM-led autonomic computing; and b) identify future directions for research that have high potential for future aerospace workforce environments. The format of the workshop included twenty-one, half-hour overview-type presentations and three exhibits by vendors.
Mechanical Engineering, 2010
This article provides an overview of various technologies meant for developing intelligent digita... more This article provides an overview of various technologies meant for developing intelligent digital engineering ecosystems. The article also highlights the need to develop new methods for combining visual and haptic impressions to provide a high degree of immersion, and enable touching and moving virtual objects. Some current activities are devoted to studying and improving the relation between humans and computing devices. One of these activities is the Human–Computer Confluence, an interdisciplinary initiative funded by the European Commission, as part of its Future and Emerging Technologies program. Intelligent digital engineering ecosystems will closely link research and academic institutions with industry and policymakers, and will facilitate the networking of innovation knowledge. They will enable the widespread adoption of augmented reality; the seamless integration of virtual and physical worlds; establishing a new baseline for human functionality; and experimentation with no...
The workshop was jointly sponsored by Old Dominion University and NASA. Workshop attendees came f... more The workshop was jointly sponsored by Old Dominion University and NASA. Workshop attendees came from NASA, other government agencies, industry, and universities. The objectives of the workshop were to review the diverse activities in hierarchical approach to material modeling from continuum to atomistics; applications of multiscale modeling to advanced and improved material synthesis; defects, dislocations, and material deformation; fracture and friction; thin-film growth; characterization at nano and micro scales; and, verification and validation of numerical simulations, and to identify their potential for future aerospace systems.
Engineering Computations, 2001
An object‐oriented event‐driven immersive virtual environment is described for the creation of vi... more An object‐oriented event‐driven immersive virtual environment is described for the creation of virtual labs (VLs) for simulating physical experiments. Discussion focuses on a number of aspects of the VLs, including interface devices, software objects, and various applications. The VLs interface with output devices, including immersive stereoscopic screen(s) and stereo speakers; and a variety of input devices, including body tracking (head and hands), haptic gloves, wand, joystick, mouse, microphone, and keyboard. The VL incorporates the following types of primitive software objects: interface objects, support objects, geometric entities, and finite elements. Each object encapsulates a set of properties, methods, and events that define its behavior, appearance, and functions. A “container” object allows grouping of several objects. Applications of the VLs include viewing the results of the physical experiment, viewing a computer simulation of the physical experiment, simulation of th...
Computer Methods in Applied Mechanics and Engineering, 2000
Multibody dynamic simulations are performed for a large deployable space structure using ®nite el... more Multibody dynamic simulations are performed for a large deployable space structure using ®nite element models and an explicit temporal integration procedure. The structure considered is NASA's lightweight , 8 m-aperture next generation space telescope (NGST). The NGST structure consists of beam components (modeled using beam``super-elements'', each composed of two truss elements and a torsional spring), thin-surface shell-type components (modeled using super-elements, each composed of one brick, twelve truss elements, and six surface elements), revolute and prismatic joints, and reaction wheels. Detailed numerical simulations are conducted for the vibrational response, attitude control, and deployment. A fuzzy-set technique is used to assess the eect of changing the dwell time of the various deployment actuators on the total strain energy of the structure. Published by Elsevier Science S.A. All rights reserved.
Computer, 1998
Beyond Incremental Change he International Space Station-the largest space venture ever undertake... more Beyond Incremental Change he International Space Station-the largest space venture ever undertaken, involving a range of complex activities by teams from 16 countries-marks an era of unprecedented global partnerships in space science and exploration. 1 It is the result of an explosive growth in computing power and connectivity, which is reshaping relationships among researchers and organizations. This reshaping in turn has prompted a cultural shift in engineering and scientific creativity. But even the ISS seems insignificant when we look at some of NASA's goals over the next 25 years: In earth science, we want to accurately predict climate and resources over decades, not just days. In space science, we want to detect Earth-sized planets 600 trillion miles away with a telescope powerful enough to determine signs of life. In human exploration, we want to use the ISS as a platform for an astronaut to visit Mars or maybe work on a research station on a near-Earth asteroid. This is the big vision, and to many it may sound more like science fiction. Those who doubt we can accomplish this vision are the people who are still thinking in small steps. A big vision demands equally big steps. It means we stop clinging to hard computing and the comfort zone of numerical calculation. It means we turn to processes that more closely resemble human intelligence that turn out products more closely resembling the human body. We need space systems that can learn and adapt as they go, essentially performing their own mission tasking. We need modularity on a scale from chip to system. We need miniaturization that can let us put the entire avionics on one chip-a spacecraft that will fit in the palm of your hand. We need materials that will withstand temperatures 10 times higher than Apollo encountered during its reentry into Earth's atmosphere. On the surface, these goals, like the big vision, seem unreachable-and right now they are-but we have taken a large first step to get there. In 1997, NASA and the University of Virginia's Center for Advanced Computational Technology began planning and developing the Intelligent Synthesis Environment. The ISE Cybersquare The complex high-tech systems envisioned for the next decades demand revolutionary, not evolutionary, change. NASA's Intelligent Synthesis Environment emphasizes a shift in the way people think about and use computing, promising to significantly alter engineering and scientific creative processes.
Applied Mechanics Reviews, 2003
The status and some recent developments in computational modeling of flexible multibody systems a... more The status and some recent developments in computational modeling of flexible multibody systems are summarized. Discussion focuses on a number of aspects of flexible multibody dynamics including: modeling of the flexible components, constraint modeling, solution techniques, control strategies, coupled problems, design, and experimental studies. The characteristics of the three types of reference frames used in modeling flexible multibody systems, namely, floating frame, corotational frame, and inertial frame, are compared. Future directions of research are identified. These include new applications such as micro- and nano-mechanical systems; techniques and strategies for increasing the fidelity and computational efficiency of the models; and tools that can improve the design process of flexible multibody systems. This review article cites 877 references.
Advances in Engineering Software, 2004
An intelligent virtual environment is described for training users in the operation of complex en... more An intelligent virtual environment is described for training users in the operation of complex engineering systems. The environment combines an intelligent agent facility, for tutoring, guiding and/or supervising the training; an object-oriented virtual environment engine, for displaying the engineering system; and a simulator, for simulating the system controls. The intelligent agent facility includes: (a) a hierarchical process knowledge base, (b) a rule-based expert system for natural language understanding, and (c) a human-like virtual characters engine. Three types of objects are used for representing the process knowledge, namely, processes, steps, and constraints. An application of the environment to the interactive training for operating a NASA wind tunnel is described. Two agents in the environment can perform several functions, including conducting an interactive virtual tour of the facility; guiding and supervising the training, as well as certifying the trainee.
Advances in Engineering Software, 2004
An interrogative visualization environment is described for the interactive display and querying ... more An interrogative visualization environment is described for the interactive display and querying of large datasets. The environment combines a web-based intelligent agent facility with a visualization engine. The intelligent agent facility (IAF) incorporates a rule-based expert system for natural-language understanding, voice and text input facilities, a hierarchical clickable command list, an interface for multimodal devices such as menu-based wireless handheld devices and gesture recognition devices, and human-like avatars acting as virtual assistants. The IAF interacts with, and controls, the visualization engine through a TCP/IP network socket interface. The environment enables multiple users using a variety of interaction modes and devices to effectively browse through large amounts of data, focus on and query interesting features, and more easily comprehend and make use of the data. Application of the environment to the visualization of engineering simulations is described.
Pacing and Clinical Electrophysiology, 2019
Patients eligible for primary prevention implantable cardioverter‐defibrillator (ICD) therapy are... more Patients eligible for primary prevention implantable cardioverter‐defibrillator (ICD) therapy are faced with a complex decision that needs a clear understanding of the risks and benefits of such an intervention. In this study, our goal was to explore the documentation of primary prevention ICD discussions in the electronic medical records (EMRs) of eligible patients.
Chest, 2019
Pulmonary hypertension is grouped into 5 broad categories according to the WHO classification. In... more Pulmonary hypertension is grouped into 5 broad categories according to the WHO classification. In rheumatologic disease, the source of elevated pulmonary arterial pressure has many possibilities. Due to the complexity of these patients there remains diagnostic and therapeutic challenges.
American Journal of Gastroenterology, 2019
diarrhea with 5-6 bowel movements/day from last 2-3 months, 30 pound unintentional weight loss in... more diarrhea with 5-6 bowel movements/day from last 2-3 months, 30 pound unintentional weight loss in last 2 months, occasional night sweats. He denied any episodes of flushing. On presentation, vitals were stable. Other labs included CBC-wnl, BUN-25 mg/dl with creatinine of 3 (baseline 2), albumin-2.4, AST-19u/l, ALT-26u/l, ALP-210 u/l, total bilirubin 0.9 mg/dl. Clostridium difficle screen and GI panel were negative. Last colonoscopy, done one month prior to presentation was normal. He was started on Imodium without any relief. Gastroenterology service was consulted for further management. His chromogranin A was found to be 782 (, 93), 5HIAAA was 50 (, 8). He underwent ultrasound of the abdomen for this acute kidney injury which revealed 5.9 3 5.9 3 5.9 cm hyperechoic mass with central decreased echogenicity located within the liver. AFP was 1.1 ng/ml (, 8 ng/ ml), CEA 7.4 ng/ml (3 ng/ml). Meanwhile, he was started on sandostatin which helped a lot with his diarrhea. Further imaging of this abdomen was deferred due to kidney injury. He had previous PET scan done 3-4 years ago revealed increased uptake in liver but were inconsistent of any metastatis. His last abdominal CT scan done 2-3 years ago was negative of any metastasis. Two weeks after his discharge, he was readmitted to intensive care unit (ICU) with septic shock and unfortunately he passed away. DISCUSSION: Carcinoid tumors are relatively slow growing compared to adenocarcinomas of the same site and have a tendency for recurrence. The NANETS Consensus Guideline for the Diagnosis and Management of Neuroendocrine Tumors recommends an office follow up every 6 to12 months for 7 years. Either radiographic (CT/MRI) or endoscopic methods could be used for surveillance. The secretory tumors can be followed up by monitoring the levels of urinary 5-HIAA and serum chromogranin A.
Saudi Pharmaceutical Journal, 2017
Objective: To evaluate the association between the level of vitamin D and glycemic control among ... more Objective: To evaluate the association between the level of vitamin D and glycemic control among patients with diabetes. Research design and method: We analyzed data collected from NHANES 2003-2006. We included only non-pregnant adult diabetic persons 18 years or older. Participants who had vitamin D level less than 20 ng/ml were considered as having vitamin D deficiency. Participants were considered to have a glucose control if the HbA 1c level was less than 7% [53 mmol/L]. We used student's t test to compare the difference in HbA 1c means between people with Diabetes with and without a vitamin D deficiency. We used a multivariate logistic regression model to predict the relationship between glucose control and vitamin D deficiency. We used race/ethnicity, BMI, age, gender, type of diabetic medication used, having health insurance or not, and comorbid conditions (hypertension, anemia, cholesterol, liver disease, and kidney disease) as control variables. Results: The study population included a total of 929 non-institutionalized, non-pregnant, diabetic adult persons. About 57% of patients with diabetes had a vitamin D deficiency. Blacks (non-Hispanic patients) with diabetes had the highest rate of vitamin D deficiency (79%). The unadjusted means of HbA 1c were significantly different between diabetic patients with no vitamin D deficiency and those with a vitamin D deficiency (7.06% [54 mmol/L], 7.56 % [59 mmol/L], respectively, P < 0.0001). Multivariate adjustment showed a small but not significant, increase in odds (11%) of having uncontrolled diabetes in patients with a vitamin D deficiency after adjustment for other factors. Conclusion: Vitamin D deficiency is very common in patients with diabetes. We found no significant association between vitamin D level and glycemic control in patients with diabetes after adjustment for control variables.
Nebraska Law Review, 1970
For the past twelve years Robert Van Pelt has served as Federal District Judge for the District o... more For the past twelve years Robert Van Pelt has served as Federal District Judge for the District of Nebraska. An assessment of his distinguished career at this time would be somewhat premature, as no doubt his schedule will remain quite demanding. However, the retirement of this capable jurist calls for a brief review of his outstanding career.
... Chang..... 3 TECHNOLOGY OVERVIEW MATERIALS AND STRUCTURES..... 13 Structures and Materials Im... more ... Chang..... 3 TECHNOLOGY OVERVIEW MATERIALS AND STRUCTURES..... 13 Structures and Materials Impasse?, William A. Mrazek..... 15 Structures and Materials (State of the Art1960), George Gerard..... 23 ...
Journal of the College of Physicians and Surgeons--Pakistan : JCPSP, 2005
To assess the risk factors associated with development of ventilator associated pneumonia (VAP). ... more To assess the risk factors associated with development of ventilator associated pneumonia (VAP). A case control study. Intensive Care Unit (ICU) at the Aga Khan University Hospital, Karachi, between January 1999 and June 2000. All patients with assisted mechanical ventilation were assessed for the development of VAP. Risk factors associated with development of VAP were determined. Adult patients who developed pneumonia, 48 hours after ventilation, were called cases while those who did not develop pneumonia were called controls. Seventy (28%) out of 250 mechanically ventilated patients developed VAP (rate of VAP was 26 cases per 1000 ventilator days). Shock during first 48 hours of ventilation (odds ratio (OR), 5.95; 95% confidence interval (CI), 2.83-12.52), transport out of ICU during mechanical ventilation (OR, 6.0; 95% CI, 2.92-12.37), re-intubation (OR, 4.23; 95% CI, 2.53-9.85), prior episode of aspiration of gastric content (OR, 3.07; 95% CI, 1.35-7.01), and use of antibiotics ...
Advances in Engineering Software, 2014
38th Structures, Structural Dynamics, and Materials Conference, 1997
The results of a detailed study of the nonlinear response of curved sandwich panels with composit... more The results of a detailed study of the nonlinear response of curved sandwich panels with composite face sheets and subjected to a temperature gradient through the thickness combined with mechanical loadings are presented. The analysis is based on a first-order sheardeformation Sanders-Budiansky type theory with the effects of large displacements, moderate rotations, transverse shear deformation and laminated anisotropic material behavior included. A mixed formulation is used with the fundamental unknowns consisting of the generalized displacements and the stress resultants of the panel. The nonlinear displacements, strain energy, principal strains, transverse shear stresses, transverse shear strain energy density, and their hierarchical sensitivity coefficients are evaluated. The hierarchical sensitivity coefficients measure the sensitivity of the nonlinear response to variations hi the panel parameters, the effective properties of the face sheet layers and the core, and the micromechanical parameters. Numerical results are presented for cylindrical panels subjected to combined pressure loading, edge shortening or extension, edge shear and a temperature gradient through the thickness. The results show the effects of variations in the loading and the panel aspect ratio, on the nonlinear response and its sensitivity to changes in the various panel, effective layer and micromechanical parameters. Nomenclature
Applied Physics A, 2013
Atomic layer deposited thin HfO 2 film has been demonstrated to act as a pore-sealing layer and a... more Atomic layer deposited thin HfO 2 film has been demonstrated to act as a pore-sealing layer and a Cu diffusion barrier layer used in porous low-k dielectrics. This study investigates the effect of annealing temperature on the electrical characteristics and reliability of the dielectric stacks with HfO 2 and porous low-k films. The experimental results reveal that annealing improved electrical performance and reliability, but increased the dielectric constant. However, the resulting dielectric constant of the annealed HfO 2 /porous low-k dielectric stacks following oxygen plasma treatment was still lower than that of the dielectric stacks without annealing, indicating that annealing improved the properties of HfO 2 /porous low-k dielectric stacks. Annealing at 400°C improved electrical characteristics, reliability, and Cu barrier performance more than did annealing at 600°C because at 600°C annealing, the grain boundaries of the crystallized HfO 2 film provide a conduction path and cause the breakage of the porous low-k film. However, the HfO 2 /porous low-k dielectric stacks that were annealed at 600°C exhibited greater resistance against damage by oxygen plasma.
The document contains the proceedings of the training workshop on Emerging and Future Computing P... more The document contains the proceedings of the training workshop on Emerging and Future Computing Paradigms and their impact on the Research, Training and Design Environments of the Aerospace Workforce. The workshop was held at NASA Langley Research Center, Hampton, Virginia, March 18 and 19, 2003. The workshop was jointly sponsored by Old Dominion University and NASA. Workshop attendees came from NASA, other government agencies, industry and universities. The objectives of the workshop were to a) provide broad overviews of the diverse activities related to new computing paradigms, including grid computing, pervasive computing, high-productivity computing, and the IBM-led autonomic computing; and b) identify future directions for research that have high potential for future aerospace workforce environments. The format of the workshop included twenty-one, half-hour overview-type presentations and three exhibits by vendors.
Mechanical Engineering, 2010
This article provides an overview of various technologies meant for developing intelligent digita... more This article provides an overview of various technologies meant for developing intelligent digital engineering ecosystems. The article also highlights the need to develop new methods for combining visual and haptic impressions to provide a high degree of immersion, and enable touching and moving virtual objects. Some current activities are devoted to studying and improving the relation between humans and computing devices. One of these activities is the Human–Computer Confluence, an interdisciplinary initiative funded by the European Commission, as part of its Future and Emerging Technologies program. Intelligent digital engineering ecosystems will closely link research and academic institutions with industry and policymakers, and will facilitate the networking of innovation knowledge. They will enable the widespread adoption of augmented reality; the seamless integration of virtual and physical worlds; establishing a new baseline for human functionality; and experimentation with no...
The workshop was jointly sponsored by Old Dominion University and NASA. Workshop attendees came f... more The workshop was jointly sponsored by Old Dominion University and NASA. Workshop attendees came from NASA, other government agencies, industry, and universities. The objectives of the workshop were to review the diverse activities in hierarchical approach to material modeling from continuum to atomistics; applications of multiscale modeling to advanced and improved material synthesis; defects, dislocations, and material deformation; fracture and friction; thin-film growth; characterization at nano and micro scales; and, verification and validation of numerical simulations, and to identify their potential for future aerospace systems.
Engineering Computations, 2001
An object‐oriented event‐driven immersive virtual environment is described for the creation of vi... more An object‐oriented event‐driven immersive virtual environment is described for the creation of virtual labs (VLs) for simulating physical experiments. Discussion focuses on a number of aspects of the VLs, including interface devices, software objects, and various applications. The VLs interface with output devices, including immersive stereoscopic screen(s) and stereo speakers; and a variety of input devices, including body tracking (head and hands), haptic gloves, wand, joystick, mouse, microphone, and keyboard. The VL incorporates the following types of primitive software objects: interface objects, support objects, geometric entities, and finite elements. Each object encapsulates a set of properties, methods, and events that define its behavior, appearance, and functions. A “container” object allows grouping of several objects. Applications of the VLs include viewing the results of the physical experiment, viewing a computer simulation of the physical experiment, simulation of th...
Computer Methods in Applied Mechanics and Engineering, 2000
Multibody dynamic simulations are performed for a large deployable space structure using ®nite el... more Multibody dynamic simulations are performed for a large deployable space structure using ®nite element models and an explicit temporal integration procedure. The structure considered is NASA's lightweight , 8 m-aperture next generation space telescope (NGST). The NGST structure consists of beam components (modeled using beam``super-elements'', each composed of two truss elements and a torsional spring), thin-surface shell-type components (modeled using super-elements, each composed of one brick, twelve truss elements, and six surface elements), revolute and prismatic joints, and reaction wheels. Detailed numerical simulations are conducted for the vibrational response, attitude control, and deployment. A fuzzy-set technique is used to assess the eect of changing the dwell time of the various deployment actuators on the total strain energy of the structure. Published by Elsevier Science S.A. All rights reserved.
Computer, 1998
Beyond Incremental Change he International Space Station-the largest space venture ever undertake... more Beyond Incremental Change he International Space Station-the largest space venture ever undertaken, involving a range of complex activities by teams from 16 countries-marks an era of unprecedented global partnerships in space science and exploration. 1 It is the result of an explosive growth in computing power and connectivity, which is reshaping relationships among researchers and organizations. This reshaping in turn has prompted a cultural shift in engineering and scientific creativity. But even the ISS seems insignificant when we look at some of NASA's goals over the next 25 years: In earth science, we want to accurately predict climate and resources over decades, not just days. In space science, we want to detect Earth-sized planets 600 trillion miles away with a telescope powerful enough to determine signs of life. In human exploration, we want to use the ISS as a platform for an astronaut to visit Mars or maybe work on a research station on a near-Earth asteroid. This is the big vision, and to many it may sound more like science fiction. Those who doubt we can accomplish this vision are the people who are still thinking in small steps. A big vision demands equally big steps. It means we stop clinging to hard computing and the comfort zone of numerical calculation. It means we turn to processes that more closely resemble human intelligence that turn out products more closely resembling the human body. We need space systems that can learn and adapt as they go, essentially performing their own mission tasking. We need modularity on a scale from chip to system. We need miniaturization that can let us put the entire avionics on one chip-a spacecraft that will fit in the palm of your hand. We need materials that will withstand temperatures 10 times higher than Apollo encountered during its reentry into Earth's atmosphere. On the surface, these goals, like the big vision, seem unreachable-and right now they are-but we have taken a large first step to get there. In 1997, NASA and the University of Virginia's Center for Advanced Computational Technology began planning and developing the Intelligent Synthesis Environment. The ISE Cybersquare The complex high-tech systems envisioned for the next decades demand revolutionary, not evolutionary, change. NASA's Intelligent Synthesis Environment emphasizes a shift in the way people think about and use computing, promising to significantly alter engineering and scientific creative processes.
Applied Mechanics Reviews, 2003
The status and some recent developments in computational modeling of flexible multibody systems a... more The status and some recent developments in computational modeling of flexible multibody systems are summarized. Discussion focuses on a number of aspects of flexible multibody dynamics including: modeling of the flexible components, constraint modeling, solution techniques, control strategies, coupled problems, design, and experimental studies. The characteristics of the three types of reference frames used in modeling flexible multibody systems, namely, floating frame, corotational frame, and inertial frame, are compared. Future directions of research are identified. These include new applications such as micro- and nano-mechanical systems; techniques and strategies for increasing the fidelity and computational efficiency of the models; and tools that can improve the design process of flexible multibody systems. This review article cites 877 references.
Advances in Engineering Software, 2004
An intelligent virtual environment is described for training users in the operation of complex en... more An intelligent virtual environment is described for training users in the operation of complex engineering systems. The environment combines an intelligent agent facility, for tutoring, guiding and/or supervising the training; an object-oriented virtual environment engine, for displaying the engineering system; and a simulator, for simulating the system controls. The intelligent agent facility includes: (a) a hierarchical process knowledge base, (b) a rule-based expert system for natural language understanding, and (c) a human-like virtual characters engine. Three types of objects are used for representing the process knowledge, namely, processes, steps, and constraints. An application of the environment to the interactive training for operating a NASA wind tunnel is described. Two agents in the environment can perform several functions, including conducting an interactive virtual tour of the facility; guiding and supervising the training, as well as certifying the trainee.
Advances in Engineering Software, 2004
An interrogative visualization environment is described for the interactive display and querying ... more An interrogative visualization environment is described for the interactive display and querying of large datasets. The environment combines a web-based intelligent agent facility with a visualization engine. The intelligent agent facility (IAF) incorporates a rule-based expert system for natural-language understanding, voice and text input facilities, a hierarchical clickable command list, an interface for multimodal devices such as menu-based wireless handheld devices and gesture recognition devices, and human-like avatars acting as virtual assistants. The IAF interacts with, and controls, the visualization engine through a TCP/IP network socket interface. The environment enables multiple users using a variety of interaction modes and devices to effectively browse through large amounts of data, focus on and query interesting features, and more easily comprehend and make use of the data. Application of the environment to the visualization of engineering simulations is described.
Pacing and Clinical Electrophysiology, 2019
Patients eligible for primary prevention implantable cardioverter‐defibrillator (ICD) therapy are... more Patients eligible for primary prevention implantable cardioverter‐defibrillator (ICD) therapy are faced with a complex decision that needs a clear understanding of the risks and benefits of such an intervention. In this study, our goal was to explore the documentation of primary prevention ICD discussions in the electronic medical records (EMRs) of eligible patients.
Chest, 2019
Pulmonary hypertension is grouped into 5 broad categories according to the WHO classification. In... more Pulmonary hypertension is grouped into 5 broad categories according to the WHO classification. In rheumatologic disease, the source of elevated pulmonary arterial pressure has many possibilities. Due to the complexity of these patients there remains diagnostic and therapeutic challenges.
American Journal of Gastroenterology, 2019
diarrhea with 5-6 bowel movements/day from last 2-3 months, 30 pound unintentional weight loss in... more diarrhea with 5-6 bowel movements/day from last 2-3 months, 30 pound unintentional weight loss in last 2 months, occasional night sweats. He denied any episodes of flushing. On presentation, vitals were stable. Other labs included CBC-wnl, BUN-25 mg/dl with creatinine of 3 (baseline 2), albumin-2.4, AST-19u/l, ALT-26u/l, ALP-210 u/l, total bilirubin 0.9 mg/dl. Clostridium difficle screen and GI panel were negative. Last colonoscopy, done one month prior to presentation was normal. He was started on Imodium without any relief. Gastroenterology service was consulted for further management. His chromogranin A was found to be 782 (, 93), 5HIAAA was 50 (, 8). He underwent ultrasound of the abdomen for this acute kidney injury which revealed 5.9 3 5.9 3 5.9 cm hyperechoic mass with central decreased echogenicity located within the liver. AFP was 1.1 ng/ml (, 8 ng/ ml), CEA 7.4 ng/ml (3 ng/ml). Meanwhile, he was started on sandostatin which helped a lot with his diarrhea. Further imaging of this abdomen was deferred due to kidney injury. He had previous PET scan done 3-4 years ago revealed increased uptake in liver but were inconsistent of any metastatis. His last abdominal CT scan done 2-3 years ago was negative of any metastasis. Two weeks after his discharge, he was readmitted to intensive care unit (ICU) with septic shock and unfortunately he passed away. DISCUSSION: Carcinoid tumors are relatively slow growing compared to adenocarcinomas of the same site and have a tendency for recurrence. The NANETS Consensus Guideline for the Diagnosis and Management of Neuroendocrine Tumors recommends an office follow up every 6 to12 months for 7 years. Either radiographic (CT/MRI) or endoscopic methods could be used for surveillance. The secretory tumors can be followed up by monitoring the levels of urinary 5-HIAA and serum chromogranin A.
Saudi Pharmaceutical Journal, 2017
Objective: To evaluate the association between the level of vitamin D and glycemic control among ... more Objective: To evaluate the association between the level of vitamin D and glycemic control among patients with diabetes. Research design and method: We analyzed data collected from NHANES 2003-2006. We included only non-pregnant adult diabetic persons 18 years or older. Participants who had vitamin D level less than 20 ng/ml were considered as having vitamin D deficiency. Participants were considered to have a glucose control if the HbA 1c level was less than 7% [53 mmol/L]. We used student's t test to compare the difference in HbA 1c means between people with Diabetes with and without a vitamin D deficiency. We used a multivariate logistic regression model to predict the relationship between glucose control and vitamin D deficiency. We used race/ethnicity, BMI, age, gender, type of diabetic medication used, having health insurance or not, and comorbid conditions (hypertension, anemia, cholesterol, liver disease, and kidney disease) as control variables. Results: The study population included a total of 929 non-institutionalized, non-pregnant, diabetic adult persons. About 57% of patients with diabetes had a vitamin D deficiency. Blacks (non-Hispanic patients) with diabetes had the highest rate of vitamin D deficiency (79%). The unadjusted means of HbA 1c were significantly different between diabetic patients with no vitamin D deficiency and those with a vitamin D deficiency (7.06% [54 mmol/L], 7.56 % [59 mmol/L], respectively, P < 0.0001). Multivariate adjustment showed a small but not significant, increase in odds (11%) of having uncontrolled diabetes in patients with a vitamin D deficiency after adjustment for other factors. Conclusion: Vitamin D deficiency is very common in patients with diabetes. We found no significant association between vitamin D level and glycemic control in patients with diabetes after adjustment for control variables.
Nebraska Law Review, 1970
For the past twelve years Robert Van Pelt has served as Federal District Judge for the District o... more For the past twelve years Robert Van Pelt has served as Federal District Judge for the District of Nebraska. An assessment of his distinguished career at this time would be somewhat premature, as no doubt his schedule will remain quite demanding. However, the retirement of this capable jurist calls for a brief review of his outstanding career.
... Chang..... 3 TECHNOLOGY OVERVIEW MATERIALS AND STRUCTURES..... 13 Structures and Materials Im... more ... Chang..... 3 TECHNOLOGY OVERVIEW MATERIALS AND STRUCTURES..... 13 Structures and Materials Impasse?, William A. Mrazek..... 15 Structures and Materials (State of the Art1960), George Gerard..... 23 ...
Journal of the College of Physicians and Surgeons--Pakistan : JCPSP, 2005
To assess the risk factors associated with development of ventilator associated pneumonia (VAP). ... more To assess the risk factors associated with development of ventilator associated pneumonia (VAP). A case control study. Intensive Care Unit (ICU) at the Aga Khan University Hospital, Karachi, between January 1999 and June 2000. All patients with assisted mechanical ventilation were assessed for the development of VAP. Risk factors associated with development of VAP were determined. Adult patients who developed pneumonia, 48 hours after ventilation, were called cases while those who did not develop pneumonia were called controls. Seventy (28%) out of 250 mechanically ventilated patients developed VAP (rate of VAP was 26 cases per 1000 ventilator days). Shock during first 48 hours of ventilation (odds ratio (OR), 5.95; 95% confidence interval (CI), 2.83-12.52), transport out of ICU during mechanical ventilation (OR, 6.0; 95% CI, 2.92-12.37), re-intubation (OR, 4.23; 95% CI, 2.53-9.85), prior episode of aspiration of gastric content (OR, 3.07; 95% CI, 1.35-7.01), and use of antibiotics ...
Advances in Engineering Software, 2014
38th Structures, Structural Dynamics, and Materials Conference, 1997
The results of a detailed study of the nonlinear response of curved sandwich panels with composit... more The results of a detailed study of the nonlinear response of curved sandwich panels with composite face sheets and subjected to a temperature gradient through the thickness combined with mechanical loadings are presented. The analysis is based on a first-order sheardeformation Sanders-Budiansky type theory with the effects of large displacements, moderate rotations, transverse shear deformation and laminated anisotropic material behavior included. A mixed formulation is used with the fundamental unknowns consisting of the generalized displacements and the stress resultants of the panel. The nonlinear displacements, strain energy, principal strains, transverse shear stresses, transverse shear strain energy density, and their hierarchical sensitivity coefficients are evaluated. The hierarchical sensitivity coefficients measure the sensitivity of the nonlinear response to variations hi the panel parameters, the effective properties of the face sheet layers and the core, and the micromechanical parameters. Numerical results are presented for cylindrical panels subjected to combined pressure loading, edge shortening or extension, edge shear and a temperature gradient through the thickness. The results show the effects of variations in the loading and the panel aspect ratio, on the nonlinear response and its sensitivity to changes in the various panel, effective layer and micromechanical parameters. Nomenclature
Applied Physics A, 2013
Atomic layer deposited thin HfO 2 film has been demonstrated to act as a pore-sealing layer and a... more Atomic layer deposited thin HfO 2 film has been demonstrated to act as a pore-sealing layer and a Cu diffusion barrier layer used in porous low-k dielectrics. This study investigates the effect of annealing temperature on the electrical characteristics and reliability of the dielectric stacks with HfO 2 and porous low-k films. The experimental results reveal that annealing improved electrical performance and reliability, but increased the dielectric constant. However, the resulting dielectric constant of the annealed HfO 2 /porous low-k dielectric stacks following oxygen plasma treatment was still lower than that of the dielectric stacks without annealing, indicating that annealing improved the properties of HfO 2 /porous low-k dielectric stacks. Annealing at 400°C improved electrical characteristics, reliability, and Cu barrier performance more than did annealing at 600°C because at 600°C annealing, the grain boundaries of the crystallized HfO 2 film provide a conduction path and cause the breakage of the porous low-k film. However, the HfO 2 /porous low-k dielectric stacks that were annealed at 600°C exhibited greater resistance against damage by oxygen plasma.