Adsorption of particles on fluid-liquid interfaces

Particles floating on fluid-liquid interfaces are of considerable interest because of their importance in a range of physical applications and biological processes, e.g., self-- assembly of particles at fluid-fluid interfaces resulting in novel nano structured materials, stabilization of emulsions, formation of pollen and insect egg rafts, etc. The aim of this dissertation is to explore the mechanism by which particles are adsorbed at fluid-liquid interfaces. It is shown that the inertia of a particle plays an important role in its motion in the direction normal to a fluid-liquid interface, and in determining the particles adsorption trajectory and orientation in the adsorbed state. Although the importance of inertia diminishes with decreasing particle size, on an air-water interface the inertia continues to be important even when the particle size is as small as a few nanometers. This dissertation also investigates the vertical oscillations of a particle while it is being adsorbed on an interface. The fact that the particle oscillates vertically implies that its behavior is similar to that of an under-damped mass-spring-dashpot system, and that it has characteristic linear and rotational frequencies which depend on the physical properties of the fluids involved and those of the particle. The experimentally measured frequency of oscillation of a particle is in approximate agreement with the frequency calculated analytically, which is noteworthy considering that the latter depends only on the fluid and particle properties, and that there are no adjustable parameters in the analytic expression. It is shown that similarly to an under-damped system, these characteristic frequencies can be excited by an external forcing. When a particle is adsorbed on a fluid-liquid interface it induces a relatively strong transient flow in the liquid which persists for several seconds. For a spherical particle the flow is axisymmetric about the vertical passing through the particle’s center. To visualize this flow, an experiment is designed based of the Particle Image Velocimetry (PIV) technique. The measurements show that the fluid directly below the particle rises up, and near the interface it moves away from the particle. The velocity near the interface is found to be about an order of magnitude larger than in the liquid below the particle

Management Options in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a leading respiratory disease in the world and third leading cause of death in United States. COPD is not recognized as an isolated respiratory disease anymore; in fact it is one of the dreaded diseases with significant systemic involvement and complications. Treatment of COPD requires team work and efforts among physicians, nurses, respiratory therapists and physical therapists. Treatment of patients with frequent exacerbations is a heavy burden on healthcare network. In the last few years, some improvements in the management of COPD have been made, owing to new drugs and management strategies, along with non-pharmacologic treatment of COPD with pulmonary rehabilitation and surgical interventions. Smoking cessation is still the best strategy to prevent COPD and prevent further progression of disease. In this review, we discuss pharmacotherapy of COPD including management of acute exacerbations, pharmacotherapy for smoking cessation and role of vaccination in COPD patients

18 -FDG uptake in pulmonary dirofilariasis

Solitary pulmonary nodules are a common finding on chest radiography and CT. We present the case of an asymptomatic 59-year-old male found to have a 13 mm left upper lobe nodule on CT scan. The patient was asymptomatic and the CT was performed to follow up mediastinal and hilar lymphadenopathy that had been stable on several previous CT scans. He had a history of emphysema and reported a 15 pack-year smoking history. PET-CT was performed which demonstrated mild 18-FDG uptake within the nodule. Given his age and smoking history, malignancy was a consideration and he underwent a wedge resection. Pathological examination revealed a necrobiotic granulomatous nodule with a central thrombosed artery containing a parasitic worm with internal longitudinal ridges and abundant somatic muscle, consistent with pulmonary dirofilariasis. Dirofilaria immitis, commonly known as the canine heartworm, rarely affects humans. On occasion it can be transmitted to a human host by a mosquito bite. There are two major clinical syndromes in humans: pulmonary dirofilariasis and subcutaneous dirofilariasis. In the pulmonary form, the injected larvae die before becoming fully mature and become lodged in the pulmonary arteries

Problematic communications during 2016 fellowship recruitment in internal medicine.

Some internal medicine residency program directors have expressed concerns that their third-year residents may have been subjected to inappropriate communication during the 2016 fellowship recruitment season. The authors sought to study applicants' interpersonal communication experiences with fellowship programs. Many respondents indicated that they had been asked questions that would constitute violations of the National Residency Matching Program (NRMP) Communications Code of Conduct agreement, including how they plan to rank specific programs. Moreover, female respondents were more likely to have been asked questions during interview experiences about other programs to which they applied, and about their family plans. Post-interview communication policies were not made clear to most applicants. These results suggest ongoing challenges for the internal medicine community to improve communication with applicants and uniform compliance with the NRMP communications code of conduct during the fellowship recruitment process

Problematic communications during 2016 fellowship recruitment in internal medicine

Some internal medicine residency program directors have expressed concerns that their third-year residents may have been subjected to inappropriate communication during the 2016 fellowship recruitment season. The authors sought to study applicants’ interpersonal communication experiences with fellowship programs. Many respondents indicated that they had been asked questions that would constitute violations of the National Residency Matching Program (NRMP) Communications Code of Conduct agreement, including how they plan to rank specific programs. Moreover, female respondents were more likely to have been asked questions during interview experiences about other programs to which they applied, and about their family plans. Post-interview communication policies were not made clear to most applicants. These results suggest ongoing challenges for the internal medicine community to improve communication with applicants and uniform compliance with the NRMP communications code of conduct during the fellowship recruitment process