Mucus Transport in the Larger Airway Due to Prolonged Mild Cough: Effect of Serous Fluid and Cilia Beating

Since mucus production and transport is an important defense mechanism of the lower airways, this study focuses on this aspect. In this paper it is assumed that the co-axial flows of mucus and air is taking place in a circular tube representing a larger airway. In the central core, air is assumed to flow under quasi steady state turbulent condition and the mucus layer surrounding this central core is assumed to flow under unsteady laminar condition. The prolonged mild cough is represented by a time dependent pressure gradient function. To consider the effect of serous fluid, it has been assumed that the cilia bed is approximated by a porous matrix within which serous fluid flows following Darcy’s law. Further, the effect of cilia beating has been considered by assuming that a constant mean velocity which is a resultant of effective and recovery stroke is imparted on the serous fluid and this velocity is superimposed on the Darcy flow. For constant porosity of cilia bed and mucus viscosity, it is shown that air and mucus flow rates decrease with increase in serous fluid viscosity. The effect of porosity of cilia bed and cilia beating has been found to increase the air and mucus flow rates. Keywords Cilia Beating; Porous Matrix; Mucus Transport; Circular Model; Prolonged Mild Cough. MSC (2010) No.:76Z0

Localized Charge Transfer Process and Surface Band Bending in Methane Sensing by GaN Nanowires

The physicochemical processes at the surfaces of semiconductor nanostructures involved in electrochemical and sensing devices are strongly influenced by the presence of intrinsic or extrinsic defects. To reveal the surface controlled sensing mechanism, intentional lattice oxygen defects are created on the surfaces of GaN nanowires for the elucidation of charge transfer process in methane (CH4) sensing. Experimental and simulation results of electron energy loss spectroscopy (EELS) studies on oxygen rich GaN nanowires confirmed the possible presence of 2(ON) and VGa-3ON defect complexes. A global resistive response for sensor devices of ensemble nanowires and a localized charge transfer process in single GaN nanowires are studied in situ scanning by Kelvin probe microscopy (SKPM). A localized charge transfer process, involving the VGa-3ON defect complex on nanowire surface is attributed in controlling the global gas sensing behavior of the oxygen rich ensemble GaN nanowires.Comment: 42 pages, 6 figures, Journa

Evolution of an atmospheric boundary layer at a tropical semi-arid station, Anand during boreal summer month of May - A case study

The evolution of an Atmospheric Boundary Layer (ABL) over a semi-arid land station, Anand, (22°35â²N, 72°55â²E, 45.1 m asl) in India, during the summer month of May, is examined using surface meteorological and radiosonde temperature and humidity data collected during LASPEX-97 for a 5-day period from 13-17 May 1997. These 5 days remained undisturbed, and clear sky weather conditions prevailed. However, the data obtained on these days are helpful in understanding the diurnal variation of the ABL over a land station. There are 5 observations per day at an interval of 3 h beginning with 0530 IST. The 0530 IST ascents are chosen to find out the initial ABL heights which exhibit the nocturnal cooling conditions. It is observed from the analysis of θv, θe, θes, q, and P profiles that the nocturnal boundary layer is stable with an inversion close to the ground. The top of an inversion layer is characterized by a θe minimum and a θes maximum. After dawn, the ABL grows to a height of 827 m at 0830 IST. Aloft, a residual layer up to 3200 m is observed. The daytime strong insolation causes formation of an unstable boundary layer close to the ground at 1130 IST with an elevated stable layer between 550 and 930 m. It is only by 1430 IST that the stable layer gets completely wiped out and a convective mixed layer develops up to a height of 3280 m. Lack of moisture inhibits formation of clouds. Hence the ABL at a semi-arid station like Anand is stable in the morning with residual layer aloft and develops into a dry convective boundary layer in the afternoon and evening. Growth of the convective boundary layer (CBL) is observed to be very rapid as it reaches a height up to 3280 m by the afternoon

Guided Prompting in SAM for Weakly Supervised Cell Segmentation in Histopathological Images

Cell segmentation in histopathological images plays a crucial role in understanding, diagnosing, and treating many diseases. However, data annotation for this is expensive since there can be a large number of cells per image, and expert pathologists are needed for labelling images. Instead, our paper focuses on using weak supervision -- annotation from related tasks -- to induce a segmenter. Recent foundation models, such as Segment Anything (SAM), can use prompts to leverage additional supervision during inference. SAM has performed remarkably well in natural image segmentation tasks; however, its applicability to cell segmentation has not been explored. In response, we investigate guiding the prompting procedure in SAM for weakly supervised cell segmentation when only bounding box supervision is available. We develop two workflows: (1) an object detector's output as a test-time prompt to SAM (D-SAM), and (2) SAM as pseudo mask generator over training data to train a standalone segmentation model (SAM-S). On finding that both workflows have some complementary strengths, we develop an integer programming-based approach to reconcile the two sets of segmentation masks, achieving yet higher performance. We experiment on three publicly available cell segmentation datasets namely, ConSep, MoNuSeg, and TNBC, and find that all SAM-based solutions hugely outperform existing weakly supervised image segmentation models, obtaining 9-15 pt Dice gains

Anti-ulcer activity of arachidonic acid (PUFA) oils in different induced ulcer animal models

Background: Ulcers of the lower part of the oesophagus, the stomach and the first part of the duodenum are also known as peptic ulcers. Peptic ulcers can affect people of any age, but they are more common as you get older. There is a focus on research for better tolerated and efficacious anti-ulcer agents.Methods: Effect of anti-ulcer activity of fish oil and Arasco oil was evaluated in different animal models of ulcers i.e. ethanol induced, water immersion and pyloric ligation techniques. The Superoxide dismutase activity in gastric tissue was also ascertained in two groups of animals. The animals received either fish oil (40 µl, PO), Arasco oil (40 µl, PO), omeprazole (20 mg/kg PO) or ranitidine (30 mg/kg PO). The gastro-protection was calculated based on ulcer index, pH and gastric juice volume.Results: The results of this study suggest that poly unsaturated fatty acid (PUFA) contained in fish oil and Arasco oil have moderate anti-ulcer activity although probably lesser in potency than the available anti-ulcer drugs like omeprazole and ranitidine.Conclusion: These  results  have  shown  that  PUFA containing oils  provided  moderate  gastrointestinal  protection  in  all  the induced ulcer models employed. Thus it can be concluded that PUFA containing oils like the Fish oil and Arasco oil have anti-ulcer properties and the mechanisms involved in these actions need to be investigated.

Unique case of central retinal artery occlusion secondary to COVID-19 disease

© 2020 The Authors SARS-COVID-2 has been noted to be associated with neurological symptoms and complications including stroke. Hypercoagulability associated with COVID-19 has been described as a “sepsis-induced coagulopathy” and may predispose to spectrum of thromboembolic events. We present a unique article of isolated central retinal artery occlusion secondary to SARS-COV 2