A simple novel device for air sampling by electrokinetic capture.

BackgroundA variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable.ResultsAn air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrode assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87 %, with the reference filter taken as "gold standard." Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air.ConclusionsThis work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. The performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing

A simple novel device for air sampling by electrokinetic capture

© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Microbiome 3 (2015): 79, doi:10.1186/s40168-015-0141-2.A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrode assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87 %, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. The performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.This work was partly supported by Breakout Labs, a program of the Thiel Foundation, and partly from personal funds from Julian Gordon and Prasanthi Gandhi. This work was supported in part by the US Dept. of Energy under Contract DE-AC02-06CH11357

A Study of fine needle aspiration of thyroid lesion by the 2017 bethesda system for reporting thyroid cytopathology and their correlation with thyroid function test - A prospective study

Introduction: Fine needle aspiration cytology is initial investigation for the diagnosis of thyroid lesions. The revised 2017 Bethesda system for reporting thyroid cytopathology provides a category based reporting system for FNAC of thyroid lesions. Thyroid function test also plays important role to manage patients. The present study was undertaken to categorise all the thyroid lesions according to Bethesda system into 6 categories and correlate with Thyroid function test. Material and Methods: The study period was from January 2020 to June 2021. During the study period, a total of 100 cases of thyroid fine needle aspirations were collected and categorized according to “The 2017 Bethesda System for Reporting Thyroid Cytopathology”. It was easy to classify the result in 6 categories. Later these cases were followed up with their thyroid profile test. Result: A total of 100 cases were studied, out of which 83 patients were females and 17 were males, with Female to Male ratio of 4.8:1. with a mean age of 35.96 years. Among 100 cases, non neoplastic category II lesions were the major proportion constituting 79%, category I unsatisfactory smears were 1%, category III 0%, next highest percentage of cases were in category IV with 14%, category V had 1% cases and category VI had 5% of cases. Patients with hypothyroid were 23%, patients with euthyroid were 68% and 9% patients were in hyperthyroid condition. Conclusion: The revised 2017 Bethesda system is an excellent reporting system for thyroid FNA. Both Bethesda categories and TFT are independent variables and there is no correlation between the

Contrast Mechanisms on Nanoscale Subsurface Imaging in Ultrasonic AFM: Scattering of Ultrasonic Wave and Contact Stiffness of Tip-Sample

Ultrasonic atomic force microscopy (AFM) and its associated derivatives are nondestructive techniques that can elucidate subsurface nanoscale structures and properties. Despite the usefulness of these techniques, the physical contrast mechanisms responsible for the reported subsurface features observed in ultrasonic AFM are not well defined. In this study, we present a comprehensive model combining ultrasonic wave scattering and tip–sample contact stiffness to better reproduce the experimentally measured phase variations over subsurface features in two model systems. These model systems represent the two extreme sample types typically imaged by ultrasonic AFM, one being a hard material and the other a soft polymeric material. The theoretical analysis presented and associated comparisons with experimental results suggest that the image contrast depends on the combination of two contrast mechanisms: the perturbation of the scattered ultrasonic waves and the local variation of the contact stiffness at the tip–sample contact. The results of this study open up a new door for the depth estimation of buried nanoscale features into hard (engineering structures) and soft (polymers and biological structures) materials, and eventually lead to non-invasive, high-resolution 3D nano-tomography by ultrasonic AFM