Filtration and Particle Count Classifications

Author(s):  
Charles Moyer
Keyword(s):  
1965 ◽  
Vol 13 (02) ◽  
pp. 428-438 ◽  
Author(s):  
K Reber ◽  
A Studer

SummaryThis is a comparative study of the methods described by H. P. Wright and O’Brien for determining the adhesiveness of thrombocytes. An attempt is made to characterize and statistically correlate both techniques. With the aid of a Coulter Counter for thrombocyte counts, a normal range is presented for human, rat, and rabbit blood. Anticoagulants used are sodium citrate and Heparin.The influence of Cocaine and the Serotonin antagonist Ro 3-0837 was studied on these same substrates, to determine a pharmacological interference with results of either Wright’s test or O’Brien’s. Both drugs are found to induce a statistically significant increase in the “thrombocyte count” as compared to the corresponding controls. These effects are not real but to be attributed to an increase in particle count due to thrombocyte fragmentation as a consequence of drug application. There is no evidence for the claim that these drugs decrease the adhesiveness of thrombocytes.Numerical results of both tests often show a high and statistically significant correlation, especially following the addition of Ro 3-0837. Such is not true of individual blood samples to which no drug has been added. Evidentally, both tests are not specific for the same characteristic of normal blood platelets. But, when Ro 3-0837 is added, the breakdown of unstable platelets is induced; and the corresponding increase in count of thrombocyte fragments is expressed by both tests in the same fashion.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 295-299
Author(s):  
Debbie L Teodorescu ◽  
Stephen Okajima ◽  
Asad Moten ◽  
Mike H M Teodorescu ◽  
Majed El Hechi ◽  
...  

ABSTRACT Introduction Scarcity of operating rooms and personal protective equipment in far-forward field settings make surgical infections a potential concern for combat mortality and morbidity. Surgical and transport personnel also face infectious risks from bodily fluid exposures. Our study aimed to describe the serial, proof-of-concept testing of the SurgiBox technology: an inflatable sterile environment that addresses the aforementioned problems, fits on gurneys and backpacks, and drapes over incisions. Materials and Methods The SurgiBox environmental control unit and inflatable enclosure were optimized over five generations based on iterative feedback from stakeholders experienced in surgery in austere settings. The airflow system was developed by analytic modeling, verified through in silico modeling in SOLIDWORKS, and confirmed with prototype smoke-trail checking. Particulate counts evaluated the enclosure’s ability to control and mitigate users’ exposures to potentially infectious contaminants from the surgical field in various settings. SurgiBox enclosures were setup over a mannequin’s torso, in a configuration and position for either thoracic or abdominal surgery. A particle counter was serially positioned in sternotomy and laparotomy positions, as well as bilateral flank positions. This setup was repeated with open ports exposing the enclosure to the external environment. To simulate stress scenarios, sampling was repeated with enclosure measurements during an increase in external particulate concentration. Results The airflow technology effectively kept contaminants away from the incision and maintained a pressure differential to reduce particle entry. Benchtop testing demonstrated that even when ports were opened or the external environment had high contaminant burden, the enclosed surgical field consistently registered 0 particle count in all positions. Time from kit opening to incision averaged 54.5 seconds, with the rate-limiting step being connecting the environmental control unit to the enclosure. The portable kit weighted 5.9 lbs. Conclusions Analytic, in silico, and mechanical airflow modeling and benchtop testing have helped to quantify the SurgiBox system’s reliability in creating and maintaining an operating room-quality surgical field within the enclosure as well as protecting the surgical team outside the enclosure. More recent and ongoing work has focused on specifying optimal use settings in the casualty chain of care, expanding support for circumferential procedures, automating airflow control, and accelerating system setup. SurgiBox’s ultimate goal is to take timely, safe surgery to patients in even the most austere of settings.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Christine L. Farnsworth ◽  
Peter O. Newton ◽  
Eric Breisch ◽  
Michael T. Rohmiller ◽  
Jung Ryul Kim ◽  
...  

Study Design. Combinations of metal implants (stainless steel (SS), titanium (Ti), and cobalt chrome (CC)) were placed in porcine spines. After 12 months, tissue response and implant corrosion were compared between mixed and single metal junctions. Objective. Model development and an attempt to determine any detriment of combining different metals in posterior spinal instrumentation. Methods. Yucatan mini-pigs underwent instrumentation over five unfused lumbar levels. A SS rod and a Ti rod were secured with Ti and SS pedicle screws, SS and Ti crosslinks, SS and CC sublaminar wires, and Ti sublaminar cable. The resulting 4 SS/SS, 3 Ti/Ti, and 11 connections between dissimilar metals per animal were studied after 12 months using radiographs, gross observation, and histology (foreign body reaction (FBR), metal particle count, and inflammation analyzed). Results. Two animals had constructs in place for 12 months with no complications. Histology of tissue over SS/SS connections demonstrated 11.1 ± 7.6 FBR cells, 2.1 ± 1.7 metal particles, and moderate to extensive inflammation. Ti/Ti tissue showed 6.3 ± 3.8 FBR cells, 5.2 ± 6.7 particles, and no to extensive inflammation (83% extensive). Tissue over mixed components had 14.1 ± 12.6 FBR cells and 13.4 ± 27.8 particles. Samples surrounding wires/cables versus other combinations demonstrated FBR (12.4 ± 13.5 versus 12.0 ± 9.6 cells, P = 0.96), particles (19.8 ± 32.6 versus 4.3 ± 12.7, P = 0.24), and inflammation (50% versus 75% extensive, P = 0.12). Conclusions. A nonfusion model was developed to study corrosion and analyze biological responses. Although no statistical differences were found in overlying tissue response to single versus mixed metal combinations, galvanic corrosion between differing metals is not ruled out. This pilot study supports further investigation to answer concerns when mixing metals in spinal constructs.


2013 ◽  
Vol 251 (1) ◽  
pp. 19-26 ◽  
Author(s):  
M. RÖDING ◽  
H. DESCHOUT ◽  
K. BRAECKMANS ◽  
M. RUDEMO

2011 ◽  
Vol 335-336 ◽  
pp. 1035-1038
Author(s):  
Qi Sang ◽  
Shao Jun Wang ◽  
Xue Rong Wang ◽  
Jing Wen Lu

A series of the Yb3+ -doped phosphate laser glass have been prepared under high temperature and different doping content and the fluorescence and absorption spectrum is observed, respectively. The influences of the Yb3+ -doped content on the spectral properties of the glass are analyzed and the optimal mole fraction is 4 %. The emission cross-section and fluorescent lifetime is calculated with McCumber theory. Furthermore, the integrated absorption cross-section, the full width at half maximum of the emission spectra and the laser performance parameters such as least particle count, saturation pump intensity and lowest pump intensity of Yb3+ -doped laser glass is calculated.


2021 ◽  
Vol 891 ◽  
pp. 111-115
Author(s):  
Maradhana Agung Marsudi ◽  
Farah Fitria Sari ◽  
Pandu Mauliddin Wicaksono ◽  
Adinda Asmoro ◽  
Arif Basuki ◽  
...  

In this work, silver nanoparticles have been successfully synthesized using simple and environmentally friendly ‘green synthesis’ method using Indonesian wild honey as mediator. Particle count and size can be optimized by varying the silver nitrate precursor and honey concentration, with the help of sodium hydroxide as pH regulator. Based on X-ray diffraction (XRD) result, crystalline structure of Ag has been confirmed in sample with impurities from AgCl. Based on dynamic light scattering (DLS) and transmission electron microscopy (TEM) results, it was found that the smallest average particles size of AgNPs (117.5 nm from DLS and 11.1 nm from TEM) was obtained at sample with 5% w/v of honey and 0.5 mM of AgNO3.


2013 ◽  
Vol 13 (3) ◽  
pp. 64-67 ◽  
Author(s):  
A. Pasieka ◽  
Z. Konopka

Abstract The method of pressure die casting of composites with AlSi11 alloy matrix reinforced with 10 vol. % of SiC particles and the analysis of the distribution of particles within the matrix is presented. The composite castings were produced at various values of the piston velocity in the second stage of injection, at diverse intensification pressure values, and various injection gate width values. The distribution of particles over the entire cross-section of the tensile specimen is shown. The index of distribution was determined on the basis of particle count in elementary measuring fields. The regression equation describing the change of the considered index was found as a function of the pressure die casting parameters. The conclusion presents an analysis of the obtained results and their interpretation.


Author(s):  
L.A. Shabalinskaia ◽  
V.V. Golovanov ◽  
E.S. Bubnova ◽  
L.V. Milinis

This work is about the possibility of early diagnostics of the technical condition of the main reduction gear in the helicopter. Tribological tests of oil samples taken when testing the operational life are conducted based on the analytical ferrography, morphological analysis, wear particle count, and spectroscopic analysis.


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