scholarly journals Using elastic scattering to determination of diseases via urine samples

2021 ◽  
Vol 8 (4) ◽  
pp. 307-317
Author(s):  
Suleyman Yilmaz ◽  
Keyword(s):  
Transverse Electric ◽  
Scattered Light ◽  
Transverse Magnetic ◽  
Urine Samples ◽  
Optical Parameters ◽  
Test Results ◽  
Standard Data ◽  
Laboratory Test Results ◽  
Back Scattering

<abstract> <p>In diagnosing the urinary tract and related diseases, the problem of light scattering from human urine was examined on the basis of classical electromagnetic theory. Numerical calculations were made for the designed cylindrical model with the help of optical parameters in the literature obtained from the laboratory test results of urine samples. In the designed model, the changes of the scattered intensity of the light from the urine solution according to the size parameter of the particles and the angular distribution of the system (including forward, side and back scattering) in the equatorial plane were obtained, in both transverse electric (TE) and transverse magnetic (TM) of the polarization states of the light. It was observed that the molecular density changes caused by the materials in the urine sample changed primarily the optical parameters and indirectly the intensity distribution of the scattered light. Thus, with the contribution of standard data provided as a result of light scatter calculations from urine samples taken from people with normal and different diseases, it will be easier to diagnose diseases that will be encountered later.</p> </abstract>

Heat Generation in Laser Irradiated Tissue

1989 ◽  
Vol 111 (1) ◽  
pp. 62-68 ◽  
Author(s):  
A. J. Welch ◽  
J. A. Pearce ◽  
K. R. Diller ◽  
G. Yoon ◽  
W. F. Cheong
Keyword(s):  
Heat Source ◽  
Heat Generation ◽  
Near Infrared ◽  
Scattered Light ◽  
Incident Beam ◽  
Accurate Estimation ◽  
Optical Parameters ◽  
Infrared Wavelengths ◽  
Improved Model

Many medical applications involving lasers rely upon the generation of heat within the tissue for the desired therapeutic effect. Determination of the absorbed light energy in tissue is difficult in many cases. Although UV wavelengths of the excimer laser and 10.6 μm wavelength of the CO2 laser are absorbed within the first 20 μm of soft tissue, visible and near infrared wavelengths are scattered as well as absorbed. Typically, multiple scattering is a significant factor in the distribution of light in tissue and the resulting heat source term. An improved model is presented for estimating heat generation due to the absorption of a collimated (axisymmetric) laser beam and scattered light at each point r and z in tissue. Heat generated within tissue is a function of the laser power, the shape and size of the incident beam and the optical properties of the tissue at the irradiation wavelength. Key to the calculation of heat source strength is accurate estimation of the light distribution. Methods for experimentally determining the optical parameters of tissue are discussed in the context of the improved model.

scholarly journals Usefulness of porphyry and amphibolites as a component of concrete for airfield pavements

2018 ◽  
Vol 163 ◽  
pp. 07002
Author(s):  
Małgorzata Linek ◽  
Piotr Nita ◽  
Paweł Wolka ◽  
Wojciech Żebrowski
Keyword(s):  
Bulk Density ◽  
Internal Structure ◽  
Coarse Aggregate ◽  
Cement Matrix ◽  
Physical Parameters ◽  
Hardened Concrete ◽  
Test Results ◽  
Laboratory Test Results ◽  
The Matrix

Coarse aggregate used as part of cement concrete is of primary significance for the obtained parameters of hardened concrete. In case of concretes intended for airfield pavements, the application of granite grit is recommended. Alternative to this type of aggregate in the form of porphyry and amphibolites aggregate was suggested. In order to assess the suitability of different aggregate types for concrete mixes, their bulk density, absorbability, polishing resistance, abrasion and crushing resistance were determined. Also, the internal structure of the suggested aggregates and its influence on changes of hardened concrete composite structure were subject to the assessment. The influence of aggregate type on the structure of cement matrix and contact areas between the matrix and aggregate grains were specified. The observed changes, in case of the internal structure of concretes based on porphyry and amphibolites aggregates, with reference to granite aggregate, resulted in changes of mechanical and physical parameters. Analyses included the determination of bulk density, absorbability, compression, bending and splitting resistance. According to the obtained laboratory test results, the significant influence of the aggregate type applied to the mix on parameters of hardened concrete, with regard to the application thereof to the airfield pavements was proved.

scholarly journals On the potential effect of circadian rhythms of cardiac troponins on the diagnosis of acute myocardial infarction

2021 ◽  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Circadian Rhythms ◽  
Potential Effect ◽  
Diagnostic Process ◽  
Test Results ◽  
Laboratory Test Results ◽  
Increased Sensitivity ◽  
Cardiac Troponins

Methods for the determination of cardiac troponins have been significantly improved, facilitating further advancement of the therapeutic and diagnostic process of the cardiovascular diseases case management. In particular, acceleration of the acute myocardial infarction testing (early diagnostic algorithms: 0-1 h, 0-3 h) enabled earlier detection and choice of the optimal treatment tactics. At the same time, with the increased sensitivity in the laboratory test results interpretation, there emerged a necessity to take into account some additional factors that may affect the concentration of cardiac troponins in blood serum. Several recent studies have reported the existence of circadian rhythms in cardiac troponins. This article aims to discuss the possible mechanisms of how circadian rhythms of cardiac troponins develop and their influence on the diagnosis of acute myocardial infarction.

Determination of the Influence of an Anticorrosive Layer on the Strength of Link Mining Chains/Określenie Wpływu Warstwy Antykorozyjnej Na Wytrzymałość Łańcuchów Ogniwowych – Górniczych

2014 ◽  
Vol 59 (2) ◽  
pp. 367-380
Author(s):  
Mariusz Szot
Keyword(s):  
Laboratory Test ◽  
Complete Analysis ◽  
Test Results ◽  
Operational Parameters ◽  
Modeling Studies ◽  
Laboratory Test Results

Abstract Using link mining chains is related to the proper way of selecting the type of the chain. The operational parameters of the chain are associated with a risk to the employees who operate haulage systems using scraper conveyors. A complete analysis of operational parameters is possible to be made only after relevant tests are performed. The study presents laboratory test results as well as modeling studies which allowed to determine the influence of the anticorrosive protection of the chain’s surface on its operational parameters.

scholarly journals Should clinical laboratories adapt to the reality of chronic kidney disease in the determination of parathyroid hormone?

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
María Luisa González-Casaus ◽  
Pilar Fernández-Calle ◽  
Antonio Buño Soto
Keyword(s):  
Chronic Kidney Disease ◽  
Parathyroid Hormone ◽  
Kidney Disease ◽  
Clinical Laboratory ◽  
Clinical Decisions ◽  
Test Results ◽  
Laboratory Test Results ◽  
The Status ◽  
New Strategies

Abstract Objectives The contribution of the clinical laboratory to diagnostics is increasingly important since a great deal of clinical decisions rely on laboratory test results. Content Parathyroid hormone (PTH) measurement presents a considerable analytical variability due to the heterogeneity of its circulating forms and the antigenic configuration of the different assays commercially available. Such variability may have an impact on pathological conditions associated with significant increases in circulating PTH, as it is the case of chronic kidney disease (CKD). Summary Despite the recent identification of new molecules involved in bone and mineral disorders associated with CKD, such as klotho or the fibroblastic factor 23 (FGF23), nephrologists still base their clinical decisions on PTH concentrations. The problem is that unawareness of these analytical considerations may cause errors in the clinical interpretation of test results. Outlook This systematic review addresses these issues from the clinical laboratory perspective and proposes new approaches related to PTH method selection and result expression. These new strategies will help laboratory medicine specialists and nephrologist better determine the status of CKD patients.

In-situ Determination of Undrained Stress-strain Behavior of Sensitive Clays with the Pressuremeter

1972 ◽  
Vol 9 (3) ◽  
pp. 313-319 ◽  
Author(s):  
B. Ladanyi
Keyword(s):  
Direct Determination ◽  
Strain Curve ◽  
Strength Properties ◽  
Test Results ◽  
Stress Strain ◽  
Strain Behavior ◽  
Expansion Curve ◽  
Laboratory Test Results

A theory originally proposed by Gibson and Anderson (1961) has been extended to enable a direct determination of the whole undrained stress-strain curve of the clay from the pressure-expansion curve obtained in a conventional pressuremeter test.When applied to some pressuremeter tests carried out in Leda clay in the Ottawa area, the method enabled us to determine the undrained stress-strain behavior of the clay up to axial strains of about 20%. It is thought that, when properly performed, the test is able to furnish the data on the undrained stress-strain and strength properties of sensitive clays comparable to the laboratory test results obtained on block samples. Its particular feature is that it also furnishes a true picture of the post-peak strength decrease in terms of shear strain which is usually difficult to obtain by any other type of test.

Computer-Assisted High-Re Solution TEM

1990 ◽  
Vol 48 (1) ◽  
pp. 162-163
Author(s):  
F.A. Ponce ◽  
H. Hikashi
Keyword(s):  
Signal To Noise Ratio ◽  
Accurate Determination ◽  
Computer Software ◽  
Video Camera ◽  
Image Contrast ◽  
Objective Lens ◽  
Computer Assisted ◽  
Optical Parameters ◽  
Astigmatism Correction

The determination of the atomic positions from HRTEM micrographs is only possible if the optical parameters are known to a certain accuracy, and reliable through-focus series are available to match the experimental images with calculated images of possible atomic models. The main limitation in interpreting images at the atomic level is the knowledge of the optical parameters such as beam alignment, astigmatism correction and defocus value. Under ordinary conditions, the uncertainty in these values is sufficiently large to prevent the accurate determination of the atomic positions. Therefore, in order to achieve the resolution power of the microscope (under 0.2nm) it is necessary to take extraordinary measures. The use of on line computers has been proposed [e.g.: 2-5] and used with certain amount of success.We have built a system that can perform operations in the range of one frame stored and analyzed per second. A schematic diagram of the system is shown in figure 1. A JEOL 4000EX microscope equipped with an external computer interface is directly linked to a SUN-3 computer. All electrical parameters in the microscope can be changed via this interface by the use of a set of commands. The image is received from a video camera. A commercial image processor improves the signal-to-noise ratio by recursively averaging with a time constant, usually set at 0.25 sec. The computer software is based on a multi-window system and is entirely mouse-driven. All operations can be performed by clicking the mouse on the appropiate windows and buttons. This capability leads to extreme friendliness, ease of operation, and high operator speeds. Image analysis can be done in various ways. Here, we have measured the image contrast and used it to optimize certain parameters. The system is designed to have instant access to: (a) x- and y- alignment coils, (b) x- and y- astigmatism correction coils, and (c) objective lens current. The algorithm is shown in figure 2. Figure 3 shows an example taken from a thin CdTe crystal. The image contrast is displayed for changing objective lens current (defocus value). The display is calibrated in angstroms. Images are stored on the disk and are accessible by clicking the data points in the graph. Some of the frame-store images are displayed in Fig. 4.

Single-peak-regulation and wide-angle dual-band metamaterial absorber based on hollow-cross and solid-cross resonators

2020 ◽  
Vol 91 (3) ◽  
pp. 30901
Author(s):  
Yibo Tang ◽  
Longhui He ◽  
Jianming Xu ◽  
Hailang He ◽  
Yuhan Li ◽  
...  
Keyword(s):  
Transverse Electric ◽  
Surface Current ◽  
Dielectric Substrate ◽  
Transverse Magnetic ◽  
Metamaterial Absorber ◽  
Absorption Peak ◽  
Dual Band ◽  
Single Peak ◽  
Wide Angle ◽  
Surface Current Density

A dual-band microwave metamaterial absorber with single-peak regulation and wide-angle absorption has been proposed and illustrated. The designed metamaterial absorber is consisted of hollow-cross resonators, solid-cross resonators, dielectric substrate and metallic background plane. Strong absorption peak coefficients of 99.92% and 99.55% are achieved at 8.42 and 11.31 GHz, respectively, which is basically consistent with the experimental results. Surface current density and changing material properties are employed to illustrate the absorptive mechanism. More importantly, the proposed dual-band metamaterial absorber has the adjustable property of single absorption peak and could operate well at wide incidence angles for both transverse electric (TE) and transverse magnetic (TM) waves. Research results could provide and enrich instructive guidances for realizing a single-peak-regulation and wide-angle dual-band metamaterial absorber.

Dispersive Liquid-Liquid Microextraction Based on Ionic Liquid and Spectrophotometric Determination of Bilirubin in Biological Samples

2020 ◽  
Vol 16 (5) ◽  
pp. 652-659
Author(s):  
Asiye A. Avan ◽  
Hayati Filik
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Biological Samples ◽  
Urine Samples ◽  
Spectrophotometric Detection ◽  
Full Color ◽  
Dispersive Liquid Liquid Microextraction ◽  
Urine And Serum ◽  
Liquid Microextraction

Background: An Ionic Liquid-based based Dispersive Liquid-Liquid Microextraction (IL-DLLME) method was not applied to preconcentration and determination of bilirubin. Ionic Liquids (ILs) are new chemical compounds. In recent years, Ionic Liquids (ILs) have been employed as alternative solvents to toxic organic solvents. Due to these perfect properties, ILs have already been applied in many analytical extraction processes, presenting high extraction yield and selectivity for analytes. Methods: In this study, IL-DLLME was applied to biological samples (urine and serum) for the spectrophotometric detection of bilirubin. For bilirubin analysis, the full-color development was based on the reaction with periodate in the presence of hydrochloric acid. The high affinity of bilirubin for the ionic liquid phase gave extraction percentages above 98% in 0.3 M HCl solution. Results: Several IL-extraction parameters were optimized and room temperature ionic liquid 1-butyl- 1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and ethanol were used as extraction and disperser solution. The linear range was found in the range of 0.5-6.0 μM (0.3-3.5 μg mL-1) and the limits of detection of the proposed method was 0.5 μM (0.3 μg mL-1). The proposed method was applied for the preconcentration and separation of trace bilirubin in real urine samples. Also, the recoveries for bilirubin in spiked biological samples (urine and serum) were found to be acceptable, between 95-102%. Conclusion: The proposed IL-DLLMEapproach was employed for the enrichment and determination of trace levels of bilirubin in urine samples using NaIO4 as an oxidizing agent and Uv-vis spectrophotometric detection. The periodate oxidation of bilirubin is rapid, effective, selective, and simple to perform. The method contains only HCl, NaOI4, and an anionic surfactant. The method may be useful for economizing in the consumption of reagents in bilirubin determining. The IL-DLLMEmethod ensures a high yield and has a low toxicity no skin sensitization, no mutagenicity and no ecotoxicity in an aquatic environment since only very low quantities of an IL is required. For full-color formation, no any extra auxiliary reagents are required. Besides, the IL-DLLME technique uses a low-cost instrument such as Uv-vis which is present in most of the medical laboratories.

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