Simulation for enhancement in sensitivity of chalcogenide glasses-based fibre optic evanescent absorption sensor for malignant tissue detection

2020 ◽  
Vol 12 ◽  
Author(s):  
Ritesh Kumar Singh ◽  
Adarsh Chandra Mishra ◽  
Pooja Lohia ◽  
D.K. Dwivedi
Keyword(s):  
Evanescent Wave ◽  
Chalcogenide Glasses ◽  
Biological Tissues ◽  
Biological Species ◽  
Primary Objective ◽  
Effect Of Temperature ◽  
Refractive Indices ◽  
Core Radius ◽  
Source Illumination ◽  
Study Results

Background: Refractive index determination of biological tissues is a challenging issue. Many biological species also show vibrational signature in infrared domain. The chalcogenide-based glasses can be used to make the fiber optic evanescent wave sensors for detection of analyte. Objectives: The primary objective is to study the effect of various parameters on the sensitivity of chalcogenide glass-based evanescent wave sensor for biological tissue detection. Methods: An evanescent wave sensor has been proposed with collimated source illumination and uniform tapering. The chalcogenide materials are chosen such that the weakly guiding approximation could be followed. Complex refractive indices of liver tissue samples have been taken for the analysis of sensitivity via method of evanescent absorption coefficient. Equations for sensitivity have been solved analytically using MATLAB software. Results: The simplification of the formula for sensitivity leads to the inference that the sensitivity is a function of core radius, refractive indices of sample tissues and wavelength used. Moreover, since the refractive indices of the materials are also a function of temperature, therefore a change in temperature results into change in the profile of guiding mode. Hence the effect of temperature must also be observed. The initial simulation parameters are taken; core radius 100 µm, sensing length 4 cm and wavelength 1.0 µm. In the NIR region we have a better sensitivity of detection for all the tissues samples and the risk of photodamage of the biosamples is reduced to a good extent. It has been found that sensitivity decreases with wavelength and core radius whereas increases with temperature. It has also been shown that sensitivity is found to be better with collimated in comparison with diffused source. Conclusion: The comparative study results that one should operate at shorter NIR region of wavelength for higher sensitivity. The collimated source illumination should be preferred over diffused one for launching the light within the fiber to have high sensitivity. Further, length of sensing region should be larger but the fiber core radius should be smaller. The proposed biosensor is robust and can also be used many times if the probe (sensing region) is cleaned properly. Moreover, a small amount of analyte is enough for the detection. Thus, the proposed sensor is very useful for bio-medical applications with its high performance, accuracy and robustness.

scholarly journals Effect of Temperature and Germania on the Performance of Germania Doped Silica Fiber Raman Scattering Amplifier

2022 ◽  
Author(s):  
B. M. El-den ◽  
Adel zaghloul
Keyword(s):  
Pump Power ◽  
Gain Coefficient ◽  
Effect Of Temperature ◽  
Refractive Indices ◽  
Raman Gain ◽  
Gain Saturation ◽  
Core Radius ◽  
Signal Wavelength ◽  
Amplifier Gain ◽  
Better Than

Abstract The Raman gain coefficient, the attenuations at signal and pump wavelengths and the refractive indices of both core and cladding of silica doped Germania optical fiber are functions of the Germania ratio, temperature and wavelengths. The Raman amplifier gain increases with Germania ratio but it decreases with temperature. Also, Raman gain either increases or decreases with signal wavelength. As the fiber core radius increases, the Raman gain decreases. The gain distribution through the amplifier length of dual pumps with power divided ratio (S=0.5) is better than that for the forward pump amplifier and the backward pump amplifier. The forward pump has a maximized gain but the backward pump has a minimized gain, while the dual pumps have both the maximum and minimized gains. The final amplifier gain for the three kinds of pumps with the same pump power (Pp) is equally.The pump wavelength (λp=1.4553μm) gives the biggest Raman gain at the center of wideband signal wavelength (λs=1.50 to 1.60μm). With λp =1.48μm, the gain increases with λs until λs=1.57μm and after that the gain decreases with λs and so with the above three kinds of pumps, gain fluctuations over the band wavelength of signal. The threshold pump power and gain saturation are studied.

scholarly journals Pharmacokinetics and Safety of Rifamycin SV after Single and Multiple Doses of MMX® Modified Release Tablets in Healthy Male and Female Volunteers

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 167
Author(s):  
Andrea Francesco Daniele Di Stefano ◽  
Milko Massimiliano Radicioni ◽  
Angelo Vaccani ◽  
Alessandro Mazzetti ◽  
Luigi Maria Longo ◽  
...  
Keyword(s):  
Dose Regimen ◽  
Multiple Dose ◽  
Daily Intake ◽  
Pharmacokinetic Profile ◽  
Primary Objective ◽  
Systemic Absorption ◽  
Modified Release ◽  
Post Dose ◽  
Rifamycin Sv ◽  
Study Results

The primary objective of this single- and multiple-dose pharmacokinetic study was the investigation of rifamycin SV’s pharmacokinetic profile in plasma and urine. All the 18 enrolled healthy men and post-menopausal women received modified release tablets containing 600 mg of the oral non-absorbable antibiotic, rifamycin SV, according to a multiple dose regimen: one tablet three times a day (daily intake: 1800 mg) for 14 consecutive days. Blood sampling and urine collection were performed up to 24 h post-dose after the first dose on Days 1 and 7. On average, on Day 1, Cmax,0–24 was 5.79 ± 4.24 ng/mL and was attained in a median time of 9 h. On Day 7, all the subjects had quantifiable levels of rifamycin SV in plasma at each sampling time. After a peak concentration attained 2 h post-dose (mean ± SD concentration: 10.94 ± 16.41 ng/mL), rifamycin SV decreased in plasma to levels similar to those of Day 1. The amounts of rifamycin SV excreted in urine paralleled the plasma concentration at the corresponding times. On Day 1, the total amount excreted in urine was 0.0013%, and was 0.0029% on Day 7. The study results confirmed those of the previous Phase I study: the systemic absorption of rifamycin SV was also proved negligible after 7 days of the 600 mg t.i.d. dose regimen of the newly formulated tablets, currently under development for the treatment of several small and large intestinal pathologies, including diarrhea-predominant irritable bowel syndrome, hepatic encephalopathy, and others. Registered at ClinicalTrials.gov with the identifier NCT02969252, last updated on 26JAN18.

Optimizing chair time in infusion centers using intravenous cetirizine premedication for the prevention of hypersensitivity infusion reactions.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e13508-e13508
Author(s):  
Julio Antonio Peguero ◽  
Ahmed Ayad ◽  
Stacia Young-Wesenberg ◽  
Teresa Yang ◽  
Janine North ◽  
...  
Keyword(s):  
Controlled Trial ◽  
Quality Care ◽  
Primary Objective ◽  
Double Blind ◽  
Acute Urticaria ◽  
Number Of Patients ◽  
Study Results ◽  
Secondary Endpoints ◽  
Infusion Reactions ◽  
Anti Cd20

e13508 Background: Oncology infusion centers are increasingly focused on improving operational efficiencies and patient satisfaction, while maintaining quality care. One key component is optimizing chair time, which has been especially important for patient safety during the COVID-19 pandemic to reduce risk of transmission. Many infusions require antihistamine premedication to reduce the risk of hypersensitivity infusion reactions (IRs). The two IV options are IV diphenhydramine and IV cetirizine, which have a quicker onset than oral options and can be administered IV push. In treating acute urticaria, IV cetirizine was shown to be comparable to IV diphenhydramine, with fewer side effects, and it may be effective for preventing IRs with improved chair time. Methods: A randomized, double-blind phase 2 study evaluating premedication with single dose IV cetirizine 10 mg versus IV diphenhydramine 50 mg was conducted in 34 patients receiving paclitaxel, rituximab, its biosimilar or obinutuzumab (first cycle, retreatment after 6 months or with persistent IRs). The primary objective was the incidence of IRs after premedication. Secondary endpoints included sedation due to antihistamines and time to readiness for discharge. Sedation was reported by patients on a scale of 0-4 (0 = none to 4 = extremely severe). No formal statistical analyses were planned given the exploratory nature of the study. Results: Adults primarily with cancer (n = 31 [91%]) were enrolled during the COVID-19 pandemic, from March 25 to November 23, 2020. The median age was 65 and 67 years in the IV cetirizine and diphenhydramine groups, respectively. The number of patients with IRs was 2/17 (11.8%) with IV cetirizine versus 3/17 (17.6%) with IV diphenhydramine. The mean sedation score in the IV cetirizine group compared to the IV diphenhydramine group was lower at all time points, including at discharge (0.1 vs 0.4, respectively). Mean time to discharge was 24 minutes less with IV cetirizine (4.3 hours [1.5]) versus IV diphenhydramine (4.7 hours [1.2]). This difference was greater (30 minutes less) in those ≥65 years of age (4.4 [1.3] vs 4.9 [1.0] hours). Regardless of whether patients received paclitaxel (n = 9) or an anti-CD20 (n = 25), patients had less chair time when premedicated with IV cetirizine. There were fewer treatment-related adverse events (AEs) with IV cetirizine (2 events) than with IV diphenhydramine (4 events). Conclusions: This was the first randomized, controlled trial evaluating IV antihistamine premedication for IRs and chair time. It was shown that IV cetirizine can prevent IRs, with less sedation, fewer related AEs and reduced chair time compared to IV diphenhydramine. This improves infusion center operations and patient experience. Clinical trial information: NCT04189588.

scholarly journals The possibilities of using group regression in the analysis of the diameter structure development in selection forests of Tara

2002 ◽  
pp. 79-89 ◽  
Author(s):  
Slobodanka Mitrovic ◽  
Stanisa Bankovic
Keyword(s):  
Mathematical Model ◽  
Future Development ◽  
Functional Dependence ◽  
Primary Objective ◽  
Structure Development ◽  
Study Results ◽  
The Future ◽  
Diameter Structure ◽  
Group Regression ◽  
Diameter Classes

Based on the presented study results, it can be concluded that the distribution of tree numbers per diameter degrees (diameter structure) in the four measurements of the compartments 51 and 75, did not change. It was also concluded that one functional dependence could be applied for both compartments N=e5,9?e?0,39*d The result of the above is that also in the following measurements, the diameter structure will remain unchanged, in cases of the same or similar selection cuttings both by the scope and by the distribution of felled trees per diameter classes The primary objective of this type of study is to predict, based on a mathematical model of diameter structure development, effect of the scope of selection cuttings and the number of recruitments on the diameter structure, and the simulation of growth, the distribution of trees per diameter classes in the following measurement or measurements, i.e. to foresee the future development of selection stands.

scholarly journals Effect of Temperature and Pyrolysis Time in Liquid Smoke Production from Dried Water Hyacinth

2020 ◽  
Vol 9 (1) ◽  
pp. 164-171
Keyword(s):  
Refractive Index ◽  
Water Hyacinth ◽  
Effect Of Temperature ◽  
Refractive Indices ◽  
Total Acid ◽  
Temperature Variations ◽  
Liquid Smoke ◽  
Time Variations ◽  
Pyrolysis Reactor ◽  
Time Variables

This study aimed to investigate the use of water hyacinth to produce liquid smoke. The study observes the temperature and time variables of yield, pH, density, and refractive index in the production of liquid smoke from water hyacinth. The sequence of the work is as follows: first, water hyacinth was cut into 5 cm sections and then sun-dried for 2–3 d, depending on the weather. Next, 550 g of dried water hyacinth was added to the pyrolysis reactor. The temperature variations were 200°C, 400°C, and 600°C, and the time variations were 1, 4, and 7 h. As a result, liquid smoke was produced with varying yield, pH, densities, and refractive indices. The best results in this research are liquid smoke pyrolysis at a temperature of 400°C and 4 h with the acquisition of a yield of 93 mL, pH 2–4, a density of 1.080,8 gr/mL, and a refractive index of 1.339,6, with chemical component 41.45% total acid, 2.44% phenol and 56.10% carbonyl.

scholarly journals Rebleeding in Variceal and Nonvariceal Gastrointestinal Bleeds in Cirrhotic Patients Using Vitamin K1: The LIVER-K Study

2020 ◽  
Vol 73 (1) ◽  
Author(s):  
Duane Bates ◽  
Jenny Edwards ◽  
Ashten Langevin ◽  
Adrian Abu-Ulba ◽  
Faizath Yallou ◽  
...  
Keyword(s):  
Primary Objective ◽  
Prescribing Patterns ◽  
Varices Œsophagiennes ◽  
Vitamin K1 ◽  
Grand Nombre ◽  
Gastroesophageal Varices ◽  
Varices Oesophagiennes ◽  
Study Results ◽  
Significant Difference ◽  
Étude Multicentrique

ABSTRACTBackground: Gastroesophageal varices are the most common cause of upper gastrointestinal bleeding (UGIB) in patients with cirrhosis. Vitamin K1 is commonly administered to patients presenting with UGIB andelevated international normalized ratio, despite limited evidence to support this practice.Objectives: The primary objective was to describe the incidence of rebleeding within 30 days after vitamin K1 administration in patients with cirrhosis and UGIB. The secondary objective was to describe prescribing patterns for vitamin K1.Methods: This retrospective, descriptive multicentre study involved patients with cirrhosis and UGIB who were admitted to any of the 4 adult acute care hospitals in Calgary, Alberta, from January 1, 2014, to December 31, 2016. Patients were divided into 2 groups: those who received vitamin K1 and those who did not.Results: A total of 370 patients met the inclusion criteria, of whom 243 received vitamin K1 and 127 did not. Baseline characteristics were similar between the groups. Greater proportions of patients in the vitamin K1 group received transfusions of packed red blood cells, fresh frozen plasma, platelets, cryoprecipitate, or prothrombin concentrate during their admissions. There was no significant difference in the duration of octreotide and pantoprazole infusions. Among patients in the vitamin K1 group, there were more admissions to the intensive care unit and longerlengths of stay. More patients in the no vitamin K1 group had esophageal varices evident on endoscopy that required endoscopic treatment. Forty of the patients (16.5%) in the vitamin K1 group and 7 (5.5%) in the novitamin K1 group had rebleeding within 30 days of the initial bleed. The median total vitamin K1 dose administered was 25 mg.Conclusions: The study results suggest that vitamin K1 does not reduce the incidence of rebleeding within 30 days of the initial bleed in patients with cirrhosis and UGIB.RÉSUMÉContexte : Les varices oesophagiennes sont la cause la plus fréquente de l’hémorragie gastro-intestinale supérieure (HGIS) parmi les patients atteints de cirrhose. On administre communément de la vitamine K1 aux patientsprésentant une HGIS et dont la mesure du rapport international normalize (RIN) est élevée, malgré le manque de preuves soutenant cette pratique.Objectifs : L’objectif principal consistait à décrire la fréquence de la reprise du saignement dans les 30 jours après l’administration de la vitamine K1 à des patients atteints de cirrhose et de HGIS. L’objectif secondaire consistait à décrire les schémas de prescription de la vitamine K1.Méthode : Cette étude multicentrique, descriptive et rétrospective comprenait des patients atteints de cirrhose et de HGIS, ayant été admis à n’importe lesquels des quatre hôpitaux de soins actifs pour adultes de Calgary, Alberta, du 1er janvier 2014 au 31 décembre 2016. Les patients étaient répartis en deux groupes : ceux ayant reçu de la vitamin K1 et ceux n’en ayant pas reçu.Résultats : Le nombre total de 370 patients correspondait aux critères d’inclusion. Parmi ceux-ci, 243 avaient reçu de la vitamine K1 et 127 n’en n’avaient pas reçu. Les caractéristiques de base étaient similaires entre lesgroupes. Un plus grand nombre de patients du groupe « Vitamine K1 » avaient reçu une transfusion d’un concentré de globules rouges, de plasma frais congelé, de plaquettes, de cryoprécipité ou de concentré de prothrombine au cours de leur séjour hospitalier. On n’a noté aucune différence significative dans la durée des injections de pantoprazole et d’octréotide. Le nombre d’admissions de patients du groupe « Vitamine K1 » à l’unité de soins intensifs était plus élevé et le séjour de ceux-ci était plus long. L’endoscopie a montré qu’un plus grand nombre de patients du groupe « Sans vitamine K1 » présentaient des varices oesophagiennes nécessitant un traitement endoscopique. Dans les 30 jours après le saignement initial, quarante (16,5 %) patients du groupe « Vitamine K1 » et 7 (5,5 %) du groupe « Sans vitamine K1 » ont subi une nouvelle hémorragie. La dose moyenne totale de vitamine K1 administrée était de 25 mg.Conclusions : Les résultats de l’étude tendent à démontrer que la vitamin K1 ne réduit pas la fréquence de la reprise du saignement dans les 30 jours qui suivent le saignement initial parmi les patients atteints de cirrhose et de HGIS.

scholarly journals Achieving High-Speed Retraction in a Stretchable Hydrogel

2020 ◽  
Author(s):  
Rosa Maria Badani Prado ◽  
Satish Mishra ◽  
Buckston Morgan ◽  
Rangana Wijayapala ◽  
Seyed Meysam Hashemnejad ◽  
...  
Keyword(s):  
High Speed ◽  
Biological Tissues ◽  
Biological Species ◽  
Vital Role ◽  
Polypropylene Glycol ◽  
Glycol Diacrylate ◽  
Mantis Shrimp ◽  
Power Amplification ◽  
Short Period ◽  
Very High

Many biological species apply the power amplification mechanism for locomotion, feeding, and protection. In power amplification, a biological system rapidly releases stored-energy by achieving a very high velocity over a short period of time, resulting in high power output. Such power amplification allows insects such as locust to jump and Mantis shrimp to kill prey by its appendage strike. Biological elastomeric polymers such as resilin play a vital role in the power amplification process because of their high stretchability and resilience. In synthetic materials, although<br>crosslinked rubbers display high stretchability and resilience, such is difficult to achieve in the water-containing systems such as in hydrogels, commonly considered materials for mimicking biological tissues. Here, we have used a simple free-radical polymerization of acrylic acid (AAc), methacrylamide (MAAm), and polypropylene glycol diacrylate (PPGDA) to obtain hydrogels. In these gels, the polymerized AAc and MAAm act as hydrophilic blocks and PPG as hydrophobic, and the gel structure resemble that of resilin consisting of hydrophilic and hydrophobic components. The bioinspired gels display very high stretchability, as high as eight times the original length, and greater than 90% resilience. In addition, the gel samples can reach a retraction velocity of 16 m/s with an acceleration of 4X10^3 m/s2. These values are similar or better than those observed in water containing biological systems, such as appendage strikes in Mantis shrimp, etc. To the best of our knowledge, such performance has not been reported in the<br>literature for any water containing networks.

scholarly journals Characterisation of Biological Materials at THz Frequencies by Attenuated Total Reflection: Lard

2020 ◽  
Vol 10 (23) ◽  
pp. 8692
Author(s):  
Zoltan Vilagosh ◽  
Alireza Lajevardipour ◽  
Dominique Appadoo ◽  
Soon Hock Ng ◽  
Saulius Juodkazis ◽  
...  
Keyword(s):  
Penetration Depth ◽  
Evanescent Wave ◽  
Total Internal Reflection ◽  
Complex Refractive Index ◽  
Biological Tissues ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Frustrated Total Internal Reflection ◽  
Model Sample ◽  
Difference Time

The penetration depth of an evanescent wave in Attenuated Total Reflection (ATR) is dependent on the wavelength of the radiation utilised. At THz frequencies, the penetration depth into biological tissues is in the order of 0.1 to 0.5 mm; rendered pig lard was used as a model sample in this study. A method for the direct measurement of the evanescent wave penetration depth is presented which allows for the estimation of the dispersion of the complex refractive index by using the reflection of the evanescent wave from varying sample depths. The method employs frustrated total internal reflection, and has been demonstrated by using the THz/Far-IR beamline at the Australian synchrotron, and modelled using finite difference time domain (FDTD) simulations.

A Study on the Effect of the Temperature on Mechanical Properties of H90 Copper Strip

2019 ◽  
Vol 950 ◽  
pp. 65-69
Author(s):  
Sun Fei ◽  
Xu Cheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Effect Of Temperature ◽  
Basic Material ◽  
Copper Strip ◽  
Study Results ◽  
Different Temperatures ◽  
Strip Test

In order to study the effect of temperature on the mechanical properties of H90 copper strip material, the H90 copper strip test pieces were heated to different temperatures (20~600 °C) for tensile test; the yield strength, tensile strength, elastic modulus and elongation of H90 copper strip at different temperatures were obtained. Based on the test results, the empirical models of yield strength, tensile strength, elastic modulus of H90 copper strip at high temperature were established; the test showed that, with the increase of temperature, the yield strength, tensile strength and elastic modulus of H90 copper strip decreased greatly, and the elongation after fracture first increased-decreased-increased at 20~600 °C. The study results in this paper provide basic material data for analyzing the effect of temperature on the continuous firing of firearms and other weapons.

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