Evaluation and Comparison of Self-Made and Commercial Calibration Markers for Radiographic Magnification Correction in Veterinary Digital Radiography

2021 ◽  
Author(s):  
Julius Klever ◽  
Anastasia de Motte ◽  
Andrea Meyer-Lindenberg ◽  
Andreas Brühschwein
Keyword(s):  
Surgical Planning ◽  
Good Accuracy ◽  
Use Of Self ◽  
Poor Agreement ◽  
Magnification Factor ◽  
Accuracy And Precision ◽  
Radiographic Magnification ◽  
Flexible Segment ◽  
Flexible Arms ◽  
Calibration Techniques

Abstract Introduction Magnification error is always present in radiography and calibration is necessary, if high accuracy is required in pre-surgical planning. The goal of this study was to verify the use of self-made markers and calibration techniques and to establish guidelines for magnification correction. Methods We evaluated and compared spherical and linear markers of different sizes with focus on practicability, accuracy and precision. Markers were placed on foam pads or attached to flexible arms. Results Vertical marker deviation of 1 cm from the anatomical reference point corresponded to ∼1% of magnification error in our setting. Marker placement along the horizontal plane showed no significant magnification in the periphery of the radiograph. All markers showed good accuracy and the commercial spherical marker with a flexible segment arm had the best results regarding practicability. Discussion Our study suggests that marker type is not solely responsible for usability and accuracy but also the type of fixation. In the absence of a calibration marker, calculation of the magnification factor using a measurement tape during radiography is equally reliable. Use of a fixed averaged calculated calibration factor showed poor agreement compared with the marker calibration, probably due to variability in size of the animals. In conclusion, if precision matters, use of a calibration marker, which could be purchased or self-made, is advised.

scholarly journals Convolutional Neural Networks and Geometric Moments to Identify the Bilateral Symmetric Midplane in Facial Skeletons from CT Scans

Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 182
Author(s):  
Rodrigo Dalvit Carvalho da Silva ◽  
Thomas Richard Jenkyn ◽  
Victor Alexander Carranza
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Surgical Planning ◽  
Good Accuracy ◽  
Bilateral Symmetry ◽  
Ct Scans ◽  
Facial Skeleton ◽  
Intact Side ◽  
Geometric Moments ◽  
The Face

In reconstructive craniofacial surgery, the bilateral symmetry of the midplane of the facial skeleton plays an important role in surgical planning. Surgeons can take advantage of the intact side of the face as a template for the malformed side by accurately locating the midplane to assist in the preparation of the surgical procedure. However, despite its importance, the location of the midline is still a subjective procedure. The aim of this study was to present a 3D technique using a convolutional neural network and geometric moments to automatically calculate the craniofacial midline symmetry of the facial skeleton from CT scans. To perform this task, a total of 195 skull images were assessed to validate the proposed technique. In the symmetry planes, the technique was found to be reliable and provided good accuracy. However, further investigations to improve the results of asymmetric images may be carried out.

VALIDATED RP-HPLC AND UV-SPECTROSCOPY METHODS FOR THE ESTIMATION OF DAPAGLIFLOZIN IN BULK AND IN TABLETS

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (03) ◽  
pp. 44-51
Author(s):  
B. Sabbagh ◽  
B. V. S. Lokesh ◽  
G. A. Akouwah ◽  
Keyword(s):  
Good Accuracy ◽  
Uv Spectroscopy ◽  
Linear Regression Analysis ◽  
Molar Absorptivity ◽  
Hplc Method ◽  
Rp Hplc ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Uv Visible

Two methods were developed for the determination of dapagliflozin (DAPA) in pure form and in tablets. The procedure utilized was UV-Visible Spectroscopy and RP-HPLC with PDA detector to quantify DAPA in bulk and tablets. The sensitive linear range was identified for both methods within 0.5-5.0μg/mL. The linear regression analysis was identified for both methods with correlation coefficient(r)>0.99. The LOD and LOQ values were found to be 0.05 μg/mL and 0.5 μg/mL for the method by UV-Spectroscopy. The molar absorptivity (ε) was calculated as 1.27 X 105 L.mol-1cm-1. The RP-HPLC method produced LOD and LOQ values of 1.0 ng/mL and 0.5 μg/mL. Both methods were simple, precise, reproducible to quantify the amount of unknown in bulk as well as in tablets and estimated accurately within the range of 100.0±0.5%. Statistical analysis was performed on the data obtained. There was no significant difference between the developed and reported methods with p>0.05. Both methods can be applied for routine analysis of DAPA in bulk and tablets with good accuracy and precision.

Integrity and Fidelity Evaluation of Digital Evidence in Live Forensics

2014 ◽  
Vol 571-572 ◽  
pp. 90-99
Author(s):  
Lian Hai Wang ◽  
Qiu Liang Xu
Keyword(s):  
Experimental Error ◽  
Good Accuracy ◽  
Digital Evidence ◽  
System Error ◽  
Accuracy And Precision ◽  
Novel Method ◽  
Memory Acquisition ◽  
Measure Error ◽  
Live Forensics

The integrity and fidelity of digital evidence are very important in live forensics. Previous research has studied the uncertainty of live forensics based on different memory snapshots. However, this kind of method is not effective in practice. In fact, memory images are usually acquired by using forensics tools instead of using snapshots. Therefore, the integrity and fidelity of live evidence should be evaluated during the acquisition process. In this paper, we give a new viewpoint that memory acquisition can be regarded as a measurement of memory data. From this viewpoint, we evaluate the integrity and fidelity of live evidence in the process of physical memory acquisition. Firstly, several definitions about memory acquisition measure error are introduced to describe the trusty. Then, we analyze the experimental error and propose some suggestions on how to reduce it. A novel method is also developed to calculate the system error in detail. The results of a case study on Windows 7 and VMware virtual machine show that the experimental error has good accuracy and precision, which demonstrate the efficacy of the proposed reducing methods. The system error is also evaluated, that is, it accounts for the whole error from 30% to 50%. Last, a method is proposed to calculate changes or error of system process.

Hyperbolic Source Location of Crack Related Acoustic Emission in Bone

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
John O'Toole ◽  
Leo Creedon ◽  
John Hession ◽  
Gordon Muir
Keyword(s):  
Acoustic Emission ◽  
Constant Velocity ◽  
Good Accuracy ◽  
Source Location ◽  
Bovine Bone ◽  
Accuracy And Precision ◽  
Median Error ◽  
Acoustic Emission Source ◽  
Three Point Bend Test ◽  
Point Bend

Little work has been done on the localization of microcracks in bone using acoustic emission. Microcrack localization is useful to study the fracture process in bone and to prevent fractures in patients. Locating microcracks that occur before fracture allows one to predict where fracture will occur if continued stress is applied to the bone. Two source location algorithms were developed to locate microcracks on rectangular bovine bone samples. The first algorithm uses a constant velocity approach which has some difficulty dealing with the anisotropic nature of bone. However, the second algorithm uses an iterative technique to estimate the correct velocity for the acoustic emission source location being located. In tests with simulated microcracks, the constant velocity algorithm achieves a median error of 1.78 mm (IQR 1.51 mm) and the variable velocity algorithm improves this to a median error of 0.70 mm (IQR 0.79 mm). An experiment in which the bone samples were loaded in a three point bend test until they fractured showed a good correlation between the computed location of detected microcracks and where the final fracture occurred. Microcracks can be located on bovine bone samples using acoustic emission with good accuracy and precision.

scholarly journals Uv Spectrophotometric Methods for Determination of Sofosbuvir in Pure Form and Pharmaceutical Dosage Forms in Presence of Its Alkaline Degradate

2020 ◽  
pp. 12-25
Author(s):  
Zeinab Adel Nasr ◽  
Noha S. Said ◽  
Sawsan A. Abdel-Razeq
Keyword(s):  
Good Accuracy ◽  
Dosage Forms ◽  
Difference Spectra ◽  
Pharmaceutical Dosage Forms ◽  
Spectrophotometric Methods ◽  
Good Linearity ◽  
Ratio Difference ◽  
Accuracy And Precision ◽  
Tablet Dosage

Aims: Two spectrophotometric methods were developed and validated for the determination of sofosbuvir in presence of its alkaline degradate. Study Design: Ratio difference and ratio derivative methods were assisted for determination of sofosbuvir in presence of its alkaline degradate, laboratory-prepared mixtures and in tablet dosage forms. Place and Duration of Study: Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy (Girls), Al - Azhar University, between December 2019 and January 2020. Methodology: Two analytical methods were achieved and validated for the quantitative determination of Sofosbuvir in presence of its alkaline degradate. The first method was ratio difference (RD) method, where the UV absorption spectra of different concentrations of sofosbuvir were divided by the spectrum of a certain concentration (15 µg mL-1) as a devisor of its alkaline degradate to get the ratio difference spectra. Afterwards, the peak amplitudes difference between 253.7 and 243.5 nm were measured. The second method was the ratio derivative (1DR) method, where the first derivative of the ratio spectra (1DR) was obtained and its amplitude was measured at 247 and 268 nm. Good linearity was obtained over the concentration range of 3-15 µg mL-1 for the proposed methods. The proposed procedures were adopted for the selective determination of intact Sofosbuvir in presence of up to 80% of its degradation product. Sofosbuvir was exposed to different conditions as alkaline, acidic and oxidative degradation. Results: The proposed methods were developed and validated with good linearity range of 3-15 µg mL-1 for both methods, and also with good accuracy and precision. And the obtained results were statistically compared to those obtained by the reported method. Conclusion: Sofosbuvir was successfully determined by the proposed ratio difference and ratio derivative methods in bulk powder, laboratory prepared mixtures and tablet dosage form with good accuracy and precision. The methods were validated according to ICH guidelines. The results obtained were compared with those of the reported method and were found to be in good agreement.

Optimization of selective pressurized liquid extraction and ultrasonication-assisted QuEChERS methods for the determination of polybrominated diphenyl ethers in sediments

2015 ◽  
Vol 7 (22) ◽  
pp. 9542-9548 ◽  
Author(s):  
Shanjun Song ◽  
Xinhua Dai ◽  
Weihua Wang ◽  
Yajuan He ◽  
Zhao Liu ◽  
...  
Keyword(s):  
Polybrominated Diphenyl Ethers ◽  
Good Accuracy ◽  
Liquid Extraction ◽  
Pressurized Liquid Extraction ◽  
Real Samples ◽  
Accuracy And Precision ◽  
Diphenyl Ethers ◽  
Selective Pressurized Liquid Extraction

SPLE and ultrasonication-assisted QuEChERS were optimized for the analysis of PBDEs in sediments. Both methods were validated by SRMs with good accuracy and precision. Real samples were also analyzed and the results showed both methods practicable for PBDEs determination.

The Arcsecond Morphology of Compact Radio Sources

1982 ◽  
Vol 97 ◽  
pp. 175-176
Author(s):  
R. A. Perley
Keyword(s):  
Preliminary Analysis ◽  
Angular Size ◽  
Radio Sources ◽  
Use Of Self ◽  
Extended Structure ◽  
Self Calibration ◽  
Calibration Program ◽  
Calibration Techniques

As part of the VLA calibration program, 404 small angular size sources have been observed in the “A” array at both 6 and 20 cm with resulting resolutions of 0.4′ and 1.2′ respectively. Use of self-calibration techniques has allowed a search for associated extended structure to a level of ∼0.3% of the peak. Here we report preliminary analysis of the results.

Combined Determination of Phosphorus and Arsenic in Molybdenum Concentrate by Molybdenum Blue Spectrophotometric Method

2014 ◽  
Vol 1033-1034 ◽  
pp. 521-525
Author(s):  
Cheng Ying Zhou ◽  
Wei Qu ◽  
Liu Lu Cai
Keyword(s):  
Standard Deviation ◽  
Good Accuracy ◽  
Standard Addition ◽  
Additive Property ◽  
Molybdenum Blue ◽  
Accuracy And Precision ◽  
Relative Standard ◽  
Molybdenum Concentrate ◽  
Total Absorbance

This paper determined the total absorbance of phosphorus molybdenum blue and arsenic molybdenum blue by using the additive property of their absorbance values. By eliminating the interference of arsenic by reduction masking with composite reducing agent Na2SO3-Na2S2O3-KBr, the absorbance of phosphorus could be obtained. Thus, the content of phosphorus and arsenic could be calculated, respectively. The results show that the work curves of this method for phosphorus and arsenic are consistent with Beer’s law when the content of phosphorus and arsenic is 0-0.60ug/mL and 0-2.00ug/mL, respectively. The standard addition recovery rate of phosphorus and arsenic is 98.80%-101.04% and 99.00%-101.50%, respectively. The relative standard deviation of phosphorus and arsenic is less than 4.0% with good accuracy and precision. This method is simple and fast to determine phosphorus and arsenic in molybdenum concentrate, and the results are accurate and reliable.

scholarly journals Validated Stability – Indicating Methods for Determination of Sofosbuvir by UPLC and HPTLC in Pure Form and Tablet Dosage Forms

2019 ◽  
pp. 1-13
Author(s):  
Sawsan A. Abdel-Razeq ◽  
Zeinab Adel Nasr ◽  
Noha S. Said
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
High Performance ◽  
Good Accuracy ◽  
Degradation Products ◽  
Dosage Forms ◽  
Stability Indicating ◽  
Accuracy And Precision ◽  
Tablet Dosage

Aims: Two simple and sensitive stability- indicating methods were developed and validated for the quantitative determination of sofosbuvir in presence of its degradation products. Study Design: Ultra high performance liquid chromatography (UPLC), High performance thin layer chromatography (HPTLC) are developed for determination of sofosbuvir in presence of its degradation products, laboratory-prepared mixtures and in tablet dosage forms. Place and Duration of Study: Analytical Chemistry Department, Faculty of Pharmacy (Girls), Al-Azhar University, between August 2018 and March 2019. Methodology: Two simple and sensitive stability- indicating methods were developed and validated for the quantitative determination of Sofosbuvir in presence of its degradation products. The first method was an Ultra Performance Liquid Chromatography (UPLC) method, in which efficient separation was carried out on phenomenex kinetex 2.6 μm C18 100 A column using a mobile phase consisting of filtered and degassed mixture of 0.1% ortho-phosphoric acid in water and methanol with the ratio of (40:60% v/v) adjusted to pH 3.5, at a flow rate of 1 mL min-1 and UV detection at 260 nm at ambient temperature. The second method is a high performance- thin layer chromatographic one (HPTLC) in which chromatographic separation was performed on silica gel 60 F254 plates, with methanol – chloroform – ammonia (2.5: 6: 1.5 % v/v/v) as a developing system followed by densitometric determination at 261 nm. Sofosbuvir was subjected to stress conditions including alkaline, acidic and oxidative degradation. Results: Beer’s law was obeyed over the range of 1-20 μg mL–1 for UPLC and 2-12 μg / spot for HPTC with good accuracy and precision using the two procedures, respectively. Results obtained was statistically analysed and found to be in accordance with those given by the reported method. Conclusion: The proposed methods were successfully applied for the determination of sofosbuvir in bulk powder, laboratory prepared mixtures and pharmaceutical dosage form with good accuracy and precision. The methods were validated according to ICH guidelines. The results obtained were compared with those of the reported method and were found to be in good agreement.

scholarly journals Fourth Derivative and Compensated Area under the Curve Spectrophotometric Methods Used for Analysis Meloxicam in the Local Market Tablet

2019 ◽  
Vol 29 (3) ◽  
pp. 70
Author(s):  
Ruba Fahmi Abbas ◽  
Neda Ibrahim Mahdi ◽  
Ali Amer Waheb Amer Waheb ◽  
Amjad Gali Aliwi Gali Aliwi ◽  
Marwa S. Falih
Keyword(s):  
Good Accuracy ◽  
Area Under The Curve ◽  
Local Market ◽  
Linear Calibration ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision ◽  
Fourth Derivative ◽  
Two Peaks ◽  
Tablet Dosage ◽  
Good Agreement

Two Rapid, direct, ecological friendly and economical spectrophotometric methods were used for estimation of meloxicam in the market Tablet dosage form. The First method is based on the use the fourth order derivative spectrum (D4) and the second method is depend-ed on the ratio of the area under the curve for the two peaks in the drug (Compensated area under the curve). The linear calibration graphs of the two methods were measured in the con-centration range (5-35)mg/l and the average of recoveries for local market Tablet (AWA)® were 99.8% for D4 method and 100.2% for CAUC method which indicating a good accuracy and precision for these methods. In this study, the results obtained by these suggested meth-ods have been successfully statistically compared by t-test and Mann-Whitney test showed a good agreement.

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