scholarly journals Characterization of cone size and centre in keratoconic corneas

2020 ◽  
Vol 17 (169) ◽  
pp. 20200271
Author(s):  
Ashkan Eliasy ◽  
Ahmed Abass ◽  
Bernardo T. Lopes ◽  
Riccardo Vinciguerra ◽  
Haixia Zhang ◽  
...  
Keyword(s):  
Mirror Symmetry ◽  
Significant Negative Correlation ◽  
Maximum Height ◽  
Corneal Tissue ◽  
The Novel ◽  
Spherical Coordinate ◽  
Second Derivatives ◽  
Novel Method ◽  
The Mean

A novel method to locate the centre of keratoconus (KC) and the transition zone between the pathological area and the rest of the corneal tissue is proposed in this study. A spherical coordinate system was used to generate a spherical height map measured relative to the centre of the optimal sphere fit, and normal to the surface. The cone centre was defined as the point with the maximum height. Second derivatives of spherical height were then used to estimate the area of pathology in an iterative process. There was mirror symmetry between cone centre locations in both eyes. The mean distance between cone centre and corneal apex was 1.45 ± 0.25 mm (0.07–2.00), the mean cone height normal to the surface was 37 ± 23 µm (2–129) and 75 ± 45 µm (5–243) in the anterior and posterior surfaces, respectively. There was a significant negative correlation between the cone height and the radius of the sphere of optimal fit ( p < 0.05 for both anterior and posterior surfaces). On average, posterior cone height was larger than the corresponding anterior cone height by 37 ± 24 µm (0–158). The novel method proposed can be used to estimate the cone centre and area, and explore the changes in anterior and posterior corneal surfaces that take place with KC progression. It can help improve understanding of keratoconic corneal morphology and assist in developing customized treatments.

Extracting the Elastic Modulus of Compliant Materials Using a Novel Plate Bulge Testing Technique

2008 ◽  
Author(s):  
S. Golan ◽  
D. Elata ◽  
U. Dinnar
Keyword(s):  
Elastic Modulus ◽  
Plate Theory ◽  
Biological Tissues ◽  
Bulge Test ◽  
The Novel ◽  
Membrane Mechanics ◽  
Testing Technique ◽  
Bulge Testing ◽  
Novel Method

The mechanical properties of compliant materials such as biological tissues and biocompatible soft polymers are essential in medical research and engineering applications. These properties are often determined using techniques that require costly instrumentation (e.g. pull test machines). Alternative and more accessible methods can significantly aid the characterization process. The bulge test determines a material elastic modulus by analyzing the pressure-deflection response of thin samples made of this material. The technique has been extensively employed in the characterization of metals and semiconductors (modulus ∼ 100 GPa). By employing plate rather than membrane mechanics, the present study extends bulge testing to characterize materials with a modulus that is five orders of magnitude lower (∼ 1 MPa). The novel method is demonstrated analytically using plate theory, numerically using finite element modeling and experimentally by successfully applying it to polydimethylsiloxane (modulus ∼ 1.33 MPa). The introduced technique does not require costly equipment, is simple to implement and presents an appealing alternative to current characterization approaches.

A Novel Method to Compensate Fiber Nonlinearities by Using NAFO Model

2018 ◽  
Vol 39 (4) ◽  
pp. 387-392
Author(s):  
Kuldeep Singh ◽  
Sandeep K. Arya
Keyword(s):  
Wiener Filter ◽  
The Novel ◽  
Third Order ◽  
Fiber Nonlinearities ◽  
Iir Filter ◽  
Bee Colony ◽  
Efficient Performance ◽  
Novel Method ◽  
Fiber Link ◽  
The Mean

Abstract This paper proposes the Nonlinear Adaptive Filter bank–based artificial bee colony Optimizer (NAFO) based on Wiener filter for inverse modeling of nonlinear fiber link. Here a third-order inverse Volterra-based nonlinear equalizer (VNLE) is used to compensate the fiber nonlinearities using MATLAB Simulink. In the novel method the Mean Square Error (MSE) of the optical link is measured and compared with IIR-filter based technique. The MSE is reported to be 10–14 value lesser in the novel experimental setup consequently the proposed technique shows enhanced and efficient performance.

In Situ Synthesis and Characterization of Multi-walled Carbon Nanotube/Prussian Blue Nanocomposite Materials and Application

2008 ◽  
Vol 8 (9) ◽  
pp. 4453-4460
Author(s):  
Jian-Ding Qiu ◽  
Meng Xiong ◽  
Ru-Ping Liang ◽  
Jia Zhang ◽  
Xing-Hua Xia
Keyword(s):  
Carbon Nanotube ◽  
Prussian Blue ◽  
Relative Concentration ◽  
Surface Oxidation ◽  
Heating Process ◽  
The Novel ◽  
Multi Walled Carbon Nanotube ◽  
Novel Method

An effective and facile in situ electroless deposition approach for the fabrication of multi-walled carbon nanotube-supported Prussian blue nanoparticle (MWNTs/PB NP) composite nanomaterials is demonstrated in this article. The coverage of PB NPs on MWNTs is tunable by varying the experimental parameters, such as the initial molar concentration of FeCl3 + K3[Fe(CN)6], the relative concentration of FeCl3 + K3[Fe(CN)6] to MWNTs, and the temperature and duration of the heat treatment. This method involves a simple mixing process followed by a mild heating process and does not need the exhaustive surface oxidation process of MWNTs. TEM, FTIR, UV, and XRD are all used to characterize the MWNTs/PB composite materials. In addition, the electrochemical behavior of PB and catalysis of the reduction of H2O2 are investigated. The novel method is expected to be applicable for preparation of other coordination polymer/MWNTs composites and finds use in applications for electronic nanodevices.

Observations on the early renal uptake and later tubular metabolism of radiolabelled aprotinin (Trasylol) in man: theoretical and practical considerations

1993 ◽  
Vol 84 (2) ◽  
pp. 231-235 ◽  
Author(s):  
R. Rustom ◽  
J. S. Grime ◽  
P. Maltby ◽  
H. R. Stockdale ◽  
M. Critchley ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
The Novel ◽  
Renal Disease Progression ◽  
Renal Handling ◽  
Renal Uptake ◽  
Intravenous Injections ◽  
Constant Rate ◽  
Novel Method ◽  
The Mean ◽  
Renal Tubular

1. The novel method recently developed to measure renal tubular degradation of filtered proteins in man using radiolabelled aprotinin (Trasylol) has been modified to allow the fate and the significance of the renal catabolism of radiolabelled aprotinin to be determined beyond 24 h. 2. Ten renal patients with normal kidney function and variable proteinuria each received two separate intravenous injections of radiolabelled aprotinin, 5.0 mg of 99mTc-labelled aprotinin (40 MBq) and 0.5 mg of 131I-labelled aprotinin (5 MBq). Chromatography (Sephadex-G-25-M) was used to separate undegraded radiolabelled aprotinin from the free isotope in urine and plasma. Renal uptake from σ-camera images (24 h for 99mTc-Iabelled aprotinin and up to 96 h for 131I-labelled aprotinin) and urinary activity (48 and 96 h, respectively) were measured. 3. The renal handling of radiolabelled aprotinin was similar with the two isotopes. Chromatography showed that all plasma activity was undegraded radiolabelled aprotinin, and urine activity was only the free isotopic label. 4. Kidney uptake of 131I-labelled aprotinin was prompt, reaching a cumulative maximum of 37.1 ± 3.0% of dose at 24 h, but falling exponentially thereafter to 5.6 ± 1.0% of dose at 96 h. 5. The rate of excretion of the free label in urine, i.e. the metabolic rate of radiolabelled aprotinin, was relatively constant over the first 24 h (1.6 ± 0.09% of dose/h), but then fell in parallel with the diminishing activity over the kidney, i.e. to 1.0 ± 0.1% of dose/h over 24–48 h and to only 0.4 ± 0.08% of dose/h over 72–96 h. 6. Fractional renal degradation of radiolabelled aprotinin, derived from the mean rate of urinary excretion of the free isotope over a given interval divided by the mean cumulative kidney uptake over the same interval (h−1), fell steeply early and then more slowly to 0.05 ± 0.003 h−1 at 14.25h, and stabilized thereafter varying little between 0.04 ± 0.01 h−1 and 0.05 ± 0.01 h−1 over 36–84 h. 7. Thus, the maximum cumulative kidney uptake of radiolabelled aprotinin is achieved by 24 h, when the metabolic rate and fractional degradation are reliable indices of catabolism. The falling metabolic rate after 24 h, together with the constant rate of fractional degradation, suggests that there is a readily saturable step in the metabolic process. Hence, duplicate measurements of radiolabelled aprotinin uptake and metabolism around 24 h only (12–36 h) are sufficient and offer a simple and a reliable tool in clinical studies for determining the link between renal tubular protein degradation and renal disease progression.

Quantification of Left Ventricular Mass Using Two-Dimensional Transthoracic Echocardiography - A Novel Method with High Accuracy and Reproducibility

2021 ◽  
Author(s):  
Charlotte Burup Kristensen ◽  
Katrine Aagaard Myhr ◽  
Frederik Fasth Grund ◽  
Niels Vejlstrup ◽  
Christian Hassager ◽  
...  
Keyword(s):  
Left Ventricular Mass ◽  
Wall Thickness ◽  
Left Ventricular ◽  
The Other ◽  
The Novel ◽  
Two Dimensional ◽  
Novel Method ◽  
Cardiac Disorders ◽  
The Mean ◽  
Better Than

Abstract Purpose Increased left ventricular mass (LVM) is a strong independent predictor for adverse cardiovascular events, but conventional echocardiographic methods used to assess and monitor individuals are limited by poor reproducibility and accuracy. We aimed to develop an echocardiographic method for LVM-quantification that is simple, reproducible and accurate. Methods The novel method adds the mean wall thickness to the left ventricular end-diastolic volume acquired using the biplane model of discs. The mean wall thickness is acquired from the parasternal short axis view. Cardiac assessment was performed using echocardiography followed immediately by cardiac magnetic resonance in 85 subjects with different left ventricular geometries, ranging from patients with various cardiac disorders (n=41) to individuals without known cardiac disorders (n=44). We compared the novel two-dimensional (2D) method to various conventional one-dimensional (1D) and 2D methods as well as three-dimensional (3D) echocardiography. Results The novel method had better reproducibility in intra-examiner (coefficients of variation (CV) 9% vs. 11-14%) and inter-examiner analysis (CV 9% vs. 10-20%) than the other methods. Accuracy of the novel method was similar to 3D (mean difference±95% limits of agreement, CV): Novel: 2±50g,15% vs. 3D: 2±51g, 16%; and better than the 1D-method by Devereux (7±76g, 23%). Conclusion The novel 2D-based method for LVM-quantification had better reproducibility than the other echocardiographic methods. Accuracy was similar to 3D and better than conventional methods. As endocardial tracings using the biplane model forms part of the standard echocardiographic protocol, the novel method can easily be integrated into any echocardiographic software, without substantially increasing analysis time.

scholarly journals INCLUSION RATIO BASED ESTIMATOR FOR THE MEAN LENGTH OF THE BOOLEAN LINE SEGMENT MODEL WITH AN APPLICATION TO NANOCRYSTALLINE CELLULOSE

2014 ◽  
Vol 33 (2) ◽  
pp. 147
Author(s):  
Mikko Niilo-Rämä ◽  
Salme Kärkkäinen ◽  
Dario Gasbarra ◽  
Timo Lappalainen
Keyword(s):  
Censored Data ◽  
Real World ◽  
Line Segment ◽  
Current Work ◽  
The Novel ◽  
Simulation Experiments ◽  
Industrial Data ◽  
Segment Model ◽  
Novel Method ◽  
The Mean

A novel estimator for estimating the mean length of fibres is proposed for censored data observed in square shaped windows. Instead of observing the fibre lengths, we observe the ratio between the intensity estimates of minus-sampling and plus-sampling. It is well-known that both intensity estimators are biased. In the current work, we derive the ratio of these biases as a function of the mean length assuming a Boolean line segment model with exponentially distributed lengths and uniformly distributed directions. Having the observed ratio of the intensity estimators, the inverse of the derived function is suggested as a new estimator for the mean length. For this estimator, an approximation of its variance is derived. The accuracies of the approximations are evaluated by means of simulation experiments. The novel method is compared to other methods and applied to real-world industrial data from nanocellulose crystalline.

scholarly journals A Novel Procedure of Prepuce Reconstruction Customized to the Religious Needs of Some Individuals

2021 ◽  
Vol 54 (02) ◽  
pp. 114-117
Author(s):  
Richie Gupta ◽  
Sandeep Mehta ◽  
Rajat Gupta
Keyword(s):  
Urinary Infection ◽  
Glans Penis ◽  
The Novel ◽  
Meatal Stenosis ◽  
Penile Erections ◽  
Novel Method ◽  
The Mean

Abstract Background Authors describe a novel procedure in a group of patients for prepuce reconstruction, ensuring complete glans penis coverage who had either been circumcised in childhood or had congenitally short prepuce. Methods Case records of all cases done by the novel method which involved penile degloving and maintenance of neoprepuce, with the help of de-epithelization of glans penis and a few key sutures performed over the period from January 2010 to December 2019 were reviewed retrospectively. A total of 46 patients, 32 had congenitally short prepuce and 14 had previous circumcision. Results All the patients had complete glans penis coverage. None of the patients had complications like urinary infection, meatal stenosis, collection in neoprepucial sac, balanitis, or posthitis. The mean followup was 23.24 months in 37 patients. Nine lost to followup. Conclusions The procedure is simple, gives reliable results, and is customized to the needs of the patients. It does not interfere with penile erections.

Reaktion von Oxomolybdän-Komplexen mit Alkyldithiocarbazaten. Darstellung und Charakterisierung von Hydrazido- und Diazenido-Komplexen des Molybdäns / Reaction of Oxomolybdenum Complexes with Alkyldithiocarbazates. Synthesis and Characterization of Hydrazido- and Diazenido Complexes of Molybdenum

1987 ◽  
Vol 42 (5) ◽  
pp. 589-598 ◽  
Author(s):  
Rainer Mattes ◽  
Heinz Scholand ◽  
Ulrich Mikloweit ◽  
Volker Schrenk
Keyword(s):  
Tridentate Ligand ◽  
The Novel ◽  
Unique Combination ◽  
Dimeric Complex ◽  
X Ray ◽  
X Ray Crystallography ◽  
Metal Atoms ◽  
The Mean ◽  
Trigonal Prismatic

(2).The reaction of alkyldithiocarbazates NH2NHC(S)SR′ with MoO2(S2CNR2)2 R, R′ = Me, Et) yields the diazenido hydrazido complexes Mo(NNC(S)SR′)(NH2NC(S)SR′)(S2CNR2)2 (1), reaction with the molybdenum hydroxylamidate complex MoO2(ONMe2)2 gives the diazenidobis( hydrazido) complex Mo(NNC(S)SMe)(NH2NC(S)SMe)2(Me2NO)-CH3OH The crystal structures of 1 a (R = Me, R′ = Et) and 2 have been determined. The metal atoms in 1 a and 2 are seven coordinated and have MoN2S5 and MoN3O2S2 ligand arrays, respectively. Both compounds contain the approximately linear diazenido ligand NNC(S)SR in addition to one (1a) or two (2) N,S-chelating hydrazido(1-) ligands NH2NC(S)SR. When 1a is treated with HCl, the dimeric complex (Me2NCS2)(O)Mo(μ-NNC(S)SEt)2 Mo(S2CNMe2) (4) is obtained. X-ray crystallography showed 4 to be an asymmetric dinuclear complex, with a Mo-Mo distance of 267.2(1) pm. One Mo site has a square pyramidal MoOS2N2 geometry, while the other one has an approximately trigonal prismatic MoN2S4 geometry. The mean N-N distance in 4 is 135(1) pm. The reaction of NH2NHC(S)SMe with MoO2(acac)2 yields Mo(Me2CNNC(S)SMe)(NNC(S)SMe)(MeSC(S)NNC(S)SMe) (3). Its structure has been determined by X-ray crystallography. 3 contains a unique combination of three different N- and S-chelating ligands: the Schiff base Me2C=NNC(S)SMe, the highly bent bidentate diazenido ligand NNC(S)SMe (∡ Mo-N-N = 142.1(5)°), and the novel planar tridentate ligand MeSC(S)NNC(S)SMe. The latter can be taken as neutral diacyldiazene or, more likely, as the dianion of the as yet unknown MeSC(S)NH -NHC(S)SMe. The N - N distance in this ligand is 136.1(9) pm.

Characterization of the novel aspartic proteinases, BACE and BACE2

2000 ◽  
Vol 38 ◽  
pp. S124
Author(s):  
S Kametaka
Keyword(s):  
The Novel ◽  
Aspartic Proteinases

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

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