Fidelity of the Estimation of the Deformation Gradient From Data Deduced From the Motion of Markers Placed on a Body That is Subject to an Inhomogeneous Deformation Field

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Vít Průša ◽  
K. R. Rajagopal ◽  
U. Saravanan
Keyword(s):  
Finite Number ◽  
Data Reduction ◽  
Deformation Gradient ◽  
Quantitative Description ◽  
The Body ◽  
Inhomogeneous Deformation ◽  
Actual Error ◽  
The Difference

Practically all experimental measurements related to the response of nonlinear bodies that are made within a purely mechanical context are concerned with inhomogeneous deformations, though, in many experiments, much effort is taken to engender homogeneous deformation fields. However, in experiments that are carried out in vivo, one cannot control the nature of the deformation. The quantity of interest is the deformation gradient and/or its invariants. The deformation gradient is estimated by tracking positions of a finite number of markers placed in the body. Any experimental data-reduction procedure based on tracking a finite number of markers will, for a general inhomogeneous deformation, introduce an error in the determination of the deformation gradient, even in the idealized case, when the positions of the markers are measured with no error. In our study, we are interested in a quantitative description of the difference between the true gradient and its estimate obtained by tracking the markers, that is, in the quantitative description of the induced error due to the data reduction. We derive a rigorous upper bound on the error, and we discuss what factors influence the error bound and the actual error itself. Finally, we illustrate the results by studying a practically interesting model problem. We show that different choices of the tracked markers can lead to substantially different estimates of the deformation gradient and its invariants. It is alarming that even qualitative features of the material under consideration, such as the incompressibility of the body, can be evaluated differently with different choices of the tracked markers. We also demonstrate that the derived error estimate can be used as a tool for choosing the appropriate marker set that leads to the deformation gradient estimate with the least guaranteed error.

Determination of the pH of Hemolyzed Packed Red Cells from Arterial Blood

1961 ◽  
Vol 7 (5) ◽  
pp. 536-541 ◽  
Author(s):  
May K Purcell ◽  
Gertrude M Still ◽  
Theodore Rodman ◽  
Henry P Close
Keyword(s):  
Blood Cell ◽  
Normal Subjects ◽  
The Body ◽  
Red Cell ◽  
Arterial Blood ◽  
Fiducial Probability ◽  
The Mean ◽  
Red Cell Ph

Abstract A technic is described for the determination of the in vivo pH of red blood cell hemolysates. The mean arterial red cell pH of 20 normal subjects was 7.19 with a range of 7.15 to 7.22. The fiducial probability at the 0.95 level is 7.13 to 7.25. The mean difference in pH between plasma and cells was 0.21, with a range of 0.15 to 0.23. It is suggested that changes in pH of erythrocytes may reflect changes in other less accessible cells of the body and that the determination may be a useful research and clinical procedure in the study of metabolic and respiratory derangements.

XXI. Description of a hydropneumatic baroscope

1839 ◽  
Vol 129 ◽  
pp. 425-431
Keyword(s):  
Thin Sheet ◽  
Simple Calculation ◽  
The Body ◽  
The Other ◽  
Floating Body ◽  
Convex Side ◽  
The Difference ◽  
Increased Pressure ◽  
Brass Wire

The principle on which the instrument I am about to describe is constructed, is, that the volume of a given quantity of air under a constant temperature, is inversely as the pressure to which it is subjected ; and the means I employ to estimate the change of volume which that quantity of air undergoes, by being subjected to differences of pressure caused by a change of elevation, are the determination of the difference of weight which a floating body is capable of sustaining in both situations. Thus, if a vessel containing a quantity of air and water be floated in water, and there be a com­munication between the water in the floating body and that in which it floats, it will follow, that when such an apparatus is subjected to diminished pressure, the air within the float will dilate, and cause a volume of water equal in amount to the dilatation of the air to be driven from the float; and the difference of weight which the floating body will sustain, will be the exact weight of the water expelled : if such an appa­ratus is subjected to an increased pressure, the air within it will contract, and consequently a quantity of water, from that in which it floats, will enter the float, and the diminished weight it is capable of sustaining will be the weight of the water which has entered the float, in consequence of the diminution of the volume of the air. It is by such means, with the instrument immediately to be described, and by the help of a very simple calculation, that I propose to determine the difference of level between any two places. Plate X. fig. 1. represents the floating part, made of thin sheet brass, the body of which ( a ), in form the frustum of a cone, is nine inches long, two inches in dia­meter at one end, and one inch at the other, and capable of containing about fourteen cubic inches. In the centre of the widest end, a small stud of brass ( b ) is hard sol­dered, into which a brass wire ( c ) is screwed, an inch and three-eighths long, and about one twenty-fifth or one thirtieth of an inch in diameter : the other end of the wire is screwed into a brass stud in the middle of the convex side of a shallow cup ( d ), made also of brass, and as light as possible, so that it will retain its shape, and be capable of sustaining a weight of about eight hundred or one thousand grains.

scholarly journals HEMATOSALIVAL BARRIER IN CLINICAL PRACTICE

2021 ◽  
Vol 17 (2) ◽  
pp. 62-67
Author(s):  
Oleg Chuykin ◽  
Maria Shtanko ◽  
Kristina Kuchuk
Keyword(s):  
Oral Fluid ◽  
Biological Fluids ◽  
The Body ◽  
Internal Environment ◽  
Pathological Conditions ◽  
Therapeutic Measures ◽  
The Difference ◽  
And Control ◽  
Level Analysis

To maintain homeostasis of the internal environment of the body, mechanisms are needed that control the exchange of various components between blood and the internal environment of tissues and organs. One of these physiological structures is the blood-salivary barrier, which regulates the selective metabolism between blood and oral fluid. Changes in the composition of biological fluids (blood and saliva) can be used as markers for diagnosing pathological conditions of the body and the dynamics of therapeutic measures. Of great importance is the study of the blood-salivary barrier for the search for drugs that are selectively transferred from the blood to the saliva. Some drugs are excreted in saliva at a concentration higher than they are in the blood. However, more often the concentration of drugs in saliva is much lower than in blood serum. Purpose: to form a list of the main trends and scientific and practical directions on the func-tioning of the hematosalvarial barrier. Materials and methods: to analyze the topic of the clinical significance of the hematosalvarial barrier, periodicals and scientific journals of domestic and foreign literature were studied, which determined the difference in the levels of trace elements, hormones, immune complexes between the oral fluid and serum. Conclusion: Analysis of literature data shows that the function of the blood-salivary barrier acts as a nonspecific adaptive mechanism, while saliva reflects the state of the protective functions of the barrier at the organismal level. Analysis of the selectivity and permeability of the blood-salivary barrier, as well as determination of changes in the composition and proper-ties of blood and oral fluid, can optimize and facilitate the diagnosis and control of treatment of various diseases of the oral cavity and the body as a whole.

Determination of the Accuracy of Segmented Representations of Cable Shape

1975 ◽  
Vol 97 (2) ◽  
pp. 472-478 ◽  
Author(s):  
H. T. Wang
Keyword(s):  
Finite Number ◽  
Static Case ◽  
Two Dimensional ◽  
Comprehensive Investigation ◽  
Finite Segment ◽  
The Difference ◽  
Number Of Segments

The results of a comprehensive investigation of the accuracy of representing a continuous cable by a finite number of segments are presented. The results are limited to the two-dimensional static case. The accuracy of three different finite-segment models is evaluated for a number of segments ranging from 1 to 40. The difference between the three models lies in the manner in which the inclination of each segment is obtained. The results basically show that relatively few segments are required to accurately obtain the overall geometry and resultant tension of the cable.

Space Orientation of Total Hip Prosthesis

1986 ◽  
Vol 27 (6) ◽  
pp. 619-627 ◽  
Author(s):  
K. Herrlin ◽  
G. Selvik ◽  
H. Pettersson
Keyword(s):  
Present Method ◽  
Hip Prosthesis ◽  
The Body ◽  
Neutral Position ◽  
Total Hip Prosthesis ◽  
Total Hip ◽  
Prosthetic Loosening

A method for in vivo determination of orientation and relation in space of components of total hip prosthesis is described. The method allows for determination of the orientation of the prosthetic components in well defined anatomic planes of the body. Furthermore the range of free motion from neutral position to the point of contact between the edge of the acetabular opening and the neck of the femoral component can be determined in various directions. To assess the accuracy of the calculations a phantom prosthesis was studied in nine different positions and the measurements of the space oriented parameters according to the present method correlated to measurements of the same parameters according to Selvik's stereophotogrammetric method. Good correlation was found. The role of prosthetic malpositioning and component interaction evaluated with the present method in the development of prosthetic loosening and displacement is discussed.

scholarly journals Determination of malondialdehyde and glutathione levels in the liver of mice orally administered with a mixture of the aqueous extracts of Ganoderma lucidum (Curtis) P. Karst, Mint (Mentha avensis L.) and stevia (Stevia rebaudiana Bertoni)

2018 ◽  
Vol 17 (05) ◽  
pp. 77-83
Author(s):  
Minh T. L. Tran
Keyword(s):  
Antioxidant Activity ◽  
Ganoderma Lucidum ◽  
Radical Scavenging ◽  
Stevia Rebaudiana ◽  
The Body ◽  
Stevia Rebaudiana Bertoni ◽  
High Antioxidant Activity ◽  
Important Drug

Oxidative stress has been studied by scientists because it is a factor increasing diseases, such as cancer, diabetes... through the production of harmful free radicals to the body. Ganoderma lucidum (Curtis) P. Karst is always considered an important drug in the prevention and treatment of diseases by the action of polysaccharide and triterpenoid. In addition, Stevia rebaudiana Bertoni has recently been shown to have antioxidant and anti-inflammatory properties. Mint (Mentha avensis L.) is a common medicinal herb. The mixture consisting of the aqueous extract of Ganoderma lucidum (Curtis) P. Karst, mint and stevia powder had a high antioxidant activity, in free radical scavenging method (DPPH), reaching 85.7% at concentration 1000 μg/mL and valuable IC50 was 559.7 μg/mL. For in vivo study on the model of cyclophosphamide-induced liver damage in white mice, the concentrations of malondialdehyde and glutathione in liver showed that the mixture had antioxidant activity in the direction of hepatoprotective effect

scholarly journals Deep sequence modelling for predicting COVID-19 mRNA vaccine degradation

2021 ◽  
Vol 7 ◽  
pp. e597
Author(s):  
Talal S. Qaid ◽  
Hussein Mazaar ◽  
Mohammed S. Alqahtani ◽  
Abeer A. Raweh ◽  
Wafaa Alakwaa
Keyword(s):  
Low Cost ◽  
Rapid Development ◽  
The Body ◽  
High Potency ◽  
Low Protein ◽  
Deep Model ◽  
The Difference ◽  
Encoding Method ◽  
In Vivo Delivery

The worldwide coronavirus (COVID-19) pandemic made dramatic and rapid progress in the year 2020 and requires urgent global effort to accelerate the development of a vaccine to stop the daily infections and deaths. Several types of vaccine have been designed to teach the immune system how to fight off certain kinds of pathogens. mRNA vaccines are the most important candidate vaccines because of their capacity for rapid development, high potency, safe administration and potential for low-cost manufacture. mRNA vaccine acts by training the body to recognize and response to the proteins produced by disease-causing organisms such as viruses or bacteria. This type of vaccine is the fastest candidate to treat COVID-19 but it currently facing several limitations. In particular, it is a challenge to design stable mRNA molecules because of the inefficient in vivo delivery of mRNA, its tendency for spontaneous degradation and low protein expression levels. This work designed and implemented a sequence deep model based on bidirectional GRU and LSTM models applied on the Stanford COVID-19 mRNA vaccine dataset to predict the mRNA sequences responsible for degradation by predicting five reactivity values for every position in the sequence. Four of these values determine the likelihood of degradation with/without magnesium at high pH (pH 10) and high temperature (50 degrees Celsius) and the fifth reactivity value is used to determine the likely secondary structure of the RNA sample. The model relies on two types of features, namely numerical and categorical features, where the categorical features are extracted from the mRNA sequences, structure and predicted loop. These features are represented and encoded by numbers, and then, the features are extracted using embedding layer learning. There are five numerical features depending on the likelihood for each pair of nucleotides in the RNA. The model gives promising results because it predicts the five reactivity values with a validation mean columnwise root mean square error (MCRMSE) of 0.125 using LSTM model with augmentation and the codon encoding method. Codon encoding outperforms Base encoding in MCRMSE validation error using the LSTM model meanwhile Base encoding outperforms codon encoding due to less over-fitting and the difference between the training and validation loss error is 0.008.

scholarly journals The Mutual Beneficial Effect between Medical Imaging and Nanomedicine

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Huiting Qiao ◽  
Libin Wang ◽  
Jintao Han ◽  
Yingmao Chen ◽  
Daifa Wang ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Medical Imaging ◽  
Beneficial Effect ◽  
Quantitative Description ◽  
The Body ◽  
The Other ◽  
Metabolic Study ◽  
Toxicological Research

The reports on medical imaging and nanomedicine are getting more and more prevalent. Many nanoparticles entering into the body act as contrast agents, or probes in medical imaging, which are parts of nanomedicines. The application extent and the quality of imaging have been improved by nanotechnique. On one hand, nanomedicines advance the sensitivity and specificity of molecular imaging. On the other hand, the biodistribution of nanomedicine can also be studiedin vivoby medical imaging, which is necessary in the toxicological research. The toxicity of nanomedicine is a concern which may slow down the application of nanomedical. The quantitative description of the kinetic process is significant. Based on metabolic study on radioactivity tracer, a scheme of pharmacokinetic research of nanomedicine is proposed. In this review, we will discuss the potential advantage of medical imaging in toxicology of nanomedicine, as well as the advancement of medical imaging prompted by nanomedicine.

The Distribution of Temperatures in a Hot/Cold Die Set: The Effect of the Pressure, Temperature, and Material

1995 ◽  
Vol 117 (2) ◽  
pp. 220-227 ◽  
Author(s):  
J. G. Lenard ◽  
M. E. Davies
Keyword(s):  
Initial Conditions ◽  
Control Program ◽  
The Body ◽  
Temperature Fields ◽  
Surface Temperatures ◽  
Direct Measurements ◽  
Die Set ◽  
The Difference ◽  
Interface Pressures

Modern hot metalforming operations require a predictive-adaptive control program in which the predictive component precalculates the necessary parameters—such as temperatures and loads—and the adaptive component sets up, monitors and adjusts the forming equipment. One of the needs of a predictive model of the process is for an understanding of the boundary conditions at the surface of contact. For high temperature operations, one of these conditions is described by the heat transfer coefficient, relating the heat flux and the difference of the temperatures of the contacting surfaces, at the die-workpiece interface. The surface temperatures are, of course, dependent on the distribution of the temperatures within the body of the dies. The determination of these distributions is the topic of the present project. Thermocouples embedded in a cold/hot die set as well as thermocouples placed on the surface of contact are used to monitor the temperature fields, within the body as well as on the surfaces, for various interface pressures, initial temperatures and materials. The results indicate that direct measurements of the temperatures of the contacting surfaces is very difficult and may lead to significant errors. It is recommended that a mathematical model, which uses the measured internal temperatures as initial conditions, should be employed to calculate the contact surface temperatures.

Problems of theStufenbaulehre: Kelsen’s Failure to Derive the Validity of a Norm from Another Norm

2007 ◽  
Vol 20 (1) ◽  
pp. 35-67 ◽  
Author(s):  
András Jakab
Keyword(s):  
Legal Order ◽  
The Body ◽  
Dead Body ◽  
Basic Norm ◽  
The Difference ◽  
Theory Of Law ◽  
Transplanted Organs ◽  
Logical Result ◽  
Law Making

TheStufenbaulehreis a central and founding element of the Pure Theory of Law (PTL).Most of the criticism ofStufenbaulehretargets the idea of the basic norm (Grundnorm), however unjustified. This criticism stems from a misunderstanding of the presumptive character of the basic norm and of the whole legal order. Others have criticised the relativisation of the difference between individual and general norms, Kelsen’s monism, and the determination of the validity of a norm by a single other norm. This can be refuted as well - either because their critique does not concern an essential part ofStufenbaulehre(monism), or becauseStufenbaulehrecan be saved by making a small modification to it. However, there is one lethal criticism. It concerns the founding thought of the wholeStufenbaulehre, i.e., the derivation of validity. In a law-making process, there is never a derivation of validity: the logical result of a law-making process is only a norm saying “The new norm ought to be valid.” Whether the new norm is in fact valid, is a different issue which is not dealt with by the PTL. This has serious consequences: Without this derivationStufenbaulehrecannot survive, and withoutStufenbaulehre, PTL cannot survive either. Some valuable parts of PTL might be used in other legal theories, but these are nothing but transplanted organs from the dead body of PTL whose heart-Stufenbaulehre-can no longer keep the body alive.

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