Mechanical waves transfer energy through a medium and include transverse, longitudinal, and surface waves. The Doppler effect describes how the frequency of a wave is changed relative to an observer based on their motion. Doppler echocardiography uses ultrasound to examine the heart and blood flow by detecting changes in frequency from reflected sound waves, allowing determination of flow speed and direction. It is a non-invasive procedure with benefits over more invasive testing for diagnosing cardiovascular conditions.
Parts of the Electrical System
Electrical activity of the heart
Electrical Signals and Blood Flow
Four Steps of Cardiac Conduction
Spread of Excitation Through theHeart Muscle
Parts of the Electrical System
Electrical activity of the heart
Electrical Signals and Blood Flow
Four Steps of Cardiac Conduction
Spread of Excitation Through theHeart Muscle
this presentation explains what is action potential, how it is initiated.
it deals with short notes and brief description on the various processes that undergoes in the action potential
this presentation will help you out to summarize and conclude important points.
regulation of cardiac activity is given in brief along with the cardiac diseases. For diseases, just pictures are added you need to go through the explanation separately so that pictures will make you to explain it easily.
An electric current is the rate of flow of electric charge past a point or region. An electric current is said to exist when there is a net flow of electric charge through a region. In electric circuits this charge is often carried by electrons moving through a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionized gas (plasma).
this presentation on cellular electrophysiology carry the information of electrical properties of biophysiology in cellular level. i hope it help you all.
this presentation explains what is action potential, how it is initiated.
it deals with short notes and brief description on the various processes that undergoes in the action potential
this presentation will help you out to summarize and conclude important points.
regulation of cardiac activity is given in brief along with the cardiac diseases. For diseases, just pictures are added you need to go through the explanation separately so that pictures will make you to explain it easily.
An electric current is the rate of flow of electric charge past a point or region. An electric current is said to exist when there is a net flow of electric charge through a region. In electric circuits this charge is often carried by electrons moving through a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionized gas (plasma).
this presentation on cellular electrophysiology carry the information of electrical properties of biophysiology in cellular level. i hope it help you all.
Doppler Effect ultrasound is a non invasive procedure by which high frequency sound sound waves are used to visualize the blood vessels where by the red indicate as the arteries and blue indicates as veins.
Doppler Effect is the apparent change in frequency and wavelength when the observer and source are in relative motion
M4 ndt me 367 introductiontoultrasonictestingHareesh K
This presentation explains the basics of ultrasonic inspection.Different practical aspects and various types of techniques are explained detail in this module.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
2. A mechanical wave is a wave that is an oscillation of m
atter, and therefore transfers energy through a medium.
While waves can move over long distances, the movem
ent of the medium of transmission—the material—is limit
ed. Therefore, oscillating material does not move far fro
m its initial equilibrium position. Mechanical waves trans
port energy. This energy propagates in the same directio
n as the wave. Any kind of wave (mechanical or electro
magnetic) has a certain energy. Mechanical waves can b
e produced only in media which possess elasticity and in
ertia.
A mechanical wave requires an initial energy input. Once this
initial energy is added, the wave travels through the medium
until all its energy is transferred. In contrast, electromagnetic
waves require no medium, but can still travel through one.
3. There are three types of mechanical waves: transverse
waves, longitudinal waves, and surface waves
Transverse waves cause the medium to vibrate at a right an
gle to the direction of the wave or energy being carried by
the medium.
Longitudinal waves cause the medium to vibrate parallel t
o the direction of the wave. It consists of multiple compre
ssions and rarefactions. The rarefaction is the farthest dist
ance apart in the longitudinal wave and the compression i
s the closest distance together.
This type of wave travels along a
surface that is between two media.
An example of surface wave would
be waves in a pool, or in an ocean,
lake, or any other type of water bo
dy. There are two types of surface
waves, namely Rayleigh waves an
d Love waves.
4. That the frequency measured by an observer may be diff
erent from that emitted from the wave source due to the
relative motion between them is called Doppler Effect.
For the mechanical waves (we simply call them sound i
n the following text), classical treatment can give satisfie
d result that has been given by many textbooks and disc
ussed. It is:
uo, us, and v are the speeds of observer, sound source, and sound in
the medium respectively; fo and fs are the frequency measured by th
e observer and emitted by the sound source respectively.
5. If a source is stationary, it will emit sound waves that propagate
out from the source as shown below. As the receiver moves tow
ards the source, it will detect the sound coming from the source
but each successive sound wave will be detected earlier than it
would have if the receiver were stationary, due to the motion of t
he receiver in the LOS. Thus the frequency that each successiv
e wave front would be detected would be changed by this relativ
e motion where:
The observer’s motion causes him
to intercept more waves per second
than he would if he were standing
still.
6. Equation is only valid when the relative velocity is along t
he line connecting the wave source and the observer (w
hich is called wave vector). When this is not the case, uo
and us should be replaced with their velocity component
s that are parallel to the wave vector,. Therefore, Eq. is
replaced with
When the source and observer are approaching to each other, uo and us
are positive; otherwise, they are negative. One should notice that the moti
on of observer and or source has different effect on frequency change.
7. When the source of light is moving away from the
observer the wavelength of the emitted light will
appear to increase. We call this a redshift. Red because the
wave length is the longest.
When the source of light is moving towards the
observer the wavelength of the emitted light will
appear to decrease. We call this a Blueshift.
8. For sound, only the velocity component along the wave
vector direction affects the frequency. This is so called
longitudinal Doppler Effect. When observer and source
move perpendicularly to the wave vector direction (trans
versely), i.e., θ1 = θ2 = 90°, then fo = fs. So there is no
so called transverse Doppler Effect for sound waves.
In the case that the wave source and observer are approaching/re
ceding to each other, fo actually changes with time because the
angles change with time
9. For the electromagnetic waves (we simply call them light
in the following text) we have similar Doppler effect but
the different equation because
1) propagation of light doesn’t need medium so the light
velocity relative to the observer is always the same;
2) the period of the light may change for the observers
at different initial frame of reference (and time dilatio
n)
10. Doppler echocardiography is a procedure that uses ultraso-
und technology to examine the heart or blood vessels. An ech
ocardiogram uses high frequency sound waves to create an
image of the heart while the use of Doppler technology allow
s determination of the speed and direction of blood flow by
utilizing the Doppler effect.
An echocardiogram can, within certain limits, produce accura
te assessment of the direction of blood flow and the velocity o
f blood and cardiac tissue at any arbitrary point using the Dop
pler effect. One of the limitations is that the ultrasound beam
should be as parallel to the blood flow as possible.
Mitral valve
11. Unlike 1D Doppler imaging, which can only provide one-
dimensional velocity and has dependency on the beam t
o flow angle, 2D velocity estimation using Doppler ultras
ound is able to generate velocity vectors with axial and
lateral velocity components. 2D velocity is useful even if
complex flow conditions such as stenosis and bifurcation
exist. There are two major methods of 2D velocity estim
ation using ultrasound: Speckle tracking and crossed be
am Vector Doppler, which are based on measuring the ti
me shifts and phase shifts respectively.
12. Vector Doppler is a natural extension of the traditional 1
D Doppler imaging based on phase shift. The phase shif
t is found by taking the autocorrelation between echoes f
rom two consecutive firings. The main idea of Vector
Doppler is to divide the transducer into three apertures:
one at the center as the transmit aperture and two on ea
ch side as the receive apertures. The phase shifts meas
ured from left and right apertures are combined to give t
he axial and lateral velocity components. The positions a
nd the relative angles between apertures need to be tun
ed according to the depth of the vessel and the lateral p
osition of the region of interest.
13. Speckle tracking, which is a well-established method in v
ideo compression and other applications, can be used to
estimate blood flow in ultrasound systems. The basic ide
a of speckle tracking is to find the best match of a certai
n speckle from one frame within a search region in subs
equent frames. The decorrelation between frames is one
of the major factors degrading its performance. The dec
orrelation is mainly caused by the different velocity of pix
els within a speckle, as they do not move as a block. Thi
s is less severe when measuring the flow at the center, a
s the changing rate of the velocity is the lowest. The flow
at the center usually has the largest velocity magnitude,
called peak velocity. It is the most needed information in
some cases, such as diagnosing stenosis.
14. It should be noted here that there are no standards for
the display of color Doppler. Some laboratories show art
eries as red and veins as blue, as medical illustrators us
ually show them, even though some vessels may have p
ortions flowing towards and portions flowing away from t
he transducer. This results in the illogical appearance of
a vessel being partly a vein and partly an artery. Other la
boratories use red to indicate flow toward the transducer
and blue away from the transducer. Still other laboratorie
s prefer to display the sonographic Doppler color map m
ore in accord with the prior published physics with the re
d shift representing longer waves of echoes (scattered)
from blood flowing away from the transducer; and with
blue representing the shorter waves of echoes reflecting
from blood flowing toward the transducer
Colour Doppler scan of the common carotid artery
15. The main benefit of Doppler ultrasound is that it is less in
vasive than other procedures used to identify these type
s of medical problems. The ultrasound is perform on the
outside of the body and is not painful. Some discomfort
may be experienced as the transducer is used, but it is
often minimal. Because the ultrasound is not invasive, th
ere are fewer risks to using it as a diagnostic test and m
any patients are able to have serious conditions detecte
d without having to spend extensive time in the hospital.