Is it a tumor? Magnetic Resonance Imaging (MRI) can tell. Your head is full of tiny radio transmitters (the nuclear spins of the hydrogen nuclei of your water molecules). In an MRI unit, these little radios can be made to broadcast their positions, giving a detailed picture of the inside of your head.
Section summary
Radiopharmaceuticals are compounds that are used for medical imaging and therapeutics.
The process of attaching a radioactive substance is called tagging.
[link] lists certain diagnostic uses of radiopharmaceuticals including the isotope and activity typically used in diagnostics.
One common imaging device is the Anger camera, which consists of a lead collimator, radiation detectors, and an analysis computer.
Tomography performed with
-emitting radiopharmaceuticals is called SPECT and has the advantages of x-ray CT scans coupled with organ- and function-specific drugs.
PET is a similar technique that uses
emitters and detects the two annihilation
rays, which aid to localize the source.
Conceptual questions
In terms of radiation dose, what is the major difference between medical diagnostic uses of radiation and medical therapeutic uses?
One of the methods used to limit radiation dose to the patient in medical imaging is to employ isotopes with short half-lives. How would this limit the dose?
A neutron generator uses an
source, such as radium, to bombard beryllium, inducing the reaction
. Such neutron sources are called RaBe sources, or PuBe sources if they use plutonium to get the
s. Calculate the energy output of the reaction in MeV.
Neutrons from a source (perhaps the one discussed in the preceding problem) bombard natural molybdenum, which is 24 percent
. What is the energy output of the reaction
? The mass of
is given in
Appendix A: Atomic Masses , and that of
is 98.907711 u.
The purpose of producing
(usually by neutron activation of natural molybdenum, as in the preceding problem) is to produce
Using the rules, verify that the
decay of
produces
. (Most
nuclei produced in this decay are left in a metastable excited state denoted
.)
(a) Two annihilation
rays in a PET scan originate at the same point and travel to detectors on either side of the patient. If the point of origin is 9.00 cm closer to one of the detectors, what is the difference in arrival times of the photons? (This could be used to give position information, but the time difference is small enough to make it difficult.)
(b) How accurately would you need to be able to measure arrival time differences to get a position resolution of 1.00 mm?
The activities of
and
used in thyroid scans are given in
[link] to be 50 and
, respectively. Find and compare the masses of
and
in such scans, given their respective half-lives are 8.04 d and 13.2 h. The masses are so small that the radioiodine is usually mixed with stable iodine as a carrier to ensure normal chemistry and distribution in the body.
(a) Neutron activation of sodium, which is 100%
, produces
, which is used in some heart scans, as seen in
[link] . The equation for the reaction is
. Find its energy output, given the mass of
is 23.990962 u.
(b) What mass of
produces the needed 5.0-mCi activity, given its half-life is 15.0 h?
In economics, a perfect market refers to a theoretical construct where all participants have perfect information, goods are homogenous, there are no barriers to entry or exit, and prices are determined solely by supply and demand. It's an idealized model used for analysis,
When MP₁ becomes negative, TP start to decline.
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 •
Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of lab
Kelo
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 •
Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of labour (APL) and marginal product of labour (MPL)
Quantity demanded refers to the specific amount of a good or service that consumers are willing and able to purchase at a give price and within a specific time period. Demand, on the other hand, is a broader concept that encompasses the entire relationship between price and quantity demanded
Ezea
ok
Shukri
how do you save a country economic situation when it's falling apart
Economic growth as an increase in the production and consumption of goods and services within an economy.but
Economic development as a broader concept that encompasses not only economic growth but also social & human well being.
Shukri
production function means
Jabir
What do you think is more important to focus on when considering inequality ?
sir...I just want to ask one question... Define the term contract curve? if you are free please help me to find this answer 🙏
Asui
it is a curve that we get after connecting the pareto optimal combinations of two consumers after their mutually beneficial trade offs
Awais
thank you so much 👍 sir
Asui
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities, where neither p
Cornelius
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities,
Cornelius
Suppose a consumer consuming two commodities X and Y has
The following utility function u=X0.4 Y0.6. If the price of the X and Y are 2 and 3 respectively and income Constraint is birr 50.
A,Calculate quantities of x and y which maximize utility.
B,Calculate value of Lagrange multiplier.
C,Calculate quantities of X and Y consumed with a given price.
D,alculate optimum level of output .
the market for lemon has 10 potential consumers, each having an individual demand curve p=101-10Qi, where p is price in dollar's per cup and Qi is the number of cups demanded per week by the i th consumer.Find the market demand curve using algebra. Draw an individual demand curve and the market dema
suppose the production function is given by ( L, K)=L¼K¾.assuming capital is fixed find APL and MPL. consider the following short run production function:Q=6L²-0.4L³ a) find the value of L that maximizes output b)find the value of L that maximizes marginal product