Radioactivity - Science topic
Radioactivity is the spontaneous transformation of a nuclide into one or more different nuclides, accompanied by either the emission of particles from the nucleus, nuclear capture or ejection of orbital electrons, or fission. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Questions related to Radioactivity
Based on my sources gallium 68 undergoes a beta + decay. I've read that if an isotope has "too many neutrons" it undergoes beta - decay; if it has "too many protons" it undergoes beta + decay. Initially, I thought: "gallium 68 has 31 protons and 37 neutrons, so it has too many neutrons" (comparing it to a 1:1 ratio). But, if that was the correct reasoning it should undergo a beta - decay.
Therefore, I'm now thinking that to establish if a nucleus has "too many neutrons" or "too many protons" you have to compare it to the most stable isotope (could that be it?!). If we take the most stable isotope (gallium 69) as a reference:
Gallium 69: 31 protons and 38 neutrons;
Gallium 68: 31 protons and 37 neutrons...
...then we can say it has too many protons (that is, compared to the ratio found in the most stable isotope). Is that right or what am I missing?
Thank you in advance!
Since all the nuclie of Radioactive isotope have the same energy, I would like to know why they decay randomly and not all of them decay in the same time.
Suppose a lab experiment gave evidence that the DNA or RNA code for bacteria are stored in radioactive chemical atoms, because the atomic decays are followed by the appearance of protozoa in a test tube of sterile chemical building blocks. Would this be an evidence for a cosmic mind that formed the atoms containing these genetic codes?
Question related to materials development technology...
In the autoradiography experiments in which tritiated compounds are injected, nuclei of cells use to appear electrodense. But I am not sure if this means that the nuclei incorporated the label or that nuclei appear black (as a radioactive background) when you take the radiography.
I attach a paper as an example. The researchers injected tritiated methionine intraperitoneally in rats and assessed its incorporation in the cells of the retina.
I am working on a study to evaluate the content radioactive isotopes in agricultural soil. I have the concentrations of Th232, U238, Cs137 and K40 and I want to know if the concentration is harmful for crops and humans or not.
Following a nuclear disaster, people in the fallout zone should eat stable iodine to prevent their body from absorbing radioactive iodine. All current recommendations are based on a 1- or 2-dose regime.
You take 1 or 2 doses, total, no matter how long you are exposed to radioactive iodine.
However, the same sources also say that 24 h after taking iodine, the protective effect has fallen to 70%. 48 hours after intake, the protective effect is only 25%. 
Logically, you should continue taking stable iodine for as long as you are being exposed to radiactive iodine, but I can't find a single source anywhere with long-term dosage information.
Does anyone know where I can find out more about appropriate doses over weeks, or months of exposure?
Zdenko frani; Iodine prophylaxis And nuclear Accidents; Institute for medical research and Occupational health, zagreb, Croatia; Received april 1999
I would like to simulate the activation-transmutation reactions occuring in a steel during high-energy proton irradiation. Furthermore, I am also interested in simulating the radioactivity from the irradiated specimens during cooldown and the time required for safe handling of the specimens.
Which application / code is best applicable for these kind of calculations? Also, it would be better to have comments on the advantages and limitations of these packages.
Thank you for your support.
The use of environmental tracers that are relevant for groundwater and surface water interactions constitutes a powerful tool for understanding the source, flow and mixing dynamics of water resource systems through their imprint on the system.
I am trying to study the effect of my inhibitor in transcription initiation in a viral RNA polymerase.
My time points have to be from 15 sec to 10 min and I have to take samples every 15 sec for first 1 to 2 minutes. Hence it is not possible if I use a radioactive isotope to measure the reaction.
I was wondering if there is some non radioactive method to visualise IVT in real time.
Thanks for the answers
we can not to use radioactivity more, and we are looking for a kit that we can use to labeled the specific dna to find and confirmed a mutant fungi strain.
As is known, high radioactive plutonium is produced as a waste product from the rods in nuclear power plants (which needs to be stored subterranean for thousands of years): What are the means (or current efforts/researches) to reuse this plutonium as a source to generate energy, instead?
I want to analyze the radioactive trace content of leaf and rock sample. How do I prepare the leaf and rock samples before taking it to laboratory for analysis and which of the device (method) should I use for the analysis?
When measuring gamma spectra from the decay of a radioactive nucleus, I observe 3 peaks in the spectrum. The databases indicate that during the decay of this nucleus, there are only 2 lines that lie in a cascade. The third observed peak is cumulative and is approximately 10% of the first or second peak. What is the possibility of dividing the third peak into contributions from the first and second transitions?
I want to know if I need to do anything to the cells before I can use the equipment mentioned in my question when the cells are still radioactive due to treatment with radioactive molecules?
Will it cause damage to the equipment?
Will I need to wait for the radioactivity to be below detection level before I can use the equipment?
Above your imagination, is there really an increase in the radioactivity of natural radioactive isotopes in the sewage water of hospitals. And if it is in studies or research, I hope you send it to me to benefit me in my study
Is there a change in the radioactivity before the sewage sludge treatment and after the treatment?
I wish to provide me with research and studies on the subject
How to measure normal radioactivity in phosphate fertilizers by examining gamma spectra
Does the resulting radioactivity be large? Are there studies on the subject? I hope to provide them with them as they are useful to me with my studies
I know that it detects radioactivity in the area by reading the concentrations of Uranium, Thorium and Potassium. So if it depends on the radioactivity of these 3 radioelements, can it be used to detect skarn deposits, even though some skarn deposits have low radioactivity
We have been using HPGe detectors for evaluating the level of natural and artificial radionuclides in different kinds of environmental samples. Parallelly, we also provide radioactivity testing services to ensure that there are no consequences triggered due to the consumption of highly radioactive food materials. We usually use certified reference material (CRM) collected from IAEA for calibration, performance evaluation (PE), method validation (MV), and QC. We are planning to collect a CRM of milk powder spiked with Cs-137...but could not find it anywhere? Could anyone of you please help me find it? It is urgent for us as we are working on getting ISO17025 accreditation by this year.
I measured the dose rate at different distances for different radioactive samples.
How can i calculate the uncertainty in the activity from these measurements?
I calculated the activity from the equation stated below;
H= 1.5*10^-15 * A * E * n *B * exp(-mu*d) / r^2
- H = [Sv/h]
- 1.5*10^-15 is a conversion factor
- A the Activity [Bq]
- E the energy of Cobalt60 with corresponding n the number of photons/desintegrations
- B Buildup factor of shielding material
- exp(-mu*d) the attenuation factor of the shielding material
- r distance from the sample [m]
I can plot H versus r , is it possible to just use the uncertainty of the distance and measured H here, or should i implement the different theoretical factors to obtain the uncertainty in A?
I hope it is a clear story, if not let me know.
I'm wondering how multiple sources can be calculated. Are there any standard rules for this, like specific addition or subtraction or averaging rules?
To given an example; different point sources relative close to each other. Let's say a distance of 10 cm between two sources, with activity A and B. And now i measure the dose rate somewhere in between those points. Are both sources contributing equally if A=B, and thus the total activity is A+B or do i have to average it.
I hope it is clear what i'm wondering, if not let me know
The construction of the basins in the isotope treatment hospitals must be at a certain depth from under the ground .. to prevent the radioactive leakage of water .. I hope to provide me with sufficient information about the isotope treatment hospitals for cancer patients and how the radioactive water is treated .. Inside the basins and what international standards are To build these ponds
I am making a simulation of energy deposited of some radioactive sources in scintillation detector. I have some results, but I don't have the same distribution energy between experimental spectra and simulated spectra. I do not know why.
For instance, the spectra of Cs-137 is shown. However, it does not have the same resolution.
Someone who can help me how to improve the simulation.
The scintillation detector is of NaI:Tl.
I am trying to characterize the release kinetics of a small molecule from alginate beads. The small molecule is very simple and very challenging to detect with methods other than mass spec . To avoid using MS since it is expensive, I am considering getting a radiolabeled version of it and detecting it. I'm deciding between a 14C version and a 3H version. No one in my lab has extensive experience with radioactivity and I am unsure of some things that might be obvious for people who work with it extensively. For instance, are you supposed to mix the radiolabeled version with the normal small molecule and, if so, how do you know how much to put in? I'm also wondering what the lower limit of detection for each would be and how to detect the concentration. I've read a bit about liquid scintillation counting but is that the only method or are there plate readers that work for radioactive substances. I'd appreciate any input on the topic as I feel a little lost. Thank you!
In part of my project, i have to extract cell nucleus after cells lysis in order to measure nuclear radioactivity and also cytoplasm+membrane fraction radioactivity.
For this, it is important to check if my cytoplasm+membrane fraction and nuclear fraction are pure.
Would you have a check technic to advise me on how to do it ?
I have a personal question about the safety of working with Radioactive Sulphur. I am planning to start pulse-chase labeling experiments to study protein synthesis. Sulphur-35 is a low energy beta emitter. I'd like to know if anybody has any inputs on working with Sulphur-35 while pregnant: is it dangerous? Is it okay? Risks for the fetus (I am not pregnant right now, but would like to know the risks just-in-case). Any inputs will be greatly appreciated!
In my early education I was taught radioactive decay was - in general - not affected by environmental variables. This seems to have been disputed in recent years. I'm curious about the current state of the debate. Are there good reasons to think radioactive decay rates are affected by environmental variables?
I have an issues with identifying a radioactive sample from pegmatite mine. I was guessing is Allanite by the look at the field and it has pretty high concentration of Uranium Thorium, however the Raman cant identify it. I have 20 other samples which are not Radioactive and it is just works fine. But with this sample is eater fluorescence, or it s identify the material impossibly wrong. Also the most important is that it hits a big hole in the sample. Especially when I try to identify some white crystals. The whole is slightly bigger than the leser width but it also creates spiral like cracks in a 3x bigger radius. Can someone explain why is that happening? or is there anything to do with radioactivity? I heard that raman is perfect for uranium identification, maybe I use the wrong settings?
Q and A are parameters used for standardization and safety of drugs in pharmacology. Quality assurance is an integral part of traditional medicine, which certifies that it delivers the required quantity of quality drug. The standardization parameters are authentication, foreign matters, organoleptic evaluation, microscopy, volatile matters, extractive values, ash values, radioactive contaminants, microorganisms, pesticide residue, refractive index, chromatographic profiles and marker components.
a sample is a piece from a fuel element containing fuel exposed in nuclear reactor. We cut transversely the fuel element. what is happen with spectrum if the uranium emit gamma rays?
will i require a collimator for investigation of gamma attenuation or the same experimental set up can be performed for both gamma attenuation and radioactivity check .I am using gamma ray spectrometer us using Nal(Tl) detector
Leucine uptake assay is widely used for bacterial production. But I have three concerns (1) Why Leucine (not other amino acids) is used and (2) In case of environmental samples, Leucine may be present in water and in that case, how to say that Hot leucine (radioactive Leucine) was only incorporated into the bacterial proteins or how to negate the uptake of environmental leucine from incorporation? (3) Does all proteins incorporate Leucine in case of bacteria?
I'm currently performing cytotoxicity tests using Chromium 51 (PerkinElmer) with a half-life of 27,7 days, let's say 28 days. If I have to add 21ul of the product to label 1x10*6 cells with 100uCi, how much product do I have to add to the same amount of cells to obtain the same effect 3 weeks later?
I think it is 21ul + (3/4)*21ul = 36,75ul
Is this calculation correct?
its atomic number is not too high. So what kind of mathematical or physical constraint on its nuclear structure breaks it so easily? Why doesn't it have any natural stable isotope?
If it's one isotope with nearly equal neutron and proton number be produced, why that would not be stable?
The worldwide average natural dose to humans is about 2.4 mSv per year. Some areas with sizable populations have much higher than average background radiation levels. The highest are found primarily in (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China) and are due to high concentrations of radioactive minerals in the soil. What technique should be used to determine the possible long term health effects for the people living in these high natural background area ?
I am doing a pulse chase assay following radioactive methionine/ cysteine uptake. Over time I see processing of protein (67KDa to 45 KDa) following pull down with anti-HA coated magnetic beads (my protein is tagged with HA at the C-term end). Along with the signal at the correct spots, I see very strong signal at the very bottom of the gel. I wonder what could this be? Any comment would be greatly appreciated. I am attaching a picture of my autoradiograph.
I am planning to study global protein synthesis levels in presence and absence of certain chemical compounds. I know that the gold standard for this purpose is the S35-methionine pulse chase labeling. However, I am not so enthusiastic about working with radioactive chemicals when there are nonradioactive alternatives available these days. I've come across the Click-iT HPG/Alexa Fluor Azide and Click-iT AHA/Alexa Fluor alkyne assays from Thermofisher.
Are there any other fluorescence based assays available to determine global protein synthesis (quantitatively) preferably a nonradioactive way and something that I can simply measure in a cellplate reader? Thank you!
We have a shrimp sample from IAEA for proficiency test and as per the requirement of IAEA we want to identify and quantify radioactivity in that sample. We have taken a sample count for 90000 sec.
Suppose we got the gross count for K-40 (1460.822 keV) is 1.03E+04 with an area uncertainty of about 121.69.
Before the measurement of the sample, the gamma background at laboratory site was determined with an identical empty plastic container used in the sample measurement.
The background gross count for 1460.822 keV was found as 8.71E+03 with an area uncertainty of about 111.49. We can easily calculate the net count rate from the mentioned information.
But my question is how to calculate Net count rate uncertainty.
Je travail sur les eaux thermales de la région ouest d’Algérie sur leur qualité physico-chimie_chimique et bactériologique et voudrais avoir une idée sur la qualité radiologique de ces eaux.
Les régions d’études : Saida, Mascara et Tlemcen
Radiosurgery, the therapy of brain tumors, has long been made using a so called Gamma Knife with high activity sealed sources such as Cobalt-60. Nowadays the therapy can also be made with a linear accelerator such as a Cyber Knife. What are your experiences? Can you share advantages and disadvantages of each system. At the end do you think that the use of radioactive sources is still (medically)justified for radiosurgery given the alternative of a Linear accelerator?
After the three big nuclear accidents (TMI, Chernobyl, Fukushima), radiophobia has become one of the most difficult obstacles to using nuclear energy. While many attempts have been made to resolve this issue, such as providing information and education on nuclear energy, the radiophobia seems to get even larger in some countries as time goes by. Under the circumstances, what do you think would be the best way to reduce the public's fear of radioactivity?
Refer to the following two articles that provide comprehensive knowledge on the public's perception of radiation and its risk:
I have solution of two different salts with different solubility. How to separate them by cristallisation in range of volume 500 microliter? One salt is in bulk scale, in hundrets of milligramms, another salt is no carrier addad amount of radioactive material, it means 10E-7 gramms, approximately. The main problem is for me the remaining amount of activity on the surface of the wet cristalls.
Hi ! Dear all !
Put in place mine exploitation or exploration has impact on environmental security (human being, croads or vegetation, animals etc). Environmental exposition by naturally occurring radioactive materials (NORMs) because of this activity must be the great worry. Is there any right norm or right technological process that can safe health in the environment where explotation of mine has put in place. Thanks for your answer !
please I am looking for someone who can help me for interpretation of the results of radioactive isotope analysis in thermal waters ..
I'm trying to tag a type of WBCs and then inject them to mice and track the cells to see were they sit after 12-36 hrs. I now luciferases and radioactive isotopes are two of my options but i wanted to know if I can use any of fluorescent dyes such as MitoTracker deep red with Excitation⁄Emission (nm):644⁄665 orrr?
Or any other suggestions?
In a paper published this week in nature, researchers at XENON1T reported that they had observed radioactive decay of xenon 124. Xenon 124 went to tellurium 124, and the atomic number went from 54 to 52.
Some previous conversions are not practical. For example, when converting radioactive decay model. The fuzzy solutions become negative which is not practical to represent number of particles.
I am currently searching for an antibody against phosphorylated ABCA1 for western blot. I have a Novus anti-ABCA1 antibody (NB400-105) that is working quite well, but cant seem to find a good one for the phosphorylated protein.
I found a couple online (http://www.emdmillipore.com/US/en/product/Anti-phospho-ABCA1-%28Ser2054%29%2C-clone-EPR2485%2C-Rabbit-Monoclonal-Antibody,MM_NF-MABS734 and http://biossusa.com/store/bs-12956r-hrp.html), but cant find any papers that used them, so Im not sure if they're any good. And all papers I've seen that looked at phospho-ABCA1 used either 32-P or ABCA1 IP and then phospho-serine to determine levels of phospho-ABCA1. We cant use radioactive labeling in our lab, so I may try the IP protocol, but would prefer to just find an antibody against p-ABCA1.
If anyone knows of a good antibody for this, or a paper that used one, please let me know!
Thank you so much for your help!
I´m trying to set up a protocol for the evaluation of the internalization of a radiolabelled antibody; all the protocols that I´ve found suggest to lysate the cells and then to measure the internalized fraction of an antibody.
Is this a fundamental step? Or it´s just possible to wash the cells, collect them and measure the radioactivity with the gamma-counter?
Spherical symmetry doesn't permit the field configuration different from radial one. From the other side the circulation theorem implies tangent field with non zero rotor. The solution of Maxwell equation gives loss of symmetry and a hole in the sphere for ' charge supplying wire'. What's the matter?
I am assuming decomposition is far more complex than simple decay (radioactive isotope). Because decomposition includes physical, chemical and all other processes.
If radioactivity is rapidly measured after collection in whole blood containaing clot activator (for serum), are there any analytical interference on beta counting measurements?
I want to perform some radio labeled transfer assays using Carbon 14 labeled amino acids. I know some sources e.g., PerkinElmer, Moravek for radioactive chemicals. If you know any other please let me know.
Thanks in advance!
I am trying to calculate radioactivity of organs after injecting radio-tracer into body by knowing injected radio-tracer activity and absorbed dose per unit activity. How can I calculate organ's radio activity.
For example : The injected radio activity of radio tracer that injected into human body is 80 MBq and absorbed dose of liver per unit administered(mGy/MBq) is 1.1E-03. How much will be the radio activity of of liver after injecting this radio-tracer? If it is time dependent, could you please explain by considering any time?
Thanks in advance,
- radioactive sources
- thickness need
- risk assessment
- build up factor
- effective atomic number
Age determination of unknown human bodies is important in the setting of a crime investigation or a mass disaster because the age at death, birth date, and year of death as well as gender can guide investigators to the correct identity among a large number of possible matches.
Do you think that this time can be extracted using the ratio of decay of radioactive carbon that turns nitrogen after death?
Rodents will receive calcium injection to specify preferred tissue distribution after my drug treatment. Measuring radioactivity from blood sample is fairly easy, is it feasible to determine tissue calcium de novo distribution from organs? Maybe tissue homogenisation followed by scintillation counting?
I'm speaking of this kind of magic that made radioactivity principles to be discovered. Untidy Becquerel, after an hard day of research, forgot 2 pieces of granite stone on a photographic plaque: that's how he got the first shot of radioactivity. Something he did not planned gave him the keys to understand radioactivity. Because he took the time to recognize his error, analyzed it and begun to plan a theory. At times, life is more generous even and at my humble level, I was so surprised to have shot an image, almost by chance, (because I thought it would be a nice tattoo) and without knowing what it meant, to get aware it was one of the central motifs of my historical-literary investigation: the logo of the famous Manutius family from Venice, who invented book edition: a dolphin rolled up on an anchor. Personally, it gave me the sensation to have entered by chance in Ali Baba's cavern (see my text Antonio Manutius aka Hassan Pacha Veneziano's library). Do you have personal episodes of magical incidents in your research? (Profitable errors, unpredictable things happening, unusual events that change the direction of the wind, etc.)
Can you suggest any method for the detection of RNA binding site in the protein without using radioactive substances.
Thanks in advance.
If I have a package with overalls (Anti c) contaminated with material radioactive inside. This come to contaminated area used by personnel in order to protect of radioactive contamination.
we take a smear the overall and send to the count room, in order to get the Isotopic, but I know that can to calculate with direct radiation, is true?
And we need to transport to the laundry.
I exposed some brain sections, which were treated with 3H-DAMGO, on an autoradiographic film, and as usual in this case, the exposure time was about 1 week.
Unfortunately, at the end I couldn't scan the films so I am wondering if I can expose the same slides to another film.
Tritium has a very low radioactivity but it should be pretty stable (I think, according to the half-life) so maybe after 1 week there is still going to be enough radioactivity so that I can expose the slides again, maybe for a longer time.
What do you think?
Thank you in advance.
Has anybody some experience doing this kind of experiments? We are trying to quantify glutamate uptake by human astrocytes using the method followed by Pines and Kanner in 1990, with tritiated glutamate.
We have some doubts regarding the methods used to quantify radiation. Is it better to use a scintillation counter or a microbeta? Does someone have a specific protocol to do so?
Thank you in advance!