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gabb_03

How does targeted therapy work? | The American Cancer Society - 0 views

  • How does targeted therapy work?
  • Targeted therapy is used to keep cancer from growing and spreading. To become cancer cells, normal cells go through a process called carcinogenesis (car-sin-oh-JEN-eh-sis). Cancer cells may then grow into tumors or reproduce throughout a body system, like blood cancers do. Scientists have learned a lot about the molecules that are part of this process and the signals a cell gets to keep this process going. Targeted therapy disrupts this process. The drugs target certain parts of the cell and the signals that are needed for a cancer to develop and keep growing. These drugs are often grouped by how they work or what part of the cell they target.
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    how targeted therapy works
vikram1997

Nobelprize.org - 0 views

  • In October 1939, just after the outbreak of World War II in Europe, the President of the United States Franklin D. Roosevelt received a letter from physicist Albert Einstein and his Hungarian colleague Leo Szilard, calling to his attention the prospect that a bomb of unprecedented power could be made by tapping the forces of nuclear fission. The two scientists, who had fled from Europe in order to escape Nazism, feared that Hitler-Germany was already working on the problem. Should the Germans be the first to develop the envisaged "atomic bomb," Hitler would have a weapon at his disposal that would make it possible for him to destroy his enemies and rule the world.
  • To avoid this nightmare, Einstein and Szilard urged the government of the United States to join the race for the atomic bomb. Roosevelt agreed, and for the next four and half years a vast, utterly secret effort was launched in cooperation with the United Kingdom. Code-named "The Manhattan Project," the effort eventually employed more than 200,000 workers and several thousands scientists and engineers, many of European background. Finally, on July 16, 1945, the first atomic bomb was tested in the midst of the Alamogordo desert in New Mexico. Its power astonished even the men and women who had constructed it. As he witnessed the spectacular explosion, Robert Oppenheimer, the physicist who had directed the scientific work on the bomb, remembered a line from the Vedic religious text Bhagavad-Gita: "I am become death, the shatterer of worlds."
  • After the Japanese surrender on August 15, 1945, many people called for a ban on nuclear weapons in order to avoid a nuclear arms race and the risk of future catastrophes like the ones in Hiroshima and Nagasaki. Both the United States and the Soviet Union declared that they were in favor of putting the atomic bomb under foolproof international control. In spite of these declarations, the big powers were, in fact, never ready to give up their own nuclear weapons programs. By the end of 1946 it was clear to everybody that the effort to prevent a nuclear arms race had failed. Indeed, the Soviet Union had already launched a full-speed secret nuclear weapons program in an attempt to catch up with the United States. Thanks in part to espionage, the Soviet scientists were able to build a blueprint of the American fission bomb that was used against Nagasaki and to conduct a successful testing of it on August 29, 1949.
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  • By 1961, two more countries had developed and successfully tested nuclear weapons. United Kingdom had started its program during the Second World War in close co-operation with the United States, and the first British bomb was tested on October 3, 1952. On February 13, 1960, France followed suit. The French program received very little technological and scientific support from other countries. Four and a half years later, on October 16, 1964, China became the fifth nuclear power after having received only reluctant assistance from the Soviet Union.
  • In the early 1960s, many military experts and political leaders feared that the proliferation of nuclear weapons was bound to continue, and that within a decade or two a dozen additional countries were likely to cross the nuclear threshold. In an attempt to forestall such a development, the United States and the Soviet Union took the lead in negotiating an international agreement that would prohibit the further spread of nuclear weapons without banning the utilization of nuclear energy for peaceful purposes. The result was the Treaty on the Non-Proliferation of Nuclear Weapons, also referred to as the Non-Proliferation Treaty, or NPT, which opened for signature on July 1, 1968. By then, 21 countries in Latin America and the Caribbean had already established the world's first nuclear weapons-free zone by signing on to the Treaty of Tlatelolco.
  • When it came into force on March 5, 1970, the NPT separated between two categories of states: On the one hand, nuclear weapons states – that is, the five countries that were known to possess nuclear weapons at the time when the Treaty was signed (United States, Soviet Union, United Kingdom, France and China). On the other hand, non-nuclear weapons states – that is, all other signatories of the Treaty. According to its provisions, the nuclear weapons states on signing the NPT agree not to release nuclear weapons or in any other way help other states to acquire or build nuclear weapons. At the same time, the non-nuclear weapons states signatories agree not to acquire or develop "nuclear weapons or other nuclear explosive devices." In exchange for this self-denial, the nuclear weapons states promise to move toward a gradual reduction of their arsenals of nuclear weapons with the ultimate goal of complete nuclear disarmament.
  • The NPT was first signed by the United States, the United Kingdom, the Soviet Union together with 59 other countries. China and France acceded to the Treaty in 1992. In 1996, Ukraine, Belarus and Kazakhstan gave up their nuclear weapons, left over from the Soviet Union when it fell apart in 1991-92, and signed the NPT as non-nuclear weapons states parties. The NPT is now the most widely accepted arms control agreement. As of June 2003, all members of the United Nations except Israel, India, and Pakistan had signed the NPT. However, one signatory, North Korea, had recently threatened to withdraw from the Treaty.
  • As mentioned, the NPT distinguished between nuclear weapons states and non-nuclear weapons states as parties of the Treaty. However, from the very beginning there was in fact a third category of countries as well, namely, non-nuclear weapons states that for one reason or another had decided not to become parties of the NPT. Some countries, like Cuba, dismissed the NPT as an instrument that served to maintain the existing and, in their opinion, thoroughly unjust world order. Others simply wanted to reserve the option of developing their own nuclear arsenal: either to enhance their regional or international status, to deter military aggression or to underpin their political independence. Not surprisingly, most of the threshold states belonged to this group.
  • The first country outside the NPT to cross the nuclear threshold was India, which exploded a nuclear device in an atmospheric test in 1974. In 1998, both India and Pakistan conducted several nuclear underground tests, inviting a storm of international protests and some short-lived economic and political sanctions as well.
  • Meanwhile, the ending of white minority rule in South Africa in 1993 had led to the sensational disclosure that, in the mid-1980s, South Africa had developed and stockpiled a small number of nuclear weapons. The weapons had been dismantled and destroyed in the last years of apartheid because the white government feared that they might some day fall into the hands of militant black opposition groups and be used against the government. Subsequently, South Africa signed both the NPT (1991) and the CTBT (1996) as a non-nuclear weapons state.
laurenh468

Cellular Phones - 0 views

  • As noted above, the RF waves given off by cell phones don't have enough energy to damage DNA directly or to heat body tissues. Because of this, many scientists believe that cell phones aren't able to cause cancer. Most studies done in the lab have supported this theory, finding that RF waves do not cause DNA damage.
  • Some scientists have reported that the RF waves from cell phones produce effects in human cells (in lab dishes) that might possibly help tumors grow. However, several studies in rats and mice have looked at whether RF energy might promote the development of tumors caused by other known carcinogens (cancer-causing agents). These studies did not find evidence of tumor promotion.
  • Cell phones work by sending signals to (and receiving them from) nearby cell towers (base stations) using RF waves. This is a form of electromagnetic energy that falls between FM radio waves and microwaves. Like FM radio waves, microwaves, visible light, and heat, RF waves are a form of non-ionizing radiation. They don't have enough energy to cause cancer by directly damaging the DNA inside cells. RF waves are different from stronger (ionizing) types of radiation such as x-rays, gamma rays, and ultraviolet (UV) light, which can break the chemical bonds in DNA. At very high levels, RF waves can heat up body tissues. (This is the basis for how microwave ovens work.) But the levels of energy given off by cell phones are much lower, and are not enough to raise temperatures in the body.
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  • According to the Food and Drug Administration (FDA), which regulates the safety of radiation-emitting devices such as cell phones in the United States: "The majority of studies published have failed to show an association between exposure to radiofrequency from a cell phone and health problems."
  • According to the Federal Communications Commission (FCC): "There is no scientific evidence that proves that wireless phone usage can lead to cancer or a variety of other problems, including headaches, dizziness or memory loss. However, organizations in the United States and overseas are sponsoring research and investigating claims of possible health effects related to the use of wireless telephones." According to the Centers for Disease Control and Prevention (CDC): "Some… studies have suggested the possibility that long-term, high cell phone use may be linked to certain types of brain cancer. These studies do not establish this link definitively. Scientists will need to conduct more studies to learn more about this possible risk."  According to the National Institute of Environmental Health Sciences (NIEHS), which is currently conducting studies of the possible health effects of cell phones: "The weight of the current scientific evidence has not conclusively linked cell phones with any adverse health problems, but more research is needed." According to the National Cancer Institute (NCI): "Studies thus far have not shown a consistent link between cell phone use and cancers of the brain, nerves, or other tissues of the head or neck. More research is needed because cell phone technology and how people use cell phones have been changing rapidly."
gabb_03

What is targeted therapy? | American Cancer Society - 0 views

  • What is targeted therapy?
  • As researchers have learned more about the gene changes in cells that cause cancer, they have been able to develop drugs that target these changes. Treatment with these drugs is often called targeted therapy. Targeted therapy drugs, like any drug used to treat cancer, are technically considered “chemotherapy.” But targeted therapy drugs do not work in the same ways as standard chemotherapy drugs. They are often able to attack cancer cells while doing less damage to normal cells by going after the cancer cells’ inner workings—the programming that sets them apart from normal, healthy cells. These drugs tend to have different (and often less severe) side effects than standard chemotherapy drugs. Targeted therapies are used to treat many kinds of diseases. Here we will focus on their use to treat cancer. In the past, only a few cancers could be treated with targeted therapy, but now these drugs are used to treat many different types of cancer. Targeted therapies are a major focus of cancer research today. Many future advances in cancer treatment will probably come from this field.
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    what is targeted therapy
daym2015

HowStuffWorks "Nuclear Catastrophe and Reactor Shutdown" - 0 views

  • Plants such as Japan's Fukushima-Daiichi facility, Russia's Chernobyl and the United States' Three Mile Island remain a black eye for the nuclear power industry, often overshadowing some of the environmental advantages the technology has to offer. You can read more about exactly what happened in How Japan's Nuclear Crisis Works.
mbaron2015

Radiotracer and Radiopharmaceutical Chemistry - Advancing Nuclear Medicine Through Inno... - 0 views

  • In fact, one can trace the major advances in nuclear medicine directly to research in chemistry.
  • 20 million nuclear medicine procedures using radiopharmaceuticals and imaging instruments are carried out in hospitals in the United States alone each year to diagnose disease and to deliver targeted treatments. These techniques have also been adopted by basic and clinical scientists in dozens of fields (e.g., cardiology, oncology, neurology, psychiatry) for diagnosis and as scientific tools. For example, many pharmaceutical companies are now developing radiopharmaceuticals as biomarkers for new drug targets to facilitate the entry of their new drugs into the practice of health care and to objectively examine drug efficacy at a particular target relative to clinical outcome (Erondu et al. 2006).
  • progress in synthetic organic and inorganic chemistry laid the groundwork for dozens of compounds labeled with positron emitters or single photon emitters, which are now used in many clinical specialties.
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  • FDG-PETTumors and some organs, such as the brain, use glucose as a source of energy. FDG (Sidebar 2.2) is a fluorine-18-labeled derivative of glucose (fluorodeoxyglucose) which is used with positron emission tomography (PET) to provide a map of where glucose is metabolized in the body. Because tumors, as well as the brain and the heart, all use glucose as a source of energy, FDG is widely used in cancer diagnosis and in cardiology, neurology, and psychiatry. FDG is now widely available to hospitals throughout the United States and the world from a network of regional commercial cyclotron/FDG distribution centers (Figure 6.1). With the current large infrastructure of commercial cyclotron/FDG distribution centers, many chemists are developing other highly targeted fluorine-18-labeled compounds to take advantage of this unique network to broaden the use of PET for making health care decisions. The translation of FDG from the chemistry laboratory into a practical clinical tool had its roots in government-supported research in hot atom chemistry (see Chapter 5), cyclotron targetry, biochemistry, synthetic chemistry, nuclear chemistry, and radiochemistry that was integrated with engineering and automation (Fowler and Ido 2002).
  • The first section (6.3.1) summarizes five priority areas with broad public health impact where radiopharmaceuticals could serve as scientific and clinical tools leading to major breakthroughs in health care and basic understanding of human biology. The second section (6.3.2) describes technologies and methods currently being explored that could enable innovations in radiopharmaceutical development and advances in these five priority areas.
  • Cancer Biology and Targeted Radionuclide Therapy.
  • Neuroscience, Neurology and Psychiatry
  • Drug Development.
  • Cardiovascular Disease
  • Genetics and Personalized Medicine.
  • Currently, chemists working in the areas of molecular imaging and targeted radionuclide therapy are focused on designing and synthesizing radiopharmaceuticals with the required bioavailability and specificity to act as true tracers targeting specific cellular elements (e.g., receptors, enzymes, transporters, antigens, etc.) in healthy human subjects and in patients. Goals are to make labeling chemistry occur faster, more efficiently, and at smaller and smaller scales to give labeled compounds of very high specific activity that can act as true tracers.4
  • specific activity is critical for imaging receptors present at a copy number of 1,000 per cell, but less of an issue with receptors such as the epidermal growth factor receptor that are present at a concentration of millions per cell.
  • Two high research priorities that are under investigation are carbon-11 and fluorine-18 chemistry and peptide and antibody labeling.
  • Of particular importance is research on the design and development of radiotracers that are more broadly applicable to common pathophysiological processes, which may be more useful and more readily commercialized (e.g., targets involved in inflammation and infection, angiogenesis, tissue hypoxia, mitochondrial targets, cell signaling targets, and targets associated with diabetes, obesity, metabolic syndrome, or liver disease).
  • For example, MIBG, used initially mainly for assessment of neuroendocrine tumors, is now showing promise in early diagnosis of heart failure, a major health and economic issue in the United States. It is important to keep in mind that any new developments in targeted radionuclide therapy require access to research radionuclides (see Chapters 4 and 5
  • Four major impediments—some of which are elaborated further in other chapters of the report—stand in the way of scientific and medical progress and the competitive edge that the United States has held for more than 50 years:
  • Lack of Support for Radiopharmaceutical R&D.
  • Shortage of Trained Chemists and Physician Scientists
  • Inappropriate Regulatory Requirements
  • Limited Radionuclide Availability
  • 6.5. RECOMMENDATIONSThe committee formulated two recommendations to meet the future needs for radiopharmaceutical development for the diagnosis and treatment of human disease and to overcome national impediments to their entry into the practice of health care. RECOMMENDATION 1 : Enhance the federal commitment to nuclear medicine research. Given the somewhat different orientations of the DOE and the National Institutes of Health (NIH) toward nuclear medicine research, the two agencies should find some cooperative mechanism to support radionuclide production and distribution; basic research in radio nuclide production, nuclear imaging, radiopharmaceutical/radiotracer and therapy development; and the transfer of these technologies into routine clinical use. Implementation Action 1A1: A national nuclear medicine research program should be coordinated by the DOE and NIH, with the former emphasizing the general development of technology and the latter disease-specific applications. Implementation Action 1A2: In developing their strategic plan, the agencies should avail themselves of advice from a broad range of authorities in academia, national laboratories and industry; these authorities should include experts in physics, engineering, chemistry, radiopharmaceutical science, commercial development, regulatory affairs, clinical trials, and radiation biology. RECOMMENDATION 2: Encourage interdisciplinary collaboration. DOE-OBER should support collaborations between basic chemistry and physics laboratories, as well as multi-disciplinary centers focused on nuclear medicine technology development and application, to stimulate the flow of new ideas for the development of next-generation radiopharmaceuticals and imaging instrumentation.
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    NuclearMedicine, Radiotracers
smartalecm

HowStuffWorks "Nuclear War and the Atmosphere" - 0 views

  • If sufficient ash from burning cities and forests ascended into the sky, it could effectively work as an umbrella, shielding large portions of the Earth from the sun. If you diminish the amount of sunlight that makes its way to the surface, then you diminish the resulting atmospheric temperature -- as well as potentially interfere with photosynthesis.
laurenh468

ANS / Public Information / Resources / Radiation Dose Chart - 0 views

  • The average dose per person from all sources is about 620 mrems per year. It is not, however, uncommon for any of us to receive less or more than that in a given year (largely due to medical procedures we may undergo). International Standards allow exposure to as much as 5,000 mrems a year for those who work with and around radioactive material.
gabb_03

Questions about chemotherapy - 0 views

  • What is chemotherapy?
  • Chemotherapy is the use of strong drugs to treat cancer. You will often hear chemotherapy called “chemo,” (key-mo) but it’s the same treatment. Chemo was first used to treat cancer in the 1950s. It has helped many people live full lives. The chemo drugs your doctor or nurse gives you have been tested many times. Research shows they work to help kill cancer cells.
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    what is chemotherapy
vikram1997

The Iran Case: Addressing Why Countries Want Nuclear Weapons | Arms Control Association - 0 views

  • Iran’s possible development of nuclear weapons has now come front and center in U.S. foreign policy, as well as in consideration overall of preventing the spread of weapons of mass destruction. It has assumed particular importance because of its potential to reshape the security and politics of an already turbulent and critical region. In the middle of the Middle East, such a capability would at the very least lead to a basic reassessment by countries near and far of a full range of security, political, and other issues. As the saga of a widely presumed but not admitted Iranian nuclear weapons program unfolds, with its on-again, off-again character, something else is happening: the need for a reassessment of nonproliferation—both how to prevent proliferation and what to do if prevention fails. There is dwindling confidence that a country bent on developing nuclear weapons can forever be prevented from doing so by the now-traditional technological safeguards. In particular, it appears less possible to block the indigenous development of either plutonium or highly enriched uranium, the essential materials for nuclear weapons. Talent and knowledge are not a constraint, and access to fissionable materials may be an ever decreasing one to a country’s nuclear ambitions.
  • Most importantly, we need to ask why Iran or any other country would want to acquire nuclear weapons in the first place. Then we must see whether and, within appropriate limits, how the country in question can be dissuaded from developing those weapons. The recent Iranian pause in its enrichment activities allows the West, particularly the United States, the opportunity to explore this possibility before either resorting to military force or merely fretting that Iran is on the path to the destabilizing development of nuclear weapons.
  • To be sure, the United States and its allies have reasons to be bothered about Iran’s behavior, such as its support for terrorist groups such as Hezbollah. But Iran also has reason to be concerned about its security. Its principal antagonist, the United States, for many years not only practiced its dual containment policy against Iran (and Iraq) but also supported expatriate groups bent on overthrowing the regime in Tehran, including through violent means. Regime change in Tehran has been a recurrent theme in U.S. policy as it has been consistently in the policy of Israel, which also strongly supported the U.S. invasion of Iraq. Iran was accorded a place in the U.S. “axis of evil” and is now even more vulnerable than only a few years ago to nearby U.S. military power. However legitimate these U.S. policies and actions may be, along with the animosity toward Iran of some key regional countries, they do provide an objective basis for Iranian security concerns.
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  • One frequently expressed concern is that Iran would consider its nuclear weapons capability to be held in trust for the Islamic world or would give custody of a weapon to someone else, perhaps even a terrorist group. Such an outcome is theoretically possible, but not very probable. With one notable and quickly regretted exception—Soviet transfer of some U-235 to China in the 1950s—no country with bomb-making fissionable materials has knowingly transferred them to anyone else.
  • More useful to consider is the role that nuclear weapons would play in shaping post-nuclear Iran’s relationships with its neighbors—friends and foes. When all is said and done, such weapons would have little military utility except for deterrence. This would operate at four levels: to deter a conventional attack from a non-nuclear regional power; to deter an openly nuclear regional state—today only including Pakistan and India; to deter Israel; or to deter a major external power, notably the United States but, in theory at least, also including Russia.
  • The first case is obvious: no country with just conventional arms is likely to try the patience of a nuclear power. But in the other three cases, “proportional deterrence” would come into play. Originally developed by France, this doctrine holds that a relatively less-capable nuclear power such as Iran can deter a much stronger nuclear power (the United States, Russia, Pakistan, India, Israel) if it is viewed as able and willing to destroy “value targets” in the attacking nation even while it is being obliterated. This complex doctrine can be summarized as the “death throes” of a country under nuclear or even extreme conventional attack
  • Such a doctrine depends on the potential attacker such as the United States or Israel calculating that the targets in its own country that would be destroyed in retaliation would be more “valuable” to it than the benefit (military or political) of annihilating Iran. Of course, proportional deterrence can only succeed if the potential retaliation is credible, hence the need for a survivable second-strike capability. The threat of retaliation must not be so precise that the original attacking nation can calculate with precision whether the game is worth the candle (uncertainty principle). There should also be a margin for the leadership of the attacked nation to over-respond (irrationality principle). All these ideas were worked out in detail during the Cold War.
  • Nevertheless, as with all issues involving nuclear weapons, psychology and politics are critical elements. Indeed, if they were not—if the world had not witnessed Hiroshima and Nagasaki—we would likely have seen much more proliferation over the past 60 years, as many analysts long predicted, or even the further use of nuclear weapons in war.
  • As things now stand in the Middle East and are likely to stand for the foreseeable future, a nuclear-armed Iran would change the politics and the security of the region dramatically in terms of perceptions. The point need hardly be spelled out. Further, even if regional and outside countries could in time adjust to a nuclear-armed Iran, judged from today, it is highly unlikely that Iran would be permitted to gain such a capability. The United States, Israel, or perhaps some third-party would likely use whatever means necessary to prevent Iran from ever getting into that position.
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    What happens if Iran gets bomb?
daym2015

Nuclear Reactors | Nuclear Power Plant | Nuclear Reactor Technology - 0 views

  • A nuclear reactor produces and controls the release of energy from splitting the atoms of certain elements. In a nuclear power reactor, the energy released is used as heat to make steam to generate electricity. (
  • nuclear reactor produces and controls the release of energy from splitting the atoms of certain elements. In a nuclear power reactor, the e
wizardbrown

Nuclear reactor - Wikipedia, the free encyclopedia - 0 views

  • A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Nuclear reactors are used at nuclear power plants for electricity generation and in propulsion of ships. Heat from nuclear fission is passed to a working fluid (water or gas), which runs through turbines. These either drive a ship's propellers or turn electrical generators.
  • When a large fissile atomic nucleus such as uranium-235 or plutonium-239 absorbs a neutron, it may undergo nuclear fission. The heavy nucleus splits into two or more lighter nuclei, (the fission products), releasing kinetic energy, gamma radiation, and free neutrons. A portion of these neutrons may later be absorbed by other fissile atoms and trigger further fission events, which release more neutrons, and so on. This is known as a nuclear chain reaction. To control such a nuclear chain reaction, neutron poisons and neutron moderators can change the portion of neutrons that will go on to cause more fission.[2] Nuclear reactors generally have automatic and manual systems to shut the fission reaction down if monitoring detects unsafe conditions.[3] Commonly-used moderators include regular (light) water (in 74.8% of the world's reactors), solid graphite (20% of reactors) and heavy water (5% of reactors). Some experimental types of reactor have used beryllium, and hydrocarbons have been suggested as another possibility.[2][not in citation given]
gabb_03

Photodynamic Therapy - 0 views

  • What is photodynamic therapy?
  • Photodynamic therapy or PDT is a treatment that uses special drugs, called photosensitizing agents, along with light to kill cancer cells. The drugs only work after they have been activated or “turned on” by certain kinds of light. PDT may also be called photoradiation therapy, phototherapy, or photochemotherapy. Depending on the part of the body being treated, the photosensitizing agent is either put into the bloodstream through a vein or put on the skin. Over a certain amount of time the drug is absorbed by the cancer cells. Then light is applied to the area to be treated. The light causes the drug to react with oxygen, which forms a chemical that kills the cells. PDT might also help by destroying the blood vessels that feed the cancer cells and by alerting the immune system to attack the cancer. The period of time between when the drug is given and when the light is applied is called the drug-to-light interval. It can be anywhere from a couple of hours to a couple of days, depending on the drug used
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    photodynamic therapy
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