Diagnosis and Treatment of Cervical Cancer A Review Diagnosis and Treatment of Cervical Cancer: A Review Cervical cancer is a type of malignancy emerging from cervix. This is a effect of cervical malignancy. CAUSES Contamination with a few sorts of HPV is the most serious danger element for cervical tumor, trailed by smoking.
Cervical Cancer Symptoms Signs Causes & Treatment. Cervical cancer is one of the most preventable and curable forms of cancer, as long as it is detected early and managed effectively. New diagnoses can be reduced in two ways, HPV vaccination and screening of the cervix with follow on treatment of early changes before cancer appears., Cervical cancer is different from cancer that begins in other regions of the uterus (uterine or endometrial cancer). If detected early, cervical cancer has a very high cure rate. Vaccination against HPVs, which are known to cause cervical cancer, is an effective preventive measure..
Cervical cancer is the fourth most common cancer in women worldwide. The primary risk factor for cervical cancer is human papillomavirus (HPV) infection. Start here to find evidence-based information on cervical cancer treatment, causes and prevention, screening, research, and statistics. Learn the symptoms and signs of cervical cancer and the medications used in treatment. Common symptoms and signs include discharge, abnormal vaginal bleeding, pelvic pain, and pain during intercourse. Pinpoint your symptoms and signs with MedicineNet's Symptom Checker.
What Are the Symptoms of Cervical Cancer? In the early stages, cervical precancers or cervical cancers cause no pain or other symptoms. That's why it's vital for women to get regular pelvic exams Cervical cancer forms in the interior lining of the cervix, the junction of the vagina and uterus. The development of cervical cancer is typically slow, and occurs over a period of years. The progression to cervical cancer begins with the development of precancerous changes in normal cells. Most of these changes, even if left untreated, will not progress to cancer.
What Are the Symptoms of Cervical Cancer? In the early stages, cervical precancers or cervical cancers cause no pain or other symptoms. That's why it's vital for women to get regular pelvic exams 8/19/2019 · Rates of cervical cancer have gone down in the United States. The Data Visualizations Tool provides detailed statistics. Low-Cost Screening CDC’s National Breast and Cervical Cancer Early Detection Program provides low-cost breast and cervical cancer screenings. Find out if you qualify
3/25/2019 · Cervical Cancer Causes and Risk Factors In addition to the main cause of cervical cancer, an HPV infection, there are several other risk factors that contribute to the disease: Smoking: Women who are infected with HPV and smoke cigarettes have a higher risk of cervical cancer. 8/19/2019 · Rates of cervical cancer have gone down in the United States. The Data Visualizations Tool provides detailed statistics. Low-Cost Screening CDC’s National Breast and Cervical Cancer Early Detection Program provides low-cost breast and cervical cancer screenings. Find out if you qualify
Cervical cancer begins with abnormal changes in the cervical tissue. Infection with human papillomavirus is the cause of almost all cervical cancers.Other known risk factors for cervical cancer include early sexual contact, multiple sexual partners, cigarette smoking, HIV infection and a weakened immune system, and taking oral contraceptives (birth control pills). Cervical Cancer Causes, Risk Factors, and Prevention. Learn about the risk factors for cervical cancer and what you might be able to do to help lower your risk. Early Detection, Diagnosis, and Staging. Know the signs and symptoms of cervical cancer. Find out how cervical cancer is …
Cervical cancer is a disease in which malignant (cancer) cells form in the tissues of the cervix. Human papillomavirus (HPV) infection is the major risk factor for cervical cancer. There are usually no signs or symptoms of early cervical cancer but it can be detected early with regular check-ups. Cervical cancer is a slowly progressive cancer usually caused by human papillomavirus (HPV), a sexually transmitted infection It generally does not cause symptoms until late stages, and it can be diagnosed with a Pap smear or a biopsy before symptoms appear.
Cervical cancer is the fourth most common cancer in women worldwide. The primary risk factor for cervical cancer is human papillomavirus (HPV) infection. Start here to find evidence-based information on cervical cancer treatment, causes and prevention, screening, research, and statistics. 1/12/2019 · Each year, more than half a million women are diagnosed with cervical cancer and the disease results in over 300 000 deaths worldwide. High-risk subtypes of the human papilloma virus (HPV) are the cause of the disease in most cases. The disease is largely preventable. Approximately 90% of cervical cancers occur in low-income and middle-income countries that lack organised screening and …
Q: What is cervical cancer? A: Cervical cancer is the growth of abnormal cells in the lining of the cervix. Cancer most commonly begins in the area of the cervix called the transformation zone (see page 6), but it may spread to tissues around the cervix, such as the vagina, … Cervical cancer is the fourth most common cancer in women worldwide. The primary risk factor for cervical cancer is human papillomavirus (HPV) infection. Start here to find evidence-based information on cervical cancer treatment, causes and prevention, screening, research, and statistics.
What is cervical cancer screening? Cervical cancer screening is used to find changes in the cells of the cervix that could lead to cancer.The cervix is the opening to the uterus and is located at the top of the vagina.Screening includes cervical cytology (also called the Pap test or Pap smear) and, for some women, testing for human papillomavirus (HPV). Cervical cancer kills 260,000 women annually, and nearly 85% of these deaths occur in developing nations, where it is the leading cause of cancer deaths in women. Disparities of health and poverty play a large role in this high mortality rate. Whereas routine Papanicolaou and human papillomavirus
What Are the Symptoms of Cervical Cancer? In the early stages, cervical precancers or cervical cancers cause no pain or other symptoms. That's why it's vital for women to get regular pelvic exams Cervical Cancer Causes, Risk Factors, and Prevention. Learn about the risk factors for cervical cancer and what you might be able to do to help lower your risk. Early Detection, Diagnosis, and Staging. Know the signs and symptoms of cervical cancer. Find out how cervical cancer is …
Cervical cancer is the fourth most common cancer in women worldwide. The primary risk factor for cervical cancer is human papillomavirus (HPV) infection. Start here to find evidence-based information on cervical cancer treatment, causes and prevention, screening, research, and statistics. What is cervical cancer screening? Cervical cancer screening is used to find changes in the cells of the cervix that could lead to cancer.The cervix is the opening to the uterus and is located at the top of the vagina.Screening includes cervical cytology (also called the Pap test or Pap smear) and, for some women, testing for human papillomavirus (HPV).
What Causes Cervical Cancer? Healthline. What causes cervical cancer? The cervix is a small, narrow, tube-like organ at the bottom of the uterus that connects to the vagina. The cervix is the passage through which sperm travels to the uterus and menstrual fluid flows out. It also dilates during labor to allow a baby to pass through the birth canal., Learn the symptoms and signs of cervical cancer and the medications used in treatment. Common symptoms and signs include discharge, abnormal vaginal bleeding, pelvic pain, and pain during intercourse. Pinpoint your symptoms and signs with MedicineNet's Symptom Checker..
Cervical Cancer Symptoms and Signs – Detect it as Early as. 1/7/1998 · The observed associations of less preva lent HPV types with cervical cancer have important implications for cervi cal cancer prevention strategies. [J Natl Cancer Inst 1998;90:43-9] Certain types of human papillomavirus (HPV) are currently recognized as the central etiologic factor of invasive cervical cancer (1,2) and of its precursor lesions https://en.wikipedia.org/wiki/Cervical_cancer_screening Cervical cancer is different from cancer that begins in other regions of the uterus (uterine or endometrial cancer). If detected early, cervical cancer has a very high cure rate. Vaccination against HPVs, which are known to cause cervical cancer, is an effective preventive measure..
What causes cervical cancer? Almost all cases of cervical cancer are caused by HPV. HPV is a very common virus that can be passed on through any type of sexual contact with a man or a woman. There are more than 100 types of HPV, many of which are harmless. But some types can cause abnormal changes to the cells of the cervix, which can What causes cervical cancer? Almost all cases of cervical cancer are caused by HPV. HPV is a very common virus that can be passed on through any type of sexual contact with a man or a woman. There are more than 100 types of HPV, many of which are harmless. But some types can cause abnormal changes to the cells of the cervix, which can
Cervical cancer screenings have saved thousands of lives by diagnosing alterations early enough to start an effective treatment. As you will see in this article, cervical cancer does not give out many obvious symptoms unless it is an advanced stage cancer that grows big enough or invades the CAUSES OF CERVICAL CANCER. 132 In Australia he still can, and does. As an employee of the Service, he is no longer a free agent-theoretically or otherwise. The difference, in pr... Download PDF . 173KB Sizes 0 Downloads 47 Views. Report. Recommend Documents. Causes of Cervical Cancer Causes of complications from cervical spine manipulation
Cervical cancer kills 260,000 women annually, and nearly 85% of these deaths occur in developing nations, where it is the leading cause of cancer deaths in women. Disparities of health and poverty play a large role in this high mortality rate. Whereas routine Papanicolaou and human papillomavirus What causes cervical cancer? Almost all cases of cervical cancer are caused by HPV. HPV is a very common virus that can be passed on through any type of sexual contact with a man or a woman. There are more than 100 types of HPV, many of which are harmless. But some types can cause abnormal changes to the cells of the cervix, which can
Cervical Cancer Causes, Risk Factors, and Prevention cancer.org 1.800.227.2345 Risk Factors A risk factor is anything that affects your chance of getting a€disease such as cancer. What causes cervical cancer? Almost all cases of cervical cancer are caused by HPV. HPV is a very common virus that can be passed on through any type of sexual contact with a man or a woman. There are more than 100 types of HPV, many of which are harmless. But some types can cause abnormal changes to the cells of the cervix, which can
CAUSES OF CERVICAL CANCER. 132 In Australia he still can, and does. As an employee of the Service, he is no longer a free agent-theoretically or otherwise. The difference, in pr... Download PDF . 173KB Sizes 0 Downloads 47 Views. Report. Recommend Documents. Causes of Cervical Cancer Causes of complications from cervical spine manipulation What causes cervical cancer? The cervix is a small, narrow, tube-like organ at the bottom of the uterus that connects to the vagina. The cervix is the passage through which sperm travels to the uterus and menstrual fluid flows out. It also dilates during labor to allow a baby to pass through the birth canal.
What Are the Symptoms of Cervical Cancer? In the early stages, cervical precancers or cervical cancers cause no pain or other symptoms. That's why it's vital for women to get regular pelvic exams What causes cervical cancer? Almost all cases of cervical cancer are caused by HPV. HPV is a very common virus that can be passed on through any type of sexual contact with a man or a woman. There are more than 100 types of HPV, many of which are harmless. But some types can cause abnormal changes to the cells of the cervix, which can
1/7/1998 · The observed associations of less preva lent HPV types with cervical cancer have important implications for cervi cal cancer prevention strategies. [J Natl Cancer Inst 1998;90:43-9] Certain types of human papillomavirus (HPV) are currently recognized as the central etiologic factor of invasive cervical cancer (1,2) and of its precursor lesions What Are the Symptoms of Cervical Cancer? In the early stages, cervical precancers or cervical cancers cause no pain or other symptoms. That's why it's vital for women to get regular pelvic exams
cal cancer screening are proven effective strategies to eliminate deaths from cervical cancer. USG as-sistance to help end cervical cancer deaths would begin to address this disparity between the causes of death and the focus on global health funding. ACS CAN calls on Congress to direct U.S. global health appropriations to support a campaign to Cervical cancer is the fourth most common cancer in women worldwide. The primary risk factor for cervical cancer is human papillomavirus (HPV) infection. Start here to find evidence-based information on cervical cancer treatment, causes and prevention, screening, research, and statistics.
1/7/1998 · The observed associations of less preva lent HPV types with cervical cancer have important implications for cervi cal cancer prevention strategies. [J Natl Cancer Inst 1998;90:43-9] Certain types of human papillomavirus (HPV) are currently recognized as the central etiologic factor of invasive cervical cancer (1,2) and of its precursor lesions cal cancer screening are proven effective strategies to eliminate deaths from cervical cancer. USG as-sistance to help end cervical cancer deaths would begin to address this disparity between the causes of death and the focus on global health funding. ACS CAN calls on Congress to direct U.S. global health appropriations to support a campaign to
What causes cervical cancer? Almost all cases of cervical cancer are caused by HPV. HPV is a very common virus that can be passed on through any type of sexual contact with a man or a woman. There are more than 100 types of HPV, many of which are harmless. But some types can cause abnormal changes to the cells of the cervix, which can Cervical cancer is one of the most preventable and curable forms of cancer, as long as it is detected early and managed effectively. New diagnoses can be reduced in two ways, HPV vaccination and screening of the cervix with follow on treatment of early changes before cancer appears.
Cervical cancer is a slowly progressive cancer usually caused by human papillomavirus (HPV), a sexually transmitted infection It generally does not cause symptoms until late stages, and it can be diagnosed with a Pap smear or a biopsy before symptoms appear. 11/3/2015 · Cervical cancer is the second most common cancer in women in low- and middle-income countries (LMICs), with an estimated 530,000 new cases each year. More than 270,000 women die from cervical cancer annually, with >85% of these deaths occurring in LMICs.
Cervical Cancer A Preventable Death PubMed Central (PMC). PDF Among the numerous human papillomavirus (HPV) types, only types 16 and 18 have been formally classified as human carcinogens. Causes of Cervical Cancer in the Philippines: a Case-Control, Cervical cancer most commonly occurs in women over 35 years of age. It rarely occurs before the age of 25 years. In New Zealand about 160 women are diagnosed with cervical cancer each year and approximately 50 women die from the disease..
Cervical Cancer Stages Signs Treatment & Causes. Cervical cancer kills 260,000 women annually, and nearly 85% of these deaths occur in developing nations, where it is the leading cause of cancer deaths in women. Disparities of health and poverty play a large role in this high mortality rate. Whereas routine Papanicolaou and human papillomavirus, Cervical cancer forms in the interior lining of the cervix, the junction of the vagina and uterus. The development of cervical cancer is typically slow, and occurs over a period of years. The progression to cervical cancer begins with the development of precancerous changes in normal cells. Most of these changes, even if left untreated, will not progress to cancer..
Find out how the My CancerIQ cervical cancer risk assessment works and receive your personalized action plan report so you can manage your risk factors and reduce your risk. Human papillomavirus. Persistent infection with human papillomavirus (HPV) causes an estimated 30% of the total global cancer burden. HPV has been identified in 100% of cervical cancer cases and a significant proportion of anal, vaginal, vulval, penile and oropharyngeal cancers.. HPV is a common, and usually asymptomatic, sexually transmitted infection.
cal cancer screening are proven effective strategies to eliminate deaths from cervical cancer. USG as-sistance to help end cervical cancer deaths would begin to address this disparity between the causes of death and the focus on global health funding. ACS CAN calls on Congress to direct U.S. global health appropriations to support a campaign to 1/12/2019 · Each year, more than half a million women are diagnosed with cervical cancer and the disease results in over 300 000 deaths worldwide. High-risk subtypes of the human papilloma virus (HPV) are the cause of the disease in most cases. The disease is largely preventable. Approximately 90% of cervical cancers occur in low-income and middle-income countries that lack organised screening and …
6/25/2019 · Cervical cancer can be life-threatening if it goes undetected or untreated. But how do you know if you have cervical cancer? We explain what causes cervical cancer, including the role of HPV. We Cervical cancer is the fourth most common cancer in women worldwide. The primary risk factor for cervical cancer is human papillomavirus (HPV) infection. Start here to find evidence-based information on cervical cancer treatment, causes and prevention, screening, research, and statistics.
Cervical cancer is different from cancer that begins in other regions of the uterus (uterine or endometrial cancer). If detected early, cervical cancer has a very high cure rate. Vaccination against HPVs, which are known to cause cervical cancer, is an effective preventive measure. Release date: March 1, 2019Expiration date: February 29, 2020Estimated time of completion: 1 hourClick here to start this CME/MOC activity.ABSTRACTThe human papillomavirus (HPV) causes most cases of cervical cancer. Healthcare providers can help prevent this cancer by recommending HPV vaccination when appropriate, regularly screening women for cervical cancer, and following up on abnormal test
Cervical cancer kills 260,000 women annually, and nearly 85% of these deaths occur in developing nations, where it is the leading cause of cancer deaths in women. Disparities of health and poverty play a large role in this high mortality rate. Whereas routine Papanicolaou and human papillomavirus Learn the symptoms and signs of cervical cancer and the medications used in treatment. Common symptoms and signs include discharge, abnormal vaginal bleeding, pelvic pain, and pain during intercourse. Pinpoint your symptoms and signs with MedicineNet's Symptom Checker.
6/25/2019 · Cervical cancer can be life-threatening if it goes undetected or untreated. But how do you know if you have cervical cancer? We explain what causes cervical cancer, including the role of HPV. We Q: What is cervical cancer? A: Cervical cancer is the growth of abnormal cells in the lining of the cervix. Cancer most commonly begins in the area of the cervix called the transformation zone (see page 6), but it may spread to tissues around the cervix, such as the vagina, …
What is cervical cancer screening? Cervical cancer screening is used to find changes in the cells of the cervix that could lead to cancer.The cervix is the opening to the uterus and is located at the top of the vagina.Screening includes cervical cytology (also called the Pap test or Pap smear) and, for some women, testing for human papillomavirus (HPV). Cervical cancer is a disease in which malignant (cancer) cells form in the tissues of the cervix. Human papillomavirus (HPV) infection is the major risk factor for cervical cancer. There are usually no signs or symptoms of early cervical cancer but it can be detected early with regular check-ups.
Causes of Cervical Cancer 690 undergraduate and graduate levels ". In some of these economically more fortunate countries there have lately been localised increases in the inc... Cervical cancer screenings have saved thousands of lives by diagnosing alterations early enough to start an effective treatment. As you will see in this article, cervical cancer does not give out many obvious symptoms unless it is an advanced stage cancer that grows big enough or invades the
Causes of cervical cancer. Almost all cases of cervical cancer are caused by persistent infection with some high-risk types of the human papillomavirus (HPV); this is the biggest risk factor for cervical cancer. The other main risk factor for cervical cancer is smoking. 1/12/2019 · Each year, more than half a million women are diagnosed with cervical cancer and the disease results in over 300 000 deaths worldwide. High-risk subtypes of the human papilloma virus (HPV) are the cause of the disease in most cases. The disease is largely preventable. Approximately 90% of cervical cancers occur in low-income and middle-income countries that lack organised screening and …
Diagnosis and Treatment of Cervical Cancer: A Review Cervical cancer is a type of malignancy emerging from cervix. This is a effect of cervical malignancy. CAUSES Contamination with a few sorts of HPV is the most serious danger element for cervical tumor, trailed by smoking. 11/3/2015 · Cervical cancer is the second most common cancer in women in low- and middle-income countries (LMICs), with an estimated 530,000 new cases each year. More than 270,000 women die from cervical cancer annually, with >85% of these deaths occurring in LMICs.
Cervical cancer The Lancet. Cervical cancer screenings have saved thousands of lives by diagnosing alterations early enough to start an effective treatment. As you will see in this article, cervical cancer does not give out many obvious symptoms unless it is an advanced stage cancer that grows big enough or invades the, Cervical cancer is a sexually transmitted disease caused by the human papillomavirus (HPV), especially HPV-16 and -18. Of the half million new cases of cervical cancer reported yearly, 20% occur.
Cervical Cancer Symptoms Causes Diagnosis and Treatment. What causes cervical cancer? Almost all cases of cervical cancer are caused by HPV. HPV is a very common virus that can be passed on through any type of sexual contact with a man or a woman. There are more than 100 types of HPV, many of which are harmless. But some types can cause abnormal changes to the cells of the cervix, which can https://en.wikipedia.org/wiki/Cervical_intraepithelial_neoplasia Diagnosis and Treatment of Cervical Cancer: A Review Cervical cancer is a type of malignancy emerging from cervix. This is a effect of cervical malignancy. CAUSES Contamination with a few sorts of HPV is the most serious danger element for cervical tumor, trailed by smoking..
Causes of Cervical Cancer 690 undergraduate and graduate levels ". In some of these economically more fortunate countries there have lately been localised increases in the inc... Cervical cancer begins with abnormal changes in the cervical tissue. Infection with human papillomavirus is the cause of almost all cervical cancers.Other known risk factors for cervical cancer include early sexual contact, multiple sexual partners, cigarette smoking, HIV infection and a weakened immune system, and taking oral contraceptives (birth control pills).
6/25/2019 · Cervical cancer can be life-threatening if it goes undetected or untreated. But how do you know if you have cervical cancer? We explain what causes cervical cancer, including the role of HPV. We Cervical cancer most commonly occurs in women over 35 years of age. It rarely occurs before the age of 25 years. In New Zealand about 160 women are diagnosed with cervical cancer each year and approximately 50 women die from the disease.
Cervical Cancer Causes, Risk Factors, and Prevention. Learn about the risk factors for cervical cancer and what you might be able to do to help lower your risk. Early Detection, Diagnosis, and Staging. Know the signs and symptoms of cervical cancer. Find out how cervical cancer is … Causes of Cervical Cancer 690 undergraduate and graduate levels ". In some of these economically more fortunate countries there have lately been localised increases in the inc...
8/19/2019 · Rates of cervical cancer have gone down in the United States. The Data Visualizations Tool provides detailed statistics. Low-Cost Screening CDC’s National Breast and Cervical Cancer Early Detection Program provides low-cost breast and cervical cancer screenings. Find out if you qualify Cervical cancer kills 260,000 women annually, and nearly 85% of these deaths occur in developing nations, where it is the leading cause of cancer deaths in women. Disparities of health and poverty play a large role in this high mortality rate. Whereas routine Papanicolaou and human papillomavirus
Cervical cancer is a disease in which malignant (cancer) cells form in the tissues of the cervix. Human papillomavirus (HPV) infection is the major risk factor for cervical cancer. There are usually no signs or symptoms of early cervical cancer but it can be detected early with regular check-ups. Human papillomavirus. Persistent infection with human papillomavirus (HPV) causes an estimated 30% of the total global cancer burden. HPV has been identified in 100% of cervical cancer cases and a significant proportion of anal, vaginal, vulval, penile and oropharyngeal cancers.. HPV is a common, and usually asymptomatic, sexually transmitted infection.
Cervical cancer screenings have saved thousands of lives by diagnosing alterations early enough to start an effective treatment. As you will see in this article, cervical cancer does not give out many obvious symptoms unless it is an advanced stage cancer that grows big enough or invades the Cervical cancer begins with abnormal changes in the cervical tissue. Infection with human papillomavirus is the cause of almost all cervical cancers.Other known risk factors for cervical cancer include early sexual contact, multiple sexual partners, cigarette smoking, HIV infection and a weakened immune system, and taking oral contraceptives (birth control pills).
Cervical cancer screenings have saved thousands of lives by diagnosing alterations early enough to start an effective treatment. As you will see in this article, cervical cancer does not give out many obvious symptoms unless it is an advanced stage cancer that grows big enough or invades the 11/3/2015 · Cervical cancer is the second most common cancer in women in low- and middle-income countries (LMICs), with an estimated 530,000 new cases each year. More than 270,000 women die from cervical cancer annually, with >85% of these deaths occurring in LMICs.
Cervical Cancer Causes, Risk Factors, and Prevention cancer.org 1.800.227.2345 Risk Factors A risk factor is anything that affects your chance of getting a€disease such as cancer. 12/12/2018 · A doctor can remove those lesions almost painlessly. If done in time, the lesions will not be able to develop into cervical cancer. Vaccination of adolescent girls against HPV (the virus that causes most cases of cervical cancer) and regular cervical screenings can reduce the chances of …
7/24/2017 · Risks and causes. Find out about the risks and causes of cervical cancer, including the human papilloma virus (HPV). Cervical cancer is the 13 th most common cancer in women in the UK.. Anything that increases your risk of getting a disease is called a risk factor. Cervical cancer is different from cancer that begins in other regions of the uterus (uterine or endometrial cancer). If detected early, cervical cancer has a very high cure rate. Vaccination against HPVs, which are known to cause cervical cancer, is an effective preventive measure.
Cervical carcinoma in situ is also referred to as stage 0 cervical cancer. It’s noninvasive, which means the cancerous cells are confined to the surface of your cervix and haven’t penetrated Cervical cancer forms in the interior lining of the cervix, the junction of the vagina and uterus. The development of cervical cancer is typically slow, and occurs over a period of years. The progression to cervical cancer begins with the development of precancerous changes in normal cells. Most of these changes, even if left untreated, will not progress to cancer.
Cervical cancer most commonly occurs in women over 35 years of age. It rarely occurs before the age of 25 years. In New Zealand about 160 women are diagnosed with cervical cancer each year and approximately 50 women die from the disease. CAUSES OF CERVICAL CANCER. 132 In Australia he still can, and does. As an employee of the Service, he is no longer a free agent-theoretically or otherwise. The difference, in pr... Download PDF . 173KB Sizes 0 Downloads 47 Views. Report. Recommend Documents. Causes of Cervical Cancer Causes of complications from cervical spine manipulation