The challenge of keeping and getting new customers drives the development of new practices to meet the consumption needs of increasingly tends to micro-segmentation of product and consumer market. The new consumption ...The challenge of keeping and getting new customers drives the development of new practices to meet the consumption needs of increasingly tends to micro-segmentation of product and consumer market. The new consumption habits of brazilians brought new prospects for market. The objective of this paper is to develop of a dynamic vehicle routing system supported by the behavior of urban traffic in the city ofSao Paulo using Neuro Fuzzy Network. The methodology of this paper consists in the capture of relevant events that interfere with the flow of traffic of the city of Sao Paulo and implementation of a Fuzzy Neural Network trained with these events in order to foresee the traffic behavior. The system offers three labels of hierarchical routing, thus is possible to consider not only the basic factors of routing, but too external factors that directly influence on the flow of traffic and the disruption which may be avoided in large cities, through alternative routes （dynamic vehicle routing）. Predicting the behavior of traffic represents the strategic level routing, dynamic vehicle routing is the tactical level, and routing algorithms to the operational level. This paper will not be discussed the operational level.展开更多
Neuroplasticity is a condition that is present from birth, being found in the central and peripheral nervous system, in both physiological and pathological terms. Based on the findings, therapeutic and non-therapeutic...Neuroplasticity is a condition that is present from birth, being found in the central and peripheral nervous system, in both physiological and pathological terms. Based on the findings, therapeutic and non-therapeutic attempts were tested on spinal cord trauma to recover locomotor function below the level of the injury. The work defined and showed other forms of the term neuroplasticity, talk about some pathological and non-pathological conditions, and, finally, show neuroplasticity and some of its treatments in the spinal cord injury process. A narrative literature review from 2000 to 2020 of the PubMed platform was conducted and analysis of two books for the elaboration of this <span>work. Animal/human studies were included that addressed pathologies,</span> forms of treatment for spinal trauma, and qualis from B1 to A1. Pre-2000 articles, which addressed neuroplasticity only to understand the molecular mechanisms and articles that were not in English, were excluded. As a result, the main molecules and structures that inhibit neuroplasticity were found, and, based on their knowledge, forms of treatments were developed to inhibit these molecules and structures to assist in neuroplasticity and assist in possible functional recovery. It can be concluded that the physiological barriers are already being overcome by the most recent forms of treatment and that soon new studies may propose a form of treatment that is protocoled for all patients.展开更多
BACKGROUND Inflammatory bowel diseases(IBDs)are chronic diseases that demand continuous interaction between patients and healthcare providers.Quality of care(QoC)is a factor that contributes to a patient’s adherence ...BACKGROUND Inflammatory bowel diseases(IBDs)are chronic diseases that demand continuous interaction between patients and healthcare providers.Quality of care(QoC)is a factor that contributes to a patient’s adherence to treatment and its success.AIM To evaluate QoC in patients from a single IBD reference center.METHODS This cross-sectional study included 133 patients from a single Brazilian IBD public health center.QoC was evaluated through the QoC Through the Eyes of Patients with IBD(QUOTE-IBD)questionnaire(based on patient perspectives),which measures eight dimensions of care.We compared QoC among patients with Crohn’s disease and ulcerative colitis and analyzed the clinical and psychological factors associated with QoC satisfaction.Clinical evaluations assessed disease characteristics,quality of life,anxiety,and depression levels.RESULTS Sixty-nine patients with Crohn’s disease and 64 with ulcerative colitis were interviewed.The mean age was 37.26 years±13.05 years,and 63.91%of the patients were women.The mean duration of the disease was 8.44 years±7.59 years,where most patients were in remission(70.31%of patients with ulcerative colitis and 62.32%with Crohn’s disease).The total QoC score of the sample was 8.61 years±1.31 points,indicating that the QoC provided by the center was unsatisfactory.According to univariate logistic regression,patients with Crohn’s disease had higher satisfaction rates than those with ulcerative colitis[odds ratio(OR):2.746;95%confidence interval(CI):1.360-5.541;P=0.0048]and patients on infliximab(OR:2.175;95%CI:1.037-4.562;P=0.0398).CONCLUSION Patients from the IBD public center reported good doctor-patient relationships,but had problems related to the healthcare structure.Evaluation of healthcare centers is of paramount to improve QoC for the patients involved.展开更多
The objective of this study was characterizing the gelatin from the chicken feet by FTIR （Fourier transform infrared） spectroscopy. Two gelatin samples were prepared for the experiment which were extracted of 200 g ...The objective of this study was characterizing the gelatin from the chicken feet by FTIR （Fourier transform infrared） spectroscopy. Two gelatin samples were prepared for the experiment which were extracted of 200 g of chicken feet by a thermal bath of 4% acetyl acid solution at 60 ℃. A commercial gelatin was used to compare the results. FTIR spectra of gelatin samples were recorded using a Nicolet iS5 FTIR spectrometer equipped with an ATR/iD3 with argon horizontal cell in which the spectra were varied in the range of 400-4,000 cm1 at 16 ~C. The results showed that FTIR spectra of the chicken feet gelatin had the most with the vibration peak at wave numbers of 1,652.01 cm~ to the amide I, of 1,539.87 cm1 to the amide II, of 1,241.29 cm~ to the amide III, of 2,923.72 cm-~ to the amide B and of 3,399.56 cm~ to the amide A. The collagen composition of the chicken feet gelatins was twotimes larger than the commercial gelatin and the vibration bands to beef gelatin have been different from chicken feet gelatins. This demonstrates that chicken feet gelatins are very good nutritional quality when compared to the commercial gelatin.展开更多
The Web development has drastically changed the human interaction and communication, leading to an exponential growth of data generated by users in various digital media. This mass of data provides opportunities for u...The Web development has drastically changed the human interaction and communication, leading to an exponential growth of data generated by users in various digital media. This mass of data provides opportunities for understanding people’s opinions about products, services, processes, events, political movements, and organizational strategies. In this context, it becomes important for companies to be able to assess customer satisfaction about their products or services. One of the ways to evaluate customer sentiment is the use of Sentiment Analysis, also known as Opinion Mining. This research aims to compare the efficiency of an automatic classifier based on dictionary with the classification by human jurors in a set of comments made by customers in Portuguese language. The data consist of opinions of service users of one of the largest Brazilian online employment agencies. The performance evaluation of the classification models was done using Kappa index and a Confusion Matrix. As the main finding, it is noteworthy that the agreement between the classifier and the human jurors came to moderate, with better performance for the dictionary-based classifier. This result was considered satisfactory, considering that the Sentiment Analysis in Portuguese language is a complex task and demands more research and development.展开更多
Objective: The aim of the study was to make a literature review on counseling and family education about the care with tracheostomy and develop a guidance booklet for parents about the cautions in handling tracheostom...Objective: The aim of the study was to make a literature review on counseling and family education about the care with tracheostomy and develop a guidance booklet for parents about the cautions in handling tracheostomy tubes at home. Methods: This research is based on literature review from 1992 to 2012, realized from October of 2011 to August 2012, through the following databases: medline, lilacs, scielo and sibinet USP, with the elaboration of a guidance booklet for parents, about home care of tracheostomized children. Results: We elaborated a guidance booklet for parents, about the care of tracheostomized children and all were described according to literature review. Conclusion: According to the literature review family education in the care of tracheostomized children is essential so that caregivers have full autonomy to safely and effectively conduct the necessary techniques in their homes.展开更多
Purpose: Children with liver impairment are likely to develop changes in autonomic nervous function and delay in motor development. The assessment and identification of these dysfunctions may allow an appropriate phys...Purpose: Children with liver impairment are likely to develop changes in autonomic nervous function and delay in motor development. The assessment and identification of these dysfunctions may allow an appropriate physiotherapeutic care. Method: Cross sectional study of 18 infants, 11 controls and 7 infants (post-liver transplantation) with an average age of 10 ± 4.5 months, was evaluated in pre- and post-liver transplant. All infants underwent to assessments of motor skills, body composition, chest and abdominal motion, and cardiac autonomic modulation was measured by heart rate variability. Results: Motor delay and malnutrition were found in all infants. The gravity index (PELD)—pediatric end-stage liver disease—showed a negative correlation with the Alberta Infant Motor Scale (r = 0.83, p = 0.01). In addition, reduced parasympathetic modulation was demonstrated by the rMSSD, SD1 and ApEn, pre- and post-transplant. Conclusion: Infants with liver disease, even after transplantation, have delay in motor development, as well as changes in their nutritional and autonomic dysfunction.展开更多
The paper was monitored the conductivity （g.L＂l of NaCI）, the absorbances values （Abs） and the amount of TOC （total organic carbon）, before and after five consecutive dyeings made with reuse water, obtained fro...The paper was monitored the conductivity （g.L＂l of NaCI）, the absorbances values （Abs） and the amount of TOC （total organic carbon）, before and after five consecutive dyeings made with reuse water, obtained from treated effluent by UV/H202 photocatalysis. All rates of decolorization were above 92%, the removal of total organic carbon was above 89% in all treatments and the economy of NaCI was from 3.10 in the first recipe, 3.17 in the second, 3.49 in the third, 3.79 in the fourth and 4.05 in the fifth recipe. The five dyeings compared with same dyeings made with deionized water presented a color deviation （AE＊） below 1. The conventional dyeings would consume 80 L/kg against 40 L/kg used in the dyeing process proposed in this study, representing a great economy of water, with no discharge of effluents.展开更多
Endurance running became a mass phenomenon throughout the 1980s around the world. Therefore, we wanted to investigate the participation and performance trends of runners in a half marathon. We analyzed a database cont...Endurance running became a mass phenomenon throughout the 1980s around the world. Therefore, we wanted to investigate the participation and performance trends of runners in a half marathon. We analyzed a database containing the number of people who signed up and finished as well as age group, gender, placement, and runtime for all runners from a half marathon between 2003 and 2009. More than 35,000 runners participated in the half marathon, with an 80% increase in total participation during the 7 years analyzed. We verified that the annual participation increased, with a greater increase seen in female and middle-aged people of both genders, and runtimes of last finishers increased gradually in most of the age groups and both genders. However, while the number of people who signed up increased, there was a decrease in the number of participants who finished resulting in a negative correlation. This finding in association with the decrease in the percentage of finishers shows that each year the fitness deteriorated in both genders and across all ages.展开更多
The rehabilitation of older buildings for residential use that started in the last few decades of the 20th century has become recurrent in some Brazilian cities. In Sao Paulo, for instance, this subject is within the ...The rehabilitation of older buildings for residential use that started in the last few decades of the 20th century has become recurrent in some Brazilian cities. In Sao Paulo, for instance, this subject is within the context of the revitalization of its downtown area with the reintroduction of residential occupancy in the region as a consequence of actions taken by public and private groups. However, older buildings were designed based on the technologies and regulations available in the past and applied to meet the lifestyles of the time of their construction. This paper presents a method for the analysis of older apartment buildings, diagnosing their strengths and limitations in adapting to both the new Brazilian regulatory and legislative requirements, and the contemporary domestic demands. Requirements, criteria and methods for evaluation were studied, and defined as well as procedures for the application of a method which allows for a physical and systematic analysis of old apartment buildings. It was found that the proposed method can be an important support tool at the moment of studying the feasibility of rehabilitation processes, guiding and providing grounds for the design and building decisions of the professionals involved in these processes.展开更多
Introduction: Obesity has been considered a global epidemic and a serious public health problem closely related to other diseases. Moreover, obese individuals have limitations in physical capacity and pulmonary functi...Introduction: Obesity has been considered a global epidemic and a serious public health problem closely related to other diseases. Moreover, obese individuals have limitations in physical capacity and pulmonary function. Weight loss induced by bariatric surgery appears to help reverse this situation. However, questions about physical capacity and lung function, and its relationship with body composition remain to be clarified. Objective: To evaluate the physical capacity, body composition and lung function in women undergoing bariatric surgery. Methods: Twenty five women who underwent bariatric surgery between 6 and 24 months ago, and 10 non-obese women were evaluated for exercise capacity by the six minutes walk test (6 MWT), body composition by bio-electrical impedance analysis and lung function by spirometry and measurement of maximal static respiratory pressures. Results: Subjects with BMI 2 were found to have better physical performance, demonstrated by increased 6 MWT distance, not differing from non-obese women. When compared with non-obese women, there were no significant differences in body composition and lung function. Higher BMI was correlated with shorter distances in 6 MWT. Conclusion: 6 to 24 months after surgery, when the weight loss of patients who underwent bariatric surgery reaches levels considered non-obese, it provides improvement in physical performance to a level similar to that of non-obese patients.展开更多
Despite scientific advances in the Oncology field,cancer remains a leading cause of death worldwide.Molecular and cellular heterogeneity of head and neck squamous cell carcinoma(HNSCC)is a significant contributor to t...Despite scientific advances in the Oncology field,cancer remains a leading cause of death worldwide.Molecular and cellular heterogeneity of head and neck squamous cell carcinoma(HNSCC)is a significant contributor to the unpredictability of the clinical response and failure in cancer treatment.Cancer stem cells(CSCs)are recognized as a subpopulation of tumor cells that can drive and maintain tumorigenesis and metastasis,leading to poor prognosis in different types of cancer.CSCs exhibit a high level of plasticity,quickly adapting to the tumor microenvironment changes,and are intrinsically resistant to current chemo and radiotherapies.The mechanisms of CSC-mediated therapy resistance are not fully understood.However,they include different strategies used by CSCs to overcome challenges imposed by treatment,such as activation of DNA repair system,anti-apoptotic mechanisms,acquisition of quiescent state and Epithelial-mesenchymal transition,increased drug efflux capacity,hypoxic environment,protection by the CSC niche,overexpression of stemness related genes,and immune surveillance.Complete elimination of CSCs seems to be the main target for achieving tumor control and improving overall survival for cancer patients.This review will focus on the multi-factorial mechanisms by which CSCs are resistant to radiotherapy and chemotherapy in HNSCC,supporting the use of possible strategies to overcome therapy failure.展开更多
文摘The challenge of keeping and getting new customers drives the development of new practices to meet the consumption needs of increasingly tends to micro-segmentation of product and consumer market. The new consumption habits of brazilians brought new prospects for market. The objective of this paper is to develop of a dynamic vehicle routing system supported by the behavior of urban traffic in the city ofSao Paulo using Neuro Fuzzy Network. The methodology of this paper consists in the capture of relevant events that interfere with the flow of traffic of the city of Sao Paulo and implementation of a Fuzzy Neural Network trained with these events in order to foresee the traffic behavior. The system offers three labels of hierarchical routing, thus is possible to consider not only the basic factors of routing, but too external factors that directly influence on the flow of traffic and the disruption which may be avoided in large cities, through alternative routes （dynamic vehicle routing）. Predicting the behavior of traffic represents the strategic level routing, dynamic vehicle routing is the tactical level, and routing algorithms to the operational level. This paper will not be discussed the operational level.
文摘Neuroplasticity is a condition that is present from birth, being found in the central and peripheral nervous system, in both physiological and pathological terms. Based on the findings, therapeutic and non-therapeutic attempts were tested on spinal cord trauma to recover locomotor function below the level of the injury. The work defined and showed other forms of the term neuroplasticity, talk about some pathological and non-pathological conditions, and, finally, show neuroplasticity and some of its treatments in the spinal cord injury process. A narrative literature review from 2000 to 2020 of the PubMed platform was conducted and analysis of two books for the elaboration of this <span>work. Animal/human studies were included that addressed pathologies,</span> forms of treatment for spinal trauma, and qualis from B1 to A1. Pre-2000 articles, which addressed neuroplasticity only to understand the molecular mechanisms and articles that were not in English, were excluded. As a result, the main molecules and structures that inhibit neuroplasticity were found, and, based on their knowledge, forms of treatments were developed to inhibit these molecules and structures to assist in neuroplasticity and assist in possible functional recovery. It can be concluded that the physiological barriers are already being overcome by the most recent forms of treatment and that soon new studies may propose a form of treatment that is protocoled for all patients.
基金Supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil(CAPES),No.code 001São Paulo Research Foundation(FAPESP),No.2018/05571-0 and No.2018/05705-6.
文摘BACKGROUND Inflammatory bowel diseases(IBDs)are chronic diseases that demand continuous interaction between patients and healthcare providers.Quality of care(QoC)is a factor that contributes to a patient’s adherence to treatment and its success.AIM To evaluate QoC in patients from a single IBD reference center.METHODS This cross-sectional study included 133 patients from a single Brazilian IBD public health center.QoC was evaluated through the QoC Through the Eyes of Patients with IBD(QUOTE-IBD)questionnaire(based on patient perspectives),which measures eight dimensions of care.We compared QoC among patients with Crohn’s disease and ulcerative colitis and analyzed the clinical and psychological factors associated with QoC satisfaction.Clinical evaluations assessed disease characteristics,quality of life,anxiety,and depression levels.RESULTS Sixty-nine patients with Crohn’s disease and 64 with ulcerative colitis were interviewed.The mean age was 37.26 years±13.05 years,and 63.91%of the patients were women.The mean duration of the disease was 8.44 years±7.59 years,where most patients were in remission(70.31%of patients with ulcerative colitis and 62.32%with Crohn’s disease).The total QoC score of the sample was 8.61 years±1.31 points,indicating that the QoC provided by the center was unsatisfactory.According to univariate logistic regression,patients with Crohn’s disease had higher satisfaction rates than those with ulcerative colitis[odds ratio(OR):2.746;95%confidence interval(CI):1.360-5.541;P=0.0048]and patients on infliximab(OR:2.175;95%CI:1.037-4.562;P=0.0398).CONCLUSION Patients from the IBD public center reported good doctor-patient relationships,but had problems related to the healthcare structure.Evaluation of healthcare centers is of paramount to improve QoC for the patients involved.
文摘The objective of this study was characterizing the gelatin from the chicken feet by FTIR （Fourier transform infrared） spectroscopy. Two gelatin samples were prepared for the experiment which were extracted of 200 g of chicken feet by a thermal bath of 4% acetyl acid solution at 60 ℃. A commercial gelatin was used to compare the results. FTIR spectra of gelatin samples were recorded using a Nicolet iS5 FTIR spectrometer equipped with an ATR/iD3 with argon horizontal cell in which the spectra were varied in the range of 400-4,000 cm1 at 16 ~C. The results showed that FTIR spectra of the chicken feet gelatin had the most with the vibration peak at wave numbers of 1,652.01 cm~ to the amide I, of 1,539.87 cm1 to the amide II, of 1,241.29 cm~ to the amide III, of 2,923.72 cm-~ to the amide B and of 3,399.56 cm~ to the amide A. The collagen composition of the chicken feet gelatins was twotimes larger than the commercial gelatin and the vibration bands to beef gelatin have been different from chicken feet gelatins. This demonstrates that chicken feet gelatins are very good nutritional quality when compared to the commercial gelatin.
文摘The Web development has drastically changed the human interaction and communication, leading to an exponential growth of data generated by users in various digital media. This mass of data provides opportunities for understanding people’s opinions about products, services, processes, events, political movements, and organizational strategies. In this context, it becomes important for companies to be able to assess customer satisfaction about their products or services. One of the ways to evaluate customer sentiment is the use of Sentiment Analysis, also known as Opinion Mining. This research aims to compare the efficiency of an automatic classifier based on dictionary with the classification by human jurors in a set of comments made by customers in Portuguese language. The data consist of opinions of service users of one of the largest Brazilian online employment agencies. The performance evaluation of the classification models was done using Kappa index and a Confusion Matrix. As the main finding, it is noteworthy that the agreement between the classifier and the human jurors came to moderate, with better performance for the dictionary-based classifier. This result was considered satisfactory, considering that the Sentiment Analysis in Portuguese language is a complex task and demands more research and development.
文摘Objective: The aim of the study was to make a literature review on counseling and family education about the care with tracheostomy and develop a guidance booklet for parents about the cautions in handling tracheostomy tubes at home. Methods: This research is based on literature review from 1992 to 2012, realized from October of 2011 to August 2012, through the following databases: medline, lilacs, scielo and sibinet USP, with the elaboration of a guidance booklet for parents, about home care of tracheostomized children. Results: We elaborated a guidance booklet for parents, about the care of tracheostomized children and all were described according to literature review. Conclusion: According to the literature review family education in the care of tracheostomized children is essential so that caregivers have full autonomy to safely and effectively conduct the necessary techniques in their homes.
文摘Purpose: Children with liver impairment are likely to develop changes in autonomic nervous function and delay in motor development. The assessment and identification of these dysfunctions may allow an appropriate physiotherapeutic care. Method: Cross sectional study of 18 infants, 11 controls and 7 infants (post-liver transplantation) with an average age of 10 ± 4.5 months, was evaluated in pre- and post-liver transplant. All infants underwent to assessments of motor skills, body composition, chest and abdominal motion, and cardiac autonomic modulation was measured by heart rate variability. Results: Motor delay and malnutrition were found in all infants. The gravity index (PELD)—pediatric end-stage liver disease—showed a negative correlation with the Alberta Infant Motor Scale (r = 0.83, p = 0.01). In addition, reduced parasympathetic modulation was demonstrated by the rMSSD, SD1 and ApEn, pre- and post-transplant. Conclusion: Infants with liver disease, even after transplantation, have delay in motor development, as well as changes in their nutritional and autonomic dysfunction.
文摘The paper was monitored the conductivity （g.L＂l of NaCI）, the absorbances values （Abs） and the amount of TOC （total organic carbon）, before and after five consecutive dyeings made with reuse water, obtained from treated effluent by UV/H202 photocatalysis. All rates of decolorization were above 92%, the removal of total organic carbon was above 89% in all treatments and the economy of NaCI was from 3.10 in the first recipe, 3.17 in the second, 3.49 in the third, 3.79 in the fourth and 4.05 in the fifth recipe. The five dyeings compared with same dyeings made with deionized water presented a color deviation （AE＊） below 1. The conventional dyeings would consume 80 L/kg against 40 L/kg used in the dyeing process proposed in this study, representing a great economy of water, with no discharge of effluents.
文摘Endurance running became a mass phenomenon throughout the 1980s around the world. Therefore, we wanted to investigate the participation and performance trends of runners in a half marathon. We analyzed a database containing the number of people who signed up and finished as well as age group, gender, placement, and runtime for all runners from a half marathon between 2003 and 2009. More than 35,000 runners participated in the half marathon, with an 80% increase in total participation during the 7 years analyzed. We verified that the annual participation increased, with a greater increase seen in female and middle-aged people of both genders, and runtimes of last finishers increased gradually in most of the age groups and both genders. However, while the number of people who signed up increased, there was a decrease in the number of participants who finished resulting in a negative correlation. This finding in association with the decrease in the percentage of finishers shows that each year the fitness deteriorated in both genders and across all ages.
文摘The rehabilitation of older buildings for residential use that started in the last few decades of the 20th century has become recurrent in some Brazilian cities. In Sao Paulo, for instance, this subject is within the context of the revitalization of its downtown area with the reintroduction of residential occupancy in the region as a consequence of actions taken by public and private groups. However, older buildings were designed based on the technologies and regulations available in the past and applied to meet the lifestyles of the time of their construction. This paper presents a method for the analysis of older apartment buildings, diagnosing their strengths and limitations in adapting to both the new Brazilian regulatory and legislative requirements, and the contemporary domestic demands. Requirements, criteria and methods for evaluation were studied, and defined as well as procedures for the application of a method which allows for a physical and systematic analysis of old apartment buildings. It was found that the proposed method can be an important support tool at the moment of studying the feasibility of rehabilitation processes, guiding and providing grounds for the design and building decisions of the professionals involved in these processes.
文摘Introduction: Obesity has been considered a global epidemic and a serious public health problem closely related to other diseases. Moreover, obese individuals have limitations in physical capacity and pulmonary function. Weight loss induced by bariatric surgery appears to help reverse this situation. However, questions about physical capacity and lung function, and its relationship with body composition remain to be clarified. Objective: To evaluate the physical capacity, body composition and lung function in women undergoing bariatric surgery. Methods: Twenty five women who underwent bariatric surgery between 6 and 24 months ago, and 10 non-obese women were evaluated for exercise capacity by the six minutes walk test (6 MWT), body composition by bio-electrical impedance analysis and lung function by spirometry and measurement of maximal static respiratory pressures. Results: Subjects with BMI 2 were found to have better physical performance, demonstrated by increased 6 MWT distance, not differing from non-obese women. When compared with non-obese women, there were no significant differences in body composition and lung function. Higher BMI was correlated with shorter distances in 6 MWT. Conclusion: 6 to 24 months after surgery, when the weight loss of patients who underwent bariatric surgery reaches levels considered non-obese, it provides improvement in physical performance to a level similar to that of non-obese patients.
基金supported by Sao Paulo Research Foundation[FAPESP,grant number 2018/08540-8]Coordination for the Improvement of Higher Education Personnel,[CAPES,88882.376926/2019-01].
文摘Despite scientific advances in the Oncology field,cancer remains a leading cause of death worldwide.Molecular and cellular heterogeneity of head and neck squamous cell carcinoma(HNSCC)is a significant contributor to the unpredictability of the clinical response and failure in cancer treatment.Cancer stem cells(CSCs)are recognized as a subpopulation of tumor cells that can drive and maintain tumorigenesis and metastasis,leading to poor prognosis in different types of cancer.CSCs exhibit a high level of plasticity,quickly adapting to the tumor microenvironment changes,and are intrinsically resistant to current chemo and radiotherapies.The mechanisms of CSC-mediated therapy resistance are not fully understood.However,they include different strategies used by CSCs to overcome challenges imposed by treatment,such as activation of DNA repair system,anti-apoptotic mechanisms,acquisition of quiescent state and Epithelial-mesenchymal transition,increased drug efflux capacity,hypoxic environment,protection by the CSC niche,overexpression of stemness related genes,and immune surveillance.Complete elimination of CSCs seems to be the main target for achieving tumor control and improving overall survival for cancer patients.This review will focus on the multi-factorial mechanisms by which CSCs are resistant to radiotherapy and chemotherapy in HNSCC,supporting the use of possible strategies to overcome therapy failure.
