BACKGROUND Paravalvular leak(PVL),also known as paravalvular prosthetic regurgitation,is not a rare complication after surgical valve replacement,and it may cause varying degrees of heart failure.The transcatheter clo...BACKGROUND Paravalvular leak(PVL),also known as paravalvular prosthetic regurgitation,is not a rare complication after surgical valve replacement,and it may cause varying degrees of heart failure.The transcatheter closure of PVL is technically demanding and challenging.CASE SUMMARY A 68-year-old man presented with degenerative mitral regurgitation with heart failure,New York Heart Association functional class 3.He received bioprosthetic mitral valve replacement in December 2019.PVL was noted at the location of the aorto-mitral curtain in transesophageal echocardiography without signs of endocarditis or dehiscence of the bioprosthetic valve.Transseptal transcatheter closure of the mitral PVL was performed efficiently using the EchoNavigator virtual marker and Agilis NxT steerable introducer.CONCLUSION This case highlights that the EchoNavigator virtual marker and Agilis NxT steerable introducer can facilitate transseptal transcatheter closure of mitral PVL by reducing the procedure time and contrast media.展开更多
Background: Turner syndrome (TS) affects approximately one in 2500 live births in females. Scoliosis is one of the skeletal manifestations of TS, but most cases only require observation or conservative treatment. We e...Background: Turner syndrome (TS) affects approximately one in 2500 live births in females. Scoliosis is one of the skeletal manifestations of TS, but most cases only require observation or conservative treatment. We experienced two adolescent TS cases in which progression of scoliosis required surgical intervention, which is very rare in TS. Case Presentation: Case 1: An 11-year-old female with TS had a single thoracic curve that rapidly progressed to a triple major curve with a 76˚ main thoracic curve at age 13.5 years. Case 2: A 14-year-old female with TS had a 59˚ single thoracic curve. In both cases, growth hormone and estrogen replacement therapy were administered preoperatively and planned postoperatively. Posterior correction and instrumented fusion using simultaneous translation on two rods technique and direct vertebral rotation with the use of multiple rod introducers were successfully performed in both cases. No crankshaft phenomenon or distal adding on were observed during those postoperative courses. Conclusions: Although curve pattern of the deformity is similar to adolescent idiopathic scoliosis (AIS), bone quality in patient with TS is lower. In the context of surgical interventions for scoliosis associated with TS, it is imperative to employ surgical techniques that take into account the suboptimal bone quality. If continuation of hormone replacement therapy is planned after corrective surgery for scoliosis in TS patients, it is essential to follow the patient closely postoperatively until bone maturation is complete.展开更多
1 People often think of musical memories as fixed images of the past,but a recent study suggests music may do more than just activate memories-it might even change how you remember them.2 The hypothesis(假说)was roote...1 People often think of musical memories as fixed images of the past,but a recent study suggests music may do more than just activate memories-it might even change how you remember them.2 The hypothesis(假说)was rooted in the idea that when you recall a memory,it becomes temporarily flexible,allowing new information to be integrated.To prove it,the researchers developed a three⁃day experiment to test whether music played during recall might introduce new emotional elements into the original memory.展开更多
Electrocatalytic reduction of NO(NORR) is an effective method for NH_(3) synthesis, due to low bonding energy of N–O bond. In this work, we have investigated many CrS_(2)based catalysts, including pristine CrS_(2),Cr...Electrocatalytic reduction of NO(NORR) is an effective method for NH_(3) synthesis, due to low bonding energy of N–O bond. In this work, we have investigated many CrS_(2)based catalysts, including pristine CrS_(2),CrS_(2)with one S vacancy(v-CrS_(2)), and Ti doped CrS_(2)(Ti@CrS_(2)). The results have shown that the pristine CrS_(2)exhibits inert character for NO activation. However, v-CrS_(2)and Ti@CrS_(2)can exhibit enhanced interaction with NO, due to increased charge transfer between NO and substrates(0.52–0.75 e) and enhanced adsorption energies of NO on the catalysts(-0.96~-1.64 e V), compared to the situation of CrS_(2)(0.065 e/-0.30 e V). From the free energy profiles of NO electro-reduction to NH3, we can see that the v-CrS_(2)and Ti@CrS_(2)all exhibit ultralow limiting potentials of-0.03~-0.47 V, following both*NOH and*NHO mechanisms. Therefore, introducing vacancy and doping are all promising modification strategies for NORR catalysts. The results have provided a new idea for the search of catalysts for efficient electrocatalytic reduction of NO.展开更多
Molecular recognition of bioreceptors and enzymes relies on orthogonal interactions with small molecules within their cavity. To date, Chinese scientists have developed three types of strategies for introducing active...Molecular recognition of bioreceptors and enzymes relies on orthogonal interactions with small molecules within their cavity. To date, Chinese scientists have developed three types of strategies for introducing active sites inside the cavity of macrocyclic arenes to better mimic molecular recognition of bioreceptors and enzymes.The editorial aims to enlighten scientists in this field when they develop novel macrocycles for molecular recognition, supramolecular assembly, and applications.展开更多
Extreme droughts are anticipated to have detrimental impacts on forest ecosystems,especially in water-limited regions,due to the influence of climate change.However,considerable uncertainty remains regarding the patte...Extreme droughts are anticipated to have detrimental impacts on forest ecosystems,especially in water-limited regions,due to the influence of climate change.However,considerable uncertainty remains regarding the patterns in species-specific responses to extreme droughts.Here,we conducted a study integrating dendrochronology and remote sensing methods to investigate the mosaic-distributed maple-oak(native)natural forests and poplar plantations(introduced)in the Horqin Sandy Land,Northeast China.We assessed the impacts of extreme droughts on tree performances by measuring interannual variations in radial growth and vegetation index.The results showed that precipitation and self-calibrated palmer drought severity index(scPDSI)are the major factors influencing tree-ring width index(RWI)and normalized difference vegetation index(NDVI).The severe droughts between 2000 and 2004 resulted in reduced RWI in the three studied tree species as well as led to NDVI reductions in both the maple-oak natural forests and the poplar plantations.The RWI reached the nadir during the2000-2004 severe droughts and remained at low levels two years after the severe drought,creating a legacy effect.In contrast to the lack of significant correlation between RWI and scPDSI,NDVI exhibited a significant positive correlation with scPDSI indicating the greater sensitivity of canopy performance to droughts than radial growth.Furthermore,interspecific differences in RWI and NDVI responses were observed,with the fast-growing poplar species experiencing a more significant RWI decrease and more negative NDVI anomaly during severe droughts than native species,highlighting the species-specific trade-offs between drought resilience and growth rate.This study emphasizes the importance of combining tree-level radial growth with landscape-scale canopy remote sensing to understand forest resilience and response.Our study improves our understanding of forest responses to extreme drought and highlights species differences in climate responses,offering crucial insights for optimizing species selection in sustainable afforestation and forest management in water-limited regions under the influence of climate change.展开更多
Dear Editor, This letter deals with the problem of algorithm recommendation for online fault detection of spacecraft. By transforming the time series data into distributions and introducing a distribution-aware measur...Dear Editor, This letter deals with the problem of algorithm recommendation for online fault detection of spacecraft. By transforming the time series data into distributions and introducing a distribution-aware measure, a principal method is designed for quantifying the detectabilities of fault detection algorithms over special datasets.展开更多
This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in...This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup>) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p < 0.05) influenced grain yield production. Mean grain yields and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup> plots exhibiting the lowest and highest grain yields of 1238 kg∙ha<sup>−</sup><sup>1</sup> and 2098 kg∙ha<sup>−</sup><sup>1</sup>, respectively. Variety and nitrogen effects on partial factor productivity (PFP<sub>N</sub>), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p < 0.05) by these factors. The highest PFP<sub>N</sub> (41.3 kg grain kg<sup>−</sup><sup>1</sup>∙N) and AEN (29.4 kg grain kg<sup>−</sup><sup>1</sup>∙N) were obtained in the 30 kg∙N∙ha<sup>−</sup><sup>1</sup> plots, while the highest VCR (2.8) and MR (SLL 1.8 SLL<sup>−</sup><sup>1</sup> spent on N) were obtained in the 180 kg∙N∙ha<sup>−</sup><sup>1</sup>. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fertilization and improved farming practices that could be exploited for increased productivity of maize.展开更多
The application effect of 30 introduced flowering shrubs in landscape in Hefei City was comprehensively evaluated by the analytic hierarchy process(APH).A comprehensive evaluation model was established by using factor...The application effect of 30 introduced flowering shrubs in landscape in Hefei City was comprehensively evaluated by the analytic hierarchy process(APH).A comprehensive evaluation model was established by using factors such as plant type,resistance and drought tolerance of introduced flowering shrubs.The results show that the application effect of grade-I introduced flowering shrubs(including 12 kinds,e.g.Lantanacamara)was the best(j≥2.6),and that of grade-II introduced flowering shrubs(including 14 kinds,e.g.Abelia×grandiflora‘Francis Mason’)was better(2.2≤j<2.6),while that of grade-III introduced flowering shrubs(including 4 kinds,e.g.Ligustrum×vicaryi)was moderate(j<2.2).The evaluation results can provide reference for the application effect of introduced flowering shrubs in landscape in Hefei City.展开更多
The pagination of this article online has been updated to pages 597-608 to match the print version.The Publisher sincerely apologizes for introducing this error online.
I recently got the opportunity to visit China to attend a seminar organized by the China Counsel for the Promotion of International Trade(CCPIT),for participants from the Belt and Road Initiative(BRI)countries.The pur...I recently got the opportunity to visit China to attend a seminar organized by the China Counsel for the Promotion of International Trade(CCPIT),for participants from the Belt and Road Initiative(BRI)countries.The purpose of the seminar was to invite the delegates from BRI countries,and give them firsthand experience of the Chinese development miracle by introducing them to Chinese history,its governance methodology and how it has managed to carry out its significant progress in the last three decades,for example,by following policies that facilitated entrepreneurship,and providing businesses the right kind of platform.展开更多
As an enthusiast of travelling,a young French entrepreneur has dedicated her life to sharing the vitality of China’s eastern economic hub with more people.ON the streets of Shanghai,China’s eastern mega city,you can...As an enthusiast of travelling,a young French entrepreneur has dedicated her life to sharing the vitality of China’s eastern economic hub with more people.ON the streets of Shanghai,China’s eastern mega city,you can often see a young French woman leading a group of tourists around the city on citywalks,introducing the history and culture of the metropolis to them in Chinese,English,and French.展开更多
During the annual meeting of the National People’s Congress(NPC),China’s top legislature,in March,President Xi Jinping stressed focusing on high-quality development as the top priority and developing new quality pro...During the annual meeting of the National People’s Congress(NPC),China’s top legislature,in March,President Xi Jinping stressed focusing on high-quality development as the top priority and developing new quality productive forces according to local conditions while deliberating with lawmakers from Jiangsu Province.Following the path that President Xi Jinping emphasized,SAIC-GM-Wuling Automobile Co.,Ltd.has been committed to modernizing research and development(R&D),introducing intelligent manufacturing,upgrading the automobile industry.展开更多
Aerodigestive cancer, like esophageal cancer or head and neck cancer, is well known to have a poor prognosis. It is often diagnosed in the late stages, with dysphagia being the major symptom. Insufficient nutrition an...Aerodigestive cancer, like esophageal cancer or head and neck cancer, is well known to have a poor prognosis. It is often diagnosed in the late stages, with dysphagia being the major symptom. Insufficient nutrition and lack of stimulation of the intestinal mucosa may worsen immune compromise due to toxic side effects. A poor nutritional status is a significant prognostic factor for increased mortality. Therefore, it is most important to optimize enteral nutrition in patients with aerodigestive cancer before and during treatment, as well as during palliative treatment. Percutaneous endoscopic gastrostomy(PEG) may be useful for nutritional support. However, PEG tube placement is limited by digestive tract stenosis and is an invasive endoscopic procedure with a risk of complications. There are three PEG techniques. The pull/push and introducer methods have been established as standard techniques for PEG tube placement. The modified introducer method, namely the direct method, allows for direct placement of a larger button-bumper-type catheter device. PEG tube placement using the introducer method or the direct method may be a much safer alternative than the pull/push method. PEG may be recommended in patients with aerodigestive cancer because of the improved complication rate.展开更多
文摘BACKGROUND Paravalvular leak(PVL),also known as paravalvular prosthetic regurgitation,is not a rare complication after surgical valve replacement,and it may cause varying degrees of heart failure.The transcatheter closure of PVL is technically demanding and challenging.CASE SUMMARY A 68-year-old man presented with degenerative mitral regurgitation with heart failure,New York Heart Association functional class 3.He received bioprosthetic mitral valve replacement in December 2019.PVL was noted at the location of the aorto-mitral curtain in transesophageal echocardiography without signs of endocarditis or dehiscence of the bioprosthetic valve.Transseptal transcatheter closure of the mitral PVL was performed efficiently using the EchoNavigator virtual marker and Agilis NxT steerable introducer.CONCLUSION This case highlights that the EchoNavigator virtual marker and Agilis NxT steerable introducer can facilitate transseptal transcatheter closure of mitral PVL by reducing the procedure time and contrast media.
文摘Background: Turner syndrome (TS) affects approximately one in 2500 live births in females. Scoliosis is one of the skeletal manifestations of TS, but most cases only require observation or conservative treatment. We experienced two adolescent TS cases in which progression of scoliosis required surgical intervention, which is very rare in TS. Case Presentation: Case 1: An 11-year-old female with TS had a single thoracic curve that rapidly progressed to a triple major curve with a 76˚ main thoracic curve at age 13.5 years. Case 2: A 14-year-old female with TS had a 59˚ single thoracic curve. In both cases, growth hormone and estrogen replacement therapy were administered preoperatively and planned postoperatively. Posterior correction and instrumented fusion using simultaneous translation on two rods technique and direct vertebral rotation with the use of multiple rod introducers were successfully performed in both cases. No crankshaft phenomenon or distal adding on were observed during those postoperative courses. Conclusions: Although curve pattern of the deformity is similar to adolescent idiopathic scoliosis (AIS), bone quality in patient with TS is lower. In the context of surgical interventions for scoliosis associated with TS, it is imperative to employ surgical techniques that take into account the suboptimal bone quality. If continuation of hormone replacement therapy is planned after corrective surgery for scoliosis in TS patients, it is essential to follow the patient closely postoperatively until bone maturation is complete.
文摘1 People often think of musical memories as fixed images of the past,but a recent study suggests music may do more than just activate memories-it might even change how you remember them.2 The hypothesis(假说)was rooted in the idea that when you recall a memory,it becomes temporarily flexible,allowing new information to be integrated.To prove it,the researchers developed a three⁃day experiment to test whether music played during recall might introduce new emotional elements into the original memory.
基金funded by the Natural Science Foundation of China (No. 21603109)the Henan Joint Fund of the National Natural Science Foundation of China (No. U1404216)+1 种基金the Scientific Research Program Funded by Shaanxi Provincial Education Department (No. 20JK0676)supported by Natural Science Basic Research Program of Shanxi (Nos. 2022JQ-108, 2022JQ096)。
文摘Electrocatalytic reduction of NO(NORR) is an effective method for NH_(3) synthesis, due to low bonding energy of N–O bond. In this work, we have investigated many CrS_(2)based catalysts, including pristine CrS_(2),CrS_(2)with one S vacancy(v-CrS_(2)), and Ti doped CrS_(2)(Ti@CrS_(2)). The results have shown that the pristine CrS_(2)exhibits inert character for NO activation. However, v-CrS_(2)and Ti@CrS_(2)can exhibit enhanced interaction with NO, due to increased charge transfer between NO and substrates(0.52–0.75 e) and enhanced adsorption energies of NO on the catalysts(-0.96~-1.64 e V), compared to the situation of CrS_(2)(0.065 e/-0.30 e V). From the free energy profiles of NO electro-reduction to NH3, we can see that the v-CrS_(2)and Ti@CrS_(2)all exhibit ultralow limiting potentials of-0.03~-0.47 V, following both*NOH and*NHO mechanisms. Therefore, introducing vacancy and doping are all promising modification strategies for NORR catalysts. The results have provided a new idea for the search of catalysts for efficient electrocatalytic reduction of NO.
文摘Molecular recognition of bioreceptors and enzymes relies on orthogonal interactions with small molecules within their cavity. To date, Chinese scientists have developed three types of strategies for introducing active sites inside the cavity of macrocyclic arenes to better mimic molecular recognition of bioreceptors and enzymes.The editorial aims to enlighten scientists in this field when they develop novel macrocycles for molecular recognition, supramolecular assembly, and applications.
基金supported by the National Natural Science Foundation of China(Nos.32220103010,32192431,31722013)the National Key R&D Program of China(Nos.2023YFF1304201,2020YFA0608100)+1 种基金the Major Program of Institute of Applied EcologyChinese Academy of Sciences(No.IAEMP202201)。
文摘Extreme droughts are anticipated to have detrimental impacts on forest ecosystems,especially in water-limited regions,due to the influence of climate change.However,considerable uncertainty remains regarding the patterns in species-specific responses to extreme droughts.Here,we conducted a study integrating dendrochronology and remote sensing methods to investigate the mosaic-distributed maple-oak(native)natural forests and poplar plantations(introduced)in the Horqin Sandy Land,Northeast China.We assessed the impacts of extreme droughts on tree performances by measuring interannual variations in radial growth and vegetation index.The results showed that precipitation and self-calibrated palmer drought severity index(scPDSI)are the major factors influencing tree-ring width index(RWI)and normalized difference vegetation index(NDVI).The severe droughts between 2000 and 2004 resulted in reduced RWI in the three studied tree species as well as led to NDVI reductions in both the maple-oak natural forests and the poplar plantations.The RWI reached the nadir during the2000-2004 severe droughts and remained at low levels two years after the severe drought,creating a legacy effect.In contrast to the lack of significant correlation between RWI and scPDSI,NDVI exhibited a significant positive correlation with scPDSI indicating the greater sensitivity of canopy performance to droughts than radial growth.Furthermore,interspecific differences in RWI and NDVI responses were observed,with the fast-growing poplar species experiencing a more significant RWI decrease and more negative NDVI anomaly during severe droughts than native species,highlighting the species-specific trade-offs between drought resilience and growth rate.This study emphasizes the importance of combining tree-level radial growth with landscape-scale canopy remote sensing to understand forest resilience and response.Our study improves our understanding of forest responses to extreme drought and highlights species differences in climate responses,offering crucial insights for optimizing species selection in sustainable afforestation and forest management in water-limited regions under the influence of climate change.
基金supported by the National Key R&D Program of China (2021YFB1715000)the National Natural Science Foundation of China (U1811461, 62022013, 12150007, 62103450, 61832003, 62272137)。
文摘Dear Editor, This letter deals with the problem of algorithm recommendation for online fault detection of spacecraft. By transforming the time series data into distributions and introducing a distribution-aware measure, a principal method is designed for quantifying the detectabilities of fault detection algorithms over special datasets.
文摘This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup>) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p < 0.05) influenced grain yield production. Mean grain yields and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup> plots exhibiting the lowest and highest grain yields of 1238 kg∙ha<sup>−</sup><sup>1</sup> and 2098 kg∙ha<sup>−</sup><sup>1</sup>, respectively. Variety and nitrogen effects on partial factor productivity (PFP<sub>N</sub>), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p < 0.05) by these factors. The highest PFP<sub>N</sub> (41.3 kg grain kg<sup>−</sup><sup>1</sup>∙N) and AEN (29.4 kg grain kg<sup>−</sup><sup>1</sup>∙N) were obtained in the 30 kg∙N∙ha<sup>−</sup><sup>1</sup> plots, while the highest VCR (2.8) and MR (SLL 1.8 SLL<sup>−</sup><sup>1</sup> spent on N) were obtained in the 180 kg∙N∙ha<sup>−</sup><sup>1</sup>. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fertilization and improved farming practices that could be exploited for increased productivity of maize.
基金Sponsored by the Innovation and Entrepreneurship Training Planning Project for University Students in Anhui Province(S202212216129)Key Research Project of Natural Science in Universities of Anhui Province(2023AH051816)General Teaching Research Project of Anhui Province(2022jyxm665).
文摘The application effect of 30 introduced flowering shrubs in landscape in Hefei City was comprehensively evaluated by the analytic hierarchy process(APH).A comprehensive evaluation model was established by using factors such as plant type,resistance and drought tolerance of introduced flowering shrubs.The results show that the application effect of grade-I introduced flowering shrubs(including 12 kinds,e.g.Lantanacamara)was the best(j≥2.6),and that of grade-II introduced flowering shrubs(including 14 kinds,e.g.Abelia×grandiflora‘Francis Mason’)was better(2.2≤j<2.6),while that of grade-III introduced flowering shrubs(including 4 kinds,e.g.Ligustrum×vicaryi)was moderate(j<2.2).The evaluation results can provide reference for the application effect of introduced flowering shrubs in landscape in Hefei City.
文摘The pagination of this article online has been updated to pages 597-608 to match the print version.The Publisher sincerely apologizes for introducing this error online.
文摘I recently got the opportunity to visit China to attend a seminar organized by the China Counsel for the Promotion of International Trade(CCPIT),for participants from the Belt and Road Initiative(BRI)countries.The purpose of the seminar was to invite the delegates from BRI countries,and give them firsthand experience of the Chinese development miracle by introducing them to Chinese history,its governance methodology and how it has managed to carry out its significant progress in the last three decades,for example,by following policies that facilitated entrepreneurship,and providing businesses the right kind of platform.
文摘As an enthusiast of travelling,a young French entrepreneur has dedicated her life to sharing the vitality of China’s eastern economic hub with more people.ON the streets of Shanghai,China’s eastern mega city,you can often see a young French woman leading a group of tourists around the city on citywalks,introducing the history and culture of the metropolis to them in Chinese,English,and French.
文摘During the annual meeting of the National People’s Congress(NPC),China’s top legislature,in March,President Xi Jinping stressed focusing on high-quality development as the top priority and developing new quality productive forces according to local conditions while deliberating with lawmakers from Jiangsu Province.Following the path that President Xi Jinping emphasized,SAIC-GM-Wuling Automobile Co.,Ltd.has been committed to modernizing research and development(R&D),introducing intelligent manufacturing,upgrading the automobile industry.
文摘Aerodigestive cancer, like esophageal cancer or head and neck cancer, is well known to have a poor prognosis. It is often diagnosed in the late stages, with dysphagia being the major symptom. Insufficient nutrition and lack of stimulation of the intestinal mucosa may worsen immune compromise due to toxic side effects. A poor nutritional status is a significant prognostic factor for increased mortality. Therefore, it is most important to optimize enteral nutrition in patients with aerodigestive cancer before and during treatment, as well as during palliative treatment. Percutaneous endoscopic gastrostomy(PEG) may be useful for nutritional support. However, PEG tube placement is limited by digestive tract stenosis and is an invasive endoscopic procedure with a risk of complications. There are three PEG techniques. The pull/push and introducer methods have been established as standard techniques for PEG tube placement. The modified introducer method, namely the direct method, allows for direct placement of a larger button-bumper-type catheter device. PEG tube placement using the introducer method or the direct method may be a much safer alternative than the pull/push method. PEG may be recommended in patients with aerodigestive cancer because of the improved complication rate.
