Chronic constipation is a common and extremely troublesome disorder that significantly reduces the quality of life,and this fact is consistent with the high rate at which health care is sought for this condition.The a...Chronic constipation is a common and extremely troublesome disorder that significantly reduces the quality of life,and this fact is consistent with the high rate at which health care is sought for this condition.The aim of this project was to develop a consensus for the diagnosis and treatment of chronic constipation and obstructed defecation.The commission presents its results in a "Question-Answer" format,including a set of graded recommendations based on a systematic review of the literature and evidence-based medicine.This section represents the consensus for the diagnosis.The history includes information relating to the onset and duration of symptoms and may reveal secondary causes of constipation.The presence of alarm symptoms and risk factors requires investigation.The physical examination should assess the presence of lesions in the anal and perianal region.The evidence does not support the routine use of blood testing and colonoscopy or barium enema for constipation.Various scoring systems are available to quantify the severity of constipation;the Constipation Severity Instrument for constipation and the obstructed defecation syndrome score for obstructed defecation are the most reliable.The Constipation-Related Quality of Life is an excellent tool for evaluating the patient's quality of life.No single test provides a pathophysiological basis for constipation.Colonic transit and anorectal manometry define the pathophysiologic subtypes.Balloon expulsion is a simple screening test for defecatory disorders,but it does not define the mechanisms.Defecography detects structural abnormalities and assesses functional parameters.Magnetic resonance imaging and/or pelvic floor sonography can further complement defecography by providing information on the movement of the pelvic floor and the organs that it supports.All these investigations are indicated to differentiate between slow transit constipation and obstructed defecation because the treatments differ between these conditions.展开更多
Because of its excellent dose distribution,proton therapy is becoming increasingly popular in the medical application of cancer treatment.A synchrotron-based proton therapy facility was designed and constructed in Sha...Because of its excellent dose distribution,proton therapy is becoming increasingly popular in the medical application of cancer treatment.A synchrotron-based proton therapy facility was designed and constructed in Shanghai.The synchrotron,beam delivery system,and other technical systems were commissioned and reached their expected performances.After a clinical trial of 47 patients was finished,the proton therapy facility obtained a registration certificate from the National Medical Products Administration.The characteristics of the accelerator and treatment systems are described in this article.展开更多
The effectiveness of monitoring and early-warning systems for ground deformation phenomena,such as sinkholes,depends on their ability to accurately resolve the ongoing ground displacement and detect the subtle deforma...The effectiveness of monitoring and early-warning systems for ground deformation phenomena,such as sinkholes,depends on their ability to accurately resolve the ongoing ground displacement and detect the subtle deformation preceding catastrophic failures.Sagging sinkholes with a slow subsidence rate and diffuse edges pose a significant challenge for subsidence monitoring due to the low deformation rates and limited lateral strain gradients.In this work,we satisfactorily illustrate the practicality of the Brillouin optical time domain analysis(BOTDA)to measure the spatial-temporal patterns of the vertical displacement in such challenging slow-moving sagging sinkholes.To assess the performance of the approach,we compare the strain recorded by the distributed optical fiber sensor with the vertical displacement measured by high-precision leveling.The results show a good spatial correlation with the ability to identify the maximum subsidence point.There is also a good temporal correlation with the detection of an acceleration phase in the subsidence associated with a flood event.展开更多
The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic syst...The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic system.Shijingshan District of Beijing City is taken as a research object.By analyzing and processing population distribution data,POI data,and shared bicycle data,the shortcomings and deficiencies of the current slow traffic system in Shijingshan District are explored,and corresponding solutions are proposed,in order to provide new ideas and methods for future urban planning from the perspective of data.展开更多
A simple,yet accurate modi?ed multi-scale method(MMSM)for an approximately analytical solution in nonlinear oscillators with two time scales under forced harmonic excitation is proposed.This method depends on the clas...A simple,yet accurate modi?ed multi-scale method(MMSM)for an approximately analytical solution in nonlinear oscillators with two time scales under forced harmonic excitation is proposed.This method depends on the classical multi-scale method(MSM)and the method of variation of parameters.Assuming that the forced excitation is a constant,one could easily obtain the approximate analytical solution of the simpli?ed system based on the traditional MSM.Then,this solution for the oscillator under forced harmonic excitation could be established after replacing the harmonic excitation by the constant excitation.To certify the correctness and precision of the proposed analytical method,the van der Pol system with two scales subject to slowly periodic excitation is investigated;this system presents rich dynamical phenomena such as spiking(SP),spiking-quiescence(SP-QS),and quiescence(QS)responses.The approximate analytical expressions of the three types of responses are given by the MMSM,and it can be found that the precision of the new analytical method is higher than that of the classical MSM and better than that of the harmonic balance method(HBM).The results obtained by the present method are considerably better than those obtained by traditional methods,quantitatively and qualitatively,particularly when the excitation frequency is far less than the natural frequency of the system.展开更多
基金Supported by Associazione Italiana Gastroenterologi and Endoscopisti Digestivi Ospedalieri via N Colajanni,4-00191 Roma,ItalySocietà Italiana di Chirurgia Colo-Rettale via Medici,23-10143Torino,Italy
文摘Chronic constipation is a common and extremely troublesome disorder that significantly reduces the quality of life,and this fact is consistent with the high rate at which health care is sought for this condition.The aim of this project was to develop a consensus for the diagnosis and treatment of chronic constipation and obstructed defecation.The commission presents its results in a "Question-Answer" format,including a set of graded recommendations based on a systematic review of the literature and evidence-based medicine.This section represents the consensus for the diagnosis.The history includes information relating to the onset and duration of symptoms and may reveal secondary causes of constipation.The presence of alarm symptoms and risk factors requires investigation.The physical examination should assess the presence of lesions in the anal and perianal region.The evidence does not support the routine use of blood testing and colonoscopy or barium enema for constipation.Various scoring systems are available to quantify the severity of constipation;the Constipation Severity Instrument for constipation and the obstructed defecation syndrome score for obstructed defecation are the most reliable.The Constipation-Related Quality of Life is an excellent tool for evaluating the patient's quality of life.No single test provides a pathophysiological basis for constipation.Colonic transit and anorectal manometry define the pathophysiologic subtypes.Balloon expulsion is a simple screening test for defecatory disorders,but it does not define the mechanisms.Defecography detects structural abnormalities and assesses functional parameters.Magnetic resonance imaging and/or pelvic floor sonography can further complement defecography by providing information on the movement of the pelvic floor and the organs that it supports.All these investigations are indicated to differentiate between slow transit constipation and obstructed defecation because the treatments differ between these conditions.
文摘Because of its excellent dose distribution,proton therapy is becoming increasingly popular in the medical application of cancer treatment.A synchrotron-based proton therapy facility was designed and constructed in Shanghai.The synchrotron,beam delivery system,and other technical systems were commissioned and reached their expected performances.After a clinical trial of 47 patients was finished,the proton therapy facility obtained a registration certificate from the National Medical Products Administration.The characteristics of the accelerator and treatment systems are described in this article.
基金This work has been supported by Ministerio de Ciencia e Innovacion,Gobierno de Espana(Grant Nos.CGL2017-85045-P,PID2021-123189NB-I00,DI-17-09169)Government of Aragon(Grant No.Reference Group T20_23R)Jorge Sevil has a predoctoral contract(Grant No.PRE2018-084240)co-financed by the Spanish Government and the European Social Fund(ESF).
文摘The effectiveness of monitoring and early-warning systems for ground deformation phenomena,such as sinkholes,depends on their ability to accurately resolve the ongoing ground displacement and detect the subtle deformation preceding catastrophic failures.Sagging sinkholes with a slow subsidence rate and diffuse edges pose a significant challenge for subsidence monitoring due to the low deformation rates and limited lateral strain gradients.In this work,we satisfactorily illustrate the practicality of the Brillouin optical time domain analysis(BOTDA)to measure the spatial-temporal patterns of the vertical displacement in such challenging slow-moving sagging sinkholes.To assess the performance of the approach,we compare the strain recorded by the distributed optical fiber sensor with the vertical displacement measured by high-precision leveling.The results show a good spatial correlation with the ability to identify the maximum subsidence point.There is also a good temporal correlation with the detection of an acceleration phase in the subsidence associated with a flood event.
基金Sponsored by Beijing Natural Science Foundation General Project(8212009)Construction of Philosophy and Social Sciences Base in Beijing-Research on Beijing Urban Renewal and Comprehensive Management of Old Community En-vironment2023 Education Reform Project of North China University of Technology(108051360023XN264-25).
文摘The slow traffic system is an important component of urban transportation,and the prerequisite and necessary condition for Beijing to continue promoting“green priority”are establishing a good urban slow traffic system.Shijingshan District of Beijing City is taken as a research object.By analyzing and processing population distribution data,POI data,and shared bicycle data,the shortcomings and deficiencies of the current slow traffic system in Shijingshan District are explored,and corresponding solutions are proposed,in order to provide new ideas and methods for future urban planning from the perspective of data.
基金the National Natural Science Foundation of China(Nos.11672191,11772206,and U1934201)the Hundred Excellent Innovative Talents Support Program in Hebei University(No.SLRC2017053)。
文摘A simple,yet accurate modi?ed multi-scale method(MMSM)for an approximately analytical solution in nonlinear oscillators with two time scales under forced harmonic excitation is proposed.This method depends on the classical multi-scale method(MSM)and the method of variation of parameters.Assuming that the forced excitation is a constant,one could easily obtain the approximate analytical solution of the simpli?ed system based on the traditional MSM.Then,this solution for the oscillator under forced harmonic excitation could be established after replacing the harmonic excitation by the constant excitation.To certify the correctness and precision of the proposed analytical method,the van der Pol system with two scales subject to slowly periodic excitation is investigated;this system presents rich dynamical phenomena such as spiking(SP),spiking-quiescence(SP-QS),and quiescence(QS)responses.The approximate analytical expressions of the three types of responses are given by the MMSM,and it can be found that the precision of the new analytical method is higher than that of the classical MSM and better than that of the harmonic balance method(HBM).The results obtained by the present method are considerably better than those obtained by traditional methods,quantitatively and qualitatively,particularly when the excitation frequency is far less than the natural frequency of the system.
