Context/objectives: The fight against Chronic Non-Communicable Diseases (NCDs) is a long-term undertaking, which requires available, motivated and well-managed human resources (HR). The administrative management of sk...Context/objectives: The fight against Chronic Non-Communicable Diseases (NCDs) is a long-term undertaking, which requires available, motivated and well-managed human resources (HR). The administrative management of skills on both qualitative and quantitative levels is one of the essential functions of a health system. To better implement policies of fight against High Blood Pressure (HBP) and other chronic diseases, it is important to establish strategies to retain health personnel. This loyalty requires favorable working conditions and consideration of the contribution-reward couple. Good working conditions are likely to reduce the phenomenon of medical nomadism;conversely, poor HR management can contribute to their exodus towards exotic “green pastures”, thus leading to an additional crisis in the Cameroonian health system. The fight against HBP is a complex, multifaceted and multifactorial reality that requires appropriate management model for all types of resources mainly HR. The main objective of this research is to show the impact of poor management of human resources in Cameroon health system on medical nomadism and the ineffectiveness of the fight against High Blood Pressure. Method: A cross-sectional descriptive survey among five hundred (500) health facilities in the center region of Cameroon has been conducted. A stratified probabilistic technique has been used, and the number of health facilities to be surveyed has been determined using the “sample size estimation table” of Depelteau. The physical questionnaires have been printed and then distributed to data collectors. After data collection, the latter were grouped during processing in Excel sheets. The Chi-square test was used for data with a qualitative value and that of Kolmogorov-Sminorf for data with a quantitative value to assess the normality and reliability of data. The Crochach’s Alpha reliability test allowed us to have a summary of the means and variances and then to search for intragroup correlations between variables. Descriptive analysis was possible with the XLSTAT 2016 software. Results: 43.60% of Health Facilities (HF) managers were unqualified. 82.20% of HF managers have staff in a situation of professional insecurity. They are mainly contractual (49.00), decision-making agents (24.40%), casual agents (08.80). The proportion of unstable personnel is average of 22.00% and very unstable, 12.00%.展开更多
BACKGROUND Gastroesophageal reflux is associated with poorer outcomes after lung transplant,likely through recurrent aspiration and allograft injury.Although prior studies have demonstrated a relationship between impe...BACKGROUND Gastroesophageal reflux is associated with poorer outcomes after lung transplant,likely through recurrent aspiration and allograft injury.Although prior studies have demonstrated a relationship between impedance-pH results and transplant outcomes,the role of esophageal manometry in the assessment of lung transplant patients remains debated,and the impact of esophageal dysmotility on transplant outcomes is unclear.Of particular interest is ineffective esophageal motility(IEM)and its associated impact on esophageal clearance.AIM To assess the relationship between pre-transplant IEM diagnosis and acute rejection after lung transplantation.METHODS This was a retrospective cohort study of lung transplant recipients at a tertiary care center between 2007 and 2018.Patients with pre-transplant anti-reflux surgery were excluded.Manometric and reflux diagnoses were recorded from pre-transplant esophageal function testing.Time-to-event analysis using Cox proportional hazards model was applied to evaluate outcome of first episode of acute cellular rejection,defined histologically per International Society of Heart and Lung Transplantation guidelines.Subjects not meeting this endpoint were censored at time of post-transplant anti-reflux surgery,last clinic visit,or death.Fisher’s exact test for binary variables and student’s t-test for continuous variables were performed to assess for differences between groups.RESULTS Of 184 subjects(54%men,mean age:58,follow-up:443 person-years)met criteria for inclusion.Interstitial pulmonary fibrosis represented the predominant pulmonary diagnosis(41%).During the follow-up period,60 subjects(33.5%)developed acute rejection.The all-cause mortality was 16.3%.Time-to-event univariate analyses demonstrated significant association between IEM and acute rejection[hazard ratio(HR):1.984,95%CI:1.03-3.30,P=0.04],confirmed on Kaplan-Meier curve.On multivariable analysis,IEM remained independently associated with acute rejection,even after controlling for potential confounders such as the presence of acid and nonacid reflux(HR:2.20,95%CI:1.18-4.11,P=0.01).Nonacid reflux was also independently associated with acute rejection on both univariate(HR:2.16,95%CI:1.26-3.72,P=0.005)and multivariable analyses(HR:2.10,95%CI:1.21-3.64,P=0.009),adjusting for the presence of IEM.CONCLUSION Pre-transplant IEM was associated with acute rejection after transplantation,even after controlling for acid and nonacid reflux.Esophageal motility testing may be considered in lung transplant to predict outcomes.展开更多
AIM: TO evaluate the association between IEM and gastropharyngeal reflux disease (GPRD) in patients who underwent ambulatory 24-h dual-probe pH monitoring for the evaluation of supraesophageal symptoms. METHODS: A...AIM: TO evaluate the association between IEM and gastropharyngeal reflux disease (GPRD) in patients who underwent ambulatory 24-h dual-probe pH monitoring for the evaluation of supraesophageal symptoms. METHODS: A total of 632 patients who underwent endoscopy, esophageal manometry and ambulatory 24-h dual-pH monitoring due to supraesophageal symptoms (e.g. globus, hoarseness, or cough) were enrolled. Of them, we selected the patients who had normal esophageal motility and IEM. The endoscopy and ambulatory pH monitoring findings were compared between the two groups. RESULTS;: A total of 264 patients with normal esophageal motility and 195 patients with the diagnosis of IEM were included in this study. There was no difference in the frequency of reflux esophagitis and hiatal hernia between the two groups. All the variables showing gastroesophageal reflux and gastropharyngeal reflux were not different between the two groups. The frequency of GERD and GPRD, as defined by ambulatory pH monitoring, was not different between the two groups. CONCLUSION: There was no association between IEM and GPRD as well as between IEM and GERD. IEM alone cannot be considered as a definitive marker for reflux disease.展开更多
AIM:To compare the demographic and clinical features of different manometric subsets of ineffective oesophageal motility(IOM;defined as ≥ 30% wet swallows with distal contractile amplitude < 30 mmHg) ,and to deter...AIM:To compare the demographic and clinical features of different manometric subsets of ineffective oesophageal motility(IOM;defined as ≥ 30% wet swallows with distal contractile amplitude < 30 mmHg) ,and to determine whether the prevalence of gastro-oesophageal reflux differs between IOM subsets. METHODS:Clinical characteristics of manometric subsets were determined in 100 IOM patients(73 female,median age 58 years) and compared to those of 100 age-and gender-matched patient controls with oesophageal symptoms,but normal manometry. Supine oesophageal manometry was performed with an eight-channel DentSleeve water-perfused catheter,and an ambulatory pH study assessed gastro-oesophageal reflux. RESULTS:Patients in the IOM subset featuring a majority of low-amplitude simultaneous contractions(LASC) experienced less heartburn(prevalence 26%) ,but more dysphagia(57%) than those in the IOM subset featuring low-amplitude propagated contractions(LAP;heartburn 70%,dysphagia 24%;both P ≤ 0.01) . LASC patients also experienced less heartburn and more dysphagia than patient controls(heartburn 68%,dysphagia 11%;both P < 0.001) . The prevalence of heartburn and dysphagia in IOM patients featuring a majority of non-transmitted sequences(NT) was 54%(P = 0.04 vs LASC) and 36%(P < 0.01 vs controls) ,respectively. No differences inage and gender distribution,chest pain prevalence,acid exposure time(AET) and symptom/reflux association existed between IOM subsets,or between subsets and controls. CONCLUSION:IOM patients with LASC exhibit a different symptom profile to those with LAP,but do not differ in gastro-oesophageal reflux prevalence. These findings raise the possibility of different pathophysiological mechanisms in IOM subsets,which warrants further investigation.展开更多
AIM:To study non-cardiac chest pain(NCCP) in relation to ineffective esophageal motility(IEM) and rapid food intake.METHODS:NCCP patients with a self-reported habit of fast eating underwent esophageal manometry for th...AIM:To study non-cardiac chest pain(NCCP) in relation to ineffective esophageal motility(IEM) and rapid food intake.METHODS:NCCP patients with a self-reported habit of fast eating underwent esophageal manometry for the diagnosis of IEM.Telephone interviews identified eating habits of additional IEM patients.Comparison of manometric features was done among IEM patients with and without the habit of rapid food intake and healthy controls.A case study investigated the effect of 6-mo gum chewing on restoration of esophageal motility in an IEM patient.The Valsalva maneuver was performed in IEM patients and healthy controls to assess the compliance of the esophagus in response to abdominal pressureincrease.RESULTS:Although most patients diagnosed with NCCP do not exhibit IEM,remarkably,all 12 NCCP patients who were self-reporting fast eaters with a main complaint of chest pain(75.0%) had contraction amplitudes in the mid and distal esophagus that were significantly lower compared with healthy controls [(23.45 mmHg(95%CI:14.06-32.85)vs 58.80 mmHg(95%CI:42.56-75.04),P < 0.01 and 28.29 mmHg(95%CI:21.77-34.81) vs 50.75 mmHg(95%CI:38.44-63.05),P < 0.01,respectively)].In 7 normal-eating IEM patients with a main complaint of sensation of obstruction(42.9%),the mid amplitude was smaller than in the controls [30.09 mmHg(95%CI:19.48-40.70) vs 58.80 mmHg(95%CI:42.56-75.04),P < 0.05].There was no statistically significant difference in manometric features between the fast-eating and normal-eating groups.One NCCP patient who self-reported fast eating and was subsequently diagnosed with IEM did not improve with proton-pump inhibition but restored swallow-induced contractions upon 6-mo gum-chewing.The Valsalva maneuver caused a markedly reduced pressure rise in the mid and proximal esophagus in the IEM patients.CONCLUSION:Habitual rapid food intake may lead to IEM.A prospective study is needed to validate this hypothesis.Gum-chewing might strengthen weakened esophageal muscles.展开更多
Administrative department, as the focus of national political system reform, is associated with optimization and adjustment of state institutions and plays a macro-control role in socialist economic development. Admin...Administrative department, as the focus of national political system reform, is associated with optimization and adjustment of state institutions and plays a macro-control role in socialist economic development. Administrative departments, just the "government", conduct economic control function to promote the sustainable development of social economic causes. The thesis firstly introduces administrative departments' era effect and causes of administrative departments' economic policy ineffectiveness. And on the basis of these, the thesis comes up with some solutions to solve economic ineffectiveness, hoping that it would be helpful to relevant researches.展开更多
The setting values of thresholds for fault feature parameters are critical in all kinds of protection schemes.When the detected feature parameter value exceeds the setting value,the protection will trip.However,the se...The setting values of thresholds for fault feature parameters are critical in all kinds of protection schemes.When the detected feature parameter value exceeds the setting value,the protection will trip.However,the setting value based conventional protection schemes sometimes cannot satisfy the protection requirements of neutral ineffectively earthed power systems(NIEPS)due to wide variations in operating conditions and the complexities of fault cases.In this paper,a novel single phase grounding fault protection scheme without threshold setting is proposed.The fault detection is achieved based on operating states rather than setting values.A fuzzy c-means algorithm is used to divide the operating state of the protected feeder into non-fault states and fault states.The cluster center of each state is then obtained by classifying the historical feature samples of the protected feeder extracted under various operating conditions into their corresponding states in a constructed multi-dimensional fault feature space.The distances between the detected feature samples and the cluster centers of the non-fault and the fault states are calculated.If the distance to the fault state is shorter than that to the non-fault state,a fault is detected.Otherwise,the feeder is considered normal.A PSCAD/EMTDC simulator is used to simulate a 35 kV NIEPS under various operating conditions,non-linear loads,and complex fault cases.Results show that the proposed single phase grounding fault protection scheme without threshold setting can protect the system correctly under all kinds of faults.展开更多
Esophageal motility abnormalities are among the main factors implicated in the pathogenesis of gastroesophageal reflux disease. The recent introduction in clinical and research practice of novel esophageal testing has...Esophageal motility abnormalities are among the main factors implicated in the pathogenesis of gastroesophageal reflux disease. The recent introduction in clinical and research practice of novel esophageal testing has markedly improved our understanding of the mechanisms contributing to the development of gastroesophageal reflux disease, allowing a better management of patients with this disorder. In this context, the present article intends to provide an overview of the current literature about esophageal motility dysfunctions in patients with gastroesophageal reflux disease. Esophageal manometry, by recording intraluminal pressure, represents the gold standard to diagnose esophagealmotility abnormalities. In particular, using novel techniques, such as high resolution manometry with or without concurrent intraluminal impedance monitoring, transient lower esophageal sphincter (LES) relaxations, hypotensive LES, ineffective esophageal peristalsis and bolus transit abnormalities have been better defined and strongly implicated in gastroesophageal reflux disease development. Overall, recent findings suggest that esophageal motility abnormalities are increasingly prevalent with increasing severity of reflux disease, from nonerosive reflux disease to erosive reflux disease and Barrett's esophagus. Characterizing esophageal dysmotility among different subgroups of patients with reflux disease may represent a fundamental approach to properly diagnose these patients and, thus, to set up the best therapeutic management. Currently, surgery represents the only reliable way to restore the esophagogastric junction integrity and to reduce transient LES relaxations that are considered to be the predominant mechanism by which gastric contents can enter the esophagus. On that ground, more in depth future studies assessing the pathogenetic role of dysmotility in patients with reflux disease are warranted.展开更多
AIM: To assess esophageal motility after esophageal endoscopic submucosal dissection (ESD). METHODS: Twelve patients (6 men and 6 women) aged 53-64 years (mean age, 58 years) who underwent regular examination 3-12 mo ...AIM: To assess esophageal motility after esophageal endoscopic submucosal dissection (ESD). METHODS: Twelve patients (6 men and 6 women) aged 53-64 years (mean age, 58 years) who underwent regular examination 3-12 mo after esophageal ESD for neoplasms of the esophageal body were included in this study. The ESD procedure was performed under deep sedation using a combination of propofol and fentanyl, and involved a submucosal injection to lift the lesion and use of a dual-knife and an insulated-tip knife to create a circumferential incision around the lesion extending into the submucosa. Esophageal motility was examined using a high-resolution manometry system. Dysphagia was graded using a five-point scale according to the Mellow and Pinkas scoring system. Patient symptoms and the results of esophageal manometry were then analyzed. RESULTS: Of the 12 patients enrolled, 1 patient hadgrade 2 dysphagia, 1 patient had grade 1 dysphagia, and 3 patients complained of sporadic dysphagia. Ineffective esophageal motility was observed in 5 of 6 patients with above semi-circumference of resection extension. Of these 5 patients, 1 patient complained of grade 2 dysphagia (with esophageal stricture), one patient complained of grade 1 dysphagia, and 3 patients complained of sporadic dysphagia. Normal esophageal body manometry was observed in all 6 patients with below semi-circumference of resection extension. The 6 patients with normal esophageal motility did not complain of dysphagia. CONCLUSION: Extensive esophageal ESD may cause esophageal dysmotility in some patients, and might also have an influence on dysphagia although without esophageal stricture.展开更多
Shipping industry has become more capital intensive, technically more demanding and subject to major global regulatory reforms. As a consequence, the number of African shipping lines has been severely reduced. Interna...Shipping industry has become more capital intensive, technically more demanding and subject to major global regulatory reforms. As a consequence, the number of African shipping lines has been severely reduced. International trade of the WCA countries remains weak, limited to 30% of their Gross Domestic Product (GDP). The goal of this paper is to provide a comprehensive overview of the port and shipping convey management in the WCA region, and of course to describe what has been achieved since then and what still have to be done to better its infrastructures and port community.展开更多
文摘Context/objectives: The fight against Chronic Non-Communicable Diseases (NCDs) is a long-term undertaking, which requires available, motivated and well-managed human resources (HR). The administrative management of skills on both qualitative and quantitative levels is one of the essential functions of a health system. To better implement policies of fight against High Blood Pressure (HBP) and other chronic diseases, it is important to establish strategies to retain health personnel. This loyalty requires favorable working conditions and consideration of the contribution-reward couple. Good working conditions are likely to reduce the phenomenon of medical nomadism;conversely, poor HR management can contribute to their exodus towards exotic “green pastures”, thus leading to an additional crisis in the Cameroonian health system. The fight against HBP is a complex, multifaceted and multifactorial reality that requires appropriate management model for all types of resources mainly HR. The main objective of this research is to show the impact of poor management of human resources in Cameroon health system on medical nomadism and the ineffectiveness of the fight against High Blood Pressure. Method: A cross-sectional descriptive survey among five hundred (500) health facilities in the center region of Cameroon has been conducted. A stratified probabilistic technique has been used, and the number of health facilities to be surveyed has been determined using the “sample size estimation table” of Depelteau. The physical questionnaires have been printed and then distributed to data collectors. After data collection, the latter were grouped during processing in Excel sheets. The Chi-square test was used for data with a qualitative value and that of Kolmogorov-Sminorf for data with a quantitative value to assess the normality and reliability of data. The Crochach’s Alpha reliability test allowed us to have a summary of the means and variances and then to search for intragroup correlations between variables. Descriptive analysis was possible with the XLSTAT 2016 software. Results: 43.60% of Health Facilities (HF) managers were unqualified. 82.20% of HF managers have staff in a situation of professional insecurity. They are mainly contractual (49.00), decision-making agents (24.40%), casual agents (08.80). The proportion of unstable personnel is average of 22.00% and very unstable, 12.00%.
文摘BACKGROUND Gastroesophageal reflux is associated with poorer outcomes after lung transplant,likely through recurrent aspiration and allograft injury.Although prior studies have demonstrated a relationship between impedance-pH results and transplant outcomes,the role of esophageal manometry in the assessment of lung transplant patients remains debated,and the impact of esophageal dysmotility on transplant outcomes is unclear.Of particular interest is ineffective esophageal motility(IEM)and its associated impact on esophageal clearance.AIM To assess the relationship between pre-transplant IEM diagnosis and acute rejection after lung transplantation.METHODS This was a retrospective cohort study of lung transplant recipients at a tertiary care center between 2007 and 2018.Patients with pre-transplant anti-reflux surgery were excluded.Manometric and reflux diagnoses were recorded from pre-transplant esophageal function testing.Time-to-event analysis using Cox proportional hazards model was applied to evaluate outcome of first episode of acute cellular rejection,defined histologically per International Society of Heart and Lung Transplantation guidelines.Subjects not meeting this endpoint were censored at time of post-transplant anti-reflux surgery,last clinic visit,or death.Fisher’s exact test for binary variables and student’s t-test for continuous variables were performed to assess for differences between groups.RESULTS Of 184 subjects(54%men,mean age:58,follow-up:443 person-years)met criteria for inclusion.Interstitial pulmonary fibrosis represented the predominant pulmonary diagnosis(41%).During the follow-up period,60 subjects(33.5%)developed acute rejection.The all-cause mortality was 16.3%.Time-to-event univariate analyses demonstrated significant association between IEM and acute rejection[hazard ratio(HR):1.984,95%CI:1.03-3.30,P=0.04],confirmed on Kaplan-Meier curve.On multivariable analysis,IEM remained independently associated with acute rejection,even after controlling for potential confounders such as the presence of acid and nonacid reflux(HR:2.20,95%CI:1.18-4.11,P=0.01).Nonacid reflux was also independently associated with acute rejection on both univariate(HR:2.16,95%CI:1.26-3.72,P=0.005)and multivariable analyses(HR:2.10,95%CI:1.21-3.64,P=0.009),adjusting for the presence of IEM.CONCLUSION Pre-transplant IEM was associated with acute rejection after transplantation,even after controlling for acid and nonacid reflux.Esophageal motility testing may be considered in lung transplant to predict outcomes.
文摘AIM: TO evaluate the association between IEM and gastropharyngeal reflux disease (GPRD) in patients who underwent ambulatory 24-h dual-probe pH monitoring for the evaluation of supraesophageal symptoms. METHODS: A total of 632 patients who underwent endoscopy, esophageal manometry and ambulatory 24-h dual-pH monitoring due to supraesophageal symptoms (e.g. globus, hoarseness, or cough) were enrolled. Of them, we selected the patients who had normal esophageal motility and IEM. The endoscopy and ambulatory pH monitoring findings were compared between the two groups. RESULTS;: A total of 264 patients with normal esophageal motility and 195 patients with the diagnosis of IEM were included in this study. There was no difference in the frequency of reflux esophagitis and hiatal hernia between the two groups. All the variables showing gastroesophageal reflux and gastropharyngeal reflux were not different between the two groups. The frequency of GERD and GPRD, as defined by ambulatory pH monitoring, was not different between the two groups. CONCLUSION: There was no association between IEM and GPRD as well as between IEM and GERD. IEM alone cannot be considered as a definitive marker for reflux disease.
文摘AIM:To compare the demographic and clinical features of different manometric subsets of ineffective oesophageal motility(IOM;defined as ≥ 30% wet swallows with distal contractile amplitude < 30 mmHg) ,and to determine whether the prevalence of gastro-oesophageal reflux differs between IOM subsets. METHODS:Clinical characteristics of manometric subsets were determined in 100 IOM patients(73 female,median age 58 years) and compared to those of 100 age-and gender-matched patient controls with oesophageal symptoms,but normal manometry. Supine oesophageal manometry was performed with an eight-channel DentSleeve water-perfused catheter,and an ambulatory pH study assessed gastro-oesophageal reflux. RESULTS:Patients in the IOM subset featuring a majority of low-amplitude simultaneous contractions(LASC) experienced less heartburn(prevalence 26%) ,but more dysphagia(57%) than those in the IOM subset featuring low-amplitude propagated contractions(LAP;heartburn 70%,dysphagia 24%;both P ≤ 0.01) . LASC patients also experienced less heartburn and more dysphagia than patient controls(heartburn 68%,dysphagia 11%;both P < 0.001) . The prevalence of heartburn and dysphagia in IOM patients featuring a majority of non-transmitted sequences(NT) was 54%(P = 0.04 vs LASC) and 36%(P < 0.01 vs controls) ,respectively. No differences inage and gender distribution,chest pain prevalence,acid exposure time(AET) and symptom/reflux association existed between IOM subsets,or between subsets and controls. CONCLUSION:IOM patients with LASC exhibit a different symptom profile to those with LAP,but do not differ in gastro-oesophageal reflux prevalence. These findings raise the possibility of different pathophysiological mechanisms in IOM subsets,which warrants further investigation.
文摘AIM:To study non-cardiac chest pain(NCCP) in relation to ineffective esophageal motility(IEM) and rapid food intake.METHODS:NCCP patients with a self-reported habit of fast eating underwent esophageal manometry for the diagnosis of IEM.Telephone interviews identified eating habits of additional IEM patients.Comparison of manometric features was done among IEM patients with and without the habit of rapid food intake and healthy controls.A case study investigated the effect of 6-mo gum chewing on restoration of esophageal motility in an IEM patient.The Valsalva maneuver was performed in IEM patients and healthy controls to assess the compliance of the esophagus in response to abdominal pressureincrease.RESULTS:Although most patients diagnosed with NCCP do not exhibit IEM,remarkably,all 12 NCCP patients who were self-reporting fast eaters with a main complaint of chest pain(75.0%) had contraction amplitudes in the mid and distal esophagus that were significantly lower compared with healthy controls [(23.45 mmHg(95%CI:14.06-32.85)vs 58.80 mmHg(95%CI:42.56-75.04),P < 0.01 and 28.29 mmHg(95%CI:21.77-34.81) vs 50.75 mmHg(95%CI:38.44-63.05),P < 0.01,respectively)].In 7 normal-eating IEM patients with a main complaint of sensation of obstruction(42.9%),the mid amplitude was smaller than in the controls [30.09 mmHg(95%CI:19.48-40.70) vs 58.80 mmHg(95%CI:42.56-75.04),P < 0.05].There was no statistically significant difference in manometric features between the fast-eating and normal-eating groups.One NCCP patient who self-reported fast eating and was subsequently diagnosed with IEM did not improve with proton-pump inhibition but restored swallow-induced contractions upon 6-mo gum-chewing.The Valsalva maneuver caused a markedly reduced pressure rise in the mid and proximal esophagus in the IEM patients.CONCLUSION:Habitual rapid food intake may lead to IEM.A prospective study is needed to validate this hypothesis.Gum-chewing might strengthen weakened esophageal muscles.
文摘Administrative department, as the focus of national political system reform, is associated with optimization and adjustment of state institutions and plays a macro-control role in socialist economic development. Administrative departments, just the "government", conduct economic control function to promote the sustainable development of social economic causes. The thesis firstly introduces administrative departments' era effect and causes of administrative departments' economic policy ineffectiveness. And on the basis of these, the thesis comes up with some solutions to solve economic ineffectiveness, hoping that it would be helpful to relevant researches.
基金supported in part by National Natural Science Foundation of China under Grant 61233008 and Grant 51277014.
文摘The setting values of thresholds for fault feature parameters are critical in all kinds of protection schemes.When the detected feature parameter value exceeds the setting value,the protection will trip.However,the setting value based conventional protection schemes sometimes cannot satisfy the protection requirements of neutral ineffectively earthed power systems(NIEPS)due to wide variations in operating conditions and the complexities of fault cases.In this paper,a novel single phase grounding fault protection scheme without threshold setting is proposed.The fault detection is achieved based on operating states rather than setting values.A fuzzy c-means algorithm is used to divide the operating state of the protected feeder into non-fault states and fault states.The cluster center of each state is then obtained by classifying the historical feature samples of the protected feeder extracted under various operating conditions into their corresponding states in a constructed multi-dimensional fault feature space.The distances between the detected feature samples and the cluster centers of the non-fault and the fault states are calculated.If the distance to the fault state is shorter than that to the non-fault state,a fault is detected.Otherwise,the feeder is considered normal.A PSCAD/EMTDC simulator is used to simulate a 35 kV NIEPS under various operating conditions,non-linear loads,and complex fault cases.Results show that the proposed single phase grounding fault protection scheme without threshold setting can protect the system correctly under all kinds of faults.
文摘Esophageal motility abnormalities are among the main factors implicated in the pathogenesis of gastroesophageal reflux disease. The recent introduction in clinical and research practice of novel esophageal testing has markedly improved our understanding of the mechanisms contributing to the development of gastroesophageal reflux disease, allowing a better management of patients with this disorder. In this context, the present article intends to provide an overview of the current literature about esophageal motility dysfunctions in patients with gastroesophageal reflux disease. Esophageal manometry, by recording intraluminal pressure, represents the gold standard to diagnose esophagealmotility abnormalities. In particular, using novel techniques, such as high resolution manometry with or without concurrent intraluminal impedance monitoring, transient lower esophageal sphincter (LES) relaxations, hypotensive LES, ineffective esophageal peristalsis and bolus transit abnormalities have been better defined and strongly implicated in gastroesophageal reflux disease development. Overall, recent findings suggest that esophageal motility abnormalities are increasingly prevalent with increasing severity of reflux disease, from nonerosive reflux disease to erosive reflux disease and Barrett's esophagus. Characterizing esophageal dysmotility among different subgroups of patients with reflux disease may represent a fundamental approach to properly diagnose these patients and, thus, to set up the best therapeutic management. Currently, surgery represents the only reliable way to restore the esophagogastric junction integrity and to reduce transient LES relaxations that are considered to be the predominant mechanism by which gastric contents can enter the esophagus. On that ground, more in depth future studies assessing the pathogenetic role of dysmotility in patients with reflux disease are warranted.
文摘AIM: To assess esophageal motility after esophageal endoscopic submucosal dissection (ESD). METHODS: Twelve patients (6 men and 6 women) aged 53-64 years (mean age, 58 years) who underwent regular examination 3-12 mo after esophageal ESD for neoplasms of the esophageal body were included in this study. The ESD procedure was performed under deep sedation using a combination of propofol and fentanyl, and involved a submucosal injection to lift the lesion and use of a dual-knife and an insulated-tip knife to create a circumferential incision around the lesion extending into the submucosa. Esophageal motility was examined using a high-resolution manometry system. Dysphagia was graded using a five-point scale according to the Mellow and Pinkas scoring system. Patient symptoms and the results of esophageal manometry were then analyzed. RESULTS: Of the 12 patients enrolled, 1 patient hadgrade 2 dysphagia, 1 patient had grade 1 dysphagia, and 3 patients complained of sporadic dysphagia. Ineffective esophageal motility was observed in 5 of 6 patients with above semi-circumference of resection extension. Of these 5 patients, 1 patient complained of grade 2 dysphagia (with esophageal stricture), one patient complained of grade 1 dysphagia, and 3 patients complained of sporadic dysphagia. Normal esophageal body manometry was observed in all 6 patients with below semi-circumference of resection extension. The 6 patients with normal esophageal motility did not complain of dysphagia. CONCLUSION: Extensive esophageal ESD may cause esophageal dysmotility in some patients, and might also have an influence on dysphagia although without esophageal stricture.
文摘Shipping industry has become more capital intensive, technically more demanding and subject to major global regulatory reforms. As a consequence, the number of African shipping lines has been severely reduced. International trade of the WCA countries remains weak, limited to 30% of their Gross Domestic Product (GDP). The goal of this paper is to provide a comprehensive overview of the port and shipping convey management in the WCA region, and of course to describe what has been achieved since then and what still have to be done to better its infrastructures and port community.