Three functional models, polynomial, spectral analysis, and modified AR model, are studied and compared in fitting and predicting clock deviation based on the data sequence derived from two-way satellite time and freq...Three functional models, polynomial, spectral analysis, and modified AR model, are studied and compared in fitting and predicting clock deviation based on the data sequence derived from two-way satellite time and frequency transfer. A robust equivalent weight is applied, which controls the significant influence of outlying observations. Some conclusions show that the prediction precision of robust estimation is better than that of LS. The prediction precision calculated from smoothed observations is higher than that calculated from sampling observations. As a count of the obvious period variations in the clock deviation sequence, the predicted values of polynomial model are implausible. The prediction precision of spectral analysis model is very low, but the principal periods can be determined. The prediction RMS of 6-hour extrapolation interval is Ins or so, when modified AR model is used.展开更多
Introduction: Patients with constipation often report dyspeptic symptoms, but whether constipation is associated with specific dyspeptic symptoms and altered gastrointestinal (GI) motility, remains to be established. ...Introduction: Patients with constipation often report dyspeptic symptoms, but whether constipation is associated with specific dyspeptic symptoms and altered gastrointestinal (GI) motility, remains to be established. Our aim was to study symptoms association and GI motility parameters in patients with constipation and functional dyspepsia. Patients and Method: 42 patients with different symptoms and severity of constipation and dyspepsia were enrolled. Scintigraphic gastric emptying, colonic transit time and gallbladder contraction were studied in all subjects. Results: No significant association was observed between individual symptoms of constipation and dyspepsia. Patients with more severe constipation did not have higher dyspepsia severity scores. Colonic transit time, gastric half emptying and gallbladder contraction were not significantly correlated. Although patients with severe nausea had faster colonic transit than those with absent/mild symptom (19 ± 2 vs. 48 ± 7 h; p < 0.05), the multivariate analysis only revealed a significant association between severe postprandial fullness, delayed t 1/2 (OR1.05, CI 1- 1.1) and impaired gallbladder contraction (OR 0.94, CI 0.89- 0.99). Conclusions: Constipation was not associated with severity, or any particular dyspeptic symptom. Although motor abnormalities of both colon and proximal GI tract regions existed in the subset of constipated dyspeptic patients, they did not seem associated with the genesis of different dyspeptic symptoms.展开更多
Background: In GERD patients, ineffective esophageal motility(IEM), a hypocont ractile disorder, is the most common motor abnormality. IEM has been associated with reflux in both the supine and upright position, prolo...Background: In GERD patients, ineffective esophageal motility(IEM), a hypocont ractile disorder, is the most common motor abnormality. IEM has been associated with reflux in both the supine and upright position, prolonged esophageal cleara nce,and delayed of bolus transport. IEM has been equally present in erosive and in nonerosive GERD. Goal: Considering that reflux has been found to be more seve re in erosive GERD than in nonerosive GERD patients and that IEM delays esophage al clearance, our hypothesis is that patients with erosive GERD have more severe IEM than those with nonerosive disease.Study: A retrospective review of consecu tive manometries of patients with the chief complaint of heartburn and a diagnos is of IEM were performed, and patients with both erosive and nonerosive GERD wer e selected. According to the number of ineffective contractions, IEM was stratif ied into three groups:30%to 40%, mild; 50%to 60%, moderate; and greater than 60%, severe. We also registered the number of low amplitude,failed, and normal waves in each manometry of both groups.We evaluated 110 patients: 70 (64%) wit h erosive GERD and 40 (36%)with nonerosive GERD. The percentage of mild,moderat e and severe IEM was similar in erosive and in nonerosive GERD patients, as well the number of low amplitude, failed or normal waves (P< 0.5). Conclusion: There were no differences between the severity of IEM in erosive and in nonerosive GE RD patients.展开更多
基金Supported by the National Natural Science Foundations of China （No. 40474001, No. 40274002, No. 40604003）.
文摘Three functional models, polynomial, spectral analysis, and modified AR model, are studied and compared in fitting and predicting clock deviation based on the data sequence derived from two-way satellite time and frequency transfer. A robust equivalent weight is applied, which controls the significant influence of outlying observations. Some conclusions show that the prediction precision of robust estimation is better than that of LS. The prediction precision calculated from smoothed observations is higher than that calculated from sampling observations. As a count of the obvious period variations in the clock deviation sequence, the predicted values of polynomial model are implausible. The prediction precision of spectral analysis model is very low, but the principal periods can be determined. The prediction RMS of 6-hour extrapolation interval is Ins or so, when modified AR model is used.
文摘Introduction: Patients with constipation often report dyspeptic symptoms, but whether constipation is associated with specific dyspeptic symptoms and altered gastrointestinal (GI) motility, remains to be established. Our aim was to study symptoms association and GI motility parameters in patients with constipation and functional dyspepsia. Patients and Method: 42 patients with different symptoms and severity of constipation and dyspepsia were enrolled. Scintigraphic gastric emptying, colonic transit time and gallbladder contraction were studied in all subjects. Results: No significant association was observed between individual symptoms of constipation and dyspepsia. Patients with more severe constipation did not have higher dyspepsia severity scores. Colonic transit time, gastric half emptying and gallbladder contraction were not significantly correlated. Although patients with severe nausea had faster colonic transit than those with absent/mild symptom (19 ± 2 vs. 48 ± 7 h; p < 0.05), the multivariate analysis only revealed a significant association between severe postprandial fullness, delayed t 1/2 (OR1.05, CI 1- 1.1) and impaired gallbladder contraction (OR 0.94, CI 0.89- 0.99). Conclusions: Constipation was not associated with severity, or any particular dyspeptic symptom. Although motor abnormalities of both colon and proximal GI tract regions existed in the subset of constipated dyspeptic patients, they did not seem associated with the genesis of different dyspeptic symptoms.
文摘Background: In GERD patients, ineffective esophageal motility(IEM), a hypocont ractile disorder, is the most common motor abnormality. IEM has been associated with reflux in both the supine and upright position, prolonged esophageal cleara nce,and delayed of bolus transport. IEM has been equally present in erosive and in nonerosive GERD. Goal: Considering that reflux has been found to be more seve re in erosive GERD than in nonerosive GERD patients and that IEM delays esophage al clearance, our hypothesis is that patients with erosive GERD have more severe IEM than those with nonerosive disease.Study: A retrospective review of consecu tive manometries of patients with the chief complaint of heartburn and a diagnos is of IEM were performed, and patients with both erosive and nonerosive GERD wer e selected. According to the number of ineffective contractions, IEM was stratif ied into three groups:30%to 40%, mild; 50%to 60%, moderate; and greater than 60%, severe. We also registered the number of low amplitude,failed, and normal waves in each manometry of both groups.We evaluated 110 patients: 70 (64%) wit h erosive GERD and 40 (36%)with nonerosive GERD. The percentage of mild,moderat e and severe IEM was similar in erosive and in nonerosive GERD patients, as well the number of low amplitude, failed or normal waves (P< 0.5). Conclusion: There were no differences between the severity of IEM in erosive and in nonerosive GE RD patients.
