In this paper is proposed a new method for functional connectivity detection using regression analysis. First, the resting state functional magnetic resonance imaging (fMRI) data from each voxel is passed through a bandpass filter to obtain frequencies between 0.01 Hz and 0.1 Hz. Then, the region of interest (ROI) is defined and the mean time course of all voxels in ROI is used as a regressor. Finally, the linear relationship between the time course of other voxels and the regressor in the resting brain is estimated. By the application of this new method in simulation data and fMRI data, the relevant validity and reliability are demonstrated.
Brain ; physiology ; Humans ; Image Processing, Computer-Assisted ; Magnetic Resonance Imaging ; methods ; Regression Analysis ; Signal Processing, Computer-Assisted

Objective:To investigate the safety and short-term efficacy of laparoscopic pro-ximal gastrectomy (LPG) for proximal gastric cancer and adenocarcinoma of esophagogastric junction.Methods:The retrospective cohort study was conducted. The clinicopathological data of 385 patients with proximal gastric cancer and adenocarcinoma of esophagogastric junction who underwent LPG in the 15 medical centers, including the First Affiliated Hospital of Xiamen University et al, from January 2014 to March 2022 were collected. There were 304 males and 81 females, aged (63±9)years. Of the 385 patients, 335 cases undergoing LPG were divided into the laparoscopic group and 50 cases undergoing open proximal gastrectomy were divided into the open group. Observation indicators: (1) intraoperative and postoperative situations; (2) follow-up; (3) stratified analysis. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M(range), and comparison between groups was conducted using the Wilcoxon rank sum test. Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test or Fisher exact probability. Repeated measurement data were analyzed using the repeated ANOVA. Results:(1) Intraoperative and postoperative situations. The operation time, cases with reconstruction of digestive tract as esophagogastric anastomosis and esophageal-jejunal anastomosis, cases with postoperative pathological staging as stage 0?Ⅰ and stage Ⅱ?Ⅲ, duration of postoperative hospital stay, cases with postoperative early complications were (212±96)minutes, 270, 65, 177, 107, 10(range, 8?14)days, 40 in patients of the laparoscopic group, with 51 cases missing the data of postoperative pathological staging. The above indicators were (174±90)minutes, 39, 11, 22, 28, 10(range, 8?18)days, 10 in patients of the open group. There were significant differences in the opera-tion time and postoperative pathological staging between the two groups ( t=2.62, χ2=5.93, P<0.05), and there was no significant difference in the reconstruction of digestive tract, duration of post-operative hospital stay, postoperative early complications between the two groups ( χ2=0.19, Z=0.40, χ2=2.50, P>0.05). (2) Follow-up. Of the 385 patients,202 cases were followed up during the post-operative 12 months, including 187 cases in the laparoscopic group and 15 cases in the open group. Cases with reflux esophagitis, cases with esophageal anastomotic stenosis were 48, 11 in patients of the laparoscopic group, versus 5, 2 in patients of the open group, showing no significant difference in the above indicators between the two groups ( P>0.05). The body mass index (BMI), hemoglobin (Hb), albumin (Alb) at postoperative 6 months and 12 months were (21±3)kg/m 2, (130±15)g/L, (40±4)g/L and (21±3)kg/m 2, (132±14)g/L, (41±4)g/L in patients of the laparoscopic group, versus (21±3)kg/m 2, (121±19)g/L, (37±5)g/L and (21±3)kg/m 2, (125±21)g/L, (43±6)g/L in patients of the open group. There were significant differences in postoperative Hb between the two groups ( Fgroup=5.88, Ftime=5.49, Finteraction=19.95, P<0.05) and there were significant differences in time effect of postopera-tive BMI and Alb between the two groups ( Ftime=9.53, 49.88, P<0.05). (3) Stratified analysis. ① Incidence of postoperative of reflux esophagitis and esophageal anastomotic stenosis in patients with different reconstruction of digestive tract. Of the 202 patients, cases with reconstruction of digestive tract as esophagogastric anastomosis and esophageal-jejunal anastomosis were 168 and 34, respectively. The incidence rates of postoperative of reflux esophagitis were 26.79%(45/168)and 23.53%(8/34)in cases with reconstruction of digestive tract as esophagogastric anastomosis and esophageal-jejunal anastomosis, showing no significant difference between them ( χ2=0.16, P>0.05). Cases undergoing esophageal anastomotic stenosis were 13 in patients with reconstruction of diges-tive tract as esophagogastric anastomosis. ② The BMI, Hb, Alb in patients with different reconstruc-tion of digestive tract. The BMI, Hb, Alb were (24±3)kg/m 2, (135±20)g/L, (41±5)g/L in the 168 patients with reconstruction of digestive tract as esophagogastric anastomosis before the operation, versus (23±3)kg/m 2, (130±19)g/L, (40±4)g/L in the 34 patients with reconstruction of digestive tract as esophageal-jejunal anastomosis before the operation, showing no significant difference between them ( t=1.44, 1.77, 1.33, P>0.05). The BMI, Hb, Alb at postoperative 6 months and 12 months were (21±3)kg/m 2, (128±16)g/L, (39±4)g/L and (21±3)kg/m 2, (131±16)g/L, (41±4)g/L in the 168 patients with reconstruction of digestive tract as esophagogastric anastomosis, versus (20±4)kg/m 2, (133±13)g/L, (43±3)g/L and (21±3)kg/m 2, (135±12)g/L, (44±3)g/L in the 34 patients with reconstruction of digestive tract as esophageal-jejunal anastomosis. There were significant differences in the group effect and time effect of postoperative Alb between patients with different reconstruction of diges-tive tract ( Fgroup=15.82, Ftime=5.43, P<0.05), and there was also a significant difference in the time effect of postoperative BMI between them ( Ftime=4.22 , P<0.05). Conclusion:LPG can be used to the treatment of proximal gastric cancer and adenocarcinoma of esophagogastric junction, with a good safety and short-term efficacy.