Double-network hydrogels (DN gels), despite their high water content, are the strongest and toughest soft and wet materials available. However, in conventional DN gels, which show extraordinarily high mechanical performance comparable to that of industrial rubbers, the fi rst network must be a strong polyelectrolyte and this requirement greatly hinders the widespread application of these gels. A general method involving the use of a "molecular stent" for the synthesis of tough DN gels using any hydrophilic polymer as the fi rst network is reported. This is the fi rst reported method for the synthesis of tough DN gels using various neutral or weak polyelectrolyte hydrogels as the fi rst network. This method helps extend the DN gel concept to various functional polymers and may increase the number of applications of hydrogels in various fi elds.

No abstract

The identification of activity locations in continuous GPS trajectories is an essential preliminary step in obtaining person trip data and for activity-based transportation demand forecasting. In this research, a two-step methodology for identifying activity stop locations is proposed. In the first step, an improved density-based spatial clustering of applications with noise (DBSCAN) algorithm identifies stop points and moving points; then in the second step, the support vector machines (SVMs) method distinguishes activity stops from non-activity stops among the identified stop points. A time sequence constraint and a direction change constraint are applied as improvements to DBSCAN (yielding an improved algorithm known as C-DBSCAN). Then three major features are extracted for use in the SVMs method: stop duration, mean distance to the centroid of a cluster of points at a stop location, and the shorter of distances from current location to home and to the workplace. The proposed methodology was tested using GPS data collected from mobile phones in the Nagoya area of Japan. The C-DBSCAN algorithm achieves an accuracy of 90 % in identifying stop points in the first step, while the SVMs method is 96 % accurate in distinguishing the locations of activity stops from non-activity stops in the second step. Compared to other variants of DBSCAN used to identify activity locations from GPS trajectories, this two-step method is generally superior.

Background/AimsThe association between clinical symptoms, gastric emptying, quality of life and sleep disorders in distinct functional dyspepsia (FD) patients has not been studied yet in detail.MethodsWe enrolled 79 FD patients (postprandial distress syndrome [PDS], n = 65; epigastric pain syndrome [EPS], n = 47; EPS-PDS overlap, n = 33) and 44 healthy volunteers. Gastric motility was evaluated. We used Rome III criteria to evaluate clinical symptoms and State-Trait Anxiety Inventory (STAI) scores to determine anxiety status. Sleep disorder was evaluated using the Pittsburgh Sleep Quality Index scores.ResultsThere were no significant differences in age, sex and Helicobacter pylori positivity between FD subtypes and healthy volunteers. The scores of Glasgow dyspepsia severity scores (GDSS), SF-8 and Pittsburgh Sleep Quality Index (PSQI) in distinct subtypes of FD patients were significantly different from those in healthy volunteers. However, there were not significant differences in these scores, Tmax and T1/2 among 3 subtypes of FD patients. PSQI score was significantly (P = 0.027, P = 0.002 and P = 0.039, respectively) associated with GDSS among EPS, PDS and EPS-PDS overlap patients. In addition, 8-item short form health survey (SF-8; Physical Component Score and Mental Component Score) was significantly associated with global PSQI score in PDS and EPS-PDS overlap patients. In contrast, SF-8 (Mental Component Score) only was significantly linked to global PSQI score in EPS patients.ConclusionsPrevalences for sleep disorders, gastric motility and quality of life in 3 subtypes of FD patients were similar levels. In PDS and EPS-PDS overlap patients, SF-8 was significantly associated with global PSQI score.

There was not available data about the overlap between functional dyspepsia (FD) and pancreatic diseases. We aimed to determine whether epigastric pain syndrome (EPS) accompanying with pancreatic enzyme abnormalities were associated with early chronic pancreatitis proposed by Japan Pancreas Society (JPS) using endosonography. We enrolled 99 consecutive patients presenting with typical symptoms of FD, including patients with postprandial distress syndrome (PDS) (n = 59), EPS with pancreatic enzyme abnormalities (n = 41) and EPS without pancreatic enzyme abnormalities (n = 42) based on Rome III criteria. Gastric motility was evaluated using the 13C-acetate breath test. Early chronic pancreatitis was detected by endosonography and graded from 0 to 7. The ratio of female patients among EPS patients (34/41) with pancreatic enzyme abnormalities was significantly (p = 0.0018) higher than the ratio of female EPS patients (20/42) without it. Postprandial abdominal distention and physical component summary (PCS) scores in EPS patients with pancreatic enzyme abnormalities were significantly disturbed compared to those in EPS patients without it. Interestingly, AUC5 and AUC15 values (24.85 ± 1.31 and 56.11 ± 2.51, respectively) in EPS patients with pancreatic enzyme abnormalities were also significantly (p = 0.002 and p = 0.001, respectively) increased compared to those (19.75 ± 1.01 and 47.02 ± 1.99, respectively) in EPS patients without it. Overall, 64% of EPS patients with pancreatic enzyme abnormalities were diagnosed by endosonography as having concomitant early chronic pancreatitis proposed by JPS. Further studies are warranted to clarify how EPS patients with pancreatic enzyme abnormalities were associated with early chronic pancreatitis proposed by JPS.