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The Middle Triassic Luoping Biota in south-west China represents the inception of modern marine ecosystems, with abundant and diverse arthropods, fishes and marine reptiles, indicating recovery from the Permian–Triassic mass extinction. Here we report a new specimen of the predatory marine reptile Diandongosaurus, based on a nearly complete skeleton. The specimen is larger than most other known pachypleurosaurs, and the body shape, caniniform teeth, clavicle with anterior process, and flat distal end of the anterior caudal ribs show its affinities with Diandongosaurus acutidentatus, while the new specimen is approximately three times larger than the holotype. The morphological characters indicate that the new specimen is an adult of D. acutidentatus, allowing for ontogenetic variation. The fang-like teeth and large body size confirm it was a predator, but the amputated hind limb on the right side indicate itself had been predated by an unknown hunter. Predation on such a large predator reveals that predation pressure in the early Mesozoic was intensive, a possible early hint of the Mesozoic Marine Revolution.

To compare the safety and efficiency of pacing at right ventricular outflow versus right ventricular apex.Patients were divided into two groups: pacing at ventricular cardiac apex (common pacing group, n = 22) and pacing at right ventricular outflow tract (uncommon pacing group, n = 18).Impedance and amplitude of R-wave were similar during implantation between the two groups (all P0.05). The pacing threshold and electric current were significant higher in uncommon group than those in common pacing group (all P0.05), however, these differences disappeared at 1 month post pacemaker implantation (all P0.05). The mean QRS duration tended to be shorter in uncommon pacing group compared to that in common pacing group (P0.05). There was no pacemaker associated adverse effect in both groups.The safety and efficiency of pacing at right ventricular outflow was similar as those of pacing at right ventricular apex.

To verify the electric synchronism, mechanic synchronism and hemodynamics of selective site pacing.Pacing in the right ventricular cardiac apex (RVA), the right ventricular His bundle region (His), and the septum of right ventricular high-positioned outflow tract (RVOT), CO and CI were recorded. The electrical synchronism was assessed by observing the width and shape in a 12-lead surface ECG. The mechanical synchronism was estimated by using the VVI (vector velocity imaging) technology of the Acuson Sequia 512.The results showed that CO and CI were lower while pacing in RVA, but they were not significant different (P0.05). The QRS width: (124 +/- 5.3) ms while pacing in His, (144 +/- 7.1) ms while pacing in RVOT and (156 +/- 8.6) ms while pacing in RVA. The QRS width while pacing in His and in RVOT were narrower than in RVA and there were significant differences (P0.01). Vector velocity imaging showed that mechanical synchronism was better while pacing in RVOT than that in RVA.Pacing in RVOT seems better than pacing in traditional RVA, and the operation was no more difficult than the traditional operation.