Photoreduction of inorganic carbon(+IV) by elemental sulfur: Implications for prebiotic synthesis in terrestrial hot springs.

Terrestrial hydrothermal systems have been proposed as alternative birthplaces for early life but lacked reasonable scenarios for the supply of biomolecules. Here, we show that elemental sulfur (S0), as the dominant mineral in terrestrial hot springs, can reduce carbon dioxide (CO2) into formic acid (HCOOH) under ultraviolet (UV) light below 280 nm. The semiconducting S0 is indicated to have a direct bandgap of 4.4 eV. The UV-excited S0 produces photoelectrons with a highly negative potential of -2.34 V (versus NHE, pH 7), which could reduce CO2 after accepting electrons from electron donors such as reducing sulfur species. Simultaneously, UV light breaks sulfur bonds, benefiting the adsorption of charged carbonates onto S0 and assisting their photoreduction. Assuming that terrestrial hot springs covered 1% of primitive Earth's surface, S0 at 10 µM could have produced maximal 109 kg/year HCOOH within 10-cm-thick photic zones, underlying its remarkable contributions to the accumulation of prebiotic biomolecules.

Effects of dopamine, norepinephrine and dobutamine on gastric mucosal pH of septic shock patients.

The effect of different vasoactive drugs on the pH [intracellular pH (pHi)] of gastric mucosa in patients with septic shock was evaluated in the present study. According to the vasoactive drugs applied, 48 patients with septic shock were divided into 3 groups: A, B and C, with 16 cases each. Cases of group A were treated with dopamine, those of group B with norepinephrine while those of group C were treated with norepinephrine plus dobutamine. The changes of pH of gastric mucosa were observed before treatment (baseline) and 6, 12, 24 and 48 h after treatment, and the hemodynamic indicators were observed before treatment (baseline) and 6 h after administration. The gastric mucosal pH was not significantly different between two of the three groups before treatment (each at P>0.05). The gastric mucosal pH of group A did not change 6, 12, 24 and 48 h after treatment with drugs compared with the baseline (all at P>0.05), while the gastric mucosal pH in groups B and C were each statistically higher at the time points of 6, 12, 24 and 48 h after treatment with drugs compared with the respective baselines (all at P<0.05). Following treatment with drugs, the gastric mucosal pH of group C at all the time points of 6, 12, 24 and 48 h after treatment were significantly higher than those of groups A and B at the same time points after treatment, while there were some statistical differences between groups A and B at these time points (6, 12, 24 and 48 h after treatment; P<0.05). The hemodynamic indicators of the patients before treatment were not significantly different between two of the three groups (all at P>0.05). Compared with the baseline values, the mean arterial pressure and the cardiac index of each group after treatment were significantly increased, the pulmonary capillary wedge pressure and the central venous pressure of groups B and C significantly increased (all at P<0.05) and the heart rate of group A was significantly increased (P<0.05). In conclusion, the gastric mucosal pH of the septic shock patients was increased when treated with norepinephrine or with dobutamine. Additionally, the gastric mucosal pH was significantly higher when the patients were treated with dobutamine and norepinephrine in combination than with norepinephrine or dopamine alone. Dopamine, norepinephrine and dobutamine can improve the systemic hemodynamic conditions in patients with septic shock.

Laparoscopic surgery is more advantageous than laparotomic surgery for treatment of hypersplenism with gallstones.

BACKGROUND: The aim of this study was to compare laparoscopic vs. laparotomic surgery for the treatment of hypersplenism with gallstones. METHODS: Forty patients were treated with splenectomy and cholecystectomy using either totally laparoscopic surgery (laparoscopic group) or laparotomy (laparotomy group). The outcomes were duration of the surgery, intraoperative bleeding volume, postoperative complications, and number of postoperative hospitalization days. RESULTS: There was no difference in the duration of the surgery between both groups. No patient experienced intraoperative complications. There were postoperative pleural effusions (N.=3) and bleeding at the puncture site (N.=1) in laparoscopic group, and postoperative pleural effusions (N.=2), incision infection (N.=2) and peritoneal effusion (N.=1) in laparotomy group. The length of postoperative hospitalization was markedly shorter in laparoscopic group. The follow-up for 3 to 15 months after the surgery demonstrated that hypersplenism was corrected in all patients. All blood markers (white blood cells, platelets, and hemoglobin) recovered to normal levels. The portal vein thrombosis occurred in 6 patients of laparoscopic group and 5 patients of laparotomy group; this was controlled by oral administration of Warfarin and enteric coated Aspirin capsules. CONCLUSIONS: Treatment efficacy is comparable between laparoscopic surgery and traditional laparotomy. Laparoscopic surgery is more advantageous because of smaller trauma, faster postoperative recovery, and minimal invasiveness.

[Short-term efficacy comparison of laparoscopic-assisted versus open distal gastrectomy].

OBJECTIVE: To compare the short-term efficacy of laparoscopic-assisted verus open distal gastrectomy for gastric cancer. METHODS: The data of 29 patients with distal gastric cancer from January 2008 to October 2010 were analyzed. RESULTS: Twenty-eight underwent laparoscopic-assisted distal gastrectomy while 1 was switched to open surgery. The operative duration was (253.1 ± 32.6) min and the blood loss volume (268.5 ± 101.4) ml. The postoperative recovery time of gastrointestinal peristalsis was (2.1 ± 0.6) d. The length of incision was (5.6 ± 1.6) cm, the hospital stay duration (10.6 ± 2.4) d and the number of dissected lymph nodes (34.5 ± 5.2). CONCLUSION: Laparoscopic-assisted distal gastrectomy for gastric cancer is both safe and feasible. And it offers many advantages of minimal invasion, less pain and shorter hospital stay.