Muon Creation in Supernova Matter Facilitates Neutrino-Driven Explosions.

Muons can be created in nascent neutron stars (NSs) due to the high electron chemical potentials and the high temperatures. Because of their relatively lower abundance compared to electrons, their role has so far been ignored in numerical simulations of stellar core collapse and NS formation. However, the appearance of muons softens the NS equation of state, triggers faster NS contraction, and thus leads to higher luminosities and mean energies of the emitted neutrinos. This strengthens the postshock heating by neutrinos and can facilitate explosions by the neutrino-driven mechanism.

Recent improvements of the JET lithium beam diagnostic.

A 60 kV neutral lithium diagnostic beam probes the edge plasma of JET for the measurement of electron density profiles. This paper describes recent enhancements of the diagnostic setup, new procedures for calibration and protection measures for the lithium ion gun during massive gas puffs for disruption mitigation. New light splitting optics allow in parallel beam emission measurements with a new double entrance slit CCD spectrometer (spectrally resolved) and a new interference filter avalanche photodiode camera (fast density and fluctuation studies).

A randomized, double-blind, close-ranging, pilot study of intravenous granisetron in the prevention of postoperative nausea and vomiting in patients abdominal hysterectomy.

BACKGROUND AND OBJECTIVE: Postoperative nausea and vomiting (PONV) is a frequent and unpleasant experience that may increase postoperative complications and costs. For surgical procedures with a high risk of PONV, prevention is preferable to treatment. In this study, the authors explore the dose-response relationship between granisetron administered just prior to the end of surgery and post-operative nausea and vomiting in patients undergoing abdominal hysterectomy. METHODS: This was a randomized, double-blind, placebo-controlled, pilot study of post-operative nausea and vomiting prevention. Patients undergoing elective open abdominal hysterectomy requiring general anaesthesia received a single dose of granisetron 0.1, 0.2 or 0.3 mg or placebo administered approximately 15 min prior to the end of surgery. The primary efficacy end-point was the proportion of patients with no vomiting in the 0--6 h interval following medication administration. No inferential statistics were planned. RESULTS: The proportion of patients with no vomiting episode in the 0--6 h interval after administration of study medication was higher in each granisetron treatment group (>90%) than in the placebo group (77%). Proportions of patients with no vomiting episodes in the 0--24 h interval were similar across treatment groups. Results of analyses of proportions of patients with no moderate or severe nausea episodes, proportions of those requiring rescue medication and times to first use of rescue medication suggested a treatment effect of granisetron relative to placebo in both the 0--6 and 0--24 h intervals. Similar proportions of patients in each treatment group reported at least one adverse event. CONCLUSIONS: Granisetron at doses of 0.1, 0.2 and 0.3 mg administered just prior to the end of surgery suggested a trend of improved efficacy compared to placebo in preventing postoperative nausea and vomiting in the first 6 h after abdominal hysterectomy. This pilot study did not identify a dose-response relationship.

A comparison of the efficacy, safety, and patient satisfaction of ondansetron versus droperidol as antiemetics for elective outpatient surgical procedures. S3A-409 and S3A-410 Study Groups.

UNLABELLED: Two identical, randomized, double-blind, placebo-controlled studies enrolled 2061 adult surgical outpatients at high risk of postoperative nausea and vomiting (PONV) to compare i.v. ondansetron 4 mg with droperidol 0.625 mg and droperidol 1.25 mg for the prevention of PONV. The antiemetic drugs or placebo were administered i.v. 20 min before the induction of anesthesia with a barbiturate compound, followed by maintenance with N2O/isoflurane/enflurane. Nausea, emetic episodes, adverse events, and patient satisfaction were analyzed for the 0 to 2 h and 0 to 24 h postoperative periods. In the 0 to 2 h postoperative period, there was a complete response (no emesis or rescue antiemetic) in 46% of subjects given placebo (P < 0.05 versus antiemetic groups), in 62% given ondansetron, in 63% given droperidol 0.625 mg, and in 69% given droperidol 1.25 mg (P < 0.05 versus ondansetron). In the 0 to 24-h postoperative period, there were no significant differences in complete response between the ondansetron and droperidol 0.625 or 1.25 mg groups; all groups remained superior to placebo. The proportion of patients without nausea during the 0 to 24 h postoperative period was greater in the antiemetic groups compared with the placebo group; however, droperidol 1.25 mg was more effective than ondansetron 4 mg or droperidol 0.625 mg (43% vs 29% or 29%, respectively). Headache incidence was higher in the ondansetron group compared with either droperidol group. Patient satisfaction scores did not differ significantly among antiemetic treatment groups, although all were superior to placebo. In conclusion, all antiemetic treatment regimens were superior to placebo for the prevention of PONV in the immediate postoperative period; however, droperidol 1.25 mg was more efficacious than ondansetron during the early recovery period (0-2 h). There were no significant differences between ondansetron and either droperidol dose for emesis prevention during the 0 to 24 h postoperative period. IMPLICATIONS: More than 2000 patients at high risk of postoperative nausea and vomiting were given either placebo, ondansetron 4 mg, or droperidol 0.625 mg or 1.25 mg i.v. before the administration of general anesthesia. After surgery, the incidence of nausea, vomiting, medication side effects, and patient satisfaction were evaluated for 24 h. Droperidol 0.625 or 1.25 mg i.v. compared favorably with ondansetron 4 mg i.v. for the prevention of postoperative nausea and vomiting after ambulatory surgery.

Intravenous dolasetron for the prevention of postoperative nausea and vomiting after outpatient laparoscopic gynecologic surgery.

The newer 5-hydroxytryptamine type 3 (5-HT3) antagonists are sometimes considered for routine prophylaxis of postoperative nausea and vomiting (PONV) in high-risk patients. This multicenter, randomized, double-blind, placebo-controlled study compared the efficacy and safety of three single intravenous (IV) doses of dolasetron mesylate salt (12.5, 25, or 50 mg) for the prevention of PONV in 635 females undergoing outpatient laparoscopic gynecologic surgery. Antiemetic efficacy was evaluated over a 24-h postoperative period by recording the number and timing of emetic episodes; effects on nausea were evaluated by a visual analog scale (VAS). The proportion of complete responders (no emetic episodes and no escape medication in 24 h) was significantly higher with each dolasetron mesylate dose (> 50% for each dose; P < or = 0.0003) than with placebo (30.6%). Fewer patients given dolasetron required or requested escape antiemetic medication compared with placebo (P < 0.0003). Dolasetron-treated patients had significantly (P < 0.0357) lower median postdose maximum nausea VAS scores compared with placebo-treated patients. Patient satisfaction with dolasetron was high and, overall, was significantly (P = 0.0131) greater than that with placebo. Dolasetron was an effective and well tolerated preventive treatment for PONV resulting from laparoscopic gynecologic surgery.