Presolar corundum and spinel in ordinary chondrites: origins from AGB stars and a supernova.

On the basis of anomalous isotopic compositions of oxygen and magnesium, 14 oxide grains from two primitive meteorites (Bishunpur and Semarkona) have been identified as circumstellar condensates. One corundum grain has a high 18O/16O ratio and isotopic compositions of magnesium, calcium, and titanium that are compatible with a formation in ejecta of a type II supernova that was about 15 times the mass of the sun. The other grains have oxygen, magnesium, and titanium compositions that are consistent with a formation around asymptotic giant branch (AGB) stars with a range of mass and initial composition. The large range of aluminum/magnesium in circumstellar corundum and spinel is considered to reflect various stages of back-reaction between condensed corundum and gaseous magnesium in cooling stellar ejecta.

Intravascular stenting as a definitive treatment of spontaneous carotid artery dissection.

We describe successful treatment with intravascular stenting of a patient with spontaneous right carotid artery dissection. This case report demonstrates the potential use of stents for treating symptomatic carotid artery dissection.

Left ventricular filling patterns in aortic stenosis in patients older than 65 years of age.

Left ventricular (LV) filling patterns in 26 elderly (mean age 81 years) patients with severe aortic stenosis (AS) were evaluated using pulsed-wave Doppler echocardiography. Parameters of LV filling, including the ratio of the peak atrial velocity to the peak early diastolic velocity (A/E ratio) and the percent contribution of active atrial filling to total LV filling (%A), of these patients with AS (group I) were compared with 2 groups presumed to have abnormal LV filling: elderly patients (group II) and hypertensives with increased LV mass (group III), as well as with normal volunteers (group IV). The patients with AS had a broad range of LV inflow velocity patterns (A/E = 0.91 +/- 0.56, range 0.20 to 1.91; %A = 34.3 +/- 16.4, range 3.0 to 65), as compared with the consistently low A/E ratio (0.48 +/- 0.13) and %A (25 +/- 7) in the normal volunteers and the high A/E ratio and %A in the elderly (A/E = 1.48 +/- 0.28, %A = 49 +/- 11) and hypertensive (A/E = 1.41 +/- 0.32, %A = 49 +/- 8) groups. When comparing the data obtained by Doppler with hemodynamics at catheterization, the patients with AS and a high A/E ratio (A/E ratio greater than 1, n = 11) had lower LV mid-diastolic pressures (7 vs 18 mm Hg, p less than 0.001), lower pulmonary artery systolic pressures (33 vs 49 mm Hg, p less than 0.05) and less symptomatic heart failure than those patients with AS and a low A/E ratio (A/E less than 1). The aortic valve area was similar in these 2 subgroups (0.40 vs 0.37 cm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of fish oil supplements in preventing clinical evidence of restenosis after percutaneous transluminal coronary angioplasty.

This study assesses the effect of dietary supplements with high dose omega-3 fatty acid (N3FA) on the frequency of clinical restenosis during the 6 months after successful percutaneous transluminal coronary angioplasty (PTCA). One hundred ninety-four patients (214 significant coronary narrowings) were randomized after successful PTCA to receive conventional medical therapy or to an identical regimen supplemented by high dose N3FA (4.5 g/day). Enrollment required angina pectoris and successful dilatation of all significant coronary narrowings. The subjects were randomly assigned to either no N3FA (control, n = 99) or N3FA supplementation (n = 95). After a 1-week trial period, 11 (group 2) declined further treatment because of side effects. The remaining 84 subjects (group 1) continued N3FA throughout the 6-month period. Monthly clinical follow-up was obtained in all patients. Ninety-two percent of patients had cardiac testing for evaluation of recurrent ischemia. Except for a greater percentage of women in the group refusing N3FA supplementation (group 2), the 3 groups were similar in demographic data, medical history, dietary habits, history of previous PTCA and angiographic characteristics. Of the 194 subjects, 56 had clinical restenosis (45 by cardiac catheterization, 8 by exercise testing and 3 by symptoms alone [refused further clinical testing]). Reocclusion rates were: group 1 19%, group 2 46%, and control 35%. Analysis both in accordance with the principle of intention to treat and for subjects who actually received N3FA revealed a significant effect of N3FA on preventing clinical restenosis (p less than 0.04 and p = 0.008, respectively). These data suggest that high dose N3FA supplements reduce the clinical restenosis rate after successful PTCA.

Spontaneous spinal epidural hematoma causing cord compression after streptokinase and heparin therapy for acute coronary artery occlusion.

We have reported a case of spinal epidural hematoma with cord compression in a 49-year-old man treated with short-term streptokinase and continuous heparin infusion. The sudden onset of back pain with subsequent neurologic deficits in a patient treated with fibrinolytic therapy alone or in combination with an anticoagulant should prompt an evaluation for spinal epidural hematoma with associated cord compression. The risk of combined fibrinolytic and anticoagulant therapy is not clear and warrants further evaluation.

Neutron capture on (180)Ta(m): clue for an s-process origin of nature's rarest isotope.

The neutron capture cross section of (180)Ta(m) has been measured in the keV range, yielding a stellar average of 1465+/-100 mb at kT = 30 keV. Though the sample contained only 6.7 mg (180)Ta(m) (at an enrichment of 5.5%), the few capture events could be separated from much larger backgrounds by a unique combination of high efficiency, good energy resolution, and high granularity of the Karlsruhe 4 pi BaF(2) detector. A detailed s-process analysis based on this first experimental value indicates that (180)Ta(m) is predominantly of s-process origin.

Neutron capture cross section measurement of 151Sm at the CERN neutron time of flight facility (n_TOF).

The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross section is of importance for characterizing neutron capture nucleosynthesis in asymptotic giant branch stars. At a thermal energy of kT=30 keV the Maxwellian averaged cross section of this unstable isotope (t(1/2)=93 yr) was determined to be 3100+/-160 mb, significantly larger than theoretical predictions.