Measurement of the first ionization potential of astatine by laser ionization spectroscopy.

The radioactive element astatine exists only in trace amounts in nature. Its properties can therefore only be explored by study of the minute quantities of artificially produced isotopes or by performing theoretical calculations. One of the most important properties influencing the chemical behaviour is the energy required to remove one electron from the valence shell, referred to as the ionization potential. Here we use laser spectroscopy to probe the optical spectrum of astatine near the ionization threshold. The observed series of Rydberg states enabled the first determination of the ionization potential of the astatine atom, 9.31751(8) eV. New ab initio calculations are performed to support the experimental result. The measured value serves as a benchmark for quantum chemistry calculations of the properties of astatine as well as for the theoretical prediction of the ionization potential of superheavy element 117, the heaviest homologue of astatine.

Magnetic dipole moment of (57,59)Cu measured by in-gas-cell laser spectroscopy.

For the first time, in-gas-cell laser spectroscopy study of the (57,59,63,65)Cu isotopes has been performed using the 244.164 nm optical transition from the atomic ground state of copper. The nuclear magnetic dipole moments for (57,59,65)Cu relative to that of (63)Cu have been extracted. The new value for (57)Cu of mu((57)Cu) = +2.582(7)mu(N) is in strong disagreement with the previous literature value but in good agreement with recent theoretical and systematic predictions.

Interplay between single-particle and collective effects in the odd-A Cu isotopes beyond N=40.

Collective properties of the low-lying levels in the odd-A 67-73Cu were investigated by Coulomb excitation with radioactive beams. The beams were produced at ISOLDE and postaccelerated by REX-ISOLDE up to 2.99 MeV/u. In 67,69Cu, low-lying 1/2(-), 5/2(-), and 7/2(-) states were populated. In 71,73Cu, besides the known transitions deexciting the single-particle-like 5/2(-) and core-coupled 7/2(-) levels, gamma rays of 454 and 135 keV, respectively, were observed for the first time. Based on a reanalysis of beta-decay work and comparison with the systematics, a spin 1/2(-) is suggested for these excited states. Three B(E2) values were determined in each of the four isotopes. The results indicate a significant change in the structure of the odd-A Cu isotopes beyond N=40 where single-particle-like and collective levels are suggested to coexist at very low excitation energies.

Characterization of rat thrombin-activatable fibrinolysis inhibitor (TAFI)--a comparative study assessing the biological equivalence of rat, murine and human TAFI.

BACKGROUND AND OBJECTIVES: Activated thrombin-activatable fibrinolysis inhibitor (TAFIa) attenuates fibrinolysis. Although rat models to study the role of TAFI are available, the biochemical properties of rat TAFI are not well investigated and immunologic tools are lacking. Therefore, we have characterized recombinant rat TAFI-6His and compared its properties with those of human TAFI as well as of murine TAFI-V5-6His. METHODS AND RESULTS: TAFI from all three species is activatable by the thrombin-thrombomodulin complex, generating a highly unstable protein (TAFIa). Half-lives at 37 degrees C are 8.5+/-0.6 min, 3.4+/-0.4 min and 2.2+/-0.2 min for human, rat and murine TAFIa, respectively. The 50% clot lysis times are 6+/-1 min for TAFI-depleted rat plasma and 137+/-34 min, 62+/-9 min and 50+/-8 min when TAFI-depleted rat plasma is supplemented with 0.02 U of human, rat or murine TAFIa, respectively, which correlates with their half-lives. Upon incubation with the thrombin-thrombomodulin complex, the 36-kDa fragment of rat and murine TAFI is not cleaved into 25-kDa and 11-kDa fragments. Upon incubation of rat TAFI and murine TAFI with plasmin, a 32-kDa fragment is formed due to cleavage at Arg147, in contrast to the formation of a 36-kDa fragment for human TAFI. Concomitantly, activity levels upon plasmin incubation are drastically reduced for rat and murine TAFI. CONCLUSIONS: Recombinant human, rat and murine TAFI have similar but not identical biochemical characteristics, suggesting a similar role during fibrinolysis in vivo.

Continuous venovenous hemofiltration improves cardiac performance by mechanisms other than tumor necrosis factor-alpha attenuation during endotoxic shock.

OBJECTIVE: To assess the effects of continuous venovenous hemofiltration (CWH) on global and regional hemodynamics, plasma lactate, and tumor necrosis factor-oa (TNF-a) levels during endotoxic shock in dogs. METHODS: Thirty pentobarbital-anesthetized and mechanically ventilated dogs were divided into six groups of five dogs each. Group 1 served as a control, undergoing CWH at 3 Uhr without endotoxin. Group 2 served as the endotoxin-alone time-matching group. Group 3 received CWH 1 hr after endotoxin at 3 Uhr for 270 mins. Group 4 received CWH 1 hr after endotoxin at 3 Uhr for 150 mins and at 6 Uhr for an additional 120 mins. Group 5 and group 6 received the ultrafiltrate from group 1 and group 3, respectively. MEASUREMENTS AND MAIN RESULTS: Three hours after endotoxin challenge, dogs treated with CWH at 3 Uhr had a higher cardiac output (4.9 + 0.6 vs. 2.9 + 0.6 Umin; p < .05) and stroke volume (35 + 7 vs. 20 + 4 mL; p < .05) and a lower pulmonary vascular resistance (116 26 vs. 331 + 126 dyne-sec/cm5; p < .05) than the endotoxin-alone group. Five hours after endotoxin, dogs treated with CWH at 6 Uhr also had higher hepatic (464 + 164 vs. 126 + 75 mUmin; p < .05) and femoral (95 + 46 vs. 30 + 34 mL/min; p < .05) blood flow. Moreover, dogs treated with CWH at 6 Uhr had higher mean arterial blood pressure (84 + 24 vs. 40 + 15 mm Hg; p < .05) and left ventricular stroke work index (1.1 + 0.6 vs. 0.2 + 0.2 g/kg; p < .05) than the endotoxin-alone group. Plasma lactate levels were lower in the CWH group at 6 Uhr (2.7 + 1.1 mmol/L) than in the endotoxin-alone group (4.4 + 0.6 mmol/L; p < .05). Plasma TNF-ao levels were unaffected, and only minor amounts of TNF-o were found in the ultrafiltrate. CONCLUSION: In this acute endotoxic shock model, CWH at 3 Uhr improved cardiac performance and decreased pulmonary vasoconstriction. Moreover, CWH at 6 LUhr also increased arterial blood pressure and left ventricular stroke work, increased hepatic and femoral arterial blood flow, and decreased blood lactate levels. These effects were not attributable to TNF-alpha removal.

A profile of European ICU nursing.

OBJECTIVE: To evaluate major similarities and major differences between Western European countries in intensive care unit (ICU) nurse staffing, education, training, responsibilities, and initiative. DESIGN: A questionnaire was sent to Western European doctor members of the European Society of Intensive Care Medicine, to be passed on to the nurse-in-charge of their ICU. RESULTS: 156 completed questionnaires were analyzed: 49% were from university hospitals, 26% from university-affiliated hospitals, and 25% from community hospitals; 42% of the hospitals had more than 700 beds, 67% of the ICUs had between 6 and 12 beds, and 54% were mixed medical-surgical units. Among British units, 79% had more than three full-time nursing equivalents (FTE) per ICU bed, while in Sweden 75% of units had less than two FTE/ICU bed. University hospitals had more nursing staff per bed than community hospitals. As regards training, 33% of nurses followed a training course before starting work on the ICU and 64% after starting on the unit, and 85% had easy access to continuing education, particularly in the university hospitals. In an emergency, more than 70% of nurses regularly initiated oxygen administration, mask ventilation, or cardiac massage. In Sweden 100% of nurses and in Switzerland 91% of nurses regularly inserted peripheral intravenous catheters, but only 7% of German nurses did. No German nurses and only 12% of British nurses regularly performed arterial puncture, but in Sweden 75% of nurses regularly did. CONCLUSION: Even though the number of participants were limited, our questionnaire revealed variations in nurse staffing patterns among European countries and in their systems of training and education. Nurse autonomy also varies widely between countries.

[Reaction of carbodiimide for the introduction of p-bis(2-chloroethyl)amino-L-phenylalanine to lysozyme]. / Réaction à la carbodiimide visant l'introduction de la p-bis-(2-chloroéthyl)amino-L-phénylalanine sur le lysozyme.

In the synthesis of new prodrugs with inhibitoring action of tumour growth, a new nitrogen mustard derivative was obtained, proceeding of the coupling between an egg-white lysozyme with an antitumor amine nucleophile, the methyl ester of p-bis-(2-chloroethyl)amino-L-phenylalanine (Melphalan), catalyzed by 1-ethyl-3-[3-(dimethylamino)propyl] carbodiimide (EDC), at pH 5.0 and room temperature. In that case, the mechanism for the modification isn't selective of Asp101 in lysozyme. As in cases of histamine and D-glucosamine [3], it is evident that Melphalan is one type of amine who doesn't cause a selective modification of Asp101 but causes somewhat random reaction, because Asp101 is modified followed by modifications of other carboxyls. In this case, we suggest that the amine (Melphalan) may also bind to the substrate binding site in competition with EDC. With this type of amine, enzyme-nucleophile interactions predominate, and the selective activation of Asp101 by EDC is reduced to lead a more random reaction.