Electron and ion temperature measurement with a new x-ray imaging crystal spectrometer on WEST.

A new x-ray imaging crystal spectrometer (XICS) has been installed, aligned, and used during experimental campaigns on the WEST tokamak. It has three interchangeable crystals for measuring the Ar XVII, Ar XVIII, and Fe XXV spectra, respectively. A patented rotating table holding the crystals is used to monitor the crystal facing the plasma remotely and without changing the position of the camera. Here, the focus is made on the Ar XVII spectrum, between 3.93 and 4.00 Å. The design of the diagnostic is presented, and a synthetic diagnostic, implemented with the Python library ToFu, is used to show the instrument's operational performance and limits. The instrument function exhibits the following two main features: a distortion for the Ar XVII spectrum, presumably due to the crystal manufacturing in two parts, and the measurement of three W spectral lines on the Ar XVI spectrum. Line of sight-integrated profiles of the electron and ion temperatures are thus extracted from the Ar XVII spectrum from two distinct spectral line ratios and from the Doppler broadening, respectively. The bremsstrahlung emission and the W line measurements are the two main limitations to compute the electron temperature. Tomographic inversions are also implemented with the library ToFu and used in order to obtain the local electron and ion temperature profiles, which are compared to other measurements from the WEST ECE (electron cyclotron emission) diagnostic. It is shown that both the XICS line-integrated and ECE Te measurements are in better agreement. Systematic differences are shown between the electron temperature profiles calculated from the two available line ratios.

Evaluation of alexithymia and depression in severe obese patients not affected by eating disorders.

OBJECTIVE: The main purpose of this study is to evaluate the different aspects of the construct of alexithymia in a group of severe obese patients not affected by eating disorders. Moreover, we tested if in the same patients there was a relationship between alexithymic traits and depressive symptoms. METHOD: Forty-nine severe obese patients were evaluated through the Toronto Alexithymia Scale (TAS-20) and the Beck Depression Inventory (BDI). The results were compared with those of a normal weight control group. RESULTS: Obese patients were less able than control subjects in recognizing and labeling their own emotions. This deficit was positively associated with depressive symptoms. CONCLUSIONS: The data suggest that severe obese patients have more difficulties in recognizing their emotions and have more depressive symptoms than control subjects have.

Acute renal failure in the patient undergoing cardiac operation. Prevalence, mortality rate, and main risk factors.

A total of 775 consecutive patients who survived the first 24 hours after cardiac operation were prospectively studied to assess the prevalence, mortality rate, and main risk factors for development of new acute renal failure. Normal renal function before operation (serum creatinine level less than 1.5 mg/dl) was registered in 734 (94.7%) patients. Of these, 111 (15.1%) showed a postoperative renal complication including 84 (11.4%) classified as renal dysfunction (serum creatinine level between 1.5 and 2.5 mg/dl) and 27 (3.7%) as acute renal failure (serum creatinine level higher than 2.5 mg/dl). The mortality rate was 0.8% in normal patients, 9.5% in patients with renal dysfunction, and 44.4% when acute renal failure developed (p < 0.0001). Indeed, the renal impairment proved to be an independent predictor of mortality (p < 0.001), along with the infective (p < 0.001), gastrointestinal (p < 0.001), and cardiovascular (p < 0.05) complications. Multivariate analysis identified the following variables as independent risk factors for postoperative renal impairment: use of intraaortic balloon pump (p < 0.0001), need for deep hypothermic circulatory arrest (p < 0.005), low-output syndrome (p < 0.005), advanced age (p < 0.005), need for emergency operation (p < 0.025), and low urinary output during cardiopulmonary bypass (p < 0.05). The 41 patients (5.3%) with preoperative renal failure showed a significantly higher morbidity and mortality rate than those without renal complications before operation. We conclude that in patients undergoing cardiac operation without preexisting renal dysfunction the likelihood of severe renal complications is reasonably low, but the associated mortality remains high. A prominent role in the development of postoperative acute renal failure must be recognized for preoperative, intraoperative, and postoperative hemodynamic factors, whereas cardiopulmonary bypass seems to be of lesser importance in this respect.

[Gastric pH changes during and after extracorporeal circulation. What is its clinical meaning?]. / Variazione del pH gastrico durante e dopo circolazione extracorporea. Quale significato clinico?

OBJECTIVE: To determine the relationship between gastric pH (pHm) and several other indices of blood perfusion in patients undergoing cardiopulmonary bypass (CPB). To evaluate the importance of pHm as a prognostic index for elective cardiac surgery. DESIGN: Prospectives study. SETTING: Cardiac surgery ICU of a Regional Hospital in Italy. PATIENTS: Nineteen patients were sequentially studies in a 4-month period. METHOD: Before anesthetic induction, a pH probe incorporated in the tip of a nasogastric tube (GrapHprobe SH, GrapHometer, Zinetics Medical, USA) was inserted in the stomach. Results, collected during the CPB and in the postoperative period until 1 hour after extubation, were compared to the peripheral tissue perfusion and oxygenation data (transcutaneous: PtcO2), hemodynamic variations (Swan-Ganz catheter), pharyngeal temperature, and blood gases. RESULTS: No significant variations of pHm were reported during the study. Significant relations were found only after surgery between pHm and PaO2 (p < 0.001), hemoglobin (p < 0.001), and blood pH (p < 0.05). No statistical correlations were reported between pHm and hemodynamic variations. CONCLUSIONS: Although a significant variation of peripheral and pulmonary vascular resistance and transcutaneous oxygenation was reported throughout the study, no correlations were found to pHm. At present it is not possible to confirm the importance of pHm as a prognostic index for elective cardiac patients, even though it is necessary to examine whether the additional data of pHm variation could be considered a true marker of visceral perfusion.

[Prospective evaluation of the role of abdominal echocardiography in the treatment of seriously traumatized patients]. / Valutazione prospettica del ruolo dell'ecografia addominale nel trattamento del grave traumatizzato.

The reliability of abdominal ultrasonography (US) in a clinical algorithm for emergency management of blunt trauma was evaluated prospectively. From November 1, 1987 to December 31, 1988, of 111 severe trauma victims admitted to our ICU, 63 were screened according to protocol by US for peritoneal fluid and splenic and/or hepatic injuries. The mean age was 49.6 years. The mean ISS and APACHE II Score was 26.9 and 13.7 respectively. The sensitivity of US for detection of peritoneal fluid was 95%, specificity 97.6%, positive predictive value 95%, negative predictive value 97.6% with a prevalence of 31.7%. For hepatic and splenic injuries instead the results were not as good as for abdominal fluid. Twelve patients underwent laparotomy and 6 with abdominal injuries were successfully treated nonoperatively with serial US examinations. Overall mortality was 12 (19%). No patients died for delayed or missed diagnosis of abdominal injury.

Equilibrium and kinetics of the reaction of Aplysia myoglobin with azide.

The present paper reports a study on the equilibria and kinetics of the acid-alkaline transition and the azide binding reaction by ferric Aplysia myoglobin. A single completely reversible spectrophotometric titration curve is found over the pH range from similar to 5 to similar to 9, with an apparent pK equals to 7.5 for the acid-alkaline transition. The kinetics of the process, followed by the temperature-jump method, gives, at pH values close to the pK of the transition, one single, well-resolved, relaxation independent of protein concentration and of type of buffer used. The pattern accords to a simple pH dependent reaction, in buffered medium, between the two forms of the protein. The results of the azide binding reaction show that the process conforms to simple equilibrium as expected for a single site protein. The méasured association constant is reported as a function of pH. The kinetics of the reaction of Aplysia metMb with N3- minus shows, on the other hand, a complex behavior. The relaxation pattern is found to strongly depend on pH and ligand concentration in such a way to suggest a linkage between ligand binding and acid-alkaline transition. The system is discussed on the basis of two simplifying conditions, i.e., at low and higher pH with respect to the pK of the acid-alkaline transition. At acid pH the reaction corresponds to a single bimolecular process as expected for a simple binding reaction; at alkaline pH, the dependence of relaxation time on ligand concentration implies the existence of a rate-limiting monomolecular step. On the basis of a reaction scheme implying that binding of the ligand can only occur through the acid (aquomet) form of the protein via the displacement of the water molecule, the experimental data are quantitatively accounted for.