Speciation of radionuclides in colloidal matter of underground waters taken from observation wells in the zone of impact of Lake Karachai

The strength of actinide bonding with colloidal matter of groundwaters from the Lake Karachai contamination area was studied by selective leaching. An α-track analysis showed that the microdistribution of α-emitting radionuclides in the colloidal matter is uniform. Analysis of fission tracks confirms the presence of ²³⁹Pu and ²⁴¹Am in the colloidal material. In the colloidal matter of groundwaters taken from three wells and differing in the chemical composition, radionuclides occur in forms differing in the solubility. U and Np in the colloidal material are associated only with readily soluble and mobile groups of compounds and are not detected in the difficultly soluble residue. Pu and Am, on the contrary, occur in the colloidal material of groundwaters mainly in difficultly soluble forms. Am is bound to a greater extent with surface organometallic complexes. Pu is detected mainly in the fraction of amorphous oxides.     

Self-blocking of dislocations in intermetallic compound Ni<Subscript>3</Subscript>Ge: Cubic slip

Self-blocking of dislocations belonging to the cube plane has been detected in the intermetallic compound Ni₃Ge. The nature of cubic slip has been clarified. The experiments included deformation at a temperature above T _max (the temperature of the yield-stress peak) and subsequent heating without stress. In addition, changes in the dislocation structure upon slow cooling from the temperature of the preliminary deformation have been investigated; in doing so, self-blocking of dislocations has been revealed for the first time. Based on the totality of experimental data, a conclusion has been made on the two-valley potential relief for a dislocation motion in the cube plane. It is the difference in the depths between the Peierls valley (a diffuse core in the cube plane) and the deepest valley (a superpartial dislocation split in the octahedron plane) that provides for the driving force of self-blocking in the absence of an external stress. Different aspects of cubic slip have been considered: the disappearance of cubic slip at T < T _max and, correspondingly, the nonobservation of an anomalous behavior of the yield stress, as well as the disappearance of octahedral slip at T > T _max.     

核电厂环保应急计算机系统的设计

以核电厂环保与应急计算机系统为例,建立了一个具有实时监测数据的收集、评价与可靠传输、日常办公事务处理等主要功能的计算机系统。介绍了该系统的架构、设计原理、思想与方法,给出了相应的总体设计方案与应用软件功能。该系统亦适用于同类电厂。     

Solid-State Reactivity of the ZnO-xMn2O3 System During Heat Treatment

Using X-ray, infrared, and electron paramagnetic resonance methods, the reactivity of ZnO+ x Mn₂O₃ systems during heat treatment was studied. Results showed that the solubility of manganese (Mn) in zinc oxide (ZnO) is lower than 3% and that reaction diffusion occurs. Reaction processes that take place in this system promote disintegration of Mn₂O₃ particles into microfragments and causes them to move along the surface of the ZnO particles (solid-state reactive wetting process).     

A rare and little known variant of hypospadias

Hypospadia is a congenital defect presenting as different variants of dysplasia of the distal urethra with ectopy of the urethral external orifice and distortion of the penis. A variant of hypospadia not yet described in Russian medical literature was observed in a newborn boy. He had normal penis and scrotum, but on the under-side of the penis there was a site of thin skin protruding as a resonance bag in urination. At the site of the thin skin the back urethral wall was absent with a cavity covered by the thin skin. In urination urine filled the cavity blowing up the skin above it to the form of the resonance bag. This variant of hypospadia was designated as segmental urethral hypoplasia.     

A prospective 12-year study of subsyndromal and syndromal depressive symptoms in unipolar major depressive disorders

BACKGROUND: Investigations of unipolar major depressive disorder (MDD) have focused primarily on major depressive episode remission/recovery and relapse/recurrence. This is the first prospective, naturalistic, long-term study of the weekly symptomatic course of MDD. METHODS: The weekly depressive symptoms of 431 patients with MDD seeking treatment at 5 academic centers were divided into 4 levels of severity: (1) depressive symptoms at the threshold for MDD; (2) depressive symptoms at the threshold for minor depressive or dysthymic disorder (MinD); (3) subsyndromal or subthreshold depressive symptoms (SSDs), below the thresholds for MinD and MDD; and (4) no depressive symptoms. The percentage of weeks at each level, number of changes in symptom level, and medication status were analyzed overall and for 3 subgroups defined by mood disorder history. RESULTS: Patients were symptomatically ill in 59% of weeks. Symptom levels changed frequently (1.8/y), and 9 of 10 patients spent weeks at 3 or 4 different levels during follow-up. The MinD (27%) and SSD (17%) symptom levels were more common than the MDD (15%) symptom level. Patients with double depression and recurrent depression had more chronic symptoms than patients with their first lifetime major depressive episode (72% and 65%, respectively, vs 46% of follow-up weeks). CONCLUSION: The long-term weekly course of unipolar MDD is dominated by prolonged symptomatic chronicity. Combined MinD and SSD level symptoms were about 3 times more common (43%) than MDD level symptoms (15%). The symptomatic course is dynamic and changeable, and MDD, MinD, and SSD symptom levels commonly alternate over time in the same patients as a symptomatic continuum of illness activity of a single clinical disease.     

The laboratory diagnosis of spring-summer infections in Yekaterinburg in the epidemic season for tick-borne encephalitis

The authors propose a comprehensive approach to laboratory diagnosis of seasonal transmissible infections, based on modern methods permitting etiological deciphering of disease. A universal diagnostic algorithm notably accelerated the laboratory diagnosis due to cutting the period between collection of material from a patient and consecutive screening for antibodies to agents of tick-borne encephalitis, Lyme disease, and California encephalitis.     

Routine intraoperative laparoscopic cholangiography

BACKGROUND: Whether intraoperative laparoscopic cholangiography should be routine is debatable. METHODS: We reviewed the cholangiography experience in 669 consecutive laparoscopic cholecystectomies. RESULTS: Mean age of the patients was 39 years, 78% were female, and 29% had acute cholecystitis. Cholecystectomy was completed laparoscopically in 606 (91%). Laparoscopic cholangiography was completed in 562 (93%) and 348 (62%) were routine (no preoperative indication). The mean operating time in 1996 was 61 minutes. Out of the 348 routine cholangiograms, 17 demonstrated evidence of unsuspected choledocholithiasis. Five patients had choledocholithiasis documented by laparoscopic common bile duct exploration and/or endoscopic retrograde cholangiopancreatography. Two patients had normal postoperative cholangiopancreatography. One of 10 patients managed expectantly was readmitted postoperatively with obstructive jaundice. In 4 patients, routine cholangiography revealed unexpected anatomy, and in 2, this prevented misidentification and transection of the common bile duct. CONCLUSION: Laparoscopic cholangiography is safe, quick, detects unsuspected choledocholithiasis, and can prevent common bile duct transection. It should be routine.