HIGHLY ENRICHED URANIUM BLEND DOWN PROGRAM AT THE SAVANNAH RIVER SITE PRESENT AND FUTURE

The Department of Energy (DOE) and Tennessee Valley Authority (TVA) entered into an Interagency Agreement to transfer approximately 40 metric tons of highly enriched uranium (HEU) to TVA for conversion to fuel for the Browns Ferry Nuclear Power Plant. Savannah River Site (SRS) inventories included a significant amount of this material, which resulted from processing spent fuel and surplus materials. The HEU is blended with natural uranium (NU) to low enriched uranium (LEU) with a 4.95% 235U isotopic content and shipped as solution to the TVA vendor. The HEU Blend Down Project provided the upgrades needed to achieve the product throughput and purity required and provided loading facilities. The first blending to low enriched uranium (LEU) took place in March 2003 with the initial shipment to the TVA vendor in July 2003. The SRS Shipments have continued on a regular schedule without any major issues for the past 5 years and are due to complete in September 2008. The HEU Blend program is now looking to continue its success by dispositioning an additional approximately 21 MTU of HEU material as part of the SRS Enriched Uranium Disposition Project

Non-linearity and related features of Makyoh (magic-mirror) imaging

Non-linearity in Makyoh (magic-mirror) imaging is analyzed using a geometrical optical approach. The sources of non-linearity are identified as (1) a topological mapping of the imaged surface due to surface gradients, (2) the hyperbolic-like dependence of the image intensity on the local curvatures, and (3) the quadratic dependence of the intensity due to local Gaussian surface curvatures. Criteria for an approximate linear imaging are given and the relevance to Makyoh-topography image evaluation is discussed

Priapismul iatrogen. Recomandări practice de tratament

Summary Results of examining and treatment of 19 patients suffering from acute Priapism and was evaluated. Adequate therapy considerably reduce surgery rate and increase erectile function recuperation. We consider the serious medical error is not performing preventive test before intracavernose injection. Introducere. Priapismul este erecţia prelungită, dureroasă neînsoţită de libido sau de satisfacţie sexuală. Se observă, în special, la bărbaţii sexual activi cu vârsta de la 20 la 50 ani. Incidenţa priapismului este relativ scăzută (sub 0,4%). Administarea intracavernoasă a preparatelor farmacologice pentru tratamentul disfuncţiei erectile, adeseori nejustificată şi necontrolată, a dus la creşterea bruscă a incidenţei. Scopul lucrării. Analiza cazurilor de priapism iatrogen şi stabilirea unor metode eficiente de tratament şi de profilaxie. Material şi metodă. În perioada 1999-2005 sub observaţia noastră s-au aflat 19 pacienţi cu priapism acut. Dintre aceştea, 12 (63%) au fost cu priapism iatrogen. La 2 pacienţi priapismul a apărut în urma testării farmacologice a erecţiei cu papaverină, efectuată în clinica noastră, iar la 10 - în urma tratamentului disfuncţiei erectile prin injectare intracavernoasă de papaverină, Caverject, sau a unor substanţe necunoscute, administrate în alte instituţii. Vârsta pacienţilor a variat de la 21 (!) la 49 ani. Perioada de timp de la apariţia priapismului până la adresare a fost de la 2 ore (în cazul testării funcţiei erectile) la 96 (!) ore. Rezultate. În urma tratamentului conservator prin adminisrarea intracavernoasă de adrenomimetice, aspiraţia coprilor cavernoşi, perfuzii cu Sol.Heparină, am reuşit eradicarea priapismului la 7 pacienţi, inclusiv în condiţii de ambulator. În 5 cazuri, la pacienţii cu o adresabilitate de peste 24 ore, am recurs la tratament chirurgical. Am efectuat fistula spongiocavernosă la 4 pacienţi, iar anastomoza spongicavernoasă la 1 pacient. Nu am avut complicaţii intraoperatorii sau recidivă postoperatorie a priapismului. Discuţii şi concluzii. Conform schimbărilor hemodinamice în corpii cavernoşi deosebim priapism acut de stază şi priapism acut datorat creşterii aportului arterial. În prima situaţie, în circa 24 ore se produce necroza ţesutului cavernos, spre deosebire de a doua, când priapismul poate continua câteva zile. Tipul priapismului iatrogen nu este elucidat pe deplin, totuşi, deja peste 4 ore de la debut, în teşutul cavernos se produc fenomene evidente de hipoxie, care peste 12 ore duc la schimbări ireversibile. Prin urmare, intervalul maxim de timp admis înaintea detumiscenţei active va varia între 4 şi 12 ore. Dacă diagnosticul este stabilit până în acest interval, prezenţa erecţiei dureroase impune administrarea intracavernoasă de substanţe adrenomimetice. Din experienţa noastră am observat că efectul optim aparţine Fenilefrinei (Mezaton) în doze de la 1 la 5mg, în administrare lentă, sub controlul T/A. În caz de ineficienţă, la interval de 0,5-1 ore, se readministrează. În priapismul cu o durată de peste 4 ore, în prima etapă se va efectua puncţia aspirativă din coprii cavernoşi a circa 50-60 ml sânge, în scopul scăderii presiunii intracavernoase, apoi, prin acelaşi ac, se administrează soluţia adrenomimetică. La un interval de peste reduce rata intervenţiilor chirugicale şi restabilirea ulterioară a funcţiei erectile. Tratamentul conservator neadecvat, în special prin măsuri de ordin general (sedative, tranchilizante, comprese reci, antispastice) doar agravează decurgerea maladiei şi temporizează efectuarea tratamentului corect, având repercusiuni grave asupra funcţiei sexuale ulterioare. În acelaşi timp administrarea intracavernoasă a substanţelor farmacologcie fără o testare prealabilă a erecţiei şi a dozelor optime constituie o gravă eroare medicală

Isomers production in 238U photofission

The fission process induced by gamma quanta up to 25 MeV energy on 238U was analyzed. Experimental observables as cross sections, fragments mass distribution yields of some nuclides of interest and average prompt neutrons multiplicity characterizing 238U photofission process were theoretically evaluated using TALYS 1.9 software. Theoretical evaluations of isomer ratios using Talys supplied by author’s own code as well as experimental isomer ratios obtained at MT - 25 Microtron are presented

Acute pyelonephritis in urological practice - etiology, diagnosis and treatment

Catedra Urologie şi Nefrologie Chirurgicală, USMF„Nicolae Testemiţanu", Secţia Urologie, IMSP SCR, Al VI-lea Congres de Urologie, Dializă şi Transplant Renal din Republica Moldova cu participare internaţională (21-23 octombrie 2015)Rezumat Infecţia tractului urinar (ITU) reprezintă una dintre cele mai frecvente infecţii bacteriene în ţările industrializate, fiind o infecţie bacteriană nespecifică, ce poate fi cauzată de către o varietate de agenţi patogeni.Actualmente diagnosticul acestei patologii s-a îmbunătăţit graţie prezenţei metodelor moderne de diagnostic.ln lucrare sunt expuse rezultatele studiului literaturii de specialitate referitoare la diagnostic, evoluţie şi tratament a Pielonefritei acute şi Pielonefritei acute la gravide.Summary Urinary tract infection is one of the most frequent bacterial infection in the development countries.Crrently,the diagnosis of this pathology was significantly improved due to the varios methods of diagnosis and treatment.This scientific work analyses data available in specialized literature,evolution and treatment of acute pyelonephritis and acute pyelonephritis in pregnancy

Our experience in acute pyelonephritis treatment in pregnancy

Secţia Urologie IMSP Spitalul Clinic Republican, Catedra Urologie şi Nefrologie Chirurgicală USMF „N.Testemiţanu”, Al V-lea Congres de Urologie, Dializă şi Transplant Renal din Republica Moldova cu participare internaţională (1-13 iunie 2011)Summary. It is known that during the pregnant morbidity the extragenital pathology is ranked on the first place. Although the pregnancy is a physiologic phenomenon, the vulnerability of the organism in pregnancy is increasing, especially the cardiovascular system that should ensure a complex sanguine circuit – placenta, and of the kidneys that should detoxify a supplemental weight of fetus. The renal pathology in pregnancy occupies the second rank between extrauterine pathologies. Under the influence of some factors, the increasing of PNA in pregnant patients could be observed. Pyelonephritis in pregnancy is a complicated condition with no clear evolution and not very good prognosis for both - the mother and fetus. 49 pregnant patients were evaluated with PNA. In all cases, a treatment was adjusted with favorable results, that included ureteral catheterization and insertion of autostatic stent like JJ stent. The PNA treatment in pregnancy implies the JJ stent insertion, that has an essential role in decompression of renal pelvis and have minimal risk of complications. This contributes to reduction of treatment duration with antibiotics

Optimality of mutation and selection in germinal centers

The population dynamics theory of B cells in a typical germinal center could play an important role in revealing how affinity maturation is achieved. However, the existing models encountered some conflicts with experiments. To resolve these conflicts, we present a coarse-grained model to calculate the B cell population development in affinity maturation, which allows a comprehensive analysis of its parameter space to look for optimal values of mutation rate, selection strength, and initial antibody-antigen binding level that maximize the affinity improvement. With these optimized parameters, the model is compatible with the experimental observations such as the ~100-fold affinity improvements, the number of mutations, the hypermutation rate, and the "all or none" phenomenon. Moreover, we study the reasons behind the optimal parameters. The optimal mutation rate, in agreement with the hypermutation rate in vivo, results from a tradeoff between accumulating enough beneficial mutations and avoiding too many deleterious or lethal mutations. The optimal selection strength evolves as a balance between the need for affinity improvement and the requirement to pass the population bottleneck. These findings point to the conclusion that germinal centers have been optimized by evolution to generate strong affinity antibodies effectively and rapidly. In addition, we study the enhancement of affinity improvement due to B cell migration between germinal centers. These results could enhance our understandings to the functions of germinal centers.Comment: 5 figures in main text, and 4 figures in Supplementary Informatio

Characterization of the n-TOF EAR-2 neutron beam

The experimental area 2 (EAR-2) at CERNs neutron time-of-flight facility (n-TOF), which is operational since 2014, is designed and built as a short-distance complement to the experimental area 1 (EAR-1). The Parallel Plate Avalanche Counter (PPAC) monitor experiment was performed to characterize the beam prole and the shape of the neutron 'ux at EAR-2. The prompt γ-flash which is used for calibrating the time-of-flight at EAR-1 is not seen by PPAC at EAR-2, shedding light on the physical origin of this γ-flash