Is it possible to differentiate between choledochal cyst and congenital biliary atresia (type I cyst) by antenatal ultrasonography?

Both choledochal cyst and congenital biliary atresia (type I cyst) may share the same ultrasonographic pattern. We report 2 cases which were shown to have cystic structures on the upper abdomen by antenatal ultrasonography. The size of the choledochal cyst found at 24 weeks' gestation increased steadily as gestational age advanced. But the size of the cyst in congenital biliary atresia found at 29 weeks' gestation remained unchanged throughout the remaining pregnancy. Cyst enlargement, therefore, may suggest the possibility of a choledochal cyst.     

Extracorporeal shock-wave lithotripsy in patients with manifestations of urinary tract infection

The urinary tract infection is very frequent, especially if calculosis of the urinary tract is present. Urinary infection is widespread, and it appears during the year. The people of all ages and both sexes are affected by urinary infection. In the last few years a reliable progress in the understanding and management of urinary tract infection is achieved. Numerous articles published in professional journals are a good proof of it. The urinary tract infection is frequent and is responsible for the use of large quantities of antibiotics which provoke great costs and make other problems. The role of laboratory tests in the diagnosis of infection is predominant. The clinician is completely dependent on his collegue, a bacteriologist, with regard to the results of urine culture. It is known that microorganisms grow better if they have good nourishment. Infections of the urinary tract were always a significant problem. However, over the last few decades, they became, according to some authors, the most frequent bacterial infection in humans, requiring the frequent administration of immunosuppressive agents, corticosteroids and cytostatics; and at the same time a great number of elder people and chronic patients with reduced immunity are involved. Taking into account that significant and insignificant infections of the urinary tract are frequent in nephropathology, particularly in renal and canalicular calculosis, the aim of the study was to point to extracorporeal shock wave lithotripsy without risk of impairment of already existing infections with and without administration of antibiotic and uroantiseptic agents for prophylactic purposes. A group of 5,078 patients with calculosis of the urinary tract was studied. Extracorporeal shock wave lithotripsy was performed in all patients by Siemens lithotriptor Lithostar (Germany). In patients with calculosis of the urinary tract subjected to extracorporeal lithotripsy bacteriuria was regularly followed. A group of 1,836 (36 percent) patients with urinary tract obstruction and 3,242 (64 percent) patients without urinary tract obstruction were treated (Table 1). In 895 (18 percent) patients with urinary tract obstruction infection was serious. In 321 (6 percent) patients without urinary tract infection, serious urinary tract infection was detected (Table 2). The most frequent causes of urinary tract infection are presented in Table 3. Table 4 shows a review of patients to whom antibiotic therapy, prior to extracorporeal lithotripsy, was prescribed. Infection of the urinary tract is responsible for great morbidity. The treatment of any type of urinary tract infection must include the examination of the effect of antibiotic agents. During the treatment of urinary tract infection with calculosis resistant microorganisms are also developed because of repeated administration of antibiotics to patients in health institutions, and especially to patients with ureteral catheters. The treatment of any type of urinary tract infection must include the examination of the effect of antibiotic agents used. The fundamental aims of the treatment of urinary tract infection are: the eradication of causes of infection and concurrent prevention or optimal control of recurrent infection. As long as the patients with urinary tract calculosis are susceptible of permanent infections. It is indispensable to perform sterilization, and thereafter to remove the stone from the urinary tract, because infection of the urinary tract may cause a series of sequelae in the function of the kidney. Frequently the successful urinary sterilization with antibiotic agents cannot be achieved, and consequently, the carrying out of extracorporeal lithotripsy together with administration of antibiotics, is impossible. Good results can be obtained by a combined therapy of antibiotics and extracorporeal lithotripsy in patients with urinary tract calculosis. (ABSTRACT TRUNCATED)     

Two-level optimal output feedback stabilizer design

The paper addresses the design of two-level power system stabilizers using an optimal reduced order model whose state variables are torque angles and speeds. The reduced order model retains their physical meaning and is used to design a two-level linear feedback controller that takes into account the realities and constraints of electrical power systems. The two-level control strategy is used, and a global control signal is generated from the output variables to minimize the effect of interactions. The effectiveness of this controller is evaluated and a multimachine system is given as an example to illustrate the advantages of the proposed method. Responses of the system with a two-level scheme and an optimal reduced order scheme are included for comparative analysis.     

Differential effects of aging on directional and absolute errors in visuospatial memory.

Studied memory for visuospatial arrays in 28 male and 34 female healthy dextral adults (aged 20–90 yrs). 10 abstract figures were presented in each hemispace over a series of learning trials, and then delayed free recall of figure placement was obtained. Figures were misplaced significantly downward and leftward in both hemispaces. Both vertical and horizontal absolute error increased significanty with age, but no age effects on directional errors were observed. The increase in absolute error over age is consistent with decreased anterograde memory and visuospatial skills in the elderly. The directional errors are believed to result from an attentional shift toward proximal peripersonal space, in combination with attentional shifts from differential left vs right cerebral activation. Gender effects were also observed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cure reaction for modified diallylbisphenol A/diaminodiphenylsulfone/bismaleimide

The glass‐transition temperature as a function of curing conversion for a modified diallylbisphenol A/diaminodiphenylsulfone/bismaleimide (BMI) resin was investigated at different temperature regimes and modeled using a modified Di Benedetto equation. Although the relationship between the glass‐transition temperature and conversion of the BMI system conforms to the Di Benedetto equation for α < 0.6 and at lower cure temperatures, at higher cure temperatures the results deviated significantly from the equation; thus, it was an inadequate model for the system. Fourier transform IR analysis showed that the major crosslinking reactions did not occur during cure for the modified BMI at and below 150°C. However, as the cure temperature was increased, the crosslinking reactions responsible for 3‐dimensional network structures became more dominant. At 190°C the C? N? C_stretch vibration of the uncured maleimide ring converted into succinimide rings in the curing process. Simultaneously, a decrease was observed for the absorbance bands of ? C? H_bending (maleimide). The higher cure temperatures induced a significantly faster initial crosslinking rate and also resulted in a shorter period of time after which further crosslinking was retarded, because the increase in the crosslinks also physically slowed further crosslinking activity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 227–235, 2002     

Anabaena sp. strain PCC 7120 responds to nitrogen deprivation with a cascade-like sequence of transcriptional activations

Anabaena sp. strain PCC 7120 adapts to deprivation of fixed nitrogen by undergoing physiological and genetic changes that include formation of N2-fixing heterocysts. Whether or not certain of the genes involved are interdependently expressed has been studied.