Potential Energy Landscape and Long Time Dynamics in a Simple Model Glass

We analyze the properties of a Lennard-Jones system at the level of the potential energy landscape. After an exhaustive investigation of the topological features of the landscape of the systems, obtained studying small size sample, we describe the dynamics of the systems in the multi-dimensional configurational space by a simple model. This consider the configurational space as a connected network of minima where the dynamics proceeds by jumps described by an appropriate master equation. Using this model we are able to reproduce the long time dynamics and the low temperature regime. We investigate both the equilibrium regime and the off-equilibrium one, finding those typical glassy behavior usually observed in the experiments such as: {\it i)} stretched exponential relaxation, {\it ii)} temperature-dependent stretching parameter, {\it iii)} breakdown of the Stokes-Einstein relation, and {\it iv)} appearance of a critical temperature below which one observes deviation from the fluctuation-dissipation relation as consequence of the lack of equilibrium in the system.Comment: 11 pages (Latex), 9 ps figure

Monitoring of pregnancy complicated by maternal-fetal isoimmunization. A comparison between two clinical protocols

AIM: Invasive techniques such as amniocentesis and cordocentesis are used for the diagnosis and treatment of fetus at risk for anemia due to maternal red-cell alloimmunization. The purpose of this study was to determine the value of non invasive measurements of the peak velocity middle cerebral artery in the fetus (PVMCA) for the diagnosis of fetal anemia. METHODS: From 1996 to September 2002, we studied 23 pregnancies with anti D title >1:32. In the 1(st) group of 11 women (from 1996 to 1999) fetal anemia was detected by invasive techniques (amniocentesis and cordocentesis). In the 2(nd) group of 12 women (from 1999 to 2002) fetal anemia was suspected on the basis of PVMCA. When PVMCA was significantly increased, cordocentesis was performed in order to rule out fetal anemia and to provide in utero transfusions. RESULTS: In the 1(st) period we performed 23 invasive techniques (7 amniocentesis and 16 cordocentesis) in 11 women, but we identified fetal anemia only in 4 cases. In the 2(nd) period we performed only 2 cordocentesis in women in which PVMCA was increased; the blood sampling confirmed fetal anemia in both cases. CONCLUSION: PVMCA and fetal hematocrit are highly significantly correlated: high values of PVMCA are associated with fetal anemia. Doppler velocity of PVMCA is related to fetal anemia with positive predictive value 100% and negative predictive value 100%. The middle cerebral artery blood velocity is a non invasive technique for detecting anemia in pregnancies complicated by alloimmunization

Labor course and delivery in epidural analgesia: a case-control study

8nonenoneDECCA L; DALDOSS C; FRATELLI N; A. LOJACONO; SLOMPO M; STEGHER C; VALCAMONICO A; FRUSCA TDecca, L; Daldoss, C; Fratelli, N; Lojacono, Andrea; Slompo, M; Stegher, C; Valcamonico, A; Frusca, Tizian

Labor course and delivery in epidural analgesia: a case-control study

BACKGROUND: We aimed to establish if epidural analgesia is associated with a higher incidence of operative vaginal delivery, longer duration of labor and more frequent use of oxytocin than labor without analgesia. METHODS: We analyzed a cohort of 207 women with no risk factors who delivered with epidural analgesia in the labor unit of Spedali Civili, Brescia, Italy, during 2001. Length of the first and second stage of labor, mode of delivery, neonatal cord blood pH, neonatal Apgar score and neonatal outcomes were evaluated. RESULTS: Epidural analgesia was performed on request in 6%: in this group (group A) there were 141 (68%) nulliparae and 66 (32%) pluriparae; mean ( +/- standard deviation) gestational age at delivery was 39.4 +/- 1.3 weeks (range: 34.1-41.5 weeks). In this group, 184 (89%) had vaginal delivery and 23 (11%) delivered by Cesarean section. Among controls (group B), 368 (89%) had a vaginal delivery and 46 (11%) delivered by Cesarean section; vacuum extraction was used in 18 deliveries (9%) in group A and in 13 deliveries (3%) in group B. The duration of the second stage of spontaneous labor in the nulliparae of group A was significantly longer than in group B. No statistically significant differences were found between mean umbilical artery pH values of groups A and B. CONCLUSION: Our results confirm that epidural analgesia does not affect the rate of Cesarean delivery, while increasing the use of oxytocin augmentation, the duration of the second stage of labor and the rate of instrumental vaginal delivery

A two-by-two factorial trial comparing oral with transdermal estrogen therapy and fenretinide with placebo on breast cancer biomarkers

Purpose: Oral conjugated equine estrogen (CEE) and medroxyprogesterone acetate (MPA) increase breast cancer risk, whereas the effect of transdermal estradiol (E2) and MPA is less known. Fenretinide may decrease second breast malignancies in premenopausal women but not in postmenopausal women, suggesting a hormone-sensitizing effect. We compared the 6 and 12-month changes in insulin-like growth factor-I (IGF-I), IGF-binding protein-3 (IGFBP-3), IGF-I:IGFBP-3 ratio, sex-hormone binding-globulin, and computerized mammographic percent density during oral CEE or transdermal E2 with sequential MPA and fenretinide or placebo. Experimental Design: A total of 226 recent postmenopausal healthy women were randomly assigned in a two-by-two factorial design to either oral CEE 0.625 mg/day (n = 111) or transdermal E2, 50 mug/day (n = 115) and to fenretinide 100 mg/twice a day (n = 112) or placebo (n = 114) for 12 months. Treatment effects were investigated by the Kruskall-Wallis test and analysis of covariance. P values were two-sided. Results: After 12 months, oral CEE decreased IGF-I by 26% [95% confidence interval (CI), 22-30%] and increased sex-hormone binding-globulin by 96% (95% CI, 79-112%) relative to baseline, whereas no change occurred with transdermal E2 (P < 0.001 between groups). Fenretinide decreased IGFBP-3 relative to placebo (P = 0.04). Percentage of breast density showed an absolute increase of 3.5% (95% CI, 2.5-4.6%) during hormone therapy without differences between groups (P = 0.39). Conclusions: Oral CEE has more favorable changes than transdermal E2 on circulating breast cancer risk biomarkers but gives similar effects on mammographic density. Fenretinide exerted little modulation on most biomarkers. The clinical implications of these findings require additional studies