Search

Trabajo presentado al: 69th Wildlife Disease Association and 14th European Wildlife Disease Association Conference. Cuenca, Spain. p. 135. 31 agosto-2 septiembre.

The interior of living cells is a dense and polydisperse suspension of macromolecules. Such a complex system challenges an understanding in terms of colloidal suspensions. As a fundamental test we employ neutron spectroscopy to measure the diffusion of tracer proteins (immunoglobulins) in a cell-like environment (cell lysate) with explicit control over crowding conditions. In combination with Stokesian dynamics simulation, we address protein diffusion on nanosecond time scales where hydrodynamic interactions dominate over negligible protein collisions. We successfully link the experimental results on these complex, flexible molecules with coarse-grained simulations providing a consistent understanding by colloid theories. Both experiments and simulations show that tracers in polydisperse solutions close to the effective particle radius Reff = ⟨ Ri3⟩1/3 diffuse approximately as if the suspension was monodisperse. The simulations further show that macromolecules of sizes R > Reff ( R < Reff) are slowed more (less) effectively even at nanosecond time scales, which is highly relevant for a quantitative understanding of cellular processes.

Nucleation is an out-of-equilibrium process that can be strongly affected by the presence of external fields. In this paper, we report a simple extension of classical nucleation theory to systems submitted to an homogeneous shear flow. The theory involves accounting for the anisotropy of the critical nucleus formation and introduces a shear-rate-dependent effective temperature. This extended theory is used to analyze the results of extensive molecular dynamics simulations that explore a broad range of shear rates and undercoolings. At fixed temperature, a maximum in the nucleation rate is observed, when the relaxation time of the system is comparable to the inverse shear rate. In contrast to previous studies, our approach does not require a modification of the thermodynamic description, as the effect of shear is mainly embodied into a modification of the kinetic prefactor and of the temperature. © 2013 American Physical Society.

In a series of 818 patients treated with indomethacin during pregnancy, the rate of perinatal complications was 1.8%. The risk was increased to 13% if indomethacin was being taken at the time of delivery, and when treatment was prolonged. The serious nature of certain complications (persistence of fetal circulation and oligo/anuria) means that indomethacin should only be used in cases in which betamimetic drugs are formally contraindicated or if there is a risk of unacceptable prematurity. Even in such cases, indomethacin should only be given for short period (1 week).

Nonequilibrium atomic dynamics is simulated in single-component metallic glass under the influence of shear strains with different shear rates and temperatures. Based on the simulation data and cluster analysis, such parameters of nucleation processes as the nucleation rate, the size of a critical cluster, and the Zeldovich factor are found. The dependence of these quantities on the shear rate is discussed. © 2011 Allerton Press, Inc.

Objective : The purpose of the study is to assess the efficacy of and adverse events linked to the use of intravenous sulprostone during the 2nd or 3rd trimesters of pregnancy for therapeutic abortion. Study design : One hundred eighty-two patients (70 nulliparous, 112 multiparous) were hospitalized for therapeutic abortion. The route of administration was invariably intravenous and one single dose of sulprostone was used: 1000 μg of sulprostone diluted in 11 of isotonic saline solution given as a 10-h infusion. Result : Expulsion within the first 24 h was obtained in 70% of cases with a mean induction-expulsion interval of 14 h. In three cases, laparotomy was required for hemorrhagic syndromes. Conclusion : Intravenous sulprostone enable evacuation of uterine contents with minimal adverse reaction. Attention should nevertheless be drawn to the existence of hemorrhagic syndromes.

A preliminary study in 22 patients with uterine scarring was undertaken using sulprostone by intravenous infusion when therapeutic abortion was deemed necessary during the 2nd and 3rd trimesters of pregnancy. The dosage used was 500 μg by slow infusion lasting 10 h. There were no cases of ruptured uterus. Adverse reactions were absent. Results were satisfactory. Mean induction-expulsion duration: 11 h. Expulsion rate in 24 h: 63%. With strict monitoring and in a specialized center, this technique may be suggested when a late therapeutic abortion with a scarred uterus is indicated.

Crystal nucleation and growth processes induced by an externally applied shear strain in a model metallic glass are studied by means of nonequilibrium molecular dynamics simulations, in a range of temperatures. We observe that the nucleation-growth process takes place after a transient, induction regime. The critical cluster size and the lag-time associated with this induction period are determined from a mean first-passage time analysis. The laws that describe the cluster-growth process are studied as a function of temperature and strain rate. A theoretical model for crystallization kinetics that includes the time dependence for nucleation and cluster growth is developed within the framework of the Kolmogorov-Johnson-Mehl-Avrami scenario and is compared with the molecular dynamics data. Scalings for the cluster-growth laws and for the crystallization kinetics are also proposed and tested. The observed nucleation rates are found to display a nonmonotonic strain rate dependency. © 2010 The American Physical Society.

Nonequilibrium molecular dynamics simulations of a model amorphous system are performed with the aim of studying the structural transformations induced by external shear influence. We reveal that the shear drive has both positive and negative effects on the structural ordering processes. The dependence of the phase transition rate versus the strain rate at three different temperatures is found. © 2010 Allerton Press, Inc.

Although vaginal ultrasonography combined with plasma beta-hCG determination can provide a reliable diagnosis and location of ectopic pregnancy, the results can be difficult to interpret in the early stages when hCG levels are low. Hysteroscopy can be used in such cases to differentiate between ectopic pregnancy and non-viable uterine pregnancy when viable uterine pregnancy has been ruled out. General anaesthesia and laparoscopy are avoided. We performed 60 hysteroscopic procedures between January 1989 and December 1990 in patients with suspected ectopic pregnancies. The pregnancy had been located by means of vaginal ultrasonography in every case in which the hCG was above 1500 IU/ml and in 36% of cases in which the beta-hCG was below this level. Hysteroscopy was hindered by metrorrhagia in three cases and was inconclusive in one, necessitating laparoscopy. Diagnosis was possible in all the remaining cases, as follows: ectopic pregnancy in 41 cases, with an empty uterus and occasional bleeding from an ostium; non-viable uterine pregnancy in 18 cases, with the presence of material within the cavity. Hysteroscopy therefore confirmed the diagnosis in 55% of the cases and was itself diagnostic in a further 43% of cases. Its sensitivity for the diagnosis of ectopic pregnancy was 100% and its specificity 95%. We propose a diagnostic decision tree.

We report the case of a dichorionic and diamniotic pregnancy with the unique feature of an early ultrasound diagnosis of a 4-week size difference, which persisted throughout pregnancy. At birth, the twins had a 1-month difference in physical and neurological maturity. We believe that only the phenomenon of a superfetation can explain this difference. We report the cases found in the literature. Copyright © 1992 International Society of Ultrasound in Obstetrics and Gynecology

40 patients with advanced ovarian cancer were treated with immediate debulking followed by sequential cisplatin and doxorubicin every 4 weeks, followed by second-look laparotomy (SLL). Six courses were given when residual disease (RD) was under 2 cm. When RD was over 2 cm, three courses were followed by early debulking and six more courses before SLL. Immediate debulking was optimal in 15 patients (38%) and early debulking in an additional 15 (38%). Pathological complete responses (34 evaluable cases) were observed in 14 cases (41%), partial response in 13 (38%), stable disease in 3 (9%) and progression in 5 (15%). Toxicity was mainly haematological. 11 patients with negative SLL and 15 with RD under 2 cm received intraperitoneal cisplatin 200 mg/m2 alone or with cytarabine. Median survival was 45 months: 58 months for RD under 2 cm at initial laparotomy and 31 months for RD over 2 cm. Median survival was 46 months when early debulking was successful. 5 year disease-free survival was only 16%. However, this multimodal treatment offers prolonged survival, especially in patients optimally debulked either at initial laparotomy or at early debulking surgery.

We report results of nonequilibrium molecular dynamics simulations of a one-component glassy system under the influence of a shear flow, with the aim of investigating shear-induced ordering of this system. In spite of the very low temperature, the system transforms into a strained crystalline state through well defined nucleation events. Various characteristics of the observed ordering at different strain rates and temperatures are discussed. We also define and discuss the transition rates. © 2009 American Institute of Physics.

By modification of the circulating pool of biliary acids, the administration of ursodesoxycholic acid has permitted the restoration of normal maternal hepatic function during a triple pregnancy complicated by the precocious onset of an intrahepatic cholestasis. The marked regression in clinical and biological markers of the disease confirms the role of biliary acids in the aggravation of hepatic abnormalities.

Early secondary cytoreductive surgery was performed in 36 cases of advanced ovarian carcinoma. Optimally debulking was feasible in 76 %. Median survival time was 45 months, similar to that of optimally debulked patients at first laparotomy.

Second-look laparotomy (SLL) was performed after chemotherapy in 86 patients with advanced epithelial ovarian cancer. Seventy-one patients received cisplatin-based regimens. Median follow-up was 66 months. Negative SLL was found in 32 patients who had a 5-year survival rate of 48.3% after SLO. Microscopic residual disease was present in seven patients whose 5-year survival rate was 35.7%. Maximum residual tumor of 2 cm or less was found in 13 patients with a 5-year survival rate of 30%. Residual tumor larger than 2 cm after secondary cytoreduction was present in 20 patients; their 3-year survival rate was 19.7%. Fourteen patients with bulky residual disease who did not have cytoreduction were all dead within 17 months. Patients with initial residual tumor at first laparotomy less than 2 cm had a nearly significant advantage in survival rate over patients with residual disease greater than 2 cm and stage IV (P = 0.07). Non-responders to initial chemotherapy had a survival rate similar to that of partial responders. These findings justify discontinuation of conventional systemic chemotherapy for patients showing residual disease after SLL and secondary tumor removal in case of residual tumor at SLL. Therapeutic trials are needed in advanced ovarian cancer testing initial aggressive surgery or early debulking to avoid bulky residual disease, and consolidation therapy in patients who achieved complete pathological response or minimal residual disease.

NWA 5790 is a recently discovered nakhlite. Its mineralogy, petrology and geochemistry suggest that it is the topmost sequence of the nakhlite lava pile.

The Diderot meteorite is a dunite discovered in Sahara. The martian origin is unambiguous and Diderot shares strong petrographical similarities with Chassigny.

The safety of the SAG2 rabies virus, a highly attenuated mutant of the SAD strain intended to vaccinate dogs by the oral route, was evaluated in local Tunisian dogs and in five other local species likely to consume vaccine baits. These species were the domestic cat (Felis catus), the jackal (Canis aureus), the jerboa (Jaculus orientalis), the merion (Meriones sp.) and the gerbil (Gerbillus campestris). The vaccine was administered orally to 21 dogs, 11 cats and eight jackals and orally or intramuscularly to 62 wild rodents of the above-mentioned species. Seven dogs, one cat, five jackals all juvenile and with poor health status) and two rodents died for intercurrent causes. The others were observed for 60-180 days. No animal showed any rabies symptom. Seroneutralizing antibodies were observed in all experimental groups, only after vaccination, with the highest rate being observed in jackals and rodents. The rabies virus was detected in the oral cavity of three cats 6 h after oral instillation, but was not isolated later either in saliva or in salivary glands. Tissue samples (brain and salivary glands) from dead or euthanized animals were examined for the rabies virus antigen by a fluorescent antibody test. No rabies antigen was detected. These trials confirm the safety of the SAG2 strain on the Tunisian species already demonstrated by other authors on many other target and non target species.

The behavior of alpha-quartz under hydrostatic and nonhydrostatic high-pressure conditions has been investigated in molecular dynamics simulations of silica in order to clarify the role of nonhydrostatic stresses in the amorphization process. It is shown that the amorphization threshold is not modified if the stress along the c direction is lowered, so that the mean amorphization pressure can effectively be lowered under nonhydrostatic conditions. On the other hand, the application of a positive uniaxial stress along the c axis results in the appearance of a new crystalline phase, where all silicon atoms are in fivefold coordination.

Our data show that HED meteorites have a homogeneous oxygen isotopic composition consistent with a magma ocean on Vesta. Ibitira, Asuka 881394, Pasamonte, and NWA 1240 probably come from separate parent asteroids.

An election is a process through which citizens in liberal democracies select their governing bodies, usually through voting. For elections to be truly honest, people must be able to vote freely without being subject to coercion; that is why voting is usually done in a private manner. In this paper we analyze the security offered by a paper-ballot voting system that is used in Israel, as well as in several other countries around the world. we provide an algorithm which, based on publicly available information, breaks the privacy of the voters participating in such elections. Simulations based on real data collected in Israel show that our algorithm performs well, and can correctly recover the vote of up to 96% of the voters., 17 pages