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By making use of a recently proposed framework for the inference of thermodynamic irreversibility in bosonic quantum systems, we experimentally measure and characterize the entropy production rates in the nonequilibrium steady state of two different physical systems-a micromechanical resonator and a Bose-Einstein condensate-each coupled to a high finesse cavity and hence also subject to optical loss. Key features of our setups, such as the cooling of the mechanical resonator and signatures of a structural quantum phase transition in the condensate, are reflected in the entropy production rates. Our work demonstrates the possibility to explore irreversibility in driven mesoscopic quantum systems and paves the way to a systematic experimental assessment of entropy production beyond the microscopic limit.
RESUMEN
Intrauterine insemination (IUI) has latterly become less important in reproductive medicine. The aim of this retrospective analysis was to identify and evaluate the success rates of repeated insemination cycles in women of different ages. All women who underwent intrauterine insemination in the Wiesbaden Fertility Clinic between 1998 and 2010 were included in the analysis. Additional inclusion criteria were: not more than 45 years old, previous FSH stimulation and slight to moderate subfertility of the male partner. A total of 4246 insemination cycles in 1612 patients were included in the analysis. The average number of IUI cycles per patient was 2.24 (1-14). Patient age ranged from 19 to 45 years (mean: 33.9 years). Logistic regression analysis showed a drop in pregnancy rates with increasing age (p = 0.000). However, for the first three cycles the pregnancy rates for women aged 40 and 41 did not differ from those of women aged between 35 and 39 years. Overall pregnancy rates were stable in women up to the age of 40, even after several insemination cycles (7.5 and 10â%). Insemination is therefore still an effective procedure in selected patients. Stable pregnancy rates were recorded even after more than 3 cycles. After 3 cycles, the success rates for women aged 40 and 41 did not differ from those of women below the age of 40.
RESUMEN
OBJECTIVES: To study the prevalence and possible mechanisms of hypocalcaemia in HIV infection and AIDS. SUBJECTS: 828 patients with HIV infection or AIDS and 549 controls. INTERVENTIONS: Measurements of total serum calcium and albumin levels. Parameters of calcium homeostatis were determined in a subgroup of 21 hypocalcaemic AIDS patients. RESULTS: Mean serum calcium was 2.34 +/- 0.13 mmol L-1 in the HIV group vs. 2.46 +/- 0.10 mmol L-1 in controls (P < 0.0001). After adjusting for serum albumin, hypocalcaemia was present in 6.5% of the HIV group vs. 1.1% of controls. Mean serum calcium was declining according to CDC groups, and differed significantly from controls in each group. Regression coefficients of cacium vs. albumin were 0.147 amongst HIV-infected patients and 0.106 for controls. In the subgroup of hypocalcaemic patients with AIDS, 10/21 had vitamin D deficiency, six of these with low ionized calcium levels. Low serum PTH was found in 2/21 patients. Magnesium deficiency in 1/21. Of the remaining eight patients, only one had secondary hyperparathyroidism, while the other seven lacked an adequate PTH response, despite low ionized calcium levels in four subjects. CONCLUSIONS: Mean serum calcium concentrations were lower through all CDC stages, irrespective of albumin, resulting in a higher prevalence of hypocalcaemia in HIV-positive patients compared with controls. In a considerable number, this seems to be caused by vitamin D deficiency and potentially a lack of adequate PTH secretion, but further studies are needed to confirm this.
Asunto(s)
Calcio/sangre , Infecciones por VIH/complicaciones , Hipocalcemia/virología , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Adulto , Estudios de Casos y Controles , Femenino , Infecciones por VIH/sangre , Humanos , Hipocalcemia/sangre , Hipoparatiroidismo/virología , Masculino , Persona de Mediana Edad , Análisis de Regresión , Albúmina Sérica/metabolismoRESUMEN
Biotin labeling of red cells was tested in dogs as a preclinical study for cell survival. Red cells were labeled with either spacered Biotin-X-NHS (BxNHS) or water-soluble biotin compounds. After reinfusion, biotinylated red cells were detected in small blood samples (5 microliters) with flow cytometry. Improved BxNHS labeling allows an easy detection of positive red cells for almost 100 days, whereas labeling with watersoluble compounds-despite strong labeling during the first days-results in a decrease of label, which prevented a discrimation between labeled and negative cells after about 4 weeks. When biotin labeling of red cells was compared with 51Cr labeling, slopes of red cell survival were quite similar after the latter were corrected for elution. Survival slopes were linear, and the mean survival time was t = 93 d. In two blood-donor dogs the slopes of red cell survival where log linear and the mean survival time was t = 45 d. In conclusion, BxNHS, but not the water-soluble biotin compounds, is a good nonradioactive, nontoxic alternative for red cell survival studies. No health hazards are to be expected from the very low dose of Dimethylformamide, which is used as a solvent for biotin-x-NHS.
Asunto(s)
Biotina , Envejecimiento Eritrocítico/fisiología , Animales , Donantes de Sangre , Separación Celular , Radioisótopos de Cromo , Dimetilformamida/toxicidad , Perros , Eritrocitos , Femenino , Citometría de FlujoRESUMEN
The properties of tazasubrate (2-phenyl-2-[(6-ethoxy-2-benzothiazolyl)thio]propionic acid), a potent hypocholesterolemic agent, were studied in rats. Tazasubrate was found to be a reliable and highly effective hypocholesterolemic agent. There was a marked and reproducible reduction of serum cholesterol in various rat models differing in age, sex and diet, an improvement of the pathological lipoprotein pattern, slight but variable effects on serum triglycerides and phospholipids, no accumulation of intermediates of cholesterol biosynthesis, no inhibition of phospholipid metabolism (i.e. no induction of phospholipidosis), no interaction with the thyroid gland, and in contrast to fibrates, only minimal induction of peroxisomes in hepatocytes.