University of Cagliari

About: University of Cagliari is a education organization based out in Cagliari, Italy. It is known for research contribution in the topics: Population & Dopamine. The organization has 11029 authors who have published 29046 publications receiving 771023 citations. The organization is also known as: Università degli Studi di Cagliari & Universita degli Studi di Cagliari.

Second-order sliding-mode control of DC drives

Abstract: One of the most recent topics in variable-structure systems theory is represented by the second-order sliding-mode control (2-SMC) methodology. This approach guarantees the same robustness and dynamic performance of traditional first-order SMC algorithms, and, at the same time, attenuates the chattering phenomenon, which is the main drawback in the actual implementation of this technique. In the present paper, a recently-proposed 2-SMC algorithm is used to synthesize a robust dc-drive control system which does not require current feedback and demands only rough information about the actual motor parameters. Stability and performance are analyzed, and an experimental comparison with a proportional-integral-based control scheme is reported.

The adiponectin gene SNP+276G>T associates with early-onset coronary artery disease and with lower levels of adiponectin in younger coronary artery disease patients (age ≤50 years)

Abstract: Adiponectin, an adipocyte-derived protein, is an essential modulator of insulin sensitivity and several studies suggest an important role of adiponectin in the processes leading to atherosclerosis, thus indicating the adiponectin gene as a potential candidate for coronary artery disease (CAD). In the present study we have studied the association between two single nucleotide polymorphisms (SNPs) (+45T>G and +276 G>T) of the adiponectin gene and CAD, looking also into the possible influence of these SNPs on adiponectin plasma levels. The SNPs were analysed in a first cohort of 595 subjects, 325 with CAD and 270 matched controls. We observed a significant association (p T in the adiponectin gene and CAD. In multivariate analysis, carriers of the +276G>T SNP had an odds ratio (OR) for CAD of 4.99 (p T SNP and age was also present (OR, 1.03; p T SNP was analysed in a second cohort of CAD and controls. The difference between CAD and controls in the +276G>T SNP frequencies showed a similar trend as before, although not significant. The combination of the two cohorts (1,046 subjects: 580 CAD and 466 controls) showed a statistically significant association, particularly in CAD subjects with early-onset of disease. In addition, we confirmed that in younger CAD subjects the SNP was a significant determinant of lower levels of adiponectin. In view of these results, it could be speculated that the adiponectin gene variant, or a mutation in linkage with it, determines lower adiponectin gene expression, causing in turn an increased risk to develop insulin resistance, atherosclerosis and cardiovascular disease. The significant association of the adiponectin gene in subjects with early-onset CAD also suggests that that genetic factors for late-onset diseases may exert a greater influence in younger persons, when other risk factors are not as prevalent as in older age groups.

Morphology and functions of the human seminal vesicle

Abstract: The seminal vesicles originate in embryos of about 58 mm crown-rump-length from the Wolffian duct under the influence of testosterone. Along with the ampulla of the vas deferens and the ejaculatory duct, they form a functional unit that develops slowly until the onset of puberty. Developmental malformations occur as uni- or bilateral agenesis, aplasia, cysts, or ureterovesicular fistules. After puberty, the glands form sac-like structures which have a capacity of about 3.4-4.5 ccm and contribute about 70% of the seminal fluid. In addition to secretion, they are capable of reabsorption of fluids or dissolved substances, and of spermatophagy (ingestion and degradation of damaged spermatozoa by epithelial cells). Secretory activity of the glands is a measure of testosterone supplementation to the epithelium. Nervous regulation of secretion is realized by cholinergic post-ganglionic, sympathetic (and perhaps parasympathetic) fibres, derived from pelvic plexus. Contraction of the muscular wall occurs under the influence of excitatory adrenergic and modulatory NPY-encephalin-peptidergic nerve fibres. The secretory products of the seminal vesicles encompass (1) ions (K+: 1.1 mM ml-1) (2) low molecular weight substances (fructose: above 1.2 mg ml-1; prostaglandins above 250 microliters ml-1, (3) peptides (endorphin: 330 pg ml-1), and (4) proteins. In addition to plasma protein related forms such as transferrin, lactoferrin, and fibronectin, specific proteins such as semenogelin (52 kDa) are synthesized, the scaffold protein of semen coagulate forming the substrate for PSA (prostate specific antigen), sperm motility inhibitor (ca. 18 kDa), and others (placental protein 5, protein kinase inhibitor, carboanhydrase, 5'-nucleotidase), some of which are immunosuppressive. Therefore, functions of the seminal vesicles concern (a) formation of seminal coagulum, (b) modification of sperm functions (motility, capacitation), and (c) immunosuppression. Additional functions within the female genital system, perhaps during pre-implantation period, are likely, but remain to be proven experimentally.

Hypocalcemia following thyroid surgery: incidence and risk factors. A longitudinal multicenter study comprising 2,631 patients

Abstract: Postoperative hypocalcemia is the most frequent complication of total thyroidectomy. It may have a delayed onset, and therefore delays the discharge from the hospital, requiring calcium replacement therapy to alleviate clinical symptoms. During a 7-month period, 2,631 consecutive patients undergoing primary or completion thyroidectomy were prospectively followed up and underwent analysis regarding postoperative hypoparathyroidism. Data were prospectively collected by questionnaires from 39 Italian endocrine surgery units affiliated to the Italian Endocrine Surgery Units Association (Club delle Unita di EndocrinoChirurgia-UEC), where thyroid surgery is routinely performed. The incidence of hypoparathyroidism was 28.8 % (757 patients), including transient hypocalcemia (27.9 %-734 patients) and permanent hypocalcemia (0.9 %-23 patients). The rate of asymptomatic hypocalcemia was 70.80 %. The incidence of permanent hypocalcemia was higher in the symptomatic hypocalcemia group (7.5 %) than in asymptomatic one (1.5 %). Female patients experienced a transient postoperative hypocalcemia more frequently than male patients (29.7 and 21.2 %, respectively; p < 0.0001). The percentage developing hypocalcemia in patients in which parathyroid glands were intraoperatively identified and preserved was higher than in the patients in which the identification of parathyroid glands was not achieved (29.2 vs. 18.7 %, p < 0.01). This prospective study confirmed the main risk factors for postoperative hypocalcemia: thyroid cancer, nodal dissection, and female gender. It farther showed that identifying parathyroids has an important role to prevent permanent hypocalcemia though with a higher risk of transient hypocalcemia. A suitable informed consent should especially emphasize the importance of some primary factors in increasing the risk of hypocalcemia after thyroid surgery.

ESBRA-Nordmann 1996 Award Lecture: ethanol drinking behaviour in Sardinian alcohol-preferring rats.

Abstract: Sardinian alcohol-preferring (sP) rats have been selectively bred for high ethanol preference and consumption over 16 years and 39 generations. The present paper briefly reviews some recent studies from this laboratory characterizing ethanol drinking behaviour in this rat line. Under the two-bottle regimen of free choice between 10% (v/v) ethanol and water, sP rats consume daily >4 g of ethanol/kg and avoid water almost completely. Relevant features of ethanol drinking behaviour in sP rats are: (a) attainment of high ethanol intake from the first day of exposure to ethanol, suggestive of an immediate disclosure and acquisition of ethanol reinforcement; (b) titration of daily ethanol intake in distinct binges during the nocturnal phase of the light/dark cycle, indicative of their ability to regularize both ethanol dose and administration time; (c) achievement of pharmacologically relevant blood ethanol levels at each drinking episode; (d) substitution of the calories provided by ethanol for a part of those taken from food; (e) maintenance of constant ethanol intake (in g/kg/day) in the presence of ethanol concentrations varying from 7 to 30% (v/v). These results suggest that voluntary ethanol intake in sP rats is sustained by the search for specific pharmacological effects of ethanol. Anxiolysis is likely to be one of these effects; indeed, voluntarily consumed ethanol reversed the innate, high levels of anxiety in sP rats. These results portray sP rats as a valid model for investigating the association between ethanol drinking and anxiety. Finally, the breeding programme as well as results of neurochemical studies are also described.