Roadmap on thermoelectricity

The increasing energy demand and the ever more pressing need for clean technologies of energy conversion pose one of the most urgent and complicated issues of our age. Thermoelectricity, namely the direct conversion of waste heat into electricity, is a promising technique based on a long-standing physical phenomenon, which still has not fully developed its potential, mainly due to the low efficiency of the process. In order to improve the thermoelectric performance, a huge effort is being made by physicists, materials scientists and engineers, with the primary aims of better understanding the fundamental issues ruling the improvement of the thermoelectric figure of merit, and finally building the most efficient thermoelectric devices. In this Roadmap an overview is given about the most recent experimental and computational results obtained within the Italian research community on the optimization of composition and morphology of some thermoelectric materials, as well as on the design of thermoelectric and hybrid thermoelectric/photovoltaic devices.

Resveratrol-like Compounds as SIRT1 Activators

The sirtuin 1 (SIRT1) activator resveratrol has emerged as a promising candidate for the prevention of vascular oxidative stress, which is a trigger for endothelial dysfunction. However, its clinical use is limited by low oral bioavailability. In this work, we have applied a previously developed computational protocol to identify the most promising derivatives from our in-house chemical library of resveratrol derivatives. The most promising compounds in terms of SIRT1 activation and oral bioavailability, predicted in silico, were evaluated for their ability to activate the isolated SIRT1 enzyme. Then, we assessed the antioxidant effects of the most effective derivative, compound 3d, in human umbilical vein endothelial cells (HUVECs) injured with H₂O₂ 100 µM. The SIRT1 activator 3d significantly preserved cell viability and prevented an intracellular reactive oxygen species increase in HUVECs exposed to the oxidative stimulus. Such effects were partially reduced in the presence of a sirtuin inhibitor, sirtinol, confirming the potential role of sirtuins in the activity of resveratrol and its derivatives. Although 3d appeared less effective than resveratrol in activating the isolated enzyme, the effects exhibited by both compounds in HUVECs were almost superimposable, suggesting a higher ability of 3d to cross cell membranes and activate the intracellular target SIRT1.

Influence of male human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection on the reproductive outcomes in serodiscordant couples: a case-control study

BACKGROUND

Nowadays, serodiscordant couples (SDCs) with human immunodeficiency virus (HIV) or hepatitis C virus (HCV)-infected men have the chance to conceive safely, giving birth with a minimum risk of cross-infection.

OBJECTIVE

To assess the impact of male HIV and HCV infection on the assisted reproductive technologies (ART) outcomes in SDCs, with HIV or HCV seropositive men and negative partners.

MATERIALS AND METHODS

Of 153 couples: 24 in Group 1 (HIV-seropositive men), 60 in Group 2 (HCV-seropositive men) and 69 in Group 3 (controls). Sperm-washing procedure was performed using a three-step system. Fresh ICSI cycles were carried out in HIV SDCs, HCV SDCs and controls. Seminal parameters, fertilization rate (FR), cleavage rate (CR), pregnancy rate per cycle (PR/C), miscarriage rate, implantation rate (IR) and live birth rate were evaluated.

RESULTS

All the seropositive men have undetectable viral loads at the time of insemination, and both partners were free from co-morbid infections. The median number of embryos transferred was 2.0 (IQR 1.0-3.0), with no differences among groups. FR was significantly reduced in HIV and HCV SDCs compared to the controls (66%, 61% and 75%, respectively; p < 0.01). CR was similar between groups (p = 0.3). IR was 12.1%, 11.1% and 14.1%, respectively, in the three groups (p = 0.30). PR/C was 21.7%, 17.6% and 20.2% in HIV, HCV and controls, respectively. Live birth rate per cycle was 17.4%, 15.7% and 15.9%, respectively. There were no significant differences in clinical pregnancies per cycle, as well as miscarriages and live births (p = 0.30; 0.30; 0.60, respectively).

CONCLUSIONS

The sperm-washing technique with ICSI may generate a promising way to improve pregnancy outcomes and to reduce the risk of viral transmission in these couples. In this setting, we can correctly counsel HIV- and HCV-infected men of SDCs with regard to the likelihood of father their own biological child.

Clinical relevance of phenotype/genotype correlations in the diagnosis and therapy of pheochromocytomas/paragangliomas

Pheochromocytomas and paragangliomas are tumors arising from neural crest-derived cells. They can be sympathetic in origin, catecholamine secreting and located in the abdomen or chest, or parasympathetic, generally non-secreting and located in the head and neck region. It is well established that about 35% of them are genetically determined. Germ-line mutations in one of the 10 so far known susceptibility genes is especially suspected when the tumors are diagnosed in young patients, multiple or recurrent or associated with additional lesions typical of syndromic clinical pictures such as von Hippel-Lindau, Multiple Endocrine Neoplasia type 2 or Neurofibromatosis type 1. Tumor genetic profile determines the type and pattern of catecholamine release, the clinical presentation, the risk of malignancy and may influence the choice of the radiotracers used in functional imaging, the type of surgical procedures as well as the type of medical therapy in the treatment of metastatic disease.

Secretion of monovalent ions and water in ferret salivary glands: a micropuncture study

The acinar mechanisms of secretion of the monovalent ions, Na+, K+, Cl-, and HCO3-, and water in the parotid and submandibular glands of the ferret, Mustela putorius furo, were investigated using micropuncture and microanalytical techniques during salivation induced by pilocarpine. The osmolarity and monovalent ionic composition of the primary secretory fluid obtained from the intercalated ducts of these glands were determined.

Transductal fluxes of water and monovalent ions in ferret salivary glands

The net transductal fluxes of water and monovalent ions were measured in the parotid and submandibular salivary glands of the ferret, Mustela putorius furo, during stimulation of secretion with pilocarpine. The duct systems of these glands were found to be impermeable to water using the split-oil droplet method for stationary microperfusion of lobular and main ducts. The net transductal fluxes of Na+, K+, Cl-, and HCO3- were characterized by analysis of ductal fluid samples obtained simultaneously from the intercalated, lobular, and main ducts of these glands.

Handling of calcium by the ferret submandibular gland

The handling of Ca by the submandibular gland of the ferret during stimulation of salivation with pilocarpine was studied using micropuncture and microanalytical, as well as standard, physiological techniques. Concentrations of ionized Ca were measured in the fluid from the intercalated, lobular, and main ducts of the gland. The net transductal fluxes of this divalent ion were calculated.

Transductal fluxes of water and monovalent ions in ferret salivary glands

The net transductal fluxes of water and monovalent ions were measured in the parotid and submandibular salivary glands of the ferret, Mustela putorius furo, during stimulation of secretion with pilocarpine. The duct systems of these glands were found to be impermeable to water using the split-oil droplet method for stationary microperfusion of lobular and main ducts. The net transductal fluxes of Na+, K+, Cl-, and HCO3- were characterized by analysis of ductal fluid samples obtained simultaneously from the intercalated, lobular, and main ducts of these glands.

Excretion of monovalent ions and water in the saliva of the ferret

The excretion of water and the monovalent ions Na+, K+, Cl-, and HCO-3 in the parotid and submandibular saliva of the ferret was studied during pilocarpine-induced salivation. The excretory profiles of these ions were very similar to those of dog, monkey, and man. It was concluded that this docile small carnivore is a useful animal for studies of salivary gland physiology.