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Newly developed hybrid materials made of magnesium hydroxide and carbon nanotubes were proposed as heat storage medium for MgO/H 2 O/Mg(OH) 2 chemical heat pumps. Samples were synthesized by deposition-precipitation method varying the Mg(OH) 2 load (32–52 wt.%) and the type of carbon nanotubes, pristine or functionalized. The performances of the synthesized materials were evaluated by thermogravimetric analysis, which simulates the chemical heat pump cycle. The presence of the carbonaceous material positively affected the reaction performances, so that the hybrid materials showed improved heat storage/output capacity and faster heat output rate compared to pure Mg(OH) 2 . The functionalization treatment and a proper Mg(OH) 2 load were fundamental to better the dispersibility of Mg(OH) 2 into the carbon nanotubes bundles which in turn enhanced the thermochemical performance of the active material, fully exploiting for the first time its maximum potential heat storage capacity, that is ∼1300 kJ/kg Mg(OH)2 , thus bringing the development of this technology to a level closer to its industrial application. [ABSTRACT FROM AUTHOR]

We have recently reported, in a small cohort of subjects, that acrosome reaction (AR) and intracellular free calcium ([Ca2+]i) increase in response to progesterone were significantly correlated with in-vitro fertilization (IVF) rate. In the present study we extended these results to 90 subjects undergoing IVF. We confirm that both parameters were highly significantly correlated with the fertilization rate (P < 0.001). In particular, significantly lower responses to progesterone were detected in subjects with a fertilization rate < 50%, further enlightening the functional significance of sperm responsiveness to progesterone with respect to the process of fertilization. Moreover, we report here that both tests are highly discriminant of fertilization success, with positive predictive values > 90% for [Ca2+]i values which increase by > 1.2-fold and AR inducibility > 7% (cut-off values). Conversely, AR following challenge with the calcium ionophore A23187 was less significantly correlated with the percentage fertilization rate (P < 0.05), and showed lower predictive values than response to progesterone. All these tests ([Ca2+]i increase in response to progesterone, AR in response to progesterone and to A23187) appear highly sensitive and moderately specific. The positive predictive value may rise to > 95% when the combination of two tests ([Ca2+]i and inducibility of AR in response to progesterone) is considered. No correlation with fertilization rate has been found for spontaneous AR or basal [Ca2+]i. In conclusion, we propose that assessment of human sperm responsiveness to progesterone may be clinically useful in predicting fertilizing ability in vitro. [ABSTRACT FROM AUTHOR]

In this work, novel composite silicone-SAPO-34 foams have been prepared and experimentally characterized for application in desiccant open cycles. Water adsorption isotherms of several samples have been measured by a gravimetric dynamic vapour sorption analyser at 30°C and 70°C up to the relative humidity RH= 75%, representing typical process and regeneration air conditions in desiccant evaporative cooling cycles. Adsorbent foams manufactured with 20%, 40% and 60% weight fraction of SAPO-34 have been compared with the pure SAPO-34 powder. Results highlighted that the prepared foams adsorb a significant amount of water, according to the initial mass fraction of zeolite used in the compound. Moreover, the tested foams exhibited sufficiently fast water sorption rate for practical application in a desiccant open cycle system.

Membrane technologies and materials development appear crucial for the hydrogen/natural gas separation in the impending transition to the hydrogen economy. Transporting hydrogen through the existing natural gas network could result less expensive than a brand-new pipe system. Currently, many studies are focused on the development of novel structured materials for gas separation applications, including the combination of various kind of additives in polymeric matrix. Numerous gas pairs have been investigated and the gas transport mechanism in those membranes has been elucidated. However, the selective separation of high purity hydrogen from hydrogen/methane mixtures is still a big challenge and nowadays needs a great improvement to promote the transition towards more sustainable energy source. In this context, because of their remarkable properties, fluoro-based polymers, such as PVDF-HFP and Nafion TM , are among the most popular membrane materials, even if a further optimization is needed. In this study, hybrid polymer-based membranes were deposited as thin films on large graphite surfaces. Different weight ratios of PVDF-HFP and Nafion TM polymers supported over 200 μm thick graphite foils were tested toward hydrogen/methane gas mixture separation. Small punch tests were carried out to study the membrane mechanical behaviour, reproducing the testing conditions. Finally, the permeability and the gas separation activity of hydrogen/methane over membranes were investigated at room temperature (25 °C) and near atmospheric pressure (using a pressure difference of 1.5 bar). The best performance of the developed membranes was registered when the 4:1 polymer PVDF-HFP/Nafion TM weight ratio was used. In particular, starting from the 1:1 hydrogen/methane gas mixture, a 32.6% (v%) H 2 enrichment was measured. Furthermore, there was a good agreement between the experimental and theoretical selectivity values.

Conducting nanofibers of polyaniline (PANI) doped with camphor-10-sulfonic acid (HCSA) and blended with different polymers, such as polymethyl methacrylate (PMMA) and polyvinyl acetate (PVAc), have been fabricated using the electrospinning technique. Scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA) were utilized to characterize the morphology and the thermal stability of PANI-blended fibers. An extensive study was performed to understand the copolymer influence on both the structural and surface properties of the realized conductive thin films. Samples main electrical characteristics, as conductivity, specific capacitance and electrochemical performances were tested. The better mats were obtained with the use of PVAc copolymer, which showed a conductivity value two orders of magnitude higher than the PMMA system. Aiming at further improving the electrochemical features of these blended mats, hybrid fibers based on PANI/PVAc/graphene oxide and PANI/PVAc/iron oxide were also produced and characterized. The obtained mats were potentially addressed to numerous practical fields, including sensors, health applications, smart devices and multifunctional textile materials.

In this study, UV irradiation was used to improve the response of indium oxide (In 2 O 3 ) used as a CO sensing material for a resistive sensor operating in a low temperature range, from 25 °C to 150 °C. Different experimental conditions have been compared, varying UV irradiation mode and sensor operating temperature. Results demonstrated that operating the sensor under continuous UV radiation did not improve the response to target gas. The most advantageous condition was obtained when the UV LED irradiated the sensor in regeneration and was turned off during CO detection. In this operating mode, the semiconductor layer showed an apparent "p-type" behavior due to the UV irradiation. Overall, the effect was an improvement of the indium oxide response at 100 °C toward low CO concentrations (from 1 to 10 ppm) that showed higher results than in the dark, which is promising to extend the detection of CO with an In 2 O 3 -based sensor in the sub-ppm range.

A new generation of compressor-free heat pumps based on adsorption technology and driven by solar energy is available. Performance and costs are, however, the main obstacles to their commercial diffusion, and more material and system developments are required. In this work, a new coating made of microfibres produced by the electrospinning of polymer/zeolite mixtures is presented. Three different polymer carriers, polyvinyl acetate, polyethylene oxide and polystyrene, have been used together with zeolite SAPO-34 as an adsorbing material. Electrospun microfibres showed a mean diameter ranging from 0.75 μm to 2.16 μm depending on the polymer carrier, with a zeolite content from 60 wt.% to 87 wt.%. Thermal analysis (TGA-DSC) results showed that water desorption from microfibres at T = 150 °C was close to 17 wt.%, a value in agreement with the adsorption capacity of pure SAPO-34. The morphology characterization of coatings demonstrated that the microfibre layers are highly porous and have an elevated surface area.

Prostate cancer (CaP) represents a major leading cause of morbidity and mortality in the Western world. Elevated cholesterol levels, resulting from altered cholesterol metabolism, have been found in CaP cells. Seladin-1 (SELective Alzheimer Disease INdicator-1)/DHCR24 is a recently described gene involved in cholesterol biosynthesis. Here, we demonstrated the androgen regulation of seladin-1/DHCR24 expression, due to the presence of androgen responsive element sequences in its promoter region. In metastatic androgen receptor-negative CaP cells seladin-1/DHCR24 expression and cholesterol amount were reduced compared to androgen receptor-positive cells. In tumor samples from 61 patients who underwent radical prostatectomy the expression of seladin-1/DHCR24 was significantly higher with respect to normal tissues. In addition, in cancer tissues mRNA levels were positively related to T stage. In tumor specimens from 23 patients who received androgen ablation treatment for 3 months before surgery seladin-1/DHCR24 expression was significantly lower with respect to patients treated by surgery only. In conclusion, our study demonstrated for the first time the androgen regulation of the seladin-1/DHCR24 gene and the presence of a higher level of expression in CaP tissues, compared to the normal prostate. These findings, together with the results previously obtained in metastatic disease, suggest an involvement of this gene in CaP.

Although androgens and the androgen receptor (AR) are involved in tumorigenesis of prostate cancer (PC) in initial phases, less clear is the role played in advanced androgen-independent (AI) stages of the disease. Several recent reports indicated that re-expression of AR in PC-derived cell lines determines a less aggressive phenotype of the cells. We have previously demonstrated that re-expression of AR decreases the invasion ability of PC3 cells in vitro by affecting signalling and internalization processes of epidermal growth factor receptor (EGFR). Here, we show that reduced EGFR internalization is also a characteristic of AR positive PC cell lines LNCaP and 22Rv1. Reduced internalization in PC3-AR cells is associated to a defective interaction between the EGFR and two adaptor proteins which mediate the endocytotic process, Grb2 and c-Cbl. As a consequence of such reduced interaction, ubiquitination of the receptor, which is mainly mediated by c-Cbl, is also altered. In addition, we show that internalized EGFR co-localizes with early endosome antigen-1, a marker of clathrin-mediated endocytosis, in PC3-Neo cells but not in AR positive cell lines. Conversely, EGFR maintains co-localization with caveolin-1 after EGF stimulation in PC3-AR cells. These data suggest that expression of AR affects clathrin-mediated endocytosis pathway of EGFR, which, according to recent findings, plays an essential role in the completeness of signalling of the receptor. Taken together, these data emphasize the role of AR in the regulation of EGFR endocytotic trafficking and active signalling in PC cells. In view of the role of EGFR signalling in invasion of carcinoma cells, our data may explain the lower invasive phenotype observed in AR-positive cell lines.

Prostate cancer cells may lose androgen-sensitivity after androgen ablation therapy, becoming highly invasive and metastatic. The biological mechanisms responsible for higher tumurogenicity of androgen-independent prostate carcinomas are not entirely known. We demonstrate that androgen receptor regulation of adhesion and invasion of prostate cancer cells through modulation of alpha6beta4 integrin expression may be one of the molecular mechanisms responsible of this phenomenon. We found that protein and gene expressions of alpha6 and beta4 subunits were strongly reduced in the androgen-sensitive cell line LNCaP respect to the androgen-independent PC3 and that transfection of PC3 cells with a full-length androgen receptor expression vector resulted in a decreased expression of alpha6beta4 integrin, reduced adhesion on laminin, and suppressed Matrigel invasion. Growth in soft agar was also suppressed in androgen receptor-positive PC3 clones. Treatment of androgen receptor positive clones with the synthetic androgen R1881 further reduced alpha6 and beta4 messenger RNA expression as well as adhesion on laminin and Matrigel invasion. Our results indicate that androgens regulate cell-extracellular matrix adhesion and invasion by modulation of integrin expression and function, thus keeping a low invasive phenotype of prostate cancer cells.

The presence of functional nongenomic progesterone (P) receptors in human spermatozoa has been investigated by equilibrium binding studies in intact spermatozoa, ligand blot and Western blot analysis of sperm lysates, as well as determination of the effects of the steroid on sperm intracellular Ca2+ concentrations. Binding experiments were performed using progesterone-11alpha-glucuronide-[125I]iodotyramine as tracer. Computer analysis of competition curves using different steroids as competitors indicated the presence of two distinct binding sites for P. The high affinity site (Kd in the nanomolar range) appears to be specific for P, whereas the low affinity one (Kd in the micromolar range) binds with equal affinity 11beta-hydroxyprogesterone (11betaOHP) and 17alpha-hydroxyprogesterone (17alphaOHP). A significant correlation exists among affinity constants (as determined by binding studies) and EC50 values for the effects of P, 11betaOHP, and 17alphaOHP on intracellular Ca2+ in fura-2-loaded spermatozoa, strongly indicating the involvement of P-binding sites in the biological effect of the steroid. In particular, dose-response curves for P were biphasic, with an EC50 in the nanomolar range and another in the micromolar range. Conversely, curves for 11betaOHP and 17alphaOHP were monophasic, with an EC50 just in the micromolar range. Ligand blot analysis of sperm total lysates performed with peroxidase-conjugated P revealed the presence of two binding proteins of 54 and 57 kDa that were specific for P. Indeed, peroxidase-conjugated P binding was blocked by the simultaneous presence of the unconjugated steroid. Using alpha c262 antibody, which is directed against the P-binding domain of genomic receptor, we detected two proteins of similar molecular mass (54 and 57 kDa), whereas using antibodies directed against the DNA-binding and N-terminal domains of the genomic P receptors, the two proteins were not detected. In addition, p54 and p57 appear to be mostly localized in sperm membranes and virtually absent in the cytoplasm. The involvement of these proteins in the biological effects of P is indicated by the strong inhibitory effect of alpha c262 on P-induced acrosome reaction of capacitated human spermatozoa.

We have previously found the presence of endothelin (ET) receptor and ET-like immunoreactivity in rat testis. We now extend our studies from rat to human testis. We found expression of a specific transcript for ET-1 and ET-1-like immunoreactivity in human testis. Positive staining was confined to the Sertoli cells of the tubular compartment, although few peritubular and interstitial cells were also stained. We also identified specific ETA and ETB receptor transcripts in human testis; ETA expression was more abundant than the ETB expression. Mathematical analysis of multiple self- and cross-competition studies among [125I]ET-1, [125I]ET-3, and analogues confirmed the presence of the ETA and ETB isoreceptors. In testicular homogenates, the ETA receptor was sevenfold more concentrated than the ETB receptor. In order to localize the receptors, we performed [125I]ET-1 autoradiography. Binding sites were mostly concentrated into the seminiferous tubules, although interstitial and peritubular myoid cells were also positive. Within the seminiferous tubules, [125I]ET-1 binding sites were confined to primary and secondary spermatocytes and early spermatids, whereas Sertoli cells were negative. We were unable to demonstrate the presence of functional ET receptors in ejaculated spermatozoa. Because ET-like immunoreactivity was present in Sertoli cells, we next asked whether authentic ET-1 is present in human seminal fluid and represents a good index for Sertoli cell function. Reverse-phase high-performance liquid chromatography analysis of ET-like immunoreactivity in seminal fluid indicated that most of the detected peptides correspond to the ET-1 precursor, big-ET-1. The seminal concentration of ET-like immunoreactivity was similar in normospermic, oligospermic, azoospermic, and vasectomized men, indicating that ETs are produced in different parts of the male genital tract and that they do not represent an useful tool for the diagnosis of male reproductive diseases. In conclusion, this study demonstrated, for the first time, the presence of ET-1 and its receptors in human testis.