Growing CeO2 Nanoparticles Within the Nano-Porous Architecture of the SiO2 Aerogel

In this study, new CeO2-SiO2 aerogel nanocomposites obtained by controlled growth of CeO2 nanoparticles within the highly porous matrix of a SiO2 aerogel are presented. The nanocomposites have been synthesized via a sol-gel route, employing cerium (III) nitrate as the CeO2 precursor and selected surfactants to control the growth of the CeO2 nanoparticles, which occurs during the supercritical drying of the aerogels. Samples with different loading of the CeO2 dispersed phase, ranging from 5 to 15%, were obtained. The nanocomposites showed the morphological features typical of the SiO2 aerogels such as open mesoporosity with surface area values up to 430 m2·g−1. TEM and XRD characterizations show that nanocrystals of the dispersed CeO2 nanophase grow within the aerogel already during the supercritical drying process, with particle sizes in the range of 3 to 5 nm. TEM in particular shows that the CeO2 nanoparticles are well-distributed within the aerogel matrix. We also demonstrate the stability of the nanocomposites under high temperature conditions, performing thermal treatments in air at 450 and 900°C. Interestingly, the CeO2 nanoparticles undergo a very limited crystal growth, with sizes up to only 7 nm in the case of the sample subjected to a 900°C treatment

Advances in differential diagnosis and management of growth hormone deficiency in children

Growth hormone (GH) deficiency (GHD) in children is defined as impaired production of GH by the pituitary gland that results in growth failure. This disease might be congenital or acquired, and occurs in isolation or in the setting of multiple pituitary hormone deficiency. Isolated GHD has an estimated prevalence of 1 patient per 4000–10,000 live births and can be due to multiple causes, some of which are yet to be determined. Establishing the correct diagnosis remains key in children with short stature, as initiating treatment with recombinant human GH can help them attain their genetically determined adult height. During the past two decades, our understanding of the benefits of continuing GH therapy throughout the transition period from childhood to adulthood has increased. Improvements in transitional care will help alleviate the consequent physical and psychological problems that can arise from adult GHD, although the consequences of a lack of hormone replacement are less severe in adults than in children. In this Review, we discuss the differential diagnosis in children with GHD, including details of clinical presentation, neuroimaging and genetic testing. Furthermore, we highlight advances and issues in the management of GHD, including details of transitional care

Anti-Alcohol and Anxiolytic Properties of a New Chemical Entity, GET73

N-[(4-trifluoromethyl)benzyl]4-methoxybutyramide (GET73) is a newly synthesized compound structurally related to the clinically used, alcohol-substituting agent, gamma-hydroxybutyric acid (GHB). The present study was designed to assess whether GET73 may share with GHB the capacity to reduce alcohol intake in rats. Additionally, the effect of treatment with GET73 on anxiety-related behaviors and cognitive tasks in rats was investigated. A series of in vitro binding assays investigated the capacity of GET73 to bind to the GHB binding site and multiple other receptors. GET73 (10−9–10−3 M) failed to inhibit [3H]GHB binding at both high- and low-affinity GHB recognition sites in rat cortical membranes. GET73 displayed minimal, if any, binding at dopamine, serotonin, GABA, and glutamate receptors in membranes from different rat brain areas. Acute treatment with low-to-moderate, non-sedative doses of GET73 (5–50 mg/kg, i.g. or i.p.) (a) reduced alcohol intake and suppressed “alcohol deprivation effect” (a model of alcohol relapse) in selectively bred, Sardinian alcohol-preferring (sP) rats, (b) exerted anxiolytic effects in Sprague-Dawley (SD) and sP rats exposed to the Elevated Plus Maze test, and (c) tended to induce promnestic effects in SD rats exposed to a modified water version of the Hebb–Williams maze test. Although the mechanism of GET73 action is currently unknown, the results of the present study suggest that GET73 has a multifaceted pharmacological profile, including the capacity to reduce alcohol drinking and anxiety-related behaviors in rats

Appropriate management of growth hormone deficiency during the age of transition: an Italian Delphi consensus statement

No abstract availabl

An infrared thermography approach to evaluate the strength of a rock cliff

The mechanical strength is a fundamental characteristic of rock masses that can be empirically related to a number of properties and to the likelihood of instability phenomena. Direct field acquisition of mechanical information on tall cliffs, however, is challenging, particularly in coastal and alpine environments. Here, we propose a method to evaluate the compressive strength of rock blocks by monitoring their thermal behaviour over a 24-h period by infrared thermography. Using a drone-mounted thermal camera and a Schmidt (rebound) hammer, we surveyed granitoid and aphanitic blocks in a coastal cliff in south-east Sardinia, Italy. We observed a strong correlation between a simple cooling index, evaluated in the hours succeeding the temperature peak, and strength values estimated from rebound hammer test results. We also noticed different heatingcooling patterns in relation to the nature and structure of the rock blocks and to the size of the fractures. Although further validation is warranted in different morpho-lithological settings, we believe the proposed method may prove a valid tool for the characterisation of non-directly accessible rock faces, and may serve as a basis for the formulation, calibration, and validation of thermo-hydro-mechanical constitutive models

From: Trash to resource: Recovered-Pd from spent three-way catalysts as a precursor of an effective photo-catalyst for H2 production

The successful production of a nanostructured and highly dispersed Pd-TiO2 photo-catalyst, using [Pd(Me2dazdt)2](I3)2 (Me2dazdt = N,N\u2032-dimethyl-perhydrodiazepine-2,3-dithione) salt, obtained through the selective and safe recovery of palladium from model exhaust three-way catalysts (TWCs), is reported here. The photo-catalyst prepared by the impregnation/photo-reduction of palladium on the support showed improved performance in H2 production from methanol and in glycerol photo-reforming compared to reference photo-catalysts obtained from conventional Pd-salts. The reported results represent a case of successful palladium \u201crecovery and re-employment\u201d and thus constitute an example of green chemistry by providing, in one route, the environmentally friendly recovery of a critical metal and its employment in the renewable energy field

Relationship of CYP21A2 genotype and serum 17-hydroxyprogesterone and cortisol levels in a large cohort of Italian children with premature pubarche.

ObjectivePremature pubarche (PP) is the most frequent sign of nonclassic congenital adrenal hyperplasia (NCCAH) due to 21-hydroxylase deficiency in childhood. The aim of this study was to assess the relationship between the CYP21A2 genotype and baseline and ACTH-stimulated 17-hydroxyprogesterone (17-OHP) and cortisol serum levels in patients presenting with PP.Patients and methodsA total of 152 Italian children with PP were studied. Baseline and ACTH-stimulated 17-OHP and cortisol serum levels were measured and CYP21A2 gene was genotyped in all subjects.ResultsBaseline and ACTH-stimulated serum 17-OHP levels were significantly higher in NCCAH patients than in both heterozygotes and children with idiopathic PP (IPP). Of the patient population, four NCCAH patients (7.3%) exhibited baseline 17-OHP values &lt;2 ng/ml (6 nmol/l). An ACTH-stimulated 17-OHP cutoff level of 14 ng/ml (42 nmol/l) identified by the receiver-operating characteristics curves showed the best sensitivity (90.9%) and specificity (100%) in distinguishing NCCAH patients. This value, while correctly identifying all unaffected children, missed 9% of affected individuals. Cortisol response to ACTH stimulation was &lt;18.2 μg/dl (500 nmol/l) in 14 NCCAH patients (28%) and none of the heterozygotes or IPP children. Among the 55 NCCAH patients, 54.5% were homozygous for mild CYP21A2 mutations, 41.8% were compound heterozygotes for one mild and one severe CYP21A2 gene mutations, and 3.6% had two severe CYP21A2 gene mutations.ConclusionIn children with PP, baseline 17-OHP levels are not useful to rule out the diagnosis of NCCAH, which is accomplished by means of ACTH testing only. The different percentages of severe and mild CYP21A2 gene mutations found in PP children compared with adult NCCAH patients is an indirect evidence that the enzyme defect is under-diagnosed in childhood, and it might not lead to the development of hyperandrogenic symptoms in adulthood. Stress-dose glucocorticoids should be considered in patients with suboptimal cortisol response to ACTH stimulation.</jats:sec

Design, Performance and Series Production of Superconducting Trim Quadrupoles for the Large Hadron Collider

The Large Hadron Collider (LHC) will be equipped with several thousands of superconducting corrector magnets. Among the largest ones are the superconducting trim quadrupoles (MQTL). These twin-aperture magnets with a total mass of up to 1700 kg have a nominal gradient of 129 T/m at 1.9 K and a magnetic length of 1.3 m. Sixty MQTL are required for the LHC, 36 operating at 1.9 K in and 24 operating at 4.5 K. The paper describes the design features, and reports the measured quench performance and magnetic field quality of the production magnets. The MQTL magnet production is shared between CERN and industry. This sharing is simplified due to the modular construction, common to all twin-aperture correctors

Accuracy and limitations of the growth hormone (GH) releasing hormone-arginine retesting in young adults with childhood-onset GH deficiency

Background: Re-testing for GH secretion is needed to confirm the diagnosis of GH deficiency (GHD) after adult height achievement in childhood-onset GHD (COGHD). Aim: To define the cut-off of GH peak after retesting with GH-releasing hormone plus arginine (GHRHarg) in the diagnosis of permanent GHD in COGHD of different etiology. Patients and methods: Eighty-eight COGHD (median age 17.2 y), 29 idiopathic GHD (IGHD), 44 cancer survivors (TGHD) and 15 congenital GHD (CGHD) were enrolled in the study; 54 had isolated GHD (iGHD) and 34 had multiple pituitary hormone deficiencies (MPHD). All were tested with insulin tolerance test (ITT) and GHRHarg. IGHD with a GH response to ITT 656\ub5g/L were considered true negatives and served as the control group, and patients with a GH response &lt;6\ub5g/L as true positives. Baseline IGF-I was also measured. The diagnostic accuracy of GHRHarg testing and of IGF-I SDS in patients with GHD of different etiologies was evaluated by ROC analysis. Results: Forty-six subjects with a GH peak to ITT 656\ub5g/L and 42 with GH peak &lt;6 \ub5g/L showed a GH peak after GHRHarg between 8.8\u2013124\ub5g/L and 0.3\u201326.3\ub5g/L, respectively; 29 IGHD were true negatives, 42 were true positives and 17 with a high likelihood GHD showed a GH peak to ITT 656\ub5g/L. ROC analysis based on the etiology indicated the best diagnostic accuracy for peak GH cutoffs after GHRHarg of 25.3 \ub5g/L in CGHD, 15.7 in TGHD, and 13.8 in MPHD, and for IGF-1 SDS at 122.1 in CGHD, 121.5 in TGHD, and 121.9 in MPHD. Conclusions: Our findings indicate that the best cut-off for GH peak after retesting with GHRHarg changes according to the etiology of GHD during the transition age. Based on these results the diagnostic accuracy of GHRHarg remains questionable