201 research outputs found

    Testicular endocrine activity is upregulated by D-Aspartic acid in the green frog Rana esculenta

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    This study investigated the involvement of D-aspartic acid (D-Asp) in testicular steroidogenesis of the green frog Rana esculenta and its effect on stimulation of thumb pad morphology and glandular activity, a typical testosterone-dependent secondary sexual characteristic in this amphibian species. In the testis, D-Asp concentrations vary significantly during the reproductive cycle: they are low in pre- and post-reproductive periods, but reach peak levels in the reproductive period (140-236 nmol/g wet tissue). Moreover, the concentrations of D-Asp in the testis through the sexual cycle positively match the testosterone levels in the gonad and the plasma. The racemase activity evaluated during the cycle expresses its peak when D-Asp and testosterone levels are highest, that is, during the reproductive period, confirming the synthesis of D-Asp from L-Asp by an aspartate racemase. Short-term in vivo experiments consisting of a single injection of D-Asp (2.0 micro mol/g body weight) demonstrated that this amino acid accumulates significantly in the testis, and after 3 h its uptake is coupled with a testosterone increase in both testis and plasma. Moreover, within 18 h of amino acid administration, the D-Asp concentration in the testis decreased along with the testosterone titer to prestimulation levels. Other amino acids (L-Asp, D-Glu and L-Glu) used instead of D-Asp were ineffective, confirming that the significant increase in testicular testosterone was a specific feature of this amino acid. In long-term experiments, D-Asp had been administered chronically to frogs caught during the three phases of the reproductive cycle, inducing testosterone increase and 17beta-estradiol decrease in the gonad during the pre- and post-reproductive period, and vice versa during the reproductive period

    Preliminary numerical analysis of the seismic response of steel frames with masonry infills retrofitted by buckling-restrained braces

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    Existing steel moment-resisting frames in several seismic regions worldwide are often characterised by high vulnerability to earthquakes due to insufficient local and/or global ductility. Nowadays, it is of paramount importance to assess their response under strong motions and provide cost-effective retrofitting strategies. Amongst others, the seismic behaviour of these frames is often strongly affected by the presence of masonry infills which, from one side, if adequately distributed, beneficially contribute to the seismic resistance of the structure providing stiffness and strength to the frame, from the other side often experience a brittle behaviour and are very vulnerable to seismic actions. To this end, the H2020-INFRAIA-SERA project HITFRAMES (i.e., HybrId Testing of an Existing Steel Frame with Infills under Multiple EarthquakeS) experimentally evaluated a case study building representative of non-seismically designed European steel frames with masonry infills and investigated a possible retrofit strategy. This paper takes advantage of the experimental results of the HITFRAMES project to calibrate numerical models in OpenSees of a case study building which is analysed as bare, infilled and retrofitted frame with buckling-restrained braces (BRBs). The impact of masonry infills and BRB-retrofit is investigated by comparing the response of models with different configurations. The numerical results provide some insights on the ability of BRB-retrofit option in protecting not only the steel frames from experiencing critical damage during earthquakes but also the masonry infills and on the importance of using appropriate models for the masonry infills in the assessment procedures

    Low penetrance and effect on protein secretionof LGI1 mutations causing autosomal dominantlateral temporal epilepsy

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    Purpose: To describe the clinical and genetic findings of four families with autosomal dominant lateral temporal epilepsy. Methods: A personal and family history was obtained from each affected and unaffected subject along with a physical and neurologic examination. Routine electroencephalography and magnetic resonance imaging (MRI) studies were performed in almost all patients. DNAs from family members were screened for LGI1 mutations. The effects of mutations on Lgi1 protein secretion were determined in transfected culture cells. Key Findings: The four families included a total of 11 patients (two deceased), six of whom had lateral temporal epilepsy with auditory aura. Age at onset was in the second decade of life; seizures were well controlled by antiepileptic treatment and MRI studies were normal. We found two pathogenic LGI1 mutations with uncommonly low penetrance: the R136W mutation, previously detected in a sporadic case with telephone-induced partial seizures, gave rise to the epileptic phenotype in three of nine mutation carriers in one family; the novel C179R mutation caused epilepsy in an isolated patient from a family where the mutation segregated. Another novel pathogenic mutation, I122T, and a nonsynonymous variant, I359V, were found in the two other families. Protein secretion tests showed that the R136W and I122T mutations inhibited secretion of the mutant proteins, whereas I359V had no effect on protein secretion; C179R was not tested, because of its predictable effect on protein folding. Significance: These findings suggest that some LGI1 mutations may have a weak penetrance in families with complex inheritance pattern, or isolated patients, and that the protein secretion test, together with other predictive criteria, may help recognize pathogenic LGI1 mutations. KEY WORDS: Autosomal dominant lateral temporal epilepsy, LGI1, Mutation, Low penetrance, Protein secretion

    Stereochemical and Skeletal Diversity Arising from Amino Propargylic Alcohols

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    An efficient synthetic pathway to the possible stereoisomers of skeletally diverse heterocyclic small molecules is presented. The change in shape brought about by different intramolecular cyclizations of diastereoisomeric amino propargylic alcohols is quantified using principal moment-of-inertia (PMI) shape analysis.Chemistry and Chemical Biolog

    Where do you live? North versus Central-South differences in relation to Italian patients with oral lichen planus: a cross-sectional study from the SIPMO (Italian Society of Oral Pathology and Medicine)

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    Background Oral lichen planus (OLP) is an immune-mediated inflammatory chronic disease of the oral mucosa, with different patterns of clinical manifestations which range from keratotic manifestations (K-OLP) to predominantly non-keratotic lesions (nK-OLP). The aim of the study was to analyze the differences in the clinical, psychological profile and symptoms between Italian patients of the North and Central-South with K-OLP and nK-OLP. Methods 270 K-OLP and 270 nK-OLP patients were recruited in 15 Italian universities. The Numeric Rating Scale (NRS), Total Pain Rating Index (T-PRI), Hamilton Rating Scales for Depression and for Anxiety (HAM-D and HAM-A), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS) were administered. Results The Central-South K-OLP (CS-K-OLP) patients reported a higher frequency of pain/burning compared with the K-OLP patients of the North (N-K-OLP) with higher scores in the NRS and T-PRI (p value < 0.001**). The CS-K-OLP and the CS-nK-OLP patients showed higher scores in the HAM-D, HAM-A, PSQI and ESS compared with the Northern patients (p value < 0.001**). Multivariate logistic regression revealed that the NRS and T-PRI showed the greatest increase in the R2 value for the CS-K-OLP (DR2 = 9.6%; p value < 0.001**; DR2 = 9.7% p value < 0.001**; respectively) and that the oral symptoms (globus, itching and intraoral foreign body sensation) and PSQI showed the greatest increase in the R2 value for the CS-nK-OLP (DR2 = 5.6%; p value < 0.001**; DR2 = 4.5% p value < 0.001** respectively). Conclusions Pain and mood disorders are predominant in patients with OLP in the Central-South of Italy. Clinicians should consider that the geographical living area may explain the differences in oral symptoms and psychological profile in OLP

    Targeted Inactivation of Cerberus Like-2 Leads to Left Ventricular Cardiac Hyperplasia and Systolic Dysfunction in the Mouse

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    Previous analysis of the Cerberus like 2 knockout (Cerl2(-/-)) mouse revealed a significant mortality during the first day after birth, mostly due to cardiac defects apparently associated with randomization of the left-right axis. We have however, identified Cerl2-associated cardiac defects, particularly a large increase in the left ventricular myocardial wall in neonates that cannot be explained by laterality abnormalities. Therefore, in order to access the endogenous role of Cerl2 in cardiogenesis, we analyzed the embryonic and neonatal hearts of Cerl2 null mutants that did not display a laterality phenotype. Neonatal mutants obtained from the compound mouse line Cer2(-/-)Fundacao para a Ciencia e Tecnologia (FCT); IBB/CBME [PEst-OE/EQB/LA0023/2011]; FCT [SFRH/BD/62081/2009]info:eu-repo/semantics/publishedVersio

    Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel

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    Dark matter lighter than 10  GeV/c2 encompasses a promising range of candidates. A conceptual design for a new detector, DarkSide-LowMass, is presented, based on the DarkSide-50 detector and progress toward DarkSide-20k, optimized for a low-threshold electron-counting measurement. Sensitivity to light dark matter is explored for various potential energy thresholds and background rates. These studies show that DarkSide-LowMass can achieve sensitivity to light dark matter down to the solar neutrino fog for GeV-scale masses and significant sensitivity down to 10  MeV/c2 considering the Migdal effect or interactions with electrons. Requirements for optimizing the detector’s sensitivity are explored, as are potential sensitivity gains from modeling and mitigating spurious electron backgrounds that may dominate the signal at the lowest energies

    Study of cosmogenic activation above ground for the DarkSide-20k experiment

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    The activation of materials due to exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k, currently under construction at the Laboratori Nazionali del Gran Sasso, is a direct detection experiment for galactic dark matter particles, using a two-phase liquid-argon Time Projection Chamber (TPC) filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in 39Ar. Despite the outstanding capability of discriminating / background in argon TPCs, this background must be considered because of induced dead time or accidental coincidences mimicking dark-matter signals and it is relevant for low-threshold electron-counting measurements. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the experiment has been estimated to set requirements and procedures during preparation of the experiment and to check that it is not dominant over primordial radioactivity; particular attention has been paid to the activation of the 120 t of UAr used in DarkSide-20k. Expected exposures above ground and production rates, either measured or calculated, have been considered in detail. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. The activity of 39Ar induced during extraction, purification and transport on surface is evaluated to be 2.8% of the activity measured in UAr by DarkSide-50 experiment, which used the same underground source, and thus considered acceptable. Other isotopes in the UAr such as 37Ar and 3H are shown not to be relevant due to short half-life and assumed purification methods

    Study on cosmogenic activation above ground for the DarkSide-20k project

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    The activation of materials due to the exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k is a direct detection experiment for galactic dark matter particles, using a two-phase liquid argon time projection chamber filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in 39Ar. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the argon and other massive components of the set-up has been estimated; production of 120 t of radiopure UAr is foreseen. The expected exposure above ground and production rates, either measured or calculated, have been considered. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. Activation of titanium, considered in early designs but not used in the final design, is discussed. The activity of 39Ar induced during extraction, purification and transport on surface, in baseline conditions, is evaluated to be 2.8% of the activity measured in UAr from the same source, and thus considered acceptable. Other products in the UAr such as 37Ar and 3H are shown to not be relevant due to short half-life and assumed purification methods

    Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel

    Get PDF
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