2,496 research outputs found

    Demand controlled ventilation, case study on comfort and energy

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    The objectives of this research were to verify the operation of an installed system and to show the importance of a continuous monitoring of a facility installed in the south of Sweden and to compare the energy saving achievable with different ventilation systems with focus on keeping or improving the indoor comfort condition.The findings show the importance of continuous monitoring and the advantages of the choice of an advanced ventilation systemope

    Testicular torsion: preliminary results of in vitro cell stimulation using chorionic gonadotropin

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    Testicular torsion is a pathology that occurs in young males generally before the age of 25. Despite surgery representing the only effective approach, there is still a need to identify a marker that can predict whether a preserved testicle will be functional. In addition, no therapeutic approach is currently considered in the post-operative phase. Through an approach based on the in vitro culture of a tissue strictly linked to the testicle, the gubernaculum, we defined the healthy state of the organ and the possible responsiveness to a therapy used in the andrology field, chorionic gonadotropin (hCG). Firstly, we optimized a protocol to obtain viable cells starting from a small piece of gubernacular tissue harvested during surgery with the aim to amplify cells in vitro. Intriguingly, only for a patient whose testicle had been removed during surgery due to an excessive necrotic area, gubernacular cells were not able to grow in culture. These data support the possibility of exploiting the gubernaculum to evaluate the healthy state of the testicle. Then, as we demonstrate that gubernacular cells express a luteinizing hormone receptor, to which hCG is specific, we analyzed the cellular response to hCG treatment on in vitro cultured cells derived from patients affected by testicular torsion. Our study opens the way for the possibility of evaluating testicle wellbeing after derotation through in vitro culture of a small piece of gubernaculum together with predicting the response to the treatment with hCG, which can have a positive effect on cell proliferation and vascularization

    Dispersion curves of infinite laminate panels through a modal analysis of finite cylinders

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    This work presents an approach for using a modal analysis on an equivalent finite cylindrical model, to predict the elastic waves in infinite, isotropic or composite, panels. In the description of the infinite paths, an analogy, between the classical topologies of a straight line and a circumference, is exploited and tested. Different aspects, concerning the wavemode duality and the discretization and the needed radii of curvature, are investigated to frame the problem and test the robustness of the methodology. The analysis presents a well conditioned problem and solution for any propagation wave angle by transforming the original problem into a simple modal analysis

    The Emerging Role of Altered D-Aspartate Metabolism in Schizophrenia: New Insights From Preclinical Models and Human Studies

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    Besides D-serine, another D-amino acid with endogenous occurrence in the mammalian brain, D-aspartate, has been recently shown to influence NMDA receptor (NMDAR)-mediated transmission. D-aspartate is present in the brain at extracellular level in nanomolar concentrations, binds to the agonist site of NMDARs and activates this subclass of glutamate receptors. Along with its direct effect on NMDARs, D-aspartate can also evoke considerable L-glutamate release in specific brain areas through the presynaptic activation of NMDA, AMPA/kainate and mGlu5 receptors. D-aspartate is enriched in the embryonic brain of rodents and humans and its concentration strongly decreases after birth, due to the post-natal expression of the catabolising enzyme D-aspartate oxidase (DDO). Based on the hypothesis of NMDAR hypofunction in schizophrenia pathogenesis, recent preclinical and clinical studies suggested a relationship between perturbation of D-aspartate metabolism and this psychiatric disorder. Consistently, neurophysiological and behavioral characterization of Ddo knockout (Ddo−/−) and D-aspartate-treated mice highlighted that abnormally higher endogenous D-aspartate levels significantly increase NMDAR-mediated synaptic plasticity, neuronal spine density and memory. Remarkably, increased D-aspartate levels influence schizophrenia-like phenotypes in rodents, as indicated by improved fronto-hippocampal connectivity, attenuated prepulse inhibition deficits and reduced activation of neuronal circuitry induced by phencyclidine exposure. In healthy humans, a genetic polymorphism associated with reduced prefrontal DDO gene expression predicts changes in prefrontal phenotypes including greater gray matter volume and enhanced functional activity during working memory. Moreover, neurochemical detections in post-mortem brain of schizophrenia-affected patients have shown significantly reduced D-aspartate content in prefrontal regions, associated with increased DDO mRNA expression or DDO enzymatic activity. Overall, these findings suggest a possible involvement of dysregulated embryonic D-aspartate metabolism in schizophrenia pathophysiology and, in turn, highlight the potential use of free D-aspartate supplementation as a new add-on therapy for treating the cognitive symptoms of this mental illness

    d aspartate exerts an opposing role upon age dependent nmdar related synaptic plasticity and memory decay

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    In the present study, we demonstrated that D-aspartate acts as an _in vitro_ and _in vivo_ neuromodulatory molecule upon hippocampal NMDAR transmission. Accordingly, we showed that this D-amino acid, widely expressed during embryonic phase, was able to strongly influence hippocampus-related functions at adulthood. Thus, while up-regulated levels of D-aspartate increased LTP and spatial memory in four-month old adult mice, the prolonged deregulation of this molecule in thirteen-month old animals induced a substantial acceleration of age-dependent decay of synaptic plasticity and cognitive functions. Moreover, we highlighted a role for D-aspartate in enhancing NMDAR-dependent synaptic plasticity through an inducible "turn-on/turn-off-like mechanism". Strikingly, we also showed that D-aspartate, when administered to aged mice, strongly rescued their physiological synaptic decay and attenuated their cognitive deterioration. In conclusion, our data suggest a tantalizing hypothesis for which this in-embryo-occurring D-amino acid, might disclose plasticity windows in the aging brain

    Transvaginal ultrasound evaluation of the pelvis and symptoms after laparoscopic partial cystectomy for bladder endometriosis

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    Objective: To evaluate transvaginal sonography (TVS) findings after laparoscopic partial cystectomy for bladder endometriosis and to correlate postsurgical ultrasound findings with symptoms. Material and Methods: A retrospective study including women who underwent laparoscopic partial cystectomy for bladder endometriosis. Within 12 months after surgery, TVS examination was conducted in all patients to evaluate the bladder morphology, and the presence of any postsurgical sonographic findings of the pelvis. Painful symptoms were assessed using a visual analogue scale. Results: A total of 40 women were included. At the follow-up visit, 25 patients were receiving medical treatment while 15 had declined post-surgical therapy and had tried to conceive. The presence of bladder deep-infiltrating endometriosis (DIE) was found in nine (22.5%), fibrotic thickening of the bladder wall was found in 15 (37.5%), and normal bladder morphology was observed in 16 (40%). There was a correlation between anterior adenomyosis and bladder DIE, and fibrotic thickening of the bladder. Patients with TVS signs of bladder DIE and anterior adenomyosis suffered more dysmenorrhea and dysuria than patients with normal bladder. Conclusion: Post-operative TVS can detect the alteration of pelvis and could explain the causes of the persistence of symptoms. (J Turk Ger Gynecol Assoc 2022; 23: 145-53

    Persistent elevation of D-Aspartate enhances NMDA receptor-mediated responses in mouse substantia nigra pars compacta dopamine neurons

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    Dopamine neurons in the substantia nigra pars compacta regulate not only motor but also cognitive functions. NMDA receptors play a crucial role in modulating the activity of these cells. Considering that the amino-acid D-Aspartate has been recently shown to be an endogenous NMDA receptor agonist, the aim of the present study was to examine the effects of D-Aspartate on the functional properties of nigral dopamine neurons. We compared the electrophysiological actions of D-Aspartate in control and D-aspartate oxidase gene (Ddo(-/-)) knock-out mice that show a concomitant increase in brain D-Aspartate levels, improved synaptic plasticity and cognition. Finally, we analyzed the effects of L-Aspartate, a known dopamine neuron endogenous agonist in control and Ddo(-/-) mice. We show that D- and L-Aspartate excite dopamine neurons by activating NMDA, AMPA and metabotropic glutamate receptors. Ddo deletion did not alter the intrinsic properties or dopamine sensitivity of dopamine neurons. However, NMDA-induced currents were enhanced and membrane levels of the NMDA receptor GluN1 and GluN2A subunits were increased. Inhibition of excitatory amino-acid transporters caused a marked potentiation of D-Aspartate, but not L-Aspartate currents, in Ddo(-/-) neurons. This is the first study to show the actions of D-Aspartate on midbrain dopamine neurons, activating not only NMDA but also non-NMDA receptors. Our data suggest that dopamine neurons, under conditions of high D-Aspartate levels, build a protective uptake mechanism to compensate for increased NMDA receptor numbers and cell hyper-excitation, which could prevent the consequent hyper-dopaminergia in target zones that can lead to neuronal degeneration, motor and cognitive alterations

    Decreased Rhes mRNA levels in the brain of patients with Parkinson's disease and MPTP-treated macaques

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    In rodent and human brains, the small GTP-binding protein Rhes is highly expressed in virtually all dopaminoceptive striatal GABAergic medium spiny neurons, as well as in large aspiny cholinergic interneurons, where it is thought to modulate dopamine-dependent signaling. Consistent with this knowledge, and considering that dopaminergic neurotransmission is altered in neurological and psychiatric disorders, here we sought to investigate whether Rhes mRNA expression is altered in brain regions of patients with Parkinsonâ\u80\u99s disease (PD), Schizophrenia (SCZ), and Bipolar Disorder (BD), when compared to healthy controls (about 200 post-mortem samples). Moreover, we performed the same analysis in the putamen of non-human primate Macaca Mulatta, lesioned with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Overall, our data indicated comparable Rhes mRNA levels in the brain of patients with SCZ and BD, and their respective healthy controls. In sharp contrast, the putamen of patients suffering from PD showed a significant 35% reduction of this transcript, compared to healthy subjects. Interestingly, in line with observations obtained in humans, we found 27% decrease in Rhes mRNA levels in the putamen of MPTP-treated primates. Based on the established inhibitory influence of Rhes on dopamine-related responses, we hypothesize that its striatal downregulation in PD patients and animal models of PD might represent an adaptive event of the dopaminergic system to functionally counteract the reduced nigrostriatal innervation
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