127 research outputs found
On-glass optoelectronic platform for on-chip detection of DNA
Lab-on-chip are analytical systems which, compared to traditional methods, offer significant reduction of sample, reagent, energy consumption and waste production. Within this framework, we report on the development and testing of an optoelectronic platform suitable for the on-chip detection of fluorescent molecules. The platform combines on a single glass substrate hydrogenated amorphous silicon photosensors and a long pass interferential filter. The design of the optoelectronic components has been carried out taking into account the spectral properties of the selected fluorescent molecule. We have chosen the [Ru(phen)2(dppz)]2+ which exhibits a high fluorescence when it is complexed with nucleic acids in double helix. The on-glass optoelectronic platform, coupled with a microfluidic network, has been tested in detection of double-stranded DNA (dsDNA) reaching a detection limit as low as 10 ng/μL
Case study on economic return on investments for safety and emergency lighting in road tunnels
While planning a double-hole road tunnel with a length higher than one km, it is important to pay attention to the safety factor if an accident occurs. If there is a power outage, in order to avoid critical situations that could jeopardize the safety of the people present (facilitating the stream coming out from the tunnel and the arrival of the emergency personnel), it is really important to guarantee uninterrupted lighting of roadways, mandatory emergency lay-bys, and ways of escape. Uninterrupted service of the lighting systems supply must be guaranteed, in accordance with the current regulations, through the exertion of UPS (Uninterruptible Power Supply) and power units. During tunnel construction, such devices represent a cost that must be amortized. In this case study, which takes into consideration a section of a road tunnel characterized by emergency lay-bys and ways of escape, emergency and security lighting were planned and installation and management costs were evaluated. The goal of this research was the creation of a cash flow thanks to the energy generated by photovoltaic panels, in a way that the service life of the system (25 years) coincided with the amortization of the costs of the backup electrical equipment installation (complying with the regulations). The possibility of over-dimensioning the UPS and providing it with a proper photovoltaic panel surface (235 kWp) to generate and exchange electric energy with the grid was taken into consideration
Integration of amorphous silicon balanced photodiodes and thin film heaters for biosensing application
This work presents the development and testing of an integrated system for on-chip detection of thermochemiluminescent biomolecules. The activation energy of the reaction is provided by a transparent structure of thin film heaters deposited on one side of a glass substrate. Light, passing through the substrate, reaches an array of amorphous silicon differential structure deposited on the opposite side of the glass substrate. The structure is designed to perform differential current measurements between a light- shielded diode, whose current is sensitive only to temperature, and a photosensor, sensitive to both incident light and temperature. The device therefore balances the thermal variations of the photodiode current and reduces the dark-current noise. These features make the presented system very appealing as highly miniaturized micro-analytical devices for biosensing applications
Computational Fluid Dynamic Modelling of Thermal Periodic Stabilized Regime in Passive Buildings
The periodic stabilized regime is the condition where the temperature of each point of a certain environment varies following a periodic law. This phenomenon occurs in many practical applications, such as passive or ancient buildings not equipped with Heating, Ventilating and Air Conditioning HVAC systems and located in latitudes where the temperature greatly varies with Earth's daily cycles. Despite that, the study of transient phenomena is often simplified, i.e., considering negligible the thermal response of the indoor microclimate. An exact solution to enclosures whose microclimate is free to evolve under a periodic stabilized regime does not exist nowadays, also from an analytical point of view. The aim of this study is to parametrically analyze the thermal variations inside a room when a transient periodic temperature is applied on one side. The phenomenon has been numerically studied through Computational Fluid Dynamics (CFD) and analytically validated using a function that reproduces the daily variation of the outdoor temperature. The results of this research would lay the groundwork to develop analytical correlations to solve and predict the thermal behavior of environments subject to a periodic stabilized regime
Intellectual Disability and Brain Creatine Deficit: Phenotyping of the Genetic Mouse Model for GAMT Deficiency
none9noGuanidinoacetate methyltransferase deficiency (GAMT-D) is one of three cerebral creatine (Cr) deficiency syndromes due to pathogenic variants in the GAMT gene (19p13.3). GAMT-D is characterized by the accumulation of guanidinoacetic acid (GAA) and the depletion of Cr, which result in severe global developmental delay (and intellectual disability), movement disorder, and epilepsy. The GAMT knockout (KO) mouse model presents biochemical alterations in bodily fluids, the brain, and muscles, including increased GAA and decreased Cr and creatinine (Crn) levels, which are similar to those observed in humans. At the behavioral level, only limited and mild alterations have been reported, with a large part of analyzed behaviors being unaffected in GAMT KO as compared with wild-type mice. At the cerebral level, decreased Cr and Crn and increased GAA and other guanidine compound levels have been observed. Nevertheless, the effects of Cr deficiency and GAA accumulation on many neurochemical, morphological, and molecular processes have not yet been explored. In this review, we summarize data regarding behavioral and cerebral GAMT KO phenotypes, and focus on uncharted behavioral alterations that are comparable with the clinical symptoms reported in GAMT-D patients, including intellectual disability, poor speech, and autistic-like behaviors, as well as unexplored Cr-induced cerebral alterations.openRossi, Luigia; Nardecchia, Francesca; Pierigè, Francesca; Ventura, Rossella; Carducci, Claudia; Leuzzi, Vincenzo; Magnani, Mauro; Cabib, Simona; Pascucci, TizianaRossi, Luigia; Nardecchia, Francesca; Pierigè, Francesca; Ventura, Rossella; Carducci, Claudia; Leuzzi, Vincenzo; Magnani, Mauro; Cabib, Simona; Pascucci, Tizian
CFD Analysis of Urban Canopy Flows Employing the V2F Model: Impact of Different Aspect Ratios and Relative Heights
Computational fluid dynamics (CFD) is currently used in the environmental field to simulate flow and dispersion of pollutants around buildings. However, the closure assumptions of the turbulence usually employed in CFD codes are not always physically based and adequate for all the flow regimes relating to practical applications. The starting point of this work is the performance assessment of the V2F (i.e., v2¯ − f) model implemented in Ansys Fluent for simulating the flow field in an idealized array of two-dimensional canyons. The V2F model has been used in the past to predict low-speed and wall-bounded flows, but it has never been used to simulate airflows in urban street canyons. The numerical results are validated against experimental data collected in the water channel and compared with other turbulence models incorporated in Ansys Fluent (i.e., variations of both k-ε and k-ω models and the Reynolds stress model). The results show that the V2F model provides the best prediction of the flow field for two flow regimes commonly found in urban canopies. The V2F model is also employed to quantify the air-exchange rate (ACH) for a series of two-dimensional building arrangements, such as step-up and step-down configurations, having different aspect ratios and relative heights of the buildings. The results show a clear dependence of the ACH on the latter two parameters and highlight the role played by the turbulence in the exchange of air mass, particularly important for the step-down configurations, when the ventilation associated with the mean flow is generally poor
An all-glass microfluidic network with integrated amorphous silicon photosensors for on-chip monitoring of enzymatic biochemical assay
A lab-on-chip system, integrating an all-glass microfluidics and on-chip optical detection, was developed and tested. The microfluidic network is etched in a glass substrate, which is then sealed with a glass cover by direct bonding. Thin film amorphous silicon photosensors have been fabricated on the sealed microfluidic substrate preventing the contamination of the micro-channels. The microfluidic network is then made accessible by opening inlets and outlets just prior to the use, ensuring the sterility of the device. The entire fabrication process relies on conventional photolithographic microfabrication techniques and is suitable for low-cost mass production of the device. The lab-on-chip system has been tested by implementing a chemiluminescent biochemical reaction. The inner channel walls of the microfluidic network are chemically functionalized with a layer of polymer brushes and horseradish peroxidase is immobilized into the coated channel. The results demonstrate the successful on-chip detection of hydrogen peroxide down to 18 mu M by using luminol and 4-iodophenol as enhancer agent
Targeting mGlu5 metabotropic glutamate receptors in the treatment of cognitive dysfunction in a mouse model of phenylketonuria
We studied group-I metabotropic glutamate (mGlu) receptors in Pah(enu2) (ENU2) mice, which mimic the genetics and neurobiology of human phenylketonuria (PKU), a metabolic disorder characterized, if untreated, by autism, and intellectual disability (ID). Male ENU2 mice showed increased mGlu5 receptor protein levels in the hippocampus and corpus striatum (but not in the prefrontal cortex) whereas the transcript of the mGlu5 receptor was unchanged. No changes in mGlu1 receptor mRNA and protein levels were found in any of the three brain regions of ENU2 mice. We extended the analysis to Homer proteins, which act as scaffolds by linking mGlu1 and mGlu5 receptors to effector proteins. Expression of the long isoforms of Homer was significantly reduced in the hippocampus of ENU2 mice, whereas levels of the short Homer isoform (Homer 1a) were unchanged. mGlu5 receptors were less associated to immunoprecipitated Homer in the hippocampus of ENU2 mice. The lack of mGlu5 receptor-mediated long-term depression (LTD) in wild-type mice (of BTBR strain) precluded the analysis of hippocampal synaptic plasticity in ENU2 mice. We therefore performed a behavioral analysis to examine whether pharmacological blockade of mGlu5 receptors could correct behavioral abnormalities in ENU2 mice. Using the same apparatus we sequentially assessed locomotor activity, object exploration, and spatial object recognition (spatial novelty test) after displacing some of the objects from their original position in the arena. Systemic treatment with the mGlu5 receptor antagonist, MPEP (20 mg/kg, i.p.), had a striking effect in the spatial novelty test by substantially increasing the time spent in exploring the displaced objects in ENU2 mice (but not in wild-type mice). These suggest a role for mGlu5 receptors in the pathophysiology of ID in PKU and suggest that, also in adult untreated animals, cognitive dysfunction may be improved by targeting these receptors with an appropriate therapy
Missense PDSS1 mutations in CoenzymeQ10 synthesis cause optic atrophy and sensorineural deafness
CoenzymeQ10 is one of the main cellular antioxidants and an essential lipid involved in numerous cell reactions, such as energy production and apoptosis modulation. A large number of enzymes are involved in CoQ10 biosynthesis. Mutations in the genes encoding for these enzymes cause a CoQ10 deficiency, characterized by neurological and systemic symptoms. Here we describe two young sisters with sensorineural deafness followed by optic atrophy, due to a novel homozygous pathogenic variant in PDSS1. The visual system seems to be mainly involved when the first steps of CoQ10 synthesis are impaired (PDSS1, PDSS2, and COQ2 deficiency)
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