132 research outputs found
AZI23'UTR Is a New SLC6A3 Downregulator Associated with an Epistatic Protection Against Substance Use Disorders
Regulated activity of SLC6A3, which encodes the human dopamine transporter (DAT), contributes to diseases such as substance abuse disorders (SUDs); however, the exact transcription mechanism remains poorly understood. Here, we used a common genetic variant of the gene, intron 1 DNP1B sequence, as bait to screen and clone a new transcriptional activity, AZI23'UTR, for SLC6A3. AZI23'UTR is a 3' untranslated region (3'UTR) of the human 5-Azacytidine Induced 2 gene (AZI2) but appeared to be transcribed independently of AZI2. Found to be present in both human cell nuclei and dopamine neurons, this RNA was shown to downregulate promoter activity through a variant-dependent mechanism in vitro. Both reduced RNA density ratio of AZI23'UTR/AZI2 and increased DAT mRNA levels were found in ethanol-naive alcohol-preferring rats. Secondary analysis of dbGaP GWAS datasets (Genome-Wide Association Studies based on the database of Genotypes and Phenotypes) revealed significant interactions between regions upstream of AZI23'UTR and SLC6A3 in SUDs. Jointly, our data suggest that AZI23'UTR confers variant-dependent transcriptional regulation of SLC6A3, a potential risk factor for SUDs
A new diagnostic tool for brain disorders: extracellular vesicles derived from neuron, astrocyte, and oligodendrocyte
Brain disorders are the leading cause of disability worldwide, affecting people’s quality of life and causing economic burdens. The current clinical diagnosis of brain disorders relies solely on individual phenotypes and lacks accurate molecular biomarkers. An emerging field of research centers around extracellular vesicles (EVs), nanoscale membrane vesicles which can easily cross the blood–brain barrier. EVs in the blood are derived from various tissues, including the brain. Therefore, purifying central nervous system (CNS)-derived EVs from the blood and analyzing their contents may be a relatively non-invasive way to analyze brain molecular alterations and identify biomarkers in brain disorders. Recently, methods for capturing neuron-derived EVs (NDEs), astrocyte-derived EVs (ADEs), and oligodendrocyte-derived EVs (ODEs) in peripheral blood were reported. In this article, we provide an overview of the research history of EVs in the blood, specifically focusing on biomarker findings in six major brain disorders (Alzheimer’s disease, Parkinson’s disease, schizophrenia, bipolar disorder, depression, and autism spectrum disorder). Additionally, we discuss the methodology employed for testing CNS-derived EVs. Among brain disorders, Alzheimer’s disease has received the most extensive attention in EV research to date. Most studies focus on specific molecules, candidate proteins, or miRNAs. Notably, the most studied molecules implicated in the pathology of these diseases, such as Aβ, tau, and α-synuclein, exhibit good reproducibility. These findings suggest that CNS-derived EVs can serve as valuable tools for observing brain molecular changes minimally invasively. However, further analysis is necessary to understand the cargo composition of these EVs and improve isolation methods. Therefore, research efforts should prioritize the analysis of CNS-derived EVs’ origin and genome-wide biomarker discovery studies
Model Suggests Potential for Porites Coral Population Recovery After Removal of Anthropogenic Disturbance (Luhuitou, Hainan, South China Sea)
Population models are important for resource management and can inform about potential trajectories useful for planning purposes, even with incomplete monitoring data. From size frequency data on Luhuitou fringing reef, Hainan, South China Sea, a matrix population model of massive corals (Porites lutea) was developed and trajectories over 100 years under no disturbance and random disturbances were projected. The model reflects a largely open population of Porites lutea, with low local recruitment and preponderance of imported recruitment. Under no further disturbance, the population of Porites lutea will grow and its size structure will change from predominance of small size classes to large size classes. Therewith, total Porites cover will increase. Even under random disturbances every 10 to 20 years, the Porites population could remain viable, albeit at lower space cover. The models suggest recovery at Luhuitou following the removal of chronic anthropogenic disturbance. Extending the area of coral reef reserves to protect the open coral community and the path of connectivity is advisable and imperative for the conservation of Hainan’s coral reefs
An ex vivo preliminary investigation into the impact of parameters on tissue welding strength in small intestine mucosa-mucosa end-to-end anastomosis
Background: Tissue welding is an electrosurgical technique that can fuse tissue for small intestine anastomosis. However, limited knowledge exists on its application in mucosa-mucosa end-to-end anastomosis. This study investigates the effects of initial compression pressure, out-put power, and duration time on anastomosis strength ex vivo in mucosa-mucosa end-to-end anastomosis.Methods:Ex vivo porcine bowel segments were used to create 140 mucosa-mucosa end-to-end fusions. Different experimental parameters were employed for fusion, including initial com-pression pressure (50kPa–400 kPa), output power (90W, 110W, and 140W), and fusion time (5, 10, 15, 20 s). The fusion quality was measured by burst pressure and optical microscopes.Results: The best fusion quality was achieved with an initial compressive pressure between 200 and 250 kPa, an output power of 140W, and a fusion time of 15 s. However, an increase in output power and duration time resulted in a wider range of thermal damage. There was no significant difference between the burst pressure at 15 and 20 s (p > 0.05). However, a substantial increase in thermal damage was observed with longer fusion times of 15 and 20 s (p < 0.05).Conclusion: The best fusion quality for mucosa-mucosa end-to-end anastomosis ex vivo is achieved when the initial compressive pressure is between 200 and 250 kPa, the output power is approximately 140W, and the fusion time is approximately 15 s. These findings can serve as a valuable theoretical foundation and technical guidance for conducting animal experiments in vivo and subsequent tissue regeneration
Online Monitoring of Torpedo Car Shells Based on Equal Angle Scanning
Infrared sensors are being applied more and more widely in industrial production applications. Based on the theory of thermal radiation, this paper discusses the system design principle, temperature calibration method, and thermal image analysis method in detail. The system passed the measurement unit certification, showing that the field of view is 180°, the number of scanning points is 2048, the linear velocity is 10–100 Hz, the spatial resolution is 2.5 mrad, and the precision is ±1 °C. An online monitoring test of torpedo car was carried out in the steelmaking plant of Bao Steel. The results show that the system has strong anti-interference ability, stability, and reliability, and meets the application requirements of online monitoring
Evaluation and Validation of a Multiphysics Finite Element Model for a Piezoelectric Energy Harvester
This paper explores the applicability of using the multiphysics finite element method to model a piezoelectric energy harvester. The piezoelectric energy harvester under consideration consists of a stainless-steel cantilever beam attached by a piezoelectric ceramic patch. Two configurations are considered: one without a proof mass and one with a proof mass. Comsol Multiphysics software is used to simultaneously model three physics: the solid mechanics, the electrostatics, and the electrical circuit physics. Several key relationships are investigated to predict the behaviours of the piezoelectric energy harvester. The effects of the electrical load resistance and a proof mass on the performance of a piezoelectric energy harvester are evaluated. Experimental testing is conducted to validate the results found by the finite element model. Overall, the results from the finite element model closely match those from the experimental testing. It is found that increasing the load resistance of the piezoelectric energy harvester causes an increase in voltage across the load resistor, and matching the impedance yields the maximum power output. Increasing the proof mass reduces the fundamental frequency that results in an increase of the displacement transmissibility and the impedance matched resistance. The study shows that the multiphysics finite element method is effective to model piezoelectric energy harvesters.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Vibration Suppression and Energy Harvesting with a Non-traditional Vibration Absorber: Transient Responses
This paper focuses on vibration suppression and energy harvesting using a non-traditional vibration absorber referred to as model B. Unlike the traditional vibration absorber, model B has its damper connected between the absorber mass and ground. The apparatus used in the study consists of a cantilever beam attached by a mass at its free end and an electromagnetic energy harvester. The frequency tuning is achieved by varying the beam length while the damping tuning is realized by varying the harvester load resistance. The question addressed is how to achieve the best performance under transient responses. The optimum tuning condition for vibration suppression is based on the Stability Maximization Criterion (SMC). The performance of energy harvesting is measured by the percentage of the harvested energy to the input energy. A computer simulation is conducted. The results validate the optimum parameters derived by the SMC. There is a trade-off between vibration suppression and energy harvesting within the realistic ranges of the frequency tuning ratio and damping ratio. A multi-objective optimization is conducted. The results provide a guideline for obtaining a balanced performance. An experimental study is carried out. The results verify the main findings from the computer simulation. This study shows that the developed apparatus is capable of achieving simultaneous vibration suppression and energy harvesting under transient responses
Nonlinear Vibration Analysis of a Beam with a Breathing Crack
The phenomena of sub- and super-harmonic responses make up one of the prominent nonlinear characteristics of a beam with a breathing crack. In order to fully understand the behaviors of sub- and super-harmonic resonances, it is necessary to analyze the nonlinear vibration of a beam-like structure with a breathing crack. In this study, a new stiffness model that considers the influence of the partial crack closure is proposed to model the stiffness variation of the cracked beam. Based on the finite element model of a beam with a breathing crack, the multiple-scale method is proposed to analyze the nonlinear vibration of a cracked beam subjected to harmonic excitation, and the relation between the nonlinear vibration of the cracked beam and the system parameters is obtained. An experiment is conducted to validate the analytical results. The study shows that the nonlinear responses of a beam with a breathing crack are affected by both the structural parameters and the crack parameters
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