829 research outputs found
Antidepressive and anxiolytic effects of ostruthin, a TREK-1 channel activator
We screened a library of botanical compounds purified from plants of Vietnam for modulators of the activity of a two-pore domain K+ channel, TREK-1, and we identified a hydroxycoumarin-related compound, ostruthin, as an activator of this channel. Ostruthin increased whole-cell TREK-1 channel currents in 293T cells at a low concentration (EC50 = 5.3 μM), and also activity of the TREK-2 channel (EC50 = 3.7 mM). In contrast, ostruthin inhibited other K+ channels, e.g. human ether-à -go-go-related gene (HERG1), inward-rectifier (Kir2.1), voltage-gated (Kv1.4), and two-pore domain (TASK-1) at higher concentrations, without affecting voltage-gated potassium channel (KCNQ1 and 3). We tested the effect of this compound on mouse anxiety- and depression-like behaviors and found anxiolytic activity in the open-field, elevated plus maze, and light/dark box tests. Of note, ostruthin also showed antidepressive effects in the forced swim and tail suspension tests, although previous studies reported that inhibition of TREK-1 channels resulted in an antidepressive effect. The anxiolytic and antidepressive effect was diminished by co-administration of a TREK-1 blocker, amlodipine, indicating the involvement of TREK-1 channels. Administration of ostruthin suppressed the stress-induced increase in anti-c-Fos immunoreactivity in the lateral septum, without affecting immunoreactivity in other mood disorder-related nuclei, e.g. the amygdala, paraventricular nuclei, and dorsal raphe nucleus. Ostruthin may exert its anxiolytic and antidepressive effects through a different mechanism from current drugs
Object-Oriented Approach: Applying ISO 21001 at Vietnamese Higher Education Institutions
To evaluate whether an educational institution has quality or not, requires standards that reflect all the requirements of the complex relationships operating within the educational institution. At the same time, this standard must be recognized by all nations for it to apply widely. It is in this context that the ISO 21001:2018 series of standards was published. This standard mentioned three areas of activities that an educational organization must pay attention to: training, scientific research, and community service. They are also the main activities that the educational accreditation standards refer to. To meet the requirement of quality guarantee and enhancement, a higher education institution has to apply quality assurance norms in general and quality criteria on management systems. Putting the ISO 21001 quality standard into practice is the choice of Vietnamese educational institutions to ensure they meet the requirements for improving management system quality. There are a set of quality system standards for educational organizations to satisfy their specific needs. Not following the traditional approach as they apply other ISO standard systems, Vietnamese educational institutions have chosen an object-base approach, where the beneficiaries are related to the management system of the university. They then approach the PDCA cycle to build and implement an ISO 21001 quality management system. We found that, according to this orientation, the implementation processes might be ensured given that the quality thresholds set by the university are met in order to satisfy the demands of the learners and related stakeholders. The paper aims to analyze the approach of Vietnamese educational institutions in implementing ISO 21001 standards, and at the same time identify advantages and disadvantages in developing policies in the quality management system at educational institutions. The paper also gives recommendations that can be adjusted by management at other higher education institutions to improve quality assurance activities towards sustainable development.
Keywords: ISO 21001:2018, quality assurance, quality management system, PDCA (Plan-Do-Check-Act), sustainable developmen
Some Solutions to Help Students Enjoy Learning English More
When teaching a large class of students, the teacher's biggest concern is which method to use to partially satisfy the learning needs of the majority of students. Each class has its unique characteristics, different learning needs, and the same level of students between classes at Tan Trao University. Some methods work well for one class, but not for another. This concern becomes much greater when the level of the student and the level of the curriculum has quite a big difference. Teachers often have to add the function of "curriculum designer" for a particular class. In addition to teaching according to the school's general curriculum, teachers must prepare more types of exercises and support activities to help students become more interested in learning and learn English more effectively. In this research paper, the writer of this article would like to mention some solutions that I have applied to students of Kindergarten Class C K8 and their feedback on my solution
Utilizing Visual Stimuli to Foster Engagement Among English Speaking Skill Learners During Instructional Sessions
The utilization of imagery proves highly effective in stimulating interest and fostering motivation for learners during the process of honing English speaking skills. Through this approach, not only does it facilitate learners in easily conceptualizing and comprehending concepts visually, but it also provides a platform for them to discuss and articulate ideas with confidence and creativity. Imagery serves as a bridge between language and real-life experiences, thereby igniting learners' passion and curiosity, aiding in their rapid and effective progress in language acquisition. In the journey of refining English speaking skills, imagery transcends mere static pictures to become gateways to myriad worlds. When educators incorporate images into the classroom, they bring not only pictures but also emotions, stories, and even dreams. Each detail within an image serves as a key, unlocking the door to imagination, enabling learners to step into a rich world where language extends beyond words on paper to vibrant images within the mind. Through the integration of imagery, the learning process becomes vivid and captivating, transforming each lesson into an adventure, a voyage filled with exploration and anticipation. 
Dynamics of evoked and spontaneous calcium transients in synaptic boutons of neocortical pyramidal neurons
In response to an action potential (AP), a transient rise in the
intracellular calcium concentration ([Ca2+]i) causes transmitter
release from nerve terminals. As the spatiotemporal dynamics of
this calcium rise can affect the efficacy and plasticity of
synaptic connections, it is essential to understand their
determinants. To characterise factors that shape calcium
transients in neocortical synaptic boutons, layer 5 pyramidal
cells in the rat somatosensory cortex were filled through the
patch pipette with a fluorescent calcium indicator for the
measurement of [Ca2+]i.
For accurate calculation of [Ca2+]i from the fluorescence
intensity, the calcium binding affinities (Kd) of the indicators
were measured in vitro, in solutions that were similar to the
patch-clamp internal solution. These solutions were made with
various concentrations of calcium chloride, but a constant
concentration of a calcium buffer. The resultant free [Ca2+] was
measured with a calcium-selective macroelectrode. It was found
that the Kd values of the calcium indicators were considerably
different from those previously published or provided by the
manufacturers.
Two main determinants of the intracellular calcium dynamics are
the capacity of endogenous calcium buffers and the activity of
calcium sequestration mechanisms. By measuring the peak amplitude
of single AP-evoked calcium transients with different
concentrations of OGB-1 or OGB-6F, a value of 7 was estimated for
the calcium-binding ratio of endogenous buffers. Thus, in
response to a single AP and in the absence of exogenous buffers,
[Ca2+]i was raised by 5.3 microM, with a total change of
approximately 50 microM. The rate constant of calcium
sequestration (0.60 per s) was estimated from the slow decay time
constant of the measured transients. The initial fast decay did
not prolong when intracellular calcium uptake was inhibited, or
speed up during repetitive stimulation. These findings suggest
that calcium-induced calcium release (CICR), buffer saturation,
and a non-linear calcium transporter were not the main cause of
the bi-exponential decay. A 3D model of a bouton en passant
showed that diffusion of calcium into the axon was likely the
underlying mechanism. During high-frequency stimulation, CICR
contributed to a supralinear summation of [Ca2+]i.
Spontaneous increases in [Ca2+]i have been observed in several
nerve terminals. They have been implicated in a number of
cellular processes, including calcium homeostasis and spontaneous
transmitter release. Here, the high-affinity calcium indicator
OGB-1 was used to monitor small changes in [Ca2+]i. Spontaneous
calcium transients (sCaTs) were observed at a frequency of around
0.2 per min. The increase in [Ca2+]i associated with each sCaT
was 1.4–2.3 microM, in the absence of exogenous buffers. It was
hypothesised that sCaTs arose from calcium release from
presynaptic stores. In support of this, caffeine increased the
average frequency of sCaTs by approximately 90%. The amplitude
and kinetics of sCaTs identified in caffeine and in the control
condition were not different from each other, suggesting that the
majority of sCaTs might have been a result of calcium release
through ryanodine receptors. The functional consequence(s) of
sCaTs in neocortical synaptic boutons remains to be determined
DESIGNING A GEODATABASE MODEL FOR URBAN INFORMATION SYSTEM AT THE BASIC LEVEL (Case Study in Nguyen Du Ward, Hai Ba Trung District, Hanoi City)
Joint Research on Environmental Science and Technology for the Eart
Static and Dynamic Analysis of Piezoelectric Laminated Composite Beams and Plates
In this chapter, the mechanical behavior analysis of piezoelectric laminated composite beams and plates is influenced subjected to static, dynamic, and aerodynamic loads. Algorithm for dynamic, stability problem analysis and vibration control of laminated composite beams and plates with piezoelectric layers is presented. In addition, numerical calculations, considering the effect of factors on static, dynamic, and stability response of piezoelectric laminated composite beams and plates are also clearly presented. The content of this chapter can equip readers with the knowledge used to calculate the static, dynamic, and vibration control of composite beams, panels made of piezoelectric layers applied in the field different techniques
DISTRIBUTION OF USEFUL AND HARMFUL MICROORGANISMS IN SHRIMP AQUACULTURE WATER IN TIEN HAI COASTAL OF THAI BINH PROVINCE
Joint Research on Environmental Science and Technology for the Eart
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