Active Region
Active Region - Related Videos
03:03
High-Definition Transcranial Direct Current Stimulation for Activation of the Target Brain Region
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2025
Source: Chen, W., et al. Stimulation Location Determination using a 3D Digitizer with High-Definition Transcranial Direct Current Stimulation. J. Vis. Exp. (2019)This video demonstrates the procedure for delivering high-definition transcranial direct current stimulation (HD-tDCS) by accurately positioning electrodes using the 10–10 system, mapping their locations with a 3D digitizer, and applying stimulation to modulate neuronal activity in a targeted brain region.
01:03
IR Frequency Region: Fingerprint Region
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2024
IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the C=O, C=N, and C=C occur between 1600–1850 cm−1. The...
02:40
The Eukaryotic Promoter Region
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2020
The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are...
11:54
Measurement of BK-polyomavirus Non-Coding Control Region Driven Transcriptional Activity Via Flow Cytometry
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Cited by 1 •
2019
In this manuscript, a protocol is presented to perform FACS-based measurement of BK-polyomavirus transcriptional activity by using HEK293T cells transfected with a bidirectional reporter plasmid expressing tdTomato and eGFP. This method further allows to quantitatively determine the influence of novel compounds on viral transcription.
01:12
Regional Terms
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2023
Regional terms describe anatomy by dividing the body parts into different regions that contain structures involved in contributing similar functions. Using these terms helps increase the accurate description and identification of the particular region of interest or region affected by the disease. Primarily, the human body has two major regions, the axial and appendicular regions. The axial region comprises regions from the head to the abdomen and makes up the central body axis. In contrast,...
FAQs
In a BJT, the two junction biases establish the operating condition that makes collector current track base current. Forward bias at the base-emitter junction supplies the control relationship, while reverse bias at the base-collector junction preserves the condition needed for collector-current control. If either bias condition changes, the device can leave the intended amplification range.
Biasing establishes the operating point, while load-line analysis relates that point to the device's expected current and voltage behavior. Engineers use this combination to judge whether signal variations can remain within the active region. Doing so supports stable gain and a more linear signal response, while helping identify conditions associated with distortion or cutoff.
The controlling variable differs between the devices. For a BJT, collector current is primarily governed by base current under the specified junction biases. For a FET, gate voltage establishes the corresponding saturation-region condition by limiting channel behavior. Thus, engineers analyze different device mechanisms when designing amplifying stages.
To establish active-region operation in an amplifier, engineers apply suitable biasing and then use load-line analysis to examine the resulting operating condition. For a BJT, the check concerns forward bias at the base-emitter junction and reverse bias at the base-collector junction. For a FET, attention centers on gate voltage and channel limitation. The condition is then assessed for stable gain and linear response.
Leaving active-region operation can appear as distortion or cutoff in the circuit's response. Diagnosis therefore begins by examining the biasing conditions that set the device's operating range, followed by load-line analysis to determine whether the intended condition is maintained. This helps connect observed distortion or cutoff with the operating condition that produced it.
Active-region analysis supports three engineering tasks named in the topic: amplifier design, device modeling, and diagnosis of circuit behavior. In design, it helps target stable gain and linear response; in modeling, it provides an operating range for representing device behavior; in diagnosis, it gives engineers a framework for interpreting distortion or cutoff. These uses link device operation to practical circuit decisions.