Relaxation Delay
Relaxation Delay - Related Videos
07:05
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2023
Source: Laboratory of Jonathan Flombaum—Johns Hopkins University Human memory is limited. Throughout most of its history, experimental psychology has focused on investigating the discrete, quantitative limits of memory—how many individual pieces of information a person can remember. Recently, experimental psychologists have also become interested in more qualitative limits—how precisely is information stored? The concept of memory precision can be both intuitive and elusive at once. It is...
01:29
Relaxation of Skeletal Muscles
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2024
The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions. When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
07:47
Measuring Delay Discounting in Humans Using an Adjusting Amount Task
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Cited by 55 •
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Delay discounting refers to a decline in the value of a reward when it is delayed relative to when it is immediately available. We outline a computer-based delay discounting task that is easy to implement and allows for the quantification of the degree of delay discounting in human participants.
07:51
Mesenteric Artery Contraction and Relaxation Studies Using Automated Wire Myography
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Cited by 37 •
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An automated myography method for force measurements in isolated mesenteric arteries is described. It employs a Mulvany-Halpern Auto Dual Wire Myograph 510A to determine responses to phenylephrine and extracellular calcium. The method allows consistent determination of isometric responses to agonists in small vessels of diameters of 60 - 300 μm, independently.
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Classification of Skeletal Muscle Relaxants
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2023
Skeletal muscle relaxants are a group of drugs that can reduce muscle stiffness and induce temporary paralysis to relieve pain. These agents can act centrally to reduce muscle tone or spasms in painful conditions such as multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), or spinal injuries; they are called antispasmodics or spasmolytics. Peripherally acting skeletal muscle relaxants interfere with the neurotransmission at the neuromuscular end plate to induce paralysis during...
FAQs
T1 relaxation time determines how much longitudinal magnetization returns before the next excitation. A delay that is too short leaves part of the spin system unrecovered, so the resulting signal can be weaker than expected. Because recovery depends on energy exchange with the surroundings, T1 behavior directly links the waiting period to spectral sensitivity and measurement reliability.
Shortening the delay increases the number of scans that can be collected in a given period, but it can also reduce signal intensity and produce unequal recovery. Those effects become important when peak areas are interpreted quantitatively. A longer interval generally improves recovery and accuracy, although the gain comes at the cost of a longer experiment.
Different components of a sample may not recover at the same rate because their relaxation behavior differs. Applying one insufficient delay can therefore affect their signals unequally, making relative peak intensities less dependable. This matters when comparing concentrations or evaluating mixtures, rather than simply determining whether individual resonances are present.
Selection begins with the intended measurement: rapid spectral acquisition favors a shorter compromise, whereas quantitative comparison favors more complete recovery. The relevant T1 relaxation behavior should guide that choice, particularly when samples contain components with different recovery characteristics. The final setting balances usable signal and quantitative reliability against the total time available for data collection.
During an experiment, the delay is inserted between successive excitation pulses or scans. The instrument then waits before the next excitation, allowing longitudinal magnetization to recover toward its equilibrium level. Repeating this timing consistently helps ensure that differences in peak intensity reflect the sample and measurement design, rather than uncontrolled variation in recovery.
The setting becomes especially important when NMR spectra support concentration comparisons or other quantitative interpretations. Longer delays can make those measurements more reliable by allowing greater signal recovery, while shorter settings may be acceptable when speed is the primary concern. Samples containing components with contrasting relaxation behavior require particular caution during interpretation.