Evoking of action potentials (APs) in the trap of Dionaea muscipula Ellis at intervals shorter than 20 s caused a gradual decrease in the amplitude of the APs. At longer intervals the amplitude was constant. The calcium ionophore A23187 (1 μM) caused a considerable decrease of AP amplitude. Pretreatment of a segment of the Dionaea trap with cyclopiazonic acid (CPA), which is a specific inhibitor of the Ca-ATPase in the sarcoplasmic seticulum of animal cells and in ER vesicles isolated from plant cells, only slightly affected the amplitude when APs were evoked every 10 min; however, it caused a considerable decrease in the amplitude when the stimulation was repeated every 2 min. Assuming that APs increase the concentration of cytosolic Ca and the amplitude of AP depends on the gradient of Ca across the plasma membrane, the effect of CPA on the AP amplitude indicates that CPA inhibits the sequestration of Ca in Dionaea cells.
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http://dx.doi.org/10.1007/BF00262650 | DOI Listing |
J Appl Physiol (1985)
January 2025
Medical Physics Graduate Program, Duke University, Durham, North Carolina, United States.
Hyperpolarized Xe MRI/MRS enables quantitative mapping of function in lung airspaces, membrane tissue, and red blood cells (RBCs) within the pulmonary capillaries. The RBC signal also exhibits cardiogenic oscillations that are reduced in pre-capillary pulmonary hypertension (PH). This effect is obscured in patients with concomitant defects in transfer from airspaces to RBCs, which increase RBC oscillation amplitudes.
View Article and Find Full Text PDFFront Physiol
January 2025
Human Physiology Section of the Department of Pathophysiology and Transplantation, Università Degli Studi, Milano, Italy.
Introduction: Prolonged or strenuous exercise leads to a temporary decrease in muscle function and performance, which interferes with activity of both prime movers and postural muscles. This effect of fatigue has been reported both for single segment movements and for locomotion. However, little is known regarding the effects of fatigue on anticipatory postural adjustments (APAs) during gait initiation, a task in which the control of focal movement should be strictly coupled to a feedforward control of posture.
View Article and Find Full Text PDFFront Neurol
January 2025
Department of Neurology, Second Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.
Objective: To investigate changes of brain functional activity in patients with acute unilateral vestibulopathy (AUVP) using functional magnetic resonance imaging (fMRI).
Methods: We studied 32 AUVP patients and 30 healthy controls (HC) who received resting-state fMRI scanning. Methods of voxel-based amplitude of low-frequency fluctuation (ALFF) and seed-based functional connectivity (FC) were adopted to compare the difference in brain function between the two groups.
Microsc Res Tech
January 2025
Faculty of Dental Medicine, Grigore T. Popa University of Medicine and Pharmacy, Iasi, Romania.
One area of technological advancement has been the shift from stainless steel hand tools to nickel-titanium (Ni-Ti) rotary tools. This paper aims to perform an in vitro comparative study to evaluate the efficacy of five endodontic manual and rotary instruments such as Kerr files, Orodeka Plex V, ProTaper Flydent NiTi super files, and ProTaper Flydent NiTi super files in combination with an ultrasonic endodontic E3D Diamantata EMS scaler used for root canal shaping. The following aspects were highlighted: effective removal of smear layer (SL) from the dentinal tubules in the coronal 1/3, middle 1/3, and apical 1/3 of the root canal, appearance of cracks in the dentinal walls by SEM analysis, and highlighting of dentin mineral content and remnant debris by EDX analysis.
View Article and Find Full Text PDFSports Med Open
January 2025
Department of Physical Education and Sport Sciences, National Taiwan Normal University, 162, Section 1, Heping E. Road, Taipei, 106, Taiwan.
Background: Concurrent exercise (CE), an emerging exercise modality characterized by sequential bouts of aerobic (AE) and resistance exercise (RE), has demonstrated acute benefits on executive functions (EFs) and neuroelectric P3 amplitude. However, the effect of acute CE on inhibitory control, a sub-component of EFs, and P3 amplitude remains inconclusive. Moreover, exploring the mechanisms underlying the effects of acute exercise on EFs contributes to scientific comprehension, with lactate recognized as a crucial candidate positively correlated with EFs.
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