171 research outputs found
Interaponeurosis shear strain modulates behavior of myotendinous junction of the human triceps surae.
Muscle fascicles insert into a sheet-like aponeurosis. Adjacent aponeuroses are structurally in contact with each other, and ultimately merge into a common tendon. Consequently, fascicle shortening in planes of tissue layers in adjacent compartments must cause sliding between aponeuroses parallel to the acting forces. In this study, we used velocity-encoded, phase-contrast, and water-saturated spin-lattice relaxation time-weighted imaging to identify and track fascicle and aponeurosis behaviors of human medial gastrocnemius (MG) and soleus (Sol) during 15° dorsiflexion to 30° plantarflexion contractions of the ankle. Interaponeurosis shear strain, which was defined as the relative displacement of the aponeurosis at the fascicle end points (insertion) of the MG and Sol, was an average of 1.35 ± 0.27% (range 1.12 ∼ 1.87%), indicating that the strain is greater in the aponeurosis of MG fascicle insertion than the Sol. The myotendinous junction (MTJ) displacement increased significantly with decreasing interaponeurosis shear strain (P < 0.05). The magnitude of interaponeurosis shear strain had significant correlation with the temporal difference between the time at which the peak aponeurosis displacement of the MG and Sol occurred (P < 0.05). Our model also indicated that theoretical MTJ displacement varies in relation to temporal difference: no temporal difference caused the largest MTJ displacement and presence of temporal differences indicated a reduction in MTJ displacement. Therefore, we concluded that interaponeurosis shear strain is a mechanism enabling individual muscle contraction and thus specific loading of the tendon and joint
Late Cenozoic Micropaleontologic Events in the Equatorial Pacific Sediments
A microbiostratigraphical investigation of five deep-sea sediment cores from the equatorial Pacific was carried out by utilizing planktonic foraminifers, radiolarians and calcareous nannoplankton. Several micropaleontologic events characterized by the first occurrence of taxa were found to provide reliable datum planes for stratigraphic correlation of post-Miocene sediments. These datum planes are : The Buccinosphaera invaginata Datum, Collosphaera tuberosa Datum, Globoquadrina conglomerata Datum, Pulleniatina obliquil-oculata Datum, Gephyrocapsa oceanica Datum, Gephyrocapsa caribbeanica Datum, Anthocyrtidium angulare Datum and Globorotalia (G.) truncatulinoides Datum, in downward sequence. These datum planes are related to the biostratigraphic zonations based on various microfossils, and further to the previously determined paleomagnetic stratigraphy. One new radiolarian species, Amphiropalum praeypsilon, is described
Acute and Prolonged Effects of Dermal Suction on Joint Range of Motion and Passive Muscle Stiffness: A Preliminary Study
This study aimed to investigate the acute and prolonged effects of dermal suction on joint range of motion (ROM) and passive muscle stiffness. Eight-minute dermal suction was prescribed for the quadriceps femoris in 15 participants. Hip extension ROM, knee flexion ROM, and passive muscle stiffness of the rectus femoris (RF) and vastus lateralis (VL) were measured before and immediately, 30 min, 60 min, 120 min, 24 h, and 48 h after dermal suction. Passive muscle stiffness was measured using shear wave elastography. Hip extension ROM significantly increased immediately (p = 0.032), 60 min (p = 0.029), and 120 min (p = 0.031) after dermal suction compared with before dermal suction; however, it was not significantly different at 30 min, 24 h, and 48 h after dermal suction (p > 0.05). Passive muscle stiffness of the RF and VL and knee flexion ROM did not significantly change at any measurement time compared with before dermal suction (p > 0.05). Our preliminary results suggest that dermal suction improves hip extension ROM immediately after dermal suction of the quadriceps femoris, followed by a return to the pre-prescription level 30 min after. However, the effect was prolonged for 120 min and disappeared before 24 h
EFFECT OF SHOCK LOADING ON FOOD PROCESSING
ABSTRACT In the food industry, it is hoping high value-aided product and the increase in efficiency of food processing. On the other hand, we get an experimental result that the load of the shock wave improves an extraction of food, and soften food. But, the safe and high efficiency pressure vessel for the processing is necessary to apply these technologies to the food processing field actually. Therefore, we are planning the development of the pressure vessel for food processing. The fundamental data of the shock loading to food are necessary in order to make suitable vessel. As for these data, it is variety the specifications required by the kind of food and effect to expect. We report the result that shock wave loading was done to various food
Gymnemic acids inhibit rabbit glyceraldehyde-3-phosphate dehydrogenase and induce a smearing of its electrophoretic band and dephosphorylation
AbstractGymnemic acids (GA) inhibited rabbit muscle glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity. Binding of GA to GAPDH was observed by surface plasmon resonance measurement. Incubation of GAPDH with GA induced a smearing of the GAPDH band in SDS–PAGE. The GA-induced smearing was diminished by prior incubation of GA with γ-cyclodextrin or by GA treatment with NAD. GA treatment did not affect the electrophoretic mobility of glucose-6-phosphate isomerase and dehydrogenase. GA treatment diminished the GAPDH band detected by an antibody to phosphoserine, but did not affect the phosphoserine bands of glucose-6-phosphate isomerase and dehydrogenase. These results indicated that GA specifically induced dephosphorylation of GAPDH
CHANGE IN MECHANICAL PROPERTIES OF TRICEPS SURAE MUSCLE-TENDON UNIT AND RACE PERFORMANCE AFTER 1 YEAR IN WELL TRAINED DISTANCE RUNNERS
The purpose of this study was to determine change in relationship between stiffness of triceps surae muscle-tendon unit and race performance after one year with continuous training in well trained long distance runners. For 9 long distance runners, official race record and stiffness indexes of both muscle and tendon were investigated in pre and post measurements (after one year). The race performance (1.9%), passive torque of ankle joint (13.2%), and muscle stiffness index (73.6%) increased significantly between pre and post. Although significant correlations were not found between increment of race performance and change in all parameters, 6 of the 9 athletes showed increments of both race performance and stiffness index of muscle tissue. These results suggest that an increment of stiffness of the ankle joint and triceps muscle could be related to improvement of race performance in distance running
Identifying Suspicious Regions of Covid-19 by Abnormality-Sensitive Activation Mapping
This paper presents a fully-automated method for the identification of
suspicious regions of a coronavirus disease (COVID-19) on chest CT volumes. One
major role of chest CT scanning in COVID-19 diagnoses is identification of an
inflammation particular to the disease. This task is generally performed by
radiologists through an interpretation of the CT volumes, however, because of
the heavy workload, an automatic analysis method using a computer is desired.
Most computer-aided diagnosis studies have addressed only a portion of the
elements necessary for the identification. In this work, we realize the
identification method through a classification task by using a 2.5-dimensional
CNN with three-dimensional attention mechanisms. We visualize the suspicious
regions by applying a backpropagation based on positive gradients to
attention-weighted features. We perform experiments on an in-house dataset and
two public datasets to reveal the generalization ability of the proposed
method. The proposed architecture achieved AUCs of over 0.900 for all the
datasets, and mean sensitivity and specificity . The method can also identify notable lesions pointed out in the
radiology report as suspicious regions.Comment: 10 pages, 3 figure
Gamma Band Neural Synchronization Deficits for Auditory Steady State Responses in Bipolar Disorder Patients
Periodic auditory click stimulation has been reported to elicit an auditory steady state response (ASSR). The ASSR has been suggested to reflect the efficiency of γ-amino butyric acid (GABA) inhibitory interneuronal activity. Although a potential role for GABAergic dysfunction has been previously proposed, the role of neural synchronization in the ASSR in people with bipolar disorder (BD) has received little attention. In the current study, we investigated ASSRs to 20 Hz, 30 Hz, 40 Hz and 80 Hz click trains in BD patients. A total of 14 (4 males) BD patients and 25 (10 males) healthy controls participated in this study. ASSRs were obtained using whole-head 306-channel magnetoencephalography to calculate, ASSR power values and phase locking factors (PLF). BD patients exhibited significantly reduced mean ASSR power and PLF values bilaterally at frequencies of 30, 40, and 80 Hz (p<0.05 for these frequencies). At 20 Hz, bipolar patients showed no significant reduction in mean ASSR power and PLF values. There was a significant negative correlation between 80 Hz-ASSR-power values obtained from the right hemisphere and scores on the Hamilton Depression Rating Scale (rho = −0.86, p = 0.0003). The current study showed reduced low and high gamma band ASSR power and PLF bilaterally with no significant beta band ASSR reduction in BD patients. BD patients are characterized by deficits in gamma band oscillations, which may be associated with GABA inhibitory interneuronal activity dysfunction
Jun Dimerization Protein 2 (JDP2), a Member of the AP-1 Family of Transcription Factor, Mediates Osteoclast Differentiation Induced by RANKL
Osteoclasts are multinucleated cells that resorb bones, and are derived from hematopoietic cells of the monocyte/macrophage lineage. The receptor activator of NF-κB ligand (RANKL, also called ODF/TRANCE/OPGL) stimulates both osteoclast differentiation from osteoclast progenitors and activation of mature osteoclasts. To identify genes responsible for osteoclast differentiation, we used a molecular indexing technique. Here, we report a clone of one of these genes whose transcription is induced by soluble RANKL (sRANKL) in both the RAW264.7 cells of the mouse macrophage cell line and the mouse primary bone marrow cells. The predicted protein was found to be a mouse homologue of Jun dimerization protein 2 (JDP2), a member of the AP-1 family of transcription factors, containing a basic region-leucine zipper motif. Transient transfection experiments revealed that overexpression of JDP2 leads to activation of both tartrate-resistant acid phosphatase (TRAP) and cathepsin K gene promoters in RAW264.7 cells. Infection of mouse primary bone marrow cells with retroviruses expressing JDP2-facilitated sRANKL-mediated formation of TRAP-positive multinuclear osteoclasts. Importantly, antisense oligonucleotide to JDP2 strongly suppressed sRANKL-induced osteoclast formation of RAW264.7 cells. Our findings suggest that JDP2 may play an important role in the RANK-mediated signal transduction system, especially in osteoclast differentiation
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