An experiment is conducted in a rectangular channel obstructed by a transverse line of four inclined cylindrical rods. The pressure on the surface of a central rod and the pressure drop through the channel are measured varying the inclination angle of the rods. Three assemblies of rods with different diameters are tested. The measurements were analyzed applying momentum conservation principles and semi-empirical considerations. Several invariant dimensionless groups of parameters relating the pressure at key locations of the system with characteristic dimensions of the rods are produced. It was found that the independence principle holds for most of the Euler numbers characterizing the pressure at different locations, that is, the group is independent of the inclination angle provided that the inlet velocity projection normal to the rods is used to non-dimensionalize the pressure. The resulting semi-empirical correlations can be useful for designing similar hydraulic units.
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http://dx.doi.org/10.1038/s41598-022-10204-0 | DOI Listing |
BMC Med Genomics
January 2025
Department of Surgery, Faculty of General of Medicine, Koya University, Koya, Kurdistan Region - F.R., KOY45, Iraq.
Background: During mammalian spermatogenesis, the cytoskeleton system plays a significant role in morphological changes. Male infertility such as non-obstructive azoospermia (NOA) might be explained by studies of the cytoskeletal system during spermatogenesis.
Methods: The cytoskeleton, scaffold, and actin-binding genes were analyzed by microarray and bioinformatics (771 spermatogenic cellsgenes and 774 Sertoli cell genes).
Children (Basel)
January 2025
Connecticut Children's Medical Center-Hartford, 282 Washington Street, Hartford, CT 06106, USA.
Background/objectives: Determine the appropriate duration for multichannel sleep studies in former preterm infants with cardio-respiratory events beyond term equivalent age.
Hypothesis: A sleep study of 10 h will provide equivalent information compared to a 20-h study to detect significant cardio-respiratory abnormalities in this population.
Methods: Single-center retrospective study of 50 infants with 20-h sleep study.
Clocks Sleep
December 2024
Institute of Physics, Saratov State University, Astrahanskaia, 83, Saratov 410012, Russia.
This study involved 72 volunteers divided into two groups according to the apnea-hypopnea index (AHI): AHI>15 episodes per hour (ep/h) (main group, n=39, including 28 men, median AHI 44.15, median age 47), 0≤AHI≤15ep/h (control group, n=33, including 12 men, median AHI 2, median age 28). Each participant underwent polysomnography with a recording of 19 EEG channels.
View Article and Find Full Text PDFFunction (Oxf)
January 2025
Institute for Integrative Physiology, Department of Medicine, Pritzker School of Medicine, University of Chicago, Chicago, IL. 60637, USA.
Patients with obstructive sleep apnea (OSA) experience chronic intermittent hypoxia (CIH). OSA patients and CIH-treated rodents exhibit overactive sympathetic nervous system and hypertension, mediated through hyperactive carotid body (CB) chemoreflex. Activation of olfactory receptor 78 (Olfr78) by hydrogen sulfide (H2S) is implicated in CB activation and sympathetic nerve responses to CIH, but the downstream signaling pathways remain unknown.
View Article and Find Full Text PDFFront Mol Neurosci
January 2025
Department of Neurosurgery, Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
Hydrocephalus is a neurological condition caused by aberrant circulation and/or obstructed cerebrospinal fluid (CSF) flow after cerebral ventricle abnormal dilatation. In the past 50 years, the diagnosis and treatment of hydrocephalus have remained understudied and underreported, and little progress has been made with respect to prevention or treatment. Further research on the pathogenesis of hydrocephalus is essential for developing new diagnostic, preventive, and therapeutic strategies.
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