In a machine for tensile tests the ultimate strength, stress and strain of the aorta ascendens of 47 female pigs (German landrace) at three different regions of the vessel wall were determined. The animals were fattened under identical conditions in a progeny testing station and slaughtered at the same living weight (102 +/- 2 kg). Weak regressions of body weight and age on parameters measured were nevertheless accounted for. The average elastin content of the aorta ascendens diminished with advancing age but was not significantly correlated to biomechanical properties of the three single samples. Maximum load, stress and modulus of vessel wall segment I (stamped out nearer to the heart) was greater than in sample II. These circumferential segments however exhibited highly stronger biomechanical resistance than sample III, which was stamped longitudinally. In samples I and II there was a negative correlation between thickness of the wall and ultimate tensile stress (N/mm2). Freezing of the material prior to test at -18degrees C for one week resulted in a significant rise in ultimate tensile strength and stress. The meaning of these findings for comparative angiology is discussed.
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http://dx.doi.org/10.1007/BF01851903 | DOI Listing |
Oper Neurosurg (Hagerstown)
January 2025
Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia, USA.
Adult spinal deformity comprises a heterogeneous group of disorders that primarily affects older patients and can have a significant negative affect on health-related quality of life. Operative treatment for adult spinal deformity typically entails posterior instrumented fusions that have demonstrated the potential to significantly improve health-related quality of life outcomes. However, until fusion is achieved, the instrumentation providing structural support is subject to repetitive cyclical loading that disproportionately fatigues high-stress areas and can result in instrumentation failure.
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December 2024
Prosthodontics and Implantology, Amrita School of Dentistry, Amrita Vishwa Vidyapeetham, Kochi, IND.
Purpose: Acrylic dentures fabricated using polymethyl methacrylate are subjected to either intraoral fatigue stress or extraoral impact stress, eventually forming microcracks and fractures. This limitation should be overcome by either modification in the acrylic resin material or in polymerization techniques. This study compares the impact strength and flexural strength of high-impact resin to conventional resin in short- and long-heat polymerization settings.
View Article and Find Full Text PDFHeliyon
December 2024
Department of Mechanics, Electrical Power and Computer, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Dissimilar laser welding of martensitic AISI 1060 carbon steel and Duplex Stainless Steel 2205 was performed based on an experimental and numerical study. The experiments were then conducted based on central composite design experiments (CCD) and analyzed via the response surface methodology (RSM) by considering the effect of laser welding process parameters (incident laser power, speed of welding, nozzle distance and deviation of laser beam) on the weld joint characterization. The experimental results showed that the laser power had a remarkable effect on the melt pool depth.
View Article and Find Full Text PDFFront Plant Sci
December 2024
Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy.
Transmembrane proteins (TMPs) are pivotal components of plant defence mechanisms, serving as essential mediators in the response to biotic stresses. These proteins are among the most complex and diverse within plant cells, making their study challenging. In spite of this, relatively few studies have focused on the investigation and characterization of TMPs in plants.
View Article and Find Full Text PDFAfr J Reprod Health
November 2024
Meng Research Institute, Changzhou Hospital of Traditional Chinese Medicine, Chang Zhou 213003, Jiangsu, China.
This was an original article, and mainly evaluated the impacts of Buzhong Yiqi decoction and biofeedback electrical stimulation on pelvic floor muscle strength and the quality of life in patients with postpartum stress urinary incontinence (PSUI). PSUI patients (total = 256) were randomly selected into a control group and study group. The control group adopted pelvic floor muscle rehabilitation training only while the study group added Buzhong Yiqi decoction and biofeedback electrical stimulation.
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