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1.
Nanomaterials (Basel) ; 12(6)2022 Mar 16.
Article in English | MEDLINE | ID: mdl-35335795

ABSTRACT

Nanotechnology has widespread applications in sports; however, there are very few studies reporting the use of nanotechnology to enhance physical performance. We hypothesize that a natural-mineral-based novel nanomaterial, which was developed from Japanese hot springs, might overcome the limitations. We examined if it could enhance physical performance. We conducted a treadmill exercise test on 18 students of athletic clubs at Fukushima University, Japan, and measured heart rate, oxygen consumption, maximal oxygen consumption, CO2 production, and respiratory quotient 106 times in total. The results showed that the elevation of heart rate was significantly suppressed in the natural-mineral-based nanomaterial group, while no differences were observed in oxygen consumption, maximal oxygen consumption, CO2 production, and respiratory quotient between groups. To our knowledge, this result is the first evidence where an improvement of cardiovascular and pulmonary functions was induced by bringing a natural-mineral-based nanomaterial into contact with or close to a living body without pharmacological intervention or physical intervention. This could open new avenue of biomedical industries even in an eco-friendly direction. The precise mechanisms remain a matter for further investigation; however, we may assume that endothelial NO synthase, hemoglobin and endothelium-derived hyperpolarizing factor are deeply involved in the improvement of cardiovascular and pulmonary functions.

2.
Nanomaterials (Basel) ; 10(9)2020 Aug 29.
Article in English | MEDLINE | ID: mdl-32872395

ABSTRACT

There are currently no promising therapy strategies for either the treatment or prevention of novel coronavirus disease 2019 (COVID-19), despite the urgent need. In addition to respiratory diseases, vascular complications are rapidly emerging as a key threat of COVID-19. Existing nitric oxide (NO) therapies have been shown to improve the vascular system; however, they have different limitations in terms of safety, usability and availability. In light of this, we hypothesise that a natural-mineral-based novel nanomaterial, which was developed based on NO therapy, might be a viable strategy for the treatment and prevention of COVID-19. The present study examined if it could induce an increase of intravascular NO, vasodilation and the consequent increase of blood flow rate and temperature in a living body. The intravascular NO concentration in the hepatic portal of rats was increased by 0.17 nM over 35.2 s on average after its application. An ultrasonic Doppler flow meter showed significant increases in the blood flow rate and vessel diameter, but no difference in the blood flow velocity. These were corroborated by measurements of human hand surface temperature. To our knowledge, this result is the first evidence where an increase of intravascular NO and vasodilation were induced by bringing a natural-mineral-based nanomaterial into contact with or close to a living body. The precise mechanisms remain a matter for further investigation; however, we may assume that endothelial NO synthase, haemoglobin and endothelium-derived hyperpolarising factor are deeply involved in the increase of intravascular NO.

3.
Biorheology ; 54(2-4): 51-65, 2018.
Article in English | MEDLINE | ID: mdl-29355112

ABSTRACT

BACKGROUND: Prediction of thrombus formation at intact arterial walls under low shear flow conditions is clinically important particularly for better prognoses of embolisation in cerebral aneurysms. Although a new mathematical model for this purpose is necessary, little quantitative information has been known about platelet adhesion to intact endothelial cells. OBJECTIVE: The objective of this study is to measure the number of platelets adhering to intact endothelial cells with a focus upon the influence of the shear rate. METHODS: Endothelial cells disseminated in µ-slides were exposed to swine whole blood at different shear rates. Adenosine diphosphate (ADP) was used as an agonist. Adherent platelets were counted by means of scanning electron microscopy. RESULTS: At an ADP concentration of 1 µM, 20.8 ± 3.1 platelets per 900 µm2 were observed after 30-minute perfusion at a shear rate of 0.8 s-1 whereas only 3.0 ± 1.4 per 900 µm2 at 16.8 s-1. CONCLUSIONS: The number of adherent platelets is determined by a balance between the shear and the degree of stimulation by the agonist. At an ADP concentration of 1 µM, a limit to the shear rate at which platelets can adhere to intact endothelial cells is considered to be slightly higher than 16.8 s-1.


Subject(s)
Blood Platelets/physiology , Endothelial Cells/physiology , Platelet Adhesiveness , Animals , Blood Platelets/ultrastructure , Cell Count , Cells, Cultured , Equipment Design , Female , Microscopy, Electron, Scanning , Rheology/instrumentation , Rheology/methods , Swine
4.
Acta Obstet Gynecol Scand ; 90(8): 839-45, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21539521

ABSTRACT

OBJECTIVE: To study fetal systemic arterial stiffness in normal fetuses and compromised fetuses who had umbilical placental insufficiency (UPI). DESIGN: Prospective study. SETTING: University departments. SAMPLE: A total of 118 normal fetuses (21-40 weeks) and 55 fetuses (UPI group) with evidence of potential compromise (high umbilical artery pulsatility index). METHODS: A new real-time noninvasive measurement system based on a combined Doppler ultrasound and echo-tracking system was used as a measure of aortic/systemic arterial stiffness. The augmentation index (AI) of the fetal thoracic descending aorta was measured by using simultaneous measurements of diameter pulse and flow velocity waveforms. MAIN OUTCOME MEASURE: Augmentation index as a measure of stiffness. RESULTS: In normal fetuses, successful measurements for obtaining the AI were achieved in 103 of 118 fetuses. In the normal group, the AI, as well as placental resistance, decreased during the second trimester; in contrast, an increase in the AI was observed during the third trimester. Using the AI values from the normal group, the UPI group was divided into two subgroups: 29 fetuses with a normal AI and 26 fetuses with a high AI. The clinical outcome was significantly worse in the latter subgroup compared with the normal subgroup. CONCLUSIONS: The increase of afterload caused by a high umbilical placental resistance was associated with a decrease of aortic distensibility in the compromised fetuses, suggesting an alteration of aortic wall structure.


Subject(s)
Aorta/diagnostic imaging , Placenta/diagnostic imaging , Placental Insufficiency/diagnostic imaging , Umbilical Arteries/diagnostic imaging , Aorta/physiopathology , Blood Flow Velocity/physiology , Female , Humans , Placenta/physiopathology , Placental Insufficiency/physiopathology , Pregnancy , Pregnancy Trimester, Second , Pregnancy Trimester, Third , Ultrasonography, Prenatal , Umbilical Arteries/physiopathology
5.
Chem Commun (Camb) ; (1): 152-3, 2003 Jan 07.
Article in English | MEDLINE | ID: mdl-12611011

ABSTRACT

Cesium encapsulation inside single-walled carbon nanotubes (SWNTs) is for the first time realized by ion irradiation of SWNTs immersed in a magnetized alkali-metal plasma, the configuration of which is confirmed to comprise three varieties by field emission type transmission electron microscopy (FE-TEM) and scanning TEM (STEM) observation.

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