Presented here is the fabrication and characterization of a tunable microfluidic check valve for use in marine nutrient sensing. The ball-style valve makes use of a rare-earth permanent magnet, which exerts a pulling force to ensure it remains passively sealed until the prescribed cracking pressure is met. By adjusting the position of the magnet, the cracking pressure is shown to be customizable to meet design requirements. Further applicability is shown by integrating the valve into a poly(methyl methacrylate) (PMMA) lab-on-chip device with an integrated optical absorbance cell for nitrite detection in seawater. Micro-milling is used to manufacture both the valve and the micro-channel structures. The valve is characterized up to a flow rate of 14 mL min and exhibits low leakage rates at high back pressures (<2 µL min at ~350 kPa). It is low cost, requires no power, and is easily implemented on microfluidic platforms.
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http://dx.doi.org/10.3390/s19214619 | DOI Listing |
Sci Rep
January 2025
College of Water Conservancy and Civil Engineering, Xinjiang Agricultural University, Urumqi, China.
A A Pract
December 2024
From the Department of Anesthesiology and Critical Care, All India Institute of Medical Sciences (AIIMS), Rishikesh, Uttarakhand, India.
The circle breathing system enables rebreathing using a carbon dioxide absorbent. This case report presents a rare incident of ventilation failure in a 30-year-old male patient due to a broken unidirectional valve in a soda lime canister. Despite the anesthesia machine passing automated checks, a mechanical blockage from caked soda lime in the inner inspiratory chamber led to insufficient tidal volume delivery.
View Article and Find Full Text PDFBMJ Case Rep
November 2024
Anesthesiology, Unidade Local de Saude de Coimbra, Coimbra, Portugal.
Hybrid procedures offer a promising solution for complex cases where open surgery is high risk, relying on the collaboration of anaesthesiologists, cardiac surgeons and interventional cardiologists. We present a male patient in his 70s with severe aortic stenosis, coronary artery disease, ascending aortic aneurysm and heart failure who underwent a hybrid cardiac procedure, including transcatheter aortic valve implantation, percutaneous coronary intervention of the right coronary artery and coronary artery bypass graft surgery. Through this hybrid intervention, involving a minimally invasive transcatheter and an open surgical procedure, the patient remained haemodynamically stable with minimal blood loss.
View Article and Find Full Text PDFZhonghua Yi Xue Za Zhi
November 2024
Heart Failure Care Unit, Heart Failure Center, Fuwai Hospital, Chinese Academy of Medical Sciences, National Center for Cardiovascular Diseases, Beijing100037, China.
To explore the feasibility of transthoracic cardiac shear wave elastography (SWE) for non-invasive quantitative measurement of myocardial stiffness in healthy volunteers (HV) and hypertrophic cardiomyopathy (HCM) patients, and analyze the relationship between myocardial shear wave velocity (SWV) and left ventricular diastolic function. A total of 16 HV who underwent health check-ups and 5 HCM patients who visited the Cardiology Outpatient Clinic at Fujian Medical University Affiliated Union Hospital from September 2022 to October 2023 were prospectively recruited. The SWE technique was used to measure SWV of the basal segment of the interventricular septum, including left ventricular long-axis myocardial shear wave velocity (LA-SWV) and short-axis myocardial shear wave velocity (SA-SWV).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2024
Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
Paper crafts, such as origami and kirigami, have become an interdisciplinary research theme transportable from art to science, and further to engineering. Kirigami-inspired architectural design strategies allow the establishment of three-dimensional (3D) mechanical linkages with unprecedented mechanical properties. Herein, we report a crystalline zeolitic imidazolate framework (ZIF), displaying folding mechanics based on a kirigami tessellation, originated from the double-corrugation surface (DCS) pattern.
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