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1.
Micromachines (Basel) ; 14(4)2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37420952

RESUMO

In order to realize direct manufacturing of cavity inside metal without assembly, this paper investigates the mechanism of cavity manufacturing inside metals under compound acoustic fields. First, a local acoustic cavitations model is established to study the single bubble generation at fixed point in Ga-In metal droplets, which has a low melting point. Second, cavitation-levitation acoustic composite fields are integrated with the experimental system for simulation and experimentation. Through COMSOL simulation and experimentation, this paper expounds the manufacturing mechanism of metal internal cavity under acoustic composite fields. The key problem is to control the duration of the cavitation bubble by controlling the driving acoustic pressure's frequency and the magnitude of ambient acoustic pressure. Under the condition of composite acoustic fields, this method realizes the direct fabrication of cavity inside Ga-In alloy for the first time.

2.
J Colloid Interface Sci ; 636: 610-617, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36669454

RESUMO

The development of high-efficiency oxygen evolution reaction (OER) electrocatalysts is of great importance for electrolytic H2 generation. In this work, we report in-situ growth of MnCo2O4 nanoneedles and NiFeRu layered double hydroxide (LDH) nanosheets on nickel foam (NF) (MnCo2O4@NiFeRu-LDH/NF) that can function a highly efficient electrode toward electrocatalysis of OER. Such electrode demands an overpotential of as low as 205 mV to reach 10 mA cm-2 in alkaline electrolyte and can run stably over 120-hours continuous operation. A hybrid flow acid/alkali electrolyzer is set up by using the Pt/C as the acidic cathode coupling with the MnCo2O4@NiFeRu-LDH/NF as the alkaline anode, which only requires an applied voltage of 0.59 V and 0.94 V to attain an electrolytic current density of 10 mA cm-2 and 100 mA cm-2, respectively. The present work could push forward the further development of the electricity-saving electrolytic technique for H2 generation.

3.
Micromachines (Basel) ; 13(3)2022 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-35334706

RESUMO

Collecting sweat and monitoring its rate is important for determining body condition and further sweat analyses, as this provides vital information about physiologic status and fitness level and could become an alternative to invasive blood tests in the future. Presented here is a one-dollar, disposable, paper-based microfluidic chip for real-time monitoring of sweat rate. The chip, pasted on any part of the skin surface, consists of a skin adhesive layer, sweat-proof layer, sweat-sensing layer, and scale layer with a disk-shape from bottom to top. The sweat-sensing layer has an impressed wax micro-channel containing pre-added chromogenic agent to show displacement by sweat, and the sweat volume can be read directly by scale lines without any electronic elements. The diameter and thickness of the complete chip are 25 mm and 0.3 mm, respectively, permitting good flexibility and compactness with the skin surface. Tests of sweat flow rate monitoring on the left forearm, forehead, and nape of the neck of volunteers doing running exercise were conducted. Average sweat rate on left forearm (1156 g·m-2·h-1) was much lower than that on the forehead (1710 g·m-2·h-1) and greater than that on the nape of the neck (998 g·m-2·h-1), in good agreement with rates measured using existing common commercial sweat collectors. The chip, as a very low-cost and convenient wearable device, has wide application prospects in real-time monitoring of sweat loss by body builders, athletes, firefighters, etc., or for further sweat analyses.

4.
J Endocrinol ; 230(3): 347-55, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27432891

RESUMO

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant inherited syndrome characterized by multiple tumors in the parathyroid glands, endocrine pancreas and anterior pituitary. Recent clinical studies have revealed a strong association between MEN1 syndrome and the risk of developing diabetes mellitus; however, the underlying mechanisms remain unknown. In this study, heterozygous Men1 knockout (Men1(+/-)) mice were used as MEN1 models to investigate MEN1-associated glucose metabolic phenotypes and mechanisms. Heterozygous deficiency of Men1 in 12-month-old male mice induced fasting hyperglycemia, along with increased serum insulin levels. However, male Men1(+/-) mice did not show insulin resistance, as evidenced by Akt activation in hepatic tissues and an insulin tolerance test. Increased glucose levels following pyruvate challenge and expression of key gluconeogenic genes suggested increased hepatic glucose output in the male Men1(+/-) mice. This effect could be partly due to higher basal serum glucagon levels, which resulted from pancreatic islet cell proliferation induced by heterozygous loss of Men1 Taken together, our results indicate that fasted male Men1(+/-) mice, in the early stage of development of MEN1, display glucose metabolic disorders. These disorders are caused not by direct induction of insulin resistance, but via increased glucagon secretion and the consequent stimulation of hepatic glucose production.


Assuntos
Jejum/sangue , Hiperglicemia/sangue , Hiperglicemia/metabolismo , Neoplasia Endócrina Múltipla Tipo 1/metabolismo , Animais , Glucagon/metabolismo , Gluconeogênese/genética , Gluconeogênese/fisiologia , Heterozigoto , Hiperglicemia/genética , Resistência à Insulina/genética , Resistência à Insulina/fisiologia , Ilhotas Pancreáticas/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Camundongos Mutantes , Neoplasia Endócrina Múltipla Tipo 1/genética
5.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(2): 340-3, 2006 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-16826922

RESUMO

The present paper considers synthetically all kinds of factors affecting excitation spectrum under traditional measurement conditions of fluorescence matter in liquor using plasma atomic emission spectra. The input power, carrier gas flow and assistant gas flow for BEC of Na, V, Al were optimized by testing. The input power, carrier gas flow and assistant gas flow for Na are 950 W, 0.6 L x min(-1) and 1.0 L x min(-1), respectively. The input power, carrier gas flow and assistant gas flow for V are 1 150 W, 0.5 and 1.1 L x min(-1), respectively. The input power, carrier gas flow and assistant gas flow for Al are 1 150 W, 0.6 and 1.0 L x min(-1), respectively. The result shows that the method is sensitive, accurate, linear in a wide range and highly precise. The precision is between 1.7%-2.2%, the linear ranges are between 0-100 mg x L(-1) and recoveries are between 96%-105%.

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