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2.
Med Biol Eng Comput ; 59(5): 1151-1166, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33914219

RESUMO

The aim of this study was to explore changes in the microvascular tone as measured by laser Doppler flowmetry (LDF) and the microcirculation structure of the dorsal skin of rats with type 2 diabetes mellitus. The diabetic rat model was induced by a diet of high-sugar and high-lipid fodder combined with the injection of streptozotocin into the abdominal cavity. Depending on the interval between the development of diabetes and the experiments, the diabetic rats were subdivided into three groups. The evaluation of microvascular tone was based on the amplitude responses of the LDF signal fluctuations in the appropriate frequency range in the dorsal skin of the rats during a thermal test (at 42 °C). The nitric oxide (NO) level in plasma was also used as a marker of endothelial dysfunction. Changes in the microcirculation structure in the diabetic rats were estimated by measuring the microvascular density in the choke vessels of the dorsal skin of the rats. The experimental results with respect to red blood cell (RBC)-related parameters showed decreased hematocrit and hemoglobin levels and increased standard deviation of the width of the RBC distribution in three diabetic rats. The increasing fluctuation amplitudes diminished in the endothelial frequency range in response to the thermal test and this was accompanied by abnormal NO levels in plasma of the diabetic groups as compared with healthy rats. A significant reduction in the microvascular density of the choke vessels of the dorsal skin was found only in the diabetic group at the most advanced stage of diabetes in this experiment. Thus, we suggest that endothelial dysfunction occurs in diabetic rats and changes in the microcirculation structure of the dorsal skin occur in a later stage of diabetes development. A. Photograph of measurement method by using a LDF probe and heating device in the dorsal skin of the rat. B. Dorsal skin LDF signals of a healthy rat during the thermal stimuli test. (a) Blood flow signal record for the test. Wavelet filtration of blood flow signal in (b) myogenic range, (c) neurogenic range, and (d) endothelial range.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Animais , Fluxometria por Laser-Doppler , Microcirculação , Ratos , Fluxo Sanguíneo Regional , Pele
3.
PLoS One ; 16(3): e0246351, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33784316

RESUMO

The pressures to maintain a low-carbon economy makes green competitiveness (GC) a significant issue in China. It has been found that the development of Internet and E-commerce contributes significantly to GC of regional economy, yet there are still lack of quantitative investigation on their effects, which can be used to further guide the economic development. Therefore, this study constructs a new evaluation index for the green competitiveness of the regional manufacturing industry in China by introducing Internet application indicators and E-commerce development indexes into its evaluation system. The results show Jiangxi and Gansu moved upward significantly in the GC ranking over the period. The development of the Internet and E-commerce has the most significant impact on GC of regional manufacturing. The lack of green manufacturing capabilities and green innovation drivers led to a decline in the GC ranking of Liaoning, Tianjin, Guangxi and Heilongjiang. Finally, this study uses Moran's I index to investigate the spatial agglomeration effect of the green development of the manufacturing industry at the province level. The results show an increase in the GC of China's regional manufacturing industry, and the GC of manufacturing industry shows a significant agglomeration effect. Based on the above conclusions, the proposal to promote the balanced development of the GC of the manufacturing industry is proposed.


Assuntos
Comércio/métodos , Competição Econômica , Indústria Manufatureira/métodos , China , Desenvolvimento Econômico , Política Ambiental , Internet , Indústria Manufatureira/legislação & jurisprudência , Análise Espacial
4.
Sensors (Basel) ; 20(17)2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32825319

RESUMO

This paper presents a new algorithm based on model reference Kalman torque prediction algorithm combined with the sliding root mean square (SRMS). It is necessary to improve the accuracy and reliability of the pinch detection for avoiding collision with the height adjustable desk and accidents on users. Motors need to regulate their position and speed during the operation using different voltage by PWM (Pulse Width Modulation) to meet the requirement of position synchronization. It causes much noise and coupling information in the current sampling signal. Firstly, to analyze the working principle of an electric height adjustable desk control system, a system model is established with consideration of the DC (Direct Current) motor characteristics and the coupling of the system. Secondly, to precisely identify the load situation, a new model reference Kalman perdition method is proposed. The load torque signal is selected as a pinch state variable of the filter by comparing the current signal. Thirdly, to meet the need of the different loads of the electric table, the sliding root means square (SRMS) of the torque is proposed to be the criterion for threshold detection. Finally, to verify the effectiveness of the algorithm, the experiments are carried out in the actual system. Experimental results show that the algorithm proposed in this paper can detect the pinched state accurately under different load conditions.

5.
Microvasc Res ; 125: 103878, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31051161

RESUMO

It is pivotal that endothelium-dependent Nitric Oxide (NO) consumed by hemoglobin (Hb) inside red blood cells (RBCs) membrane, regulates the vascular tone. The whole processes of NO transport in vessel containing flowing RBCs is still not clear, such as NO production in endothelium, diffusion in plasma and consumption inside RBCs. In this work, the motion of RBCs in a microvessel is investigated by using immersed boundary lattice Boltzmann method (IB-LBM) first and the deformability of RBCs is expressed by using spring network model which is based on the minimum energy principle. Furthermore, the interaction between RBCs is considered. Based on the wall shear stress (WSS), NO production rate originated from endothelium was obtained by using a hyperbolic model. NO distribution inside the microvessel with multiple RBCs was computed by using immersed boundary finite difference method (IB-FDM). The result shows that a large (small) WSS exists at locations with a relatively wide(narrow) gap between the wall and cell. In terms of mass transfer, an increase of RBC membrane permeability leads to a decrease of NO concentration in the vessel and the surrounding endothelium significantly. In addition, with the increasing of hematocrit (Hct) value, NO concentration distribution in the whole vessel decreases both in the lumen and vascular wall. Finally, the thickness of RBCs-depleted layer gradually decreases with the weakened deformability of RBCs membrane, and the change degree of cell free layer (CFL) thickness decreases as the bending stiffness is relatively higher. Thus, when bending stiffness is higher, the NO concentration in vascular wall is reduced resulting from the thinner CFL.


Assuntos
Endotélio Vascular/metabolismo , Eritrócitos/metabolismo , Hemoglobinas/metabolismo , Microvasos/metabolismo , Modelos Cardiovasculares , Óxido Nítrico/sangue , Animais , Velocidade do Fluxo Sanguíneo , Deformação Eritrocítica , Humanos , Fluxo Sanguíneo Regional , Estresse Mecânico
6.
Zhongguo Zhong Yao Za Zhi ; 41(15): 2855-2860, 2016 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-28914028

RESUMO

An in vitro anti-thrombin bioassay was developed to investigate the chemical constituents which have anti-thrombin effect from the water soluble components of Salvia miltiorrhiza. Using Chromozym TH as a probe combined with ethyl acetate Semi-micro extraction was applied to measure p-nitroaniline by HPLC. According to the results, the inactivationrate of thrombin by sodium danshensu, salvianolic acid A and salvianolic acid B under a given set of conditions were 3.06%, 77.77% and 2.35%, respectively. In the water-soluble components, salvianolic acid A has a direct inhibition of thrombin, while sodium danshensu and salvianolic acid B have no significant effect on thrombin. The method is sensitive and low consumption. It can eliminate the interference absorbed for the sample itself which can be used for screening single or multiple direct antithrombin active ingredient of herbal extract.


Assuntos
Medicamentos de Ervas Chinesas/química , Fibrinolíticos/química , Salvia miltiorrhiza/química , Compostos de Anilina/química , Benzofuranos/química , Ácidos Cafeicos/química , Cromatografia Líquida de Alta Pressão , Lactatos/química , Trombina
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