Metformin reduces proteinuria in spontaneously hypertensive rats by activating the HIF-2α-VEGF-A pathway.

Metformin has protective effects on diabetic nephropathy. However, the mechanism underlying the renoprotective action of metformin in spontaneously hypertensive rats (SHR) is not completely understood. We determined the role of metformin in proteinuria and investigated the mechanism. We measured the urinary protein concentration (mg/day) in 48-week-old SHR. Matched control animals were of the same genetic strain, Wistar-Kyoto (WKY). The rats received metformin (100 mg/kg/day) or vehicle for 10 months. Metformin improved renal function and reduced the proteinuria (urine protein: 48.4 ± 3.7 vs. 25.4 ± 1.8 mg, P < 0.01) induced by long-term high blood pressure. Metformin increased the production of vascular endothelial growth factor (VEGF)-A in rat kidneys and cultured rat podocytes. Metformin activated hypoxia-inducible factor-2α (Hif-2α) in response to VEGF but did not affect Hif-1α in rat kidneys and cultured rat podocytes. Metformin reduced the proteinuria induced by long-term high blood pressure in vivo and increased the VEGF-A production in rat kidneys and cultured rat podocytes, probably by activating the Hif-2α-VEGF signaling pathway. These findings provide a new mechanism for the renoprotective effects of metformin.

Effect of correlated colour temperature and illuminance levels on user's visual perception under LED lighting in Taiwan.

This study aimed to utilise the characteristics of light-emitting diode (LED) lighting, including the adjustable correlated colour temperature (CCT) and illuminance levels, to evaluate the effects of various CCT and illuminance level combinations on visual perception and their patterns under different lighting conditions. Five white light balances with different CCTs were created together with four levels of illuminance. Based on the patterns of visual perception, when the CCT increased with the illuminance levels, the participants' visual perception changed from dim, boring, and sleepy to intense, vivid, energetic, and bright. As the CCT decreased, the participants gradually perceived the lighting as warm and relaxing. As illuminance levels increased, dim and unpleasant feelings progressively changed to bright and pleasant ones. The study attempted to identify lighting combinations that can respond to different psychological needs and can be used as a guide in the future design of lighting equipment. Practitioner summary: Appropriate lighting conditions could aid individuals in increasing the quality of life. This study conducted an experiment to evaluate the effects of various correlated colour temperature and illuminance level combinations on visual perception by using LED lighting. The results showed the effect of the different lighting combinations on the visual perception of the participants. Abbreviation: LED: light-emitting diode; CCT: correlated colour temperature; K: Kelvin; lx: Lux; CIE: Commission Internationale de l'Eclairage; ANSI: American National Standards Institute.

Sensitivity Enhancement of Transition Metal Dichalcogenides/Silicon Nanostructure-based Surface Plasmon Resonance Biosensor.

In this work, we designed a sensitivity-enhanced surface plasmon resonance biosensor structure based on silicon nanosheet and two-dimensional transition metal dichalcogenides. This configuration contains six components: SF10 triangular prism, gold thin film, silicon nanosheet, two-dimensional MoS2/MoSe2/WS2/WSe2 (defined as MX2) layers, biomolecular analyte layer and sensing medium. The minimum reflectivity, sensitivity as well as the Full Width at Half Maximum of SPR curve are systematically examined by using Fresnel equations and the transfer matrix method in the visible and near infrared wavelength range (600 nm to 1024 nm). The variation of the minimum reflectivity and the change in resonance angle as the function of the number of MX2 layers are presented respectively. The results show that silicon nanosheet and MX2 layers can be served as effective light absorption medium. Under resonance conditions, the electrons in these additional dielectric layers can be transferred to the surface of gold thin film. All silicon-MX2 enhanced sensing models show much better performance than that of the conventional sensing scheme where pure Au thin film is used, the highest sensitivity can be achieved by employing 600 nm excitation light wavelength with 35 nm gold thin film and 7 nm thickness silicon nanosheet coated with monolayer WS2.

The non-aqueous synthesis of shape controllable Cu(2-x)S plasmonic nanostructures in a continuous-flow millifluidic chip for the generation of photo-induced heating.

In this paper, a new method for synthesizing non-aqueous copper sulfide nanocrystals with different shapes and sizes using a homemade continuous-flow millifluidic chip is presented. Conventionally, the shape control of nanocrystals was accomplished using a surfactant-controlled approach, where directional growth is facilitated by selective passivation of a particular facet of the nanocrystals using surfactants. We demonstrate a "surfactant-free" approach where different sizes and shapes (i.e. spherical, triangular prism and rod) of plasmonic copper sulfide (Cu(2-x)S) nanocrystals can be fabricated by adjusting the flow rate and precursor concentrations. As continuous-flow synthesis enables uniform heating and easy variation of precursors' stoichiometries, it serves as an excellent incubation platform for nanoparticles due to its simplicity and high reproducibility. Transmission electron microscopy (TEM), fast Fourier transform (FFT) and X-ray diffraction (XRD) techniques were used to characterize the as-synthesized nanocrystals and revealed structures ranging from copper-deficient covellite (CuS), spionkopite (Cu1.39S), roxbyite (Cu1.75S), to copper-rich djurleite (Cu1.94S). The localized surface plasmon resonance (LSPR) peak of the nanocrystals can be tuned from 1115 to 1644 nm by simply varying the copper to sulfur molar ratio and flow rate. Furthermore, photothermal effects of Cu(2-x)S nanocrystals were also demonstrated to annihilate the RAW264.7 cells upon near infra-red laser irradiation.