RESUMO
Circularly polarized light (CPL) is essential for optoelectronic and chiro-spintronic applications. Hybrid perovskites, as star optoelectronic materials, have demonstrated CPL activity, which is, however, mostly limited to chiral perovskites. Here, we develop a simple, general, and efficient strategy to stimulate CPL activity in achiral perovskites, which possess rich species, efficient luminescence, and tunable bandgaps. With the formation of van der Waals heterojunctions between chiral and achiral perovskites, a nonequilibrium spin population and thus CPL activity are realized in achiral perovskites by receiving spin-polarized electrons from chiral perovskites. The polarization degree of room-temperature CPL in achiral perovskites is at least one order of magnitude higher than in chiral ones. The CPL polarization degree and emission wavelengths of achiral perovskites can be flexibly designed by tuning chemical compositions, operating temperature, or excitation wavelengths. We anticipate that unlimited types of achiral perovskites can be endowed with CPL activity, benefiting their applications in integrated CPL sources and detectors.
RESUMO
Objective To observe the therapeutic effect of empagliflozin (EM) on renal injury in rats with type 2 diabetes mellitus (T2DM), and to explore its possible mechanism. Methods Male SD rats were randomly divided into a normal control (NC) group, a T2DM group, and an EM group, with 6 rats in each group. T2DM models were established by an intraperitoneal injection of streptozotocin (STZ) in the T2DM and EM groups. Fasting blood glucose (FBG) levels and body mass of rats in each group were recorded. The EM group received EM solution through intragastric administration, while the other two groups were given an equivalent volume of sodium carboxymethyl cellulose solution through intragastric administration for 12 weeks. After the body mass and FBG levels were recorded, the rats were sacrificed and blood samples from the abdominal aorta and kidney tissues were collected. Serum creatinine (Scr), blood urea nitrogen (BUN), uric acid (UA), triglyceride (TG) and total cholesterol (TC) were detected by automatic biochemical analyzer. Masson, PAS and HE staining were used to assess histological changes in the kidneys, and a transmission electron microscopy was used to observe ultrastructural changes. Immunohistochemical staining was used to detect the expression and distribution of exchange protein 1 directly activated by cAMP(Epac1), TNF-α, IL-1ß, and IL-18 in renal tissue of rats. Results Compared with the NC group, the rats in T2DM group showed a decrease in body mass, a significant increase in the levels of FBG, Scr, BUN, UA, TC, and TG, thickened glomerular basement membrane, foot process fusion of podocytes, disordered cell arrangement and loss of endothelial cell fenestrations. The expression level of Epac1 decreased, while the expression levels of TNF-α, IL-1ß, and IL-18 significantly increased. Compared with the T2DM group, the rats in the EM group showed an increase in body mass, significantly decreased levels of FBG, Scr, BUN, UA, TC, and TG, reduced renal injury, increased expression level of Epac1, and significantly decreased expression levels of TNF-α, IL-1ß, and IL-18. Conclusion EM can improve renal injury in T2DM rats by up-regulating Epac1 expression to inhibit inflammatory response.
Assuntos
Compostos Benzidrílicos , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Glucosídeos , Ratos , Masculino , Animais , Ratos Sprague-Dawley , Interleucina-18/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Fator de Necrose Tumoral alfa/metabolismo , Rim , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/etiologiaRESUMO
Organic-inorganic hybrid perovskites (OIHPs) have proven to be promising active layers for nonvolatile memories because of their rich abundance in earth, mobile ions, and adjustable dimensions. However, there is a lack of investigation on controllable fabrication and storage properties of one-dimensional (1D) OIHPs. Here, the growth of 1D (NH=CINH3)3PbI5 ((IFA)3PbI5) perovskite and related resistive memory properties are reported. The solution-processed 1D (IFA)3PbI5 crystals are of well-defined monoclinic crystal phase and needle-like shape with the length of about 6 mm. They exhibit a wide bandgap of 3 eV and a high decomposition temperature of 206°C. Moreover, the (IFA)3PbI5 films with good uniformity and crystallization were obtained using a dual solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). To study the intrinsic electric properties of this anisotropic material, we constructed the simplest memory cell composed of only Au/(IFA)3PbI5/ITO, contributing to a high-compacted device with a crossbar array device configuration. The resistive random access memory (ReRAM) devices exhibit bipolar current-voltage (I-V) hysteresis characteristics, showing a record-low power consumption of ~0.2 mW among all OIHP-based memristors. Moreover, our devices own the lowest power consumption and "set" voltage (0.2 V) among the simplest perovskite-based memory devices (inorganic ones are also included), which are no need to require double metal electrodes or any additional insulating layer. They also demonstrate repeatable resistance switching behaviour and excellent retention time. We envision that 1D OIHPs can enrich the low-dimensional hybrid perovskite library and bring new functions to low-power information devices in the fields of memory and other electronics applications.