Tautomeric mixture coordination enables efficient lead-free perovskite LEDs.

Lead halide perovskite light-emitting diodes (PeLEDs) have demonstrated remarkable optoelectronic performance1-3. However, there are potential toxicity issues with lead4,5 and removing lead from the best-performing PeLEDs-without compromising their high external quantum efficiencies-remains a challenge. Here we report a tautomeric-mixture-coordination-induced electron localization strategy to stabilize the lead-free tin perovskite TEA2SnI4 (TEAI is 2-thiopheneethylammonium iodide) by incorporating cyanuric acid. We demonstrate that a crucial function of the coordination is to amplify the electronic effects, even for those Sn atoms that aren't strongly bonded with cyanuric acid owing to the formation of hydrogen-bonded tautomeric dimer and trimer superstructures on the perovskite surface. This electron localization weakens adverse effects from Anderson localization and improves ordering in the crystal structure of TEA2SnI4. These factors result in a two-orders-of-magnitude reduction in the non-radiative recombination capture coefficient and an approximately twofold enhancement in the exciton binding energy. Our lead-free PeLED has an external quantum efficiency of up to 20.29%, representing a performance comparable to that of state-of-the-art lead-containing PeLEDs6-12. We anticipate that these findings will provide insights into the stabilization of Sn(II) perovskites and further the development of lead-free perovskite applications.

Mitigating Surface Defects in Tin-Based Perovskite Films with α-Tocopherol for Enhanced Photovoltaic Performance.

Surface defects in tin-based perovskite films disrupt the periodic arrangement of atoms in crystals, making surface atoms more susceptible to interactions with water and oxygen molecules in the surrounding environment. The diffusion of oxygen ions into the perovskite interior leads to the formation of severe bulk defects, which compromises the performance of tin-based perovskite solar cells (PSCs). As a result, surface defects are recognized as the primary source of degradation and require special attention. In this study, α-Tocopherol (also known as vitamin E) into tin-based perovskite films is introduced. Experimental results show that because of its larger volume, α-Tocopherol does not enter the perovskite lattice. Instead, it forms van der Waals and hydrogen bond interactions with the formamidine ion (FA+) and the [SnI6]4- octahedron at the perovskite terminals. Through α-Tocopherol passivation, both surface and interior oxidation of the perovskite are significantly suppressed as α-Tocopherol firmly embeds itself on the perovskite surface. Density functional theory analysis confirms the inhibition of I─Sn antisite defects (ISn) and Sn interstitial defects (Sni), which possess deep trap states within the bandgap. Ultimately, it is demonstrated that α-Tocopherol enhances the power conversion efficiency (PCE) from 9.19% to 13.14% and prolongs the lifetime of tin-based PSCs to over 50 days.

Efficient Tin Perovskite Solar Cells via Suppressing Autoxidation in Inert Atmosphere.

The unsatisfactory power conversion efficiency (PCE) and long-term stability of tin perovskite solar cells (TPSCs) restrict its further development as alternatives to lead perovskite solar cells (LPSCs). Considerable research has focused on the negative impacts of O2 and H2 O, while discussions about degradation mechanism in an inert atmosphere remains insufficient. Herein, the light-induced autoxidation of tin perovskite in nitrogen atmosphere is revealed for the first time and the elastic lattice distortion is demonstrated as the crucial role of rapid degradation. The continuous injection of photons induces energy transfer from excited A-site cations to vibrating Sn-I framework, leading to the elastic deformation of perovskite lattice. Consequently, the over distorted Sn-I framework releases free iodine and further oxidizes Sn2+ in the form of molecular iodine. Through an appropriately designed light-dark cyclic test, a remarkable PCE of 14.41% is achieved based on (Cs0.025 (MA0.25 FA0.75 )0.975 ) 0.98 EDA0.01 SnI3 solar cells, which is the record of hybrid triple TPSCs so far. The findings unveil autoxidation as the crux of TPSCs' degradation in an inert atmosphere and suggest the possibility of reinforcing the tin perovskite lattice towards highly efficient and stable TPSCs.

Deep-Blue Electroluminescence of Perovskites with Reduced Dimensionality Achieved by Manipulating Adsorption-Energy Differences.

The lagging development of deep-blue perovskite light-emitting diodes (PeLEDs) heavily impedes their practical applications in full-color display due to the absence of spectrally stable emitters and the mismatch of carrier injection capacity. Herein, we report highly efficient deep-blue PeLEDs through a new chemical strategy that addresses the dilemma for simultaneously constant electroluminescence (EL) spectra and high-purify phase in reduced-dimensional perovskites. The success lies in the control of adsorption-energy differences between phenylbutylamine (PBA) and ethylamine (EA) interacting with perovskites, which facilitates narrow n-value distribution. This approach leads to an increased exciton binding energy and enhanced surface potential, hence improving radiative recombination. As a result, an external quantum efficiency of 4.62 % is achieved in PeLEDs with a stable EL peak at 457 nm, demonstrating the best reported result for deep-blue PeLEDs so far.

Growing MASnI3perovskite single-crystal films by inverse temperature crystallization.

Perovskite single-crystal films are promising candidates for high-performance perovskite optoelectronic devices due to their optoelectrical properties. However, there are few reports of single-crystal films of tin based perovskites. Here, for the first time, we realize the controllable growth and preparation of lead-free tin perovskite MASnI3single crystals via inverse temperature crystallization (ITC) strategy with γ-butyrolactone (GBL) as solvent. The solubility characteristics of MASnI3in GBL are clarified by quantitative analytical method. Highly repeatability experiments are further demonstrated using this unique solubility and ITC properties. Sequentially, using space limiting method, tin perovskite MASnI3single-crystal thin films are fabricated with micron-scale thickness, which is highly desired for efficient tin perovskite solar cells. Our MASnI3single-crystal thin films show typical single-crystalline features including strongly optical absorbance with sharp absorption edges, pure-phase x-ray diffraction patterns, and absence of Sn(IV) x-ray photoelectron spectroscopy. We believe that our findings will further broaden the application prospects of tin perovskite MASnI3single crystals and cause a new upsurge in exploring the field of lead-free perovskite single-crystal growth.

Hepatoprotection in a rat model of acute liver damage through inhibition of CY2E1 activity by total alkaloids extracted from Rubus alceifolius Poir.

We aimed to examine the effect of an alkaloid extract of the roots of Rubus alceifolius Poir on liver damage and cytochrome enzymes, and underlying mechanism. Hepatotoxicity was induced in rats by treatment with carbon tetrachloride (CCl(4)). Rats were then treated with the hepatoprotective drug bifendate, or with low, medium, and high doses of an alkaloid extract from the roots of R alceifolius Poir. Both bifendate and alkaloid treatment decreased the increase in liver enzymes and cell damage caused by CCl(4). Carbon tetrachloride treatment alone caused a decrease in total cytochrome P450 content, an increase in CYP2E1 and CYP3A1 messenger RNA (mRNA) levels, and an increase in CYP2E1 and a decrease in CYP3A1 enzymatic activity. Alkaloid treatment brought these concentrations and activities back toward normal. In summary, these results suggest that alkaloids from R alceifolius Poir may act to protect the liver through decreasing CYP2E1 enzymatic activity through decreasing its mRNA.

The Phytochemical Rhein Mediates M6A-Independent Suppression of Adipocyte Differentiation.

Adipogenesis is mediated by the complex gene expression networks involving the posttranscriptional modifications. The natural compound rhein has been linked to the regulation of adipogenesis, but the underlying regulatory mechanisms remain elusive. Herein, we systematically analyzed the effects of rhein on adipogenesis at both the transcriptional and posttranscriptional levels. Rhein remarkably suppresses adipogenesis in the stage-specific and dose-dependent manners. Rhein has been identified to inhibit fat mass and obesity-associated (FTO) demethylase activity. Surprisingly, side-by-side comparison analysis revealed that the rhein treatment and Fto knockdown triggered the differential gene regulatory patterns, resulting in impaired adipocyte formation. Specifically, rhein treatment mildly altered the transcriptome with hundreds of genes dysregulated. N 6-methyladenosine (m6A) methylome profile showed that, although the supply of rhein induced increased m6A levels on a small subset of messenger RNAs (mRNAs), few of them showed dramatic transcriptional response to this compound. Moreover, the specific rhein-responsive mRNAs, which are linked to mitotic pathway, are barely methylated or contain m6A peaks without dramatic response to rhein, suggesting separate regulation of global m6A pattern and adipogenesis mediated by rhein. Further identification of m6A-independent pathways revealed a positive regulator, receptor expressing-enhancing protein 3 (REEP3), in guidance of adipogenesis. Hence, this study provides the mechanistic view of the cellular actions of rhein in the modulation of adipogenesis and identifies a potential novel target for obesity therapeutic research.

[Ultrastructure and TUNEL staining on inhibition of Rubus alceaefolius total alkaloids for apoptosis of liver in rat models of acute hepatitis].

OBJECTIVE: To investigate the anti-apoptosis effects of Rubus alceaefolius total alkaloids in rats with hepatic injury. METHOD: The hepatic injury model of rat was induced by intraperitoneal injection with CCl4. Sixty SD rats were randomly divided into the normal group, the model group, the R. alceaefolius total alkaloids intervened group, and the bifendate intervened group. The expressions of the levels of liver cell apoptosis were determined by TUNEL. Ultrastructures of the liver cells were observed with transmission electron microscope. RESULT: Compared with the model group, the degree of hepatic injury and the positive expressions of apoptosis in liver tissues in the R. alceaefolius total alkaloids intervened groups and the bifendate intervened group were significantly lower. CONCLUSION: R. alceaefolius total alkaloids could reduce the pathological changes and degree of hepatic injury in rats, which may be partially through inhibiting the expressions of apoptosis in liver tissue.

Inhibition of the signal transducer and activator of transcription 3 signaling pathway by Qianliening capsules suppresses the growth and induces the apoptosis of human prostate cells.

The signal transducer and activator of transcription 3 (STAT3) pathway is one of the main growth factor­mediated signal transduction pathways and is closely associated with the occurrence and development of benign prostatic hyperplasia (BPH). Qianliening capsules (QC) have significant therapeutic effects on BPH; however, the precise mechanism underlying its anti­BPH activity remains to be elucidated. To further elucidate the molecular mechanism of the therapeutic effect of QC on BPH, the present study used epidermal growth factor (EGF), which has a role in the pathogenesis of BPH, to stimulate the growth of human prostate WPMY­1 cells and activate the STAT3 pathway in the WPMY­1 cells. The cell viability was determined using an MTT assay and the cell morphology was observed by phase­contrast microscopy. Fluorescence activated cell sorting analysis with Annexin­V/propidium iodide (PI) staining and PI staining were performed to examine cell apoptosis and the cell cycle. The activation of caspase­9 and ­3 were evaluated by colorimetric assay. STAT3 phosphorylation and transcriptional activity were detected by western blot analysis and the luciferase gene reporter, respectively. The mRNA and protein expression levels of B­cell lymhoma 2 (Bcl­2), Bcl­2­associated X protein (Bax), cyclin D1, cyclin­dependent kinase 4 (CDK4) and p21 were measured by reverse transcription quantitative polymerase chain reaction and western blot analysis, respectively. In the present study, QC was found to significantly and dose­dependently inhibit the EGF­stimulated growth of WPMY­1 cells, as evidenced by QC­induced cell -morphological changes and a reduction in cell viability. In addition, QC treatment markedly induced the activation of caspase­9 and ­3. QC treatment also inhibited the EGF­mediated increase of STAT3 phosphorylation levels and transcriptional activity in WPMY­19 cells, accompanied by downregulation of the expression of Bcl­2, cyclin D1 and CDK4 and upregulation of the expression of Bax and p21. These results suggested that QC effectively inhibited the proliferation and promoted the apoptosis of human prostate cells via modulation of the STAT3 signaling pathway and its target genes, which is likely to be one of the mechanisms underlying its activity in BPH treatment.

Anti-proliferative effects of qianliening capsules on prostatic hyperplasia in vitro and in vivo.

Previous studies by our group showed that Qianliening capsules (QC), a clinically proven effective traditional Chinese formulation that has long been used in the treatment of benign prostatic hyperplasia (BPH), is capable of inhibiting BPH in vivo and in vitro via the promotion of apoptosis, suppression of the EGFR/STAT3 signaling pathway and regulating the expression of sex hormones as well as their receptors. However, the mechanism of its anti-BPH activity has remained to be fully elucidated. The present study aimed to investigate the mechanism underlying the anti-proliferative effect of QC in vivo and in vitro. Castrated male Sprage-Dawley (SD) rats where subcutaneously injected with testosterone propionate and the WPMY-1 cell line was stimulated with basic fibroblast growth factor in order to generate BPH in vivo and in vitro separately, both of which were then subjected to QC treatment. Finasteride was used as a positive control drug for the in vivo study. In the present study, it was found that treatment with QC or finasteride significantly reduced the prostatic index (PI=prostate wet weight/body weight x 100) in a rat model of BPH (P<0.05). In addition, reverse transcription quantitative polymerase chain reaction (RT-PCR) and western blot analyses showed that QC or finasteride treatment significantly inhibited model construction-induced upregulation of expression of proliferating cell nuclear antigen, cyclin D1 and cyclin-dependent kinase 4 in prostatic tissues of rats with BPH (P<0.05). The in vitro study further proved that QC exhibited anti-proliferative properties via G1/S cell cycle arrest in the WPMY-1 cell line, as evidenced by colony formation, flow cytometric cell cycle, immunoblot and RT-PCR analyses. In conclusion, the present study demonstrated that inhibition of cell proliferation via G1/S cell cycle arrest may be one of the underlying mechanisms of the effect of QC on BPH.

Qianliening capsules influence the apoptosis of benign prostatic hyperplasia epithelial-1 cells by regulating the extracellular matrix.

The present study investigated whether Qianliening capsules (QC) affected the apoptosis of benign prostatic hyperplastia epithelial (BPH­1) cells by regulating the extracellular matrix (ECM). The levels of fibronectin (FN) and collagen IV were determined in the culture medium of BPH­1 cells maintained in normal medium and of BPH­1 cells maintained in an environment rich in FN and collagen IV using an enzyme­linked immunosorbent assay. Reverse transcription quantitative polymerase chain reaction and western blot analysis were performed to determine the mRNA and protein expression levels of FN, collagen IV, B­cell lymphoma 2 (Bcl­2), Bcl­2­associated X protein (Bax) and cyclin D1, respectively. The cell morphology and viability were determined using light microscopy and an MTT assay and cell apoptosis was detected by annexin V staining. The results demonstrated that FN and collagen IV affected the apoptotic response of the BPH­1 cells, QC treatment significantly reduced the levels of FN and collagen IV secreted by the cells into the culture medium (P<0.01), inhibited the mRNA and protein expression levels of FN, collagen IV, Bcl­2 and cyclin D1 and promoted the mRNA and protein expression of Bax. Therefore, one of the mechanisms underlying the anti­BPH action of QC involves promoting apoptosis by regulating the expression of the extracellular matrix.

Qianliening capsule inhibits benign prostatic hyperplasia angiogenesis via the HIF-1α signaling pathway.

Angiogenesis plays an important role in the progression and development of benign prostatic hyperplasia (BPH), and has become a promising target for BPH treatment. The hypoxia-inducible factor-1α (HIF-1α) signaling pathway promotes the process of angiogenesis, contributing to the growth and progression of a number of hyperplasia diseases, including BPH. Qianliening capsule (QC) is a traditional Chinese formula that has been used clinically in China to treat BPH for a number of years. Recently, QC was demonstrated to inhibit prostatic cell growth and induce apoptosis in vivo and in vitro via regulating the epidermal growth factor/signal transducer and activator of transcription 3 signaling pathway and mitochondrion-dependent apoptosis pathway. However, the mechanisms underlying the anti-BPH effect remain largely unknown. To further elucidate the mechanism of QC activity in BPH treatment, a rat BPH model established by injecting testosterone following castration was established and the effect of QC on prostatic tissue angiogenesis was evaluated, as well as the underlying molecular mechanisms. QC was shown to reduce the prostatic index in BPH rats, but without affecting the body weight, demonstrating that QC is effective in the treatment of BPH and without apparent toxicity. In addition, QC treatment significantly reduced the intraprostatic microvessel density, indicating antiangiogenesis activity in vivo. In addition, treatment with QC inhibited the expression of HIF-1α in BPH rats, as well as the expression of vascular endothelial growth factor and basic fibroblast growth factor. Therefore, for the first time, the present study hypothesized that QC inhibits angiogenesis in prostatic tissue of BPH rats via the inhibition of the HIF-1α signaling pathway, which may be one of the mechanisms in which QC treats BPH.

Treatment of Nonalcoholic Fatty Liver Disease with Total Alkaloids in Rubus aleaefolius Poir through Regulation of Fat Metabolism.

Total alkaloids in Rubus aleaefolius Poir (TARAP) is a folk medicinal herb that has been used clinically in China to treat nonalcoholic fatty liver disease (NAFLD) for many years. However, the mechanism of its anti-NAFLD effect is largely unknown. In this study, we developed a NAFLD rat model by supplying a modified high-fat diet (mHFD) ad libitum for 8 weeks and evaluated the therapeutic effect of TARAP in NAFLD rats as well as the underlying molecular mechanism. We found that TARAP could reduce the serum triglycerides (TG), total cholesterol (TC), and low-density lipoprotein (LDL-C) levels and increase the serum high-density lipoprotein (HDL-C) level in NAFLD rats. In addition, TARAP treatment reduced expression of fatty acid synthetase (FAS), and acetyl-CoA carboxylase (ACC) and upregulated the expression of carnitine palmitoyltransferase (CPT). Our results suggest that regulation of lipid metabolism may be a mechanism by which TARAP treats NAFLD.

Qianliening capsule treats benign prostatic hyperplasia via suppression of the EGF/STAT3 signaling pathway.

Benign prostatic hyperplasia (BPH) is a pathological overgrowth of the human prostate. It may cause increased resistance to urine flow through the urethra and occasionally kidney damage, bladder stones and urinary tract infections, and therefore affect the quality of life. Qianliening capsule (QC) is a traditional Chinese formula that has been used clinically in China to treat BPH for a number of years. However, the mechanism of its anti-BPH effect remains largely unknown. We evaluated the therapeutic effect of QC in a rat model of BPH, established by the injection of testosterone following castration, and investigated the underlying molecular mechanism of action. We observed that QC treatment significantly and dose-dependently decreased the prostatic volume (PV) and prostatic index (PI; P<0.05 or P<0.01), and ameliorated the histological damage of the prostate tissue in the BPH rats. In addition, treatment with QC inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3), as well as the expression of epidermal growth factor (EGF), epidermal growth factor receptor (EGFR), cyclin D1 and Bcl-2. Our results suggest that suppression of the EGF/STAT3 pathway may be one of the mechanisms by which QC treats BPH.

Qianliening capsule () inhibits human prostate cell growth via induction of mitochondrion-dependent cell apoptosis.

OBJECTIVE: To investigate the molecular mechanisms by which Qianliening Capsule (, QC) treats benign prostatic hyperplasia (BPH). METHODS: Human prostate stromal cell line WPMY-1 was treated with 0, 1, 3 and 5 mg/mL of QC for 24, 48 and 72 h, respectively, in the presence of 10 ng/mL basic fibroblast growth factor (bFGF). The viability of WPMY-1 cells was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell morphology was observed by phase-contrast microscopy. 4',6-diamidino-2-phenylindole (DAPI) staining and fluorescence activated cell sorting (FACS) analysis with Annexin-V/propidium iodide (PI) staining were performed to determine cell apoptosis. The loss of mitochondrial membrane potential was examined by FACS analysis with 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyarine iodide (JC-1) staining. Activation of caspase-3 and -9 was evaluated by colorimetric assay. The mRNA and protein expression levels of Bcl-2 and Bax were measured by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting, respectively. RESULTS: Upon bFGF stimulation, the viability of WPMY-1 cells was increased to 122%-118% compared with the control cells (P <0.05). However, treatment with 1-5 mg/mL of QC for 24, 48 and 72 h decreased the viability of bFGF-stimulated cells to 80%-92%, 59%-82%, 36%-62% compared with the untreated cells (P <0.05). In addition, QC treatment reduced WPMY-1 cell density in a dose-dependent manner. Moreover, QC treatment dose-dependently induced the loss of plasma membrane asymmetry, the nuclear condensation and fragmentation, collapse of mitochondrial membrane potential, activation of caspase-9 and caspase-3, and increase of pro-apoptotic Bax/Bcl-2 ratio. CONCLUSION: Promoting mitochondrion-dependent apoptosis of prostate stromal cells might be one of the mechanisms by which QC treats BPH.

Hepatoprotective effects of Rubus aleaefolius Poir. and identification of its active constituents.

The purpose of this study was to study the hepatoprotective effects of the most promising extract of the root from Rubus aleaefolius Poir. and to isolate and identify the active components. Various crude forms of Rubus aleaefolius have been evaluated for their effects on CCl(4)-induced acute liver injury in mice vivo experimental model. Treatment groups contained 5 sub-groups that were ethanol crude extract; the high/low dosage ethyl acetate or n-butanol fraction; extracted with ethyl acetate or n-butanol after the residues and major constituent; intragastrically administrated with 35 mg/kg; 35, 4.6 mg/kg; 35, 5.8 mg/kg; 35 mg/kg and 3.5 mg/kg for 7 days. The serum samples were collected for biological analysis and also carried out histopathological studies. The low-dosage ethyl acetate fraction was the most active when the fractions were compared. It was found to decrease AST, ALT; to prevent formation of hepatic MDA, NO and intensify the activity of SOD. The histopathological changes induced by CCl(4) were also significantly reduced. The separation revealed the presence of six constituents by a bioassay-guided fractionation, beta-Sitosterol (1), 1beta-Hydroxyeuscaphic acid (2), Oleanolic acid (3), Myrianthic acid (4), Euscaphic acid (5), and Tomentic acid (6). Among them, compounds 2, 4, 5 in Rubus aleaefolius root is reported here for the first time. 1beta-Hydroxyeuscaphic acid (major constituent) showed a tremendous activity and the results confirm the traditional uses of Rubus aleaefolius in treating hepatitis.