Optimizing the Buried Interface in Flexible Perovskite Solar Cells to Achieve Over 24% Efficiency and Long-Term Stability.

The buried interface of the perovskite layer has a profound influence on its film morphology, defect formation, and aging resistance from the outset, therefore, significantly affects the film quality and device performance of derived perovskite solar cells. Especially for FAPbI3 , although it has excellent optoelectronic properties, the spontaneous transition from the black perovskite phase to nonperovskite phase tends to start from the buried interface at the early stage of film formation then further propagate to degrade the whole perovskite. In this work, by introducing ─NH3 + rich proline hydrochloride (PF) with a conjugated rigid structure as a versatile medium for buried interface, it not only provides a solid α-phase FAPbI3 template, but also prevents the phase transition induced degradation. PF also acts as an effective interfacial stress reliever to enhance both efficiency and stability of flexible solar cells. Consequently, a champion efficiency of 24.61% (certified 23.51%) can be achieved, which is the highest efficiency among all reported values for flexible perovskite solar cells. Besides, devices demonstrate excellent shelf-life/light soaking stability (advanced level of ISOS stability protocols) and mechanical stability.

Ligand Engineering in Tin-Based Perovskite Solar Cells.

Perovskite solar cells (PSCs) have attracted aggressive attention in the photovoltaic field in light of the rapid increasing power conversion efficiency. However, their large-scale application and commercialization are limited by the toxicity issue of lead (Pb). Among all the lead-free perovskites, tin (Sn)-based perovskites have shown potential due to their low toxicity, ideal bandgap structure, high carrier mobility, and long hot carrier lifetime. Great progress of Sn-based PSCs has been realized in recent years, and the certified efficiency has now reached over 14%. Nevertheless, this record still falls far behind the theoretical calculations. This is likely due to the uncontrolled nucleation states and pronounced Sn (IV) vacancies. With insights into the methodologies resolving both issues, ligand engineering-assisted perovskite film fabrication dictates the state-of-the-art Sn-based PSCs. Herein, we summarize the role of ligand engineering during each state of film fabrication, ranging from the starting precursors to the ending fabricated bulks. The incorporation of ligands to suppress Sn2+ oxidation, passivate bulk defects, optimize crystal orientation, and improve stability is discussed, respectively. Finally, the remained challenges and perspectives toward advancing the performance of Sn-based PSCs are presented. We expect this review can draw a clear roadmap to facilitate Sn-based PSCs via ligand engineering.

Ewing Sarcoma and Primitive Neuroectodermal Tumor of the Thoracic Esophagus: Case Report and Comprehensive Literature Review.

Ewing sarcoma and primitive neuroectodermal tumors (ES/PNETs) are rare tumors that belong to a family of round-cell neuroectodermally derived tumors, and their optimal treatment remains a great challenge. This study presented a case of ES/PNET, arising in the esophagus of a 21-year-old female patient presented with progressive dysphagia. Computed tomography and endoscopic ultrasonography showed a well-defined, submucosal solid mass in the superthoracic esophagus. The accurate diagnosis after surgery was obtained through immunohistochemistry and genetic studies, namely the CD99 immunopositivity as well as the EWSR1/FLI1 gene rearrangement associated with t(11;22)(q24;q12) in tumor cells. The patient underwent localized tumor resection followed by chemotherapy and chest radiotherapy. The patient is doing well with no evidence of tumor recurrence or metastasis 18 months after surgery. Although the esophagus is a rare site for ES/pPNET, we can speculate that the treatment protocol of ES/pPNET should include multi-agent chemotherapy, surgery, and local radiotherapy in order to improve the prognosis based on our report.

Formamidine Acetate Induces Regulation of Crystallization and Stabilization in Sn-Based Perovskite Solar Cells.

Sn-based perovskite solar cells (PSCs) have received extensive attention for photovoltaic applications. Nevertheless, the low crystallization quality of the film due to rapid crystallization results in high trap density of states, which is one of the main reasons for poor performance of Sn-based PSC devices. In this work, we developed a strategy for the formation of FASnI3 perovskites by introducing the addition of formamidine acetate (FAAc). Benefiting from the iodide-coordinated cation (FA+) and crystallization-regulated anion (AC-), FAAc could achieve the high-quality films with suppressed defects. The champion power conversion efficiency (PCE) of FAAc-modified PSC devices reached 9.96%, reserving 82% of their initial PCE of the light aging test over 1500 h. We hope that our finding could provide implications on the high-performance and stable Sn-based PSCs.

Acute Respiratory Distress Syndrome Prediction Score: Derivation and Validation.

BACKGROUND: Despite advances in treatment strategies, acute respiratory distress syndrome (ARDS) after cardiac surgery remains associated with high morbidity and mortality. A method of screening patients for risk of ARDS after cardiac surgery is needed. OBJECTIVES: To develop and validate an ARDS prediction score designed to identify patients at high risk of ARDS after cardiac or aortic surgery. METHODS: An ARDS prediction score was derived from a retrospective derivation cohort and validated in a prospective cohort. Discrimination and calibration of the score were assessed with area under the receiver operating characteristic curve and the Hosmer-Lemeshow goodness-of-fit test, respectively. A sensitivity analysis was conducted to assess model performance at different cutoff points. RESULTS: The retrospective derivation cohort consisted of 201 patients with and 602 patients without ARDS who had undergone cardiac or aortic surgery. Nine routinely available clinical variables were included in the ARDS prediction score. In the derivation cohort, the score distinguished patients with versus without ARDS with area under the curve of 0.84 (95% CI, 0.81-0.88; Hosmer-Lemeshow P = .55). In the validation cohort, 46 of 1834 patients (2.5%) had ARDS develop within 7 days after cardiac or aortic surgery. Area under the curve was 0.78 (95% CI, 0.71-0.85), and the score was well calibrated (Hosmer-Lemeshow P = .53). CONCLUSIONS: The ARDS prediction score can be used to identify high-risk patients from the first day after cardiac or aortic surgery. Patients with a score of 3 or greater should be closely monitored. The score requires external validation before clinical use.

In vitro screening for compounds from Hypericum longistylum with anti-pulmonary fibrosis activity.

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with a poor prognosis and limited therapies, and transforming growth factor-ß1 (TGF-ß1) plays a central role in the pathogenesis of IPF. Here, we aimed to investigate the chemical constituents and biological activities of Hypericum longistylum and detect whether the isolated compounds inhibit the TGF-ß1/Smad3 signaling pathway to identify candidate compounds for the treatment of pulmonary fibrosis. Fifteen compounds (1-15) were isolated from H. longistylum and their structures were elucidated on the basis of spectroscopic analyses. An in vitro MTT assay was used to test the effect of these fifteen compounds on fibroblast cytotoxicity and vitality. Furthermore, their bioactivities were screened using a TGF-ß1/Smad3 pathway luciferase reporter in vitro. MTT screening found that compounds 1-15 had no deleterious effects on normal mouse lung fibroblasts and no significant inhibition of vitality. Luciferase assay showed that compounds 14 and 15 could significantly inhibit the TGF-ß1/Smad3 pathway with the inhibition rates of 67.92% and 93.10%, respectively. Both compounds can be used as lead compounds for structural modification and optimization to obtain more drug candidates for the treatment of pulmonary fibrosis.

Different Effects of Melatonin on X-Rays-Irradiated Cancer Cells in a Dose-Dependent Manner.

The purpose of this study is to investigate the effects of melatonin on the radiosensitivity of HeLa cells. Concentration from 10 to 1000 µM of melatonin was used on HeLa cells before X-rays irradiation (IR). The cellular inactivation effect was analyzed by clonogenic assay, and cell growth was measured by MTT assay at various concentrations. Ten micrometer melatonin promoted the cell-killing effects of IR, while 1000-µM melatonin prevented IR-induced cellular inactivation. Further analysis revealed that 1000-µM melatonin protected the cells from IR-induced reactive oxygen species damage, as the oxidative stress measured by fluorescent microscopy and fluorescence-activated cell sorting using 2,7-dichlorofluorescein diacetate staining. This is further confirmed by melatonin receptor agonist, which has no antioxidant capacity. A 10-µM melatonin, on the contrary, enhanced the cell-killing effects of IR by activating c-Jun NH2-terminal kinase (JNK) signaling. c-Jun NH2-terminal kinase signaling activation was indicated by Western blot of phosphorylated JNK. We used JNK inhibitor to further confirm the involvement of JNK signaling in the cell-killing enhancement of 10-µM melatonin administration. Our results suggest the importance of dose-dependent effects in melatonin application for radiotherapy.

Cs2NaVCl6: A Pb-Free Halide Double Perovskite with Strong Visible and Near-Infrared Light Absorption.

Developing environmentally friendly, stable, and narrow and direct band gap halide perovskite materials has attracted substantial interest because of their wide range of potential applications. Here, an all-inorganic Pb-free halide double perovskite, Cs2NaVCl6, was prepared by the solid-state reaction method and hydrothermal method. Cs2NaVCl6 crystallizes in the cubic Fm3̅m space group with the unit parameter a = 10.3497(14) Å. The combined density functional theory and experimental study demonstrates that the compound is a direct band gap semiconductor with a band gap of ∼2.64 eV. More importantly, it exhibits strong visible and near-infrared light absorptions and markedly ambient and thermal stability.

Design and synthesis of novel celastrol derivative and its antitumor activity in hepatoma cells and antiangiogenic activity in zebrafish.

Two series of celastrol derivatives were designed and synthesized by modifying carboxylic acid at the 28th position with amino acid, and their intermediates with isobutyrate at the third position. All compounds were evaluated for their antiproliferation activity by four human cancer cell lines (SCG7901, HGC27, HepG2, and Bel7402) and one normal cell LO2. The most promising compound, compound 8, showed superior bioactivity and lower toxicity than others including celastrol. Further underlying tests illustrated that compound 8 induced apoptosis and cell arrest at G2/M and inhibited proliferation and mobility of human hepatoma cells by suppressing the signal transducer and activator of transcription-3 signaling pathway. Besides these, a highly accurate and reproducible high performance liquid chromatography protocol was established to determine celastrol and compound 8 absorption in zebrafish, and results demonstrated that their concentration increased rapidly within 4 hr in a time-dependent manner and the concentration of compound 8 was higher than that of celastrol. In addition, without detection at 12 hr, compound 8 was rapidly metabolized in vivo. These findings are very helpful for the structural modification of celastrol and other bioactive compounds to improve their bioactivity, toxicity, and absorption.

Extractive from Hypericum ascyron L promotes serotonergic neuronal differentiation in vitro.

BACKGROUND: Plant natural products have many different biological activities but the precise mechanisms underlying these activities remain largely unknown. Hypericum longistylum has long been recorded in Chinese medicine as a cure for depression and related disorders, but how it repairs neural lineages has not been addressed. METHODS: We extracted compounds from Hypericum longistylum and determined their effect on neural differentiation of embryonic stem cells (ESCs) in vitro by using the Pax6-GFP reporter system. The amount of serotonin released during differentiation was measured by HPLC. The tail suspension test and forced swimming test was performed for determining the effect of compounds on depression-like behaviors in mice. RESULTS: We found that one of the phloroglucinol derivatives not only facilitated differentiation of neural progenitor cells, but also increased the efficiency of differentiation into serotonergic neurons. This compound also improved the behaviors of mice placed in a stressful environment and reduced signs of depression. CONCLUSIONS: This is the first use of Chinese herb derived-natural products to promote neurogenesis of ESCs, including the generation of serotonergic neurons, and the first attempt to identify the active compound in Hypericum longistylum responsible for its beneficial effects on depressive diseases.

Streptococcus suis DivIVA Protein Is a Substrate of Ser/Thr Kinase STK and Involved in Cell Division Regulation.

Streptococcus suis serotype 2 is an important swine pathogen and an emerging zoonotic agent that causes severe infections. Recent studies have reported a eukaryotic-like Ser/Thr protein kinase (STK) gene and characterized its role in the growth and virulence of different S. suis 2 strains. In the present study, phosphoproteomic analysis was adopted to identify substrates of the STK protein. Seven proteins that were annotated to participate in different cell processes were identified as potential substrates, which suggests the pleiotropic effects of stk on S. suis 2 by targeting multiple pathways. Among them, a protein characterized as cell division initiation protein (DivIVA) was further investigated. In vitro analysis demonstrated that the recombinant STK protein directly phosphorylates threonine at amino acid position 199 (Thr-199) of DivIVA. This effect could be completely abolished by the T199A mutation. To determine the specific role of DivIVA in growth and division, a divIVA mutant was constructed. The ΔdivIVA strain exhibited impaired growth and division, including lower viability, enlarged cell mass, asymmetrical division caused by aberrant septum, and extremely weak pathogenicity in a mouse infection model. Collectively, our results reveal that STK regulates the cell growth and virulence of S. suis 2 by targeting substrates that are involved in different biological pathways. The inactivation of DivIVA leads to severe defects in cell division and strongly attenuates pathogenicity, thereby indicating its potential as a molecular drug target against S. suis.

Fibroblast growth factor 21 attenuates calcification of vascular smooth muscle cells in vitro.

OBJECTIVES: Vascular calcification is a dysfunction of the vasculature. Recent findings indicate that fibroblast growth factor21 (FGF21), a protector of the cardiovascular system, is related to the mineral deposition of bone and enhances the osteogenic activity of bone morphogenic protein (BMP)-2. In this study, we explored whether FGF21 suppresses vascular calcification. METHODS: A calcifying model was established by culturing primary rat vascular aortic smooth muscle cells (VSMCs) in a beta-glycerophosphate (BGP)-containing calcifying medium for 14 days. In addition, recombinant human FGF21 was applied to protect against VSMC calcification. RESULTS: In the presence of BGP, the expression levels of osteoblastic genes, including alkaline phosphatase (ALP), BMP-2 and runt-related transcription factor (RUNX)-2, were significantly upregulated on day 3, an effect that was maintained through day 14 (P < 0.001). A concomitant increase in ALP protein expression was observed through day 9 (P < 0.05). The incubation of VSMCs with calcifying medium for 14 days increased ALP activity (P < 0.05) and led to the formation of visible calcium nodules over the course of the protocol. ß-klotho expression was unaltered in BGP-induced VSMCs for the 14-day culture period. The culturing of VSMCs with calcifying medium led to opposing trends in the expression of FGFRs, namely, an increase in FGFR1 and FGFR4 mRNA levels (P < 0.001) and a decrease in FGFR2 and FGFR3 mRNA levels (P < 0.01). Reduced mineral deposition, in combination with decreased ALP activity (P < 0.001) and ALP protein expression (P < 0.001), was noted in VSMCs treated with varying doses of FGF21 and BGP in a dose-dependent manner. In addition, FGF21 downregulated osteoblastic-promoting gene expression, including ALP (P < 0.001), BMP-2 (P < 0.001) and RUNX-2 (P < 0.001). Furthermore, FGF21 enhanced ß-klotho expression (P < 0.05) and increased FGFR1 and FGFR3 mRNA levels (P < 0.001). FGFR-1 inhibitor SU5402 blocked partial inhibition of FGF21 on the expression of BMP-2 (P < 0.001) and RUNX-2 (P < 0.05). Furthermore, FGF21 suppressed the phosphorylation of P38, while P38 inhibitor, SB203580, attenuated the downregulation of RUNX-2 (P < 0.05). CONCLUSIONS: These data demonstrate FGF21 attenuates VSMC calcification in vitro via an FGF21/FGFR1/3/ß-klotho/P38MAPK/RUNX-2 signalling pathway.

Polycyclic phloroglucinols as PTP1B inhibitors from Hypericum longistylum: Structures, PTP1B inhibitory activities, and interactions with PTP1B.

Protein tyrosine phosphatase 1B (PTP1B) has been regarded asa target for the research and development of new drugs to treat type II diabetes and PTP1B inhibitors are potential lead compounds for this type of new drugs. A phytochemical investigation to obtain new PTP1B inhibitors resulted in the isolation of four new phloroglucinols, longistyliones A-D (1-4) from the aerial parts of Hypericum longistylum. The structures of 1-4 were elucidated on the basis of extensive 1D and 2D NMR spectroscopic data analysis, and the absolute configurations of these compounds were established by comparing their experimental electronic circular dichroism (ECD) spectra with those calculated by the time-dependent density functional theory method. Compounds 1-4 possess a rare polycyclic phloroglucinol skeleton. The following biological evaluation revealed that all of the compounds showed PTP1B inhibitory effects. The further molecular docking studies indicated the strong interactions between these bioactive compounds with the PTP1B protein, which revealed the possible mechanism of PTP1B inhibition of bioactive compounds. All of the results implied that these compounds are potentially useful for the treatment of type II diabetes.

Fibroblast growth factor 21 plays an inhibitory role in vascular calcification in vitro through OPG/RANKL system.

Vascular calcification is prevalent and associated with adverse outcome without available therapy. The benefits of fibroblast growth factor (FGF)-21 on metabolism and atherosclerosis make it a promising therapeutic agent for vascular calcification. We investigated the effects of FGF21 on vascular smooth muscle cell (VSMC) calcification by culturing rat VSMCs in a calcifying medium for 9days. FGF21 markedly attenuated mineral deposition and apoptosis at the indicated time points. In the presence of FGF21, the expression levels of osteoblastic protein including bone morphogenic protein-2, alkaline phosphatase(ALP), runt-related transcription factor(RUNX)-2 and nuclear factor-kappa B ligand (RANKL) were down-regulated, whereas the expression of osteoprotegerin (OPG) increased. Knockdown of OPG significantly impaired inhibition of FGF21 on apoptosis and the expression of pro-apoptotic genes including caspase-3 and Bax and osteoblastic -promoting markers including ALP, RUNX-2 and RANKL. Furthermore, FGF21 facilitated the phosphoryl of AKT but suppressed P38, while OPG knockdown attenuated the effects. LY29400 (inhibitor of PI3K) abrogated the activation of PI3K/AKT and SB203580 (inhibitor of P38) abolished the inhibition of FGF21 on P38, while alteration was observed in the expression of RUNX-2. FGF21 inhibited VSMCs calcification via OPG/RANKL system, and through P38 andPI3K/AKT pathways.

A novel synthetic Asiatic acid derivative induces apoptosis and inhibits proliferation and mobility of gastric cancer cells by suppressing STAT3 signaling pathway.

Activation of the transcription factor, signal transducers and activators of transcription 3 (STAT3), has been linked to the proliferation and migration of a variety of human cancer cells. These actions occur via the upregulation or downregulation of cell survival and tumor suppressor genes, respectively. Importantly, agents that can suppress STAT3 activation have the potential for use in the prevention and treatment of various cancers. In this study, an Asiatic acid (AA) derivative, N-(2α,3ß,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), is reported to dose dependently suppress constitutive STAT3 activation in gastric cancer cells. This inhibition was mediated by blockade of Janus-activated kinase 2. Additionally, AA-PMe regulated the expression of STAT3-modulated gene products, including cyclin D1, Bax, Bcl-2, c-Myc, and matrix metalloproteinase (MMP)-2 and MMP-9. Finally, transfection with both a STAT3 mimic and an inhibitor reversed the AA-PMe-driven modulation of STAT3 downstream gene products. Overall, these results suggest that AA-PMe is a novel blocker of STAT3 activation and has the potential for the prevention and treatment of gastric cancer.

Bioactive Terpenoids from Salvia plebeia: Structures, NO Inhibitory Activities, and Interactions with iNOS.

A phytochemical investigation to obtain new NO inhibitors resulted in the identification of six new (1-6) and four known (7-10) terpenoids from Salvia plebeia. Compounds 1 and 2 are new diterpenoids, 3-5 are new meroditerpenoids, 6-9 are sesquiterpenoids, and 10 is a known meroditerpenoid. The structures of these isolates were determined by routine NMR experiments and X-ray diffraction, as well as the electronic circular dichroism spectra. Compounds 1-4 are diterpenoids carrying an oxygen bridge, and 6 is a rare copane-type sesquiterpenoid with a bridged tricyclic framework. The isolates inhibited NO generation induced by lipopolysaccharide in BV-2 cells. The possible mechanism of NO inhibition of some bioactive compounds was also investigated using molecular docking, which revealed interactions of bioactive compounds with the iNOS protein.

Characterization of diterpenoids from Caesalpinia decapetala and their anti-TMV activities.

Caesalpinia decapetala is a versatile medicinal plant belonging to the Fabaceae plant family. In our survey on plant secondary metabolites to obtain bioactive substances for the development of new agricultural anti-TMV agents, the chemical constituents of C. decapetala were investigated. This investigation led to the isolation of three new and ten known diterpenoids. Their structures including absolute configurations were elucidated based on the extensive NMR spectroscopic data analyses and the time-dependent density functional theory calculations. The following biological screenings revealed that most of these diterpenoids possessed anti-TMV activities.

Di- and Triterpenoids from the Leaves of Casearia balansae and Neurite Outgrowth Promoting Effects of PC12 Cells.

A bioassay-guided phytochemical investigation of the leaves of Casearia balansae led to the isolation of six new cucurbitane-type triterpenoid derivatives (balanterpenes A-F, 1-6) and four new clerdoane-type diterpenoids (balanterpenes G-J, 7-10). The structures of 1-10 were established on the basis of extensive analysis of NMR spectroscopic data, X-ray crystallography, and experimental and calculated electronic circular dichroism spectra. Compound 1 features a ring-expanded triterpenoid skeleton with the C-19 methyl involved in the ring formation, compound 6 possesses a rare hexanortriterpenoid scaffold, and compounds 7-10 may be four new diterpenoid artifacts presumably formed during the extraction and purification processes. Compounds 3 and 7-10 showed promoting effects on neurite outgrowth of PC12 cells with EC50 values in the range 2.9-10.0 µM.

Characterization and Biological Evaluation of Diterpenoids from Casearia graveolens.

Biologically active substances that promote the neurite outgrowth of nerve cells against neuron degeneration may be useful for the treatment of Alzheimer's disease. In a continuing search for bioactive compounds from plants, an ethyl acetate-soluble extract of the twigs of Casearia graveolens showed moderate stimulatory activity of neurite outgrowth from PC12 cells. Further investigation to obtain bioactive compounds led to the isolation of 10 new clerodane diterpenoids, graveopenes A-J (1-10). Their structures including absolute configurations were elucidated based on analysis of their NMR spectroscopic data and experimental and calculated ECD spectra. Compounds 3-6 and 8 were shown to stimulate NGF-mediated neurite outgrowth from PC12 cells.

Characterization of Diterpenes from Euphorbia prolifera and Their Antifungal Activities against Phytopathogenic Fungi.

Euphorbia prolifera is a poisonous plant belonging to the Euphorbiaceae family. In this survey on plant secondary metabolites to obtain bioactive substances for the development of new antifungal agents for agriculture, the chemical constituents of the plant E. prolifera were investigated. This procedure led to the isolation of six new and two known diterpenes. Their structures, including absolute configurations, were elucidated on the basis of extensive NMR spectroscopic data analyses and time-dependent density functional theory ECD calculations. Biological screenings revealed that these diterpenes possessed antifungal activities against three phytopathogenic fungi. The results of the phytochemical investigation further revealed the chemical components of the poisonous plant E. prolifera, and biological screenings implied the extract or bioactive diterpenes from this plant may be regarded as candidate agents of antifungal agrochemicals for crop protection products.