Simultaneous Passivation of Perovskite Interfaces at Multiple Active Sites Improves Device Performance: Combining Theory and Experiment.

A multisite interface passivation material named 2-mercapto-4-methyl-5-thiazoleacetic acid (MMTA) is used to optimize the perovskite film top interface. DFT calculations and experiments show that MMTA can effectively passivate interface defects. Finally, the champion device's photoelectric conversion efficiency reached 23.44%, which possessed long-term stability.

Functionalized polymer modified buried interface for enhanced efficiency and stability of perovskite solar cells.

Although great progress has been made in perovskite solar cells (PCSs), further development of PCSs is hindered by a large number of defects, nonradiative recombination, and mysterious stresses. Here, we propose a new interfacial strategy by introducing a new polymer material named povidone-iodine (PV-I) as a buffer layer. A series of studies indicate that the introduced buffer layer can form a strong chemical interaction with SnO2 and the perovskite, which can not only passivate the defects of the two functional layers but also strengthen the interfacial connection. The reduction of film defects and the enhancement of interface connection are beneficial to the extraction and transport of the carrier. In addition, the introduction of a buffer layer releases the interfacial stress. Ultimately, we achieved attractive efficiency (22.02%, 0.1 cm2) and considerable long-term stability (after aging 500 h, the target device still retains 81% of its original PCE). The excellent performance of the device indicates that this strategy can be used as an effective control method for perovskite solar cells to facilitate their commercialization.

Low-Temperature Processed Brookite Interfacial Modification for Perovskite Solar Cells with Improved Performance.

The scaffold layer plays an important role in transporting electrons and preventing carrier recombination in mesoporous perovskite solar cells (PSCs), so the engineering of the interface between the scaffold layer and the light absorption layer has attracted widespread concern. In this work, vertically grown TiO2 nanorods (NRs) as scaffold layers are fabricated and further treated with TiCl4 aqueous solution. It can be found that a thin brookite TiO2 nanoparticle (NP) layer is formed by the chemical bath deposition (CBD) method on the surface of every rutile NR with a low annealing temperature (150 °C), which is beneficial for the infiltration and growth of perovskite. The PSC based on the TiO2 NR/brookite NP structure shows the best power conversion of 15.2%, which is 56.37% higher than that of the PSC based on bare NRs (9.72%). This complex structure presents an improved pore filling fraction and better carrier transport capability with less trap-assisted carrier recombination. In addition, low-annealing-temperature-formed brookite NPs possess a more suitable edge potential for electrons to transport from the perovskite layer to the electron collection layer when compared with high-annealing-temperature-formed anatase NPs. The brookite phase TiO2 fabricated at a low temperature presents great potential for flexible PSCs.

Crystal Orientation Modulation and Defect Passivation for Efficient and Stable Methylammonium-Free Dion-Jacobson Quasi-2D Perovskite Solar Cells.

Dion-Jacobson (DJ) quasi-2D perovskite solar cells (PSCs) have received increasing attention due to their greater potentials in realizing efficient and stable quasi-2D PSCs relative to their Ruddlesden-Popper counterpart. The substitution of methylammonium (MA+) with formamidinium is expected to be able to further increase the stability and power conversion efficiency (PCE) of DJ quasi-2D PSCs. Herein, we report a multifunctional additive strategy for preparing high-quality MA-free DJ quasi-2D perovskite films, where 1,1'-carbonyldi(1,2,4-triazole) (CDTA) molecules are incorporated into the perovskite precursor solution. CDTA modification can control phase distribution, enlarge grain size, modulate crystallinity and crystal orientation, and passivate defects. After CDTA modification, more favorable gradient phase distribution and accordingly gradient band alignment are formed, which is conducive to carrier transport and extraction. The improved crystal orientation can facilitate carrier transport and collection. The enlarged grain size and effective defect passivation contribute to reduced defect density. As a result, the CDTA-modified device delivers a PCE of 16.07%, which is one of the highest PCEs ever reported for MA-free DJ quasi-2D PSCs. The unencapsulated device with CDTA maintains 92% of its initial PCE after aging under one sun illumination for 360 h and 86% after aging at 60 °C for 360 h.

Natural Polyphyllins (I, II, D, VI, VII) Reverses Cancer Through Apoptosis, Autophagy, Mitophagy, Inflammation, and Necroptosis.

Cancer is the second leading cause of mortality worldwide. Conventional therapies, including surgery, radiation, and chemotherapy, have limited success because of secondary resistance. Therefore, safe, non-resistant, less toxic, and convenient drugs are urgently required. Natural products (NPs), primarily sourced from medicinal plants, are ideal for cancer treatment because of their low toxicity and high success. NPs cure cancer by regulating different pathways, such as PI3K/AKT/mTOR, ER stress, JNK, Wnt, STAT3, MAPKs, NF-kB, MEK-ERK, inflammation, oxidative stress, apoptosis, autophagy, mitophagy, and necroptosis. Among the NPs, steroid saponins, including polyphyllins (I, II, D, VI, and VII), have potent pharmacological, analgesic, and anticancer activities for the induction of cytotoxicity. Recent research has demonstrated that polyphyllins (PPs) possess potent effects against different cancers through apoptosis, autophagy, inflammation, and necroptosis. This review summarizes the available studies on PPs against cancer to provide a basis for future research.

Alantolactone induces apoptosis in THP-1 cells through STAT3, survivin inhibition, and intrinsic apoptosis pathway.

Cancer is the second foremost cause of mortality in the world, and THP-1 cells play an important role in cancer progression. Alantolactone (ALT), a sesquiterpene lactone compound derived from Inula helenium, has a number of biological activities including antibacterial, antifungal, and anticancer. The current study was conducted to investigate the effects of ALT on THP-1 cells and its underlying molecular mechanisms. THP-1 cells were cultured and treated with ALT (20, 40 µM) for 12 hr, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell morphology, live/dead, and apoptosis assays were performed. The gene expressions at the protein level were checked through Western blot. Results show that ALT decreased cell viability and increased cell death and apoptosis. We found that ALT inhibited STAT3 and survivin expression. Furthermore, ALT induced mitochondrial-dependent apoptosis through a decrease in B-cell lymphoma-2 (Bcl-2) and Bcl-xL and increase in Bax expression, resulting in the release of cytochrome c (Cyt-c) from mitochondria. Cyt-c release from mitochondria further increased cleaved (cl) caspase-3 and cl-PARP expression and led the cells to apoptosis. Therefore, ALT might be a good therapy for the progression due to THP-1 cells.

ß-Elemene Enhances the Chemotherapeutic Effect of 5-Fluorouracil in Triple-Negative Breast Cancer via PI3K/AKT, RAF-MEK-ErK, and NF-κB Signaling Pathways.

BACKGROUND: The most common chemotherapeutic drug for triple-negative breast cancer (TNBC) treatment is 5-fluorouracil (5-FU), but its therapeutic index is low due to its toxicity. ß-Elemene (ELE) possesses antitumor activity against different cancers, but it has never been used in combination with 5-FU to improve its chemotherapeutic effect against TNBC. MATERIALS AND METHODS: We treated MDA-MB-231 and BT549 cells of TNBC with ELE alone, 5-FU alone, or their combination to investigate their treatment effects on cell viability, proliferation, migration, invasion, and colony formation. We verified the molecular mechanisms of our results through confocal immunofluorescence, immunohistochemistry, and Western blot analysis in vitro and in vivo. RESULTS: Our result revealed that ELE enhanced the 5-FU effect against cell viability, proliferation, migration, invasion, and colony formation through different mechanisms in MDA-MB-231 and BT549 cell lines. In molecular mechanisms, ELE and 5-FU in combination enhances apoptosis in both cell lines through Bl-2 family protein and caspase cascade modulation, thereby inhibiting NF-kB pathway through IKKß, IKKα, and p65 downregulation in the cytoplasm and p50 and p65 downregulation in the nucleus. ELE and 5-FU in combination regulated the PI3K/AKT pathway through p-AKT, P-85, p110r, p-PDK1, and p110a protein and RAF-MEK-ERK pathway inhibition through the p-c-raf and p-ERK downregulation. The PI3K inhibitor LY294002 or RAF-MEK-ERK inhibitor U0126 in combination with ELE and 5-FU decreased cell viability in both cell lines significantly, thereby showing the involvement of these pathways in cell apoptosis. In mouse xenograft model, ELE and 5-FU in combination inhibited the tumor growth and modulated its molecular markers. CONCLUSION: The conclusion obtained, considering that the results suggest that the combination may be important specifically in the treatment of TNBC.

Natural gypenosides: targeting cancer through different molecular pathways.

The second foremost cause of mortality around the word is cancer. Conventional therapies, such as radiation, surgery, and chemotherapy have limited accessibility owing to secondary resistance. Therefore, convenient, safe, and nonresistant drugs are urgently needed. Plant-derived natural products have attracted considerable interest owing to their high efficacy, low toxicity, and convenience. Gypenosides (Gyp) inhibit invasion, migration, metastasis, and proliferation and induce apoptosis in different cancers, including oral, lung, colorectal, hepatocellular, and leukemic cancers through different molecular pathways. This review summarizes Gyp studies on cancer to serve as a reference for further research and clinical trials.

A case of sitosterolemia misdiagnosed as familial hypercholesterolemia: A 4-year follow-up.

Familial hypercholesterolemia (FH) is a common inherited disease that exhibits significantly increased levels of low-density lipoprotein cholesterol (LDL-C), skin or tendon xanthomas, corneal arcus and premature coronary heart disease (CHD). The prevalence of heterozygous FH is nearly 1/300 worldwide, and the prevalence of homozygous FH (HoFH) is 1/160,000 - 1/300,000. The Dutch Lipid Clinic Network diagnostic (DLCN) criteria is the most commonly recommended criteria for diagnosing FH patients. However, another disease with a similar clinical phenotype to FH must be differentiated from FH. This disease is a rare autosomal recessive disorder, sitosterolemia, and its incidence rate is approximately 1/5 million. We report a 16-month-old child with suspected HoFH and LDL-C levels that were reduced from 14.69 mmol/L to 3.24 mmol/L after dietary control without statin therapy. Gas chromatography detection of plant sterol levels and targeted exon sequencing chips for genetic testing were used to reach confirmed the diagnosis of sitosterolemia.

Enhanced photovoltaic properties of perovskite solar cells by TiO2 homogeneous hybrid structure.

In this paper, we fabricated a TiO2 homogeneous hybrid structure for application in perovskite solar cells (PSCs) under ambient conditions. Under the standard air mass 1.5 global (AM 1.5G) illumination, PSCs based on homogeneous hybrid structure present a maximum power conversion efficiency of 5.39% which is higher than that of pure TiO2 nanosheets. The enhanced properties can be explained by the better contact of TiO2 nanosheets/nanoparticles with CH3NH3PbI3 and fewer pinholes in electron transport materials. The advent of such unique structure opens up new avenues for the future development of high-efficiency photovoltaic cells.

Synthesis of uniform cadmium sulphide thin film by the homogeneous precipitation method on cadmium telluride nanorods and its application in three-dimensional heterojunction flexible solar cells.

High-density CdTe nanorod arrays are successfully embedded in a uniform and compact CdS layer, forming a novel three-dimensional (3D) CdTe NRs/CdS heterojunction structure. The CdS layer is prepared by homogeneous precipitation (HP) method using decomposition of urea. The effects of temperature and concentration of reactants on the growth and composition of CdS film are investigated in detail. The results demonstrate that the temperature affects the thermal decomposition of urea significantly, and the concentration of CdCl2 and CS (NH2)2 plays an essential role in the compositional ratio of CdS film. Further investigations reveal that, in comparison with the traditional precipitation method, a better coverage of CdS on the surface of CdTe NRs can be obtained by HP method due to the slow and even hydrolysis of urea. Moreover, photovoltaic performance of the novel CdTe NRs/CdS 3D photovoltaic device is also investigated. This study demonstrates that the 3D heterostructure has potential application in thin film solar cells, and the successful deposition of CdS layer on the surface of CdTe NRs by HP method suggests a promising technique for large-scale fabrication of these solar cells.