Investigation of the Stability of Methylammonium Lead Iodide (MAPbI3) Film Doped with Lead Cesium Triiodide (CsPbI3) Quantum Dots under an Oxygen Plasma Atmosphere.

In this study, we describe composited perovskite films based on the doping of lead cesium triiodide (CsPbI3) quantum dots (QDs) into methylammonium lead iodide (MAPbI3). CsPbI3 QDs and MAPbI3 were prepared by ligand-assisted re-precipitation and solution mixing, respectively. These films were optimized by oxygen plasma treatment, and the effect of powers from 0 to 80 W on the structural properties of the composited perovskite films is discussed. The experimental results showed that the light-harvesting ability of the films was enhanced at 20 W. The formation of the metastable state (lead(II) oxide and lead tetroxide) was demonstrated by peak differentiation-imitating. A low power enhanced the quality of the films due to the removal of organic impurities, whereas a high power caused surface damage in the films owing to the severe degradation of MAPbI3.

Reset-Voltage Controlled Resistance-State and Applications of Forming-Free Fe-Doped SrTiO3 Thin-Film Memristor.

In this study, we prepared a strontium ferrite titanate (STF) thin film using a sol-gel process to insulate resistive random-access memory (RRAM) applications. Compared to the typical strontium titanate (STO) RRAM, the improvement in the resistive switching characteristics in STF RRAM is obvious. The Al/STO/ITO/Glass RRAM set/reset voltages of -1.4 V/+3.3 V and the Al/STF/ITO/Glass RRAM set/reset voltages of -0.45 V/+1.55 V presented a memory window larger than 103, a low operating voltage and device stability of more than 104 s. In this study, the influence of Fe on the conducting paths and the bipolar resistive switching properties of Al/STF/ITO/Glass RRAM devices is investigated.

Activation Energy and Bipolar Switching Properties for the Co-Sputtering of ITOX:SiO2 Thin Films on Resistive Random Access Memory Devices.

Activation energy, bipolar resistance switching behavior, and the electrical conduction transport properties of ITOX:SiO2 thin film resistive random access memory (RRAM) devices were observed and discussed. The ITOX:SiO2 thin films were prepared using a co-sputtering deposition method on the TiN/Si substrate. For the RRAM device structure fabrication, an Al/ITOX:SiO2/TiN/Si structure was prepared by using aluminum for the top electrode and a TiN material for the bottom electrode. In addition, grain growth, defect reduction, and RRAM device performance of the ITOX:SiO2 thin film for the various oxygen gas flow conditions were observed and described. Based on the I-V curve measurements of the RRAM devices, the turn on-off ratio and the bipolar resistance switching properties of the Al/ITOX:SiO2/TiN/Si RRAM devices in the set and reset states were also obtained. At low operating voltages and high resistance values, the conductance mechanism exhibits hopping conduction mechanisms for set states. Moreover, at high operating voltages, the conductance mechanism behaves as an ohmic conduction current mechanism. Finally, the Al/ITOX:SiO2/TiN/Si RRAM devices demonstrated memory window properties, bipolar resistance switching behavior, and nonvolatile characteristics for next-generation nonvolatile memory applications.

First Order Rate Law Analysis for Reset State in Vanadium Oxide Thin Film Resistive Random Access Memory Devices.

In the reset state, the decay reaction mechanism and bipolar switching properties of vanadium oxide thin film RRAM devices for LRS/HRS are investigated and discussed here. To discover the properties of I-V switching curves, the first order rate law behaviors of the reset state between the resistant variety properties and the reaction time were observed. To verify the decay reaction mechanism in the reset state, vanadium oxide thin films from RRAM devices were measured by different constant voltage sampling and exhibited the same decay reaction rate constant. Finally, the electrical conduction transfer mechanism and metallic filament forming model described by I-V switching properties of the RRAM devices were proven and investigated.

Tff2 defines transit-amplifying pancreatic acinar progenitors that lack regenerative potential and are protective against Kras-driven carcinogenesis.

While adult pancreatic stem cells are thought not to exist, it is now appreciated that the acinar compartment harbors progenitors, including tissue-repairing facultative progenitors (FPs). Here, we study a pancreatic acinar population marked by trefoil factor 2 (Tff2) expression. Long-term lineage tracing and single-cell RNA sequencing (scRNA-seq) analysis of Tff2-DTR-CreERT2-targeted cells defines a transit-amplifying progenitor (TAP) population that contributes to normal homeostasis. Following acute and chronic injury, Tff2+ cells, distinct from FPs, undergo depopulation but are eventually replenished. At baseline, oncogenic KrasG12D-targeted Tff2+ cells are resistant to PDAC initiation. However, KrasG12D activation in Tff2+ cells leads to survival and clonal expansion following pancreatitis and a cancer stem/progenitor cell-like state. Selective ablation of Tff2+ cells prior to KrasG12D activation in Mist1+ acinar or Dclk1+ FP cells results in enhanced tumorigenesis, which can be partially rescued by adenoviral Tff2 treatment. Together, Tff2 defines a pancreatic TAP population that protects against Kras-driven carcinogenesis.

Porous SiO2/MgF2 broadband antireflection coatings for superstrate-type silicon-based tandem cells.

The purpose of this study is to reduce the glass substrate reflectivity over a wide spectral range (400-1200 nm) without having high reflectivity in the near-infrared region. After making porous SiO2/MgF2 double-layer antireflection (DLAR) thin film structure, the superstrate-type silicon-based tandem cells are added. In comparison to having only silicon-based tandem solar cells, the short-circuit current density has improved by 6.82% when porous SiO2/MgF2 DLAR thin film is applied to silicon-based tandem solar cells. This study has demonstrated that porous SiO2/MgF2 DLAR thin film structure provides antireflection properties over a broad spectral range (400-1200 nm) without having high reflectivity at near-infrared wavelengths.

Heterogeneity affects the differentiation potential of dental follicle stem cells through the TGF-ß signaling pathway.

Adult mesenchymal stem cells play an important role in maintaining organ homeostasis owing to their unique ability to generate more specialized cell populations in a coordinated manner. Adult mesenchymal stem cells are heterogeneous, a feature that is essential for their functions. However, studies have not elucidated how heterogeneity of mesenchymal stem cells affects their differentiation capacity. The current study thus explored the heterogeneous Dental Follicle Stem Cells (DFSCs). A previous study by our research group reported that selecting sub-clones can cause artificial damage of the heterogeneous microenvironment of DFSCs. The finds showed a decrease in differentiation capacity of the three subclones, although the underlying mechanism was not elucidated. In this study, cells were harvested and prepared for gene expression microarray analysis. Sequence data was used in gene ontology and pathway enrichment analysis. The results showed that downregulation of the TGF-ß signaling pathway was the main cause of changes in differentiation of sub-clones. Additional analyses revealed that the Hippo pathway, WNT pathway and signaling pathways regulating the pluripotency of stem cells were also implicated in these changes, through a cross talk with TGF-ß signaling pathway through Bmp2, Bmp4, and Bambi. In vivo implantation experiments and osteogenic induction showed that differentiation capacity of DFSCs was significantly reduced in the sub-clones. In summary, the findings of the current study show that differentiation potential of DFSCs is correlated with the heterogeneous microenvironment and TGF-ß signaling pathway significantly modulates these biological processes.

Human epidermal growth factor receptor 2-positive metastatic breast cancer with novel epidermal growth factor receptor -ZNF880 fusion and epidermal growth factor receptor E114K mutations effectively treated with pyrotinib: A case report.

INTRODUCTION: In about 15% to 20% of breast cancer cases, human epidermal growth factor receptor 2 (HER2) over-expression or gene-amplification is associated with poor prognosis. Thanks to the development of target therapies, HER2 positive patients can be managed using HER2-targeting drugs. There are several kinds ofHER2 inhibitors, such as trastuzumab, lapatinib, and pyrotinib. Pyrotinib which exert different functions, of note, the latest generation of the drug, is an irreversible small-molecule tyrosine kinase inhibitor targeting epidermal growth factor receptor (EGFR) (HER1) and/or HER2 and/or HER4. Both lapatinib and pyrotinib potentially target EGFR and/or HER2, but in some instances, induces different responses of patients with EGFR and/or HER2 mutations. This is attributed to the different mutations in EGFR and HER2 genes, which may form distinct types of HER2 dimers, with different binding capacities to drugs. PATIENT CONCERNS: Five years ago, a patient underwent a radical mastectomy in an external hospital. Results of the resection histopathology revealed an invasive ductal carcinoma, pT3N0M0, stage IIB, HER2 positive. The lady patient received 6 cycles of adjuvant chemotherapy and was subjected to adjuvant trastuzumab therapy for 1 year. After a regular 1-year follow-up and in March 2018, she complained of chest pain and visited our hospital. We diagnosed her with metastatic breast cancer, positive for HER2. DIAGNOSIS: positron emission tomography/computed tomography showed multiple metastases in the lung and sternum, while the breast lesions did not progress, the curative effect of which we evaluated as a progressive disease. Then, lapatinib integrated with chemotherapy was administered to the patient. After 5 cycles of the treatment, the patient experienced lower back pain. Through CT examination, it was revealed that she had multiple metastases in the lung and sternum, in addition to new metastases in the lumbar spine and right lobe of the liver. Moreover, magnetic resonance imaging revealed multiple metastases in the brain, and the disease further progressed. The results of circulating tumor DNA assays showed that other than HER2 amplification, novel EGFR-ZNF880 fusion and EGFR E114K mutations developed. INTERVENTIONS: The patient was administered with a combination of pyrotinib with chemotherapy. OUTCOMES: After 2 months of pyrotinib treatment, the metastases of the lung, sternum, lumbar spine, and right lobe of the liver disappeared. Also, the size of the brain metastases reduced while bone metastases were relieved. The curative effect was evaluated as a partial response. Following the results of circulating tumor DNA assays, HER2 amplification, EGFR-ZNF880 fusion, and EGFR E114K mutations disappeared. However, since a small lesion was present in the brain, the patient was subjected to radiotherapy in the head. Notably, after 9 months treatment with pyrotinib, enhanced CT indicated that tumors in the breast, liver, both lungs, brain, and bone were under control. The patient continually received oral pyrotinib, however, a new brain lesion appeared 6 months later. Overall, we managed to regulate the efficacy of pyrotinib for up to 15 months. CONCLUSION: This case report demonstrates that EGFR-ZNF880 fusion and EGFR E114K mutations may contribute or lead to the formation of a special HER2 dimer, which is rapidly resistant to lapatinib but sensitive to pyrotinib. Of note, this is the first report that such a new fusion has been found.

A novel embolic microspheres with micro nano binary progressive structure for transarterial chemoembolization applications.

In this work, a novel embolic microspheres with micro nano binary progressive structure (MN-Ms) were developed for transarterial chemoembolization (TCE) applications. The Bletilla striata polysaccharide (Bsp) polymer can inhibit neovascularization and having a dimensional porous network structure, which as the first level of micron structure (microspheres) and will play a role on tumor embolization and inhibition of ischemia-induced neovascularization. The nano flexible liposomes which were embedded by the Bsp polymer microspheres as the second level nano structure to deliver drug across biological membrane barriers. And the micro nano binary progressive structure of MN-Ms was easily formed by using an emulsion crosslinking method. The MN-Ms appeared as perfect round shape with desired swelling and suspensibility characteristics, this was very convenient for embolizing operation by TCE. Due to the binary progressive structure, the MN-Ms could effectively site-specific delivery drug to the targeted liver tissue by enhancing the permeability of Sodium dimethyl-cantharidate (SC) across vessel walls & tissue matrix and delaying drug release at the site of administration, this caused the administrated SC mostly accumulated in the liver, also a higher cytotoxicity to human hepatoma cells. This work indicate that the MN-Ms may be a promising embolic agent for TCE applications for advanced liver cancer.

Direct bonding of recessed-structure SAW filter on silicon substrate.

A procedure for fabricating a recessed surface acoustic wave (SAW) device coupled with silicon substrate is reported. The recessed structure is stable and rugged enough against the bonding process, and it can be applied to integrate a semiconductor device into one chip by a direct bonding technique. In this paper, the tensile strength of silicon (Si)-to-recessed-SAW filter is measured, and the performance of the device is discussed.

Proton-exchanged wet etching of recessed-structure SAW filter.

An improved method for fabricating recessed-structure surface acoustic wave (SAW) filters is reported. The relation between proton-exchanged duration and etched depth are studied, as well as the relation between internal reflection, etched depth, and thickness of the aluminum electrode. Experimental results show that the devices have superior performance, and ideas for further improvement of the fabricated SAW device are discussed.