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Background: The role of long non-coding RNA (lncRNA) small nucleolar RNA host gene 15 (SNHG15) in cisplatin-resistance was studied in gastric cancer. Methods: The relative SNHG15 expression and its correlation with survival were assayed on the Cancer Genome Atlas data and confirmed with the clinical samples we collected. Cisplatin-resistant MKN45 cell line (MKN45 CR) was established. SNHG15 plasmid and SNHG15 shRNA plasmid were transfected into MKN45 cells and MKN45 CR cells. Colony formation analysis and cell counting kit-8 assay were utilized to determine cell proliferation and viability. The binding between SNHG15 and zeste 2 polycomb repressive complex 2 subunit (EZH2) was testified with RNA immunoprecipitation (RIP). The promoter activity of phosphatase and tensin homolog (PTEN) was evaluated by luciferase reporter assay. Results: High SNHG15 expression was correlated with the poor overall survival of gastric cancer patients, and cisplatin treatment can induce time and dose-dependent up-regulation of SNHG15. At the same time, SNHG15 overexpression could promote the cisplatin resistance, while SNHG15 inhibition could diminish the cisplatin resistance. RIP assays confirmed the interaction of SNHG15 with EZH2. More importantly, SNHG15 inhibited PTEN promoter activity by reducing EZH2 recruitment in MKN45 CR cells. Conclusion: SNHG15 epigenetically prohibits PTEN expression by recruiting EZH2 in gastric cancer cisplatin-resistant cells.

Organic–inorganic hybrid metal halides for high-temperature phase transition have become increasingly popular owing to their wide operating temperature range in practical applications, e.g., energy storage, permittivity switches and opto-electronic devices. This paper describes the subtle assembly of two new hybrid perovskite crystals, [Cl-C6H4-(CH2)2NH3]2CdX4 (X = Br 1; Cl 2), undergoing high-T reversible phase transformations around 335 K/356 K. Differential scanning calorimetry (DSC), differential thermal analysis (DTA) and VT PXRD tests uncover their reversible first-order phase transition behaviors. Furthermore, the compounds exhibit switchable dielectricity near T, making them potential dielectric switching materials. Hirshfeld surface analysis well discloses a distinct difference in hydrogen-bonding interaction between 1 and 2. UV spectra and computational analysis demonstrate that the compounds are a type of direct-band-gap semiconductor. This research will contribute an effective approach to the structure and development of multifunctional molecular hybrid crystals. [ABSTRACT FROM AUTHOR]

Materials combining high-temperature phase transformation and fluorescence properties are not abundant, especially, stator–rotator-type inclusion compounds possessing excellent optical properties are extremely rare. In this study, a neoteric high-temperature crown ether inclusion luminophor: [(2,4,6-trifluoroanilinium)-(18-crown-6)][BF4] (1) was constructed, undergoing a reversible phase transition near Tp = 364 K. Differential thermal analysis (DTA), specific heat capacity (Cp) and differential scanning calorimetry (DSC) tests disclosed a reversible first-order phase transformation behavior of 1. Multiple-temperature PXRD analyses further demonstrated a structural transition from low- to high-symmetry. Permittivity tests for 1 exhibited a prominent step-like dielectric response near Tp, indicating that it is a promising dielectric switching material. Besides, 1 occupies a broad optical energy band of ca. 4.45 eV. The photoluminescence tests for 1 display a strong luminescence emission peak at 368 nm. Further research and computational analysis showed that the luminescence lifetime of 1 reaches up to 43.998 μs. The investigation opens up an alternative avenue to construct and synthesize phase-transition compounds possessing high-Tp and superior optical properties. [ABSTRACT FROM AUTHOR]

The extract of Ginkgo biloba leaf is a popular herbal product or dietary supplement in the world to treat various diseases, and flavonol glycosides are considered as the main bioactive constituents. In this study, 37 flavonol glycosides were rapidly screened out by precursor ion scanning in positive ion mode with production ions at m/z 287.05, 303.05, and 317.06. Subsequently, a reliable and sensitive ultra‐high‐performance liquid chromatography coupled with triple quadrupole‐linear ion trap mass spectrometry approach was established and validated to quantify the 20 prototype flavonol glycosides in rat plasma. Calibration curves showed good linearity (R2 ≥ 0.9894) over the corresponding concentration range. The precision, accuracy, extraction recovery, matrix effect, and stability were also satisfactory. The validated method was successfully applied to a pharmacokinetic study of prototype flavonol glycosides in rat after oral administration of the extract of G. biloba leaf. As a result, the Tmax of flavonol glycosides was short at 0.11–0.60 h. Quercetin‐3‐O‐(2",6″‐di‐O‐rhamnosyl)‐glucoside, kaempferol‐3‐O‐(2′',6′'‐di‐O‐rhamnosyl)‐glucoside, quercetin‐3‐O‐rutinoside, quercetin‐ 3‐O‐glucosyl‐(1‐2)‐O‐rhamnoside, and kaempferol‐3‐O‐glucoside presented relatively high systemic exposure levels with AUC0‐∞ > 500 μg h/L and Cmax > 100 μg/L. This study would provide the valuable information for further scientific research and clinical application of the extract of G. biloba leaf. [ABSTRACT FROM AUTHOR]

Molecular ferroelectrics of high‐temperature reversible phase transitions are very rare and have attracted increasing attention in recent years. In this paper is described the successful synthesis of a novel high‐temperature host‐guest inclusion ferroelectric: [(C6H5NF3)(18‐crown‐6)][BF4] (1) that shows a pair of reversible peaks at 348 K (heating) and 331 K (cooling) with a heat hysteresis about 17 K by differential scanning calorimetry measurements, thus indicating that 1 undergoes a reversible structural phase transition. Variable‐temperature PXRD and temperature‐dependent dielectric measurements further prove the phase‐transition behavior of 1. The second harmonic response demonstrates that 1 belongs to a non‐centrosymmetric space group at room temperature and is a good nonlinear optical material. In its semiconducting properties, 1 shows a wide optical band gap of about 4.43 eV that comes chiefly from the C, H and O atoms of the crystals. In particular, the ferroelectric measurements of 1 exhibit a typical polarization‐electric hysteresis loop with a large spontaneous polarization (Ps) of about 4.06 μC/cm2. This finding offers an alternative pathway for designing new ferroelectric‐dielectric and nonlinear optical materials and related physical properties in organic‐inorganic and other hybrid crystals. [ABSTRACT FROM AUTHOR]

Response time of optical microfiber temperature sensor is investigated based on the microfiber modal interferometer (MMI). Sensitivity of −406pm/°C is obtained in temperature sensing, which is one order higher than those of fiber Bragg gratings (FBGs) and microfiber resonators, and response time of 13.1ms is measured, which is twice as fast as FBGs. Based on the theoretical expression of time constant in temperature sensing, dependences of response time on many factors, such as heat transfer coefficient, fiber diameter and ambient temperature are investigated, respectively. In addition, relationship of time constant and response time, dependence of response time on detection device or fiber length, and repeatability of sensor are also discussed. Results demonstrated here may afford some useful references for optical sensors used in obtaining temperature profile and transient process in seawater or analyzing temporal response of temperature sensors in other liquid surroundings. [ABSTRACT FROM AUTHOR]