Preparation of Sol-Gel-Derived CaO-B2O3-SiO2 Glass/Al2O3 Composites with High Flexural Strength and Low Dielectric Constant for LTCC Application.

Low-temperature co-fired ceramic (LTCC) substrate materials are widely applied in electronic components due to their excellent microwave dielectric properties. However, the absence of LTCC materials with a lower dielectric constant and higher mechanical strength restricts the creation of integrated and minified electronic devices. In this work, sol-gel-derived CaO-B2O3-SiO2 (CBS) glass/Al2O3 composites with high flexural strength and low dielectric constant were successfully prepared using the LTCC technique. Among the composites sintered at different temperatures, the composites sintered at 870 °C for 2 hours possess a dielectric constant of 6.3 (10 GHz), a dielectric loss of 0.2%, a flexural strength of 245 MPa, and a CTE of 5.3 × 10-6 K-1, demonstrating its great potential for applications in the electronic package field. By analyzing the CBS glass' physical characteristics, it was found that the sol-gel-derived glass has an extremely low dielectric constant of 3.6 and does not crystallize or react with Al2O3 at the sintering temperature, which is conducive to improving the flexural strength and reducing the dielectric constant of CBS glass/Al2O3 composites.

Random lasing carbon dot fibers for multilevel anti-counterfeiting.

Random lasers, which achieve light amplification through random light scattering in disordered laser gain medium, have found widespread applications in varieties of areas due to the convenient design of laser cavities. In this work, carbon dot fibers with superior fluorescence stability under a high temperature or high humidity environment are fabricated by using a single-step partial thermal decomposition method. Random lasers, which are used for multilevel anti-counterfeiting, are achieved from different types of carbon dot fibers by 370 nm excitation at room temperature. Multilevel anti-counterfeiting is realized by tuning the lasing spectra (between ∼428 and 560 nm) and threshold (between ∼2 and 25 mJ cm-2) at designated decomposition times and fiber diameters. It is extremely difficult to counterfeit lasing spectra and the specific laser threshold simultaneously. As a result, this will comprehensively improve system safety.

Ultralow Threshold Lasing from Carbon Dot-Ormosil Gel Hybrid-Based Planar Microcavity.

The absence of an ideal solid matrix with resistance to harsh conditions for carbon dots (CDs) and high transmittance in the visible/near infrared region is the bottleneck in CD applications. In this study, we show that a stable rigid structure can be formed between CDs and organically modified silicates (ormosil) gel when CDs are incorporated into ormosil gel hybrids as a solid matrix. A high photoluminescence quantum yield (PLQY) of 63% is achieved at a 583 nm emission. Peak optical gain of the hybrids was found to be 67 cm-1 at peak wavelength. Ultralow threshold (~70 W/cm2) lasing can also be demonstrated from a planar microcavity by using CD-ormosil gel hybrids as a gain medium.

Transformation of random lasing to Fabry-Perot lasing: observation of high temperature lasing from carbon dots.

Carbon dots (CDs), a subject of academic research, have attracted intense attention due to their intrinsic merits of high stability, low cost, and low toxicity. However, the absence of highly efficient red-emitting CDs restricts their application in a variety of areas including lasers. In this work, red emissive CDs (R-CDs) with a quantum yield as high as 66.7% were prepared using 1,3-dihydroxynaphthalene as the initial source. It is found that the superior optical properties of R-CDs are attributed to the high oxidation degree and high ratio of hydroxyl functional groups on the surface of CDs. Red emissive random lasing at 612 nm was realized from a microcavity by using the R-CDs/epoxy composite as the gain medium at room temperature. Simultaneously, the transformation of random lasing to Fabry-Perot lasing in the same laser cavity at 250 °C was observed. This is on account of the declining optical gain which is insufficient to support random lasing in the microcavity at high temperatures. As a result, CD based Fabry-Perot lasing was achieved at a temperature as high as 250 °C for the first time.

Xiaoyaosan, a traditional Chinese medicine, inhibits the chronic restraint stress-induced liver metastasis of colon cancer in vivo.

CONTEXT: Xiaoyaosan (XYS), a traditional Chinese medicine (TCM), has been widely used to relieve a variety of disorders caused by depression. OBJECTIVE: This study evaluates the effect of XYS against tumour metastasis in a chronic restraint stress mouse model. METHODS AND MATERIALS: Forty C57BL/6J mice were randomly divided into four groups, including blank-control (BC), blank-stress (BS), XYS-control (XC) and XYS-stress (XS). BS and XS groups were exposed to immobilization stress for 2 h per day for 28 days commencing seven days before tumour cell injection. XC and XS groups were given a gavage of XYS (1516.67 mg/kg) before chronic immobilization stress. Mice were injected with HT-29 colon cancer cells in the spleen to produce liver metastasis. After 28 days of injecting with HT-29 cells, flow cytometry, western blot, PCR and immunohistochemical staining were performed to uncover the role of chronic restraint stress and XYS in the liver metastasis of colon cancer. RESULTS: Metastatic liver weight of mice in XS group (3.33 ± 0.18 g) was significantly lower than BS group (4.01 ± 0.27 g). Chronic restraint stress significantly increased CD11b+F4/80+ and CD11b+GrloLy6Chi cell infiltration. XYS treatment significantly decreased the CD11b+F4/80+ tumour-associated macrophage (TAM) population and CD11b+GrloLy6Chi myeloid-derived suppressor cell (MDSC). TGF-ß, IL-6, MMP-9 and VEGF in spleen tumours significantly decreased in XYS group. XYS also reduced VEGF and CD31 in hepatic metastatic tissue, which were elevated by chronic restraint stress. CONCLUSIONS: XYS may successfully inhibit chronic-stress-induced liver metastasis. Results suggest that XYS may have therapeutic value for colorectal cancer treatment.

WD-3 inhibits the proliferation of breast cancer cells by regulating the glycolytic pathway.

Number 3 Prescription (WD-3) is an herbal remedy used in traditional Chinese medicine that has been shown to improve the outcomes of patients with advanced colon and gastric cancers. This study aimed to investigate the effect of WD-3 on proliferation, glycolysis, and hexokinase 2 expression in breast cancer cells. Four breast cancer cell lines (MDA-MB-231, BT-549, MCF-7, and MCF-7/ADR-RES) were treated with different concentrations of WD-3 compared with blank control (phosphate-buffered saline). Each of the breast cancer cell lines was also divided into WD-3, paclitaxel, and blank control group. Cell proliferation and morphology were assessed by MTT assay, nuclear Hoechst 33258 staining, or immunofluorescence. Apoptosis was analyzed by flow cytometry. High performance liquid chromatography was used for measurement of ATP, ADP, and AMP. Hexokinase 2 expression was analyzed by Western blot and quantitative reverse transcription PCR. WD-3 inhibited proliferation and increased apoptosis in all four breast cancer cell lines, in a dose-dependent manner. ATP and EC (energy charge) were significantly decreased in WD-3-treated BT-549 and MDA-MB-231 cells. WD-3 significantly downregulated the protein and mRNA expression of hexokinase II in BT-549 cells, however, not in the other three breast cancer cell lines. Our findings indicate that WD-3 targets the glycolytic pathway in breast cancer cells to exert its antitumor activity.

Highly efficient and ultra-narrow bandwidth orange emissive carbon dots for microcavity lasers.

Luminescent materials with high efficiency, narrow emission bandwidth and long emission wavelength have attracted extensive attention in recent years. However, for novel luminescent carbon dots, it is still a major challenge to obtain these properties simultaneously. Here, this type of carbon dot was proposed using 1,4-diaminonaphthalene as the initial source. The carbon dots demonstrate strong orange emission with the highest quantum yield of 82% and an extremely narrow emission bandwidth of 30 nm. It is found that the orange emission of carbon dots is attributed to the high defect amounts including nitrogen and oxygen doping. The high carboxyl group content leads to a high efficiency and the uniform size distribution results in a narrow bandwidth. The carbon dots are used as the gain medium of a whispering gallery mode microcavity laser. A low excitation threshold of 12 kW cm-2 and a high quality factor of ∼3600 can be obtained from the microcavity lasers. This work has provided a didactic example to develop high-quality long emission-wavelength carbon dots with strong emission and an ultra-narrow emission bandwidth, which makes it possible to expand the application of original and high-performance lasers or other optical devices.

Realization of Lasing Emission from One Step Fabricated WSe2 Quantum Dots.

Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) quantum dots (QDs) are the vanguard due to their unique properties. In this work, WSe2 QDs were fabricated via one step ultrasonic probe sonication. Excitation wavelength dependent photoluminescence (PL) is observed from WSe2 QDs. Room-temperature lasing emission which benefits from 3.7 times enhancement of PL intensity by thermal treatment at ~470 nm was achieved with an excitation threshold value of ~3.5 kW/cm² in a Fabry⁻Perot laser cavity. To the best of our knowledge, this is the first demonstration of lasing emission from TMDCs QDs. This indicates that TMDCs QDs are a superior candidate as a new type of laser gain medium.

Realization of multiphoton lasing from carbon nanodot microcavities.

The use of organosilane chains to link carbon nanodots (CDs) through organosilane surface functional groups is proposed to improve the efficiency of multiphoton absorption. As a result, a large absorption coefficient of 1.16 × 10-6 cm5 per GW3 is obtained and four-photon luminescence under 1900 nm excitation is observed from the CDs at room temperature. Furthermore, a CD laser, which demonstrates random lasing under three-photon (i.e. 1400 nm) excitation, can be realized by sandwiching a CD film between a quartz substrate and a dielectric mirror. The formation of strongly confined microcavities, which arise from the non-uniform distribution of refractive indices inside the CD film, is attributed to the realization of lasing emission.