Investigation of the Optical Nonlinearity for Au Plasmonic Nanoparticles Based on Ion Implantation.

The Au ion implantation process has emerged as an effective and simple method to be utilized for the fabrication of opto-electronic materials and devices due to numerous fascinating features of Au nanoparticles such as surface plasmon resonance (SPR), large third-order nonlinearity and a fast response time. In this paper, we describe the fabrication of a novel Au nanoparticle saturable absorber (Au NP-SA) by embedding the Au NPs into a SiO2 thin film using the ion implantation process, which shows excellent saturable absorption features due to the localized surface plasmon resonance (LSPR) effect of Au NPs. A stable and high-quality pulsed laser with a repetition rate of 33.3 kHz and a single pulse energy of 11.7 nJ was successfully constructed with the Au NP-SA. Both the stable operation characteristic of the obtained Q-switched pulsed laser and the high repeatability of the fabrication process of the Au NP-SA were demonstrated. In addition, the simple feasibility and maturity of the ion implantation process allow for the plasmonic nanoparticles to be easily integrated into other types of opto-electronic materials and devices to further improve their performance, and shows immense potential for the production of wafer-level products.

The Pro-Tumor Biological Function of IL-36α Plays an Important Role in the Tumor Microenvironment of HCC.

Purpose: To investigate the role of IL-36 in the tumorigenesis of hepatocellular carcinoma (HCC). IL-36 composed of a natural antagonist (IL-36Ra) and three agonists (IL-36α, -ß, -γ) that stimulate inflammation by binding to a common receptor consisting of IL-36R and IL-1RAcP. HCC is a common malignancy associated with high morbidity and mortality, often diagnosed at later stages. Although the exact role of IL-36α in HCC remains controversial, it is hypothesized that it may play a significant role in the development and progression of this cancer. Materials and Methods: In the current study, we measured both circulating and intrahepatic levels of IL-36α from HCC patients and healthy controls, using ELISA. The association between IL-36 and the differentiation of HCC was determined. Furthermore, the role IL-36 in both HCC and non-HCC cell lines was evaluated in vitro. Results: Circulating and intra-hepatic IL-36α was inversely correlated with differentiation of HCC, suggesting that IL-36α contribute to protection during the development of HCC. Based on bioinformatics, miR-27b-3p is closely related to downstream IL-36α. Thus, we determined miR-27b-3p expression in HCC tissues, showing upregulated miR-27b-3p was inversely correlated with IL-36α in HCC, perhaps via CXCL1 in HCC cells. It was confirmed that IL-36α inhibited HCC proliferation, viability and migration in vitro, consistent with reduced the expression of cytokines IL-1ß, IL-18, implying that IL-36α inhibited the possible involvement of pyroptosis. Conclusion: Our data suggests that IL-36α may be a potential therapeutic target and a prediction biomarker for the management of HCC.

Carbon quantum dots with pH-responsive orange-/red-light emission for fluorescence imaging of intracellular pH.

N-doped carbon quantum dots (N-CDs) with polyaminobenzene hydrazine as precursor were prepared by solvothermal method for the monitoring of pH fluctuation in HeLa cells via fluorescence imaging. The N-CDs show two emission wavelengths at 582 and 640 nm under different pH with two excitation wavelengths. The fluorescence intensity at 640 nm (λex = 520 nm) and the ratio of F582/F640 (λex = 470 nm) linearly increase with pH in the range of 2.4 ~ 3.6 (R2 = 992) and 5.6 ~ 7.6 (R2 = 0.987), respectively. The sensor exhibits high sensitivity and reversibility and anti-interference capability, thus enabling sensing pH change in intracellular environment in real time, as demonstrated by successful monitoring of intracellular pH fluctuation during H2O2 stimulation in HeLa cells.

MOF-coated upconversion nanoconstructs for synergetic photo-chemodynamic/oxygen-elevated photodynamic therapy.

Excessive production of intracellular reactive oxygen species (ROS) can induce apoptosis of cancer cells; however, it is often limited by severe triggering conditions and hypoxic microenvironments of solid tumors. To address these issues, herein, we have designed a MOF-coated upconversion nanoconstruct (UCTSCF, referring to UC@Ce6/TFS@mSiO2@MIL-100(Cu/Fe)) for synergetic photochemodynamic therapy (PCT)/oxygen-elevated photodynamic therapy (PDT). The MOF (MIL-100(Fe)) coating with Cu-doping was designed to catalyze H2O2 overexpression in cancer cells to generate the most cytotoxic ˙OH via chemodynamic therapy (CDT). It is noted that UC, representing 808 nm driven upconversion nanoparticles with high tissue penetration depth/low over-heating effects, was designed to provide intense blue light which can relieve the severe triggering conditions of CDT via PCT. Furthermore, the functional layer of the photosensitizer chlorin e6 (Ce6) and O2-carrying triethoxy(1H,1H,2H,2H-nonafluorohexyl)silane (TFS) co-doped mesoporous silicon (Ce6/TFS@mSiO2) can cause oxygen-elevated 1O2 production upon 671 nm light irradiation. In such a simple ROS generation nanoplatform, we heighten the antitumor effect via oxygen-elevated synergetic tumor PCT/PDT.

SiO2 Passivated Graphene Saturable Absorber Mirrors for Ultrashort Pulse Generation.

Owing to its broadband absorption, ultrafast recovery time, and excellent saturable absorption feature, graphene has been recognized as one of the best candidates as a high-performance saturable absorber (SA). However, the low absorption efficiency and reduced modulation depth severely limit the application of graphene-based SA in ultrafast fiber lasers. In this paper, a single-layer graphene saturable absorber mirror (SG-SAM) was coated by a quarter-wave SiO2 passivated layer, and a significantly enhanced modulation depth and reduced saturation intensity were obtained simultaneously compared to the SG-SAM without the SiO2 coating layer. In addition, long-term operational stability was found in the device due to the excellent isolation and protection of the graphene absorption layer from the external environment by the SiO2 layer. The high performance of the SAM was further confirmed by the construction of a ring-cavity EDF laser generating mode-locked pulses with a central wavelength of 1563.7 nm, a repetition rate of 34.17 MHz, and a pulse width of 830 fs.

miR-183-5p Promotes HCC Migration/Invasion via Increasing Aerobic Glycolysis.

BACKGROUND: The mortality and morbidity of hepatocellular carcinoma (HCC) are still unacceptably high, despite decades of extensive studies. Aerobic glycolysis is a hallmark of cancer metabolism, closely relating to invasion and metastasis of HCC. MicroRNAs (miRNAs) are involved in the regulation of aerobic glycolysis. miR-183-5p, an oncogenic miRNA, is highly expressed in HCC, but the regulatory mechanism of miR-183-5p in migration, invasion and aerobic glycolysis in HCC remains unclear. PURPOSE: To elucidate whether miR-183-5p affects aerobic glycolysis to regulate the migration and invasion of HCC, and to explore its regulatory mechanism. METHODS: We attempted to observe the effects of miR-183-5p on the migration and invasion of HepG2 cells by a wound-healing assay and Transwell assays. The effect of miR-183-5p on glycolysis was determined by glucose uptake and lactate generation. Western blot and qPCR were used to detect the relevant proteins and miRNA expression. RESULTS: Our results show that miR-183-5p promoted migration and invasion, enhanced glycolysis via increasing glucose uptake and lactate generation, and up-regulated glycolysis-related gene (PKM2, HK2, LDHA, GLUT1) expression in HepG2 cells. Further experiments indicated that miR-183-5p could decrease PTEN expression, but increased Akt, p-Akt and mTOR expression in HepG2 cells. CONCLUSION: These findings suggest that miR-183-5p may promote HCC migration and invasion via increasing aerobic glycolysis through targeting PTEN and then activating Akt/mTOR signaling.

Nitrogen and fluorine co-doped green fluorescence carbon dots as a label-free probe for determination of cytochrome c in serum and temperature sensing.

As an important biomarker, the analysis of cytochrome c (Cyt c) plays a crucial role in cell-apoptosis or even cancer diagnosis. This work develops a label-free probe for Cyt c using the nitrogen and fluorine co-doped carbon dots (N, F-CDs) which were facile prepared through solvothermal method with 3, 4-difluorophenylhydrazine as precursor. The N, F-CDs have an average diameter of 3.4 nm, and can form a quite stable colloidal solution. The N, F-CDs show bright yellow-green fluorescence, excitation/emission wavelengths 475/530 nm, and a relatively high fluorescence quantum yield of 16.9%. Interestingly, the N, F-CDs indicate a linear and reversible variation of emission intensity with a sensitivity of -1.11% per ℃ in the temperature range from 25 to 60 ℃. Inner filter effect (IFE) between N, F-CDs and Cyt c turns the fluorescence of N, F-CDs from "on" to "off". The sensor possesses the excellent anti-interference ability towards the main components of plasma. Under optimum conditions, there is a linear relationship between fluorescence intensity function (F0-F) and the concentration of Cyt c in the range of 0.5-25 µΜ with a limit of detection (LOD) (S/N = 3) of 0.25 µM. Finally, the developed method has been successfully used to detect Cyt c in human serum sample with satisfactory recoveries in a range of 93.14-110.40%.

Adjusting the chromatographic properties of poly(ionic liquid)-modified stationary phases by substitution on the imidazolium cation.

Poly(ionic liquid)-modified stationary phases can have multiple interactions with solutes. However, in most stationary phases, separation selectivity is adjusted by changing the poly(ionic liquid) anions. In this work, two poly(ionic liquid)-modified silica stationary phases were prepared by introducing the cyano or tetrazolyl group on the pendant imidazolium cation on the polymer chains. Various analytes were selected to investigate their mechanism of retention in the stationary phases using different mobile phases. Two poly(ionic liquid)-modified stationary phases can provide various interactions toward solutes. Compared to the cyano-functionalized poly(ionic liquid) stationary phase, the tetrazolyl-functionalized poly(ionic liquid) stationary phase provides additional cation-exchange and π-π interactions, resulting in different separation selectivity toward analytes. Finally, applicability of the developed stationary phases was demonstrated by the efficient separation of nonsteroidal anti-inflammatory drugs.

Magnetic mesoporous nanoparticles modified with poly(ionic liquids) with multi-functional groups for enrichment and determination of pyrethroid residues in apples.

Considering that the determination of pyrethroid residues is of value for the safety of food, a new poly(ionic liquid)-functionalized magnetic mesoporous nanoparticle was designed and used as an adsorbent in magnetic solid-phase extraction for the enrichment of eight pyrethroids. The porous structure and large surface area of the mesoporous silica shell endow the adsorbent with abundant binding sites. In contrast to the reported poly(ionic liquids) with only one kind of functional group in the cationic part, the new poly(ionic liquids) with mixed cyano and phenyl groups in cationic part matched the chemical structure of the analytes to improve extraction efficiency. Under the optimum conditions, an effective method was established for the determination of eight pyrethroids in apples. Adsorption equilibrium can be quickly reached in 1 min, greatly decreasing the extraction time. The linearity range was found to be 10-200 ng/g, and the detection limits ranged from 0.24 to 1.99 ng/g. Recoveries of analytes in apple samples ranged from 87.3 to 119.0%, with relative standard deviations varying in the range of 3-21.2% (intraday) and 0.3-15.2% (interday). The results indicate that the proposed method is a good candidate for pyrethroid residues in apple samples.

[Effects of the Combination of Emodin and 3'-Azido-3'-Deoxythymidine on Proliferation and Apoptosis in leukemia KG-1a cells Transfected with Egr-1 siRNA].

OBJECTIVE: This study was aimed to investigate the effects of emodin combined with 3'-azido-3'-deoxythymidine (AZT) on proliferation and apoptosis of leukemia cell line KG-1a cells and its mechanism. METHODS: KG-1a cells were transfected with Egr-1 siRNA by electroporation and divided into blank control (KG-1a), nonspecific control (KG-1a/NC) and Egr-1 siRNA (KG-1a/siRNA) groups. Transfection efficiency was tested through fluorescence microscopy and flow cytometry and the transfection effect was detected by using qPCR. The cell proliferation rate was detected with MTT method. After the cells were treated with 10 µmol/L of emodin, 3200 or 1600 µmol/L of AZT and their combinations, the proliferation inhibition rates and the apoptosis rates of cells in 3 groups were detected with MTT method and FCM, respectively. RESULTS: The transfection efficiency of Egr-1 siRNA was found to reach more than 59.21%; as compared with blank control(KG-1a) and nonspectic control(KG-1a/NC), the cell proliferation in Egr-1 siRNA group significantly reduced (P<0.01). The combination of emodin and AZT had considerable synergistic inhibitory effects on proliferation of normal KG-1a cells and nonspecific control(KG-1a NC) cells, but the synergistic effects disappeared after Egr-1 gene silencing. CONCLUSION: The effects of the combination of emodin and AZT on proliferation and apoptosis may be related with Egr-1.

[Effects of AZT on leukemia cell line KG-1a proliferation and telomerase activity].

This study was purposed to investigate the effect of 3'-azido-2', 3'-dideoxythymidine (AZT)on the proliferation and telomerase activity of human acute myeloid leukemia cell line KG-1a. The effect of proliferation was detected by MTT assay after the KG-1a cell were stimulated for 24, 48 and 72 h with different concentrations of AZT; telomerase activity was detected with TRAP-PCR-ELISA assay; RT-PCR was used to detect telomerase hTERT mRNA expression. The results showed that the proliferation of KG-1a cells was inhibited in a time and concentration dependent manner after exposure to AZT for 24, 48 and 72 h; the KG-1a cells decreased in S phase and increased in G(2)/M phase with the increasing of the concentration of AZT; telomerase activity and hTERT-mRNA expression in the experimental groups decreased after treated with AZT, which was positively correlated with concentration of AZT. It is concluded that AZT inhibits KG-1a cell proliferation and induces apoptosis, which maybe related with its decreasing the telomerase activity and hTERT mRNA expression.

[Effects of Clostridium difficile toxin a on proliferation of K562 cells].

This study was aimed to investigate the effect of clostridium difficile toxin A (Tcd A) on proliferation of K562 cells and its mechanism. The proliferative activity of K562 cells exposed to Tcd A was tested by MTT assay; cell cycle distribution and mitochondrial membrane potential were analyzed by flow cytometry; the protein expression of cytochrome C and DNA fragmentation were observed by immunohistochemistry staining and agarose gel electrophoresis respectively. The results indicated that Tcd A inhibited proliferation of K562 cells in a time-and concentration-dependent manner. Cells were arrested at G(0)/G(1) phase. Peak of apoptosis appeared. The protein expression of cytochrome C increased as compared with control group (p < 0.05). Agarose gel electrophoresis of DNA from K562 treated with Tcd A revealed a "ladder" pattern. It is concluded that clostridium difficile toxin A can inhibit proliferation and induce apoptosis of K562 cells. The mechanism may be in relation to decrease of mitochondrial membrane potential and the release of cytochrome C from mitochondria matrix.

[Effect of Tangzhiping granule on blood lipids and free fatty acids in rats with insulin resistant diabetes].

OBJECTIVE: To investigate the effects of Tangzhiping Granule (TZPG) on blood lipids and free fatty acids (FFA) in rats with insulin resistant diabetes (IRD). METHODS: A blank control group consisted of randomly selected normal rats was set up. The remaining rats were established to IRD model by high-fat high-sugar diet feeding and streptozotocin injection. Then the 32 successfully modeled rats were randomized into the model group (treated by saline), the Tangmaikang group (treated with Tangmaikang Granule 1.35 g/kg), and the two TZPG groups treated with high dose (2.70 g/kg) and low dose TZPG (1.35 g/kg) respectively through intragastric infusion for 4 weeks. The body weight (BW), fasting blood glucose (FBG), insulin (INS), blood lipids including triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and FFA were detected, and the insulin sensitivity index (ISI) calculated. RESULTS: Compared with the blank control group, BW, FBG and INS increased while ISI decreased in the model group (P < 0.05 or P < 0.01). All the above-mentioned abnormal indices were improved in the three treated groups (Tangmaikang, high and low dose TZPG group), but the improvements in the high dose TZPG group were more significant than those in the other two groups (P < 0.05 or P < 0.01). Similar outcomes were also seen in blood lipids detection, in which TG, TC, LDL-C and FFA were higher and HDL-C were lower in model rats than those in blank controls, they were improved in the three treated groups (P < 0.05), and the best improvements were seen in the high dose TZPG group (P < 0.05). CONCLUSION: TZPG could reduce levels of BW, FBG, INS, TC, TG, LDL-C and FFA, and increase levels of ISI and HDL-C in rat model of insulin resistant type 2 diabetes, so as to improve the insulin resistance in them.