Hydrogen peroxide enhanced glow-type chemiluminescence of hydrazine hydrate modified carbon quantum dots-potassium persulfate system.

Most known chemiluminescence (CL) systems are flash-type that generate weak luminescence and decline quickly after dozens of seconds, while the glow-type CL systems have stable emission for an extended period to achieve accurate quantitation. In this work, a long-term CL system based on hydrazine-hydrate (N2H4·H2O) modified carbon quantum dots (N-CQDs) as a luminescent probe, with K2S2O8 and H2O2 as co-reactants, was proposed. The CL emission enhanced by H2O2 increased 18-fold more than that of N-CQDs and K2S2O8 direct reaction, and decayed by 5% of the maximum intensity over 700 s. In the reaction system, K2S2O8 and H2O2 co-reactants can promote each other to continuously generate corresponding radicals (•OH, O2•-, 1O2), which in turn trigger the CL emission of N-CQDs. This phenomenon was identified as the primary cause for the production of persistent CL. In addition, a stable and selective CL sensor based on the N-CQDs-K2S2O8-H2O2 CL enhancing system was developed for ascorbic acid quantitation in the linear range from 0.1 to 10.0 mM with a detection limit of 0.036 mM. The method has been applied to the analysis of tablet samples and holds potential in pharmaceutical analysis field.

An electrochemiluminescence resonance energy transfer biosensor based on CDs/PAMAM/rGO nanocomposites and Au@Ag2S nanoparticles for PML/RARα fusion gene detection.

In recent years, electrochemiluminescence resonance energy transfer (ECL-RET) with low background signal and high specificity has attracted much attention among researchers. Herein, we established a novel ECL-RET biosensor for PML/RARα fusion gene detection. In this ECL-RET system, carbon dots (CDs) with low toxicity and prominent electrochemical activity were used as donor and Au@Ag2S core-shell nanoparticles (Au@Ag2S NPs) were employed as ECL acceptor. The Au@Ag2S NPs possessed a wide ultraviolet-visible (UV-vis) absorption spectrum between 500 nm and 700 nm, which completely overlapped with the ECL spectrum of CDs. Furthermore, the CDs-decorated poly-amidoamine/reduced graphene oxide (CDs/PAMAM/rGO) nanocomposites were prepared to improve the ECL signals and served as a substrate to stably load capture probe deoxyribonucleic acid (DNA). Based on the ECL-RET biosensing strategy, the Au@Ag2S NPs-labeled assistant probes and target DNA could pair with capture probes to form the sandwich-type DNA structure and the distance between donor and accepter was closed, leading to quenching of the ECL signal of CDs. The ECL-RET biosensor represented eminent analytical performance for PML/RARα fusion gene detection with a wide linear relationship from 5 fM to 500 pM and a low detection limit of 0.72 fM, which provided a novel technical means and theoretical basis for detection and diagnosis of acute promyelocytic leukemia.

Hypoxia Upregulates NOTCH3 Signaling Pathway to Promote Endothelial-Mesenchymal Transition in Pulmonary Artery Endothelial Cells.

BACKGROUND: To investigate the effect of hypoxia on pulmonary artery endothelial cells and the role of NOTCH3 in endothelial-mesenchymal transition (EnMT) and to provide a research model for pulmonary disease and explain the pathogenesis of the pulmonary disease. METHODS: Pulmonary artery endothelial cells were divided into two groups and cultured in normoxic and hypoxic environments, respectively. QPCR, western blot, and immunofluorescence were used to detect endothelial cell-specific marker protein and mRNA expression in each group, and the ability of endothelial cells migration was evaluated by scratch and transwell experiment. RESULTS: The pulmonary artery endothelial cells in the normoxic group presented a typical pebble-like arrangement, and the endothelial cells in hypoxic culture showed a long spindle appearance. Hypoxia induced high expression of NOTCH3, Jagged-1, Hes1, c-Src, and CSL. Immunofluorescence showed that endothelial cells in hypoxic culture began to express the α-SMA, and the expression of vWF increased with hypoxia. Cell viability, scratch, and transwell results showed that endothelial cells in the hypoxic group were more capable of viability and migration than those in the normoxic group. The induction of EnMT by hypoxia can be inhibited by using notch3-specific inhibitor DAPT and Jagged-1. This study also found that miR-7-5p can regulate endothelial NOTCH3, indicating that miRNA is also involved in the process of endothelial-mesenchymal transformation. CONCLUSION: Hypoxia promotes the transformation of endothelial cells into mesenchymal cells by opening the NOTCH3 pathway, which lays the foundation for disease progression or clinical prognosis, and is of great significance in the treatment of diseases.

Combined effects of low-dose gambogic acid and NaI131 in drug-resistant non-small cell lung cancer cells.

Radioactive seed brachytherapy is a method for treating drug-resistant, late-stage non-small cell lung cancer (NSCLC). To elucidate the mechanism of low-dose gambogic acid (GA) and NaI131 in drug-resistant NSCLC cells, the human NSCLC A549 cell line and the drug-resistant A549/cisplatin (DDP) and A549/Taxol cell lines were treated with NaI131, low-dose GA or a combination of both in the present study; the control group of each cell line was treated with phosphate-buffered saline (PBS). Following treatment, cell proliferation, apoptosis and cell cycle analysis was performed. Apoptosis-related proteins, namely CDK1, cyclin B, mutant p53 (mtp53), heat shock protein 90 (HSP90), Bax and Bcl-2, and P-glycoprotein 1 (P-gp), which is known to confer resistance to chemotherapy, were detected using western blotting and immunofluorescence analysis. mRNA levels of p53 and HSP90 were measured using reverse transcription-quantitative PCR. Compared with the PBS control group, the A549, A549/DDP and A549/Taxol cells treated with NaI131, GA or a combination of the drugs exhibited G2/M arrest and increased percentages of total apoptotic cells, as well as significantly decreased protein levels of CDK1, cyclin B, mtp53, HSP90, Bcl-2 and P-gp, increased protein levels of Bax and decreased mRNA levels of p53 and HSP90. The changes in the combination group were the most evident and were significantly different from the other groups (P<0.001). In conclusion, low-dose GA may be a potential radionuclide sensitizer.

Clinical features of pulmonary embolism in patients with lung cancer: A meta-analysis.

BACKGROUND: Pulmonary embolism (PE) is correlated with increased mortality among patients with lung cancer (LC). The characteristics of patients with LC presenting with PE have not been fully established, and our meta-analysis aims to comprehensively investigate the clinical characteristics associated with PE in patients with LC to help physicians identify PE earlier in these patients. METHODS: Multiple databases were searched, including PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure and Wanfang. Odds ratios (ORs) and weighted mean differences (WMDs) with 95% confidence intervals (95% CIs) were used as effect measures for dichotomous and continuous variables, respectively. Moreover, Egger's test, Begg's test and a sensitivity analysis were performed to assess the publication bias and reliability of the articles. RESULTS: In total, 16 studies were included in our meta-analysis. The results indicated that history of chronic obstructive pulmonary disease (OR = 2.59, 95% CI: 1.09, 6.15; P = 0.03), adenocarcinoma (OR = 2.28, 95% CI: 1.88, 2.77; P < 0.01), advanced tumour stage (TNM III-IV vs. I-II, OR = 2.38, 95% CI: 1.99, 2.86; P < 0.01), history of central venous catheter (OR = 1.95, 95% CI: 1.36, 2.78; P < 0.01), history of chemotherapy (OR = 2.32, 95% CI: 1.80, 2.99, P < 0.01), high levels of D-dimer (WMD = 4.31, 95% CI: 2.53, 6.10; P < 0.01) and carcinoembryonic antigen (WMD = 10.30, 95% CI: 9.95, 10.64; P < 0.01) and a low level of partial pressure of oxygen (WMD = -25.97, 95% CI: -31.31, -20.62; P < 0.01) were clinical features of LC patients with PE compared to those without PE. CONCLUSIONS: These results reveal that LC patients with PE have specific clinical features, including but not limited to several cancer- and treatment-related factors, that may help their early identification.

[Therapeutic efficacy assessment of Chinese medicine on mild cognitive impairment].

OBJECTIVE: To systematically analyze the therapeutic efficacy and safety of Chinese medicine on aged patients with mild cognitive impairment (MCI). METHODS: The PubMed, EMbase, Cochrane Library, CNKI, VIP, Wanfang Database, and CBM database were retrieved by computer. On the basis of strictly assessing the quality of literatures, the evidence quality was assessed using GRADE Software. RESULTS: Totally 680 papers were primarily retrieved and analyses were conducted in the finally selected 22 RCT articles. Descriptive analyses were conduced due to different interventions in each study. The therapeutic efficacy was assessed as follows. (1) As to the conversion of MCI to Alzheimer's disease (AD), no case conversed to MCI in Jiawei Wuzi Yanzong Granule Group and Shenyin Oral Liquid Group. But there was no statistical difference when compared with that in the placebo group and the vitamin E group. Significant difference was shown between Tiantai No. 1 and the placebo. (2) As for the improvement of cognitive functions, relative therapeutic efficacies of Chinese herbs were different. (3) The improvement of the activities of daily life, serum SOD and MDA contents, and P amyloid concentration in MCI patients was different due to the application of different therapeutic drugs. CONCLUSION: Chinese herbs showed certain therapeutic efficacy in improving MCI. But clinical application could not be recommended due to poor qualities of literatures and evidence.

Identification of coastal water quality by statistical analysis methods in Daya Bay, South China Sea.

In this paper, cluster analysis (CA), principal component analysis (PCA) and the fuzzy logic approach were employed to evaluate the trophic status of water quality for 12 monitoring stations in Daya Bay in 2003. CA grouped the four seasons into four groups (winter, spring, summer and autumn) and the sampling sites into two groups (cluster DA: S1, S2, S4-S7, S9 and S12 and cluster DB: S3, S8, S10 and S11). PCA identified the temporal and spatial characteristics of trophic status in Daya Bay. Cluster DB, with higher concentrations of TP and DIN, is located in the western and northern parts of Daya Bay. Cluster DA, with the low Secchi, is located in the southern and eastern parts of Daya Bay. The fuzzy logic approach revealed more information about the temporal and spatial patterns of the trophic status of water quality. Chlorophyll a, TP and Secchi may be major factors for deteriorating water quality.

Identification of anthropogenic effects and seasonality on water quality in Daya Bay, South China Sea.

Thirteen water quality parameters from 12 monitoring stations were collected to study the effects caused by climate and anthropogenic activities on water quality in 2003 in Daya Bay, South China Sea. The data matrix has been built according to the results, which were analyzed by fuzzy c-mean cluster (FCM) and cluster analysis (CA). This analysis has identified anthropogenic effects and seasonal characters of water quality. The dry and wet seasonality have been demonstrated with FCM and CA. The precipitation and the Southeast Asian monsoons, northeasterly from October to the next April and southwesterly from May to September have also an important influence on water quality in Daya Bay. In the spatial pattern, two groups have been classified with FCM and CA. Cluster I consisted of the sites S3, S8, S10 and S11 in the west and north coastal parts of Daya Bay. Cluster I is mainly related to anthropogenic activities such as fish-farming. Cluster II consisted of the rest of the stations in the center, east and south parts of Daya Bay. Cluster II is mainly related to seawater input from South China Sea. Thus, fuzzy c-mean cluster and cluster analysis can be an important tool for the successful characterization of regional-scale water quality.

Studies on intrinsic ionization constants of Fe-Al-Mg hydrotalcite-like compounds.

The theoretical analysis of the intrinsic ionization constant (K(a2)(int)) of Fe-Al-Mg hydrotalcite-like compounds (HTlc) possessing permanent charges was first performed using the double extrapolation method proposed by James et al. The theoretical permanent charge density (sigma(p,T)) of the HTlc sample was calculated from the crystal structure of HTlc, and the influence of sigma(p,T) on the K(a2)(int) was also examined. From the experimental results, these conclusions can be obtained: the zero point of the charge (pH(ZPC)) of Fe-Al-Mg HTlc increases with decreased Fe3+ content and increases with increased Mg2+ in the HTlc. The pK(a2)(int) of Fe-Al-Mg HTlc also increases with decreased Fe3+ and increased Mg2+ content in the sample; furthermore, the pK(a2)(int) of Fe-Al-Mg HTlc increases with decreased sigma(p,T).