MicroRNA-411-3p motivates methotrexate's cellular uptake and cytotoxicity via targeting Yin-yang 1 in leukemia cells.

This study aimed to figure out how microRNA (miR)-411-3p's impacts on methotrexate (MTX)'s cellular uptake and cytotoxicity in acute lymphoblastic leukaemia (ALL) CEM-C1 cells by targeting Yin-yang 1 (YY1). miR-411-3p and YY1 were detected by RT-qPCR or Western blot. Intracellular MTX concentration was measured by enzyme-linked immunosorbent assay. Cell viability and apoptosis were evaluated by CCK-8, clonal formation assay, and flow cytometry. Verification of miR-411-3p and YY1's targeting link was manifested. It came out that miR-411-3p mimic or si-YY1 elevated intracellular MTX, MTX-induced cytotoxicity and apoptosis rate in CEM-C1. However, the inverse results were noticed in cells introduced with miR-411-3p inhibitor or oe-YY1. Meanwhile, it was found that cell relative luciferase activity was reduced after co-transfection of miR-411-3p mimic with YY1-WT, indicating that miR-411-3p targeted YY1. Elevation of YY1 could turn around elevating miR-411-3p's impacts on MTX's cellular uptake and cytotoxicity in CEM-C1 cells. These findings convey that miR-411-3p motivated MTX's cellular uptake and cytotoxic impacts via targeting YY1 in leukemia cells. This study is helpful for learning about the mechanisms underlying MTX responses in ALL patients.

Research progress of sophoridine's pharmacological activities and its molecular mechanism: an updated review.

Background: Sophoridine, the major active constituent of Sophora alopecuroides and its roots, is a bioactive alkaloid with a wide range of pharmacological effects, including antitumor, anti-inflammatory, antiviral, antibacterial, analgesic, cardioprotective, and immunoprotective activities. Sophora flavescens Aiton is a traditional Chinese medicine that is bitter and cold. Additionally, it also exhibits the effects of clearing heat, eliminating dampness, and expelling insects. Aims of the study: To summarize the pharmacological research and associated mechanisms of sophoridine, we compiled this review by combining a huge body of relevant literature. Materials and methods: The information related to this article was systematically collected from the scientific literature databases including PubMed, Google Scholar, Web of Science, Science Direct, Springer, China National Knowledge Infrastructure, published books, PhD and MS dissertations. Results: Its antitumor activity is particularly remarkable, as it can inhibit cancer cell proliferation, invasion, and metastasis while inducing cell cycle arrest and apoptosis. Additionally, sophoridine also holds therapeutic potential for myocardial ischemia, osteoporosis, arrhythmias, and neurological disorders, primarily through the suppression of related inflammatory factors and cell apoptosis. However, sophoridine has also exhibited adverse effects such as hepatotoxicity and neurotoxicity. The antidisease effect and mechanism of sophoridine are diverse, so it has high research value. Conclusion: As an important traditional Chinese medicine alkaloid, modern pharmacological studies have demonstrated that sophoridine has prominent bioactivities, especially on anti-tumor anti-inflammation activities, and cardiovascular system protection. These activities provide prospects for novel drug development for cancer and some chronic diseases. Nevertheless, the understanding of the multitarget network pharmacology, long-term in vivo toxicity, and clinical efficacy of sophoridine require further detailed research.

Dihydromyricetin Inhibits M1 Macrophage Polarization in Atherosclerosis by Modulating miR-9-Mediated SIRT1/NF-κB Signaling Pathway.

Dihydromyricetin (DMY), a natural flavonoid compound extracted from the stems and leaves of Ampelopsis grossedentata, has been found as a potential therapeutic chemical for treating atherosclerosis. This study explores the underlying mechanism of DMY repressing M1 macrophage polarization in atherosclerosis. We showed that DMY treatment markedly decreased M1 macrophage markers (e.g., Tnf-α and IL-1ß) and p65-positive macrophage numbers in the vessel wall of Apoe-deficient (Apoe-/-) mice. Overexpression of miR-9 or knockdown of SIRT1 in macrophages reversed the effect of DMY on M1 macrophage polarization. The data we presented in the study indicate that the miR-9-mediated SIRT1/NF-κB pathway plays a pivotal role in M1 macrophage polarization and is one of the molecular mechanisms underlying the anti-atherosclerosis effects of DMY. We provide new solid evidence that DMY may be explored as a potential therapeutic adjuvant for treating atherosclerosis.

Association of lncRNA PVT1 Gene Polymorphisms with the Risk of Essential Hypertension in Chinese Population.

Vascular dysfunction and hyperlipidemia are essential risk factors contributing to essential hypertension (EH). The plasmacytoma variant translocation 1 (PVT1) is involved in modulating angiogenesis in tumor tissues and plays an important role in fat differentiation in the progress of obesity. Therefore, we selected two tagSNPs of PVT1 (rs10956390 and rs80177647) to investigate whether they are contributing to the risk of hypertension in Chinese patients. In total, 524 adult patients with EH and 439 matched healthy controls were enrolled for two central of China. Results. PVT1 rs10956390 and rs80177647 polymorphisms were genotyped by using TaqMan assay. PVT1 rs10956390 TT genotype was associated with a decreased risk of EH (OR = 0.561, 95% CI = 0.372-0.846, P = 0.006), while rs80177647 TA genotype was associated with an increased risk (OR = 2.236, 95% CI = 1.515-3.301, P < 0.001). Rs10956390 T allele was associated with lower triglyceride levels in the plasma both from healthy and EH donors. What is more, there is an association between rs10956390 polymorphism and HDL-C level, as well as LDL-C. Conclusion. PVT1 rs10956390 and rs80177647 polymorphisms may contribute to the risk of EH in Chinese population by regulating blood lipid levels.

SOCS3 Gene Polymorphism and Hypertension Susceptibility in Chinese Population: A Two-Center Case-Control Study.

Endothelial inflammation and vascular damage are essential risk factors contributing to hypertension. Suppressor of cytokine signaling 3 (SOCS3) is involved in the regulation of multiple inflammatory pathways. A large number of studies have shown that the anti-inflammatory effect of SOCS3 in hypertension, obesity, and allergic reactions has brought more insights into the inhibition of inflammation. Therefore, we selected a tagSNP of SOCS3 (rs8064821) to investigate whether they are contributing to the risk of hypertension in the Chinese population. In total, 532 patients with hypertension and 569 healthy controls were enrolled for two central of China. SOCS3 rs8064821 C>A polymorphism was genotyped using TaqMan assay. SOCS3 rs8064821 CA genotype was associated with an increased risk of hypertension (OR = 1.821, 95%CI = 1.276-2.600, P = 0.001). Rs8064821 A allele was associated with higher SOCS3 mRNA level in PBMCs from healthy donors. SOCS3 rs8064821 C>A polymorphism may contribute to the risk of hypertension in the Chinese population by regulating the expression of SOCS3.

Dihydromyricetin Inhibits Tumor Growth and Epithelial-Mesenchymal Transition through regulating miR-455-3p in Cholangiocarcinoma.

Cholangiocarcinoma (CCA) leads to poor prognosis due to high aggressiveness and common chemoresistance. Dihydromyricetin (DMY), the main bioactive compound isolated from Ampelopsis grossedentata, exhibits broad anti-tumor effects. This study aimed to investigate the inhibitory effect of DMY on CCA tumor growth and epithelial-mesenchymal transition (EMT) and its underlying mechanism in CCA. DMY treatment significantly inhibited cell proliferation and EMT in CCA cell lines. The expression of ZEB1 and vimentin were down-regulated, while the level of E-cadherin was increased after DMY treatment. By analyzing the TCGA dataset, we found that miR-455 expression was significantly downregulated, while the level of ZEB1 was up-regulated in human CCA tumor tissues compared to normal samples. Mechanistic studies showed that ZEB1 was a direct target of miR-455-3p in CCA. Moreover, DMY treatment potently increased miR-455-3p expression and inhibited ZEB1 expression. Inhibition of miR-455-3p expression abolished DMY's inhibitory effects on tumor growth and EMT in both CCA cells and cell-engrafted nude mice. Finally, DMY significantly suppressed the expressions of p-PI3K and p-AKT, while silencing miR-455-3p remarkably abrogated the inhibitory effect. In conclusion, DMY suppresses tumor growth and EMT through regulating miR-455-3p in human cholangiocarcinoma, suggesting a potential option for CCA treatment.

Dihydromyricetin inhibits cell proliferation, migration, invasion and promotes apoptosis via regulating miR-21 in Human Cholangiocarcinoma Cells.

Dihydromyricetin, the most abundant natural flavonoid isolated from Ampelopsis grossedentata, exhibits broad anti-tumor effects. However, the effects of dihydromyricetin on cholangiocarcinoma remain unclear. This study examined the anti-tumor effects of dihydromyricetin in two human cholangiocarcinoma cell lines HCCC9810 and TFK-1, and the underlying mechanism was also investigated. Our study was the first to show that dihydromyricetin significantly inhibited cell proliferation, migration, invasion and promoted apoptosis in cholangiocarcinoma cells. By analyzing the TCGA dataset, we found that expression of miR-21, an oncogene and a potential target of anticancer drugs for cholangiocarcinoma, was upregulated in cholangiocarcinoma tissues compared to paired control tissues. Moreover, dihydromyricetin significantly reduced the expression of miR-21 in a dose-dependent manner. Overexpression of miR-21 remarkably abolished the inhibitory effects of dihydromyricetin on cell proliferation, migration, invasion and abrogated its effect of promoting cell apoptosis in both HCCC9810 and TFK-1 cells. Dihydromyricetin remarkably increased the expression of PTEN and decreased the expression of phosphorylated Akt, while overexpression of miR-21 abrogated the modulation of PTEN/ Akt pathway by dihydromyricetin. Taken together, our study demonstrates that dihydromyricetin inhibits cell proliferation, migration, invasion and promotes apoptosis in cholangiocarcinoma cells via regulating miR-21.

Dihydromyricetin increases endothelial nitric oxide production and inhibits atherosclerosis through microRNA-21 in apolipoprotein E-deficient mice.

Natural products were extracted from traditional Chinese herbal emerging as potential therapeutic drugs for treating cardiovascular diseases. This study examines the role and underlying mechanism of dihydromyricetin (DMY), a natural compound extracted from Ampelopsis grossedentata, in atherosclerosis. DMY treatment significantly inhibits atherosclerotic lesion formation, proinflammatory gene expression and the influx of lesional macrophages and CD4-positive T cells in the vessel wall and hepatic inflammation, whereas increases nitric oxide (NO) production and improves lipid metabolism in apolipoprotein E-deficient (Apoe-/- ) mice. Yet, those protective effects are abrogated by using NOS inhibitor L-NAME in Apoe-/- mice received DMY. Mechanistically, DMY decreases microRNA-21 (miR-21) and increases its target gene dimethylarginine dimethylaminohydrolase-1 (DDAH1) expression, an effect that reduces asymmetric aimethlarginine (ADMA) levels, and increases endothelial NO synthase (eNOS) phosphorylation and NO production in cultured HUVECs, vascular endothelium of atherosclerotic lesions and liver. In contrast, systemic delivery of miR-21 in Apoe-/- mice or miR-21 overexpression in cultured HUVECs abrogates those DMY-mediated protective effects. These data demonstrate that endothelial miR-21-inhibited DDAH1-ADMA-eNOS-NO pathway promotes the pathogenesis of atherosclerosis which can be rescued by DMY. Thus, DMY may represent a potential therapeutic adjuvant in atherosclerosis management.

[Effect of a Comprehensive Improvement Project on Water Quality in Urban Lakes: A Case Study of Water Quality Variation in Lihu Lake Over the Past 30 Years].

In order to improve water quality, many urban lakes in China have undergone environmental restoration since the introduction of China's tenth five-year plan. To understand the effectiveness of improvement projects on eutrophic urban lakes, we analyze the changes in water quality of Lihu Lake over the past 30 years, i.e., before and after comprehensive remediation. We use long-term monitoring data from TLLER and from two regional investigations undertaken in 2017. The results were as follows. ① Concentrations of total nitrogen (TN) and total phosphorus (TP), the permanganate index, and chlorophyll-a (Chl-a) in Lihu Lake all increased dramatically since the 1990s and reached the worst levels during the period from 1997 to 2003. After comprehensive improvement measures for the lake undertaken by the local government in 2003, the water quality improved remarkably year by year, but reduced slightly in the past two years assessed here. There was no obvious improvement in water transparency when comparing data from before to after the remediation. ② Before the improvement measures, the water quality fluctuated greatly with season, however, water quality sampled during the winter post remediation was significantly better than during the summer. ③ Spatially, the water quality in the western region of Lihu Lake was significantly better than of that in the eastern region. When comparing government measures in different eutrophic urban lakes, we found that engineering management measures can improve the water quality of urban lakes over a relatively short time period. However, after the water quality has been improved, it is necessary to restore the macrophyte-dominated ecosystem, which should be supplemented by ecological restoration based on biological regulation. By improving species diversity, the aquatic ecosystem can be successfully transformed from being phytoplankton-dominated to macrophyte-dominated, thereby enabling the service functions of a lake ecosystem to be truly restored.

Comprehensive expression profiles and bioinformatics analysis reveal special circular RNA expression and potential predictability in the peripheral blood of humans with idiopathic membranous nephropathy.

The etiology of idiopathic membranous nephropathy (IMN) is considered to be closely associated with immunoregulation and genetic factors. Circular RNAs (circRNAs) have been found to regulate gene expression in various organisms, and to play an important role in multiple physiological and pathological processes, which may be involved in the pathogenesis of IMN. The purpose of the present study was to investigate the potential relationship between circRNAs in peripheral blood and disease. The diagnoses of IMN were confirmed using electron microscopy and immunofluorescence. Total RNA was isolated and microarray analysis was used to detect the expression levels of circRNAs in the peripheral blood of patients with IMN and in normal subjects. Selected genes from the microarray were selected and verified by reverse transcription­quantitative (RT­q)PCR. Bioinformatics tools were applied for further functional evaluation, and the potential disease predictability of circRNAs was determined using receiver­operating characteristic (ROC) curves. The results showed that a total of 955 differentially expressed circRNAs were found in blood samples, 645 of which were upregulated and 310 which were downregulated. In total, five candidate circRNAs were validated using RT­qPCR analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses identified numerous types of target genes and their corresponding microRNAs (miRNAs). The miRNAs identified were involved in biological processes and enriched in multiple important pathways, including the mitogen­activated protein kinase, transforming growth factor­ß and Ras signaling pathways. The levels of circ_101319 were significantly higher (P<0.001) and exhibited promising diagnostic value in patients with IMN (area under ROC =0.89). The co­expression network constructed for circ_101319 indicated that it may be associated with membranous nephropathy­related pathways by mediating miRNAs. In conclusion, the present study revealed the expression and functional profile of differentially expressed circRNAs in the peripheral blood of patients with IMN, and provided new perspectives to predict and elucidate the development of IMN.

[Seasonal Difference in Water Quality Between Lake and Inflow/Outflow Rivers of Lake Taihu, China].

The seasonal and spatial variation of external nutrient loading from rivers and their impact on lake water quality were analyzed in Lake Taihu, China, using the monthly monitoring data from 16 major inflow/outflow rivers and 32 observation sites in the lake. The results showed:① The average monthly values of total nitrogen (TN), dissolved total nitrogen (DTN), total phosphorus (TP), and dissolved total phosphorus (DTP) in rivers were all higher than the corresponding areas in the lake. Significant positive correlations were found between nutrient concentrations in the inflow rivers and the corresponding areas in the lake, indicating the pronounced impact of external loading on lake water. ② Remarkable seasonal variations of nutrient concentration were found both in the rivers and in the lake. The highest TN and TP concentrations in inflow rivers were 4.82 mg·L-1 (March) and 0.218 mg·L-1 (December), while the highest TN and TP concentrations in the lake were 4.13 mg·L-1 and 0.255 mg·L-1 in July. ③ Extreme rainfall events could decrease the nutrient concentration in the rivers in the short-term, but finally would increase the external loading of nutrients, and indicated disadvantages for the restoration of Lake Taihu. Our study concluded that inflow pollution showed an obvious "shaping effect" on the seasonal and spatial distribution of water quality indicators in large and shallow lakes. Additionally, the self-purification ability of lakes, wind-induced accumulation and migration of algae, as well as the sediment resuspension under the prevailing winds in different seasons, all have vital effects on nutrient concentrations and their spatial-temporal variations.

Dihydromyricetin Attenuates TNF-α-Induced Endothelial Dysfunction through miR-21-Mediated DDAH1/ADMA/NO Signal Pathway.

Accumulating studies demonstrate that dihydromyricetin (DMY), a compound extracted from Chinese traditional herb, Ampelopsis grossedentata, attenuates atherosclerotic process by improvement of endothelial dysfunction. However, the underlying mechanism remains poorly understood. Thus, the aim of this study is to investigate the potential mechanism behind the attenuating effects of DMY on tumor necrosis factor alpha- (TNF-α-) induced endothelial dysfunction. In response to TNF-α, microRNA-21 (miR-21) expression was significantly increased in human umbilical vein endothelial cells (HUVECs), in line with impaired endothelial dysfunction as evidenced by decreased tube formation and migration, endothelial nitric oxide synthase (eNOS) (ser1177) phosphorylation, dimethylarginine dimethylaminohydrolases 1 (DDAH1) expression and metabolic activity, and nitric oxide (NO) concentration as well as increased asymmetric dimethylarginine (ADMA) levels. In contrast, DMY or blockade of miR-21 expression ameliorated endothelial dysfunction in HUVECs treated with TNF-α through downregulation of miR-21 expression, whereas these effects were abolished by overexpression of miR-21. In addition, using a nonspecific NOS inhibitor, L-NAME, also abrogated the attenuating effects of DMY on endothelial dysfunction. Taken together, these data demonstrated that miR-21-mediated DDAH1/ADMA/NO signal pathway plays an important role in TNF-α-induced endothelial dysfunction, and DMY attenuated endothelial dysfunction induced by TNF-α in a miR-21-dependent manner.

Soil geochemistry and digestive solubilization control mercury bioaccumulation in the earthworm Pheretima guillemi.

Mercury presents a potential risk to soil organisms, yet our understanding of mercury bioaccumulation in soil dwelling organisms is limited. The influence of soil geochemistry and digestive processes on both methylmercury (MeHg) and total mercury (THg) bioavailability to earthworms (Pheretima guillemi) was evaluated in this study. Earthworms were exposed to six mercury-contaminated soils with geochemically contrasting properties for 36 days, and digestive fluid was concurrently collected to solubilize soil-associated mercury. Bioaccumulation factors were 7.5-31.0 and 0.2-0.6 for MeHg and THg, respectively, and MeHg accounted for 17-58% of THg in earthworm. THg and MeHg measured in soils and earthworms were negatively associated with soil total organic carbon (TOC). Earthworm THg and MeHg also increased with increasing soil pH. The proportion of MeHg and THg released into the digestive fluid (digestive solubilizable mercury, DSM) was 8.3-18.1% and 0.4-1.3%, respectively. The greater solubilization of MeHg by digestive fluid than CaCl2, together with a biokinetic model-based estimate of dietary MeHg uptake, indicated the importance of soil ingestion for MeHg bioaccumulation in earthworms.

[Measurement of dissolved organic nitrogen with nanofiltration pretreatment and its distribution characteristics in landscape water].

In this study, we present a nanofiltration (NF90, NF270) pretreatment to increase the precision of dissolved organic nitrogen (DON) measurements in water samples. The variations of DON measurements with and without NF pretreatment were investigated. And the effects on the removal of dissolved inorganic nitrogen (DIN) by NF90 and NF270 were compared. As shown in the results, the average removal rates reached 30.7%, 55.9% of NH4(+)-N, 50.0%, 73.1% of NO3(-) -N and 42.9%, 72.0% of NO2(-)-N for NF90 and NF270 pretreatment, respectively. NF270 was obviously more effective to remove the DIN species. Concentrations of DON measured using traditional methods varied from 0.09 to 0.46 mg x L(-1), with negative concentration (-0.08 mg x L(-1)) at site 2 and the DIN/TDN ratio ranged from 85.3% to 105%; while the concentrations of DON measurements varied from 0.03 to 0.58 mg x L(-1), and the DIN/TDN ratio ranged from 76.1% to 90.6% for NF90 pretreatment and varied from 0.10 to 0.59 mg x L(-1), and the DIN/TDN ratio ranged from 47.5% to 84.5% for NF270 pretreatment. The results indicated that nanofiltration pretreatment could effectively remove the DIN species, decrease the standard deviation of DON measurements and increase the precision of DON measurements. The distribution of DON in water samples of Beijing Olympic Forest Park was investigated. The results showed that there was seasonal variation in the concentrations of DON in landscape water from the Olympic Forest Park. And there was significant difference between the north and south part. The DON concentrations were less than 0.2 mg x L(-1) in November, March and May and higher in July in the north part, while the DON concentrations were lower in May and higher in November and March in the south part, ranging from 0.40-0.65 mg x L(-1).

Oxidative DNA damage induced by a Copper(II)-1,10-phenanthroline-L-serine complex in the presence of rutin.

The capacity of the ternary complex copper(II)-1,10-phenanthroline-L-serine ([Cu-Phen-Ser]) to induce double-strand scission of DNA was explored by agarose-gel electrophoresis. It was found that the complex exhibited remarkable activity to damage DNA in the presence of rutin. Analysis of the UV and fluorescence spectra clearly demonstrated that the complex was bound to DNA by intercalation. Further, the occurrence of 8-hydroxydeoxyguanosine (8-OHdG), a biomarker of oxidative DNA damage, after the treatment of DNA by the complex in presence of rutin was evidenced by an electrochemical method. Finally, the mechanism of oxidative damage to double-stranded DNA by the [Cu-Phen-Ser] complex in the presence of rutin was discussed.

Copper (II) complex of 1,10-phenanthroline and L-tyrosine with DNA oxidative cleavage activity in the gallic acid.

Copper (II) complex of formulation [Cu-Phen-Tyr](H(2)O)](ClO(4)) (Phen = 1,10-phenanthroline, L: -Tyr = L: -tyrosine), has been prepared, and their induced DNA oxidative cleavage activity studied. The complex binds to DNA by intercalation, as deduced from the absorption and fluorescence spectral data. Scatchard plots constructed from the absorption titration data gave binding constant 2.44 × 10(4) M(-1) of base pairs. Extensive hypochromism, broadening, and red shifts in the absorption spectra were observed. Upon binding to DNA, the fluorescence from the DNA--ethidium bromide system was efficiently quenched by the copper (II) complex. Stern--Volmer quenching constant 0.61 × 10(3) M(-1) obtained from the linear quenching plots. [Cu-Phen-Tyr] complex efficiently cleave the supercoiled DNA to its nicked circular form with gallic acid as biological reductant at appropriate complex concentration. The gallic acid as reductant could observably improve copper (II) complex to DNA damage. The pseudo-Michaelis-Menten kinetic parameters (k(cat), K(M)) were calculated to be 1.32 h(-1) and 5.46 × 10(-5) M for [Cu-Phen-Tyr] complex. Mechanistic studies reveal the involvement of superoxide anions and hydroxyl radical (HO(·)) as the reactive species under an aerobic medium.

Neferine increases STI571 chemosensitivity via inhibition of P-gp expression in STI571-resistant K562 cells.

We investigated the effects of neferine (Nef) on STI571 sensitivity and the possible mechanism in STI571-resistant K562/G01 cells. We observed cell proliferation by the modified MTT (methyl thiazolyl tetrazolium) assay. We determined the intracellular concentration of STI571 in K562/G01 cells by high-performance liquid chromatography (HPLC), the expression of P-glycoprotein (P-gp) by Western blotting, and the expression of MDR-1 mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR). We observed that drug resistance to STI571 for K562/G01 cells was 43.99-fold higher than that for K562 cells. We also observed that a low concentration of Nef (<8 µM) and verapamil hydrochloride (VRP) (<10 µM) showed no direct cytotoxicity but significantly reduced the 50% cell growth inhibitory concentration (IC(50)) values of STI571 in K562/G01 cells. The reverse multiples for 8 µM Nef and 10 µM VRP were approximately two-fold. Both Nef (8 µM) and VRP (10 µM) decreased MDR-1 mRNA and P-gp protein expression and increased intracellular STI57I concentrations significantly in K562/G01 cells. Nef is a candidate chemical that can increase STI571 chemosensitivity in STI571-resistant K562 cells by inhibition of P-gp expression and increasing intracellular STI571 accumulation.

Amperometric sensors based on Ni/Al and Co/Al layered double hydroxides modified electrode and their application for hydrogen peroxide detection.

Two different hydrogen peroxide sensors were constructed with Ni/Al and Co/Al layered double hydroxides (LDHs) modified glassy carbon electrodes (GCE). Ni (Co)/Al-LDHs were synthesized by electrochemical method and were characterized by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The advantages and shortcoming of the two hydrogen peroxide sensors were described in detail. Compared to Co/Al-LDHs modified electrode, sensors fabricated by Ni/Al-LDHs showed quicker heterogeneous electron transfer rate constants (k(s)), lower detection and better reproducibility. But Co/Al-LDHs modified electrode held the advantages of wider linear range and higher sensitivity. Further more, the different catalytic redox mechanisms of hydrogen peroxide on the Ni/Al/GCE and Co/Al/GCE were firstly comparatively explored.

The interaction of taurine-salicylaldehyde Schiff base copper(II) complex with DNA and the determination of DNA using the complex as a fluorescence probe.

The interaction of taurine-salicylaldehyde Schiff base copper(II) (Cu(TSSB)2(2+)) complex with DNA was explored by using UV-vis, fluorescence spectrophotometry, and voltammetry. In pH 7.4 Tris-HCl buffer solution, the binding constant of the Cu(TSSB)2(2+) complex interaction with DNA was 3.49 x 10(4) L mol(-1). Moreover, due to the fluorescence enhancing of Cu(TSSB)2(2+) complex in the presence of DNA, a method for determination of DNA with Cu(TSSB)2(2+) complex as a fluorescence probe was developed. The fluorescence spectra indicated that the maximum excitation and emission wavelength were 389 nm and 512 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range of 0.03-9.03 microg mL(-1) for calf thymus DNA (CT-DNA), 0.10-36 microg mL(-1) for yeast DNA and 0.01-10.01 microg mL(-1) for salmon DNA (SM-DNA), respectively. The corresponding detection limits are 7 ng mL(-1) for CT-DNA, 3 ng mL(-1) for yeast DNA and 3 ng mL(-1) for SM-DNA. Using this method, DNA in synthetic samples was determined with satisfactory results.

A L-cysteine sensor based on Pt nanoparticles/poly(o-aminophenol) film on glassy carbon electrode.

Platinum nanoparticles (nano-Pt) and poly(o-aminophenol) (POAP) were fabricated onto the glassy carbon electrode(GCE) to form the nano-Pt/POAP/GCE for the electrochemical determination of L-cysteine. The POAP film was obtained through electrochemical polymerization of o-aminophenol on GCE. The nano-Pt was electrochemically deposited onto the surface of the activated POAP/GCE The resultant nano-Pt/POAP/GCE was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and showed excellent electrochemical response to L-cysteine at low oxidative potential in Britton-Robinson (BR) buffer solution (pH=3.0), with good stability and sensitivity, and featured with a low detection limit (0.08 microM, signal/noise=3) and wide linear range (0.4 microM-6.3mM).The mechanism for the electrochemical oxidation of L-cysteine on the nano-Pt/POAP/GCE was also investigated.