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1.
J Cell Physiol ; 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32020591

RESUMO

Long noncoding RNAs (lncRNAs) have been reported to dysregulate and involve in the pathology of hepatocellular carcinoma (HCC). Nonetheless, the functional role of lncRNA T cell leukemia/lymphoma 6 (TCL6) and its underlying mechanism in HCC remain unclear. Herein, we analyzed the expression of TCL6 and elucidated its mechanistic involvement in HCC. Bioinformatics analyses indicated TCL6 was evidently downregulated in HCC tissues compared with normal controls. TCL6 was downregulated while microRNA-106a-5p (miR-106a-5p) was upregulated in HCC cell lines. Moreover, knockdown or overexpression of TCL6 significantly raised or diminished the expression level of miR-106a-5p in HCC cells, similar to the effect of miR-106a-5p on TCL6 expression. Functionally, TCL6 inhibited the proliferative, migratory, and invasive potentials of HCC cells as analyzed by cell counting kit-8, scratch wound healing, and transwell assays, respectively. Conversely, miR-106a-5p exerted an opposite effect on the proliferative, migratory, and invasive potentials of HCC. RNA immune precipitation and luciferase reporter assays revealed TCL6 directly bound to miR-106a-5p and luciferase reporter assay verified phosphatase and tensin homolog (PTEN) was a target gene of miR-106a-5p. Mechanistically, TCL6 knockdown evidently reduced PTEN expression at both messenger RNA and protein levels, and miR-106a-5p inhibitor partially rescued this reduction effect in HCC cells. Additionally, western blot assays demonstrated miR-106a-5p downregulation or TCL6 overexpression promoted the protein level of PTEN, and suppressed the phosphorylation level of AKT, the protein level of phosphatidylinositol 3-kinase (PI3K). Collectively, these results revealed TCL6 as a tumor-suppressive lncRNA regulates PI3K/AKT signaling pathway via directly binding to miR-106a-5p in HCC. This mechanism provides a theoretical basis for HCC pathogenesis and a potential therapeutic strategy for HCC treatment.

2.
Dig Dis Sci ; 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31974911

RESUMO

BACKGROUND AND AIMS: Acute pancreatitis (AP) is a severe pancreatic disorder that remains associated with high mortality due to a lack of effective drugs and management strategies. This study aimed to investigate the molecular pathogenic mechanisms of AP involving p53 and endoplasmic reticulum (ER) stress pathways. METHODS: Expression of PRSS1 and p53 in human AP tissues was detected by immunohistochemistry and Western blotting. AP was induced with caerulein in humanized PRSS1 transgenic mice, and its severity was verified by histological imaging, evaluation of edema, serum amylase, and trypsin activity assays. A transferase-mediated d-UTP nick end-labeling assay was performed to evaluate acinar cell apoptosis associated with AP. The expression of ER stress genes was assessed by quantitative RT-PCR (qRT-PCR) and Western blotting. RESULTS: PRSS1 and p53 were highly expressed in human AP tissues. Expression of human PRSS1 in caerulein-treated mice induced significant acinar cell apoptosis and AP progression. P53 knockout significantly suppressed AP progression in humanized PRSS1 transgenic mice. The ER stress pathway was activated by PRSS1 and mediated the progression of AP in mouse pancreatic tissues. Application of a p53 inhibitor effectively ameliorated caerulein-induced AP in PRSS1 transgenic mice, while a p53 activator promoted the progression of AP. CONCLUSION: P53, which was activated by the ER stress pathway, promoted the progression of AP in mice expressing PRSS1 by inducing acinar cell apoptosis.

3.
Exp Cell Res ; : 111863, 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-31987787

RESUMO

BACKGROUND: Gallbladder carcinoma (GBC) is a common malignant tumor of the biliary system, but the current treatment of GBC is unsatisfactory. Therefore, new treatment targets and strategies are urgently needed. METHODS: The expression of HASPIN in GBC was detected by immunohistochemical staining. HASPIN knockdown cell model was constructed by lentivirus infection, and the infection efficiency of lentivirus and knockdown efficiency of shHASPIN were verified by fluorescence immunoassay, qRT-PCR and Western blot. The effects of HASPIN knockdown on cell proliferation, clone-formation ability and apoptosis were determined by MTT, clone formation assay, flow cytometry and Human Apoptosis Antibody Array in vitro. Besides, the effect of HASPIN knockdown on the growth of GBC solid tumors was demonstrated in vivo. RESULTS: The expression of HASPIN in GBC was up-regulated and positively correlated with the pathological grade of GBC. ShHASPIN significantly down-regulated the mRNA and protein levels of HASPIN, suggesting that HASPIN knockdown cell model was successfully constructed in vitro. After HASPIN knockdown, the proliferation and clone-formation ability of GBC cells were observably inhibited, the apoptotic levels were markedly increased, and the expression of Caspase 3, IGFBP-5, p21 and sTNF-R1 related to apoptotic pathway was up-regulated. Furthermore, HASPIN knockdown inhibited the growth of GBC in vivo. CONCLUSION: HASPIN was up-regulated in GBC and played an important role in promoting the progress of GBC.

4.
Mikrochim Acta ; 187(2): 137, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31953688

RESUMO

Fluorescent nanoparticles were prepared by encapsulating carbon dots (CDs) within silica spheres and then modifying these spheres with amino groups (CD@SiO2-NH2). On the basis of the silver mirror reaction, Ag+ assembled on the surface of CD@SiO2-NH2 is reduced to silver nanoparticles (AgNPs) by formaldehyde. The in-situ grown AgNPs cause a visually distinguishable fluorescence enhancement. This metal-enhanced effect was investigated by transmission electron microscopy and spectroscopic characterization, and the relevant conditions were optimized. CD@SiO2-NH2-Ag+ fluorescent probes were loaded onto nano-sponge pieces for the analysis of formaldehyde gas. The blue fluorescence emission (peaking at 466 nm) in response to formaldehyde is greatly enhanced (up to 5.2 times) over other species. There is a linear relationship between the fluorescence enhancement and formaldehyde gas concentration in the range of 10 ppb to 1 ppm, and the detection limit is 3 ppb. The fluorimetric assay needs 30 min for the reaction, and the fluorescent nano-sponge pieces are disposable. Graphical abstractSchematic representation of the metal-enhanced fluorescence (MEF) induced by in-situ grown silver nanoparticles on silica-encapsulated carbon dots, and its application in formaldehyde gas assays.

5.
Anal Chem ; 92(1): 1236-1244, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31779312

RESUMO

In recent years, inorganic biomimetic nanozymes that mimic the activity of natural biological enzymes have attracted extensive research interest, and some mimic enzymes have been successfully applied in the fields of biosensing, catalysis, and oncotherapy. Herein, we report the preparation and mechanism study of a novel nanocomposite, Cu2+-modified hexagonal boron nitride nanosheets-supported subnanometer gold nanoparticles (Au NPs/Cu2+-BNNS). Interestingly, our investigation reveals that Cu2+-BNNS exhibits strong peroxidase mimetic nanoenzyme activity, while Au NPs/Cu2+-BNNS exhibits excellent oxidase-like activity, that is, it can catalyze the oxidation reaction of the substrate in the absence of an oxidant such as H2O2. For example, Au NPs/Cu2+-BNNS can efficiently and selectively oxidize 3,3',5,5'-tetramethylbenzidine (TMB) and 3,3'-dimethylbiphenyl-4,4'-diamine (OT) coloration without the presence of horseradish peroxidase (HRP) and H2O2. It is worthy to note that AuNPs/Cu2+-BNNS-induced TMB coloration only takes 4 min to reach the platform, while the conventional HRP-H2O2 system takes more than 30 min to reach the platform. Further mechanism study shows that the zeta potential, oxidation potential, and steric hindrance of the oxidative chromogenic substrate determine the selectivity of oxidation coloration, while the oxidase-like properties of Au NPs/Cu2+-BNNS are derived from reactive oxygen species generated by the adsorbed oxygen, and Cu2+ ion can synergistically promote the oxidation process. Compared with conventional biological enzymes, Au NPs/Cu2+-BNNS has the advantages of being HRP free and H2O2 free, having high efficiency, low cost, and good stability, and is successfully demonstrated for the detection of carcinoembryonic antigen (a universal cancer biomarker) and H2S (the third gaseous signal molecule).

6.
Analyst ; 145(2): 460-465, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31781712

RESUMO

CD44 is a promising biomarker in the diagnosis and prognosis of malignancies. The serum CD44 level is closely related to disease progression and metastasis of malignancies. It is of great clinical significance for the detection of serum soluble CD44. In this study, a facile, label-free aptamer based electrochemical impedance sensor for serum CD44 has been proposed. The aptamer showing high affinity to CD44 was immobilized on the gold electrodes through Au-S interaction. The interaction between target CD44 and the immobilized aptamer will cause a complex structure change of the aptamer, which makes the diffusion of [Fe(CN)6]3-/4- toward the electrode surface easy, thus resulting in the decrease of the impedance of the system. The decreased degree of the impedance had a good linear relationship with the logarithm of the CD44 concentration in the range of 0.1-1000 ng mL-1 with a detection limit of 0.087 ng mL-1 (S/N = 3). The developed biosensor has been applied to detect CD44 in serum samples with satisfactory results.

7.
Food Chem ; 307: 125528, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31648181

RESUMO

Simple, rapid, convenient, and economical surface enhanced Raman scattering (SERS) substrate is developed for on-site evaluation of Aflatoxin B1 (AFB1) in food matrix using handheld Raman Spectrometer. Self-assembly of gold nanobipyramids (Au NBPs) into the nanoholes of anodic aluminum oxide (AAO) template/pattern using 'drop-dry' approach provides a reliable pathway for the rapid fabrication of highly active and uniform SERS substrate. It shows enhanced and reproducible SERS signals towards the probe molecule, 4-aminothiophenol (4-ATP) with a relative standard deviation (RSD) of less than 10% and an average enhancement factor (EF) of 1 × 108. For practical application, the proposed method is demonstrated for the detection of aflatoxin B1 (AFB1) in peanut extracts. The results show that the AFB1 in peanut extracts can be identified within 1 min, with a limit of detection of 0.5 µg/L. Compared with conventional ELISA based AFB1 analysis, our method is much more efficient (1 min versus >30 min).


Assuntos
Aflatoxina B1/análise , Arachis/química , Nanoestruturas/química , Extratos Vegetais/química , Análise Espectral Raman/métodos , Óxido de Alumínio/química , Arachis/metabolismo , Ouro/química , Limite de Detecção
8.
Biosens Bioelectron ; 147: 111789, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31655383

RESUMO

A novel electrochemiluminescence (ECL) biosensor was developed for high sensitive and selective detection of miRNA-21 based on the efficient and specific toehold-mediated strand displacement (TMSD) amplification with Ru(phen)32+ loaded DNA nanoclews (NCs-Ru(phen)32+) as signal tags. The stable DNA nanoclews, synthesized by a simple rolling circle amplification reaction, were employed to load with Ru(phen)32+ efficiently as ECL signal tags to amplify the signals. As for TMSD, the substrate strand (Sub) was initially hybridized with P1 and P2 to form DNA duplex structures with a toehold 1. miRNA-21 could hybridize with the toehold 1 and trigger the TMSD amplification with the help of assist strand, releasing lots of P1 stands from DNA duplex structures. The TMSD technique realized the converting and amplification of the single miRNA-21 input to lots of output DNA (namely P1) with good selectivity, simultaneously. Output P1 were designed to expand the stem-locked region of HP, which were immobilized on the Au electrodes firstly. Subsequently, the opened HP could hybridize with the Ru(phen)32+, capturing the ECL signal tags closed to the sensing surface. The ECL intensity of the system had a linear relationship with the logarithm of the miRNA-21 concentration in the range of 1.0 fM to 100 pM with a limit of detection of 0.65 fM. The strategy was further applied to detect miRNA-21 in complex samples, and the result was consistent with the qRT-PCR.

9.
Talanta ; 208: 120478, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816702

RESUMO

As an emerging field of study, microplastics have drawn tremendous attention, but until now little is known about their fate and impacts in the environment. A critical bottleneck is lack of reliable techniques to identify and quantify microplastics in complex media. Here we present a simple, rapid, and effective method for identification and quantification of micro/nanoplastics (MNPs) based on thermal fragmentation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with polystyrene (PS) particles as a model MNP. The PS MNPs are identified by fingerprint peaks in both low-mass (m/z 90, 104, 128, 130, and 312-318) and high-mass regions (repeated peaks with Δm/z 104 in the m/z range 350-5000), and the quantification is carried out with m/z 315.3. The different ionization behaviors enable the differentiation of MNPs with different molecular weights. Notably, we find that a simple thermal pretreatment at 380 °C can facilitate the fragmentation of PS and significantly enhances the intensities of fingerprint peaks in low-mass regions, yielding a detection limit of 25 ng for PS MNPs. The applicability of the method in different sample matrices and for other types of MNPs such as polyethylene terephthalate (PET) is also validated. Considering the current shortcomings in MNP analysis, this work provides a powerful tool to advance the MNPs research.

10.
Oncologist ; 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784489

RESUMO

BACKGROUND: The objective of this study was to develop and validate a nomogram to predict 1-year overall survival (OS) and 2-year OS in patients with high-grade digestive neuroendocrine neoplasms (NENs) as well as to guide selection of subgroups that could benefit from systemic chemotherapy. SUBJECTS, MATERIALS, AND METHODS: We performed a retrospective analysis of 223 patients with NENs of the gut and hepato-biliary-pancreatic system from four centers included in the development cohort. The nomogram was externally validated in a cohort of 90 patients from another one. RESULTS: The final model included lactate dehydrogenase, performance status, stage, Ki67, and site of primary tumor, all of which had a significant effect on OS. The uncorrected C-index was 0.761 for OS, and the bias-corrected C-index was 0.744. Predictions correlated well with observed 1-year and 2-year outcomes (judged by eye). The area under the time-dependent receiver operating characteristic curve at 12 months and 24 months was 0.876 and 0.838, respectively. The nomogram performed well in terms of both discrimination and calibration when applied to the validation cohort, and OS was significantly different between the two groups classified by nomogram score (log-rank p < .001). CONCLUSION: The validated nomogram provided useful prediction of OS, which can be offered for clinicians to improve their abilities to assess patient prognosis, to create clinical risk groups for informing treatment or for patient stratification by disease severity in clinical trials. IMPLICATIONS FOR PRACTICE: The high-grade neuroendocrine neoplasms of the digestive system are rare malignancies with great heterogeneity. An overall survival nomogram was developed and externally validated in this study. Two subgroups were classified by the nomogram score, and platinum-based chemotherapy may not bring clinical benefit for the low-risk patients.

11.
Strahlenther Onkol ; 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31828392

RESUMO

PURPOSE: Considering the effects of P53 binding protein 1 (53BP1) expression and T lymphocyte infiltration density on tumor radiosensitivity, we investigated the relation of 53BP1 expression and immunoscore based on T lymphocyte infiltration density with the efficacy of neoadjuvant chemoradiotherapy (CRT) for rectal cancer. METHODS: Fifty-five patients with rectal cancer receiving neoadjuvant CRT followed by surgery were enrolled. The 53BP1 expression level and the density of CD3+, CD8+, and CD45RO+ T lymphocytes in the tumor tissues were examined by immunohistochemistry, and the relation of these findings to the rates of tumor regression, disease-free survival (DFS), and overall survival (OS) was analyzed. RESULTS: The levels of 53BP1 and the CD3/CD8 immunoscore were closely correlated with the response to CRT (p < 0.05), with an area under the receiver operating characteristic curve for CRT efficacy prediction of 0.626 and 0.717, respectively. Further survival analysis revealed that high 53BP1 expression effectively prolonged 2­year DFS compared with low 53BP1 expression (87.5% [95%CI 77.3-97.7] vs. 53.3% [95%CI 28.1-78.6]; p < 0.05), while the effect of immunoscore on survival was restricted by the expression status of 53BP1. Cox multivariate analysis confirmed 53BP1 as an independent prognostic factor in DFS. CONCLUSION: The pretreatment levels of 53BP1 and the immunoscore based on CD3+/CD8+ T cell infiltration density in tumor tissues are effective predictors for the CRT response, and 53BP1 has a more pronounced impact on prognosis.

12.
Anal Chem ; 91(24): 15915-15921, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31755262

RESUMO

The instability and insolubility of perovskite quantum dots in aqueous solution prohibit applications in polar solvents. As a highly toxic gas pollutant and also an endogenous gaseous signaling molecule existing in a variety of physiological processes, hydrogen sulfide (H2S), with high selectivity and high specificity, detection is of great significance. In this study, a simple device has been designed to separate H2S from aqueous solution and CsPbBr3 quantum dots (CsPbBr3 QDs) have been used as the detection probe to develop a novel fluorescent sensor for rapid H2S detection. The addition of hydrogen sulfide to the phosphoric acid solution results in the escape of H2S from the aqueous sample and hence it passing into the n-hexane solution containing CsPbBr3 QDs, resulting in the quenching of the fluorescence of CsPbBr3 QDs. The fluorescence intensity of the system has a linear relationship with the concentration of H2S in the range of 0-100 µM with the detection limit of 0.18 µM. The proposed system has been applied to detection of H2S in rat brain microdialysate with satisfying results. The potential mechanism regarding the quenching of fluorescence from CsPbBr3 QDs by H2S has been studied as well.

13.
Chem Commun (Camb) ; 55(100): 15065-15068, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31777871

RESUMO

Graphitic carbon nitride (g-CN) nanosheets (CNNs) with an ultra-high quantum yield (80.1%) ultraviolet fluorescence (FL) were prepared. The effects of the lateral size and the polymerization temperature on the optical properties of CNNs have been studied. The ultraviolet FL was proved to have originated from the isolated melem units according to the density functional theory calculation and mass spectra. The obtained CNNs are further used as a pH probe due to the dependence of the FL signal on the pH of the solution.

14.
Analyst ; 145(1): 132-138, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31746827

RESUMO

This study reports a surface-enhanced electrochemiluminescence (SEECL) sensor for the ultrasensitive detection of prostate-specific antigen (PSA) in human serum. First, we prepared the Au-SiO2 core-shell nanocomposites doped with Ru(bpy)32+ (Au@SiO2-Ru) as the ECL signal generation and amplification element of the SEECL sensor. Ru(bpy)32+ could emit ECL under the excitation of an electrochemical reaction, and generate the local surface plasmon resonance (LSPR) electromagnetic field from the gold nanoparticle (AuNP) core. The produced LSPR then effectively enhanced the ECL signals. This sensing strategy was utilized for the detection of PSA, which can be absorbed on the electrode surface by the reaction between PSA and monoclonal antibodies. When polyclonal antibody-modified Au@SiO2-Ru was added, the PSA-double-antibody sandwich structure was formed on the electrode surface and thus, the Au@SiO2-Ru were quantitatively immobilized on the electrode surface. The results show that this kind of SEECL sensor has good selectivity toward PSA. Notably, the minimum detection concentration reached 7 × 10-7 ng mL-1 under the optimum experimental conditions, which is much better than most of the previously reported approaches for the detection of PSA in serum.

15.
Anal Chem ; 91(22): 14751-14756, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31651147

RESUMO

Ribonuclease A (RNase A) is increasingly considered as a biomarker for tumor diagnosis, and it is of great significance to develop an ultrasensitive, cost-effective assay for RNase A detection. Electrochemiluminescence (ECL) technology has distinctive advantages in the development of biosensors for diverse targets. However, most of the ECL biosensors require the complex process of electrode modification, which is laborious and time consuming. In this work, an immobilization-free homogeneous ECL assay was developed for the highly sensitive detection of RNase A activity for the first time. On the basis of the fact that RNase A can specifically hydrolyze RNA at the site of ribonucleotide uracil (rU), a rU-containing chimeric DNA probe is designed and labeled with Ru(bpy)32+ (act as ECL indicator). The chimeric DNA probe hardly diffuses to the surface of negatively charged indium tin oxide (ITO) electrode due to the strong electrostatic repulsion between the negatively charged DNA and ITO electrode, resulting in a weak ECL signal detected. When the RNase A is present, the chimeric DNA probe is hydrolyzed into small fragments, which contains little negative charge and can diffuse easily to the ITO electrode surface due to the decreased electrostatic repulsion. In this case, an enhanced ECL signal can be detected. Under the optimal conditions, there is a linear relationship between the ECL signal and the concentration of RNase A in the range of 0.001-0.10 ng/mL, and the detection limit is 0.2 pg/mL. In addition, the proposed ECL sensing system is also applied to detect the RNase A inhibitor, taking As3+ as an example. The proposed homogeneous ECL sensing system provides a new approach for the highly sensitive and convenient detection of RNase A as well as other ribonucleases only by redesigning a responding chimeric DNA probe.

16.
Chem Commun (Camb) ; 55(86): 12980-12983, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31603440

RESUMO

Nuclear factor kappa B p50 (NF-κB p50) induces various biological processes. In this study, a highly selective and sensitive electrochemiluminescence (ECL) biosensor for the detection of NF-κB p50 has been developed, which combines the high selectivity of the proximity hybridization assay (PHA) with the high efficiency of the hybridization chain reaction (HCR).


Assuntos
Técnicas Biossensoriais/métodos , Subunidade p50 de NF-kappa B/análise , DNA/química , Técnicas Eletroquímicas , Eletrodos , Humanos , Medições Luminescentes , Técnicas de Amplificação de Ácido Nucleico , Hibridização de Ácido Nucleico
17.
Anal Chem ; 91(21): 13712-13719, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31588727

RESUMO

With the development of clinical medicine-related technologies, the detection of cancer biomarkers has become an essential method for cancer diagnosis. DNA self-assembly is a valuable approach to monitor low-abundance miRNA. Herein, we report a novel DNA jungle biosensor for target-induced enzyme-free and label-free ultrasensitive detection of miRNA-21 in biological samples. The method consists of two parts. The target catalyzes the assembly of the hairpin to form the backbone of the DNA jungle, and the auxiliary probes hybridize to form branches freely and undirectedly. The DNA jungle can be self-assembled seeded from a single target initiator, affording the potential for screening a single target molecule. Vitro assays show that the DNA jungle offers very high amplification efficiency and specificity, with a direct detection limit of 1 aM. This DNA jungle strategy can provide a useful platform for low-abundance biomarker detection for cell biology and diagnostics.

18.
ACS Sens ; 4(9): 2465-2470, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31525917

RESUMO

Lead ions (Pb2+) cause harm to human health. Therefore, the development of fast, effective, and convenient sensors for Pb2+ monitoring has received great attention. In this study, a portable method has been proposed for Pb2+ detection using normal electronic balance as a readout. Magnetic bead-catalytic strand is hybridized with platinum nanoparticles (Pt NPs) functioned substrate strand (Pt-Sub) to form double-stranded DNA first. In the presence of Pb2+, the DNAzyme is activated and cleaved at the ribo-adenosine site of the substrate strand and hence causes Pt NPs to be released into the supernatant, which can be easily separated from the Pt-Sub by a magnet. The separated Pt NPs can effectively catalyze the decomposition of H2O2 to produce O2. In a sealed bottle, the pressure inside the bottle is increased by the generation of oxygen so that the water is discharged from the drainage device, and the weight of the water can be easily and precisely measured by a normal electronic balance. The weighting water has a linear relationship with the concentration of Pb2+ in the range of 2.5-100 nM and the detection limit of 0.83 nM (S/N = 3). The proposed method has been applied to detect Pb2+ in water with satisfactory results. Because the electronic balance is one of the most commonly used analytical tools for the laboratory, it is very practical and convenient without the need for expensive instruments and complicated data processing.

19.
Int J Biol Macromol ; 140: 206-215, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31415856

RESUMO

Tetrastigma hemsleyanum Diels et Gilg (THDG) is used as a Chinese traditional anti-inflammatory medicine for about thousands of years. In this work, Tetrastigma hemsleyanum Diels et Gilg's polysaccharide (TP) can inhibit E. coli's growth in initial dosing period. Compared with the antibacterial effect of Achyranthe's polysaccharide (AP) from their metabolic profile, it's obviously that their metabolic sites for E. coli were inconsistent. Moreover, TP could not only increase the level of fructose-6-phosphate (F6P), decrease the level of fructose-1,6-diphosphate (FBP), but also charge the amount of the two differential metabolic with the change of the concentration and the dosing time. Actually, F6P could transform into FBP by catalyze of 6-phosphofructokinase-1(6-PFK-1), which is an important process in glycolysis. Furthermore, FBP was considered have positively correlated with E. coli's growth rate. Therefore, TP can inhibit the E. coli's proliferation by interfering with the process for glycolysis and gluconeogenesis. Based on the experimental result, we proposed a new mouthwash method to evaluate the anti-bacterial activity. Compared with AP, TP can inhibit the E. coli's growth within 2 h with a low concentration (0.5%) and a short dosing time (5 min). This study extends the applications of THDG and establishes a new assessment method for the pharmacology activity of Chinese herbal medicine.

20.
Anal Chem ; 91(18): 11821-11826, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31436088

RESUMO

The development of simple but sensitive methods for hyaluronidase (HAase) detection has been paid a great deal of attention because HAase is a potential cancer marker. In this work, a novel system coupled with a controlled release system has been designed for HAase determination without complex analytical instruments and skilled technicians. Pt@SiO2 nanoparticles (NPs), which can catalyze the breakdown of H2O2 into O2 and H2O, was embedded in the hydrogel constructed by polyethylenimine (PEI) and hyaluronic acid (HA). In the presence of HAase, the hydrogel was broken down as HAase can catalyze the degradation of HA and hence the Pt@SiO2 NPs in the hydrogel was released. The released Pt@SiO2 NPs mixed with H2O2 solution in a drainage device, and then O2 was generated due to the decomposition of H2O2, resulting in an enhancement of pressure in the drainage device because of the low solubility of O2. A certain amount of H2O overflowed from the drainage device because the difference of the pressure between the inner and outer of the drainage device. The overflowed H2O was collected by a tube, and its amount was easily measured by an electronic balance. The weight of the H2O has a linear relationship with the HAase concentration in the range of 1-60 U/mL (120 min enzymatic hydrolysis time) and 0.2-10 U/mL (240 min enzymatic hydrolysis time). The developed system has been applied to detect the activity of HAase in urine samples with satisfied results.

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