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BACKGROUND: Patients with interstitial cystitis/bladder pain syndrome (IC/BPS) commonly face a decline in their quality of life and social functioning upon discontinuation of conventional therapy, which is known for its limited efficacy and the risk of relapse. While the existing evidence is somewhat restricted, acupuncture is being explored as a potential and effective treatment option for IC/BPS. CASE PRESENTATION: A 67-year-old woman, diagnosed with refractory IC/BPS, underwent treatment at the Medical Acupuncture Department of Sanming Integrated Traditional Chinese and Western Medicine Hospital. She reported symptoms of lower urinary system dysfunction, including urgency, frequency, and nocturia, along with chronic pelvic pain, and a persistent feeling of pressure and discomfort lasting over 8 years. The patient's visual analog scale (VAS) score for pelvic pain was 7 points prior to receiving acupuncture treatment. Throughout the day, she had more than 10 urinations, and at night, she urinated about once per hour. The O'Leary-Sant interstitial cystitis symptom index/interstitial cystitis problem index (ICSI/ICPI) score was 34 points, and the pelvic pain and urgency frequency (PUF) score was 19 points. RESULTS: The patient's complaints were significantly alleviated after 12 sessions of electroacupuncture treatment at BL32, BL33, BL35, and SP6 over 4 weeks. The patient claimed total relief from pelvic pain, with a VAS score of 0. The patient achieved a PUF score of 4 points and an ICSI/ICPI score of 7 points. In addition, there was a significant reduction in the frequency and urgency of urination. The patient experienced a frequency of 4-5 urinations during the day and 1-2 times at night. Subsequently, the patient's mental state and sleep quality were improved. The patient's symptoms did not change at one-year follow-up. CONCLUSION: Electroacupuncture has proven to be an effective management method for IC/BPS, as evidenced by the patient's alleviated lower urinary system symptoms and reduced pelvic pain.
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Locating underground pipeline leaks can be challenging due to their hidden nature and variable terrain conditions. To sample soil gas, solid-phase microextraction (SPME) was employed, and a portable gas chromatography/mass spectrometry (GC/MS) was used to detect the presence and concentrations of petroleum hydrocarbon volatile organic compounds (pH-VOCs), including benzene, toluene, ethylbenzene, and xylene (BTEX). We optimized the extraction method through benchtop studies using SPME. The appropriate fibre materials and exposure time were selected for each BTEX compound. Before applying SPME, we preconditioned the soil vapour samples by keeping the temperature at around 4 °C and using ethanol as a desorbing agent and moisture filters to minimize the impact of moisture. To conduct this optimisation, airbags were applied to condition the soil vapour samples and SPME sampling. By conditioning the samples using this method, we were able to improve analytical efficiency and accuracy while minimizing environmental impacts, resulting in more reliable research data in the field. The study employed portable GC/MS data to assess the concentration distribution of BTEX in soil vapour samples obtained from 1.5 m below the ground surface at 10 subsurface vapour monitoring locations at the leak site. After optimization, the detection limits of BTEX were almost 100 µg/m3, and the measurement repeatabilities were approximately 5% and 15% for BTEX standards in the laboratory and soil vapour samples in the field, respectively. The soil vapour samples showed a hotspot region with high BTEX concentrations, reaching 30 mg/m3, indicating a diesel return pipeline leak caused by a gasket failure in a flange. The prompt detection of the leak source was critical in minimizing environmental impact and worker safety hazards.
Assuntos
Petróleo , Microextração em Fase Sólida , Cromatografia Gasosa-Espectrometria de Massas/métodos , Microextração em Fase Sólida/métodos , Petróleo/análise , Derivados de Benzeno/análise , Tolueno/análise , Benzeno/análise , Xilenos/análise , Solo , Medição de RiscoRESUMO
Lindera aggregata (Sims) Kosterm. is a traditional Chinese herb, which has been proven to have excellent antibacterial activity. In this work, we firstly extracted the polysaccharides from the leaves of Lindera aggregata (Sims) Kosterm. (LLPs), and explored their antibacterial activity and related mechanisms. The experimental results show that LLPs are a good antibacterial agent, which can damage the cell structure of bacteria and lead to the leakage of intracellular lysates. Compared with Escherichia coli (E. coli), LLPs showed better inhibitory activity against Staphylococcus aureus (S. aureus). Furthermore, the administration of LLPs not only led to the upregulation of the levels of fructose-1,6-bisphosphate (F-1,6-P) and citric acid in the glycolysis and tricarboxylic acid cycle pathways in bacteria, but also resulted in the down-regulation of the levels of oxaloacetate (OAA) and 1,3-diphosphoglycerate (1,3-BPG). This study confirmed that LLPs have good antibacterial activity, and broaden the application of the leaves of Lindera aggregata (Sims) Kosterm. in the antibacterial field. It provides ideas for exploring the antibacterial mechanism of active ingredients of Chinese herbal medicine through metabolomics.
Assuntos
Lindera , Lindera/química , Cromatografia Líquida de Alta Pressão , Escherichia coli , Staphylococcus aureus , Polissacarídeos/farmacologia , Antibacterianos/farmacologiaRESUMO
Co-delivery of anti-inflammatory drugs and reactive oxygen species (ROS) scavengers by stimuli-responsive oral nanoparticles is deemed to be a favorable strategy for inflammatory bowel disease (IBD) therapy. In this study, using micelles formed by CUR conjugated hydroxyethyl starch (HES) as vehicles, dexamethasone (DEX)-loaded HES-CUR nanoparticles (DHC NPs) with desirable size, negative surface charge, good stability in the harsh gastric environment, and excellent ROS scavenging activity are developed as a colon-targeted oral formulation for treating IBD. Due to the degradation of HES in response to α-amylase overexpressed in the inflamed colon, the DHC NPs release drugs in an α-amylase-responsive manner. Meanwhile, the DHC NPs can be effectively internalized by macrophages and show excellent cytocompatibility with macrophages since they are composed of food-derived compounds. Importantly, in vivo studies reveal that the DHC NPs are capable of targeting the inflamed colon induced by dextran sulfate sodium (DSS), and the targeted and combination therapy enhances the efficacy of free DEX and significantly relieves the impairment caused by DSS-induced ulcerative colitis. Incorporating the merits of targeted drug delivery and combined therapy with an anti-inflammatory drug and ROS scavenger, the DHC NPs are promising for developing novel oral formulations for IBD therapy.
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Colite Ulcerativa , Curcumina , Nanopartículas , Animais , Anti-Inflamatórios , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Curcumina/farmacologia , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Amido , alfa-AmilasesRESUMO
The amount of copper affects the quality of herbal medicine greatly, it is necessary to develop some simple and sensitive methods to detect copper for the remote or resource-limited area. An electronic balance is one of the most familiar equipment that can be found nearly in all laboratories. The presence of Cu(i) can catalyze azide-alkyne cycloaddition reaction (called as click chemistry) with high efficiency. In this study, a simple method had been developed to detect copper ions in herbal medicine using an electronic balance as a readout device based on click chemistry. Cu(ii) is reduced to Cu(i) by sodium ascorbate in situ, which induces the "click" reaction between azido-DNA modified magnetic beads (MB-DNA) and alkynyl-DNA modified platinum nanoparticles (Pt NP-DNA) and results in the fixing of the platinum nanoparticles on the beads (called as MB-Pt NPs). MB-Pt NPs can be separated by a magnetic frame easily and transferred into a drainage reaction device containing hydrogen peroxide. Then, hydrogen peroxide can be decomposed by Pt NPs modified on MB to generate oxygen, which increases the pressure in the drainage reaction device and forces the water in the system to be discharged. The weight of the discharged water can be easily and accurately measured by an electronic balance. The weight of the water has a linear relationship with Cu(ii) in the range of 2.0-200 µM and a detection limit of 0.83 µM under 30 min of collected time. This method does not need complicated and expensive instruments, skilled technicians, and a complex data processing process. The proposed method had been applied to detect copper ions in herbal medicine with satisfactory results.
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Química Click , Nanopartículas Metálicas , Cobre , Eletrônica , Medicina Herbária , Íons , PlatinaRESUMO
We extracted and purified oxyresveratrol (OXY) from Artocarpus heterophyllus Lam. and identified its structure. The kinetics and mechanisms of OXY-induced mushroom tyrosinase inhibition were studied using fluorescence spectroscopy, copper ion chelation, and circular dichroism (CD). We found that OXY significantly inhibited tyrosinase with a half maximal inhibitory concentration (IC50) of 0.03 mM. The inhibitory effect of OXY on tyrosinase was almost 25 times that of kojic acid, which had an IC50 of 0.78 mM. Additionally, OXY and the tyrosinase substrate L-dopa did not have a competitive relationship; OXY is a non-competitive inhibitor. Using a fluorescence quenching experiment, we determined the corresponding rate constant (Kq) values at 298, 303, and 310 K to be 2.24 × 1012, 1.08 × 1012 and 1.44 × 1012 L mol-1 s-1, respectively. The OXY and tyrosinase interaction occured mainly through van der Waals forces and a hydrogen bond between the -OH group and its amino acid residue. Furthermore, we investigated the effects of OXY on murine melanoma B16 cells and on age pigments in Caenorhabditis elegans (C. elegans). OXY decreased melanin production by inhibiting the tyrosinase activity in murine melanoma B16 cells, which decreased superoxide dismutase (SOD) and glutathione peroxidase (GSH) and increased catalase (CAT), leading to apoptosis. The lifespan of nematodes in the 50 ml resveratrol-treated group was significantly longer than that in the blank group by 5%. The mean lifespan of nematodes in the 50 µM OXY-treated group was significantly longer than that in the blank group by 6.82%.The fluorescence intensity of C. elegans pigments decreased by 30.43%, 47.35% and 64.42% after the treatment with a low, middle, and high OXY dose, respectively, showing that OXY has a significant inhibitory effect on melanin and age pigment production.
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Monofenol Mono-Oxigenase/antagonistas & inibidores , Extratos Vegetais/farmacologia , Estilbenos/farmacologia , Agaricales/enzimologia , Animais , Apoptose/efeitos dos fármacos , Artocarpus/química , Caenorhabditis elegans , Melaninas/biossíntese , Melanoma/metabolismo , Melanoma/patologia , Melanoma Experimental , Camundongos , Monofenol Mono-Oxigenase/química , Monofenol Mono-Oxigenase/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Conformação Proteica/efeitos dos fármacos , Pigmentação da Pele/efeitos dos fármacos , Estilbenos/isolamento & purificação , Fatores de TempoRESUMO
Pseudostellaria heterophylla is a very popular traditional Chinese medicine herb, also called "Taizishen." Discrimination of P. heterophylla from different regions is critical for ensuring the effectiveness of drug use, because the drug effects of P. heterophylla from different regions are diversity of each other. To discriminate P. heterophylla from different regions rapidly and effectively, a model extracted by competitive adaptive reweighted sampling (CARS) was established. Original spectra of P. heterophylla in wave number range of 10,000 to 4,000 cm-1 were acquired. Orthogonal partial least squares discriminant analysis (OPLS-DA) was also used to establish a suitable model. CARS was performed for extracting key wave number variables. We found that the near-infrared spectrum of a series of samples analyzed by Row-center-SG, CARS, and OPLS-DA can effectively distinguish the P. heterophylla from different regions, and the accuracy of OPLS-DA model is also satisfactory in terms of good discrimination rate. These results show that the Row-center-SG, CARS, and OPLS-DA model can be used to identify the P. heterophylla from different regions. PRACTICAL APPLICATION: According to our research results, we can draw a conclusion that our research results may be used to distinguish the traditional Chinese medicine from those from different places of origin and the powder with similar appearance.
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Caryophyllales/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , China , Análise Discriminante , Análise dos Mínimos Quadrados , Pós/químicaRESUMO
A triazole-stabilized fluorescence sensor is developed for copper detection in the study. Tris-(benzyltriazolylmethyl)amine (TBTA) is used to improve the sensitivity and stability for the sensing system. A series of comparative experiments are performed with and without TBTA. In the presence of TBTA, the fluorescence decrease ratio is enhanced from 2.46 to 118.25; the detection limit is reduced from 67 nM to 3.6 nM; the higher selectivity toward copper compared to the other metal ions is verified, including K+, Ca2+, Cd2+, Zn2+, Mg2+, Mn2+, Pb2+, Hg2+, Fe3+ and Cr3+. Besides, the sensing system is successfully applied for copper determination in complex tea samples and chicken feed samples with the recovery range of 91.67-116.8%. A good consistency between the presented sensor and the flame atom absorbance spectrometry (FAAS) is confirmed by the low relative errors with the range from -2.39% to 7.02%.
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Ração Animal/análise , Cobre/análise , Análise de Alimentos/métodos , Espectrometria de Fluorescência/métodos , Chá/química , Fluorescência , Corantes Fluorescentes/química , Limite de Detecção , Metais/análise , Compostos Organometálicos/química , Sensibilidade e Especificidade , Triazóis/químicaRESUMO
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) ofâ¯less thanâ¯10% and an average enhancement factor (EF) of 1â¯×â¯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 1â¯min, with a limit of detection of 0.5⯵g/L. Compared with conventional ELISA based AFB1 analysis, our method is much more efficient (1â¯min versus >30â¯min).
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Aflatoxina B1/análise , Arachis/química , Nanoestruturas/química , Extratos Vegetais/química , Análise Espectral Raman/métodos , Óxido de Alumínio/química , Arachis/metabolismo , Ouro/química , Limite de DetecçãoRESUMO
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 2â¯h with a low concentration (0.5%) and a short dosing time (5â¯min). This study extends the applications of THDG and establishes a new assessment method for the pharmacology activity of Chinese herbal medicine.
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Achyranthes/química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Metabolômica , Polissacarídeos/farmacologia , Vitaceae/química , Antibacterianos/química , Medicamentos de Ervas Chinesas , Escherichia coli/crescimento & desenvolvimento , Espectrometria de Massas , Medicina Tradicional Chinesa , Folhas de Planta/química , Polissacarídeos/químicaRESUMO
A rapid method is described for the preparation of a highly uniform and sensitive SERS substrate by an improved 'drop-and-dry' method. Gold nanobipyramids (Au NBPs) were prepared inside the nanoholes (nanowalls) of anodic aluminum oxide (AAO) templates with a typically 5-µm nanohole depth. The SERS substrate can be prepared by this method within 40 s and on large scale. The SERS signals obtained with this Au NBPs-AAO substrate is stronger by four-orders of magnitude compared to conventional a silicon wafer substrate. The SERS signal for dopamine (DA; measured at 1311 cm-1) is found to be enhanced by a factor of 2.2 × 108. The response to DA extends from 10 nM to 0.1 mM, and the limit of detection is 6.5 nM (at S/N = 3). The assay was applied to the determination of DA in spiked human serum. Graphical abstract Schematic presentation of a highly active and uniform 3-dimensional substrate composed of gold nanobipyramids and anodic aluminum oxide (Au NBP/AAO). It was used for on-spot sensing of dopamine.
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Dopamina/sangue , Nanopartículas Metálicas/química , Óxido de Alumínio/química , Ouro/química , Humanos , Limite de Detecção , Estudo de Prova de Conceito , Reprodutibilidade dos Testes , Análise Espectral Raman/métodosRESUMO
In this study, a novel polysaccharide TDGP-3 from Tetrastigma hemsleyanum Diels et Gilg was extracted by enzymolysis-ultrasonic assisted extraction (EUAE) method and its antioxidant and hypolipidemic activities were evaluated. With a molecular weight of 3.31â¯×â¯105â¯Da, TDGP-3 was composed of 1,4-Glcp, 1,4-Glap and 1,3,6-Manp linkage in the main chain. TDGP-3 showed potential effects on relieving hyperlipidemia and preventing oxidative stress, reflecting by regulating blood lipid levels (TC, TG, HDL-C and LDL-C), decreasing the contents of MDA in liver, restoring the activities of hepatic antioxidant enzymes (SOD, GSH-Px and CAT). The results clearly indicated that the TDGP-3 possesses a potent hypolipidemic activity and might be used for hyperlipidaemia treatment.
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Antioxidantes/química , Hiperlipidemias/tratamento farmacológico , Hipolipemiantes/química , Polissacarídeos/química , Vitaceae/química , Animais , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Sequência de Carboidratos , Catalase/metabolismo , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Glutationa Peroxidase/metabolismo , Hiperlipidemias/metabolismo , Hiperlipidemias/fisiopatologia , Hipolipemiantes/isolamento & purificação , Hipolipemiantes/farmacologia , Extração Líquido-Líquido/métodos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/fisiopatologia , Testes de Função Hepática , Masculino , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Peso Molecular , Estresse Oxidativo , Extratos Vegetais/química , Folhas de Planta/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Sonicação , Superóxido Dismutase/metabolismo , Triglicerídeos/sangueRESUMO
Tetrastigma hemsleyanum Diels & Gilg, a well-known traditional Chinese medicine, possesses antitumor and anti-inflammatory activity, etc. However, the anti-diabetic effect has not been determined. In our present study, a water-soluble polysaccharide, named THP with molecular weight of 93 307 Da, was isolated from T. hemsleyanum by DEAE-52 ion-exchange and Sephadex G-100 chromatography. It contains rhamnose, arabinose, mannose, glucose, and galactose in the molar ratio of 0.07:0.14:0.38:0.21:0.31. Then anti-diabetic effects of THP were examined by treating alloxan-induced diabetic mice with different doses (100, 200, and 300 mg/kg) of THP orally. The results showed that THP could decrease the blood glucose, TC, TG, LDL-C levels, increase the body weight, HDL-C, insulin levels, and enhance the activities of antioxidant enzyme system in alloxan-induced diabetic mice. Furthermore, the histopathological examination of pancreas, liver, and kidney indicated that THP could protect and reverse ß-cells in diabetic mice with low damage to liver and kidney, which suggests that THP may stimulate pancreatic release of insulin and can be an effectively potential candidate for diabetes mellitus.
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Antioxidantes/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/farmacologia , Polissacarídeos/farmacologia , Vitaceae/química , Aloxano , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/patologia , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Masculino , Medicina Tradicional Chinesa , Camundongos , Camundongos Endogâmicos ICR , Tamanho do Órgão/efeitos dos fármacos , Polissacarídeos/química , Polissacarídeos/isolamento & purificaçãoRESUMO
In most aptamer based stimulus response mesoporous silica nanoparticles (MSN) systems, the aptamer is modified on the MSN via electrostatic interaction, however leakage might exist after a certain time in the system and hence the stability is not good. In this study, the pores of MSN were capped by aptamer through click chemistry reaction for the first time and the system was then employed to develop a fluorescence biosensor. Specifically, the aptamer of the target (thrombin in this study) was hybridized with its complementary DNA (which was initially modified with alkyne at the terminal) to form a double strand DNA (dsDNA) firstly, and then this dsDNA was modified on N3 modified MSN via Cu(I) catalyzed alkyne-azide cycloaddition reaction. The guest molecules (fluorescein) were blocked in the pores of the MSN with high efficiency and nearly no leakage was detected. Upon the introduction of thrombin, thrombin specifically recognized its aptamer, so aptamer released from the MSN; and the single strand DNA(ssDNA) left could not cap the pores of the MSN efficiently and hence caused the releasing of fluorescein into the solution. The enhanced fluorescence intensity of the system has a good linear relationship with the thrombin concentration in the range of 50-1000ngmL-1 with a detection limit of 28.46ngmL-1. The proposed biosensor has been successfully applied to detect thrombin in serum samples with high selectivity. The same strategy can be applied to develop biosensors for different targets by changing the adopted aptamer.
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Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas/química , Dióxido de Silício/química , Trombina/análise , Química Click , DNA/química , FluorescênciaRESUMO
Seed-mediated synthesis of gold nanorods (AuNRs) has been widely used for diverse applications in the past decade. In this work, this synthetic process is demonstrated for multicolor biosensing for the first time. Our investigation reveals that ascorbic acid acts as a key factor to mediate the growth of AuNRs. This phenomenon is incorporated into the alkaline phosphatase (ALP)-enzyme-linked immunosorbent assay (ELISA) system based on the fact that ALP can catalyze the conversion of ascorbic acid-phosphate into ascorbic acid with high efficiency. This allows us to develop a multicolor ELISA approach for sensitive detection of disease biomarkers with the naked eye. We show the proof-of-concept multicolor ELISA for the detection of prostate-specific antigen (PSA) in human serum. The results show that different colors are presented in response to different concentrations of PSA, and a detection limit of 3 × 10(-15) g mL(-1) in human serum was achieved. The proposed multicolor ELISA could be a good supplement to conventional ELISA for POC diagnostics.
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An ultrasensitive and specific electrochemiluminescence (ECL) biosensor has been designed for the p53 DNA sequence, which is based on cascade signal amplification of nicking endonuclease assisted target recycling and hyperbranched rolling circle amplification (HRCA). First of all, biotin modified hairpin capture DNA (HP) probe was immobilized on the surface of streptavidin magnespheres paramagnetic particles (PMPs). Target DNA hybridized with the loop portion of the HP probe, therefore unfolding HP to form a double-stranded DNA (dsDNA) containing the specific nicking site of the nicking endonuclease. Then, the nicking endonuclease recognized the specific nicking site and cleaved the HP into two pieces, liberating target DNA and the complementary sequence piece for the padlock probe. The intact target DNA would initiate the next cycle of hybridization and cleavage, thereby releasing multiple complementary sequences for the padlock probes. The liberated complementary sequences hybridized with the padlock probes, subsequently inducing the HRCA reaction and generating numerous dsDNA segments. Herein, Ru(phen)3(2+) was embedded into dsDNA and worked as ECL signal reporter. The reaction products were eventually pretreated by dialysis tube with the cutoff membrane to remove the residual Ru(phen)3(2+) in the solution for the following ECL measurements. Using this cascade amplification strategy, an ultrasensitive p53 DNA sequence detection method was developed with a wide linear range from 0.05 to 100 fM and a low detection limit of 0.02 fM. Moreover, this cascade amplified ECL biosensor had specific recognition capacity for noncomplementary and single- and double-base mismatched DNA. The proposed ECL biosensor might have a great potential in biomedical research and clinic analysis.
Assuntos
Técnicas Biossensoriais/métodos , DNA/sangue , Técnicas de Amplificação de Ácido Nucleico/métodos , Proteína Supressora de Tumor p53/genética , Sequência de Bases , DNA/genética , Sondas de DNA/química , Sondas de DNA/genética , Técnicas Eletroquímicas/métodos , Endonucleases/química , Humanos , Limite de Detecção , Medições LuminescentesRESUMO
The present paper presented a fast and non-destructive method for the discrimination of minnan oolong tea varieties by near-infrared spectroscopy technology. Two hundred ten samples including Tieguanyin, Huangjingui, Benshan, Maoxie and Meizhan were collected in different tea plantations of Minnan. NIR spectra of 1,100-1,300 nm and 1,640-2,498 nm were successfully obtained. Prediction model was built by principal component analysis (PCA), and the effects of multiplicative scatter correction (MSC) and standard normal variate (SNV) on the model were observed and compared. It was indicated that the effect of MSC on the model was superior for the effect of SNV because the classification accuracy of model for the calibration samples reached 96%, and this number to the prediction samples was about 90%. These results demonstrated that the near-infrared spectroscopy method established could be an efficient and accurate way for the discrimination of minnan oolong teas and would have a strong practical value.
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Análise de Alimentos , Espectroscopia de Luz Próxima ao Infravermelho , Chá/classificação , Modelos Teóricos , Análise de Componente PrincipalRESUMO
An RP LC-ESI-MS/MS method for the determination of the migration of 16 primary phthalic acid esters from plastic samples has been developed using distilled water, 3% acetic acid, 10% alcohol, and olive oil as food simulants. Detection limits were 1.6-18.5 µg/kg in distilled water, 1.4-17.3 µg/kg in 3% acetic acid, 1.4-19.2 µg/kg in 10% alcohol, and 31.9-390.8 µg/kg in olive oil. The RSDs were in the range of 0.07-11.28%. The real plastic products inspection showed that only few analyzed samples were phthalates contaminated. Bis-2-ethylhexyl ester and dibutyl phthalate were the common items migrated from the plastic products into food and feeds, but the migration concentrations were far below the limits set by European Union (1.5 mg/kg for bis-2-ethylhexyl ester and 0.3 mg/kg for dibutyl phthalate).