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1.
J Chromatogr A ; 1619: 460913, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32007220

RESUMO

Traditional boron affinity materials usually capture cis-diol-containing molecules under alkaline condition, but some cis-diol-containing molecules, such as polyphenols, are unstable and easy to be oxidized and degraded under alkaline condition. Teamed boronate affinity (TBA) can specifically capture cis-diol-containing molecules under neutral condition. However, the report about combination of TBA and magnetic nanoparticle for the extraction was rare. Here, we fabricated two kinds of teamed boronate affinity magnetic nanoparticles (TBAMP), including Fe3O4@TBAP and Fe3O4@SiO2@TBAP. Adsorption capacities of cis-diol-containing molecules on the latter were similar to these on the former, but the latter possessed more superior regeneration performance than the former. Therefore, the TBAMP with more superior regeneration performance was used as magnetic solid-phase extraction (MSPE) adsorbent for capturing polyphenols under neutral condition. The TBAMP MSPE was optimized in detail, and combined with high-performance liquid chromatography-mass spectrometry (HPLC-MS) for the simultaneous determination of 13 kinds of polyphenols from Flos Lonicerae Beverage. The proposed method showed low limit of detection between 0.01 and 0.20 ng mL-1. In blank Flos Lonicerae Beverage, 11 kinds of polyphenols ranged from 0.54 ng mL-1 to 52.99 ng mL-1 were detected. In the standard addition method, recoveries of cis-diol-containing polyphenols were between 85.7% and 102.1% with intra-day and inter-day relative standard deviation ranging from 3.2% to 5.1% and 5.3% to 7.3%, respectively.

2.
J Chromatogr A ; 1609: 460448, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31421793

RESUMO

In this work, we reported a simple two-step method for the synthesis of magnetic mesoporous epoxy resin (MMER), including one-pot template-free hydrothermal synthesis of nanoscale amine-functionalized magnetic nanoparticles (MN-NH2) and initiator-free ring-opening polymerization of epoxy resin. The resultant MMER was characterized in detail by transmission electron microscope (TEM), Fourier transform-infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS), thermogravimetic analysis (TGA) and magnetization curves. These results demonstrated successful synthesis of MMER with sufficient magnetic property and excellent thermal stability. The epoxy resin was covalent bonding MN-NH2 on and synthesized by hydrophobic monomers, so the MMER exhibited excellent adsorption quantity for hydrophobic bile acids. The MMER was used as magnetic solid-phase extraction (MSPE) sorbent, and combined with liquid chromatography-tandem mass spectrometry to extract and monitor 11 kinds of bile acids from serum sample. The proposed MSPE combined with LC-MS/MS method exhibited low limit of detection between 0.1 and 5 ng mL-1. In blank serum sample, 9 kinds of bile acids were detected, and ranged from -2.29 ng mL-1 to 6.86 ng mL-1. In standard addition recovery test, the recovery values of detectable bile acids ranged 102.4% to 108.5%, 96.0% to 104.0% and 82.3% to 103.3% when spiked with 0.2, 2.0 and 20 ng mL-1, respectively. The intra- and inter-day precision (n = 6) ranged 3.7% to 5.9% and 7.0% to 9.5%, respectively. The above results demonstrated that the MSPE combined with LC-MS/MS method was accurate and effective for quantitative determination of bile acids from complex biological samples.


Assuntos
Ácidos e Sais Biliares/sangue , Ácidos e Sais Biliares/isolamento & purificação , Resinas Epóxi/química , Fenômenos Magnéticos , Polimerização , Adsorção , Cromatografia Líquida , Humanos , Limite de Detecção , Nanopartículas/química , Nanopartículas/ultraestrutura , Porosidade , Extração em Fase Sólida , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Espectrometria de Massas em Tandem
3.
J Chromatogr A ; 1609: 460510, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31515077

RESUMO

In this study, a novel phenyl-boronic acid polymeric monolith (PBAPM) in polyether ether ketone (PEEK) tube was fabricated. The inner wall of PEEK tube was modified with mussel inspired polydopamine layer to firmly bond PBAPM, so as to avoid the outflow of PBAPM from PEEK tube and improve the service life and application scope of PBAPM. The PBAPM was synthesized by initiator-free ring-opening polymerization based on our previous work. The boric acid groups provided B-N coordination sites, as well as the hydrophobic amino and epoxy monomers provided hydrophobic interaction sites. Due to the synergistic effect of hydrophobic interaction and B-N coordination, the PBAPM exhibited excellent binding amounts for nitrogen-containing sulfonamides (SAs). In addition, the PBAPM possessed excellent stability, rigidity and permeability. Therefore, the PBAPM was used as solid phase microextraction (SPME) material for enrichment and separation of SAs from aqueous samples. The PBAPM SPME was optimized in detail, and combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis for simultaneous determination of 10 kinds of SAs from tap, lake and river water. Using only 1 mL of water samples, limit of quantitation of SAs could reach 0.54-4.5 ng L-1. Recoveries of standard spiked SAs from water samples were between 82.0% and 105.4%, with intra-day and inter-day relative standard deviation ranging from 3.3% to 5.6% and 4.2% to 8.1%, respectively. The PBAPM SPME combined with UPLC-MS/MS method shown better or similar recoveries, and used fewer samples than previous methods. These results demonstrated that the PBAPM could selectively separate and enrich ultra-trace nitrogen-containing SAs from aqueous samples.


Assuntos
Ácidos Borônicos/química , Cromatografia Líquida de Alta Pressão/métodos , Polimerização , Polímeros/química , Microextração em Fase Sólida , Sulfonamidas/análise , Espectrometria de Massas em Tandem/métodos , Sulfonamidas/química , Água/química , Poluentes Químicos da Água/análise
4.
J Chromatogr A ; 1590: 10-18, 2019 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-30609959

RESUMO

Boronate affinity materials are usually used for selective enrichment of cis-diol-containing compounds, mainly based on formation of pH-dependent cyclic ester between cis-diol and boronic acid. Recently, B-N coordination, or combined with hydrogen-bonding interaction, was employed as primary interaction for the extraction of nitrogen-containing compounds. However, there are no reports about the combination of hydrophobic (or π-π) interaction and B-N coordination for the extraction. Here, we prepared a novel hydrophobic phenyl-boronic acid polymer (PBAP) through initiator-free ring-opening polymerization. The adsorption experiment indicated that the PBAP could combine hydrophobic (or π-π) interaction and B-N coordination to enhance their adsorption capacity toward hydrophobic and nitrogen-containing compounds, for example sulfamethoxazole (SMX) and trimethoprim (TMP). In addition, the PBAP monolith synthesized in pipette tip was used as solid phase microextraction (SPME) sorbent with combination of ultra high performance liquid chromatography to extract and monitor SMX and TMP from animal-originated foodstuffs. The proposed method exhibited low limit of quantitation as 5.0 and 1.0 ng mL-1 for SMX and TMP, respectively. The recoveries at three spiked levels were between 92.4% to 100.5% for SMX, and 92.7% to 102.6% for TMP, with intra-day and inter-day relative standard deviations no more than 5.3% and 8.6%, respectively. These results well demonstrated that the combination of hydrophobic (or π-π) interaction and B-N coordination played an important role in the extraction of hydrophobic and nitrogen-containing compounds.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas , Produtos da Carne/análise , Microextração em Fase Sólida/métodos , Sulfametoxazol , Trimetoprima , Ácidos Borônicos/química , Resíduos de Drogas/análise , Resíduos de Drogas/química , Resíduos de Drogas/isolamento & purificação , Polímeros/química , Sulfametoxazol/análise , Sulfametoxazol/química , Sulfametoxazol/isolamento & purificação , Trimetoprima/análise , Trimetoprima/química , Trimetoprima/isolamento & purificação
5.
J Chromatogr A ; 1544: 23-32, 2018 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-29499841

RESUMO

A combination between modification with porous layer and grafting of polyethyleneimine (PEI) on the inner face of capillary was for the first time developed for boronate affinity in-tube solid-phase microextraction (SPME) material to enhance the extraction capacity for cis-diol-containing polyphenols. The successful synthesis of boronate-decorated polyethyleneimine-grafted porous layer open tubular (BPPLOT) capillary was confirmed by scanning electron micrograph, Fourier transform-infrared spectra and absorption experiments. The porous layer, PEI and boronate affinity provided high specific surface area, more binding sites for boronate groups and specific selectivity of BPPLOT capillary, respectively. The maximum binding quantity of BPPLOT capillary greatly improved, and ranged from 143 to 170 µg m-1 for cis-diol-containing polyphenols (catechin, chlorogenic acid, caffeic acid and epicatechin). A green method based on boronate affinity in-tube SPME was developed for separation and enrichment polyphenols, and some parameters of in-tube SPME were optimized. After in-tube SPME, HPLC with UV detection was used for quantitative determination of polyphenols. Recoveries of standard spiked cis-diol-containing polyphenols from fruit juice were between 80.9% and 102%, with intra-day and inter-day coefficient of variation ranging from 4.8% to 7.3% and 5.0% to 8.6%, respectively. Conversely, recovery of non-cis-diol-containing ferulic acid was no greater than 3.0%. These results suggested that the BPPLOT capillary could effectively separate and enrich cis-diol-containing polyphenols from real samples.


Assuntos
Ácidos Borônicos/química , Sucos de Frutas e Vegetais/análise , Polietilenoimina/química , Polifenóis/isolamento & purificação , Álcoois/química , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Cinética , Porosidade , Microextração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de Fourier , Chá/química , Temperatura
6.
Anal Bioanal Chem ; 410(1): 247-257, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29098333

RESUMO

In this work, we reported an effective method for the synthesis of a multirecognition magnetic molecularly imprinted polymer (MMIP) with atom transfer radical polymerization (ATRP), using 2,4-diamino-6-methyl-1,3,5-triazine as pseudo-template. The resulting MMIP was characterized in detail by Fourier transform-infrared (FT-IR) spectra, scanning electron microscopy (SEM), thermogravimetic analysis (TGA), and vibrating sample magnetometry (VSM). These results indicated the successful synthesis of MMIP with sufficient thermal stability and magnetic properties. The adsorption experiments were carried out to evaluate the specific selectivity of MMIP related to the spatial structure of target molecules. The MMIP exhibited multirecognition ability and excellent binding capability for melamine (MEL), cyromazine (CYR), triamterene (TAT), diaveridine (DVD), and trimethoprim (TME), and the apparent maximum number of binding sites (Q max) was 77.5, 75.2, 72.5, 69.9, and 70.4 µmol g-1, respectively. The multirecognition MMIP not only possessed adequate magnetic responsiveness for fast separation but also avoided the risk of template leakage on trace component analysis. Therefore, it was suitable for serving as a magnetic solid-phase extraction (MSPE) adsorbent. MSPE coupled with high-performance liquid chromatography analysis was applied to enrich and separate five target molecules from three samples. Recoveries for all target molecules ranged from 81.6 to 91.5% with relative standard deviations of no more than 4.1% (n = 3). Graphical abstract Multirecognition property of magnetic molecularly imprinted polymer prepared with pseudo template.

7.
Oncotarget ; 8(39): 65601-65608, 2017 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-29029456

RESUMO

AIMS: To investigate the association of several single nucleotide polymorphisms (SNPs) within Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene and additional gene- gene and gene- type 2 diabetes mellitus (T2DM) interaction with pulmonary tuberculosis (PTB) risk in Chinese Uygur population. METHODS: A total of 722 participants (186 males, 536 females) were selected, including 360 PTB patients and 362 control participants. Generalized multifactor dimensionality reduction (GMDR) was used to screen the best interaction combination among SNPs and T2DM. Logistic regression was performed to investigate association between 3 SNPs within PTPN22 gene, additional gene- gene and gene- T2DM interaction on PTB risk. RESULTS: Logistic regression analysis showed that PTB risk was significantly lower in carriers with rs2476601- CT genotype than those with CC genotype (CT versus CC), adjusted OR (95%CI) =0.42 (0.17-0.83), and higher in carriers with the rs33996649- GA genotype than those with GG genotype (GA versus GG), adjusted OR (95%CI) = 5.66 (2.24-9.47). We found a significant two-locus model (p=0.0010) involving rs33996649 and T2DM. Overall, the cross-validation consistency of this two- locus model was 10/ 10, and the testing accuracy was 60.11%. We also conducted stratified analysis for rs33996649 and T2DM using logistic regression. We found that T2DM patients with rs33996649 - GA genotype have the highest PTB risk, compared to non- T2DM patients with rs33996649- GG genotype, OR (95%CI) = 4.52 (2.71 -6.43), after covariates adjustment. CONCLUSIONS: We found that the T allele of rs2476601 and the A allele of rs33996649within PTPN22 gene, interaction between rs2476601 and T2DM were all associated with increased PTB risk.

8.
J Chromatogr A ; 1516: 125-130, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-28826619

RESUMO

Cell membrane chromatography (CMC) is an effective tool in screening active compounds from natural products and studying membrane protein interactions. Nevertheless, it always consumes a large amount of cells (e.g. 107-108) for column preparation. To overcome this, micro-CMC (mCMC), that employs a silica capillary as membrane carrier, was developed. However, both CMC and mCMC suffer from short column life span (e.g. 3days), mainly due to the falling-off of cellular membranes (CMs). This has greatly limited further application of CMC and mCMC, especially when the cells are hard to obtain. To solve this, N-hydroxysuccinimide (NHS)-modified silica-based porous layer open tubular capillary was first prepared for mCMC. The NHS groups can easily react with amino groups on CMs to form a stable covalent bond under a mild condition. So, CMs immobilized on the NHS-modified capillary are less likely to fall off. To verify this, SKBR3/mCMC (Her2 positive) and BALL1/mCMC (CD20 positive) columns were prepared. Two monoclonal antibody drugs, trastuzumab (anti-Her2) and rituximab (anti-CD20), were selected as analytes to characterize the columns. As a result, NHS-modified column for mCMC can afford higher chromatographic retention than non-modified column. Besides, the column life span was significantly improved to more than 16days for SKBR3/mCMC and 14days for BALL1/mCMC, while the compared column showed a sharp decline in retention factor in first 3days.


Assuntos
Técnicas de Química Analítica/instrumentação , Técnicas de Química Analítica/métodos , Cromatografia/instrumentação , Dióxido de Silício/química , Porosidade , Rituximab/análise , Succinimidas/química , Trastuzumab/análise
9.
J Chromatogr A ; 1509: 1-8, 2017 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-28629938

RESUMO

A combination between modification with nanoparticles (NP) and oriented antibody immobilization (OAI) on the inner face of capillary was for the first time developed for immunoaffinity in-tube solid-phase microextraction (SPME) to promise high antigen extraction capacity. ß2-microglobin (ß2MG) and cystatin C (Cys-C) were selected as model antigens. Poly(glycidyl methacrylate) (PGMA) NPs were chemically immobilized onto the capillary by a ring-opening reaction. Antibodies for ß2MG and Cys-C were immobilized on the NPs through OAI. Scanning electron micrograph of the OAI capillary clearly showed that the PGMA NPs were coated onto the inner surface of capillary in a dense monolayer. In addition, random antibody immobilized (RAI) capillaries and OAI capillaries without NP were also prepared as controls. The extraction capacities of OAI capillaries were 2.02 and 2.18mgm-1 for ß2MG and Cys-C, and were about 5 and 6 times as many as RAI capillaries and OAI capillaries without NP, respectively. The resultant capillaries were used as in-tube SPME materials to enrich ß2MG and Cys-C for particle-enhanced turbidimetric immunoassay. When using 1.0mgL-1 standard solutions, the recoveries of OAI capillaries, RAI capillaries and OAI capillaries without NP were 103.6% and 96.8%, 48.5% and 31.5%, and 24.2% and 25.7% for ß2MG and Cys-C, respectively. Furthermore, the method quantitation limit by OAI capillaries was 5 and 10 times lower than that by RAI capillaries and OAI capillaries without NP, respectively. This result indicated that the NP-coated capillaries with OAI are more suitable for using as immunoaffinity in-tube SPME materials than that with RAI.


Assuntos
Anticorpos/química , Nanopartículas/química , Ácidos Polimetacrílicos/química , Microextração em Fase Sólida/instrumentação
10.
Drug Des Devel Ther ; 11: 91-102, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28096657

RESUMO

BACKGROUND AND AIM: To conduct meta-analyses of all published studies on various aspects of association between vitamin D and tuberculosis (TB). METHODS: PubMed and Web of Knowledge were searched for all properly controlled studies on vitamin D and TB. Pooled odds ratio, mean difference or standardized mean difference, and its corresponding 95% confidence interval were calculated with the Cochrane Review Manager 5.3. RESULTS: A significantly lower vitamin D level was found in TB patients vs controls; vitamin D deficiency (VDD) was associated with an increased risk of TB, although such an association was lacking in the African population and in the human immunodeficiency virus-infected African population. A significantly lower vitamin D level was found in human immunodeficiency virus-TB-coinfected African patients receiving antiretroviral treatment who developed TB-associated immune reconstitution inflammatory syndrome vs those who did not develop TB-associated immune reconstitution inflammatory syndrome. VDD was associated with an increased risk of developing active TB in those subjects with latent TB infection and with an increased risk of tuberculin skin test conversion/TB infection conversion, and the trend toward a lower vitamin D level in active TB patients vs latent TB infection subjects did not reach statistical significance, indicating that VDD was more likely a risk factor than a consequence of TB. This concept was further strengthened by our result that anti-TB treatment did not affect vitamin D level in TB patients receiving the treatment. CONCLUSION: Our analyses revealed an association between vitamin D and TB. VDD is more likely a risk factor for TB than its consequence. More studies are needed to determine whether vitamin D supplementation is beneficial to TB prevention and treatment.


Assuntos
Tuberculose/sangue , Deficiência de Vitamina D/sangue , Antirretrovirais/uso terapêutico , Antituberculosos/uso terapêutico , Infecções por HIV/sangue , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Humanos , Fatores de Risco , Tuberculose/tratamento farmacológico , Tuberculose/imunologia , Deficiência de Vitamina D/imunologia
11.
Anal Bioanal Chem ; 409(1): 201-211, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27744483

RESUMO

In this study, a new molecularly imprinted polymer chiral stationary phase (MIP-CSP) was prepared utilizing molecular crowding agent for improvement the selective separation ability. S-amlodipine (S-AML), methacrylic acid (MAA), ethylene glycol dimethacrylate (EDMA), and polymethyl methacrylate (PMMA) were selected as template, functional monomer, cross-linker, and molecular crowding agent, respectively. The composition of formulas for MIP-CSP was optimized, and the permeability and structural feature of resultant MIP-CSP were characterized. The effect of mobile-phase composition, including ionic strength, pH, and organic modifier content, was investigated for achieving the selective separation of rac-amlodipine (rac-AML) on MIP-CSP. The baseline separation of rac-AML was achieved with resolution of 1.58, whereas no selective separation was observed on the imprinted monolith without molecular crowding agent. The perturbation chromatography method was successfully applied to evaluate the recognition mechanism of templates on MIP-CSP. The retention time of S-AML detected in typical analytical conditions was obviously greater than the time of negative peak derived from perturbation, which indicated the retention of template may be due to the imprinted cavities on MIP-CSP. Additionally, the result of Van't Hoff analysis indicated that the chiral separation of rac-AML on MIP-CSP was an entropy-driven process, which supported the molecular imprinting theory. These results reveal that molecular crowding is a potential strategy for preparation of MIP-CSP with excellent selective separation ability. Graphical Abstract Improvement of chiral separation on molecularly imprinted monolith by molecular crowding condition.

12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(3): 618-23, 2016 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-27400493

RESUMO

As a major error of CO2 retrieval, atmospheric scattering effect hampers the application of satellite products. Effect of aerosol and combined effect of aerosol and ground surface are important source of atmospheric scattering, so it needs comprehensive consideration of scattering effect from aerosol and ground surface. Based on the continuum, strong and weak absorption part of three spectrum bands O2-A, CO2 1.6 µm and 2.06 µm, information of aerosol and albedo was analyzed, and improved full physics retrieval method was proposed, which can retrieve aerosol and albedo simultaneously to correct the scattering effect. Simulation study on CO2 error caused by aerosol and ground surface albedo CO2 error by correction method was carried out. CO2 error caused by aerosol optical depth and ground surface albedo can reach up to 8%, and CO2 error caused by different types of aerosol can reach up to 10%, while these two types of error can be controlled within 1% and 2% separately by this correction method, which shows that the method can correct the scattering effect effectively. Through evaluation of the results, the potential of this method for high precision satellite data retrieval is obvious, meanwhile, some problems which need to be noticed in real application were also pointed out.

13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(1): 186-90, 2016 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-27228765

RESUMO

High precision retrieval of atmospheric CH4 is influenced by a variety of factors. The uncertainties of ground properties and atmospheric conditions are important factors, such as surface reflectance, temperature profile, humidity profile and pressure profile. Surface reflectance is affected by many factors so that it is difficult to get the precise value. The uncertainty of surface reflectance will cause large error to retrieval result. The uncertainties of temperature profile, humidity profile and pressure profile are also important sources of retrieval error and they will cause unavoidable systematic error. This error is hard to eliminate only using CH4 band. In this paper, ratio spectrometry method and CO2 band correction method are proposed to reduce the error caused by these factors. Ratio spectrometry method can decrease the effect of surface reflectance in CH4 retrieval by converting absolute radiance spectrometry into ratio spectrometry. CO2 band correction method converts column amounts of CH4 into column averaged mixing ratio by using CO2 1.61 µm band and it can correct the systematic error caused by temperature profile, humidity profile and pressure profile. The combination of these two correction methods will decrease the effect caused by surface reflectance, temperature profile, humidity profile and pressure profile at the same time and reduce the retrieval error. GOSAT data were used to retrieve atmospheric CH4 to test and validate the two correction methods. The results showed that CH4 column averaged mixing ratio retrieved after correction was close to GOSAT Level2 product and the retrieval precision was up to -0.24%. The studies suggest that the error of CH4 retrieval caused by the uncertainties of ground properties and atmospheric conditions can be significantly reduced and the retrieval precision can be highly improved by using ratio spectrometry method and CO2 hand correction method.

14.
Artigo em Inglês | MEDLINE | ID: mdl-26595796

RESUMO

Through precipitation polymerization, three monodisperse molecularly imprinted polymers (MIPs) containing imprints of 2,4-diamino-6-methyl-1,3,5-triazine (DM), cyromazine (CY) or trimethoprim (TM), were synthesized using methacrylic acid as functional monomer, divinylbenzene as cross-linker, and a mixture of acetonitrile-toluene (90/10, v/v) as porogen. The morphology and selectivity of the MIPs were characterized and compared systematically. The MIPs had the best specific binding in pure acetonitrile, and the data of adsorption experiment were fitted well with Langmuir and Freundlich model. In addition, DM-MIPs showed the excellent binding and multi-recognition capability for CY, melamine (ME), triamterene (TA) and TM, and the binding capacity were 7.18, 7.56, 5.66 and 5.45µmol/g, respectively. Due to the pseudo template and the ability of multi-recognition, DM-MIPs as sorbent material could avoid the effect of template leakage on quantitative analysis. Therefore, DM-MIPs were used as a solid-phase extraction material to enrich ME, CY, TA and TM from different bio-matrix samples for high performance liquid chromatography analysis. Under the optimized conditions, the recoveries of three spiked levels in different bio-matrix samples were ranged from 80.9% to 91.5% with RSD≤4.2 (n=3).


Assuntos
Microesferas , Polimerização , Triantereno/isolamento & purificação , Triazinas/isolamento & purificação , Trimetoprima/isolamento & purificação , Humanos , Limite de Detecção , Microscopia Eletrônica de Varredura , Triantereno/urina , Triazinas/urina , Trimetoprima/urina
15.
Int J Pharm ; 496(2): 822-33, 2015 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-26474963

RESUMO

This paper reported the facile fabrication of drug delivery devices for zero-order sustained release by molecular crowding strategy of molecularly imprinting technology. Crowding-assisted molecularly imprinting polymers (MIPs) matrices were prepared by free-radical precipitation polymerization using aminoglutethimide (AG) as a model drug. The crowding effect was achieved by adding polystyrene as a macromolecular co-solute in pre-polymerization mixture. The MIP prepared under the non-MMC condition and the two corresponding non-imprinted particles were tested as controlled vehicles. The release profiles presented zero-order behaviors from two crowding-assisted polymers, the duration of approximately 18h for the crowding-assisted MIP and 10h for the crowding-assisted NIP, respectively while AG were all very rapid released from the other two controlled particles (85% occurring in the first hour). The BET surface area and pore volume of the crowding-assisted MIP were about ten times than those of the controlled MIP. The value of imprinting factor is 6.02 for the crowding-assisted MIP and 1.19 for the controlled MIP evaluated by the equilibrium adsorption experiment. Furthermore, the values of effective diffusivity (Deff) obtained from crowding-assisted MIP (10(-17)cm(2)/s) was about two orders of magnitude smaller than those from the controlled MIP, although the values of free drug diffusivity (D) were all found in the order of 10(-13)cm(2)/s. Compared with the commercial AG tablet, the MMC-assisted MIP gave a markedly high relative bioavailability of 266.3%, whereas the MMC-assisted NIP gave only 57.7%. The results indicated that the MMC condition can modulate the polymer networks approaciate to zero-order release of the drug and maintain the molecular memory pockets, even if under the poor polymerization conditions of MIPs preparation.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Impressão Molecular/métodos , Aminoglutetimida/química , Animais , Preparações de Ação Retardada , Matemática , Polimerização , Poliestirenos/química , Ratos , Ratos Wistar , Solubilidade
16.
Anal Bioanal Chem ; 407(23): 7145-55, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26195027

RESUMO

Three fragmental templates, including 2,4-diamino-6-methyl-1,3,5-triazine (DMT), cyromazine (CYR), and trimethoprim (TME), were used to prepare the fragment molecularly imprinted polymers (FMIPs), respectively, in polar ternary porogen which was composed of ionic liquid ([BMIM]BF4), methanol, and water. The morphology, specific surface areas, and selectivity of the obtained FMIPs for fragmental analogues were systematically characterized. The experimental results showed that the FMIPs possessed the best specific recognition ability to the relative template and the greatest imprinting factor (IF) was 5.25, 6.69, and 7.11 of DMT on DMT-MIPs, CYR on CYR-MIPs, and TME on TME-MIPs, respectively. In addition, DMT-MIPs also showed excellent recognition capability for fragmental analogues including CYR, melamine (MEL), triamterene (TAT), and TME, and the IFs were 2.08, 3.89, 2.18, and 2.60, respectively. The effects of pH and temperature on the retention of the fragmental and structural analogues were studied in detail. Van't Hoff analysis indicated that the retention and selectivity on FMIPs were an entropy-driven process, i.e., steric interaction. The resulting DMT-MIPs were used as a solid-phase extraction material to enrich CYR, MEL, TAT, and TME in different bio-matrix samples for high-performance liquid chromatography analysis. The developed method had acceptable recoveries (86.8-98.6%, n = 3) and precision (2.7-4.6%) at three spiked levels (0.05-0.5 µg g(-1)).


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Impressão Molecular/métodos , Triantereno/análise , Triazinas/análise , Trimetoprima/análise , Misturas Complexas/análise , Misturas Complexas/química , Líquidos Iônicos/química , Polímeros/química , Triantereno/química , Triazinas/química , Trimetoprima/química
17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(3): 734-8, 2015 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-26117889

RESUMO

The effect of Mixed-hyperspectral in the water is difficult in quantitative remote sensing of water. Studies have shown that the only scalar spectrum information is difficult to solve the problem of complex mixed spectra of water. Besides the spectral information, spatial distribution of information is one of the obvious characteristics of the broad waters pollution, and can be used as a useful complement to the remote sensing information and facilitate water complex spectral unmixing. Taking Chaohu as an example, the paper applies the HJ-1A HSI hyperspectral data and the supplemental surface spectral measurement data to discuss the mixed spectra of lake water by spatial statistics and genetic algorithm theory. By using the spatial variogram of geostatistics to simulate the distribution difference of two adjacent pixels, the space-informational decomposition model of mixed spectral in lake water is established by co-kriging genetic algorithm, which is a improved algorithm applying the spatial variogram function of neighborhood pixel as the constraint of the objective function of the genetic algorithm. Finally, the model inversion results of suspended matter concentration are verified. Compared with the conventional spectral unmixing model, the results show the correlation coefficient of the predicted and measured value of suspended sediment concentration is 0.82, the root mean square error 9.25 mg x L(-1) by mixed spectral space information decomposition model, so the correlation coefficient is increased by 8.9%, the root mean square error reduced by 2.78 mg x L(-1), indicating that the model of suspended matter concentration has a strong predictive ability. Therefore, the effective combination of spatial and spectral information of water, can avoid inversion result distortion due to weak spectral signal of water color parameters, and large amount of calculation of information extraction because of the high spectral band numbers, and also provides an effective way to solve spectral mixture model of complex water and improve the accuracy of model inversion.

18.
Med Sci Monit ; 21: 1313-8, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25950148

RESUMO

BACKGROUND: The prevalence of drug-resistant tuberculosis (TB) in Xinjiang is higher than in other regions of China, and Beijing/W lineage Mycobacterium tuberculosis (MTB) is the dominant strain of MTB in Xinjiang. However, information on multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB, particularly the correlation between MDR and the Beijing/W lineage and the correlation between drug resistance and the Beijing/W sublineage strains, is limited. MATERIAL/METHODS: We conducted a prospective study to describe the prevalence of MDR/XDR TB, Beijing/W lineage and sublineage strains in Xinjiang in China from 2009 to 2013. All MTB underwent drug susceptibility testing to the first- and second-line anti-tuberculosis drugs. The Beijing/W lineages and sublineages were detected by large-sequence polymorphisms with polymerase chain reaction. RESULTS: A total of 410 clinical isolates were identified. The overall percentage of MDR and XDR cases in Xinjiang was 13.2% (54/410) and 13.0% (7/54), respectively. Overall, 9.8% (14/143) of the Beijing lineage MTB were MDR patients, and 15.6% (40/257) of the Non-Beijing lineage MTB were MDR patients. In the 143 Beijing MTB lineages, 11.2% isolates were in sublineage 105, 15.4% isolates were in sublineage 207, 69.2% isolates were in sublineage 181, and 4.2% isolates were in sublineage 150. None of the isolates were detected in sublineage 142. Significant differences between the Beijing/W and non-Beijing/W strains were observed regarding INH and EMB resistance, respectively. CONCLUSIONS: The prevalence of the MDR TB in Xinjiang remains high and imposes challenges for TB control. Four Beijing/W sublineage isolates were observed in Xinjiang. There was no correlation between MDR and the Beijing/W lineage and no correlation between drug resistance and the Beijing/W sublineage strains. Surveillance of the clinical isolates of MTB is recommended to strengthen the identification of MDR/XDR TB and sublineages of the Beijing/W strains.


Assuntos
Antituberculosos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Tuberculose Extensivamente Resistente a Medicamentos/microbiologia , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Adolescente , Adulto , Fatores Etários , Idoso , Antituberculosos/classificação , Antituberculosos/uso terapêutico , Criança , Pré-Escolar , China/epidemiologia , DNA Bacteriano/genética , Tuberculose Extensivamente Resistente a Medicamentos/epidemiologia , Feminino , Genes Bacterianos , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Prevalência , Estudos Prospectivos , Especificidade da Espécie , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Adulto Jovem
19.
Anal Bioanal Chem ; 406(22): 5359-67, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24916075

RESUMO

A thermoresponsive imprinted monolith with the ability of molecular recognition for ketoprofen was prepared for the first time. The smart monolith was synthesized in a stainless steel column using acrylamide (AAm) and 2-acrylamide-2-methyl propanesulfonic acid (AMPS) as functional monomers, which can form interpolymer complexation to restrict access of the analyte to the imprinted networks at low temperatures. To avoid a high back pressure of the column derived from neat dimethyl sulfoxide (DMSO) as a porogenic solvent that is needed to solve polar AMPS, an ionic liquid, [BMIM]BF4, was introduced into the pre-polymerization mixture. The molecular recognition ability towards ketoprofen of the resulting thermoresponsive molecularly imprinted polymer (MIP) monolith displayed significant dependence on temperature compared with a non-imprinted column (NIP), and the greatest imprinting factor was achieved at the transition temperature of 35 °C (above 10). Furthermore, the number of binding sites of the smart MIP monolith at 35 °C was about 76 times as large as that at 25 °C. In addition, Freundlich analyses indicated that the thermoresponsive MIP monolith had homogeneous affinity sites at both 25 and 35 °C with heterogeneity index 0.9251 and 0.9851, respectively.


Assuntos
Acrilamida/análise , Líquidos Iônicos/química , Cetoprofeno/química , Impressão Molecular , Ácidos Sulfônicos/análise , Acrilamida/química , Adsorção , Animais , Química Farmacêutica , Dimetil Sulfóxido/química , Contaminação de Alimentos , Gases , Concentração de Íons de Hidrogênio , Mercúrio , Leite/química , Polímeros/química , Porosidade , Pressão , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Ácidos Sulfônicos/química , Temperatura
20.
Sci China Life Sci ; 57(5): 495-501, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24699914

RESUMO

The mitochondria play essential roles in both intracellular calcium and reactive oxygen species signaling. As a newly discovered universal and fundamental mitochondrial phenomenon, superoxide flashes reflect transient bursts of superoxide production in the matrix of single mitochondria. Whether and how the superoxide flash activity is regulated by mitochondrial calcium remain largely unknown. Here we demonstrate that elevating mitochondrial calcium either by the calcium ionophore ionomycin or by increasing the bathing calcium in permeabilized HeLa cells increases superoxide flash incidence, and inhibition of the mitochondrial calcium uniporter activity abolishes the flash response. Quantitatively, the superoxide flash incidence is correlated to the steady-state mitochondrial calcium elevation with 1.7-fold increase per 1.0 ΔF/F 0 of Rhod-2 signal. In contrast, large mitochondrial calcium transients (e.g., peak ΔF/F 0 ∼ 2.8, duration ∼ 2 min) in the absence of steady-state elevations failed to alter the flash activity. These results indicate that physiological levels of sustained, but not transient, mitochondrial calcium elevation acts as a potent regulator of superoxide flashes, but its mechanism of action likely involves a multi-step, slow-onset process.


Assuntos
Cálcio/metabolismo , Mitocôndrias/metabolismo , Superóxidos/metabolismo , Compostos de Anilina , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Ionóforos de Cálcio/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Corantes Fluorescentes , Técnicas de Silenciamento de Genes , Células HeLa , Compostos Heterocíclicos com 3 Anéis , Humanos , Ionomicina/farmacologia , Mitocôndrias/efeitos dos fármacos , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Xantenos
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