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1.
Front Microbiol ; 15: 1404366, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38784792

RESUMO

Introduction: Biliary Infection in patients is a common and important phenomenon resulting in severe complications and high morbidity, while the distributions and drug resistance profiles of biliary bacteria and related risk factors are dynamic. This study explored the characteristics of and risk factors for biliary infection to promote the rational use of antibiotics in clinically. Methods: Bacterial identification and drug susceptibility testing were completed using the Vitek 2 Compact analysis system. The distribution and antibiotic-resistant characteristics of 3,490 strains of biliary bacteria in patients at Nankai Hospital from 2019 to 2021 were analyzed using Whonet 5.6 and SPSS 26.0 software. We then retrospectively analyzed the clinical data and risk factors associated with 2,340 strains of Gram-negative bacilli, which were divided into multidrug-resistant bacteria (1,508 cases) and non-multidrug-resistant bacteria (832 cases) by a multivariate Cox regression model. Results and discussion: A total of 3,490 pathogenic bacterial strains were isolated from bile samples, including 2,340 (67.05%) Gram-negative strains, 1,029 (29.48%) Gram-positive strains, and 109 (4.56%) fungal strains. The top five pathogenic bacteria were Escherichia coli, Klebsiella pneumoniae, Enterococcus faecium, Enterococcus faecalis, and Pseudomonas aeruginosa. The rate of Escherichia coli resistance to ciprofloxacin increased (p < 0.05), while the resistance to amikacin decreased (p < 0.05). The resistance of Klebsiella pneumoniae to cephalosporins, carbapenems, ß-lactamase inhibitors, cephalases, aminoglycosides, and quinolones increased (p < 0.05), and the resistance of Pseudomonas aeruginosa to piperacillin, piperacillin/tazobactam, ticacillin/clavulanic acid, and amicacin declined significantly (p < 0.05). The resistance of Enterococcus faecium to tetracycline increased by year (p < 0.05), and the resistance of Enterococcus faecalis to erythromycin and high-concentration gentamicin declined (p < 0.05). Multivariate logistic regression analysis suggested that the administration of third- or fourth-generation cephalosporins was an independent risk factor for biliary infection. In summary, Gram-negative bacilli were the most common pathogenic bacteria isolated from biliary infection patients, especially Escherichia coli, and the rates and patterns of drug resistance were high and in constant flux; therefore, rational antimicrobial drug use should be carried out considering risk factors.

2.
ACS Nano ; 17(22): 23181-23193, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-37956093

RESUMO

The violent side reactions of Zn metal in aqueous electrolyte lead to sharp local-pH fluctuations at the interface, which accelerate Zn anode breakdown; thus, the development of an optimization strategy to accommodate a wide pH range is particularly critical for improving aqueous Zn metal batteries. Herein, we report a pH-adaptive electric double layer (EDL) tuned by glycine (Gly) additive with pH-dependent ionization, which exhibits excellent capability to stabilize Zn anodes in wide-pH aqueous electrolytes. It is discovered that a Gly-ionic EDL facilitates the directed migration of charge carriers in both mildly acidic and alkaline electrolytes, leading to the successful suppression of local saturation. It is worth mentioning that the regulation effect of the additive concentration on the inner Helmholtz plane (IHP) structure of Zn electrodes is clarified in depth. It is revealed that the Gly additives without dimerization can develop orderly and dense vertical adsorption within the IHP to effectively reduce the EDL repulsive force of Zn2+ and isolate H2O from the anode surface. Consequently, they Zn anode with tunable EDL exhibits superior electrochemical performance in a wide range of pH and temperature, involving the prodigious cycle reversibility of 7000 h at Zn symmetric cells with ZnSO4-Gly electrolytes and an extended lifespan of 50 times in Zn symmetric cells with KOH-Gly electrolytes. Moreover, acidic Zn powder||MnO2 pouch cells, and alkaline high-voltage Zn||Ni0.8Co0.1Mn0.1O2 cells, and Zn||NiCo-LDH cells also deliver excellent cycling reversibility. The tunable EDL enables the ultrahigh depth of discharge (DOD) of 93%. This work elucidates the design of electrolyte additives compatible in a wide range of pH and temperature, which might cause inspiration in the fields of practical multiapplication scenarios for Zn anodes.

3.
Health Inf Sci Syst ; 11(1): 18, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37008895

RESUMO

Chronic metabolic diseases arise from changes in metabolic fluxes through biomolecular pathways and gene networks accumulated over the lifetime of an individual. While clinical and biochemical profiles present just real-time snapshots of the patients' health, efficient computation models of the pathological disturbance of biomolecular processes are required to achieve individualized mechanistic insights into disease progression. Here, we describe the Generalized metabolic flux analysis (GMFA) for addressing this gap. Suitably grouping individual metabolites/fluxes into pools simplifies the analysis of the resulting more coarse-grain network. We also map non-metabolic clinical modalities onto the network with additional edges. Instead of using the time coordinate, the system status (metabolite concentrations and fluxes) is quantified as function of a generalized extent variable (a coordinate in the space of generalized metabolites) that represents the system's coordinate along its evolution path and evaluates the degree of change between any two states on that path. We applied GMFA to analyze Type 2 Diabetes Mellitus (T2DM) patients from two cohorts: EVAS (289 patients from Singapore) and NHANES (517) from the USA. Personalized systems biology models (digital twins) were constructed. We deduced disease dynamics from the individually parameterized metabolic network and predicted the evolution path of the metabolic health state. For each patient, we obtained an individual description of disease dynamics and predict an evolution path of the metabolic health state. Our predictive models achieve an ROC-AUC in the range 0.79-0.95 (sensitivity 80-92%, specificity 62-94%) in identifying phenotypes at the baseline and predicting future development of diabetic retinopathy and cataract progression among T2DM patients within 3 years from the baseline. The GMFA method is a step towards realizing the ultimate goal to develop practical predictive computational models for diagnostics based on systems biology. This tool has potential use in chronic disease management in medical practice. Supplementary Information: The online version contains supplementary material available at 10.1007/s13755-023-00218-x.

4.
Adv Mater ; 35(16): e2211296, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36689736

RESUMO

High-performance all-polymer solar cells (all-PSCs) deeply rely on the joint contributions of desirable optical absorption, adaptive energy levels, and appropriate morphology. Herein, two structural analogous polymerized small-molecule acceptors (PSMAs), PYFCl-T and PYF&PYCl-T, are synthesized, and then incorporated into the PM6:PY-IT binary blends to construct ternary all-PSCs. Due to the superior compatibility of PY-IT and PYFCl-T, the ternary all-PSC based on PM6:PY-IT:PYFCl-T with 10 wt% PYFCl-T, presents higher and more balanced charge mobility, suppressed charge recombination, and faster charge-transfer kinetics, resulting in an outstanding power conversion efficiency (PCE) of 18.12% with enhanced Jsc and FF, which is much higher than that (PCE of 16.09%) of the binary all-PSCs based on PM6:PY-IT. Besides, the ternary all-PSCs also exhibit improved photostability. The conspicuous performance enhancement principally should give the credit to the miscibility-driven phase optimization of the donor and acceptor. These findings highlight the significance of polymer-backbone configuration modulation of PSMAs in morphology optimization toward boosting the device properties of all-PSCs.

5.
Sci Bull (Beijing) ; 67(20): 2096-2102, 2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36546109

RESUMO

Recently, the power conversion efficiencies (PCEs) of all-polymer solar cells (all-PSCs) have increased rapidly. To further increase the PCE of all-PSCs, it is necessary to create new donor polymers matching the polymer acceptors. In this paper, we synthesize a new quinoxaline-based polymer donor PBQ8 with n-octyl side chain on the quinoxaline unit, which possesses the same skeleton structure to the previously reported PBQ5 (with isooctyl side chain). The effects of alkyl side chains on the physicochemical properties of the polymer donor were investigated. In comparison with PBQ5, PBQ8 exhibits stronger intermolecular interactions and better molecular packing. When blending with polymer acceptor PY-IT, the PBQ8:PY-IT based devices demonstrated a higher PCE value of 17.04%, which is one of the highest PCEs occurred in the all-PSCs. And the PBQ5:PY-IT (PCE 15.56%, Voc 0.907 V, FF 69.72%, and Jsc 24.60 mA cm-2) is much lower. The PBQ8:PY-IT blend displayed more efficient exciton dissociation, better molecular stacking properties, preferable phase separation and higher mobility. These indicate that as an effective method, side chain engineering can improve the efficiency of the all-PSCs.

6.
Adv Mater ; 34(11): e2108829, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35048434

RESUMO

Combining the high stability under UV light of the wide bandgap (WBG) perovskite solar cells (pero-SCs) and the broad near-infrared absorption spectra of the narrow bandgap (NBG) organic solar cells (OSCs), the perovskite/organic tandem solar cells (TSCs) with the WBG pero-SC as front cell and the NBG OSC as rear cell have attracted attention . However, the photovoltaic performance of the perovskite/organic TSCs needs to be further improved. Herein, nonradiative charge recombination loss is reduced through bulk defect passivation in the WBG pero-SC front subcell and broadening the range of absorption spectra of the NBG OSC rear cell. For the WBG pero-SCs, an organic cation chloro-formamidinium is introduced into FA0.6 MA0.4 Pb(I0.6 Br0.4 )3 to passivate the bulk defects in the perovskite film and the WBG pero-SC displays high open-circuit voltage of 1.25 V and high fill factor of 83.0%. For the NBG OSCs, a new infrared-absorbing organic small molecule acceptor BTPV-4Cl-eC9 is designed and synthesized. Then, a monolithic perovskite/organic TSC is fabricated with the WBG pero-SC as the front cell and the NBG OSC as the rear cell, and the TSC demonstrates high power conversion efficiency up to 22.0%. The results indicate that the perovskite/organic TSC is promising for future commercialization.

7.
Adv Mater ; 33(23): e2100474, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33914352

RESUMO

Side-chain engineering has been an effective strategy in tuning electronic energy levels, intermolecular interaction, and aggregation morphology of organic photovoltaic materials, which is very important for improving the power conversion efficiency (PCE) of organic solar cells (OSCs). In this work, two D-A copolymers, PBQ5 and PBQ6, are designed and synthesized based on bithienyl-benzodithiophene (BDTT) as the donor (D) unit, difluoroquinoxaline (DFQ) with different side chains as the acceptor (A) unit, and thiophene as the π-bridges. PBQ6 with two alkyl-substituted fluorothiophene side chains on the DFQ units possesses redshifted absorption, stronger intermolecular interaction, and higher hole mobility than PBQ5 with two alkyl side chains on the DFQ units. The blend film of the PBQ6 donor with the Y6 acceptor shows higher and balanced hole/electron mobilities, less charge carrier recombination, and more favorable aggregation morphology. Therefore, the OSC based on PBQ6:Y6 achieves a PCE as high as 17.62% with a high fill factor of 77.91%, which is significantly higher than the PCE (15.55%) of the PBQ5:Y6-based OSC. The PCE of 17.62% is by far one of the highest efficiencies for the binary OSCs with polymer donor and Y6 acceptor.

8.
Nat Commun ; 12(1): 178, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33420010

RESUMO

Tandem organic solar cells are based on the device structure monolithically connecting two solar cells to broaden overall absorption spectrum and utilize the photon energy more efficiently. Herein, we demonstrate a simple strategy of inserting a double bond between the central core and end groups of the small molecule acceptor Y6 to extend its conjugation length and absorption range. As a result, a new narrow bandgap acceptor BTPV-4F was synthesized with an optical bandgap of 1.21 eV. The single-junction devices based on BTPV-4F as acceptor achieved a power conversion efficiency of over 13.4% with a high short-circuit current density of 28.9 mA cm-2. With adopting BTPV-4F as the rear cell acceptor material, the resulting tandem devices reached a high power conversion efficiency of over 16.4% with good photostability. The results indicate that BTPV-4F is an efficient infrared-absorbing narrow bandgap acceptor and has great potential to be applied into tandem organic solar cells.

9.
Angew Chem Int Ed Engl ; 59(48): 21683-21692, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-32815586

RESUMO

A record power conversion efficiency of 8.40 % was obtained in single-component organic solar cells (SCOSCs) based on double-cable conjugated polymers. This is realized based on exciton separation playing the same role as charge transport in SCOSCs. Two double-cable conjugated polymers were designed with almost identical conjugated backbones and electron-withdrawing side units, but extra Cl atoms had different positions on the conjugated backbones. When Cl atoms were positioned at the main chains, the polymer formed the twist backbones, enabling better miscibility with the naphthalene diimide side units. This improves the interface contact between conjugated backbones and side units, resulting in efficient conversion of excitons into free charges. These findings reveal the importance of charge generation process in SCOSCs and suggest a strategy to improve this process: controlling miscibility between conjugated backbones and aromatic side units in double-cable conjugated polymers.

10.
Macromol Rapid Commun ; 39(14): e1700611, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29171694

RESUMO

Two conjugated polymers based on diketopyrrolopyrrole (DPP) in the main chain with different content of perylene bisimide (PBI) side chains are developed. The influence of PBI side chain on the photovoltaic performance of these DPP-based conjugated polymers is systematically investigated. This study suggests that the PBI side chains can not only alter the absorption spectrum and energy level but also enhance the crystallinity of conjugated polymers. As a result, such polymers can act as electron donor, electron acceptor, and single-component active layer in organic solar cells. These findings provide a new guideline for the future molecular design of multifunctional conjugated polymers.


Assuntos
Imidas/química , Perileno/análogos & derivados , Polímeros/química , Pirróis/química , Energia Solar , Fontes de Energia Elétrica , Transporte de Elétrons , Estrutura Molecular , Perileno/química , Luz Solar
11.
Sci Rep ; 7: 43691, 2017 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-28252002

RESUMO

Post-translational modifications of viral proteins play important roles in regulating viral replication. Here we demonstrated that the PB2 of influenza A virus (IAV) can be modified by NEDD8. We revealed that E3 ligase HDM2 can promote PB2 NEDDylation. Overexpression of either NEDD8 or HDM2 can inhibit IAV replication, while knockdown of HDM2 has the opposite effect. Then we identified residue K699 in PB2 as the major NEDDylation site. We found that NEDDylation deficient PB2 mutant (PB2 K699R) has a longer half-life than wild-type PB2, indicating that NEDDylation of PB2 reduces its stability. We generated an IAV mutant in which PB2 was mutated to PB2 K699R (WSN-PB2 K699R) and examined the replication of WSN and WSN-PB2 K699R viruses in both MDCK and A549 cells and found that the replication of WSN-PB2 K699R was more efficient than wild-type WSN. In addition, we observed that overexpression of NEDD8 significantly inhibited the replication of WSN, but not WSN-PB2 K699R. The infection assay in mice showed that WSN-PB2 K699R exhibited enhanced virulence in mice compared to WSN, suggesting that NEDDylation of PB2 reduced IAV replication in vivo. In conclusion, we demonstrated that NEDDylation of PB2 by HDM2 negatively regulates IAV infection.


Assuntos
Vírus da Influenza A/fisiologia , Proteínas Virais/metabolismo , Replicação Viral , Animais , Linhagem Celular , Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Humana/genética , Influenza Humana/metabolismo , Influenza Humana/virologia , Proteína NEDD8/genética , Proteína NEDD8/metabolismo , Ligação Proteica , Processamento de Proteína Pós-Traducional , Estabilidade Proteica , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Recombinação Genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Virais/genética , Virulência/genética
12.
J Gen Virol ; 97(1): 27-38, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26498766

RESUMO

In order to explore the roles of microRNA(s) [miRNA(s)] in the influenza A virus life cycle, we compared the miRNA profiles of 293T and HeLa cell lines, as influenza A virus can replicate efficiently in 293T cells but only poorly in HeLa cells. We analysed differentially expressed miRNAs and identified five, including miR-33a, that could disturb influenza A virus replication significantly. Using TargetScan analysis, we found that ARCN1 could be a potential target of miR-33a. To confirm whether miR-33a could truly target ARCN1, we generated a luciferase reporter for the ARCN1 3' untranslated region (UTR) and performed a luciferase assay. The data indicated that miR-33a could suppress the luciferase activity of the reporter for the ARCN1 3' UTR but not a reporter in which the predicted miR-33a targeting sites on ARCN1 3' UTR were mutated. We performed immunoblotting to confirm that miR-33a could downregulate the protein level of ARCN1. Consistently, the level of ARCN1 protein in HeLa cells was significantly lower than that in 293T cells. We also demonstrated that ectopic expression of ARCN1 could partially rescue the inhibitory effect of miR-33a on virus replication. Furthermore, we demonstrated that miR-33a could impede virus replication at the stage of virus internalization, which was similar to the pattern for knockdown of ARCN1, indicating that miR-33a inhibits influenza virus infection by suppressing ARCN1 expression. In addition, we found that miR-33a could also weaken the viral ribonucleoprotein activity in an ARCN1-independent manner. In conclusion, we found that miR-33a is a novel inhibitory factor for influenza A virus replication.


Assuntos
Proteína Coatomer/antagonistas & inibidores , Interações Hospedeiro-Patógeno , Vírus da Influenza A/imunologia , Vírus da Influenza A/fisiologia , MicroRNAs/metabolismo , Ribonucleoproteínas/antagonistas & inibidores , Internalização do Vírus , Fusão Gênica Artificial , Linhagem Celular , Perfilação da Expressão Gênica , Genes Reporter , Humanos , Immunoblotting , Luciferases/análise , Luciferases/genética
13.
PLoS One ; 8(8): e72289, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23977272

RESUMO

Polo-like kinase 1 (Plk1) is a highly conserved Ser/Thr kinase in eukaryotes and plays a critical role in various aspects of the cell cycle. Plk1 exerts its multiple functions by phosphorylating its substrates. In this study, we found that Plk1 can interact with cyclin T1/Cdk9 complex-the main form of the positive transcription elongation complex b (P-TEFb), and its C-terminal polo-box domain is responsible for the binding. Further analysis indicated that Plk1 could phosphorylate cyclin T1 at Ser564 and inhibit the kinase activity of cyclin T1/Cdk9 complex on phosphorylation of the C-terminal domain (CTD) of RNA polymerase II. By taking the approach of luciferase assay, we demonstrated that over-expression of both wild type Plk1 and constitutively active form of Plk1 inhibits the P-TEFb dependent HIV-1 LTR transcription, while knockdown of Plk1 increases the HIV-1 LTR transcription. Consistently, the data from the HIV-1 pseudovirus reporter assay indicated that Plk1 blocks the gene expression of HIV-1 pseudovirus. Taken together, our results revealed that Plk1 negatively regulates the RNA polymerase II-dependent transcription through inhibiting the activity of cyclin T1/Cdk9 complex.


Assuntos
Proteínas de Ciclo Celular/genética , HIV-1/genética , Fator B de Elongação Transcricional Positiva/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , RNA Polimerase II/genética , Transcrição Gênica , Animais , Ciclo Celular/genética , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Ciclina T/genética , Ciclina T/metabolismo , Quinase 9 Dependente de Ciclina/genética , Quinase 9 Dependente de Ciclina/metabolismo , Regulação da Expressão Gênica , Genes Reporter , HIV-1/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Luciferases/genética , Luciferases/metabolismo , Camundongos , Células NIH 3T3 , Fator B de Elongação Transcricional Positiva/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/metabolismo , RNA Polimerase II/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Vírus Reordenados/genética , Vírus Reordenados/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Vesiculovirus/genética , Vesiculovirus/metabolismo , Quinase 1 Polo-Like
14.
Wei Sheng Wu Xue Bao ; 53(12): 1334-9, 2013 Dec 04.
Artigo em Chinês | MEDLINE | ID: mdl-24697106

RESUMO

OBJECTIVE: To screen for compounds against influenza A virus by using the viral promoter reporter cell line HeLa-IAV-Luc and investigate their anti-viral mechanism. METHODS: We screened the inhibitors of influenza A virus by infecting HeLa-IAV-Luc cells with influenza A virus WSN/H1N1 and treating it with the compounds isolated from microbial metabolites. The cell lysates were then subjected to the luciferase assay. We conducted the pesudovirus assay to analyze whether the compound affected the function of hemagglutinin (HA). We carried out the influenza viral promoter reporter assay to examine whether the compound could inhibitinfluenza viral RNA polymerase (vRNP) activity. The effect of anti-viral compoundon influenza viral RNA synthesis was measured by real-time fluorescence quantitative PCR. RESULTS: Colletodiol inhibited the replication of influenza A virus in HeLa-IAV-Luc cells by luciferase assay. It did not inhibit the function of HA protein based on the results of the time-of-addition experiment and pseudovirus assay. The influenza viral polymerase promoter reporter assay indicated that Colletodiol could inhibit the activity of vRNP dramatically. Due to the inhibition of vRNP, the influenza viral RNA synthesis decreased significantly. CONCLUSION: Compound Colletodiol was an inhibitor of influenza A virus. It blocks the replication of influenza A virus by reducing the activity of vRNP.


Assuntos
Antivirais/farmacologia , RNA Polimerases Dirigidas por DNA/metabolismo , Inibidores Enzimáticos/farmacologia , Vírus da Influenza A Subtipo H1N1/enzimologia , Influenza Humana/virologia , Lactonas/farmacologia , Replicação Viral/efeitos dos fármacos , RNA Polimerases Dirigidas por DNA/antagonistas & inibidores , RNA Polimerases Dirigidas por DNA/genética , Células HeLa , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/fisiologia
15.
Fa Yi Xue Za Zhi ; 26(4): 257-9, 2010 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-20967950

RESUMO

OBJECTIVE: Using microbeam X-ray fluorescence (Micro-XRF) analyzer for determination of acid-resistant silicic particles in lung, and to explore its potential application in diagnosis of drowning. METHODS: Thirty two white rabbits were divided randomly into drowning group (n=12), post-mortem immersion group (n=10) and control group (n=10). Lungs and water sample were collected for determination of area concentration of acid-resistant silicic particles using Micro-XRF method. RESULTS: The area concentration of acid-resistant silicic particles for the drowning water sample was 4.4 mm2/mL. For the lungs of drowning group, the post-mortem immersion group and the control group, the determined average values were (25.30 +/- 10.95) mm2/g, (1.68 +/- 0.63) mm2/g and (1.65 +/- 0.85) mm2/g, respectively, with a statistically significant difference between the drowning group and the other two groups. CONCLUSION: The area concentration of acid-resistant silicic particles in lungs may be used as an indicator of drowning. The method is highly sensitive and rapid. It provides a potential application in drowning diagnosis.


Assuntos
Afogamento/diagnóstico , Água Doce/análise , Pulmão/química , Silício/análise , Espectrometria por Raios X/métodos , Animais , Feminino , Fluorescência , Patologia Legal/métodos , Masculino , Coelhos , Espectrometria por Raios X/instrumentação
16.
J Chromatogr A ; 1141(2): 226-34, 2007 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-17184786

RESUMO

Separation of negatively charged molecules, such as plasmid DNA (pDNA), RNA and endotoxin forms a bottleneck for the development of pDNA vaccine production process. The use of affinity interactions of transition metal ions with these molecules may provide an ideal separation methodology. In this study, the binding behaviour of pDNA, RNA and endotoxin to transition metal ions, either in immobilised or free form, was investigated. Transition metal ions: Cu2+, Ni2+, Zn2+, Co2+ and Fe3+, typically employed in the immobilised metal affinity chromatography (IMAC), showed very different binding behaviour depending on the type of metal ions and their existing state, i.e. immobilised or free. In the alkaline cell lysate, pDNA showed no binding to any of the IMAC chemistries tested whereas RNA interacted significantly with Cu2+-iminodiacetic acid (IDA) and Ni2+-IDA but showed no substantial binding to the rest of the IMAC chemistries. pDNA and RNA, however, interacted to varying degrees with free metal ions in the solution. The greatest selectivity in terms of pDNA and RNA separation was achieved with Zn2+ which enabled almost full precipitation of RNA while keeping pDNA soluble. For both immobilised and free metal ions, ionic strength of solution affected the metal ion-nucleic acid interaction significantly. Endotoxin, being more flexible, was able to interact better with the immobilised metal ions than the nucleic acids and showed binding to all the IMAC chemistries. The specific interactions of immobilised and/or free metal ions with pDNA, RNA and endotoxin showed a good potential, by selectively removing RNA and endotoxin at high efficiency, to develop a simplified pDNA purification process with improved process economics.


Assuntos
DNA/química , Endotoxinas/química , Metais/química , Plasmídeos , RNA/química , Concentração Osmolar , Solubilidade
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