RESUMO
The primary objective of this study was to fabricate a TiO2 nanotubular surface, which could maintain hydrophilicity over time (resist aging). In order to achieve non-aging hydrophilic surfaces, anodization and annealing conditions were optimized. This is the first study to show that anodization and annealing condition affect the stability of surface hydrophilicity. Our results indicate that maintenance of hydrophilicity of the obtained TiO2 nanotubes was affected by anodization voltage and annealing temperature. Annealing sharply decreased the water contact angle (WCA) of the as-synthesized TiO2 nanotubular surface, which was correlated to improved hydrophilicity. TiO2 nanotubular surfaces are transformed to hydrophilic surfaces after annealing, regardless of annealing and anodization conditions; however, WCA measurements during aging demonstrate that surface hydrophilicity of non-anodized and 20 V anodized samples decreased after only 11 days of aging, while the 60 V anodized samples maintained their hydrophilicity over the same time period. The nanotubes obtained by 60 V anodization followed by 600 °C annealing maintained their hydrophilicity significantly longer than nanotubes which were obtained by 60 V anodization followed by 300 °C annealing.
Assuntos
Ligas/química , Materiais Biocompatíveis/química , Nanotubos/química , Titânio/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Temperatura Alta , Interações Hidrofóbicas e Hidrofílicas , Interferometria/métodos , Microscopia Eletrônica de Varredura/métodos , Nanotubos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Fatores de Tempo , Água/químicaRESUMO
Emerging and reemerging human viral pathogens pose great public health concerns since therapeutics against these viruses are limited. Thus, there is an urgent need to develop novel drugs that can block infection of either a specific virus or a number of viruses. Viral entry is thought to be an ideal target for potential therapeutic prevention. One of the challenges of developing antivirals is that most of these viruses are highly pathogenic and therefore require high biosafety-level containment. In this study, we have adopted a comparative high-throughput screening protocol to identify entry inhibitors for three enveloped viruses (Marburg virus, influenza virus H5N1, and Lassa virus) using a human immunodeficiency virus-based pseudotyping platform. We demonstrate the utility of this approach by screening a small compound library and identifying putative entry inhibitors for these viruses. One major advantage of this protocol is to reduce the number of false positives in hit selection, and we believe that the protocol is useful for inhibitor screening for many enveloped viruses.
Assuntos
Antivirais/farmacologia , Ensaios de Triagem em Larga Escala , Testes de Sensibilidade Microbiana/métodos , Internalização do Vírus/efeitos dos fármacos , Vírus/efeitos dos fármacos , Linhagem Celular , Descoberta de Drogas/métodos , Humanos , Reprodutibilidade dos Testes , Bibliotecas de Moléculas PequenasRESUMO
Latest genotyping solutions allow for rapid testing of more than two million markers in one experiment. Fully automated instruments such as Affymetrix GeneTitan enable processing of large numbers of samples in a truly high-throughput manner. In concert with solutions like Axiom, fully customizable array plates can now utilize automated workflows that can leverage multi-channel instrumentation like the GeneTitan. With the growing size of raw data output, the serial computational architecture of the software, typically distributed by the vendors on turnkey desktop solutions for quality control and genotype calling, becomes legacy rather than an advantage. Advanced software techniques provide power, flexibility, and can be deployed in an HPC environment, but become technically inconvenient for biologists to use. Here we present a pipeline that uses Galaxy as a mechanism to lower the barrier for complex analysis, and increase efficiency by leveraging high-throughput computing.
Assuntos
Infecções por Helicobacter/diagnóstico , Helicobacter/isolamento & purificação , Pessoal de Laboratório , Doenças Profissionais/diagnóstico , Zoonoses/diagnóstico , Adulto , Idoso , Experimentação Animal , Animais , Estudos Transversais , DNA Bacteriano/análise , Fezes/química , Fezes/microbiologia , Feminino , Helicobacter/genética , Infecções por Helicobacter/microbiologia , Humanos , Laboratórios , Masculino , Camundongos , Pessoa de Meia-Idade , Doenças Profissionais/microbiologia , Universidades , Adulto Jovem , Zoonoses/microbiologiaRESUMO
Traditional microscopy methods for the detection and quantification of Cryptosporidium parvum in soil matrices are time-consuming, labor-intensive, and lack sensitivity and specificity. This research focused on developing a qPCR protocol for the sensitive and specific detection and quantification of C. parvum in natural soil matrices and soil-water extracts. The physico-chemical parameters - lysis media, number of thermal shocks and thawing temperatures - controlling DNA extraction efficiency were investigated. Experimental results identified oocyst age as a critical parameter affecting oocyst disruption and quantification. The most efficient oocyst disruption method for C. parvum oocysts regardless of their age was established as 5 thermal shocks with thawing at 65°C in Tris-EDTA (TE) buffer. In addition to the purification columns used to remove PCR inhibitors present in environmental matrices, a combination of 3mM MgCl(2) and 600ng/µl BSA yielded the highest amplicon yield for both young and aged oocysts. Sucrose flotation was determined to be a better oocyst isolation method than two-phase flotation. The optimized parameters for DNA extraction and the qPCR assay resulted in very specific and sensitive detection of C. parvum. Minimum detection limits were 0.667 for young C. parvum oocysts and 6.67 for aged C. parvum oocysts per PCR reaction. The accuracy of the detections and quantifications was 0.999. Protocol performance was tested in contrasting soil samples and soil-water extract samples on the basis of percentage of recovery (PR) values. Depending on the number of oocysts used to inoculate the samples, the average PR values ranged from 7.2 to 43.5%, 29.3-52.5%, and 11.5-60.8% for Trenton, Greenson, and Sparta soil-water extracts, respectively, and 12.1-77% for DI water. PR values ranged from 4.3% to 107.8% for Trenton, Greenson and Sparta soil samples.
Assuntos
Cryptosporidium parvum/isolamento & purificação , Carga Parasitária/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Solo/parasitologia , Sensibilidade e Especificidade , Manejo de Espécimes/métodosRESUMO
With aqueous hypochlorite and a phase transfer catalyst, secondary alcohols undergo hitherto unreported free radical reactions that compete with and effectively limit traditional ketone syntheses. Product mixture profiles are determined by reactant ratios, organic cosolvent, and availability of oxygen to the system. Under argon, over half of substrate alcohols, PhCH(OH)R, are converted to benzaldehyde and free radical products through beta-scission of intermediate alkyl hypochlorites. Secondary alcohols with R containing three or more carbons also may undergo delta chlorination.