The oscillatory behavior observed during the emptying of a vertical cylinder partially filled with water has been studied for large neck-to-bottle diameter ratios, d^{*}. For large apertures (d^{*}>0.8), a Taylor bubble invades the cylinder from the bottom, and its rising speed exhibits periodic oscillations coupled to periodic motions of the free surface limiting the top air buffer initially present in the bottle.
View Article and Find Full Text PDFBackground: Gene expression profiling (GEP) in cells obtained from peripheral blood has shown that this is a very useful approach for biomarker discovery and for studying molecular pathogenesis of prevalent diseases. While there is limited literature available on gene expression markers associated with Chronic Obstructive Pulmonary Disease (COPD), the transcriptomic picture associated with critical respiratory illness in this disease is not known at the present moment.
Findings: By using Agilent microarray chips, we have profiled gene expression signatures in the whole blood of 28 COPD patients hospitalized with different degrees of respiratory compromise.
The development of new diagnostic methods based on molecular biology has led to evidence of the important role of respiratory viruses in chronic obstructive pulmonary disease (COPD) exacerbations. Cytokines and chemokines are recognized as key actors in the pathogenesis of COPD. The objective of this study was to evaluate the association between viral infection and host cytokine responses in 57 COPD patients hospitalized with an acute exacerbation.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
February 2012
We present accurate measurements of the relative motion and deformation of two large bubbles released consecutively in a quiescent liquid confined in a thin-gap cell. Although the second injected bubble was smaller, we observed that, in all cases, it accelerated and caught up with the leading bubble. This acceleration is related to the wake of the leading bubble, which also induces significant changes in the width and curvature of the trailing bubble.
View Article and Find Full Text PDFViruses are strongly associated with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Interferon-inducible protein-10 has been recently described as a biomarker of human rhinovirus infection, but there are no reports on the role of other immune mediators in AECOPD of viral origin. As an attempt to evaluate the differences in the systemic immune mediators profiles between AECOPD patients with presence/absence of viral infection, we measured 27 cytokines, chemokines, and cellular growth factors in the plasma of 40 patients with AECOPD needing of hospitalization by using a Luminex-based assay.
View Article and Find Full Text PDFIntroduction: The purpose of the study was to establish the efficacy of treatment with intravenous cyclophosphamide pulses and oral corticoids in idiopathic pulmonary fibrosis, compared with the standard treatment with corticoids and azathioprine.
Patients And Method: A prospective, non-controlled study with 2 parallel groups. One group received prednisone plus oral azathioprine for 24 months (AZA group).
The synthesis of a series of thirty-eight new modified dinucleotides and dinucleotide conjugate analogues of d-(5')ApC(3') is described. The inhibitory activity of these compounds toward HIV-1 integrase was examined in enzymatic assays using the natural dinucleotide as a reference. Among the compounds, a perylene-dinucleotide conjugate has shown a two micromolar anti-integrase activity due to the presence of both the intercalator and the dinucleotide.
View Article and Find Full Text PDFThe inefficiency of gene modification by homologous recombination can be overcome by the introduction of a double-strand break (DSB) in the target. Engineering the endonucleases needed, however, remains a challenging task that limits widespread application of nuclease-driven gene modification. We report here that conjugates of orthophenanthroline (OP), a DNA cleaving molecule, and triplex-forming oligonucleotides (TFOs), known to bind specific DNA sequences, are synthetic nucleases efficient at stimulating targeted genome modification.
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
June 2008
The dynamics of high Reynolds number-dispersed two-phase flow strongly depends on the wakes generated behind the moving bodies that constitute the dispersed phase. The length of these wakes is considerably reduced compared with those developing behind isolated bodies. In this paper, this wake attenuation is studied from several complementary experimental investigations with the aim of determining how it depends on the body Reynolds number and the volume fraction alpha.
View Article and Find Full Text PDFNucleosides Nucleotides Nucleic Acids
March 2008
We recently reported the design of new fluorescent oligo-2'-deoxyribonucleotides (FODNs) for the detection of terminal mismatches on DNA duplexes in homogeneous assays. We now report the validation of this method in homogeneous assays with other sequences and the feasibility of the detection of terminal mismatches with immobilized FODNs. In all cases studied, the mismatched duplexes were more fluorescent than the perfect ones and results confirmed that the discrimination factor is sequence-dependent.
View Article and Find Full Text PDFThis paper describes the design of terminal-mismatch discriminating fluorescent oligonucleotides (TMDFOs). The method is based on the use of sets of oligo-2'-deoxyribonucleotide probes linked via their 5'-ends, and varying-sized flexible polymethylene chains, to thiazole orange, with the linker being attached to the benzothiazole moiety. The sequence of each set of labelled probes was identical and complementary to the sequence to be analyzed on the single-stranded nucleic acid target except at the interrogation position, located at the 5'-end of the probes in a position adjacent to the attachment site of the label, where each of the four nucleic bases were incorporated.
View Article and Find Full Text PDFTriplex-forming oligonucleotides (TFOs) are powerful tools to interfere sequence-specifically with DNA-associated biological functions. (A/T,G)-containing TFOs are more commonly used in cells than (T,C)-containing TFOs, especially C-rich sequences; indeed the low intracellular stability of the non-covalent pyrimidine triplexes make the latter less active. In this work we studied the possibility to enhance DNA binding of (T,C)-containing TFOs, aiming to reach cellular activities; to this end, we used locked nucleic acid-modified TFOs (TFO/LNAs) in association with 5'-conjugation of an intercalating agent, an acridine derivative.
View Article and Find Full Text PDFWe report here the synthesis and binding studies of oligo-2'-deoxyribonucleotides (ODNs) containing 2'-deoxyuridines, modified at the 5-position by linkers ending with either one or two guanidinium groups. Comparison was made with ODNs containing 2'-deoxyuridines modified at the 5-position with linkers ending with either two or one amino groups. One or two modified 2'-deoxyuridines were incorporated into pyrimidine strands, and their influence on the stability of duplex (with both DNA and RNA targets) and triplex structures was studied.
View Article and Find Full Text PDFDNA binding compounds, such as benzo[e] (BePI) and benzo[g] pyridoindole (BgPI) derivatives, exhibit preferential stabilization of triple helices. We report here the synthesis of a series of pyrimidine triple-helix-forming oligo-2'-deoxyribonucleotides conjugated with these molecules. BePI was coupled to the 5-position of 2'-deoxyuridine via two linkers of different sizes attached to its 11-position and placed at either the 5'-end, inside the sequence, or at both the 5'-end and the internal positions using periodate oxidation of a diol-containing oligonucleotide followed by reductive coupling with amino-linked BePI.
View Article and Find Full Text PDFOne hundred and thirty-three eyes of 103 patients had photorefractive keratectomy with a slit scan mode excimer laser for myopia ranging from -6.00 to -22.00 diopters (D).
View Article and Find Full Text PDFThe aim of the present study was to test the antigenicity of alpha-deoxyribonucleotides in order to develop a new tool for the detection of nucleic acid sequences for use in diagnostic applications. We describe four monoclonal antibodies (Mabs) which recognize alpha-deoxyribonucleotides. Two were raised against a poly(alpha-dT) sequence and specifically recognized the alpha-dT nucleotide.
View Article and Find Full Text PDFThe catalytic domain of an endoglucanase belonging to family A (CelCCA) from an anaerobic bacterium (Clostridium cellulolyticum) has been crystallized in a form suitable for X-ray diffraction analysis. The crystals have been grown in the presence of polyethylene glycol 4000 using the vapour diffusion technique. The crystals, which diffract to 2.
View Article and Find Full Text PDFAn octa-heme cytochrome c3, isolated as a dimeric molecule of about 30 kDa from the anaerobic bacteria Desulfovibro desulfuricans Norway, has been crystallized in a form suitable for atomic resolution X-ray structural investigations. The crystals are trigonal, space group P3(1)21 (or its enantiomorph P3(2)21), with cell dimensions: a = b = 72.9 A c = 62.
View Article and Find Full Text PDFWe have used alpha-oligomers as antisense oligonucleotides complementary to three different sequences of the rabbit beta-globin mRNA: a region adjacent to the cap site, a region spanning the AUG initiation codon or a sequence in the coding region. These alpha-oligonucleotides were synthesized either with a free 5' OH group or linked to an acridine derivative. The effect of these oligonucleotides on mRNA translation was investigated in cell-free extracts and in Xenopus oocytes.
View Article and Find Full Text PDFAn acridine derivative was covalently linked to the 5' end of a homopyrimidine oligonucleotide. Specific binding to a homopurine-homopyrimidine sequence of duplex DNA was demonstrated by spectroscopic studies (absorption and fluorescence) and by "footprinting" experiments with a copper phenanthroline chelate used as an artificial nuclease. A hypochromism and a red shift of the acridine absorption were observed.
View Article and Find Full Text PDFNucleic Acids Res
September 1987
The unnatural oligonucleotide alpha-d(TCTAAAC) was synthesized and was found more resistant towards endonucleases than its beta-analog. 2D-NMR experiments allowed the assignment of all non-exchangeable aromatic and sugar protons except for the overlapping 5' -5" resonances, as well as the exchangeable imino protons of the parallel hybrid duplex alpha-d (TCTAAAC)-beta-d(AGATTTG). NMR studies show that the strength of the association between the alpha-strand and the beta parallel strand is equivalent to that between their anti-parallel complementary beta-analogs beta-d(CAAATCT) and beta-d(AGATTTG).
View Article and Find Full Text PDFAn octathymidylate was synthesized with the alpha anomer of thymidine instead of the naturally occurring beta anomer. This oligonucleotide binds to complementary sequences containing beta-nucleosides. Binding to ribose-containing oligomers and polymers is much stronger than binding to deoxyribose-containing analogs.
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