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1.
Geophys Res Lett ; 48(11): e2021GL092700, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34219832

RESUMO

A sequence of discrete solar wind structures within the sheath region of an interplanetary coronal mass ejection on November 6, 2015, caused a series of compressions and releases of the dayside magnetosphere. Each compression resulted in a brief adiabatic enhancement of ions (electrons) driving bursts of electromagnetic ion cyclotron (EMIC; whistler mode chorus) wave growth across the dayside magnetosphere. Fine-structured rising tones were observed in the EMIC wave bursts, resulting in nonlinear scattering of relativistic electrons in the outer radiation belt. Multipoint observations allow us to study the spatial structure and evolution of these sheath structures as they propagate Earthward from L1 as well as the spatio-temporal characteristics of the magnetospheric response. This event highlights the importance of fine-scale solar wind structure, in particular within complex sheath regions, in driving dayside phenomena within the inner magnetosphere.

2.
Nature ; 515(7528): 531-4, 2014 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-25428500

RESUMO

Early observations indicated that the Earth's Van Allen radiation belts could be separated into an inner zone dominated by high-energy protons and an outer zone dominated by high-energy electrons. Subsequent studies showed that electrons of moderate energy (less than about one megaelectronvolt) often populate both zones, with a deep 'slot' region largely devoid of particles between them. There is a region of dense cold plasma around the Earth known as the plasmasphere, the outer boundary of which is called the plasmapause. The two-belt radiation structure was explained as arising from strong electron interactions with plasmaspheric hiss just inside the plasmapause boundary, with the inner edge of the outer radiation zone corresponding to the minimum plasmapause location. Recent observations have revealed unexpected radiation belt morphology, especially at ultrarelativistic kinetic energies (more than five megaelectronvolts). Here we analyse an extended data set that reveals an exceedingly sharp inner boundary for the ultrarelativistic electrons. Additional, concurrently measured data reveal that this barrier to inward electron radial transport does not arise because of a physical boundary within the Earth's intrinsic magnetic field, and that inward radial diffusion is unlikely to be inhibited by scattering by electromagnetic transmitter wave fields. Rather, we suggest that exceptionally slow natural inward radial diffusion combined with weak, but persistent, wave-particle pitch angle scattering deep inside the Earth's plasmasphere can combine to create an almost impenetrable barrier through which the most energetic Van Allen belt electrons cannot migrate.

3.
Ann Dermatol Venereol ; 147(12): 857-861, 2020 Dec.
Artigo em Francês | MEDLINE | ID: mdl-32654792

RESUMO

INTRODUCTION: Hand, foot and mouth disease (HFMD) is form of viral dermatosis well known among the pediatric population, in whom it has a typical presentation. However, it is less common in adults, with a more heterogeneous presentation, potentially making diagnosis extremely challenging for the clinician. PATIENTS AND METHODS: This was a retrospective case series from 2013 to 2018 of HFMD in adults, with all cases being confirmed by cutaneous polymerase chain reaction (PCR). We studied the clinical, epidemiological and viral characteristics of each patient. RESULTS: This series of 6 cases comprised 4 men and 2 women, with a mean age of 42.5 years. Five patients presented extended purpuric lesions, four had bullous lesions, and three showed cutaneous signs without any mucosal lesions. Extended lesions on the trunk were found in four patients. One patient presented rosette-shaped pustular lesions on the limbs, one had eczema-like lesions on the scalp, and one presented extended purpuric lesions on the soles. DISCUSSION: These different cases of adult HFMD raise questions about differential diagnosis in relation to other acute cutaneous and mucous diseases. It is essential to be aware of these different types of presentation of the disease in order to determine the diagnosis and discuss preventive measures.


Assuntos
Exantema , Doença de Mão, Pé e Boca , Adulto , Criança , China , Feminino , Doença de Mão, Pé e Boca/diagnóstico , Doença de Mão, Pé e Boca/epidemiologia , Humanos , Lactente , Masculino , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Pele
4.
Ann Dermatol Venereol ; 145(1): 43-47, 2018 Jan.
Artigo em Francês | MEDLINE | ID: mdl-28780055

RESUMO

INTRODUCTION: Renbök phenomenon describes the inhibition of a lesion when a different one appears. We describe the first case of Renbök phenomenon occurring in a context of erythema migrans (EM) spared by an amoxicillin-induced skin rash and we also present a literature review. CASE REPORT: A 60-year-old patient was treated with amoxicillin for EM on the right knee and subsequently developed generalized erythema as a result of an antibiotic-induced skin rash, with sparing of the area previously affected by EM. Renbök phenomenon was diagnosed. DISCUSSION: In 1981, Cochran et al. first described a maculopapular drug reaction, which spared the sites of previous X irradiation for a tumor. Since then, nearly 40 cases have been reported, mostly describing patient with alopecia areata of the scalp with hair growth within plaques of psoriasis. One of the mechanisms suggested is a role played by cytokine cross-regulation in competition among distinct immune responses. CONCLUSION: We report the first case of Renbök phenomenon involving EM spared by a drug reaction. This phenomenon provides an insight into inflammatory response competition within a single patient.


Assuntos
Amoxicilina/efeitos adversos , Antibacterianos/efeitos adversos , Toxidermias/patologia , Eritema Migrans Crônico/patologia , Amoxicilina/uso terapêutico , Antibacterianos/uso terapêutico , Doxiciclina/uso terapêutico , Toxidermias/etiologia , Substituição de Medicamentos , Eritema Migrans Crônico/tratamento farmacológico , Feminino , Humanos , Joelho , Pessoa de Meia-Idade
7.
Methods ; 64(3): 241-9, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24080420

RESUMO

At present, 33 blood groups representing over 300 antigens are listed by the International Society of Blood Transfusion (ISBT). Most of them result from a single nucleotide polymorphism (SNP) in the corresponding DNA sequence, i.e. approx. 200 SNPs. In immunohematology laboratories, blood group determination is classically carried out by serological tests, but these have some limitations, mostly in term of multiplexing and throughput. Yet, there is a growing need of extended blood group typing to prevent alloimmunization in transfused patients and transfusion accidents. The knowledge of the molecular bases of blood groups allows the use of molecular biology methods within immunohematology laboratories. Numerous assays focused on blood group genotyping were developed and described during the last 10 years. Some of them were real biochips or biosensors while others were more characterized by the particular molecular biology techniques they used, but all were intending to produce multiplex analysis. PCR techniques are most of the time used followed by an analytical step involving a DNA biosensor, biochip or analysis system (capillary electrophoresis, mass spectrometry). According to the method used, the test can then be classified as low-, medium- or high-throughput. There are several companies which developed platforms dedicated to blood group genotyping able to analyze simultaneously various SNPs or variants associated with blood group systems. This review summarizes the characteristics of each molecular biology method and medium-/high-throughput platforms dedicated to the blood group genotyping.


Assuntos
Técnicas Biossensoriais , Tipagem e Reações Cruzadas Sanguíneas , Antígenos de Grupos Sanguíneos/genética , Genótipo , Técnicas de Genotipagem , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase , Polimorfismo Genético , Análise de Sequência de DNA
8.
Biosens Bioelectron ; 241: 115689, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37716158

RESUMO

The onsite detection of glyphosate requires an easy-to-handle, low-cost and disposable assay for untrained users as requested by the ASSURED guidelines. A new strategy based on the expression of fusion proteins is proposed here. A glyphosate oxidase derived from Bacillus subtilis and the 6E10 variant of the dye peroxidase from Pseudomonas putida, both fused with the carbohydrate binding module (CBM) 3a from Clostridium thermocellum, were designed and expressed, leading to GlyphOx-CBM and 6E10-CBM. Cell lysates were used to immobilise both enzymes on cotton buds' heads without any purification. The cotton buds exhibit glyphosate oxidase activity when dipped into a glyphosate-contaminated water sample containing the 6E10-CBM chromogenic substrates. The chromophore could be quantified both in the solution and on the cotton buds' heads. Photography followed by image analysis allows to detect glyphosate with a linear range of 0.25-2.5 mM and a limit of detection (LoD) of 0.12 mM. When the chromogenic substrates are replaced by luminol, the chemiluminescence reaction allows the detection of glyphosate with a linear range of 2-500 µM and a LoD of 0.45 µM. No interference was observed using glyphosate analogues (glycine, sarcosine, aminomethylphosphonic acid) or other herbicides used in a mixture. Only cysteine was found to inhibit 6E10-CBM. Two river waters spiked with glyphosate lead to recoveries of 64-131%. This work describes a very easy-to-handle and inexpensive signal-on bioassay for glyphosate detection in real surface water samples.

9.
Analyst ; 136(14): 2918-24, 2011 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-21666912

RESUMO

TAAs (tumor-associated antigens) microarrays were designed to detect auto-antibodies directly in patient sera. Twelve different probes were chosen according to their described occurrence in cancer pathologies (Cyclin B1, Cyclin D1, Complement factor H, c-myc, IMP1, p53, p62, survivin, Her2/neu, Koc, NY-ESO-1 and PSA). Microarrays of these 12 proteins were immobilized within the nitrocellulose/cellulose acetate membrane of a 96-well filtering microtiter plate bottom. The captured auto-antibodies were detected using a staining approach based on alkaline phosphatase labeling. Thus, the presence of specific auto-antibodies in samples was visualized through the positive staining of the corresponding TAA spots. The TAA HiFi microarrays were shown to be able to capture specific purified anti-TAA antibodies. In real samples, 9 proteins from the 12 TAAs panel were shown to generate specific signal and 5 antigens (p53, NY-ESO-1, IMP1, cyclin B1 and c-myc) were shown to have interaction with more than 10% of the positive sera from cancer patients. This protein subpanel was proven to be able to detect 72.2% of the cancer patients tested (within a 34 panel of 18 patients and 16 healthy donors).


Assuntos
Antígenos de Neoplasias/imunologia , Autoanticorpos/análise , Imunoensaio/métodos , Fosfatase Alcalina/química , Fosfatase Alcalina/metabolismo , Antígenos de Neoplasias/sangue , Autoanticorpos/imunologia , Humanos , Análise Serial de Proteínas/instrumentação , Análise Serial de Proteínas/métodos
10.
Epidemiol Infect ; 139(4): 599-605, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20546637

RESUMO

Understanding local perceptions of disease causation could help public health officials improve strategies to prevent bloody diarrhoea. A cross-sectional survey was conducted in Dhaka, Bangladesh to elicit community beliefs about the causes of and prevention strategies for bloody diarrhoea. Between March and June 2003, we interviewed 541 randomly selected respondents. Overall, 507 (93%) respondents perceived that a vaccine could prevent bloody diarrhoea. If a vaccine provided lifetime protection, 445 (83%) respondents stated that they would opt to get the vaccine and would pay a median of $0·05 (range U.S.$0·01-0·15) for it, equivalent to <1% of their median weekly income. There was almost universal perception that an effective vaccine to prevent bloody diarrhoea was highly beneficial and acceptable. While respondents valued a vaccine for prevention of bloody diarrhoea, they were only willing to pay minimally for it. Therefore, achieving a high rate of Shigella vaccine coverage may require subsidy of vaccine purchase.


Assuntos
Disenteria Bacilar/epidemiologia , Disenteria Bacilar/prevenção & controle , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Vacinas contra Shigella/imunologia , Vacinação/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bangladesh/epidemiologia , Estudos Transversais , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Áreas de Pobreza , Vacinas contra Shigella/economia , Vacinação/economia , Adulto Jovem
11.
Rev Med Interne ; 41(4): 275-278, 2020 Apr.
Artigo em Francês | MEDLINE | ID: mdl-32089328

RESUMO

INTRODUCTION: Clinical presentation of cholesterol crystal embolism (CCE) can be dermatologic when cholesterol crystals become lodged in small cutaneous arteries resulting in ischemia. We report a case of CCE with erythroderma misleading to a diagnostic of drug reaction with eosinophilia and systemic symptoms (DRESS). CASE REPORT: A 66 year-old woman presented with erythroderma few months after initiation of allopurinol. Acute renal failure was present with elevation in plasma creatinine concentration (523µmol/L) and hypereosinophilia (HE) (5666/mm3). Finally, the REGISCAR score helped to rule out DRESS diagnostic. Past blood-count tests were analyzed revealing chronic HE present before allopurinol initiation. Renal biopsy identified CCE. CONCLUSION: This case is the first to report a DRESS like presentation of CCE. Clinical findings are secondary to HE and not to occlusion of cutaneous arteries.


Assuntos
Síndrome de Hipersensibilidade a Medicamentos/diagnóstico , Embolia de Colesterol/diagnóstico , Idoso , Colesterol/química , Colesterol/metabolismo , Cristalização , Diagnóstico Diferencial , Embolia de Colesterol/complicações , Eosinofilia/diagnóstico , Eosinofilia/etiologia , Exantema/diagnóstico , Exantema/etiologia , Feminino , Humanos
12.
J Geophys Res Space Phys ; 125(12): e2020JA028462, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33520562

RESUMO

Curtain precipitation is a recently discovered stationary, persistent, and latitudinally narrow electron precipitation phenomenon in low Earth orbit. Curtains are observed over consecutive passes of the dual AeroCube-6 CubeSats while their in-track lag varied from a fraction of a second to 65 s, with dosimeters that are sensitive to >35-keV electrons. This study uses the AeroCube-6 mission to quantify the statistical properties of 1,634 curtains observed over 3 years. We found that many curtains are narrower than 10 km in the latitudinal direction with 90% narrower than 20 km. We examined the geographic, magnetic local time, and geomagnetic dependence of curtains. We found that curtains are observed in the late-morning and premidnight magnetic local times, with a higher occurrence rate at premidnight, and curtains are observed more often during times of enhanced Auroral Electrojet. We found a few curtains in the bounce loss cone region above the North Atlantic, whose electrons were continuously scattered for at least 6 s. Such observations suggest that continuous curtain precipitation may be a significant loss of >35-keV electrons from the magnetosphere into the atmosphere. We hypothesize that the curtains observed in the bounce loss cone were accelerated by parallel electric fields, and we show that this mechanism is consistent with the observations.

13.
Science ; 217(4564): 1033-4, 1982 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-17839340

RESUMO

The structure of liquid water is described by three atom pair distribution functions gOO(r), gOH(r), and gHH(r). These functions have now been derived from neutron diffraction data on four mixtures of light and heavy water. They will provide a crucial and sensitive test for proposed models of liquid water.

14.
Anal Bioanal Chem ; 393(4): 1191-8, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19030847

RESUMO

A screen-printed (SP) microarray is presented as a platform for the achievement of multiparametric biochips. The SP platform is composed of eight (0.28-mm(2)) working electrodes modified with electroaddressed protein A-aryl diazonium adducts. The electrode surfaces are then used as an affinity immobilisation support for the orientated binding of capture monoclonal antibodies, having specificity against four different point-of-care related proteins (myoglobin, cardiac troponin I, C-reactive protein and brain natriuretic peptide). The immobilised capture antibodies are involved in sandwich assays of the four proteins together with biotinylated detection antibodies and peroxidase-labelled streptavidin in order to permit a chemiluminescent imaging of the SP platform and a sensitive detection of the assayed proteins. The performances of the system in pure buffered solutions, using a 25-min assay duration, were characterised by dynamic ranges of 0.5-50, 0.1-120, 0.2-20 and 0.67-67 microg/L for C-reactive protein, myoglobin, cardiac troponin I and brain natriuretic peptide, respectively. The four different assays were also validated in spiked 40-times-diluted human sera, using LowCross buffer, and were shown to work simultaneously in this complex medium.


Assuntos
Proteínas/química , Eletrodos , Luminescência , Análise Serial de Proteínas
15.
J Colloid Interface Sci ; 308(2): 337-43, 2007 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-17275017

RESUMO

We report the fabrication of a thin silicon membrane with an array of micrometer and submicrometer pores that acts as a scaffold for suspending a lipid bilayer. We successfully deposited a lipid bilayer by the Langmuir-Blodgett method on a synthetic silicon membrane bearing arrays of pores with sizes of 1000, 650, and 300 nm. Topographic images obtained by AFM showed a suspended lipid film spanning the pores, whatever the pore size. Higher stability of bilayers supported on smaller pores was shown by AFM characterization. These results represent an important first step to creating a biomimetic environment to study cell membrane dynamics and/or in developing a biosensor.


Assuntos
Bicamadas Lipídicas , Mimetismo Molecular , Silício/química , Microscopia de Força Atômica
18.
J Biotechnol ; 124(2): 392-402, 2006 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-16492392

RESUMO

Detection of toxic substances interfering with endocrine system is one of the major preoccupations of the European community. A whole-cell bioassay for pollution detection based on stress induction has been designed. Well characterized toxicants, cadmium chloride and thiram (a dithiocarbamate fungicide), were used to optimize the detection conditions such as time-course conditions, cell line and reporter gene to be used. HeLa cells containing the firefly luciferase (luc) reporter gene under the control of the Drosophila melanogaster hsp22 promoter were compared to liver cells (HepG2) containing the same stress gene promoter fused either to the luc or the EGFP (Enhanced-Green Fluorescent Protein) gene. The sensitivity of the obtained bioassay was found to be enhanced by the concomitant use of liver cells and EGFP reporter gene. The detection limits of the toxicants were then lowered from 1 to 0.1 microM and from 1 to 0.01 microM for CdCl(2) and thiram, respectively.


Assuntos
Bioensaio/métodos , Cloreto de Cádmio/análise , Poluentes Ambientais/análise , Fungicidas Industriais/análise , Luciferases de Vaga-Lume/metabolismo , Tiram/análise , Cloreto de Cádmio/toxicidade , Proteínas de Drosophila/genética , Poluentes Ambientais/toxicidade , Fungicidas Industriais/toxicidade , Genes Reporter/genética , Proteínas de Fluorescência Verde/genética , Células HeLa/efeitos dos fármacos , Células HeLa/enzimologia , Proteínas de Choque Térmico/genética , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Humanos , Luciferases de Vaga-Lume/genética , Tiram/toxicidade
19.
J Food Prot ; 69(1): 12-6, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16416894

RESUMO

Dense-phase carbon dioxide (CO2) treatments in a continuous flow through system were applied to apple cider to inactivate Escherichia coli (ATCC 4157). A response surface design with factors of the CO2/product ratio (0, 70, and 140 g/kg), temperature (25, 35, and 45 degrees C), and pressure (6.9, 27.6, and 48.3 MPa) were used. E. coli was very sensitive to dense CO2 treatment, with a more than 6-log reduction in treatments containing 70 and 140 g/kg CO2, irrespective of temperature and pressure. The CO2/product ratio was the most important factor affecting inactivation rate of E. coli. No effect of temperature and pressure was detected because of high sensitivity of the cells to dense CO2. Dense CO2 could be an alternative pasteurization treatment for apple cider. Further studies dealing with the organoleptic quality of the product are needed.


Assuntos
Bebidas/microbiologia , Dióxido de Carbono/farmacologia , Qualidade de Produtos para o Consumidor , Escherichia coli/efeitos dos fármacos , Conservação de Alimentos/métodos , Contagem de Colônia Microbiana , Relação Dose-Resposta a Droga , Escherichia coli/crescimento & desenvolvimento , Humanos , Malus/microbiologia , Pressão , Controle de Qualidade , Paladar , Temperatura
20.
Bioelectrochemistry ; 66(1-2): 139-43, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15833714

RESUMO

The electrochemiluminescence (ECL) of a luminol derivate (ABEI) generated both by a carbon electrode and a polypyrrole-coated carbon electrode was examined. It was found that the polypyrrole film (ppy) did not inhibit the ECL. After that, ABEI anchored on a single stranded DNA target (ODNt) has been used for the ECL detection of the hybridization between a complementary single stranded DNA probe (ODNp) covalently linked to a polypyrrole support and the ODNt. The ECL detection has been performed using a DNA sensor having a low surface concentration of ODNp probes, constituted of a polypyrrole copolymer electrosynthesized from a pyrrole-ODNp/pyrrole monomer ratio of 1/20,000.


Assuntos
Luminol/análogos & derivados , Hibridização de Ácido Nucleico/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Eletroquímica/métodos , Eletrodos , Medições Luminescentes/métodos , Luminol/química , Membranas Artificiais , Polímeros , Pirróis
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