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1.
BMC Pregnancy Childbirth ; 21(1): 363, 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33957886

RESUMO

BACKGROUND: Two meta-analyses have shown that pregnancy and birth rates are significantly higher after blastocyst transfer than after cleaved embryo transfer. Other studies have revealed that a serum progesterone level > 1.5 ng/ml on the trigger day is responsible for premature luteinization and is associated with a low pregnancy rate. The objectives of this retrospective study were to determine whether blastocyst transfer gave higher pregnancy rates than cleaved embryo transfer at day 3 in both the general and selected IVF/ICSI populations, and whether the serum progesterone level influenced the pregnancy rate. METHOD: We studied IVF/ICSI cycles with GnRH antagonist - FSH/hMG protocols in a general population (n = 1210) and a selected "top cycle" population (n = 677), after blastocyst transfer on day 5 or cleaved embryo transfer on day 3. The selected couples had to meet the following criteria: female age < 35, first or second cycle, and one or two embryos transferred. We recorded predictive factors for pregnancy and calculated the progesterone to oocyte index (POI), the progesterone:estradiol ratio (P:E2 ratio), and the progesterone to follicle (> 14 mm) index (PFI). RESULTS: In the general population, the clinical pregnancy rate was significantly higher after blastocyst transfer (33.3%) than after cleaved embryo transfer (25.3%; p <  0.01); the same was true for the birth rate (32.1 and 22.8%, respectively, p <  0.01). The differences between blastocyst and embryo transfer groups were not significant in the selected population (respectively 35.7% vs. 35.8% for the clinical pregnancy rate, and 33.9 and 34.9% for the birth rate). The serum progesterone levels on the eve of the trigger day and on the day itself were significantly lower in the pregnant women (p <  0.01). We found a serum progesterone threshold of 0.9 ng/ml, as also reported by other researchers. The POI and the PFI appear to have predictive value for cleaved embryos transfers. CONCLUSIONS: Blastocyst transfers were associated with higher clinical pregnancy and birth rates than cleaved embryo transfers in a general population but not in a selected population. The serum progesterone levels on the eve of the trigger day and on the day itself predicted the likelihood of pregnancy.


Assuntos
Blastocisto , Gonadotropina Coriônica/administração & dosagem , Transferência Embrionária , Fertilização in vitro , Progesterona/sangue , Adulto , Feminino , Humanos , Masculino , Indução da Ovulação , Gravidez , Taxa de Gravidez , Estudos Retrospectivos , Injeções de Esperma Intracitoplásmicas , Fatores de Tempo
2.
Rev Neurol (Paris) ; 177(9): 1168-1175, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34274130

RESUMO

BACKGROUND AND PURPOSE: Low socio-economic status of individuals has been reported to be associated with a higher incidence of stroke and influence the diagnosis after revascularization. However, whether it is associated with poorer acute stroke management is less clear. To determine whether social deprivation was associated with a poorer access to reperfusion therapy, either intravenous thrombolysis (IVT) and/or endovascular thrombectomy (EVT) in a population-based cohort. METHODS: Over a 14-month period, all consecutive adult patients admitted to any emergency department or a comprehensive or primary stroke center (CSC/PSC) of the Rhône county with a confirmed ischemic stroke were included. The socioeconomic status of each patient was measured using the European Deprivation Index (EDI). The association between EDI and access to reperfusion therapy was assessed in univariate and multivariate logistic regression analyses. RESULTS: Among the 1226 consecutive IS patients, 316 (25%) were admitted directly in a PSC or CSC, 241 (19.7%) received a reperfusion therapy; 155 IVT alone, 20 EVT alone, and 66 both therapies. Median age was 79 years, 1030 patients had an EDI level of 1 to 4, and 196 an EDI of 5 (the most deprived group). The most deprived patients (EDI level 5) did not have a poorer access to reperfusion therapy compared to all other patients in univariate (OR 1.22, 95%CI [0.85; 1.77]) nor in multivariate analyses (adjOR 0.97, 95%CI [0.57; 1.66]). CONCLUSIONS: We did not find any significant association between socioeconomic deprivation and access to reperfusion therapy. This suggests that the implementation of EVT was not associated with increased access inequities.


Assuntos
Isquemia Encefálica , Procedimentos Endovasculares , Acidente Vascular Cerebral , Adulto , Idoso , Isquemia Encefálica/epidemiologia , Isquemia Encefálica/terapia , Fibrinolíticos , Humanos , Reperfusão , Fatores Socioeconômicos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/terapia , Trombectomia , Terapia Trombolítica , Resultado do Tratamento
3.
Biofouling ; 34(4): 368-377, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29745778

RESUMO

The present study was aimed at designing and optimizing a rotating disk reactor simulating high hydrodynamic shear rates (γ), which are representative of cooling circuits. The characteristics of the hydrodynamic conditions in the reactor and the complex approach used to engineer it are described. A 60 l tank was filled with freshwater containing free-living amoebae (FLA) and bacteria. Adhesion of the bacteria and formation of a biofilm on the stainless steel coupons were observed. FLA were able to establish in these biofilms under γ as high as 85,000 s-1. Several physical mechanisms (convection, diffusion, sedimentation) could explain the accumulation of amoeboid cells on surfaces, but further research is required to fully understand and model the fine mechanisms governing such transport under γ similar to those encountered in the industrial environment. This technological advance may enable research into these topics.


Assuntos
Amoeba/fisiologia , Bactérias , Biofilmes , Fenômenos Fisiológicos Bacterianos , Água Doce , Hidrodinâmica , Locomoção , Aço Inoxidável
4.
Curr Oncol ; 25(1): 32-40, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29507481

RESUMO

BACKGROUND: In 2016, everolimus was approved by Health Canada for the treatment of unresectable, locally advanced or metastatic, well-differentiated, non-functional, neuroendocrine tumours (NET) of gastrointestinal (GI) or lung origin in adult patients with progressive disease. This analysis evaluated the cost-effectiveness of everolimus in this setting from a Canadian societal perspective. METHODS: A partitioned survival model was developed to compare the cost per life-year (LY) gained and cost per quality-adjusted life-year (QALY) gained of everolimus plus best supportive care (BSC) versus BSC alone in patients with advanced or metastatic NET of GI or lung origin. Model health states included stable disease, disease progression, and death. Efficacy inputs were based on the RADIANT-4 trial and utilities were mapped from quality-of-life data retrieved from RADIANT-4. Resource utilization inputs were derived from a Canadian physician survey, while cost inputs were obtained from official reimbursement lists from Ontario and other published sources. Costs and efficacy outcomes were discounted 5% annually over a 10-year time horizon, and sensitivity analyses were conducted to test the robustness of the base case results. RESULTS: Everolimus had an incremental gain of 0.616 QALYs (0.823 LYs) and CA$89,795 resulting in an incremental cost-effectiveness ratio of CA$145,670 per QALY gained (CA$109,166 per LY gained). The probability of cost-effectiveness was 52.1% at a willingness to pay (WTP) threshold of CA$150,000 per QALY. CONCLUSIONS: Results of the probabilistic sensitivity analysis indicate that everolimus has a 52.1% probability of being cost-effective at a WTP threshold of CA$150,000 per QALY gained in Canada.

5.
Eur J Orthop Surg Traumatol ; 28(2): 239-246, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28900737

RESUMO

INTRODUCTION: The SOFCOT symposium (2005) on periprosthetic fractures of the femur (PFFs) highlighted a high rate of dislocation (15.6% at 6 months) after change of prosthesis. So far, no study has ever proved the benefit of dual-mobility articulation during PFFs revisions. We conducted a comparative study on two prospective cohorts in order to (1) assess the influence of systematic acetabular revision in favor of a double mobility on dislocation rate (2) and in order to evaluate the rate of morbidity associated with this extra surgical procedure. HYPOTHESIS: A systematic replacement of the cup in favor of a dual-mobility articulation enables to reduce the dislocation rate in PFFs revisions without increasing morbidity. METHODOLOGY: We compared two prospective multicenter cohorts over a year (2005 and 2015) using the same methodology. Any fracture around hip prosthesis which occurred 3 months at least after surgery was included. Data collection was clinical and radiological on preoperative, intraoperative and 6 months after surgery. The 2015 "bipolar" group (n = 24) included patients who had a bipolar revision (both femoral and dual-mobility articulation). The 2005 "unipolar" group (n = 25) included patients who had only a femoral implant revision. Patients were comparable by age (p = 0.36), sex (p = 0.91), ASA score (p = 0.36), history of prosthetic revision (p = 1.00), Katz score (p = 0.50) and the type of fracture according to the Vancouver classification (p = 0.55). RESULTS: There was a 4% rate of dislocation in the "bipolar group" while there was 21% rate of dislocation in the "unipolar group" (8% of recurrent dislocation) (p = 0.19). The rate of all-cause complications 6 months after surgery was not significantly different (p = 0.07): 12.5% in the 2015 "bipolar" cohort (one dislocation, one non-symptomatic cup migration and one pseudarthrosis of the major trochanter) versus 35% in the "unipolar" cohort (5 dislocations, 1 major trochanter fracture and 1 femur pseudarthrosis, 1 secondary displacement associated with a superficial infection). The surgical revision after 6 months was not significantly different (1/23 or 4% vs. 4/25 or 16%, p = 0.35). CONCLUSION: We confirm the low rate of dislocations after fitting a dual-mobility cup in case of revision of the femoral side in case of periprosthetic femoral fracture, as well as the need for additional cases to be carried out upon further studies to significantly confirm the interest of preventing instability after femoral revision.


Assuntos
Fraturas do Fêmur/cirurgia , Luxação do Quadril/prevenção & controle , Prótese de Quadril , Fraturas Periprotéticas/cirurgia , Reoperação/métodos , Acetábulo/cirurgia , Idoso , Idoso de 80 Anos ou mais , Feminino , Articulação do Quadril/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reoperação/efeitos adversos
6.
Eur J Neurosci ; 46(10): 2629-2637, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28921770

RESUMO

The physiological and behavioural effects of empathy for other's pain have been widely investigated, while the opposite situation, i.e. the influence on one's pain of empathetic feedback from others, remains largely unexplored. Here, we assessed whether and how empathetic and unempathetic comments from observers modulate pain and associated vegetative reactions. In Study 1, conversations between observers of a pain study were recorded by professional actors. Comments were prepared to be perceived as empathetic, unempathetic or neutral, and were validated in 40 subjects. In a subsequent pain experiment (Study 2), changes in subjective pain and heart rate were investigated in 30 naïve participants who could overhear the empathetic or unempathetic conversations pre-recorded in study 1. Subjective pain was significantly attenuated when hearing empathetic comments, as compared to both unempathetic and neutral conditions, while unempathetic comments failed to significantly modulate pain. Heart rate increased when hearing unempathetic remarks and when receiving pain stimuli, but heart acceleration to nociceptive stimulation was not correlated with pain ratings. These results suggest that empathetic feedback from observers has a positive influence on pain appraisal and that this effect may surpass the negative effect of unempathetic remarks. Negative remarks can either trigger feelings of guilt or induce irritation/anger, with antagonistic effects on pain that might explain inter-individual variation. As in basal conditions heart rate and pain perception are positively correlated, their dissociation here suggests that changes in subjective pain were linked to a cognitive bias rather than changes in sensory input.


Assuntos
Empatia , Percepção da Dor , Percepção Social , Adulto , Feminino , Humanos , Masculino , Medição da Dor , Limiar da Dor , Adulto Jovem
7.
J Eur Acad Dermatol Venereol ; 31(7): 1214-1222, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28370444

RESUMO

BACKGROUND: Hereditary angioedema (HAE) due to C1-inhibitor deficiency (C1-INH-HAE) is a rare, potentially fatal, bradykinin-mediated disease. Icatibant is a bradykinin B2 receptor antagonist originally approved in 2008 in the European Union and 2011 in the United States as an acute therapy option for HAE attacks in adults. OBJECTIVE: To compare demographics, disease characteristics and treatment outcomes of icatibant-treated HAE attacks in patients with C1-INH-HAE enrolled in the Icatibant Outcome Survey across six European countries: Austria, France, Germany, Italy, Spain and the UK. METHODS: The Icatibant Outcome Survey [IOS; Shire, Zug, Switzerland (NCT01034969)] is an international observational study monitoring the safety and effectiveness of icatibant. Descriptive, retrospective analyses compared IOS country data derived during July 2009-April 2015. RESULTS: Overall, 481 patients with C1-INH-HAE provided demographic data. A significant difference across countries in age at onset (P = 0.003) and baseline attack frequency (P < 0.001) was found although no significant differences were found with respect to gender (majority female; P = 0.109), age at diagnosis (P = 0.182) or delay in diagnosis (P = 0.059). Icatibant was used to treat 1893 attacks in 325 patients with majority self-administration in all countries. Overall, significant differences (all P < 0.001) were found across countries in time to treatment [median 1.8 h; median range: 0.0 (Germany-Austria) to 4.4 (France) h], time to resolution [median 6.5 h; median range: 3 (Germany-Austria) to 12 (France) h] and attack duration [median 10.5 h; median range: 3.1 (Germany-Austria) to 18.5 (France) h]. CONCLUSION: These data form the first European cross-country comparison of disease characteristics and icatibant use in patients with C1-INH-HAE who are enrolled in IOS. International variation in icatibant practice and treatment outcomes across the six European countries assessed highlight the need to further investigate the range of country-specific parameters driving regional variations in icatibant use.


Assuntos
Angioedemas Hereditários/tratamento farmacológico , Antagonistas de Receptor B2 da Bradicinina/uso terapêutico , Bradicinina/análogos & derivados , Bradicinina/uso terapêutico , Europa (Continente) , Feminino , Humanos , Masculino , Sistema de Registros , Estudos Retrospectivos , Resultado do Tratamento
8.
Andrologia ; 49(10)2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28261842

RESUMO

In the last 10 years, several approaches, including microarrays, have been applied to investigate sperm transcript levels. However, success using microarray profiling is highly dependent of the quality of the RNA obtained. Therefore, the development of methods that deliver highly purified and intact RNA is of utmost importance. The three steps used to achieve this goal, purification of spermatozoa, RNA extraction and evaluation of RNA quality, are reviewed. Following that review and preliminary experiments, we processed sperm samples from seven normozoospermic men with a combination of gradient centrifugation and somatic cell lysis. RNA was extracted using the NucleoSpin RNA XS kit (Macherey-Nagel) and its purity checked using the BioAnalyzer. Hybridisation was done on Agilent SurePrint G3 Human GE 8 × 60K V2 microarrays. We identified 900 transcripts among the 1000 high abundance sperm transcripts reported in the literature. These genes are known to be involved in several biological processes, notably spermatogenesis, transcription regulation, cell growth and differentiation, sperm motility and capacitation, fertilisation, and embryogenesis. Therefore, our methodology is highly suitable for sperm transcriptomic analyses and can be used, notably, to compare mRNA profiles between fertile and infertile males.


Assuntos
Perfilação da Expressão Gênica/métodos , Infertilidade Masculina/metabolismo , RNA/análise , Espermatozoides/metabolismo , Animais , Humanos , Infertilidade Masculina/genética , Masculino
9.
J Gen Virol ; 97(1): 233-245, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26508507

RESUMO

The phosphatidylinositol-3-kinase (PI3K)/Akt/target of rapamycin (TOR) signalling pathway controls cell growth and survival, and is targeted by a number of viruses at different phases of their infection cycle to control translation. Whether and how insect viruses interact with this pathway remain poorly addressed. Here, we investigated the role of PI3K/Akt/TOR signalling during lethal infection of insect cells with an insect parvovirus. Using Junonia coenia densovirus (JcDV; lepidopteran ambidensovirus 1) and susceptible insect cells as experimental models, we first described JcDV cytopathology, and showed that viral infection affects cell size, cell proliferation and survival. We deciphered the role of PI3K/Akt/TOR signalling in the course of infection and found that non-structural (NS) protein expression correlates with the inhibition of TOR and the shutdown of cellular synthesis, concomitant with the burst of viral protein expression. Together, these results suggest that NS proteins control the cellular translational machinery to favour the translation of viral mRNAs at the expense of cellular mRNAs. As a consequence of TOR inhibition, cell autophagy is activated. These results highlight new functions for NS proteins in the course of multiplication of an insect parvovirus.


Assuntos
Densovirus/crescimento & desenvolvimento , Interações Hospedeiro-Patógeno , Insetos/virologia , Proteína Oncogênica v-akt/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Animais , Linhagem Celular , Proliferação de Células , Tamanho Celular , Sobrevivência Celular , Modelos Teóricos , Biossíntese de Proteínas , Proteínas não Estruturais Virais/metabolismo
10.
J Chem Phys ; 143(1): 014201, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-26156476

RESUMO

We have used continuous-wave cavity ring-down and femto-Fourier transform-cavity-enhanced absorption spectrometers to record the spectrum of the OH-stretching + CH-stretching (ν1 + ν2) combination band in trans-formic acid, with origin close to 6507 cm(-1). They, respectively, allowed resolving and simplifying the rotational structure of the band near its origin under jet-cooled conditions (Trot = 10 K) and highlighting the overview of the band under room temperature conditions. The stronger B-type and weaker A-type subbands close to the band origin could be assigned, as well as the main B-type Q branches. The high-resolution analysis was hindered by numerous, severe perturbations. Rotational constants are reported with, however, limited physical meaning. The ν1 + ν2 transition moment is estimated from relative intensities to be 24° away from the principal b-axis of inertia.

11.
Andrologia ; 47(2): 178-85, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24612408

RESUMO

Complex chromosome rearrangements (CCRs) are structural rearrangements involving at least three chromosomes and three or more chromosome breakpoints. Generally, balanced CCR carriers have a normal phenotype but they are at a higher reproductive risk. Azoospermia was discovered in the male partner of a couple with primary infertility. Conventional cytogenetics identified a CCR refined by fluorescent in situ hybridisation. The CCR involved three chromosomes, four breakpoints and an insertion. A literature search identified 43 phenotypically normal males referred for reproductive problems presenting a CCR. More males were ascertained because of spermatogenesis failure or disturbances than because of repeated abortions and/or birth of a malformed child. Male carriers of CCR produce a high frequency of chromosomally abnormal spermatozoa due to the aberrant segregation of the rearranged chromosomes. The number of chromosomes and breakpoints involved in the rearrangement, the position of breakpoints, the relative size of the resultant chromosomes and the presence or absence of recombination inside the paired-rearranged segments are presumed to affect the fertility of the carrier. Testicular biopsy should not be performed in males with azoospermia. Intracytoplasmic sperm injection should not be proposed as a procedure for treating the infertility of CCR male carriers as a successful result is unlikely.


Assuntos
Azoospermia/genética , Pontos de Quebra do Cromossomo , Rearranjo Gênico/genética , Infertilidade Masculina/genética , Adulto , Azoospermia/complicações , Azoospermia/diagnóstico , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 15/genética , Cromossomos Humanos Par 5/genética , Humanos , Infertilidade Masculina/diagnóstico , Infertilidade Masculina/etiologia , Masculino , Mutagênese Insercional/genética , Fenótipo
12.
J Vet Pharmacol Ther ; 38(3): 209-13, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25404261

RESUMO

Many veterinary medications can be lethal in human overdose. This review aims to educate practicing veterinarians about the most common medications used by humans in intentional overdose. Strategies to mitigate the risk posed by these medications are discussed, and the risk factors that predispose a person to suicide are reviewed. Synthesis of the published cases will allow veterinarians to easily identify high-risk medications and to take steps to prevent their misuse by at-risk patients or staff.


Assuntos
Suicídio/estatística & dados numéricos , Drogas Veterinárias , Animais , Humanos , Uso Indevido de Medicamentos sob Prescrição/prevenção & controle , Uso Indevido de Medicamentos sob Prescrição/estatística & dados numéricos , Fatores de Risco , Tentativa de Suicídio/estatística & dados numéricos
13.
Rev Sci Instrum ; 95(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38276899

RESUMO

The correct interpretation of infrared (IR) observations of planetary atmospheres requires an accurate knowledge of temperature and partial and global pressures. Precise laboratory measurements of absorption intensities and line profiles, in the 200-350 K temperature range, are, therefore, critical. However, for gases only existing in complex chemical equilibria, such as nitrous or hypobromous acids, it is not possible to rely on absolute pressure measurements to measure absolute integrated optical absorption cross sections or IR line intensities. To overcome this difficulty, a novel dual-beam terahertz (THz)/mid-IR experimental setup has been developed, relying on the simultaneous use of two instruments. The setup involves a newly constructed temperature-controlled (200-350 K) cross-shaped absorption cell made of inert materials. The cell is traversed by the mid-IR beam from a high-resolution Fourier transform spectrometer using along a White-cell optical configuration providing absorption path lengths from 2.8 to 42 m and by a THz radiation beam (82.5 GHz to 1.1 THz), probing simultaneously the same gaseous sample. The THz channel records pure rotational lines of molecules for which the dipole moment was previously measured with high precision using Stark spectroscopy. This allows for a determination of the partial pressure in the gaseous mixture and enables absolute line intensities to be retrieved for the mid-IR range. This new instrument opens a new possibility for the retrieval of spectroscopic parameters for unstable molecules of atmospheric interest. The design and performance of the equipment are presented and illustrated by an example of simultaneous THz and mid-IR measurement on nitrous acid (HONO) equilibrium.

14.
Science ; 384(6700): 1086-1090, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38843318

RESUMO

Very-low-mass stars (those less than 0.3 solar masses) host orbiting terrestrial planets more frequently than other types of stars. The compositions of those planets are largely unknown but are expected to relate to the protoplanetary disk in which they form. We used James Webb Space Telescope mid-infrared spectroscopy to investigate the chemical composition of the planet-forming disk around ISO-ChaI 147, a 0.11-solar-mass star. The inner disk has a carbon-rich chemistry; we identified emission from 13 carbon-bearing molecules, including ethane and benzene. The high column densities of hydrocarbons indicate that the observations probe deep into the disk. The high carbon-to-oxygen ratio indicates radial transport of material within the disk, which we predict would affect the bulk composition of any planets forming in the disk.

15.
Phys Chem Chem Phys ; 15(15): 5691-700, 2013 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-23474807

RESUMO

Previous experimental and theoretical studies have established that electrokinetic and aggregation properties of soft MS2 phages are not only governed by the physico-chemical features of their proteinaceous outer surface but are also significantly impacted by those of their inner RNA component (Dika et al. Appl. Environ. Microbiol., 2011, 14, 4939-4948). These conclusions contradict the recent findings of Nguyen et al. (Soft Matter, 2011, 7, 10449-10456) who reported identical electrokinetic and aggregation characteristics for MS2 and corresponding virus like particles (VLPs) that lack the internal RNA component. We demonstrate here that this contradiction originates from the different purification methods adopted prior to measurements. More generally, we show that stability and electrohydrodynamics of viruses differ according to purification by (i) dialysis, (ii) isopycnic centrifugation in the cesium chloride gradient, and (iii) precipitation using polyethylene glycol (PEG). Methods (i) and (iii) lead to aggregation of MS2 phages at pH ≤ 4 and pH ≤ 6 in 1-100 mM NaNO3 solutions, respectively, while under such conditions aggregation is not observed for MS2 and VLP suspensions prepared according to (ii). In addition, VLPs prepared following methods (i) and (iii) aggregate only at the isoelectric point (pH ~ 3-4) in 1 mM NaNO3 solution. Electrophoretic mobility data of stable MS2 and VLP particles were further examined using a recent formalism for electrokinetics of soft multilayered colloids. The analysis qualitatively shows how the purification protocol may affect either the outer particle surface properties and/or the inner particle content. Finally, the non-DLVO aggregation behavior of MS2 and VLPs purified via the above protocols is discussed in terms of the possible change in corresponding interparticular interactions.


Assuntos
Levivirus/isolamento & purificação , Centrifugação Isopícnica , Césio/química , Cloretos/química , Diálise , Eletroforese , Concentração de Íons de Hidrogênio , Ponto Isoelétrico , Cinética , Tamanho da Partícula , Polietilenoglicóis/química , Propriedades de Superfície
16.
Nature ; 445(7126): 402-5, 2007 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-17251973

RESUMO

Fifty years ago, Hanbury Brown and Twiss (HBT) discovered photon bunching in light emitted by a chaotic source, highlighting the importance of two-photon correlations and stimulating the development of modern quantum optics. The quantum interpretation of bunching relies on the constructive interference between amplitudes involving two indistinguishable photons, and its additive character is intimately linked to the Bose nature of photons. Advances in atom cooling and detection have led to the observation and full characterization of the atomic analogue of the HBT effect with bosonic atoms. By contrast, fermions should reveal an antibunching effect (a tendency to avoid each other). Antibunching of fermions is associated with destructive two-particle interference, and is related to the Pauli principle forbidding more than one identical fermion to occupy the same quantum state. Here we report an experimental comparison of the fermionic and bosonic HBT effects in the same apparatus, using two different isotopes of helium: (3)He (a fermion) and 4He (a boson). Ordinary attractive or repulsive interactions between atoms are negligible; therefore, the contrasting bunching and antibunching behaviour that we observe can be fully attributed to the different quantum statistics of each atomic species. Our results show how atom-atom correlation measurements can be used to reveal details in the spatial density or momentum correlations in an atomic ensemble. They also enable the direct observation of phase effects linked to the quantum statistics of a many-body system, which may facilitate the study of more exotic situations.

17.
Andrologia ; 45(1): 1-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22571172

RESUMO

Infertility is estimated to affect up to 15% of couples of reproductive age. Among the male factors, globozoospermia (also called round-headed sperm syndrome) is a rare type of teratozoospermia accounting for <0.1% of male infertility. Lack of acrosome, whose production is a postmeiotic event in spermatogenesis, and round sperm head are its main characteristics. The acrosomeless spermatozoon is unable to go through the zona pellucida and fuse with the oolemma of the oocyte, and fertilisation failures have been attributed to a deficiency in oocyte activation capacity, even when intracytoplasmic sperm injection (ICSI) is attempted. The pathogenesis of this anomaly is still unclear but genetic factors are likely to be involved. DNA fragmentation rate has been reported for 16 globozoospermic males, usually using the terminal uridine nick-end labelling (TUNEL) assay. Most of the patients had a DNA fragmentation index (DFI) higher than that in fertile men. The rate of aneuploidy for some specific chromosomes was increased in 12 among the 26 globozoospermic males reported in the literature. The same results (high DFI and aneuploidy rates) were observed in infertile males compared to fertile men, notably in those with oligoasthenozoospermia or teratozoospermia, independently of the origins. Mutations or deletions in three genes, SPATA16, PICK1 and DPY19L2, have been shown to be responsible for globozoospermia. Proteins coded by the first two genes localise to the Golgi apparatus and the proacrosomal granules that are transported in the acrosome. It is likely that other proteins involved in the acrosome formation remain to be identified.


Assuntos
Infertilidade Masculina/genética , Espermatozoides/anormalidades , Acrossomo/patologia , Acrossomo/fisiologia , Aneuploidia , Proteínas de Transporte/genética , Citogenética , Fragmentação do DNA , Proteínas de Homeodomínio/genética , Humanos , Marcação In Situ das Extremidades Cortadas , Infertilidade Masculina/patologia , Infertilidade Masculina/terapia , Masculino , Proteínas de Membrana/genética , Mutação , Proteínas Nucleares/genética , Cabeça do Espermatozoide/patologia , Injeções de Esperma Intracitoplásmicas , Interações Espermatozoide-Óvulo/genética , Interações Espermatozoide-Óvulo/fisiologia , Proteínas de Transporte Vesicular , Zona Pelúcida
18.
J Hosp Infect ; 135: 4-10, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36871872

RESUMO

BACKGROUND: Intestinal clearance of carbapenemase-producing Enterobacterales (CPE-IC) is a cornerstone to discontinue isolation precautions for CPE patients in hospitals. This study aimed to evaluate the time to spontaneous CPE-IC and identify its potential associated risk factors. METHODS: This retrospective cohort study was carried out between January 2018 and September 2020 on all patients in a 3200-bed teaching referral hospital with confirmed CPE intestinal carriage. CPE-IC was defined as at least three consecutive CPE-negative rectal swab cultures without a subsequent positive result. A survival analysis was performed to determine the median time to CPE-IC. A multivariate Cox model was implemented to explore the factors associated with CPE-IC. RESULTS: A total of 110 patients were positives for CPE, of whom 27 (24.5%) achieved CPE-IC. Median time to CPE-IC was 698 days. Univariate analysis showed that female sex (P=0.046), multiple CPE-species in index cultures (P=0.005), Escherichia coli or Klebsiella spp. (P=0.001 and P=0.028, respectively) were significantly associated with the time to CPE-IC. Multivariate analysis highlighted that identification of E. coli carbapenemase-producing or CPEs harbouring ESBL genes in index culture extended the median time to CPE-IC, respectively (adjusted hazard ratio (aHR) = 0.13 (95% confidence interval: 0.04-0.45]; P=0.001 and aHR = 0.34 (95% confidence interval: 0.12-0.90); P=0.031). CONCLUSION: Intestinal decolonization of CPE can take several months to years to occur. Carbapenemase-producing E. coli are likely to play a key role in delaying intestinal decolonization, probably through horizontal gene transfer between species. Therefore, discontinuation of isolation precautions in CPE-patients should be considered with caution.


Assuntos
Infecções por Enterobacteriaceae , Escherichia coli , Humanos , Feminino , Estudos Retrospectivos , beta-Lactamases/genética , Proteínas de Bactérias/genética , Hospitais , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/tratamento farmacológico , Antibacterianos/uso terapêutico
19.
Cytogenet Genome Res ; 133(2-4): 100-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21311180

RESUMO

Among various causes responsible for infertility, it has been admitted for a long time that male infertility can be due to impaired spermatogenesis and/or balanced structural chromosomal abnormalities. Sperm DNA fragmentation is also considered as another cause of infertility. Most of the studies on male infertility have concerned either aneuploidy in the sperm of carriers of constitutional chromosomal abnormalities or sperm DNA fragmentation. This review is aimed at analyzing these 2 parameters in the same patients. Furthermore, we present work on the study of these 2 parameters in the same gametes of 4 carriers of a balanced chromosomal abnormality. Meiotic segregation was analyzed by fluorescent in situ hybridization and DNA fragmentation was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. It was shown that aneuploidy and DNA fragmentation were increased in the sperm of carriers of a balanced chromosomal abnormality. For all 4 carriers of a balanced structural abnormality, there was a 2-5 times higher proportion of spermatozoa with unbalanced chromosomal content and fragmented DNA than among those with normal/balanced content. Moreover, we found a non-random distribution with more gametes with DNA fragmentation when these arose from a particular segregation mode. The mechanism which would tend to explain our results is abortive apoptosis. In conclusion, both meiotic segregation and DNA fragmentation studies should be integrated in the genetic exploration of male carriers of a chromosomal structural abnormality.


Assuntos
Aneuploidia , Aberrações Cromossômicas , Fragmentação do DNA , Espermatozoides , Ejaculação , Feminino , Humanos , Masculino , Interações Espermatozoide-Óvulo , Espermatozoides/metabolismo
20.
Phys Rev Lett ; 106(2): 020407, 2011 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-21405210

RESUMO

We realize a one-dimensional Josephson junction using quantum degenerate Bose gases in a tunable double well potential on an atom chip. Matter wave interferometry gives direct access to the relative phase field, which reflects the interplay of thermally driven fluctuations and phase locking due to tunneling. The thermal equilibrium state is characterized by probing the full statistical distribution function of the two-point phase correlation. Comparison to a stochastic model allows us to measure the coupling strength and temperature and hence a full characterization of the system.

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