Performance characteristics of a new structured packing

A new structured packing using carbon fibres, called Sepcarb® 4D, is presented. This packing has several attractive properties, such as high voidage (ε=94%) and high effective area (a=420 m2 m−3). These properties are advantageous for packing used as a gas–liquid contactor for separation units. To determine the internal characteristics of this packing, we performed several experiments using a 150-mm-internal-diameter column. Firstly, hydrodynamics experiments were conducted using an air–water counter current flow to determine the pressure drop (for both dry and wet packing) and flooding point. Secondly, the mass transfer efficiency was determined in terms of HETP (height equivalent to theoretical plate) by total reflux experiments with an n-heptane/cyclohexane mixture at atmospheric pressure. Hydrodynamic performance and mass transfer efficiency were compared with those of packings generally used in distillation and absorption

Image restoration using sparse approximations of spatially varying blur operators in the wavelet domain

6 pagesInternational audienceRestoration of images degraded by spatially varying blurs is an issue of increasing importance in the context of photography, satellite or microscopy imaging. One of the main difficulty to solve this problem comes from the huge dimensions of the blur matrix. It prevents the use of naive approaches for performing matrix-vector multiplications. In this paper, we propose to approximate the blur operator by a matrix sparse in the wavelet domain. We justify this approach from a mathematical point of view and investigate the approximation quality numerically. We finish by showing that the sparsity pattern of the matrix can be pre-defined, which is central in tasks such as blind deconvolution

Azithromycin fails to reduce increased expression of neutrophil-related cytokines in primary-cultured epithelial cells from cystic fibrosis mice

AbstractBackgroundBeneficial effects of azithromycin in cystic fibrosis (CF) have been reported, however, its mechanism of action remains unclear. The present study aimed at investigating the effect of azithromycin on CF airway epithelial cells.MethodsPrimary cultures of purified tracheal epithelial cells from F508del and normal homozygous mice were established. Responses to lipopolysaccharide from Pseudomonas aeruginosa (LPS, 0.1 µg/ml) on mRNA expression of neutrophil-related chemokines, pro- and anti-inflammatory cytokines were investigated in the presence or the absence of azithromycin (1 µg/ml).ResultsCF airway epithelial cells showed upregulation of MIP-2 and KC responses to LPS, and azithromycin failed to downregulate these responses. In contrast, in CF cells, azithromycin increased KC and TNF-α expression under non-stimulated and LPS-stimulated conditions, respectively. In non-CF cells, the macrolide potentiated the LPS response on MIP-2 and on IL-10.ConclusionsAirway epithelial cells contribute to the dysregulated immune processes in CF. Azithromycin rather stimulates cytokine expression in CF airway epithelial cells

Врожденные мышечные дистрофии: классификация и диагностика

Congenital muscular dystrophies (CMD) are a large group of genetically determined muscular diseases, initially defined by an early onset before the age of walking and dystrophic changes on myopathologic analyses. Currently, their definition is less restrictive with, a clinical continuum with limb-girdle muscular dystrophies, and closer histomorphological aspects with congenital myopathies. We distinguish 9 different forms of DMC, classified in 6 different groups depending on the location and/or function of the protein involved, on the control of 26 different genes. Ullrich's disease, UCMD (collagenopathy involving three different genes: COL6A1, COL6A2, COL6A3); secondary dystroglycanopathies (by abnormal glycosylation of alpha-dystroglycan involving 16 different genes); and DMC merosin negative, MDC1A, (merosinopathy secondary to mutations in a unique gene, LAMA2); represent the three most common forms. Rigid spine syndrome type 1, RSMD1 (selenopathy secondary to SEPN1 gene mutation) and L-CMD (laminopathy involving LMNA gene) are also part of the most current forms. Clinical features, plasmatic creatine kinase elevation or not, the presence or absence of clinical signs of central nervous system involvement, allow a first level of diagnostic pathway. According to these elements, muscle and/or cerebral MRI, muscle and/or skin biopsy will be discussed to guide the molecular investigations that will allow accurate diagnosis.Врожденные мышечные дистрофии (ВМД) составляют клинически и генетически чрезвычайно гетерогенную группу мышечных заболеваний. Изначально ВМД рассматривались как группа болезней с дебютом в раннем детском возрасте, до начала самостоятельной ходьбы, и наличием признаков дистрофии при патогистологическом исследовании. Сегодня ВМД подразделяют не столь строго. Так, имеется целый спектр клинических форм, включающий дистрофии поясов с более поздним дебютом игистологической картиной, сближающей их с врожденными миопатиями. Различают 9 форм ВМД, распределенных на 6 групп согласно локализации и/или функции нарушенного белка и соответствующего одному из 26 генов. Чаще всего встречаются следующие формы ВМД: болезнь Ульриха (коллагенопатия, связанная с патологией 3 генов: COL6A1, COL6A2, COL6A3); вторичные дистрогликанопатии (нарушение гликозилирования α-дистрогликана с вовлечением 16 генов) и мерозин-дефицитная ВМД (мерозинопатия, обусловленная мутацией одного гена LAMA2). К классическим формам ВМД также относятся синдром ригидного позвоночника 1-го типа (селенопатия вследствие мутации гена SEPN) и L-ВМД (ламинопатия, вовлекающая ген LMNA). Диагностический поиск определяется выявлением характерной клинической картины, наличием или отсутствием признаков поражения центральной нервной системы, нормальным или умеренно повышенным уровнем креатинфосфокиназы. Выбор молекулярного исследования для уточнения диагноза определяется результатами предварительного лабораторно-инструментального обследования, включающего магнитно-резонансную томографию мышц и/или головного мозга, биопсии мышцы и/или кожи

The Logarithmic Sobolev Constant of The Lamplighter

We give estimates on the logarithmic Sobolev constant of some finite lamplighter graphs in terms of the spectral gap of the underlying base. Also, we give examples of application

Variety of stylolites morphologies and statistical characterization of the amount of heterogeneities in the rock

The surface roughness of several stylolites in limestones was measured using high resolution laser profilometry. The 1D signals obtained were statistically analyzed to determine the scaling behavior and calculate a roughness exponent, also called Hurst exponent. Statistical methods based on the characterization of a single Hurst exponent imply strong assumptions on the mathematical characteristics of the signal: the derivative of the signal (or local increments) should be stationary and have finite variance. The analysis of the measured stylolites show that these properties are not always verified simultaneously. The stylolite profiles show persistence and jumps and several stylolites are not regular, with alternating regular and irregular portions. A new statistical method is proposed here, based on a non-stationary but Gaussian model, to estimate the roughness of the profiles and quantify the heterogeneity of stylolites. This statistical method is based on two parameters: the local roughness (H) which describes the local amplitude of the stylolite, and the amount of irregularities on the signal (\mu), which can be linked to the heterogeneities initially present in the rock before the stylolite formed. Using this technique, a classification of the stylolites in two families is proposed: those for which the morphology is homogeneous everywhere and those with alternating regular and irregular portions

Loss of independence in Katz's ADL ability in connection with an acute hospitalization: early clinical markers in French older people

Background: The preservation of autonomy and the ability of elderly to carry out the basic activities of daily living, beyond the therapeutic care of any pathologies, appears as one of the main objectives of care during hospitalization. Objectives: To identify early clinical markers associated with the loss of independence in elderly people in short stay hospitals. Methods: Among the 1,306 subjects making up the prospective and multicenter SAFEs cohort study (Sujet Agé Fragile: Évolution et suivi—Frail elderly subjects, evaluation and follow-up), 619 medical inpatients, not disabled at baseline and hospitalized through an emergency department were considered. Data used in a multinomial logistic regression were obtained through a comprehensive geriatric assessment (CGA) conducted in the first week of hospitalization. Dependency levels were assessed at baseline, at inclusion and at 30days using Katz's ADL index. Baseline was defined as the dependence level before occurrence of the event motivating hospitalization. To limit the influence of rehabilitation on the level of dependence, only stays shorter than 30days were considered. Results: About 514 patients were eligible, 15 died and 90 were still hospitalized at end point (n=619). Two-thirds of subjects were women, with a mean age of 83. At day 30 162 patients (31%) were not disabled; 61 (12%) were moderately disabled and 291 severely disabled (57%). No socio-demographic variables seemed to influence the day 30 dependence level. Lack of autonomy (odds ratio (OR)=1.9, 95% confidence interval (CI)=1.2-3.6), walking difficulties (OR=2.7, 95% CI=1.3-5.6), fall risk (OR=2.1, 95% CI=1.3-6.8) and malnutrition risk (OR=2.2, 95% CI=1.5-7.6) were found in multifactorial analysis to be clinical markers for loss of independence. Conclusions: Beyond considerations on the designing of preventive policies targeting the populations at risk that have been identified here, the identification of functional factors (lack of autonomy, walking difficulties, risk of falling) suggests above all that consideration needs to be given to the organization per se of the French geriatric hospital care system, and in particular to the relevance of maintaining sector-type segregation between wards for care of acute care and those involved in rehabilitatio

Longitudinal blood biomarker trajectories in preclinical Alzheimer's disease

INTRODUCTION: Plasma biomarkers are altered years prior to Alzheimer's disease (AD) clinical onset. METHODS: We measured longitudinal changes in plasma amyloid-beta (Aβ)42/40 ratio, pTau181, pTau231, neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) in a cohort of older adults at risk of AD (n = 373 total, n = 229 with Aβ and tau positron emission tomography [PET] scans) considering genetic and demographic factors as possible modifiers of these markers' progression. RESULTS: Aβ42/40 ratio concentrations decreased, while NfL and GFAP values increased over the 4-year follow-up. Apolipoprotein E (APOE) ε4 carriers showed faster increase in plasma pTau181 than non-carriers. Older individuals showed a faster increase in plasma NfL, and females showed a faster increase in plasma GFAP values. In the PET subsample, individuals both Aβ-PET and tau-PET positive showed faster plasma pTau181 and GFAP increase compared to PET-negative individuals. DISCUSSION: Plasma markers can track biological change over time, with plasma pTau181 and GFAP markers showing longitudinal change in individuals with preclinical AD. HIGHLIGHTS: Longitudinal increase of plasma pTau181 and glial fibrillary acidic protein (GFAP) can be measured in the preclinical phase of AD. Apolipoprotein E ε4 carriers experience faster increase in plasma pTau181 over time than non-carriers. Female sex showed accelerated increase in plasma GFAP over time compared to males. Aβ42/40 and pTau231 values are already abnormal at baseline in individuals with both amyloid and tau PET burden

AP4 deficiency: A novel form of neurodegeneration with brain iron accumulation?

OBJECTIVE: To describe the clinico-radiological phenotype of 3 patients harboring a homozygous novel AP4M1 pathogenic mutation. METHODS: The 3 patients from an inbred family who exhibited early-onset developmental delay, tetraparesis, juvenile motor function deterioration, and intellectual deficiency were investigated by magnetic brain imaging using T1-weighted, T2-weighted, T2*-weighted, fluid-attenuated inversion recovery, susceptibility weighted imaging (SWI) sequences. Whole-exome sequencing was performed on the 3 patients. RESULTS: In the 3 patients, brain imaging identified the same pattern of bilateral SWI hyposignal of the globus pallidus, concordant with iron accumulation. A novel homozygous nonsense mutation was identified in AP4M1, segregating with the disease and leading to truncation of half of the adap domain of the protein. CONCLUSIONS: Our results suggest that AP4M1 represents a new candidate gene that should be considered in the neurodegeneration with brain iron accumulation (NBIA) spectrum of disorders and highlight the intersections between hereditary spastic paraplegia and NBIA clinical presentations