Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
1.
Magn Reson Chem ; 58(9): 902-912, 2020 09.
Article in English | MEDLINE | ID: mdl-32526806

ABSTRACT

Cellulose-based artefacts are highly prone to degradation, especially in the presence of acidic compounds, which trigger the depolymerization of cellulose chains and lead to a loss in the original mechanical resistance of the material. Calcium hydroxide nanoparticles dispersed in organic solvent have been recently proposed for the deacidification of cellulose-based artworks. In this work, changes induced on paper by a deacidification treatment, following an acidification bath, were studied by nuclear magnetic resonance (NMR) relaxometry and by the so-called NMR diffraction of water trapped in the cellulose network. The deacidification treatment modifies intrachain and interchain bonds in hydrolyzed and degraded cellulose, leading to a buffered cellulose network configuration, which is similar to that characterizing the untreated reference sample in terms of relaxation parameters. Overall, calcium hydroxide nanoparticles are demonstrated effective in hindering the degradation of cellulose induced by acids and ageing in strong environmental conditions, even from the standpoint of cellulose network arrangement. It is worth noting, too, that the unilateral NMR device used for the relaxation measurements may represent a powerful tool for the preservation of cellulose-based artworks because it allows for the monitoring of the conservation status of cellulose in a completely non-invasive manner.

2.
J Crohns Colitis ; 13(9): 1121-1130, 2019 Sep 19.
Article in English | MEDLINE | ID: mdl-30785181

ABSTRACT

BACKGROUND: Standard high-volume polyethylene glycol [PEG] bowel preparations [PEG-4L] are recommended for patients with inflammatory bowel disease [IBD] undergoing colonoscopy. However, low-volume preparations [≤2 L of active volume] are often used in clinical practice. The aim of this study was to evaluate the efficacy, tolerability, and safety of the various bowel preparations for patients with IBD, including low-volume preparations. METHODS: We conducted a French prospective multicentre observational study over a period of 1 month. Patients aged 18-75 years with IBD with an indication of colonoscopy independent of the study were enrolled. The choice of the preparation was left to the investigators, as per their usual protocol. The patients' characteristics, disease, and colonoscopy characteristics were recorded, and they were given self-reported questionnaires. RESULTS: Twenty-five public and private hospitals enrolled 278 patients. Among them, 46 had a disease flare and 41 had bowel stenoses. Bowel preparations for colonoscopy were as follows: 42% received PEG-2L, 29% received sodium picosulfate [Pico], 15% received PEG-4L, and 14% had other preparations. The preparation did not reach the Boston's score efficacy outcome in the PEG-4L group in 51.2% of the patients [p = 0.0011]. The preparation intake was complete for 59.5% in the PEG-4L group, compared with 82.9% in the PEG-2L group and 93.8% in the Pico group [p < 0.0001]. Tolerability, as assessed by the patients' VAS, was significantly better for both Pico and PEG-2L compared with PEG-4L, and better for Pico compared with PEG-2L [p = 0.008; p = 0.0003]. In multivariate analyses, low-volume preparations were independent factors of efficacy and tolerability. Adverse events occurred in 4.3% of the patients. CONCLUSIONS: Preparations with PEG-2L and Pico were equally safe, with better efficacy and tolerability outcomes compared with PEG-4L preparations. The best efficacy/tolerance/safety profile was achieved with the Pico preparation.


Subject(s)
Cathartics , Colonoscopy/methods , Inflammatory Bowel Diseases/diagnosis , Polyethylene Glycols , Adolescent , Adult , Aged , Aged, 80 and over , Cathartics/administration & dosage , Cathartics/adverse effects , Citrates/administration & dosage , Citrates/adverse effects , Colitis, Ulcerative/diagnosis , Colonoscopy/adverse effects , Crohn Disease/diagnosis , Female , Humans , Inflammatory Bowel Diseases/pathology , Male , Middle Aged , Organometallic Compounds/administration & dosage , Organometallic Compounds/adverse effects , Picolines/administration & dosage , Picolines/adverse effects , Polyethylene Glycols/administration & dosage , Polyethylene Glycols/adverse effects , Prospective Studies , Young Adult
3.
BMC Emerg Med ; 19(1): 4, 2019 01 11.
Article in English | MEDLINE | ID: mdl-30634911

ABSTRACT

BACKGROUND: Management of spontaneous pneumothorax (SP) is still subject to debate. Although encouraging results of recent studies about outpatient management with chest drains fitted with a one-way valve, no data exist concerning application of this strategy in real life conditions. We assessed how SP are managed in Emergency departments (EDs), in particular the role of outpatient management, the types of interventions and the specialty of the physicians who perform these interventions. METHODS: From June 2009 to May 2013, all cases of spontaneous primary (PSP) and spontaneous secondary pneumothorax (SSP) from EDs of 14 hospitals in France were retrospectively included. First line treatment (observation, aspiration, thoracic drainage or surgery), type of management (admitted, discharged to home directly from the ED, outpatient management) and the specialty of the physicians were collected from the medical files of the ED. RESULTS: Among 1868 SP included, an outpatient management strategy was chosen in 179 PSP (10%) and 38 SSP (2%), mostly when no intervention was performed. Only 25 PSP (1%) were treated by aspiration and discharged to home after ED admission. Observation was the chosen strategy for 985 patients (53%). In 883 patients with an intervention (47%), it was performed by emergency physicians in 71% of cases and thoracic drainage was the most frequent choice (670 patients, 76%). CONCLUSIONS: Our study showed the low level of implementation of outpatient management for PS in France. Despite encouraging results of studies concerning outpatient management, chest tube drainage and hospitalization remain preponderant in the treatment of SP.


Subject(s)
Emergency Service, Hospital/statistics & numerical data , Pneumothorax/therapy , Adolescent , Adult , Aged , Ambulatory Care/statistics & numerical data , Emergency Medicine/statistics & numerical data , Female , France , Humans , Male , Middle Aged , Paracentesis/statistics & numerical data , Retrospective Studies , Watchful Waiting/statistics & numerical data , Young Adult
4.
Int Health ; 10(4): 237-245, 2018 07 01.
Article in English | MEDLINE | ID: mdl-29659852

ABSTRACT

Background: Primary healthcare is a key element of management of childhood illness in Africa. The objectives were to identify primary care seeking determinants among infants and young children up to 18 mo in a birth cohort from Benin. Methods: From 2007 to 2009 in Benin, a birth cohort was followed until the age of 18 mo in three health centres. Multilevel Poisson regression models were fitted to identify the factors related to the monthly number of consultations. Maternal and newborn characteristics and infant general health parameters were considered. Results: A total of 566 children were followed. On average, 0.46 consultations per month per child were recorded. The number of consultations was significantly lower after the first 6 mo of life (p<0.001). A distance >1000 m was associated with fewer consultations (p=0.01). Primiparity was significantly associated with higher care seeking (relative risk 1.17 [95% CI 1.05 to 1.30], p<0.01). No child characteristics at birth were significantly associated with the number of consultations (all p>0.16). Conclusions: Development of health structures and improvement of access remain important goals for strengthening of the primary care health system. Studying factors of care seeking behaviour, like parity, can help to identify women more prone to seek care for their child during the first year of life.


Subject(s)
Mothers/psychology , Patient Acceptance of Health Care/statistics & numerical data , Primary Health Care , Adult , Benin , Cohort Studies , Female , Humans , Infant , Infant, Newborn , Male , Mothers/statistics & numerical data , Young Adult
5.
Can Respir J ; 2017: 2729548, 2017.
Article in English | MEDLINE | ID: mdl-28465661

ABSTRACT

Introduction. Management of primary spontaneous pneumothorax (PSP) consists of immediate resolution of pleural air, or observation, and prevention of recurrence. The risk factors for recurrence remain debated. Objectives. We aimed to describe and compare the characteristics of patients presenting a first episode of PSP to those of patients presenting a recurrent PSP, in order to identify factors potentially related to recurrence. Methods. We conducted a cross-sectional study including all admissions for PSP in the EDs of fourteen French public hospitals from 2009 to 2013. PSP were classified as a first episode if the patient had no previous history of pneumothorax and as recurrence if a previous episode of spontaneous pneumothorax was documented in the patient's medical records or if a recurrence was identified during the inclusion period. To identify factors potentially associated with recurrence of PSP, multilevel logistic models were fitted. Results. During the study period, 918 (61,6%) first episodes and 573 (38,4%) episodes of recurrent PSP were identified. Clinical presentation, age, gender, smoking habits, and use of cannabis were similar in both groups. No clinical factor associated with recurrence was identified by multivariate analysis. Conclusion. In this large multicenter study, no clinical factor associated with recurrence was highlighted.


Subject(s)
Pneumothorax/epidemiology , Adult , Cross-Sectional Studies , Emergency Service, Hospital/statistics & numerical data , Female , France/epidemiology , Humans , Male , Middle Aged , Recurrence
6.
Sci Rep ; 7: 45021, 2017 03 22.
Article in English | MEDLINE | ID: mdl-28327621

ABSTRACT

The translational and orientational dynamics of water in carbon nanotubes has been studied by quasi-elastic neutron scattering from 300 down to 10 K. Results show that, reducing temperature below 200 K, part of this water behaves as a quasi-free rotor, that is, the orientational energy of such molecules becomes comparable to the rotational energy of water in the gas phase. This novel and unique dynamic behavior is related to the appearance of water molecules characterized by a coordination number of about two, which is promoted by sub-nanometer axial confinement. This peculiar molecular arrangement allows water to show an active rotational dynamics even at temperatures as low as 10 K. The translational mobility shows a behavior compatible with the rotational one.

7.
J Phys Chem Lett ; 6(11): 2038-42, 2015 Jun 04.
Article in English | MEDLINE | ID: mdl-26266499

ABSTRACT

The single-particle dynamics of hydrogen atoms in several of the amorphous ices are reported using a combination of deep inelastic neutron scattering (DINS) and inelastic neutron scattering (INS). The mean kinetic energies of the hydrogen nuclei are found to increase with increasing density, indicating the weakening of hydrogen bonds as well as a trend toward steeper and more harmonic hydrogen vibrational potential energy surfaces. DINS shows much more pronounced changes in the O-H stretching component of the mean kinetic energy going from low- to high-density amorphous ices than indicated by INS and Raman spectroscopy. This highlights the power of the DINS technique to retrieve accurate ground-state kinetic energies beyond the harmonic approximation. In a novel approach, we use information from DINS and INS to determine the anharmonicity constants of the O-H stretching modes. Furthermore, our experimental kinetic energies will serve as important benchmark values for path-integral Monte Carlo simulations.

8.
Int J Sports Med ; 36(12): 999-1007, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26252552

ABSTRACT

This study investigated changes in heart rate variability (HRV) in elite Nordic-skiers to characterize different types of "fatigue" in 27 men and 30 women surveyed from 2004 to 2008. R-R intervals were recorded at rest during 8 min supine (SU) followed by 7 min standing (ST). HRV parameters analysed were powers of low (LF), high (HF) frequencies, (LF+HF) (ms(2)) and heart rate (HR, bpm). In the 1 063 HRV tests performed, 172 corresponded to a "fatigue" state and the first were considered for analysis. 4 types of "fatigue" (F) were identified: 1. F(HF(-)LF(-))SU_ST for 42 tests: decrease in LFSU (- 46%), HFSU (- 70%), LFST (- 43%), HFST (- 53%) and increase in HRSU (+ 15%), HRST (+ 14%). 2. F(LF(+) SULF(-) ST) for 8 tests: increase in LFSU (+ 190%) decrease in LFST (- 84%) and increase in HRST (+ 21%). 3. F(HF(-) SUHF(+) ST) for 6 tests: decrease in HFSU (- 72%) and increase in HFST (+ 501%). 4. F(HF(+) SU) for only 1 test with an increase in HFSU (+ 2161%) and decrease in HRSU (- 15%). Supine and standing HRV patterns were independently modified by "fatigue". 4 "fatigue"-shifted HRV patterns were statistically sorted according to differently paired changes in the 2 postures. This characterization might be useful for further understanding autonomic rearrangements in different "fatigue" conditions.


Subject(s)
Autonomic Nervous System/physiology , Fatigue/physiopathology , Heart Rate/physiology , Skiing/physiology , Female , Humans , Male , Posture/physiology , Principal Component Analysis
9.
J Chem Phys ; 137(9): 094908, 2012 Sep 07.
Article in English | MEDLINE | ID: mdl-22957595

ABSTRACT

Structure and dynamics of water confined in channels of diameter of few nanometer in size strongly differ from the ones of water in the bulk phase. Here, we present radiowave dielectric relaxation measurements on water-filled single-walled carbon nanotubes, with the aim of highlighting some aspects on the molecular electric dipole organization of water responding to high spatial confinement in a hydrophobic environment. The observed dielectric spectra, resulting into two contiguous relaxation processes, allow us to separate the confined water in the interior of the nanotubes from external water, providing support for the existence in the confinement region of water domains held together by hydrogen bonds. Our results, based on the deconvolution of the dielectric spectra due to the presence of a bulk and a confined water phase, furnish a significantly higher Kirkwood correlation factor, larger than the one of water in bulk phase, indicating a strong correlation between water molecules inside nanotubes, not seen in bulk water.

11.
J Clin Psychol ; 55(1): 79-86, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10100834

ABSTRACT

The Profile of Mood States (POMS; McNair, Lorr, & Droppleman) is widely used to assess mood states. However, the utility of the POMS has been restricted by the lack of normative data from the general population. We report on our adult (N = 400) and geriatric (N = 170) POMS standardization samples. Both groups were age-, gender-, and race-stratified according to 1990 census data. We also report on convergent and discriminant validity of POMS scales, using a multitrait, multimethod paradigm.


Subject(s)
Affect/classification , Geriatric Psychiatry , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Psychiatric Status Rating Scales/standards , Psychiatric Status Rating Scales/statistics & numerical data , Reference Values , Sensitivity and Specificity
SELECTION OF CITATIONS
SEARCH DETAIL