598 research outputs found
Electromagnetic response of LaO_0.94F_0.06FeAs: AC susceptibility and microwave surface resistance
We discuss on the electromagnetic response of a polycrystalline sample of
LaO_0.94F_0.06FeAs exposed to DC magnetic fields up to 10 kOe. The low- and
high-frequency responses have been investigated by measuring the AC
susceptibility at 100 kHz and the microwave surface resistance at 9.6 GHz. At
low as well as high DC magnetic fields, the susceptibility strongly depends on
the amplitude of the AC driving field, highlighting enhanced nonlinear effects.
The field dependence of the AC susceptibility exhibits a magnetic hysteresis
that can be justified considering the intragrain-field-penetration effects on
the intergrain critical current density. The microwave surface resistance
exhibits a clockwise magnetic hysteresis, which cannot be justified in the
framework of the critical-state models of the Abrikosov-fluxon lattice; it may
have the same origin as that detected in the susceptibility.Comment: 8 pages, 4 embedded eps figures; Proceedings of the 9th EUCAS
Conference (Dresden, Germany, September 13-17, 2009
Fatal intrahepatic hemorrhage after nadroparin use for total hip arthroplasty.
Low-molecular-weight heparins have become the predominant choice for deep venous thrombosis prophylaxis and treatment. However, their use may cause bleeding complications. Intrahepatic bleeding is exceptional and only very few cases have been described. The authors present a unique case of fatal intrahepatic hematoma complicating nadroparin use in a 65-year-old woman with a hepatic cyst who was admitted to hospital for unilateral total hip arthroplasty. At autopsy, hemoperitoneum (2,000 ml of blood and clots) was evident. A ruptured sub-capsular hematoma involving the right lobe of the liver was observed. The hemorrhage within the cyst induced by the nadroparin use was likely responsible for the subsequent hepatic hematoma, liver rupture, and death. This case highlights the need for pathologists and surgeons to be aware of the possibility of intrahepatic hematoma in patients who have received low-molecular-weight heparins, undergone major surgery and present postoperative hemodynamic instability, especially in those with preoperative diagnosis of hepatic cyst
Endurance training damages small airway epithelium in mice.
RATIONALE: In athletes, airway inflammatory cells were found to be increased in
induced sputum or bronchial biopsies. Most data were obtained after exposure to
cold and dry air at rest or during exercise. Whether training affects epithelial
and inflammatory cells in small airways is unknown.
OBJECTIVES: To test whether endurance training under standard environmental
conditions causes epithelial damage and inflammation in the small airways of
mice.
METHODS AND MEASUREMENTS: Formalin-fixed, paraffin-embedded lung sections were
obtained in sedentary (n = 14) and endurance-trained (n = 16) Swiss mice at
baseline and after 15, 30, and 45 days of training. The following variables were
assessed (morphometry and immunohistochemistry) in small airways (basement
membrane length < 1 mm): (1) integrity, proliferation, and apoptosis of
bronchiolar epithelium; and (2) infiltration, activation, and apoptosis of
inflammatory cells.
MAIN RESULTS: Compared with sedentary mice, bronchiolar epithelium of trained
mice showed progressive loss of ciliated cells, slightly increased thickness,
unchanged goblet cell number and appearance, and increased apoptosis and
proliferation (proliferating cell nuclear antigen) (p < 0.001 for all variables).
Leukocytes (CD45(+) cells) infiltrated airway walls (p < 0.0001) and accumulated
within the lumen (p < 0.001); however, apoptosis of CD45(+) cells did not differ
between trained and sedentary mice. Nuclear factor-kappaB translocation and
inhibitor-alpha of NF-kappaB (IkappaBalpha) phosphorylation were not increased in
trained compared with sedentary mice.
CONCLUSIONS: Bronchiolar epithelium showed damage and repair associated with
endurance training. Training increased inflammatory cells in small airways, but
inflammatory activation was not increased. These changes may represent an
adaptive response to increased ventilation during exercise
Respiratory Effects of Exposure to Traffic-Related Air Pollutants During Exercise
Traffic-related air pollution (TRAP) is increasing worldwide. Habitual physical activity is known to prevent cardiorespiratory diseases and mortality, but whether exposure to TRAP during exercise affects respiratory health is still uncertain. Exercise causes inflammatory changes in the airways, and its interaction with the effects of TRAP or ozone might be detrimental, for both athletes exercising outdoor and urban active commuters. In this Mini-Review, we summarize the literature on the effects of exposure to TRAP and/or ozone during exercise on lung function, respiratory symptoms, performance, and biomarkers. Ozone negatively affected pulmonary function after exercise, especially after combined exposure to ozone and diesel exhaust (DE). Spirometric changes after exercise during exposure to particulate matter and ultrafine particles suggest a decrease in lung function, especially in patients with chronic obstructive pulmonary disease. Ozone frequently caused respiratory symptoms during exercise. Women showed decreased exercise performance and higher symptom prevalence than men during TRAP exposure. However, performance was analyzed in few studies. To date, research has not identified reliable biomarkers of TRAP-related lung damage useful for monitoring athletes' health, except in scarce studies on airway cells obtained by induced sputum or bronchoalveolar lavage. In conclusion, despite partly counteracted by the positive effects of habitual exercise, the negative effects of TRAP exposure to pollutants during exercise are hard to assess: outdoor exercise is a complex model, for multiple and variable exposures to air pollutants and pollutant concentrations. Further studies are needed to identify pollutant and/or time thresholds for performing safe outdoor exercise in cities
Bronchial hyperresponsiveness in children with atopic rhinitis: a 7-year follow-up
A high prevalence of bronchial hyperresponsiveness (BHR) was found in atopic subjects with rhinitis. Those subjects may be at higher risk for developing bronchial asthma. We evaluated, in a 7-year follow-up, BHR and atopy in a homogeneous population of nonasthmatic children with allergic rhinitis (AR), and their role in asthma development
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Technology and future prospects for lightweight plastic vehicle structures
The state of the technology and the materials and processing issues of using plastics in vehicle body applications (structural and semistructural) were assessed. Plastics are significantly lighter in weight, more easily fabricated into complex shapes, and more corrosion resistance than sheet steel, high-strength steel, or aluminum. However, at their current stage of development, plastics are deficient in one or more necessary properties: heat resistance and dimensional stability, stiffness and tensile strength, toughness, and impact resistance. To upgrade their physical properties for automotive chassis/body applications, plastics need to be compounds with suitable reinforcing fibers. As a short-term approach, the material of choice is a composite structure made with low-cost glass-fiber reinforcement, such as that made in the resin-transfer-molding (RTM) process and used in the body of the Dodge Viper. However, RTM technology based on thermosets requires a processing cycle time that is too long for large production runs. Adaptation of RTM to the formation of thermoplastic composite bodies could have a significant advantage over thermoset technology. Cyclic oligomers, which are precursors to thermoplastic matrix polymers, show promise for this application. Farther on the horizon are advanced composites compounds with the much more expensive (but stronger and stiffer) carbon-fiber reinforcement. However, significant price reductions of precursor materials and advances in processing and fabrication would be needed. Other materials holding promise are liquid crystal polymers (LCP) and LCP blends with other polymers (molecular composites). However, the cost of monomers and the subsequent polymerization technology also remains a considerable drawback to the widespread and increasing acceptance of LCPs
La produzione di ceramica da mensa a Solunto: un esempio di continuit\ue0 tecnologica dall\u2bcet\ue0 arcaica a quella ellenistico-romana.
Solunto is one of the most important Phoenician-Punic colonies of north-western Sicily. Archaeometric researches carried
out in the last years ascertained a local production of transport amphorae during Archaic and Classic age (7th-5th century
B.C.) through mineralogical, petrographical and chemical analysis of ceramic samples, kiln refuses and local raw materials
(clays and alluvial sands). In connection with these earliest works, the present paper was focused on some specific forms
of fine-tempered table ware of Archaic age and/or Classic-Hellenistic age. This pottery has been recurrently brought to light
in Solunto and it is furthermore suspected to be, at least to some extent, a local reproduction. Thus a representative number
of samples corresponding in style and morphology to Greek-colonial productions were subjected to thin-section and chemical
analysis. Simultaneously, the same analytical routine was applied to an Hellenistic black-gloss ware form (Campana A), the
plate classified as Lamboglia 36, considering a number of samples coming from Solunto as well as from others close centers.
In both the cases the comparative elaboration of petrographic and chemical data concerning the ceramic samples and local
raw clays let us to distinguish between the products made in the Solunto\u2bcs kilns and the imports from Greece or the Greek
colony of Himera or from the Gulf of Naples area (for the black-gloss ware samples). Therefore, a durability of the
manufacture crosswise more than four centuries was demonstrated for the ceramic kilns which were working at Solunto,
which were able to reproduce several fine ware forms testifying an high technological level
Associations of dry skin, skin care habits, well‐being, sleep quality and itch in nursing home residents : results of a multicentre, observational, cross‐sectional study
Aim: Dry skin is one of the most frequent cutaneous problems in aged long-term care residents. Although it is clinically relevant, the impact on quality of life is unclear. The objective was to measure well-being, sleep quality and itch in nursing home residents being 65 years and older and to explore possible associations with demographics, dry skin and skincare habits.
Design: Multicentre, observational, cross-sectional.
Methods: Sleep quality was assessed with the Richards-Campbell Sleep Quality Questionnaire, well-being with the WHO-Five Well-being Index and itch with the 5-D Itch scale. Skin dryness was measured using the Overall Dry Skin score.
Results: A total of 51 residents were included. The item scores of the sleep quality and itch questionnaires were strongly associated with each other. Demographics, dry skin and skincare habits were not associated with the questionnaires. It is unclear whether basic skincare activities can improve the quality of life in this population
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