Since the late 1990s, Stenotrophomonas maltophilia (S. maltophilia) has become one of the most common nonfermenting Gram-negative bacilli that cause opportunistic infection. Patients with hematologic diseases are the most risky candidate for S. maltophilia pneumonia or sepsis because of chemotherapy-induced neutropenia or immunodeficiency. Frequent exposure to broad-spectrum antibiotics and prolonged insertion of central venous catheter further enhance the risk of S. maltophilia infection. One of the most severe S. maltophilia infections is hemorrhagic pneumonia. This type of infection is mostly fatal because of pulmonary alveolar hemorrhage that leads to acute respiratory failure. Furthermore, S. maltophilia exhibits a high-level intrinsic resistance to conventional antibiotics such as β-lactams and aminoglycosides and, more recently, the increasing acquired resistance to co-trimoxazole and quinolones. According to our experienced and previously reported cases, all of the patients with hemorrhagic pneumonia caused by S. maltophilia had a fatal course within a few days after the onset of the pneumonia. In this article, we perform a systematic review on a total 30 cases of hemorrhagic pneumonia induced by S. maltophilia from our institutions and the literature, and we describe its early diagnosis, prophylaxis, and recommended therapeutic strategy for the infection in the treatment of hematologic disease.
SUMMARYIt is well known that highly porous rocks under relatively high confining pressure succumb to volumetric compression with the emergence of the so-called compaction bands. These normally occur as perpendicular or very slightly inclined deformation bands with respect to the direction of the most compressive principal stress. An experimental study of diatomaceous mudstone, a highly structured and porous soft rock, was conducted to demonstrate the existence of compaction bands in laboratory tests. In these tests, the local strain field on the specimen's face is determined by means of image analysis. The main objective of this paper is the numerical simulation of compaction bands in diatomaceous mudstone. First, an elastoviscoplastic model considering microstructural degradation is used to simulate the behavior of diatomaceous mudstone at the element test level. It has been found that such a model can accurately reproduce the stress-strain and dilatancy responses of diatomaceous mudstone. Then, a numerical analysis of a series of triaxial compression tests under drained conditions was carried out using the elasto-viscoplastic model within the framework of Biot's theory for a two-phase mixture. As a boundary problem, the triaxial tests were analyzed via finite elements with an updated Lagrangian formulation to simulate strain localization behavior under large deformations. The present study demonstrates that it is indeed possible to successfully simulate the experimentally observed compaction bands in diatomaceous mudstone.
Objective While unexplained liver dysfunction is common, it is sometimes difficult to identify its exact cause. One cause is viral infections. The identification of viruses other than hepatitis B and C that cause liver dysfunction is difficult because no methods to simultaneously identify these viruses have been established. The aim of this study was to quickly and simultaneously identify multiple virus species. Methods A total of 49 patients with unexplained liver dysfunction and undetermined inflammation were examined. The majority of patients had hematologic malignancies, and some had undergone bone marrow transplantation. Qualitative polymerase chain reactions (PCR) were performed to detect 12 species of DNA virus in whole blood. Quantitative real-time PCR was performed when a specific virus was amplified. In addition, 6 RNA hepatitis viruses were directly assayed by real-time PCR. These 2 PCR steps were completed within 1 hour. Results The most frequently detected virus in 37 patients with liver dysfunction, was transfusion transmitted virus (38%), which was followed by human herpes virus (HHV) type 6 (35%), Epstein-Barr virus (14%), cytomegalovirus (8%), and rarely hepatitis G virus and HHV-7 (3%). Similar viremia was observed in 12 patients with mild liver dysfunction. The results of the PCR assay were mostly consistent with those of routine virus serological tests. Conclusion A multiplex viral PCR assay was a useful tool for quickly identifying viruses that possibly cause liver dysfunction. It was also important that liver dysfunction acted as a proband that led to the discovery of serious viremia.
The modelling of non-linear stifaffess, based on elastic characteristic moduli for stiff geomaterials, is proposed, on the basis of the results of a large number of triaxial compression tests on sedimentary soft rocks, tuff, weathered granite, cement-treated soils, densely compacted gravels and sands. Axial strains from less than 0·001% to about 1% were measured by using a local gauge, while elastic Young's moduli E sbp e were obtained by applying a series of small unload/reload cycles of axial stress during each monotonic loading test. Strain increments less than about 0·001% were nearly recoverable and strain-rate-independent. For sedimentary soft rocks and cement-treated soils, the elastic Young's moduli E e from laboratory tests using high-quality undisturbed samples were very similar to the equivalent values obtained from field seismic surveys. The dependence of E e on stress state is summarized, and the effects of geomaterial type are analysed. The non-linearity during shear deformation is regarded as being caused by damage to the elastic deformation properties and the occurrence of plastic strains. The effects of cementation and structuration on elastic deformation properties are discussed. A method to estimate the tangent Young's modulus E sub tan /sub of a given geomaterial at a given stress state from the E e value evaluated by field seismic surveys and the non-linear tangent stifaffess model is proposed. L'article prisente une mod6lisation de la rigidité non linéaire basée sur les modules d'élasticité de matériaux rigides, qui repose sur les résultats d'un grand nombre d'essais de compression triaxiale sur des ruches tendres sédimentaires, du tuf, du granit désagrégé, des sols traités au ciment, des graviers fortement tassés et des sables. Un extensomètre local a permis de me-surer des contraintes axiales allant de moins de 0,001% a 1% environ, tandis qu'une série de cycles de décharge/recharge de contraintes axiales pendant chaque essai de charge monotone a permis d'obtenir des modules d'élasticité E e de Young. Les écarts de contrainte de moins de 0,001% étaient presque récupérables et ne dé- pendaient pas du taux de contrainte. Dans le cas des ruches tendres sédimentaires et des sols traités au ciment, les essais de laboratoire sur des échantillons non perturbés de grande qualité ont produit des modules d'élasticité E sub e /sub trés semblables aux valeurs correspondantes fournies par les relevés sismiques sur le terrain. Ľarticle résume la façon dont ľélasticité E e dépend de ľétat de contrainte et analyse les effets du type de matériau. La modélisation suppose que la nonlinéarité du cisaillement est causée par la détérioration de ľéasticité et ľapparition de déformations plastiques. Ľarticle examine les effets de la cimentation et de la structuration sur les propriétés des matériaux. Enfin, il propose une méthode qui permet d'estimer le module tangent de Young E sub tan /sub d'un matériau donné à un état de contrainte donné, à partir de la valeur E e évaluée à ľaide des levés sismiques sur le terrain et du module de rigidité tangentielle non linéaire.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.