Conventional contact sensors used for Lamb wave-based ultrasonic inspection, such as piezo-electric transducers, measure omnidirectional strain and do not allow distinguishing between fundamental symmetric and anti-symmetric modes. In this paper, we show that the use of a single fibre Bragg grating created in a dedicated microstructured optical fibre allows one to directly make the distinction between these fundamental Lamb wave modes. This feature stems from the different sensitivities of the microstructured fibre to axial and transverse strain.
View Article and Find Full Text PDFExcessive fuel assembly vibrations in nuclear reactor cores should be avoided in order not to compromise the lifetime of the assembly and in order to prevent the occurrence of safety hazards. This issue is particularly relevant to new reactor designs that use liquid metal coolants, such as, for example, a molten lead-bismuth eutectic. The flow of molten heavy metal around and through the fuel assembly may cause the latter to vibrate and hence suffer degradation as a result of, for example, fretting wear or mechanical fatigue.
View Article and Find Full Text PDFThe working principle of fiber Bragg grating (FBG) sensors is mostly based on the tracking of the Bragg wavelength shift. To accomplish this task, different algorithms have been proposed, from conventional maximum and centroid detection algorithms to more recently-developed correlation-based techniques. Several studies regarding the performance of these algorithms have been conducted, but they did not take into account spectral distortions, which appear in many practical applications.
View Article and Find Full Text PDFYeasts and moulds now rank amongst the 10 most frequently isolated pathogens in febrile patients with an impaired immune system. Fungi are mainly opportunistic pathogens that only invade the body if a severely weakened natural defense permits them to do so. Most factors facilitating an invasive fungal infection are unavoidable because they are directly connected to the underlying diseases as well as to their treatment.
View Article and Find Full Text PDFJ Antimicrob Chemother
January 2011
The management of invasive fungal disease in the immunocompromised host is complex and requires the specialized knowledge of physicians whose primary interest is actually the underlying disease rather than infectious complications. This Supplement aims to provide these physicians with some tools that may help to guide them through the maze of suspicion that an invasive fungal disease is present by offering an integrated care pathway of rational patient management. Such pathways will inevitably vary in detail in different centres and depend for their success on the presence of multidisciplinary teams and an explicit agreement on at least the minimum requirements for effective management.
View Article and Find Full Text PDFBackground: Persistently febrile neutropenic children at risk for invasive fungal infections receive empiric antifungal therapy as a standard of care. However, little is known about the role of echinocandins and liposomal amphotericin B (L-AmB) for empiric antifungal therapy in pediatric patients.
Methods: Patients between the ages of 2 to 17 years with persistent fever and neutropenia were randomly assigned to receive caspofungin (70 mg/m loading dose on day 1, then 50 mg/m daily [maximum 70 mg/d]) or L-AmB (3 mg/kg daily) in a 2:1 ratio.
Int J Antimicrob Agents
November 2008
Recent advances have made it possible to treat successfully conditions that for many years were considered incurable. In many cases, aggressive therapeutic or diagnostic techniques have been used. One resulting adverse event is a severely diminished immune response that, given the patient's situation, demands accurate and rapid treatment.
View Article and Find Full Text PDFInvasive fungal diseases (IFDs) have become major causes of morbidity and mortality among highly immunocompromised patients. Authoritative consensus criteria to diagnose IFD have been useful in establishing eligibility criteria for antifungal trials. There is an important need for generation of consensus definitions of outcomes of IFD that will form a standard for evaluating treatment success and failure in clinical trials.
View Article and Find Full Text PDFBackground: Invasive fungal diseases are important causes of morbidity and mortality. Clarity and uniformity in defining these infections are important factors in improving the quality of clinical studies. A standard set of definitions strengthens the consistency and reproducibility of such studies.
View Article and Find Full Text PDFPrevious studies demonstrated that 20% of haemoglobin is lost from circulating erythrocytes during their total lifespan by vesiculation. To study whether removal molecules other than membrane-bound haemoglobin were present in erythrocyte-derived vesicles, flow cytometry and immunoblot analysis were employed to examine the presence of phosphatidylserine (PS) and IgG, and senescent cell antigens respectively. It was demonstrated that 67% of glycophorin A-positive vesicles exposed PS, and that half of these vesicles also contained IgG.
View Article and Find Full Text PDFTranspl Infect Dis
September 2007
Unlabelled: The coagulation-fibrinolytic profile during cardiopulmonary bypass (CPB) has been widely documented. However, less information is available on the possible persistence of these alterations when autotransfusion is used in management of perioperative blood loss. This study was designed to explore the influence of autotransfusion management on intravascular fibrin degradation and postoperative transfusions.
View Article and Find Full Text PDFTwo highly discriminatory fingerprinting assays, short tandem repeat typing and amplified fragment length polymorphism (AFLP), were compared to determine the genetic relatedness between 55 isolates of Aspergillus fumigatus obtained from 15 different patients suffering from proven invasive aspergillosis. Both techniques showed that interpatient isolates belonged to different genotypes and that intrapatient isolates from deep sites were all of the same genotype. By contrast, multiple genotypes were found among isolates originating from respiratory samples.
View Article and Find Full Text PDFBackground: Computed tomography (CT) of the chest may be used to identify the halo sign, a macronodule surrounded by a perimeter of ground-glass opacity, which is an early sign of invasive pulmonary aspergillosis (IPA). This study analyzed chest CT findings at presentation from a large series of patients with IPA, to assess the prevalence of these imaging findings and to evaluate the clinical utility of the halo sign for early identification of this potentially life-threatening infection.
Methods: Baseline chest CT imaging findings from 235 patients with IPA who participated in a previously published study were systematically analyzed.
Invasive mold infection is a major cause of morbidity and mortality among severely immunocompromised individuals. We discuss the challenges involved in the design and interpretation of salvage antifungal trials, focusing on mold infection. We suggest that patients with refractory fungal infection be analyzed separately from those with intolerance to standard regimens because of the poorer prognosis of the former group.
View Article and Find Full Text PDFBackground: Yeasts and molds now rank among the most common pathogens in intensive care units. Whereas the incidence of Candida infections peaked in the late 1970s, aspergillosis is still increasing.
Method: Review of the pertinent English-language literature.
Rev Clin Exp Hematol
December 2005
Opportunistic infections have always been pitfalls on the road of progress in the treatment of diseases that are accompanied by compromised host defences. Because of the severe morbidity and mortality associated with these infections, they have become substantial challenges for the clinicians who offer such patients care. With medical progress, the number of immunocompromised patients is still steadily climbing and it has become evident that deficiencies in host defences mechanisms are multiple as well as changing in harmony with alterations in treatment modalities for underlying diseases.
View Article and Find Full Text PDFBackground: In a previous randomized trial of voriconazole versus amphotericin B deoxycholate for primary therapy of invasive aspergillosis, voriconazole demonstrated superior efficacy and better survival. In that trial, treatment with voriconazole or amphotericin B deoxycholate could be followed with other licensed antifungal therapies (OLAT). Here, we report the impact of OLAT on the outcome of patients with invasive aspergillosis.
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