226 research outputs found

    Ground-state energy of biquadratic spin systems (S=3/2) in the (1/z)1-approximation

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    Corrections to the molecular-field ground- state energies of the Heisenberg model with isotropic biquadrati c interactions (spin S = 3= 2) are calculated in the ( 1= z ) 1 -approximation using the diagrammatic technique based on the Wick reduction theorem (z is the numb er of spins interacting with any given spin) . The present results for the antiferri- and antiferromagnetic phases complete the previously obtained data for the antiquadrupolar, ferriand ferromagnetic phases. From among the boundaries between different ground states only that b etw een the antiferri- and antiferromagnetic phases is shifted with respect to its molecular-field value

    Projections, Pseudo-Stopping Times and the Immersion Property

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    Given two filtrations FG\mathbb F \subset \mathbb G, we study under which conditions the F\mathbb F-optional projection and the F\mathbb F-dual optional projection coincide for the class of G\mathbb G-optional processes with integrable variation. It turns out that this property is equivalent to the immersion property for F\mathbb F and G\mathbb G, that is every F\mathbb F-local martingale is a G\mathbb G-local martingale, which, equivalently, may be characterised using the class of F\mathbb F-pseudo-stopping times. We also show that every G\mathbb G-stopping time can be decomposed into the minimum of two barrier hitting times

    Herpes encephalitis presenting as mild aphasia: Case report

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    BACKGROUND: Encephalitis presenting as a change in mental status can be challenging to recognize in the primary care setting. However, early detection via a low threshold of suspicion can be useful, leading in turn to early treatment and improved survival. CASE PRESENTATION: We present a case which we consider relevant to primary care practitioners. The patient in question presented with relatively mild mental status changes, progressing to confusion, dysnomia and delirium over a period of three days. While infection did not appear to be the leading cause on her differential diagnosis, she was found on extensive workup to have encephalitis caused by Herpes Simplex Virus type 1. CONCLUSION: The case is instructive for general practitioners and other clinicians to maintain vigilance for central nervous system (CNS) infections which may present atypically

    Development and initial validation of the bronchiectasis exacerbation and symptom tool (BEST)

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    BACKGROUND: Recurrent bronchiectasis exacerbations are related to deterioration of lung function, progression of the disease, impairment of quality of life, and to an increased mortality. Improved detection of exacerbations has been accomplished in chronic obstructive pulmonary disease through the use of patient completed diaries. These tools may enhance exacerbation reporting and identification. The aim of this study was to develop a novel symptom diary for bronchiectasis symptom burden and detection of exacerbations, named the BEST diary. METHODS: Prospective observational study of patients with bronchiectasis conducted at Ninewells Hospital, Dundee. We included patients with confirmed bronchiectasis by computed tomography, who were symptomatic and had at least 1 documented exacerbation of bronchiectasis in the previous 12\u2009months to participate. Symptoms were recorded daily in a diary incorporating cough, sputum volume, sputum colour, dyspnoea, fatigue and systemic disturbance scored from 0 to 26. RESULTS: Twenty-one patients were included in the study. We identified 29 reported (treated exacerbations) and 23 unreported (untreated) exacerbations over 6-month follow-up. The BEST diary score showed a good correlation with the established and validated questionnaires and measures of health status (COPD Assessment Test, r =\u20090.61, p =\u20090.0037, Leicester Cough Questionnaire, r =\u2009-\u20090.52,p =\u20090.0015, St Georges Respiratory Questionnaire, r =\u20090.61,p <\u20090.0001 and 6\u2009min walk test, r =\u2009-\u20090.46,p =\u20090.037). The mean BEST score at baseline was 7.1 points (SD 2.2). The peak symptom score during exacerbation was a mean of 16.4 (3.1), and the change from baseline to exacerbation was a mean of 9.1 points (SD 2.5). Mean duration of exacerbations based on time for a return to baseline symptoms was 15.3\u2009days (SD 5.7). A minimum clinically important difference of 4 points is proposed. CONCLUSIONS: The BEST symptom diary has shown concurrent validity with current health questionnaires and is responsive at onset and recovery from exacerbation. The BEST diary may be useful to detect and characterise exacerbations in bronchiectasis clinical trials

    Bronchiectasis:an emerging global epidemic

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    Abstract Bronchiectasis has an increasing profile within respiratory medicine. This chronic and irreversible airways disease is common but suffers from a lack of evidenced based therapy for patients and, a lack of understanding of its inherent heterogeneity. Research focused on bronchiectasis must therefore be prioritized if we are to adequately address this evolving clinical problem. This special issue on bronchiectasis focuses on its clinical, microbiological and therapeutic aspects. By bringing together a unique collection of original research and review articles, we hope this issue will showcase international research efforts, encourage future research collaborations and stimulate debate. In doing so, we hope to bring greater attention to the urgent need for sustained investment into focused, dedicated and collaborative research platforms in bronchiectasis, an emerging “global epidemic”

    Bronchiectasis insanity:Doing the same thing over and over again and expecting different results?

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    Bronchiectasis is an increasingly common disease with a significant impact on quality of life and morbidity of affected patients. It is also a very heterogeneous disease with numerous different underlying etiologies and presentations. Most treatments for bronchiectasis are based on low-quality evidence; consequently, no treatments have been approved by the US Food and Drug Administration or the European Medicines Agency for the treatment of bronchiectasis. The last several years have seen numerous clinical trials in which the investigational agent, thought to hold great promise, did not demonstrate a clinically or statistically significant benefit. This commentary will review the likely reasons for these disappointing results and a potential approach that may have a greater likelihood of defining evidence-based treatment for bronchiectasis

    Progressive multifocal leukoencephalopathy in a patient without apparent immunosuppression

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    An 80-year-old man with no history of an immune-compromising disorder was diagnosed with progressive multifocal leukoencephalopathy (PML). He presented with dysphagia and left-sided weakness; magnetic resonance imaging demonstrated marked signal abnormality in the subcortical white matter of the left frontal lobe and in the posterior limb of the right internal capsule. Polymerase chain reaction (PCR) analysis of the cerebrospinal fluid (CSF) was negative for John Cunningham (JC) virus. On brain biopsy, foamy macrophages infiltrating the white matter were identified, staining positive for anti-simian virus 40 antibodies. Postoperatively, PCR for JC viral DNA in the CSF was positive, establishing the diagnosis of PML. Extensive investigation for an occult immunocompromising disorder was negative. The patient's neurologic deficits rapidly increased throughout his hospital stay, and he died 3.5 months after his diagnosis

    Development of Drugs for Nontuberculous Mycobacterial Disease:Clinicians’ Interpretation of a US Food and Drug Administration Workshop

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    The US Food and Drug Administration convened a workshop to discuss clinical trial design challenges and considerations related to the treatment of nontuberculous mycobacterial pulmonary disease, to include topics such as clinical trial end points, duration, and populations. The clinicians participating in the meeting provide here their interpretation of the discussion, which included US Food and Drug Administration and industry representatives. The treatment of nontuberculous mycobacterial pulmonary disease typically includes multiple antibiotics for a prolonged period and can be difficult to tolerate; there is a great need for new treatment options. Most individuals have a microbiologic response to therapy, but data correlating decreasing bacillary load with patient-reported outcomes or measured functional improvement are lacking. Accordingly, trial designs for new therapeutic agents should incorporate both microbiologic and clinical outcome measures and select appropriate study candidates with capacity for measurable change of such outcome measures. The need for shorter study designs, early primary end points, and placebo control arms was highlighted during the workshop
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