123 research outputs found

    Permeability sets the linear path instability of buoyancy-driven disks

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    The prediction of trajectories of buoyancy-driven objects immersed in a viscous fluid is a key problem in fluid dynamics. Simple-shaped objects, such as disks, present a great variety of trajectories, ranging from zig-zag to tumbling and chaotic motions. Yet, similar studies are lacking when the object is permeable. We perform a linear stability analysis of the steady vertical path of a thin permeable disk, whose flow through the microstructure is modelled via a stress-jump model based on homogenization theory. The relative velocity of the flow associated with the vertical steady path presents a recirculation region detached from the body, which shrinks and eventually disappears as the disk becomes more permeable. In analogy with the solid disk, one non-oscillatory and several oscillatory modes are identified and found to destabilize the fluid-solid coupled system away from its straight trajectory. Permeability progressively filters out the wake dynamics in the instability of the steady vertical path. Modes dominated by wake oscillations are first stabilized, followed by those characterized by weaker, or absent, wake oscillations, in which the wake is typically a tilting induced by the disk inclined trajectory. For sufficiently large permeabilities, the disk first undergoes a non-oscillatory divergence instability, which is expected to lead to a steady oblique path with a constant disk inclination, in the nonlinear regime. A further permeability increase reduces the unstable range of all modes until quenching of all linear instabilities

    Sublingual immunotherapy: administration, dosages, use

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    Allergen extracts for sublingual immunotherapy (SLIT) are currently marketed by several manufacturers, with administration schedules and amount of allergen(s) quite variable in the different products, although almost all are standardized biologically or immunologically. The allergen extracts for SLIT are available in two main pharmaceutical forms: solution to be delivered by drop-counters, pre-dosed actuators (mini-pumps) or disposable single-dose vials; tablets with appropriate composition that allows a slow (1-2 minutes) dissolution in the mouth in contact with saliva. In Europe, SLIT is prescribed in general for one or a few allergens, and mixtures are less used, though there is no immunological contraindication to give multiple allergens. SLIT traditionally involves a build-up phase and a maintenance phase with the top dose. The build-up phase has usually the duration of 4 - 6 weeks. The patient must start with the lowest concentration and gradually increase, using the different dosage preparations, until the maintenance dose is reached. Rush and ultra-rush inductions have been introduced, based on the safety profile of SLIT that is very favorable. For these reasons it has been suggested that an updosing phase maybe even not necessary. The no-updosing approach would result in a treatment that is more patient-friendly and convenient to manage. Indeed, the most recent randomized trials were performed with the no-updosing regimen and their results in term of safety were as favorable as the studies performed with the traditional updosing approach. The currently recommended duration of SLIT is comprised between 3 and 4 years depending on the clinical response in single patients

    Physical exercise in major depression: Reducing the mortality gap while improving clinical outcomes

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    Major depression shortens life while the effectiveness of frontline treatments remains modest. Exercise has been shown to be effective both in reducing mortality and in treating symptoms of major depression, but it is still underutilized in clinical practice, possibly due to prevalent misperceptions. For instance, a common misperception is that exercise is beneficial for depression mostly because of its positive effects on the body (\u201cfrom the neck down\u201d), whereas its effectiveness in treating core features of depression (\u201cfrom the neck up\u201d) is underappreciated. Other long-held misperceptions are that patients suffering from depression will not engage in exercise even if physicians prescribe it, and that only vigorous exercise is effective. Lastly, a false assumption is that exercise may be more harmful than beneficial in old age, and therefore should only be recommended to younger patients. This narrative review summarizes relevant literature to address the aforementioned misperceptions and to provide practical recommendations for prescribing exercise to individuals with major depression

    Italian intersociety consensus on management of long covid in children

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    Background: Two sequelae of pediatric COVID-19 have been identified, the multisystem inflammatory syndrome in children (MIS-C) and the long COVID. Long COVID is much less precisely defined and includes all the persistent or new clinical manifestations evidenced in subjects previously infected by SARS-CoV-2 beyond the period of the acute infection and that cannot be explained by an alternative diagnosis. In this Intersociety Consensus, present knowledge on pediatric long COVID as well as how to identify and manage children with long COVID are discussed. Main findings: Although the true prevalence of long COVID in pediatrics is not exactly determined, it seems appropriate to recommend evaluating the presence of symptoms suggestive of long COVID near the end of the acute phase of the disease, between 4 and 12 weeks from this. Long COVID in children and adolescents should be suspected in presence of persistent headache and fatigue, sleep disturbance, difficulty in concentrating, abdominal pain, myalgia or arthralgia. Persistent chest pain, stomach pain, diarrhea, heart palpitations, and skin lesions should be considered as possible symptoms of long COVID. It is recommended that the primary care pediatrician visits all subjects with a suspected or a proven diagnosis of SARS-CoV-2 infection after 4 weeks to check for the presence of symptoms of previously unknown disease. In any case, a further check-up by the primary care pediatrician should be scheduled 3 months after the diagnosis of SARS-CoV-2 infection to confirm normality or to address emerging problems. The subjects who present symptoms of any organic problem must undergo a thorough evaluation of the same, with a possible request for clinical, laboratory and / or radiological in-depth analysis in case of need. Children and adolescents with clear symptoms of mental stress will need to be followed up by existing local services for problems of this type. Conclusions: Pediatric long COVID is a relevant problem that involve a considerable proportion of children and adolescents. Prognosis of these cases is generally good as in most of them symptoms disappear spontaneously. The few children with significant medical problems should be early identified after the acute phase of the infection and adequately managed to assure complete resolution. A relevant psychological support for all the children during COVID-19 pandemic must be organized by health authorities and government that have to treat this as a public health issue

    Nationwide survey on the management of pediatric pharyngitis in Italian emergency units

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    Background: Acute pharyngitis is a frequent reason for primary care or emergency unit visits in children. Most available data on pharyngitis management come from primary care studies that demonstrate an underuse of microbiological tests, a tendency to over-prescribe antibiotics and a risk of antimicrobial resistance increase. However, a comprehensive understanding of acute pharyngitis management in emergency units is lacking. This study aimed to investigate the frequency of rapid antigen test use to diagnose acute pharyngitis, as well as other diagnostic approaches, the therapeutic attitude, and follow-up of children with this condition in the emergency units. Methods: A multicentric national study was conducted in Italian emergency departments between April and June 2022. Results: A total of 107 out of 131 invited units (response rate 82%), participated in the survey. The results showed that half of the units use a scoring system to diagnose pharyngitis, with the McIsaac score being the most commonly used. Most emergency units (56%) were not provided with a rapid antigen diagnostic test by their hospital, but the test was more frequently available in units visiting more than 10,000 children yearly (57% vs 33%, respectively, p = 0.02). Almost half (47%) of the units prescribe antibiotics in children with pharyngitis despite the lack of microbiologically confirmed cases of Group A β-hemolytic streptococcus. Finally, about 25% of units prescribe amoxicillin-clavulanic acid to treat Group A β-hemolytic streptococcus pharyngitis. Conclusions: The study sheds light on the approach to pharyngitis in emergency units, providing valuable information to improve the appropriate management of acute pharyngitis in this setting. The routinary provision of rapid antigen tests in the hospitals could enhance the diagnostic and therapeutic approach to pharyngitis

    Clinical spectrum time course in non-Asian patients positive for anti-MDA5 antibodies

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    Objectives: To define the clinical spectrum time-course and prognosis of non-Asian patients positive for anti-MDA5 antibodies. Methods: We conducted a multicentre, international, retrospective cohort study. Results: 149 anti-MDA5 positive patients (median onset age 53 years, median disease duration 18 months), mainly females (100, 67%), were included. Dermatomyositis (64, 43%) and amyopathic dermatomyositis (47, 31%), were the main diagnosis; 15 patients (10%) were classified as interstitial pneumonia with autoimmune features (IPAF) and 7 (5%) as rheumatoid arthritis. The main clinical findings observed were myositis (84, 56%), interstitial lung disease (ILD) (108, 78%), skin lesions (111, 74%), and arthritis (76, 51%). The onset of these manifestations was not concomitant in 74 cases (50%). Of note, 32 (21.5%) patients were admitted to the intensive care unit for rapidly progressive-ILD, which occurred in median 2 months from lung involvement detection, in the majority of cases (28, 19%) despite previous immunosuppressive treatment. One-third of patients (47, 32% each) was ANA and anti-ENA antibodies negative and a similar percentage was anti-Ro52 kDa antibodies positive. Non-specific interstitial pneumonia (65, 60%), organising pneumonia (23, 21%), and usual interstitial pneumonia-like pattern (14, 13%) were the main ILD patterns observed. Twenty-six patients died (17%), 19 (13%) had a rapidly progressive-ILD. Conclusions: The clinical spectrum of the anti-MDA5 antibodies-related disease is heterogeneous. Rapidly-progressive ILD deeply impacts the prognosis also in non-Asian patients, occurring early during the disease course. Anti-MDA5 antibody positivity should be considered even when baseline autoimmune screening is negative, anti-Ro52 kDa antibodies are positive, and radiology findings show a NSIP pattern

    Influence of antisynthetase antibodies specificities on antisynthetase syndrome clinical spectrum time course

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    Antisynthetase syndrome (ASSD) is a rare clinical condition that is characterized by the occurrence of a classic clinical triad, encompassing myositis, arthritis, and interstitial lung disease (ILD), along with specific autoantibodies that are addressed to different aminoacyl tRNA synthetases (ARS). Until now, it has been unknown whether the presence of a different ARS might affect the clinical presentation, evolution, and outcome of ASSD. In this study, we retrospectively recorded the time of onset, characteristics, clustering of triad findings, and survival of 828 ASSD patients (593 anti-Jo1, 95 anti-PL7, 84 anti-PL12, 38 anti-EJ, and 18 anti-OJ), referring to AENEAS (American and European NEtwork of Antisynthetase Syndrome) collaborative group's cohort. Comparisons were performed first between all ARS cases and then, in the case of significance, while using anti-Jo1 positive patients as the reference group. The characteristics of triad findings were similar and the onset mainly began with a single triad finding in all groups despite some differences in overall prevalence. The "ex-novo" occurrence of triad findings was only reduced in the anti-PL12-positive cohort, however, it occurred in a clinically relevant percentage of patients (30%). Moreover, survival was not influenced by the underlying anti-aminoacyl tRNA synthetase antibodies' positivity, which confirmed that antisynthetase syndrome is a heterogeneous condition and that antibody specificity only partially influences the clinical presentation and evolution of this condition
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