9,324 research outputs found
Drying of enzyme immobilized on eco-friendly supports
Endophytic fungus Cercospora kikuchii lipase was immobilized on agroindustrial by-products and dried by oven, freeze and spray drying. Spray drying showed the best performance regarding the drying technologies evaluated. Microcrystalline cellulose and rice husk showed the best result since they retained almost 100% of lipase activity after drying. Immobilized derivatives obtained had decreased enzyme activity (≈ 30.0%) during a storage period of six months; and retained an average of 50.0% of the initial activity after five reuse cycles. Water content in immobilized derivatives varied between 4.2 and 6.1% and the water activities ranged from 0.14 to 0.30.Key words: Enzyme immobilization, drying, Cercospora kikuchii, agricultural by-products
Understanding drought dynamics during dry season in Eastern Northeast Brazil
Eastern Northeast Brazil (ENEB) generally experiences a high variability in precipitation in the dry season, with amplitudes that can overcome 500mm. The understanding of this variability can help in mitigating the socio-economic issues related to the planning and management of water resources this region, which is highly vulnerable to drought. This work aims to assess spatio-temporal variability of precipitation during the dry season and investigate the relationships between climate phenomena and drought events in the ENEB, using univariate (Spearman correlation) and multivariate statistical techniques, such as Principal Component Analysis, Cluster Analysis, and Maximum Covariance Analysis. The results indicate that the variability of precipitation in the dry season can be explained mainly (62%) by local physical conditions and climate conditions have a secondary contribution. Further analysis of the larger anomalous events suggests that the state of Atlantic and Pacific oceans can govern the occurrence of those events, and the conditions of Atlantic Ocean can be considered a potential modulator of anomalous phenomena of precipitation in ENEB
Defining hereditary alpha-tryptasemia as a risk/modifying factor for anaphylaxis: are we there yet?
Hereditary a-tryptasemia (HaT) is a common autosomal dominant genet-ic trait with variable penetrance associated with increased serum baseline tryptase (SBT) levels. Clinical manifestations may range from an absence of symptoms to overtly severe and recurrent anaphylaxis. Symptoms have been claimed to result from excessive activation of EGF-like module -con-taining mucin-like hormone receptor-like 2 (EMR2) and protease activat-ed receptor 2 (PAR-2) receptors by a/13-tryptase heterotetramers. Herein, we aimed to review the evidence on whether HaT can be considered a hereditary risk factor or a modifying factor for anaphylaxis. Increased SBT levels have been linked to an increased risk of anaphylaxis. Likewise, recent studies have shown that HaT might be associated with a higher risk of developing anaphylaxis and more severe anaphylaxis. The same has also been shown for patients with clonal mast cell disorders, in whom the co-existence of HaT might lead to a greater propensity for se-vere, potentially life-threatening anaphylaxis. However, studies leading to such conclusions are generally limited in sample size, while other studies have shown opposing results. As such, further studies investigating the po-tential association of HaT with anaphylaxis caused by different triggers, and different severity grades, in both patients with clonal mast cell activa-tion syndromes and the general population are still needed
Perioperative corticosteroids for preventing complications following facial plastic surgery
COVID-19 Vaccination Is Safe among Mast Cell Disorder Patients, under Adequate Premedication
Reported cases of anaphylaxis following COVID-19 vaccination raised concerns about the safety of these vaccines, namely in patients suffering from clonal mast cell (MC) disorders—a het-erogenous group of disorders in which patients may be prone to anaphylaxis caused by vaccination. This study aimed to assess the safety of COVID-19 vaccines in patients with clonal MC disorders. We performed an ambidirectional cohort study with 30 clonal MC disorder patients (n = 26 in the prospective arm and n = 4 in the retrospective arm), that were submitted to COVID-19 vaccination. Among these, 11 (37%) were males, and median age at vaccination date was 41 years (range: 5 y to 76 y). One patient had prior history of anaphylaxis following vaccination. Those in the prospective arm received a premedication protocol including H1-and H2-antihistamines and montelukast, while those in the retrospective arm did not premedicate. Overall, patients received a total of 81 doses, 73 under premedication and 8 without premedication. No MC activation symptoms were reported. COVID-19 vaccination seems to be safe in patients with clonal mast cell disorders, including those with prior anaphylaxis following vaccination. Robust premedication protocols may allow for vaccination in ambulatory settings. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.This research received no external funding. Article processing charges were paid by the IAPorto Research Center
Mycobacterial infection-induced miR-206 inhibits protective neutrophil recruitment via the CXCL12/CXCR4 signalling axis
Pathogenic mycobacteria actively dysregulate protective host immune signalling pathways during infection to drive the formation of permissive granuloma microenvironments. Dynamic regulation of host microRNA (miRNA) expression is a conserved feature of mycobacterial infections across host-pathogen pairings. Here we examine the role of miR-206 in the zebrafish model of Mycobacterium marinum infection, which allows investigation of the early stages of granuloma formation. We find miR-206 is upregulated following infection by pathogenic M. marinum and that antagomir-mediated knockdown of miR-206 is protective against infection. We observed striking upregulation of cxcl12a and cxcr4b in infected miR-206 knockdown zebrafish embryos and live imaging revealed enhanced recruitment of neutrophils to sites of infection. We used CRISPR/Cas9-mediated knockdown of cxcl12a and cxcr4b expression and AMD3100 inhibition of Cxcr4 to show that the enhanced neutrophil response and reduced bacterial burden caused by miR-206 knockdown was dependent on the Cxcl12/Cxcr4 signalling axis. Together, our data illustrate a pathway through which pathogenic mycobacteria induce host miR-206 expression to suppress Cxcl12/Cxcr4 signalling and prevent protective neutrophil recruitment to granulomas
A Bright Spatially-Coherent Compact X-ray Synchrotron Source
Each successive generation of x-ray machines has opened up new frontiers in
science, such as the first radiographs and the determination of the structure
of DNA. State-of-the-art x-ray sources can now produce coherent high brightness
keV x-rays and promise a new revolution in imaging complex systems on nanometre
and femtosecond scales. Despite the demand, only a few dedicated synchrotron
facilities exist worldwide, partially due the size and cost of conventional
(accelerator) technology. Here we demonstrate the use of a recently developed
compact laser-plasma accelerator to produce a well-collimated,
spatially-coherent, intrinsically ultrafast source of hard x-rays. This method
reduces the size of the synchrotron source from the tens of metres to
centimetre scale, accelerating and wiggling a high electron charge
simultaneously. This leads to a narrow-energy spread electron beam and x-ray
source that is >1000 times brighter than previously reported plasma wiggler and
thus has the potential to facilitate a myriad of uses across the whole spectrum
of light-source applications.Comment: 5 pages, 4 figure
A Sparse Stress Model
Force-directed layout methods constitute the most common approach to draw
general graphs. Among them, stress minimization produces layouts of
comparatively high quality but also imposes comparatively high computational
demands. We propose a speed-up method based on the aggregation of terms in the
objective function. It is akin to aggregate repulsion from far-away nodes
during spring embedding but transfers the idea from the layout space into a
preprocessing phase. An initial experimental study informs a method to select
representatives, and subsequent more extensive experiments indicate that our
method yields better approximations of minimum-stress layouts in less time than
related methods.Comment: Appears in the Proceedings of the 24th International Symposium on
Graph Drawing and Network Visualization (GD 2016
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