617 research outputs found

    Immune dysregulation as a leading principle for lymphoma development in diverse immunological backgrounds

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    Lymphoma is a heterogeneous group of malignancies arising from lymphocytes, which poses a significant challenge in terms of diagnosis and treatment due to its diverse subtypes and underlying mechanisms. This review aims to explore the shared and distinct features of various forms of lymphoma predisposing conditions, with a focus on genetic, immunological and molecular aspects. While diseases such as autoimmune disorders, inborn errors of immunity and iatrogenic immunodeficiencies are biologically and immunologically distinct, each of these diseases results in profound immune dysregulation and a predisposition to lymphoma development. Interestingly, the increased risk is often skewed towards a particular subtype of lymphoma. Patients with inborn errors of immunity in particular present with extreme forms of lymphoma predisposition, providing a unique opportunity to study the underlying mechanisms. External factors such as chronic infections and environmental exposures further modulate the risk of lymphoma development. Common features of conditions predisposing to lymphoma include: persistent inflammation, recurrent DNA damage or malfunctioning DNA repair, impaired tumor surveillance and viral clearance, and dysregulation of fundamental cellular processes such as activation, proliferation and apoptosis. Our growing understanding of the underlying mechanisms of lymphomagenesis provides opportunities for early detection, prevention and tailored treatment of lymphoma development.</p

    A narrative review on spinal deformities in people with cerebral palsy: Measurement, norm values, incidence, risk factors and treatment

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    Spinal deformities are common in people with cerebral palsy (CP), and there is a concern of an increase during the adult ageing period. There is especially a worry about the increase of scoliosis, thoracic hyperkyphosis, lumbar hyperlordosis, spondylolysis and spondylolisthesis incidence, though supporting literature is lacking. Therefore, the aim of this narrative review is to provide a scientific overview of how spinal curvatures should be measured, what the norm values are and the incidence in people with CP, as well as a description of the risk factors and the treatment regimens for these spinal abnormalities. This review can be used as a guideline relevant for a range of clinicians, including orthopaedic and neurosurgeons, radiologists, physiotherapists, and biokineticists, as well as academics

    Binderless zeolite LTA beads with hierarchical porosity for selective CO<sub>2</sub> adsorption in biogas upgrading

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    In the context of CO2 removal from biogas, a series of binderless zeolite LTA adsorbents with a macroscopic bead format (0.5–1.0 mm) and with hierarchical porosity (i.e. with the zeolitic micropores being accessible through meso- and macropores mainly in the 10–100 nm range) was synthesized with a variety of Si/Al ratios (1.2–3.9) using Amberlite IRA-900 anion-exchange resin beads as a hard template. The CO2 and CH4 adsorption capacity of the beads in Na-form with different Si/Al ratios were measured, reaching higher CO2/CH4 selectivity and similar, yet slightly higher CO2 adsorption compared to commercial zeolite LTA pellets containing a binder. Subsequently, one the zeolitic beads was subjected to different degrees of ion-exchange (0–96%) with KCl and then tested in the adsorption of CO2 and CH4. The best performance among all the ion-exchanged beads was achieved with Na58K42-LTA beads, which gave very high CO2/CH4 selectivity (1540). Although essentially no CH4 was adsorbed on these beads, the CO2 adsorption capacity was still substantial (1.9 mmol g−1 at 0.4 bar CO2, i.e. the partial pressure of CO2 in biogas)

    Causal ambiguity and partial orders in event structures

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    Event structure models often have some constraint which ensures that for each\ud system run it is clear what are the causal predecessors of an event (i.e. there is no causal ambiguity). In this contribution we study what happens if we remove\ud such constraints. We define five different partial order semantics that are intentional in the sense that they refer to syntactic aspects of the model. We also define an observational partial order semantics, that derives a partial order from just the event traces. It appears that this corresponds to the so-called early intentional semantics; the other intentional semantics cannot be observationally characterized. We study the equivalences induced by the different partial order definitions, and their interrelations

    Rapid and quantitative detection of homologous and non-homologous recombination events using three oligonucleotide MLPA

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    Embryonic stem (ES) cell technology allows modification of the mouse germline from large deletions and insertions to single nucleotide substitutions by homologous recombination. Identification of these rare events demands an accurate and fast detection method. Current methods for detection rely on Southern blotting and/or conventional PCR. Both the techniques have major drawbacks, Southern blotting is time-consuming and PCR can generate false positives. As an alternative, we here demonstrate a novel approach of Multiplex Ligation-dependent Probe Amplification (MLPA) as a quick, quantitative and reliable method for the detection of homologous, non-homologous and incomplete recombination events in ES cell clones. We have adapted MLPA to detect homologous recombinants in ES cell clones targeted with two different constructs: one introduces a single nucleotide change in the PCNA gene and the other allows for a conditional inactivation of the wild-type PCNA allele. By using MLPA probes consisting of three oligonucleotides we were able to simultaneously detect and quantify both wild-type and mutant alleles

    Binderless SAPO-34 beads for selective CO2 adsorption

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    Selective adsorption of CO2 from biogas allows isolating biomethane, which can then be used as a direct substitute for natural gas. The microporous zeotype SAPO-34 is a suitable material for CO2 adsorption because it can achieve high working capacity at relatively mild regeneration conditions. In industrial applications, adsorbents need to be shaped into a macroscopic format (e.g. beads, pellets) in order to reduce the pressure drop over the adsorption column. Typically, an inert binder is added to the powder to achieve the desired format. In this work, novel hierarchically porous binderless SAPO-34 beads with a diameter in the range 0.7–1.2 mm were synthesised employing an ion-exchange resin as a hard template. The interior of the beads consisted mostly of small SAPO-34 crystals (&lt; 0.3 μm) interconnected to each other and thus generating a network of meso‑ and macropores between them, as demonstrated by XRD and SEM. Around several of the beads, a crystal overgrowth was observed consisting mostly of larger SAPO-34 crystals (1–25 μm). The SAPO beads displayed good CO2 adsorption capacity (3.0 mmol g−1 at 1 bar), which was higher than that of binder-containing SAPO-34 extrudates (2.4 mmol g−1 at 1 bar), but slightly lower compared to SAPO-34 in powder format (3.4 mmol g−1 at 1 bar). Furthermore, the SAPO-34 beads displayed high CO2/CH4 selectivity (8, at partial pressures mimicking biogas, i.e. 0.4 bar CO2 and 0.6 bar CH4) as well as high CO2/N2 selectivity (33, at partial pressures mimicking flue gas, i.e. 0.15 bar CO2 and 0.85 bar N2). Notably, a high CO2 working capacity of 1.8 mmol g−1 was estimated based on the adsorption isotherm between 1 and 0.2 bar, and this value has the potential to be further improved by increasing the adsorption pressure to &gt; 1 bar

    ZSM-5/Silicalite-1 core-shell beads as CO<sub>2</sub> adsorbents with increased hydrophobicity

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    Zeolites are commonly used for selective CO2 adsorption from biogas and flue gas. One of the biggest challenges for zeolites in this application is the presence of water vapour in the raw gas streams. While zeolites with low Si/Al ratio typically display high CO2 adsorption, they are hydrophilic and H2O competes for adsorption on the active sites. On the other hand, zeolites with high Si/Al ratio are hydrophobic, but display lower CO2 adsorption capacities. In order to overcome this limitation and to combine the high CO2 adsorption capacity of low Si/Al zeolites and the hydrophobicity of high Si/Al zeolites into a single material, we designed and synthesized novel core-shell zeolitic beads comprising a ZSM-5 core and a Silicalite-1 shell. Two different strategies were employed to synthesize these macroscopic core-shell beads. In both approaches, the initial step was the synthesis of binderless ZSM-5 beads with hierarchical porosity using resin beads as hard template. In the first strategy, a shell of Silicalite-1 was synthesized on the external surface of the calcined ZSM-5 beads, yielding Sil-ZSM-A core-shell beads (0.84 ± 0.12 mm). In the second strategy, the Silicalite-1 shell was synthesized without first removing the polymeric template from the ZSM-5 beads, resulting in core-shell composite beads that after calcination yielded Sil-ZSM-B core-shell beads (0.73 ± 0.14 mm). Characterization by SEM, XRD, XRF, ICP-AES and N2 physisorption indicated that both Sil-ZSM-A and Sil-ZSM-B beads displayed the desired zeolitic core-shell structure with hierarchical porosity. Both core-shell beads showed the anticipated increase in hydrophobicity. The most promising results were obtained with Sil-ZSM-A beads, which displayed a 40% decrease in H2O adsorption capacity at 20% relative humidity (RH) and a 28% decrease at max RH compared to the parent ZSM-5 beads. At the same time, their CO2 adsorption capacity (1.94 mmol/g at 1 bar) decreased only slightly compared to the parent ZSM-5 beads (2.13 mmol/g at 1 bar). These results indicate that these core-shell beads present the desired combination of the high CO2 adsorption capacity of the ZSM-5 core with the hydrophobicity of the Silicalite-1 shell. This is a promising feature for application in the adsorption of CO2 from water-containing streams.</p

    A systematic review of the effects of single-event multilevel surgery on gait parameters in children with spastic cerebral palsy

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    BACKGROUND: Three-dimensional gait analysis (3DGA) is commonly used to assess the effect of orthopedic single-event multilevel surgery (SEMLS) in children with spastic cerebral palsy (CP). Purpose The purpose of this systematic review is to provide an overview of different orthopedic SEMLS interventions and their effects on 3DGA parameters in children with spastic CP. METHODS: A comprehensive literature search within six databases revealed 648 records, from which 89 articles were selected for the full-text review and 24 articles (50 studies) included for systematic review. The Oxford Centre for Evidence-Based Medicine Scale and the Methodological Index for Non-Randomized Studies (MINORS) were used to appraise and determine the quality of the studies. RESULTS: Except for one level II study, all studies were graded as level III according to the Oxford Centre for Evidence-Based Medicine Scale. The MINORS score for comparative studies (n = 6) was on average 15.7/24, while non-comparative studies (n = 18) scored on average 9.8/16. Nineteen kinematic and temporal-distance gait parameters were selected, and a majority of studies reported improvements after SEMLS interventions. The largest improvements were seen in knee range of motion, knee flexion at initial contact and minimal knee flexion in stance phase, ankle dorsiflexion at initial contact, maximum dorsiflexion in stance and in swing phase, hip rotation and foot progression angles. However, changes in 3DGA parameters varied based on the focus of the SEMLS intervention. DISCUSSION: The current article provides a novel overview of a variety of SEMLS interventions within different SEMLS focus areas and the post-operative changes in 3DGA parameters. This overview will assist clinicians and researchers as a potential theoretical framework to further improve SEMLS techniques within different SEMLS focus groups. In addition, it can also be used as a tool to enhance communication with parents, although the results of the studies can't be generalised and a holistic approach is needed when considering SEMLS in a child with spastic CP

    Molecular characterization and identification of proteins regulated by Hfq in Neisseria meningitidis

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    Hfq is a highly conserved pleiotropically acting prokaryotic RNA-binding protein involved in the post-transcriptional regulation of many stress-responsive genes by small RNAs. In this study, we show that Hfq of the strictly human pathogen Neisseria meningitidis is involved in the regulation of expression of components involved in general metabolic pathways, iron metabolism and virulence. A meningococcal hfq deletion strain (H44/76Δhfq) is impaired in growth in nutrient-rich media and does not grow at all in nutrient-limiting medium. The growth defect was complemented by expression of hfq in trans. Using proteomics, the expression of 28 proteins was found to be significantly affected upon deletion of hfq. Of these, 20 proteins are involved in general metabolism, among them seven iron-responsive genes. Two proteins (PilE, TspA) are involved in adherence to human cells, a step crucial for the onset of disease. One of the differentially expressed proteins, GdhA, was identified as an essential virulence factor for establishment of sepsis in an animal model, studied earlier. These results show that in N. meningitidis Hfq is involved in the regulation of a variety of components contributing to the survival and establishment of meningococcal disease
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