832 research outputs found
Acute severe asthma treated by mechanical ventilation: a comparison of the changing characteristics over a 17 yr period
AbstractRecorded cases of asthma have increased in recent years. It is unclear, however, whether this apparent increase in prevalence is accompanied by an increase in severity of the disorder. One potential measure of asthma severity is the requirement for mechanical ventilation. This paper examines those patients ventilated for severe asthma in a district general hospital over a 17 yr period. Since the methods used to assess asthma attacks and the criteria for instituting mechanical ventilation in this hospital did not alter between 1973 and 1992 (Jones criteria), it was possible to compare directly characteristics of all ventilated patients during the study period.The comparison showed that there was a significant increase between the two study periods in the number of patients who required mechanical ventilation. Moreover, in the more recent period both the subjective speed of onset of the asthma attack and the objective time between admission and ventilation were significantly shorter. However, despite this increase in asthma severity the mortality and morbidity in the more recent study period were lower.Overall the results of this study support the view that, in the population served by our district general hospital, asthma has increased in severity. This increased severity is indicated by an increase in the number of patients requiring mechanical ventilation and in the rapidity with which attacks evolved. However, for patients in whom ventilation was required, improved care has lowered both morbidity and mortality
A limited seed bank in both natural and degraded tropical peat swamp forest: the implications for restoration
Carbon-rich tropical peat swamp forests (PSFs) are being degraded at an alarming rate. In response to national and global agendas, landscape-scale PSF restoration is underway, although supporting knowledge of PSF ecosystem restoration ecology remains limited. Seed banks are usually an important source of natural regeneration and crucial in post-degradation forest recovery, even in the humid tropics where reduced seed dormancy leads to typically smaller seed banks than in temperate regions. It has been assumed that PSF degradation reduces the seed bank, limiting natural regeneration, but this has not previously been investigated explicitly. This study of PSF in Central Kalimantan explored seed bank prevalence and regenerative capacity across five forest zones (FZs): degraded, open canopy disturbed, edge, closed canopy disturbed and natural. Numbers and species of seeds and seedlings were recorded from surface peat samples collected from each FZ over one year. Seed density, averaged across FZs, was 41 seeds m-2; total species number was 11; and seedling density was 16.0–73.6 m-2 depending on FZ. These values were much lower than for other forests in this region. There was little difference in seed bank size between natural and degraded FZs, and only the forest edge showed higher than expected seed bank regenerative capability. Overall, our results suggest that seed banks are not of high importance in tropical PSF regeneration, either before or after degradation. These findings are discussed from the perspective of successional traits in different species and their relevance to ecosystem restoration
Total joint replacement in sub-Saharan Africa:a systematic review
Outcomes of arthroplasty in sub-Saharan Africa are not widely reported. To our knowledge, this systematic review is the first to explore this topic. Scopus, EMBASE, Medline and PubMed databases were searched, utilising MeSH headings and Boolean search strategies. All papers from South Africa were excluded. Twelve papers reporting 606 total hip replacements (THRs) and 763 total knee replacements (TKRs) were included. Avascular necrosis was the most common indication for THR, whereas osteoarthritis was the main indication for TKR. HIV prevalence of up to 33% was seen. Improvements were seen in patient-reported outcome measures in both THR and TKR. The dislocation rate in THR was 1.6%. The deep infection rate was 1.6% for TKRs and 0.5% for THRs. Positive results were reported, with comparable complications to high-income countries. However, there is likely to be significant reporting bias and the introduction of mandatory registries would enable more accurate monitoring across the region
Phonons and specific heat of linear dense phases of atoms physisorbed in the grooves of carbon nanotube bundles
The vibrational properties (phonons) of a one-dimensional periodic phase of
atoms physisorbed in the external groove of the carbon nanotube bundle are
studied. Analytical expressions for the phonon dispersion relations are
derived. The derived expressions are applied to Xe, Kr and Ar adsorbates. The
specific heat pertaining to dense phases of these adsorbates is calculated.Comment: 4 PS figure
Vegetation control on soil organic matter dynamics
Soil organic matter (SOM) formation is one of the least understood steps of the global carbon cycle. An example is uncertainty around the role of plant communities in regulating SOM formation and turnover. Here we took advantage of the highly controlled conditions at the San Dimas lysimeter installation to quantify the influence of oak and pine vegetation on SOM dynamics. SOM turnover rates, estimated using total C and C-14 content of litter and physically separable soil fractions, were faster under oak than under pine. In contrast to the rapid turnover for the oak litter (<2 years), the delay in litter incorporation into the mineral soil under pine was a controlling factor of SOM fluxes. (C) 2001 Published by Elsevier Science Ltd
Proteomic analysis of FOXP proteins reveals interactions between cortical transcription factors associated with neurodevelopmental disorders
FOXP transcription factors play important roles in neurodevelopment, but little is known about how their transcriptional activity is regulated. FOXP proteins cooperatively regulate gene expression by forming homo- and hetero-dimers with each other. Physical as
BRAF Rearrangements and BRAF V600E Mutations Are Seen in a Subset of Pancreatic Carcinomas With Acinar Differentiation.
Comprehensive genomic profiling has demonstrated that approximately 20% of pancreatic carcinomas with acinar differentiation harbor potentially targetable BRAF fusions that activate the MAPK pathway.
To validate the above finding by BRAF break-apart fluorescence in situ hybridization (FISH) in a large series of pure acinar cell carcinomas (ACCs), evaluate tumors for the presence of BRAF V600E mutations, and compare clinicopathologic features of tumors with BRAF rearrangements with those without.
Thirty cases of pure ACC and 6 cases of mixed acinar-neuroendocrine carcinoma (ACC-NEC) were retrieved. A break-apart FISH probe was used to detect BRAF rearrangements. Immunohistochemistry for BRAF V600E was performed.
BRAF rearrangements by FISH were found in 6 of 36 cases (17%), 5 of which were pure ACC and 1 was a mixed ACC-NEC. Follow-up was available in 29 of 36 (81%). The median survival was 22 months for BRAF-rearranged cases and 16 months for BRAF-intact cases; the 2-year overall survival was 50% for BRAF-rearranged cases and 35% for BRAF-intact cases. No significant clinicopathologic differences were identified in cases with BRAF rearrangement compared with those without BRAF rearrangement. BRAF V600E mutation was identified in 2 of 34 cases (6%), both of which were pure ACC and were BRAF-intact by FISH.
This study supports the finding that BRAF rearrangements are present in approximately 20% of cases and identified BRAF V600E mutations in approximately 5% of cases. These cases may benefit from targeted therapy
Dupilumab reduces systemic corticosteroid use and sinonasal surgery rate in CRSwNP
BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease with a high symptom burden and poor quality of life. Treatment options include recurrent surgeries and/or frequent systemic corticosteroids (SCS). Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4 and interleukin-13, key drivers of type 2-mediated inflammation. We report results of pooled analyses from 2 randomised, double-blind, placebo-controlled phase 3 studies (SINUS 24 [NCT02912468]; SINUS-52 [NCT02898454]) to evaluate dupilumab effect versus placebo in adults with CRSwNP with/without SCS use and sinonasal surgery.
METHODOLOGY: SINUS-24 patients were randomised 1:1 to subcutaneous dupilumab 300 mg (n=143) or placebo (n=133) every 2 weeks (q2w) for 24 weeks. SINUS-52 patients were randomised 1:1:1 to 52 weeks of subcutaneous dupilumab 300 mg q2w (n=150), 24 weeks q2w followed by 28 weeks of dupilumab 300 mg every 4 weeks (n=145) or 52 weeks of placebo q2w (n=153).
RESULTS: Dupilumab reduced the number of patients undergoing sinonasal surgery (82.6%), the need for in-study SCS use (73.9%), and SCS courses (75.3%). Significant improvements were observed with dupilumab vs placebo regardless of prior sinonasal surgery or SCS use in nasal polyp, nasal congestion, Lund-MacKay, and Sinonasal Outcome Test (22-items) scores, and the University of Pennsylvania Smell Identification Test.
CONCLUSIONS: Dupilumab demonstrated significant improvements in disease signs and symptoms and reduced the need for sino-nasal surgery and SCS use versus placebo in patients with severe CRSwNP, regardless of SCS use in the previous 2 years, or prior sinonasal surgery
Primordialists and Constructionists: a typology of theories of religion
This article adopts categories from nationalism theory to classify theories of religion. Primordialist explanations are grounded in evolutionary psychology and emphasize the innate human demand for religion. Primordialists predict that religion does not decline in the modern era but will endure in perpetuity. Constructionist theories argue that religious demand is a human construct. Modernity initially energizes religion, but subsequently undermines it. Unpacking these ideal types is necessary in order to describe actual theorists of religion. Three distinctions within primordialism and constructionism are relevant. Namely those distinguishing: a) materialist from symbolist forms of constructionism; b) theories of origins from those pertaining to the reproduction of religion; and c) within reproduction, between theories of religious persistence and secularization. This typology helps to make sense of theories of religion by classifying them on the basis of their causal mechanisms, chronology and effects. In so doing, it opens up new sightlines for theory and research
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