bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thunderstorm outflows preceding epidemics of asthma during spring and summer
Authors: Marks G B , Colquhoun J R , Girgis S T , Koski M Hjelmroos , Treloar A B A , Hansen P , Downs S H , Car N G 
Published: July 2021

BACKGROUNDA study was undertaken to assess the importance of thunderstorms as a cause of epidemics of asthma exacerbations and to investigate the underlying mechanism.METHODSA case control study was performed in six towns in south eastern Australia. Epidemic case days (n = 48) and a random sample of control days (n = 191) were identified by reference to the difference between the observed and expected number of emergency department attendances for asthma. The occurrence of thunderstorms, their associated outflows and cold fronts were ascertained, blind to case status, for each of these days. In addition, the relation of hourly pollen counts to automatic weather station data was examined in detail for the period around one severe epidemic of asthma exacerbations. The main outcome measure was the number of epidemics of asthma exacerbations.RESULTSThunderstorm outflows were detected on 33% of epidemic days and only 3% of control days (odds ratio 15.0, 95% confidence interval 6.0 to 37.6). The association was strongest in late spring and summer. Detailed examination of one severe epidemic showed that its onset coincided with the arrival of the thunderstorm outflow and a 4–12 fold increase in the ambient concentration of grass pollen grains.CONCLUSIONSThese findings are consistent with the hypothesis that some epidemics of exacerbations of asthma are caused by high concentrations of allergenic particles produced by an outflow of colder air, associated with the downdraught from a thunderstorm, sweeping up pollen grains and particles and then concentrating them in a shallow band of air at ground level. This is a common cause of exacerbations of asthma during the pollen season.
A survey of nocturnal hypoxaemia and health related quality of life in patients with cryptogenic fibrosing alveolitis
Authors: Clark M , Cooper B , Singh S , Cooper M , Carr A , Hubbard R 
Published: July 2021

BACKGROUNDA survey of overnight oximetry was conducted to estimate the prevalence of nocturnal hypoxaemia in patients with cryptogenic fibrosing alveolitis and to establish whether nocturnal hypoxaemia is related to quality of life.METHODSAll patients with cryptogenic fibrosing alveolitis attending Nottingham City Hospital were invited to enter the study. Spirometric measurements and capillary blood gas tensions were obtained and overnight oxygen saturation was recorded at home. Quality of life was assessed using the Short Form-36, Chronic Respiratory Questionnaire, Hospital Anxiety Depression Scale, and Epworth Sleepiness Score questionnaires.RESULTSSixty seven eligible patients were identified and 50 agreed to enter the study, although two were subsequently excluded because they already used oxygen overnight. In the remaining 48 the mean (SD) overnight oxygen saturation (Sao2) was 92.5 (4.3)% and the median number of dips greater than 4% per hour was 2.3 (interquartile range 1.5–5.3). Daytime oxygen level predicted mean overnight Sao2(1.94%/kPa, 95% CI 1.22 to 2.66, p<0.001) but percentage predicted forced vital capacity (FVC) did not (0.018%/% predicted FVC, 95% CI –0.04 to 0.08, p=0.5). Nocturnal hypoxaemia was associated with decreased energy levels and impaired daytime social and physical functioning, and these effects were independent of FVC.CONCLUSIONSNocturnal hypoxaemia is common in patients with cryptogenic fibrosing alveolitis and may have an impact on health related quality of life.
Reduction in motor vehicle collisions following treatment of sleep apnoea with nasal CPAP
Authors: George C F P 
Published: July 2021

BACKGROUNDPatients with untreated obstructive sleep apnoea (OSA) have increased motor vehicle collisions (MVCs). When successfully treated, they report improved driving and fewer mishaps, but there are few objective data to confirm this. A study was therefore undertaken to examine actual MVC data in a large group of patients with OSA before and after treatment with continuous positive airway pressure (CPAP) compared with a control group matched for age, sex, and type of driver's licence (commercial or non-commercial).METHODSTwo hundred and ten patients of mean (SD) age 52 (11) years, body mass index (BMI) 35.5 (10) kg/m2, apnoea/hypopnoea index (AHI) 54 (29) events/h were treated with CPAP for at least 3 years. MVC records were obtained from the Ontario Ministry of Transportation (MTO) database for patients and an equal number of randomly selected control drivers. MVC rates were compared for 3 years before and after CPAP therapy for patients and for the corresponding time frames for controls.RESULTSUntreated patients with OSA had more MVCs than controls (mean (SD) MVCs/driver/year 0.18 (0.29) v 0.06 (0.17), p<0.001). Following CPAP treatment the number of MVCs/driver/year fell to normal (0.06 (0.17)) while, in controls, the MVC rate was unchanged over time (0.06 (0.17) v 0.07 (0.18), p=NS). Thus, the change in MVCs over time between the groups was very significant (change = –0.12 (95% CI –0.17 to –0.06), p<0.001)). The MVC rate in untreated patients (n=27) remained high over time. Driving exposure was not different following CPAP.CONCLUSIONSThe risk of MVCs due to OSA is removed when patients are treated with CPAP. As such, any restrictions on driving because of OSA could be safely removed after treatment.
A biological staging model for operable non-small cell lung cancer
Authors: Cox G , Jones J L , Andi A , Waller D A , O'Byrne K J 
Published: July 2021

BACKGROUNDCurrently the best prognostic index for operable non-small cell lung cancer (NSCLC) is the TNM staging system. Molecular biology holds the promise of predicting outcome for the individual patient and identifying novel therapeutic targets. Angiogenesis, matrix metalloproteinases (MMP)-2 and -9, and the erb/HER type I tyrosine kinase receptors are all implicated in the pathogenesis of NSCLC.METHODSA retrospective analysis of 167 patients with resected stage I–IIIa NSCLC and >60 days postoperative survival with a minimum follow up of 2 years was undertaken. Immunohistochemical analysis was performed on paraffin embedded sections for the microvessel marker CD34, MMP-2 and MMP-9, EGFR, and c-erbB-2 to evaluate the relationships between and impact on survival of these molecular markers.RESULTSTumour cell MMP-9 (HR 1.91 (1.23–2.97)), a high microvessel count (HR 1.97 (1.28–3.03)), and stage (stage II HR 1.44 (0.87–2.40), stage IIIa HR 2.21 (1.31–3.74)) were independent prognostic factors. Patients with a high microvessel count and tumour cell MMP-9 expression had a worse outcome than cases with only one (HR 1.68 (1.04–2.73)) or neither (HR 4.43 (2.29–8.57)) of these markers. EGFR expression correlated with tumour cell MMP-9 expression (p<0.001). Immunoreactivity for both of these factors within the same tumour was associated with a poor prognosis (HR 2.22 (1.45–3.41)).CONCLUSIONAngiogenesis, EGFR, and MMP-9 expression provide prognostic information independent of TNM stage, allowing a more accurate outcome prediction for the individual patient. The development of novel anti-angiogenic agents, EGFR targeted therapies, and MMP inhibitors suggests that target specific adjuvant treatments may become a therapeutic option in patients with resected NSCLC.
Prevalence of asthma among schoolchildren in Patras, Greece: three surveys over 20 years
Authors: Anthracopoulos M , Karatza A , Liolios E , Triga M , Triantou K , Priftis K 
Published: July 2021

BACKGROUNDThe aim of the present study was to compare the prevalence of asthma among schoolchildren in 1978, 1991, and 1998 in Patras, Greece.METHODSThe study populations of the three comparable cross sectional surveys comprised third and fourth grade public school children in Patras, Greece. Sample sizes in 1978, 1991, and 1998 were 3735, 2952 and 3397 children and response rates were 80.4%, 81.9%, and 90.6%, respectively. Prevalence of current, non-current, and lifetime asthma or recurrent wheezing was determined by parental questionnaire. Personal communication with the parents of asthmatic children in 1991 and 1998 provided data on lost schooldays.RESULTSPrevalence rates of current asthma or wheezing in 1978, 1991, and 1998 were 1.5%, 4.6%, and 6.0%, respectively (1978–91: p=0.01, 1991–98: p=0.02, 1978–98: p=0.03). Lifetime prevalences of asthma or wheezing in 1991 and 1998 were 8.0% and 9.6%, respectively (p=0.03). Current diagnosed asthma increased proportionally to diagnosed wheezing during 1991–98. The number of schooldays lost in the previous 2 years because of asthma did not change (p>0.1) between 1991 (0.31 per child) and 1998 (0.34 per child).CONCLUSIONSOur results support a true increase in the prevalence of current and lifetime asthma in the last 20 years among pre-adolescent children in Patras, Greece.
Effect of nebulised l- and d-arginine on exhaled nitric oxide in steroid naive asthma
Authors: Chambers D C , Ayres J G 
Published: July 2021

BACKGROUNDNitric oxide (NO) is a product of the enzyme nitric oxide synthase (NOS) and is found in normal and asthmatic human airways. The administration ofl-arginine results in an increase in airway NO production in asthmatic subjects. This is thought to occur becausel-arginine is the substrate for NOS. However, studies in the systemic vasculature suggest that other mechanisms may be responsible.METHODSEight patients with steroid naive asthma each received 2.5 gl-arginine, 2.5 gd-arginine, and 2.0% saline by ultrasonic nebuliser on separate days in a randomised, single blind manner. Exhaled NO was measured by chemiluminescence and spirometric tests were performed before and for 3 hours after each administration. The mean concentration of NO after exposure was calculated from the area under the curve.RESULTSl-arginine,d-arginine, and 2.0% saline induced a mean (95% CI) maximal bronchoconstriction of 11.9% (–1.7 to 25.4), 10.0% (2.8 to 17.2), and 8.5% (–2.5 to 19.5) of the starting forced expiratory volume in one second (FEV1), respectively. Exhaled NO declined in proportion to the degree of bronchoconstriction (r=0.60, p<0.01). Bronchoconstriction and the acute reduction in exhaled NO resolved within 15 minutes. The mean post-exposure concentration of NO was 15.75 parts per billion (ppb) afterl-arginine, 15.16 ppb afterd-arginine, and 12.74 ppb after 2.0% saline. The mean (95% CI) difference betweenl-arginine and placebo was 3.01 (0.32 to 5.7) ppb, betweend-arginine and placebo 2.42 (0.10 to 4.74) ppb, and betweenl- andd-arginine 0.59 (–1.56 to 2.74) ppb.CONCLUSIONSExhaled NO decreased with acute bronchoconstriction and returned to baseline with the resolution of bronchoconstriction. Exhaled NO increased following the administration of bothl-arginine andd-arginine. Since NOS is stereospecific, this finding suggests that the increase in exhaled NO is not entirely mediated through an increase in NOS enzyme activity. We suggest that arginine may react in a non-stereospecific fashion with reactive oxygen species present in asthmatic airways.
Transforming growth factor β2induced pleurodesis is not inhibited by corticosteroids
Authors: Lee Y C G , Devin C J , Teixeira L R , Rogers J T , Thompson P J , Lane K B , Light R W 
Published: July 2021

BACKGROUNDTalc and tetracyclines induce pleurodesis by directly injuring the pleura. The injury results in intense inflammation which subsequently leads to fibrosis. Corticosteroids can inhibit talc pleurodesis by reducing the inflammatory process. We hypothesised that transforming growth factor β2(TGFβ2), a fibrogenic cytokine with immunomodulatory functions, could induce effective pleurodesis without generating significant pleural inflammation and therefore remain effective despite co-administration of corticosteroids.METHODSThirty rabbits were divided into two groups. Rabbits in the steroid group received weekly intramuscular injections of triamcinolone diacetate (0.8 mg/kg). Ten rabbits in each group were given 5.0 μg TGFβ2intrapleurally via a chest tube while the remaining five received 1.7 μg TGFβ2. Pleurodesis was graded macroscopically after 14 days from 1 (none) to 8 (>50% symphysis).RESULTSTGFβ2produced excellent pleurodesis at both 5.0 μg and 1.7 μg doses. The pleural effusions produced after the injection were low in all inflammatory markers. No significant differences were seen between the steroid group and controls in macroscopic pleurodesis scores (7.2 (1.3)v7.1 (1.2)), levels of inflammatory markers in the pleural fluids (leucocyte 1107 (387)/mm3v1376 (581)/mm3; protein 3.1 (0.3) mg/dlv2.9 (0.3) mg/dl, and LDH 478 (232) IU/lv502 (123) IU/l), and the degree of microscopic pleural fibrosis and pleural inflammation.CONCLUSIONSTGFβ2can induce effective pleurodesis and remains effective in the presence of high dose parenteral corticosteroids.
Non-invasive ventilation in acute exacerbations of chronic obstructive pulmonary disease: long term survival and predictors of in-hospital outcome
Authors: Plant P K , Owen J L , Elliott M W 
Published: July 2021

BACKGROUNDNon-invasive ventilation (NIV) reduces the need for intubation and the mortality associated with an exacerbation of chronic obstructive pulmonary disease (COPD). This study aimed to identify factors that could be used to stratify patients according to their risk of requiring invasive mechanical ventilation. The second aim was to determine the long term survival of patients treated with and without NIV.METHODSIn this prospective multicentre randomised controlled trial 118 patients were allocated to standard treatment and 118 to NIV between November 1996 and September 1998. Arterial blood gas tensions and respiratory rate were recorded at enrolment and after 1 and 4 hours. Prognostic factors were identified using logistic regression analysis. All patients were followed until death or 1 January 1999.RESULTSAt enrolment the H+ concentration (OR 1.22 per nmol/l, 95% CI 1.09 to 1.37, p<0.01) and Paco2 (OR 1.14 per kPa, 95% CI 1.14 to 1.81, p<0.01) were associated with treatment failure. Allocation to NIV was protective (OR 0.39, 95% CI 0.19 to 0.80). After 4 hours of treatment improvement in acidosis (OR 0.89 per nmol/l, 95% CI 0.82 to 0.97, p<0.01) and fall in respiratory rate (OR 0.92 per breaths/min, 95% CI 0.84 to 0.99, p=0.04) were associated with success. Median length of survival was 16.8 months in those treated with NIV and 13.4 months in those receiving standard treatment (p=0.12). The trend in improved survival was attributable to prevention of death during the index admission.CONCLUSIONInitial pH and hypercapnia can be used to stratify groups of patients according to their risk of needing intubation. NIV reduces this risk and progress should be monitored using change in respiratory rate and pH. The long term survival after NIV is sufficiently good to render treatment appropriate.
Integer dynamics
Authors: Lorenzini Dino , Melistas Mentzelos , Suresh Arvind , Suwama Makoto , Wang Haiyang 
Published: July 2021

Let [Formula: see text] be an integer, and write the base [Formula: see text] expansion of any non-negative integer [Formula: see text] as [Formula: see text], with [Formula: see text] and [Formula: see text] for [Formula: see text]. Let [Formula: see text] denote an integer polynomial such that [Formula: see text] for all [Formula: see text]. Consider the map [Formula: see text], with [Formula: see text]. It is known that the orbit set [Formula: see text] is finite for all [Formula: see text]. Each orbit contains a finite cycle, and for a given [Formula: see text], the union of such cycles over all orbit sets is finite. Fix now an integer [Formula: see text] and let [Formula: see text]. We show that the set of bases [Formula: see text] which have at least one cycle of length [Formula: see text] always contains an arithmetic progression and thus has positive lower density. We also show that a 1978 conjecture of Hasse and Prichett on the set of bases with exactly two cycles needs to be modified, raising the possibility that this set might not be finite.
The palaeoenvironmental context of Toarcian vertebrate-yielding shales of southern France (Hérault)
Authors: Bomou Brahimsamba , Suan Guillaume , Schlögl Jan , Grosjean Anne-Sabine , Suchéras-Marx Baptiste , Adatte Thierry , Spangenberg Jorge E. , Fouché Stéphane , Zacaï Axelle , Gibert Corentin , Brazier Jean-Michel , Perrier Vincent , Vincent Peggy , Janneau Kévin , Martin Jeremy E. 
Published: July 2021

Abstract
The Early Jurassic was marked by several episodes of rapid climate change and environmental perturbation. These changes culminated during the Toarcian Oceanic Anoxic Event (T-OAE), an episode of global warming that led to the widespread deposition of organic-rich shales. The Toarcian shales of NW Europe have also yielded exceptionally preserved fossils of marine vertebrates and invertebrates, but the potential links between the occurrences of these exceptionally preserved fossils and the T-OAE remain poorly investigated. Palaeontological excavations realized in Toarcian strata near Lodève (Hérault, southern France) have yielded several specimens of marine vertebrates and abundant invertebrate fauna. We have developed a multiproxy approach (ammonite biostratigraphy, X-ray diffraction-bulk mineralogy, Rock-Eval pyrolysis, stable isotopes, trace element, phosphorus and mercury contents) to place these findings in a well-defined temporal and palaeoenvironmental context, and hence constrain the factors that led to their remarkable preservation. The Jenkyns Event interval, unambiguously identified at the base of the Toarcian organic-rich shales by a 5‰ negative carbon isotope excursion, records higher mercury fluxes, which suggest a causal link with intense volcanic activity of the Karoo–Ferrar large igneous province. This interval is very condensed and unfossiliferous, and might have been deposited under abnormally low-salinity conditions. Our data show that the deposition of the vertebrate-yielding horizons post-dated the T-OAE by several hundreds of ka, and took place during a prolonged period of widespread oxygen-deficiency and elevated carbon burial. Our results indicate that the unusual richness in vertebrates of the studied site can be explained by a combination of regional factors such as warming-induced, prolonged seafloor anoxia, and more local factors, such as extreme condensation owing to reduced dilution by carbonate and detrital input.
Low-precision Logarithmic Number Systems
Authors: Alam Syed Asad , Garland James , Gregg David 
Published: July 2021

Logarithmic number systems (LNS) are used to represent real numbers in many applications using a constant base raised to a fixed-point exponent making its distribution exponential. This greatly simplifies hardware multiply, divide, and square root. LNS with base-2 is most common, but in this article, we show that for low-precision LNS the choice of base has a significant impact.
We make four main contributions. First, LNS is not closed under addition and subtraction, so the result is approximate. We show that choosing a suitable base can manipulate the distribution to reduce the average error. Second, we show that low-precision LNS addition and subtraction can be implemented efficiently in logic rather than commonly used ROM lookup tables, the complexity of which can be reduced by an appropriate choice of base. A similar effect is shown where the result of arithmetic has greater precision than the input. Third, where input data from external sources is not expected to be in LNS, we can reduce the conversion error by selecting a LNS base to match the expected distribution of the input. Thus, there is no one base that gives the global optimum, and base selection is a trade-off between different factors. Fourth, we show that circuits realized in LNS require lower area and power consumption for short word lengths.
CIB-HIER
Authors: Li Cunlu , Dong Dezun , Yang Shazhou , Liao Xiangke , Sun Guangyu , Liu Yongheng 
Published: July 2021

Hierarchical organization is widely used in high-radix routers to enable efficient scaling to higher switch port count. A general-purpose hierarchical router must be symmetrically designed with the same input buffer depth, resulting in a large amount of unused input buffers due to the different link lengths. Sharing input buffers between different input ports can improve buffer utilization, but the implementation overhead also increases with the number of shared ports. Previous work allowed input buffers to be shared among all router ports, which maximizes the buffer utilization but also introduces higher implementation complexity. Moreover, such design can impair performance when faced with long packets, due to the head-of-line blocking in intermediate buffers.
In this work, we explain that sharing unused buffers between a subset of router ports is a more efficient design. Based on this observation, we propose Centralized Input Buffer Design in Hierarchical High-radix Routers (CIB-HIER), a novel centralized input buffer design for hierarchical high-radix routers. CIB-HIER integrates multiple input ports onto a single tile and organizes all unused input buffers in the tile as a centralized input buffer. CIB-HIER only allows the centralized input buffer to be shared between ports on the same tile, without introducing additional intermediate virtual channels or global scheduling circuits. Going beyond the basic design of CIB-HIER, the centralized input buffer can be used to relieve the head-of-line blocking caused by shallow intermediate buffers, by stashing long packets in the centralized input buffer. Experimental results show that CIB-HIER is highly effective and can significantly increase the throughput of high-radix routers.