Publications by authors named "Richard Allan"

Purpose: Report 2-year outcomes from a prospective, multicenter, non-randomized, single-arm study designed to further assess the safety and effectiveness of the Celect and the Günther Tulip Vena Cava Filters.

Materials And Methods: The BLIND study enrolled patients requiring temporary or permanent IVC filter placement for the prevention of pulmonary embolism (PE). The primary effectiveness endpoint was the rate of technical placement success and 12-month freedom from new symptomatic PE while a filter was indwelling.

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Unlabelled: As observed by the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow On (GRACE-FO) missions, global terrestrial water storage (TWS), excluding ice sheets and glaciers, declined rapidly between May 2014 and March 2016. By 2023, it had not yet recovered, with the upper end of its range remaining 1 cm equivalent height of water below the upper end of the earlier range. Beginning with a record-setting drought in northeastern South America, a series of droughts on five continents helped to prevent global TWS from rebounding.

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Satellite observations from the Clouds and the Earth's Radiant Energy System show that Earth's energy imbalance has doubled from 0.5 ± 0.2 Wm during the first 10 years of this century to 1.

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Background: Ongoing conflict between multiple armed groups, including pastoralist herders in the Central African Republic (CAR) causes frequent population displacements, food insecurity and scarcity of healthcare services. The inaccessibility and insecurity of many areas of CAR limit data collection and assessments from national nutritional surveys. Community health workers (CHWs) trained by an international non-governmental organisation, The MENTOR Initiative, deliver basic healthcare to children under 5 years old living in hard-to-reach and conflict-affected areas in eight subprefectures of north-west CAR.

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Large-scale afforestation programmes are generally presented as effective ways of increasing the terrestrial carbon sink while preserving water availability and biodiversity. Yet, a meta-analysis of both numerical and observational studies suggests that further research is needed to support this view. The use of inappropriate concepts (e.

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Future projections of precipitation are uncertain, hampering effective climate adaptation strategies globally. Our understanding of changes across multiple climate model simulations under a warmer climate is limited by this lack of coherence across models. Here, we address this challenge introducing an approach that detects agreement in drier and wetter conditions by evaluating continuous 120-year time-series with trends, across 146 Global Climate Model (GCM) runs and two elevated greenhouse gas (GHG) emissions scenarios.

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Mushroom (amatoxin) poisoning from ingestion is a rare but life-threatening medical emergency characterized by gastrointestinal symptoms before progression to multisystem organ failure in severe cases. Many therapies of amatoxin intoxication have been described, including supportive care, medical therapies, detoxification strategies, and liver transplant. The evidence supporting these therapies remains limited due to the rarity of amatoxin poisoning and challenge of a timely diagnosis.

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Purpose: To compare the clinical outcomes of common femoral artery (CFA) atherosclerotic disease treated with either surgical endarterectomy or an interwoven nitinol wire stent system.

Materials And Methods: A retrospective review was conducted of all patients with chronic, de novo atherosclerotic CFA disease treated with surgical endarterectomy (CFAE) or stent placement between July 2019 and March 2022. Outcome measures assessed up to 12 months after procedure included clinical improvement, primary restenosis, target vessel revascularization (TVR), major adverse limb events (MALEs), and all-cause mortality.

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Background: Malaria control in Liberia depends upon universal coverage with pyrethroid-impregnated long-lasting insecticidal nets (LLINs). Despite regular mass distribution, LLIN coverage and usage is patchy. Pyrethroid resistance in malaria vectors may further reduce LLIN efficacy.

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Background: Declines in global malaria cases and deaths since the millennium are currently challenged by multiple factors including funding limitations, limits of, and resistance to vector control tools, and also recent spread of the invasive vector species, Anopheles stephensi-especially into novel urban settings where malaria rates are typically low. Coupled with general increases in urbanization and escalations in the number of conflicts creating rapid and unplanned population displacement into temporary shelter camps within host urban areas, particularly in the Middle East and sub-Saharan Africa, increased urban malaria is a major threat to control and elimination.

Methods: Entomological monitoring surveys (targeting Aedes aegypti) of water containers across urban areas hosting internally displaced people (IDP) communities in Aden city, Yemen, were performed by The MENTOR Initiative, a non-governmental organisation.

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Background: Peripheral artery calcium scoring systems are commonly used in clinical trials to categorize calcium severity but there are little data on their accuracy and reliability. The purpose of this study was to investigate the accuracy and reliability of these systems.

Methods: Angiographic, computed tomography angiography, and intravascular ultrasound (IVUS) imaging were obtained from 47 consecutive cases sourced from a prospectively collected database of patients undergoing femoropopliteal artery endovascular intervention.

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Aedes mosquitoes are responsible for transmission of dengue, chikungunya, Zika, and yellow fever viruses. Aedes mosquitoes are the pathfinders of invasive urban-living mosquitoes, and have spread into 129 countries over the past five decades. In the past 10 years Anopheles stephensi has been identified within densely populated cities in Yemen and across the Horn of Africa and as far west as Nigeria.

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Until now, driving mechanisms behind recurring droughts and hydroclimate variations that controls the Nile River Basin (NRB) remains poorly understood. Our results show significant hydroclimatic changes that contributed to recent increasing aridity of NRB since the 1970s. Besides climate warming, the influence of stronger ENSO and Indian Ocean dipole (IOD) in NRB has increased after 1980s, which have significantly contributed to NRB's drought severity at inter-annual to inter-decadal timescales.

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Background: Acute acalculous cholecystitis (AAC) is often diagnosed in critically ill patients. Percutaneous cholecystostomy tube (PCT) placement facilitates less invasive gallbladder decompression in patients who are poor surgical candidates. Specific guidelines for optimal management of AAC patients following PCT placement remain to be defined.

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Objectives: The aim of this study was to investigate whether the addition of intravascular ultrasound (IVUS) guidance during femoropopliteal artery interventions reduced the rate of binary restenosis within 12 months compared with angiographic guidance alone.

Background: IVUS is more accurate than angiography for assessment of vessel size and disease severity. Low-level studies suggest that the use of IVUS in femoropopliteal endovascular interventions improves outcomes, but currently, no level 1 evidence exists.

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Background: Percutaneous cholecystostomy tubes (PCT) are utilized in the management of acute cholecystitis in patients deemed unsuitable for surgery. However, the drive for these decisions and the outcomes remain understudied. We sought to characterize the practices and utilization of PCT and evaluate associated outcomes at an urban medical center.

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Purpose: Objective assessment of dissection severity is difficult. Recognition of this has led to the creation of classification systems. This study investigated the performance of the National Heart Lung and Blood Institute (NHLBI) and Kobayashi systems at differentiating severity of femoropopliteal dissection using intravascular ultrasound (IVUS) as the reference standard.

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Both asthma and chronic obstructive pulmonary disease (COPD) are inflammatory chronic respiratory conditions with high rates of morbidity and mortality worldwide. The objectives of this review are to briefly describe the pathophysiology and epidemiology of asthma and COPD, discuss guideline recommendations for uncontrolled disease, and review a new generic option for the treatment of asthma and COPD. Although mild forms of these diseases may be controlled with as-needed pharmacotherapy, uncontrolled or persistent asthma and moderate or severe COPD uncontrolled by bronchodilators with elevated eosinophilia or frequent exacerbations may require intervention with combination therapy with inhaled corticosteroids (ICS) and long-acting beta agonists (LABAs), according to international guidelines.

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Lung cancer is the leading cause of cancer death worldwide, with poor prognosis and a high rate of recurrence despite early surgical removal. Hypoxic regions within tumors represent sources of aggressiveness and resistance to therapy. Although long non-coding RNAs (lncRNAs) are increasingly recognized as major gene expression regulators, their regulation and function following hypoxic stress are still largely unexplored.

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A large number of recent studies have aimed at understanding short-duration rainfall extremes, due to their impacts on flash floods, landslides and debris flows and potential for these to worsen with global warming. This has been led in a concerted international effort by the INTENSE Crosscutting Project of the GEWEX (Global Energy and Water Exchanges) Hydroclimatology Panel. Here, we summarize the main findings so far and suggest future directions for research, including: the benefits of convection-permitting climate modelling; towards understanding mechanisms of change; the usefulness of temperature-scaling relations; towards detecting and attributing extreme rainfall change; and the need for international coordination and collaboration.

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Introduction: Hip and groin related pain is a common complaint among the military population across UK Defence Rehabilitation and addressing associated biomechanical dysfunction is a key treatment goal. Personnel are exposed to complex occupational loads, therefore assessing movement during demanding tasks may expose biomechanical deficits. Observing biomechanical and clinical outcomes in response to treatment is therefore an important consideration.

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Background: Vascular micro-channels within chronic total occlusions (CTO) have been identified in histopathology and animal studies. They have been proposed as a potential path for achieving endovascular crossing via the lumen. There are currently no noninvasive means of imaging these structures.

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