672 research outputs found
Optically stimulated luminescence profiling and dating of earthworks: the creation and development of prehistoric field boundaries at Bosigran, Cornwall
Accurately dating the creation and development of earthwork features is a long-standing problem for archaeologists. This paper presents results from Bosigran (Cornwall, UK), where boundary banks believed to be prehistoric in origin were assessed using optically-stimulated luminescence profiling and dating (OSL-PD). The results provide secure construction dates for different boundaries in the Bronze Age and Iron Age, as well as chronologies for their early medieval and later development. The paper demonstrates not only the prehistoric origins of these distinctive west Cornish field systems, but also a practical and cost-effective methodology which is suitable for dating earthworks across the world
Cancer event rate and mortality with thienopyridines: a systematic review and meta-analysis
Introduction
Thienopyridines are a class of antiplatelet drugs widely used in cardiovascular disease prevention and treatment. A recent concern has come to light regarding the safety of thienopyridines because of the possible risk of malignancy. We therefore performed a systematic review and meta-analysis to evaluate the association between thienopyridine exposure and malignancy.
Methods
We searched the MEDLINE and EMBASE databases in March 2016 for studies that evaluated incident cancer and cancer mortality with and without exposure to thienopyridines. Relevant studies were identified, and data were extracted and analysed using random-effects meta-analysis.
Results
A total of nine studies (six randomised controlled trials and three cohort studies) that included 282,084 participants were included. The cancer event rate with clopidogrel and prasugrel was 3.25% and 1.58% respectively. When compared with standard aspirin or placebo, thienopyridines are not significantly associated with cancer mortality and event rate (odds ratio [OR] 1.12, 95% confidence interval [CI] 0.80–1.56, n = 3; and OR 0.92, 95% CI 0.52–1.64, n = 2, respectively. Further analyses examining clopidogrel showed no significant association with cancer event rate or malignancy-related death. When comparing prasugrel with clopidogrel, no significant association was noted for cancer event rate (OR 1.10, 95% CI 0.89–1.37, n = 2]. Subanalyses according to cancer location showed that thienopyridines are not significantly associated with malignancy mortality and/or incidence.
Conclusions
Our results suggest that there is currently insufficient evidence to suggest that thienopyridine exposure is associated with an increased risk of cancer event rate or mortality
The potential of portable luminescence readers in geomorphological investigations : a review
The development of functional portable optically stimulated luminescence (OSL) readers over the last decade has provided practitioners with the capability to acquire luminescence signals from geological materials relatively rapidly, which allows for expedient preliminary chronostratigraphic insight when working with complex depositional systems of late Quaternary age. Typically, when using the portable OSL reader, infrared (IR) or blue post-IR OSL signals are acquired from bulk unprocessed materials, in contrast to regular luminescence dating which is usually based on measurements on pure quartz or feldspar mineral separates, or on select silt-sized polymineralic portions. To demonstrate the utility of portable OSL measurements, this paper outlines the basic features of portable OSL readers and their constraints. Afterwards, case studies in which the instrument has been used to elucidate cryptostratigraphic variations in sedimentary sequences for geomorphological applications are reviewed. The studies can generally be grouped into three main categories. The first includes studies where the variation of portable OSL reader luminescence signal intensities with depth are plotted to generate profiles that contextualise sediment stratigraphy. In the second group, portable OSL reader luminescence signal intensities are used to interpret sediment processes that shed light on depositional histories. In the last category, luminescence signals from the portable OSL reader are calibrated to approximate numerical burial ages of depositional units. The paper concludes with a discussion of possible future directions.PostprintPeer reviewe
Methods to Quantify Pharmacologically Induced Alterations in Motor Function in Human Incomplete SCI
Spinal cord injury (SCI) is a debilitating disorder, which produces profound deficits in volitional motor control. Following medical stabilization, recovery from SCI typically involves long term rehabilitation. While recovery of walking ability is a primary goal in many patients early after injury, those with a motor incomplete SCI, indicating partial preservation of volitional control, may have the sufficient residual descending pathways necessary to attain this goal. However, despite physical interventions, motor impairments including weakness, and the manifestation of abnormal involuntary reflex activity, called spasticity or spasms, are thought to contribute to reduced walking recovery. Doctrinaire thought suggests that remediation of this abnormal motor reflexes associated with SCI will produce functional benefits to the patient. For example, physicians and therapists will provide specific pharmacological or physical interventions directed towards reducing spasticity or spasms, although there continues to be little empirical data suggesting that these strategies improve walking ability
Serosurvey of Coxiella burnetii (Q fever) in Dromedary Camels (Camelus dromedarius) in Laikipia County, Kenya
Dromedary camels (Camelus dromedarius) are an important protein source for people in semi-arid and arid regions of Africa. In Kenya, camel populations have grown dramatically in the past few decades resulting in the potential for increased disease transmission between humans and camels. An estimated four million Kenyans drink unpasteurized camel milk, which poses a disease risk. We evaluated the seroprevalence of a significant zoonotic pathogen, Coxiella burnetii (Q fever), among 334 camels from nine herds in Laikipia County, Kenya. Serum testing revealed 18.6% positive seroprevalence of Coxiella burnetii (n = 344). Increasing camel age was positively associated with C. burnetii seroprevalence (OR = 5.36). Our study confirmed that camels living in Laikipia County, Kenya, have been exposed to the zoonotic pathogen, C. burnetii. Further research to evaluate the role of camels in disease transmission to other livestock, wildlife and humans in Kenya should be conducted
Agricultural terraces in the Mediterranean: a multidisciplinary approach to understanding human-landscape interactions
Intracoronary imaging in PCI for acute coronary syndrome: Insights from British Cardiovascular Intervention Society registry
Background: While previous studies have demonstrated the superiority of ICI-guided PCI over an angiography-based approach, there are limited data on all-comer ACS patients. This study aimed to identify the characteristics and in-hospital outcomes of patients undergoing intracoronary imaging (ICI) guided percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Methods: All patient undergoing PCI for ACS in England and Wales between 2006 and 2019 were retrospectively analyzed and stratified according to ICI utilization. The outcomes assessed were in-hospital all-cause mortality and major adverse cardiovascular and cerebrovascular events (MACCE) using multivariable logistic regression models. Results: 598,921 patients underwent PCI for ACS, of which 41,716 (7.0 %) had ICI which was predominantly driven by IVUS use (5.6 %). ICI use steadily increased from 1.4 % in 2006 to 13.5 % in 2019. Adjusted odds of mortality (OR 0.69, 95%CI 0.58–0.83) and MACCE (OR 0.77, 95%CI 0.73–0.83) were significantly lower in the ICI group. The association between ICI and improved outcomes varied according to vessel treated with both left main stem (LMS) and LMS/left anterior descending (LAD) PCI associated with significantly lower odds of mortality (OR 0.34, 95%CI 0.27–0.44, OR 0.51 95%CI 0.45–0.56) and MACCE (OR 0.44 95%CI 0.35–0.54, OR 0.67 95%CI 0.62–0.72) respectively. Conclusions: Although ICI use has steadily increased, less than one in seven patients underwent ICI-guided PCI. The association between ICI use and improved in-hospital outcomes was mainly observed in PCI procedures involving LMS and LAD
Impact of intracoronary imaging-guided percutaneous coronary intervention on procedural outcomes among complex patient groups
Background Intracoronary imaging (ICI) has been previously shown to improve survival and clinical outcomes after percutaneous coronary intervention (PCI). However, whether this prognostic benefit is sustained across different indications/patient groups remains unclear. Methods All PCI procedures performed in England and Wales between 1st April 2014 and 31st March 2020 were retrospectively analysed. The association between ICI use and in-hospital MACCE (major adverse cardiovascular and cerebrovascular outcomes; composite of all-cause mortality, stroke and reinfarction) and mortality was examined using multivariable logistic regression analysis for each imaging-recommended indication (stent thrombosis (ST), in-stent restenosis, stent length>60mm, acute coronary syndrome (ACS) indications, chronic total occlusion, left main stem (LMS) intervention, renal failure and bioresorbable vascular scaffolds (BVS)). Results Of 555,398 PCI procedures, 10.8% (n=59,752) were performed under ICI guidance. ICI use doubled between 2014 (7.8%) and 2020 (17.5%). ICI use was highest for BVS (44.7%) and LMS PCI (41.2%) cases and lowest in ACS (9%). Overall, the odds ratios (OR) of in-hospital MACCE and mortality were only reduced with ICI-guided PCI in cases with an imaging-recommended indication (OR 0.75 95% confidence interval (CI) 0.69-0.81 and OR 0.69 95%CI 0.63-0.76, respectively). Only specific imaging-recommended indications were associated with reduced MACCE and mortality, including LMS PCI (OR 0.45 95%CI 0.39-0.52 and 0.41 95%CI 0.35-0.48, respectively), ACS (OR 0.76 95%CI 0.70-0.82 and 0.70 95%CI 0.63-0.77), stent length>60mm (OR 0.75 95%CI 0.59-0.94 and 0.72 95%CI 0.54-0.95). ST was only associated with lower mortality (OR: 0.69 95%CI 0.52-0.91) while renal failure was associated with reduced MACCE (OR 0.77 95%CI 0.60-0.99) but not mortality. (Figure 1) Conclusion The utilisation of ICI has more than doubled over a seven-year period at a national level but remains low, with less than 1-in-5 procedures performed under ICI guidance. In-hospital survival was better with ICI-guided than angiography-guided PCI, albeit only for specific indications.Figure
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