1,901 research outputs found
Cardiovascular outcomes of type 2 diabetic patients treated with DPP‑4 inhibitors versus sulphonylureas as add-on to metformin in clinical practice
DPP-4 inhibitors (DPP-4i) and sulphonylureas remain the most widely prescribed add-on treatments after metformin. However, there is limited evidence from clinical practice comparing major adverse cardiovascular events (MACE) in patients prescribed these treatments, particularly among those without prior history of MACE and from vulnerable population groups. Using electronic health records from UK primary care, we undertook a retrospective cohort study with people diagnosed type-2 diabetes mellitus, comparing incidence of MACE (myocardial infarction, stroke, major cardiovascular surgery, unstable angina) and all-cause mortality among those prescribed DPP-4i versus sulphonylureas as add-on to metformin. We stratified analysis by history of MACE, age, social deprivation and comorbidities and adjusted for HbA1c, weight, smoking-status, comorbidities and medications. We identified 17,570 patients prescribed sulphonylureas and 6,267 prescribed DPP-4i between 2008–2017. Of these, 16.3% had pre-existing MACE. Primary incidence of MACE was similar in patients prescribed DPP-4i and sulphonylureas (10.3 vs 8.5 events per 1000 person-years; adjusted Hazard Ratio (adjHR): 0.94; 95%CI 0.80–1.14). For those with pre-existing MACE, rates for recurrence were higher overall, but similar between the two groups (21.8 vs 17.2 events per 1000 person-years; adjHR: 0.93; 95%CI 0.69–1.24). For those aged over 75 and with BMI less than 25 kg/m2 there was a protective effect for DPP-I, warranting further investigation. Patients initiating a DPP-4i had similar risk of cardiovascular outcomes to those initiating a sulphonylurea. This indicates the choice should be based on safety and cost, not cardiovascular prognosis, when deciding between a DPP-4i or sulphonylurea as add-on to metformin
Ultrathin 2 nm gold as ideal impedance-matched absorber for infrared light
Thermal detectors are a cornerstone of infrared (IR) and terahertz (THz)
technology due to their broad spectral range. These detectors call for suitable
broad spectral absorbers with minimalthermal mass. Often this is realized by
plasmonic absorbers, which ensure a high absorptivity butonly for a narrow
spectral band. Alternativly, a common approach is based on impedance-matching
the sheet resistance of a thin metallic film to half the free-space impedance.
Thereby, it is possible to achieve a wavelength-independent absorptivity of up
to 50 %, depending on the dielectric properties of the underlying substrate.
However, existing absorber films typicallyrequire a thickness of the order of
tens of nanometers, such as titanium nitride (14 nm), whichcan significantly
deteriorate the response of a thermal transducers. Here, we present the
application of ultrathin gold (2 nm) on top of a 1.2 nm copper oxide seed layer
as an effective IR absorber. An almost wavelength-independent and long-time
stable absorptivity of 47(3) %, ranging from 2 m to 20 m, could be
obtained and is further discussed. The presented gold thin-film represents
analmost ideal impedance-matched IR absorber that allows a significant
improvement of state-of-the-art thermal detector technology
Enhancing Symbolic Execution of Heap-based Programs with Separation Logic for Test Input Generation
Symbolic execution is a well established method for test input generation.
Despite of having achieved tremendous success over numerical domains, existing
symbolic execution techniques for heap-based programs are limited due to the
lack of a succinct and precise description for symbolic values over unbounded
heaps. In this work, we present a new symbolic execution method for heap-based
programs based on separation logic. The essence of our proposal is
context-sensitive lazy initialization, a novel approach for efficient test
input generation. Our approach differs from existing approaches in two ways.
Firstly, our approach is based on separation logic, which allows us to
precisely capture preconditions of heap-based programs so that we avoid
generating invalid test inputs. Secondly, we generate only fully initialized
test inputs, which are more useful in practice compared to those partially
initialized test inputs generated by the state-of-the-art tools. We have
implemented our approach as a tool, called Java StarFinder, and evaluated it on
a set of programs with complex heap inputs. The results show that our approach
significantly reduces the number of invalid test inputs and improves the test
coverage
Proteomic and Functional Studies Reveal Detyrosinated Tubulin as Treatment Target in Sarcomere Mutation-Induced Hypertrophic Cardiomyopathy
BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease. While ≈50% of patients with HCM carry a sarcomere gene mutation (sarcomere mutation-positive, HCMSMP), the genetic background is unknown in the other half of the patients (sarcomere mutation-negative, HCMSMN). Genotype-specific differences have been reported in cardiac function. Moreover, HCMSMN patients have later disease onset and a better prognosis than HCMSMP patients. To define if genotype-specific derailments at the protein level may explain the heterogeneity in disease development, we performed a proteomic analysis in cardiac tissue from a clinically well-phenotyped HCM patient group. METHODS: A proteomics screen was performed in cardiac tissue from 39 HCMSMP patients, 11HCMSMN patients, and 8 nonfailing controls. Patients with HCM had obstructive cardiomyopathy with left ventricular outflow tract obstruction and diastolic dysfunction. A novel MYBPC32373insG mouse model was used to confirm functional relevance of our proteomic findings. RESULTS: In all HCM patient samples, we found lower levels of metabolic pathway proteins and higher levels of extracellular matrix proteins. Levels of total and detyrosinated α-tubulin were markedly higher in HCMSMP than in HCMSMN and controls. Higher tubulin detyrosination was also found in 2 unrelated MYBPC3 mouse models and its inhibition with parthenolide normalized contraction and relaxation time of isolated cardiomyocytes. CONCLUSIONS: Our findings indicate that microtubules and especially its detyrosination contribute to the pathomechanism of patients with HCMSMP. This is of clinical importance since it represents a potential treatment target to improve cardiac function in patients with HCMSMP, whereas a beneficial effect may be limited in patients with HCMSMN
Quantitative imaging of concentrated suspensions under flow
We review recent advances in imaging the flow of concentrated suspensions,
focussing on the use of confocal microscopy to obtain time-resolved information
on the single-particle level in these systems. After motivating the need for
quantitative (confocal) imaging in suspension rheology, we briefly describe the
particles, sample environments, microscopy tools and analysis algorithms needed
to perform this kind of experiments. The second part of the review focusses on
microscopic aspects of the flow of concentrated model hard-sphere-like
suspensions, and the relation to non-linear rheological phenomena such as
yielding, shear localization, wall slip and shear-induced ordering. Both
Brownian and non-Brownian systems will be described. We show how quantitative
imaging can improve our understanding of the connection between microscopic
dynamics and bulk flow.Comment: Review on imaging hard-sphere suspensions, incl summary of
methodology. Submitted for special volume 'High Solid Dispersions' ed. M.
Cloitre, Vol. xx of 'Advances and Polymer Science' (Springer, Berlin, 2009);
22 pages, 16 fig
Drones count wildlife more accurately and precisely than humans
Human activities are creating environmental conditions that pose threats and present opportunities for wildlife. In turn, this creates challenges for conservation managers. Some species have benefited from anthropogenic actions. For example, many invasive species profit from human‐assisted dispersal (Banks, Paini, Bayliss, & Hodda, 2015; Hulme, 2009), and mesopredators may thrive following human‐driven loss of top predators (Ritchie & Johnson, 2009). However, in many cases, wildlife populations are undergoing alarming declines, and extinction rates are now as high as 100‐fold greater than the background extinction rate (Ceballos et al., 2015). Ecological monitoring is essential for understanding these population dynamics, and rigorous monitoring facilitates informed management. The effectiveness of management decision‐making is often dependent on the accuracy and timeliness of the relevant ecological data upon which decisions are based, meaning that improvements to data collection methods may herald improved ecological outcomes from management actions
Outcome of experimental stroke in C57Bl/6 and Sv/129 mice assessed by multimodal ultra-high field MRI
Transgenic mice bred on C57Bl/6 or Sv/129 genetic background are frequently used in stroke research. It is well established that variations in cerebrovascular anatomy and hemodynamics can influence stroke outcome in different inbred mouse lines. We compared stroke development in C57Bl/6 and Sv/129 mice in the widely used model of transient middle cerebral artery occlusion (tMCAO) by multimodal ultra-high field magnetic resonance imaging (MRI)
Interactive metagenomic visualization in a Web browser
<p>Abstract</p> <p>Background</p> <p>A critical output of metagenomic studies is the estimation of abundances of taxonomical or functional groups. The inherent uncertainty in assignments to these groups makes it important to consider both their hierarchical contexts and their prediction confidence. The current tools for visualizing metagenomic data, however, omit or distort quantitative hierarchical relationships and lack the facility for displaying secondary variables.</p> <p>Results</p> <p>Here we present Krona, a new visualization tool that allows intuitive exploration of relative abundances and confidences within the complex hierarchies of metagenomic classifications. Krona combines a variant of radial, space-filling displays with parametric coloring and interactive polar-coordinate zooming. The HTML5 and JavaScript implementation enables fully interactive charts that can be explored with any modern Web browser, without the need for installed software or plug-ins. This Web-based architecture also allows each chart to be an independent document, making them easy to share via e-mail or post to a standard Web server. To illustrate Krona's utility, we describe its application to various metagenomic data sets and its compatibility with popular metagenomic analysis tools.</p> <p>Conclusions</p> <p>Krona is both a powerful metagenomic visualization tool and a demonstration of the potential of HTML5 for highly accessible bioinformatic visualizations. Its rich and interactive displays facilitate more informed interpretations of metagenomic analyses, while its implementation as a browser-based application makes it extremely portable and easily adopted into existing analysis packages. Both the Krona rendering code and conversion tools are freely available under a BSD open-source license, and available from: <url>http://krona.sourceforge.net</url>.</p
Robust Automated Tumour Segmentation on Histological and Immunohistochemical Tissue Images
Tissue microarray (TMA) is a high throughput analysis tool to identify new diagnostic and prognostic markers in human cancers. However, standard automated method in tumour detection on both routine histochemical and immunohistochemistry (IHC) images is under developed. This paper presents a robust automated tumour cell segmentation model which can be applied to both routine histochemical tissue slides and IHC slides and deal with finer pixel-based segmentation in comparison with blob or area based segmentation by existing approaches. The presented technique greatly improves the process of TMA construction and plays an important role in automated IHC quantification in biomarker analysis where excluding stroma areas is critical. With the finest pixel-based evaluation (instead of area-based or object-based), the experimental results show that the proposed method is able to achieve 80% accuracy and 78% accuracy in two different types of pathological virtual slides, i.e., routine histochemical H&E and IHC images, respectively. The presented technique greatly reduces labor-intensive workloads for pathologists and highly speeds up the process of TMA construction and provides a possibility for fully automated IHC quantification
Imaging in breast cancer: Diffuse optics in breast cancer: detecting tumors in pre-menopausal women and monitoring neoadjuvant chemotherapy
Diffuse optical spectroscopy (DOS) and diffuse optical imaging (DOI) are non-invasive diagnostic techniques that employ near-infrared (NIR) light to quantitatively characterize the optical properties of centimeter-thick, multiple-scattering tissues. Although NIR was first applied to breast diaphanography more than 70 years ago, quantitative optical methods employing time- or frequency-domain 'photon migration' technologies have only recently been used for breast imaging. Because their performance is not limited by mammographic density, optical methods can provide new insight regarding tissue functional changes associated with the appearance, progression, and treatment of breast cancer, particularly for younger women and high-risk subjects who may not benefit from conventional imaging methods. This paper reviews the principles of diffuse optics and describes the development of broadband DOS for quantitatively measuring the optical and physiological properties of thick tissues. Clinical results are shown highlighting the sensitivity of diffuse optics to malignant breast tumors in 12 pre-menopausal subjects ranging in age from 30 to 39 years and a patient undergoing neoadjuvant chemotherapy for locally advanced breast cancer. Significant contrast was observed between normal and tumor regions of tissue for deoxy-hemoglobin (p = 0.005), oxy-hemoglobin (p = 0.002), water (p = 0.014), and lipids (p = 0.0003). Tissue hemoglobin saturation was not found to be a reliable parameter for distinguishing between tumor and normal tissues. Optical data were converted into a tissue optical index that decreased 50% within 1 week in response to neoadjuvant chemotherapy. These results suggest a potential role for diffuse optics as a bedside monitoring tool that could aid the development of new strategies for individualized patient care
- …