8,331 research outputs found
End-to-End Learning of Video Super-Resolution with Motion Compensation
Learning approaches have shown great success in the task of super-resolving
an image given a low resolution input. Video super-resolution aims for
exploiting additionally the information from multiple images. Typically, the
images are related via optical flow and consecutive image warping. In this
paper, we provide an end-to-end video super-resolution network that, in
contrast to previous works, includes the estimation of optical flow in the
overall network architecture. We analyze the usage of optical flow for video
super-resolution and find that common off-the-shelf image warping does not
allow video super-resolution to benefit much from optical flow. We rather
propose an operation for motion compensation that performs warping from low to
high resolution directly. We show that with this network configuration, video
super-resolution can benefit from optical flow and we obtain state-of-the-art
results on the popular test sets. We also show that the processing of whole
images rather than independent patches is responsible for a large increase in
accuracy.Comment: Accepted to GCPR201
Rapid Identification of Pathogenic Variants in Two Cases of Charcot-Marie-Tooth Disease by Gene-Panel Sequencing
published_or_final_versio
The Role of Connexins in Wound Healing and Repair: Novel Therapeutic Approaches
Gap junctions are intercellular proteins responsible for mediating both electrical and biochemical coupling through the exchange of ions, second messengers and small metabolites. They consist of two connexons, with (one) connexon supplied by each cell. A connexon is a hexamer of connexins and currently more than 20 connexin isoforms have been described in the literature thus far. Connexins have a short half-life, and therefore gap junction remodeling constantly occurs with a high turnover rate. Post-translational modification, such as phosphorylation, can modify their channel activities. In this article, the roles of connexins in wound healing and repair are reviewed. Novel strategies for modulating the function or expression of connexins, such as the use of antisense technology, synthetic mimetic peptides and bioactive materials for the treatment of skin wounds, diabetic and pressure ulcers as well as cornea wounds, are considered.GT received a BBSRC Doctoral Training Award at the University of Cambridge and thanks The Croucher Foundation for supporting his clinical assistant professorship. YC is supported by the ESRC for her research at the University of Cambridge
Dual Drug-Loaded Biofunctionalized Amphiphilic Chitosan Nanoparticles: Enhanced Synergy between Cisplatin and Demethoxycurcumin against Multidrug-Resistant Stem-Like Lung Cancer Cells
Lung cancer kills more humans than any other cancer and multidrug resistance (MDR) in cancer stem-like cells (CSC) is emerging as a reason for failed treatments. One concept which addresses this root cause of treatment failure is the utilization of nanoparticles to simultaneously deliver dual drugs to cancer cells with synergistic performance, easy to envision - hard to achieve. It is challenging to simultaneously load drugs of highly different physicochemical properties into one nanoparticle, release kinetics may differ between drugs and general requirements for biomedical nanoparticles apply. Here self-assembled nanoparticles of amphiphilic carboxymethyl-hexanoyl chitosan (CHC) were shown to present nano-microenvironments enabling simultaneous loading of hydrophilic and hydrophobic drugs. This was expanded into a dual-drug nano-delivery system to treat lung CSC. CHC nanoparticles were loaded/chemically modified with the anticancer drug cisplatin and the MDR-suppressing Chinese herbal extract demethoxycurcumin, followed by biofunctionalization with CD133 antibody for enhanced uptake by lung CSC, all in a feasible one-pot preparation. The nanoparticles were characterized with regard to chemistry, size, zeta potential and drug loading/release. Biofunctionalized and non-functionalized nanoparticles were investigated for uptake by lung CSC. Subsequently the cytotoxicity of single and dual drugs, free in solution or in nanoparticles, was evaluated against lung CSC at different doses. From the dose response at different concentrations the degree of synergy was determined through Chou-Talalay's Plot. The biofunctionalized nanoparticles promoted synergistic effects between the drugs and were highly effective against MDR lung CSC. The efficacy and feasible one-pot preparation suggest preclinical studies using relevant disease models to be justified
Uncoupling Protein-2 Mediates DPP-4 Inhibitor-Induced Restoration of Endothelial Function in Hypertension Through Reducing Oxidative Stress
published_or_final_versio
Electronic transport in polycrystalline graphene
Most materials in available macroscopic quantities are polycrystalline.
Graphene, a recently discovered two-dimensional form of carbon with strong
potential for replacing silicon in future electronics, is no exception. There
is growing evidence of the polycrystalline nature of graphene samples obtained
using various techniques. Grain boundaries, intrinsic topological defects of
polycrystalline materials, are expected to dramatically alter the electronic
transport in graphene. Here, we develop a theory of charge carrier transmission
through grain boundaries composed of a periodic array of dislocations in
graphene based on the momentum conservation principle. Depending on the grain
boundary structure we find two distinct transport behaviours - either high
transparency, or perfect reflection of charge carriers over remarkably large
energy ranges. First-principles quantum transport calculations are used to
verify and further investigate this striking behaviour. Our study sheds light
on the transport properties of large-area graphene samples. Furthermore,
purposeful engineering of periodic grain boundaries with tunable transport gaps
would allow for controlling charge currents without the need of introducing
bulk band gaps in otherwise semimetallic graphene. The proposed approach can be
regarded as a means towards building practical graphene electronics.Comment: accepted in Nature Material
Mouse models of atherosclerosis: a historical perspective and recent advances.
Atherosclerosis represents a significant cause of morbidity and mortality in both the developed and developing countries. Animal models of atherosclerosis have served as valuable tools for providing insights on its aetiology, pathophysiology and complications. They can be used for invasive interrogation of physiological function and provide a platform for testing the efficacy and safety of different pharmacological therapies. Compared to studies using human subjects, animal models have the advantages of being easier to manage, with controllable diet and environmental risk factors. Moreover, pathophysiological changes can be induced either genetically or pharmacologically to study the harmful effects of these interventions. There is no single ideal animal model, as different systems are suitable for different research objectives. A good understanding of the similarities and differences to humans enables effective extrapolation of data for translational application. In this article, we will examine the different mouse models for the study and elucidation of the pathophysiological mechanisms underlying atherosclerosis. We also review recent advances in the field, such as the role of oxidative stress in promoting endoplasmic reticulum stress, mitochondrial dysfunction and mitochondrial DNA damage, which can result in vascular inflammation and atherosclerosis. Finally, novel therapeutic approaches to reduce vascular damage caused by chronic inflammation using microRNA and nano-medicine technology, are discussed.YC is supported by a project grant from the ESRC for her doctoral studies at the University of Cambridge. GT was supported by the BBSRC Doctoral Training Award and Assistant Professorships from The Croucher Foundation of Hong Kong
Monolithically Integrated InAs/GaAs Quantum Dot Mid-Infrared Photodetectors on Silicon Substrates
High-performance, multispectral, and large-format infrared focal plane arrays are the long-demanded third-generation infrared technique for hyperspectral imaging, infrared spectroscopy, and target identification. A promising solution is to monolithically integrate infrared photodetectors on a silicon platform, which offers not only low-cost but high-resolution focal plane arrays by taking advantage of the well-established Si-based readout integrated circuits. Here, we report the first InAs/GaAs quantum dot (QD) infrared photodetectors monolithically integrated on silicon substrates by molecular beam epitaxy. The III–V photodetectors are directly grown on silicon substrates by using a GaAs buffer, which reduces the threading dislocation density to ∼106 cm–2. The high-quality QDs grown on Si substrates have led to long photocarrier relaxation time and low dark current density. Mid-infrared photodetection up to ∼8 μm is also achieved at 80 K. This work demonstrates that III–V photodetectors can directly be integrated with silicon readout circuitry for realizing large-format focal plane arrays as well as mid-infrared photonics in silicon
Gender-Related Differences in the Prevalence of Cardiovascular Disease Risk Factors and their Correlates in Urban Tanzania.
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Urban areas in Africa suffer a serious problem with dual burden of infectious diseases and emerging chronic diseases such as cardiovascular diseases (CVD) and diabetes which pose a serious threat to population health and health care resources. However in East Africa, there is limited literature in this research area. The objective of this study was to examine the prevalence of cardiovascular disease risk factors and their correlates among adults in Temeke, Dar es Salaam, Tanzania. Results of this study will help inform future research and potential preventive and therapeutic interventions against such chronic diseases. The study design was a cross sectional epidemiological study. A total of 209 participants aged between 44 and 66 years were included in the study. A structured questionnaire was used to evaluate socioeconomic and lifestyle characteristics. Blood samples were collected and analyzed to measure lipid profile and fasting glucose levels. Cardiovascular risk factors were defined using World Health Organization criteria. The age-adjusted prevalence of obesity (BMI > or = 30) was 13% and 35%, among men and women (p = 0.0003), respectively. The prevalence of abdominal obesity was 11% and 58% (p < 0.0001), and high WHR (men: >0.9, women: >0.85) was 51% and 73% (p = 0.002) for men and women respectively. Women had 4.3 times greater odds of obesity (95% CI: 1.9-10.1), 14.2-fold increased odds for abdominal adiposity (95% CI: 5.8-34.6), and 2.8 times greater odds of high waist-hip-ratio (95% CI: 1.4-5.7), compared to men. Women had more than three-fold greater odds of having metabolic syndrome (p = 0.001) compared to male counterparts, including abdominal obesity, low HDL-cholesterol, and high fasting blood glucose components. In contrast, female participants had 50% lower odds of having hypertension, compared to men (95%CI: 0.3-1.0). Among men, BMI and waist circumference were significantly correlated with blood pressure, triglycerides, total, LDL-, and HDL-cholesterol (BMI only), and fasting glucose; in contrast, only blood pressure was positively associated with BMI and waist circumference in women. The prevalence of CVD risk factors was high in this population, particularly among women. Health promotion, primary prevention, and health screening strategies are needed to reduce the burden of cardiovascular disease in Tanzania.\u
A Transfer Matrix Method for Resonances in Randall-Sundrum Models
In this paper we discuss in detail a numerical method to study resonances in
membranes generated by domain walls in Randall-Sundrum-like scenarios. It is
based on similar works to understand the quantum mechanics of electrons subject
to the potential barriers that exist in heterostructures in semiconductors.
This method was used recently to study resonances of a three form field and
lately generalized to arbitrary forms. We apply it to a lot of important
models, namely those that contain the Gauge, Gravity and Spinor fields. In many
cases we find a rich structure of resonances which depends on the parameters
involved.Comment: 25 pages, 17 figure
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