Metamaterial Biosensor on THz Regime for Early Detection and Quantitative Analysis of Skin Cancer

'Terahertz imaging exhibits significant potential in the early detection of skin cancer. This work introduces a metamaterial unit cell that operates in the terahertz (THz) band for non-invasive contact-based detection of skin cancer. The sensor relies solely on the reflection coefficient response, offering high sensitivity to subtle changes in tissue properties without complex signal processing, making it potentially cost-effective and simpler to implement for early cancer detection. The simulations utilised 3D models representing normal skin, basal cell carcinoma (BCC), and melanoma skin types. The dielectric characteristics of the samples were determined using the Double Debye model. The simulation demonstrated that the metamaterial design exhibited properties of a double negative material at the specific frequency of 1.15 THz. Following skin contact and malignancy, the reflectance coefficient exhibited a shift towards lower frequencies. The melanoma sample exhibited the most significant shift in resonance towards lower frequencies, indicating a more severe form of cancer compared to BCC. Furthermore, it was observed that the disparity in resonance frequencies between normal skin and malignant skin increased as the thickness of the sample increased. The sensor’s sensitivity in identifying cancer thickness was measured at 9.25 GHz/µm for basal cell carcinoma (BCC) and 10.2 GHz/µm for melanoma. In addition, the linear regression analysis demonstrated a strong correlation between the resonance frequency and the variation in cancer thickness, as indicated by the R2 values of 0.9948 and 0.9947 for BCC and melanoma, respectively. These findings demonstrate that the sensor can detect skin cancer of any severity at the initial stages of its development

N-acetylcysteine (NAC) ameliorates Epstein-Barr virus latent membrane protein 1 induced chronic inflammation

Chronic inflammation results when the immune system responds to trauma, injury or infection and the response is not resolved. It can lead to tissue damage and dysfunction and in some cases predispose to cancer. Some viruses (including Epstein-Barr virus (EBV)) can induce inflammation, which may persist even after the infection has been controlled or cleared. The damage caused by inflammation, can itself act to perpetuate the inflammatory response. The latent membrane protein 1 (LMP1) of EBV is a pro-inflammatory factor and in the skin of transgenic mice causes a phenotype of hyperplasia with chronic inflammation of increasing severity, which can progress to pre-malignant and malignant lesions. LMP1 signalling leads to persistent deregulated expression of multiple proteins throughout the mouse life span, including TGFα S100A9 and chitinase-like proteins. Additionally, as the inflammation increases, numerous chemokines and cytokines are produced which promulgate the inflammation. Deposition of IgM, IgG, IgA and IgE and complement activation form part of this process and through genetic deletion of CD40, we show that this contributes to the more tissue-destructive aspects of the phenotype. Treatment of the mice with N-acetylcysteine (NAC), an antioxidant which feeds into the body’s natural redox regulatory system through glutathione synthesis, resulted in a significantly reduced leukocyte infiltrate in the inflamed tissue, amelioration of the pathological features and delay in the inflammatory signature measured by in vivo imaging. Reducing the degree of inflammation achieved through NAC treatment, had the knock on effect of reducing leukocyte recruitment to the inflamed site, thereby slowing the progression of the pathology. These data support the idea that NAC could be considered as a treatment to alleviate chronic inflammatory pathologies, including post-viral disease. Additionally, the model described can be used to effectively monitor and accurately measure therapies for chronic inflammation

Encapsulation of expansive powder minerals within a concentric glass capsule system for self-healing concrete

This study presents the application of encapsulated expansive powder minerals (magnesium oxide, bentonite and quicklime) for self-healing of cement-based mortars. A system of concentric glass macrocapsules was used to envelope the expansive minerals (outer capsule) and water (inner capsule). Mortar samples containing concentric macrocapsules with different mineral combinations were cracked and healed under three different curing regimes; ambient conditions, high humidity exposure and immersed in water. Self-healing was assessed based on visual crack sealing, mechanical strength recovery and improvement in durability investigated by means of capillary sorption tests. Micro-structural analysis of the healing materials was investigated using FT-IR, XRD and SEM-EDX for exploring self-healing kinetics. Immersed in water have yielded the optimum healing efficiency with ∼95% crack sealing and ∼25% strength recovery in 28 days. Data showed an increasing trend in 56 days for both crack sealing and load recovery. The improvement in terms of capillary absorption of healed samples was also significant after 28 days of healing. Self-healing kinetics revealed that the expansive minerals were hydrated in the initial healing period and slowly carbonated over time until the peripheral crack zone became adequately water tight.The support of Islamic Development Bank (IDB) scholarship collaborating with Cambridge Overseas Trust for the first author’s PhD research is greatly appreciated. Moreover, financial support from the Engineering and Physical Sciences Research Council (EPSRC) for this study (Project Ref. EP/K026631/1 – “Materials for Life”) is also gratefully acknowledged.This is the final version of the article. It first appeared from Elsevier at http://dx.doi.org/10.1016/j.conbuildmat.2016.06.030

Autogenous self-healing of cement with expansive minerals-I: Impact in early age crack healing

This study investigates the impact of expansive minerals, namely magnesium oxide, bentonite clay, and quicklime on the early age autogenous self-healing capacity of Portland cement (PC) paste. Individual mineral dosage in PC was studied comprehensively together with several multiple mineral combinations. The study also covers a brief state of the art on autogenous self-healing and the use of minerals. The healing performance was compared using flexural strength recovery, crack sealing, and permeability tests. Materials microstructural investigations were carried out using XRD, TGA and SEM-EDX. The hydrated and swelling products of expansive minerals have effectively contributed to the production of healing materials. Cracks in the range of 150 µm healed efficiently in a mineral containing mixes within 28 days. Self-healing recovery was triggered through the crack bridging (strength recovery), sealing (physical closer of cracks through crystallisation) and durability performance improvement.The support of Islamic Development Bank (IDB) scholarship collaborating with Cambridge Overseas Trust for the first author’s PhD research is greatly appreciated. Moreover, collaboration from the Engineering and Physical Sciences Research Council (EPSRC) for this study (Project Ref. EP/K026631/1 – “Materials for Life: Biomimetic multi-scale damage immunity for construction materials”) is also gratefully acknowledged

A Bayesian framework for the local configuration of retinal junctions

Retinal images contain forests of mutually intersecting and overlapping venous and arterial vascular trees. The geometry of these trees shows adaptation to vascular diseases including diabetes, stroke and hypertension. Segmentation of the retinal vascular network is complicated by inconsistent vessel contrast, fuzzy edges, variable image quality, media opacities, complex intersections and overlaps. This paper presents a Bayesian approach to resolving the con- figuration of vascular junctions to correctly construct the vascular trees. A probabilistic model of vascular joints (terminals, bridges and bifurcations) and their configuration in junctions is built, and Maximum A Posteriori (MAP) estimation used to select most likely configurations. The model is built using a reference set of 3010 joints extracted from the DRIVE public domain vascular segmentation dataset, and evaluated on 3435 joints from the DRIVE test set, demonstrating an accuracy of 95.2%

The Journey of Insulin: Leaving a Legacy as a Medical Student

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THE PREVALENCE OF DYSPLASIA IN COLORECTAL SERRATED/HYPERPLASTIC POLYPS IN OMANI POPULATION

Purpose: Serrated/hyperplastic polyps (SPs) are characterised histologically by sawtooth architecture. Historically, these polyps were considered benign, without malignant potential and thus clinically unimportant. At present, the WHO defines serrated/hyperplastic lesions as heterogeneous group, which include hyperplastic polyps (HP), sessile serrated adenoma (SSA)/polyp and traditional serrated adenoma (TSA). These can have malignant potential. The aim of this study was to evaluate the prevalence of dysplastic changes in SP of colon and rectum of Omani population reported at a tertiary care centre.Methods: The study was conducted in the pathology department of a tertiary care centre including endoscopic polypectomies from colon and rectum of Omani patients presenting to gastroenterology clinic reported between 2014 and 2016, and these were analysed retrospectively for dysplastic changes and their association with different clinical parameters.Results: Dysplasia was seen in 32 of 146 cases (21.9%) and 114 (78.1%) were without dysplasia. Of these dysplastic, biopsies’ only two cases (1.4%) showed high-grade dysplasia and rest 30 (20.5%) low-grade dysplasia. According to the type of polyp, dysplasia was found in TSA 8/21 cases (46.7%) and SSA 9/17 cases (53.3%). Association of dysplasia was more common in the age group of > 50 (15.07%) and male patients (62.5%).Conclusion: SPs are now common findings that a gastroenterologist faces in their daily practice. In our study of Omani population, the prevalence of dysplasia is associated with older age group, male gender, SSA/polyp and traditional serrated adenoma.Key words: Dysplasia. colorectal, polyp