Search results for: vulval skin condition

Authors: Junwon Seo, Bipin Adhikari, Euiseok Jeong

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This paper is intended to evaluate the structural performance of welded electronic road signs under various damage scenarios (DSs) using a finite element (FE) model calibrated with full-scale ultimate load testing results. The tested electronic road sign specimen was built with a back skin made of 5052 aluminum and two channels and a frame made of 6061 aluminum, where the back skin was connected to the frame by welding. The size of the tested specimen was 1.52 m long, 1.43 m wide, and 0.28 m deep. An actuator applied vertical loads at the center of the back skin of the specimen, resulting in a displacement of 158.7 mm and an ultimate load of 153.46 kN. Using these testing data, generation and calibration of a FE model of the tested specimen were executed in ABAQUS, indicating that the difference in the ultimate load between the calibrated model simulation and full-scale testing was only 3.32%. Then, six different DSs were simulated where the areas of the welded connection in the calibrated model were diminished for the DSs. It was found that the corners at the back skin-frame joint were prone to connection failure for all the DSs, and failure of the back skin-frame connection occurred remarkably from the distant edges.

Keywords: computational analysis, damage scenarios, electronic road signs, finite element, welded connections

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Authors: Nino Tsamalaidze

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Cold plasma is an ionized neutral gas with a temperature of 30-40 degrees, but the impact of HP includes not only gas, but also active molecules, charged particles, heat and UV radiation of low power The main goal of the technology we describe is to launch the natural function of skin regeneration and improve the metabolism inside, which leads to a huge effect of rejuvenation. In particular: eliminate fine mimic wrinkles; get rid of wrinkles around the mouth (purse-string wrinkles); reduce the overhang of the upper eyelid; eliminate bags under the eyes; provide a lifting effect on the oval of the face; reduce stretch marks; shrink pores; even out the skin, reduce the appearance of acne, scars; remove pigmentation. A clear indication of the major findings of the study is based on the current patients practice. The method is to use combination of cold plasma and liquid threats. The advantage of cold plasma is undoubtedly its efficiency, the result of its implementation can be compared with the result of a surgical facelift, despite the fact that the procedure is non-invasive and the risks are minimized. Another advantage is that the technique can be applied on the most sensitive skin of the face - these are the eyelids and the space around the eyes. Cold plasma is one of the few techniques that eliminates bags under the eyes and overhanging eyelids, while not violating the integrity of the tissues. In addition to rejuvenation and lifting effect, among the benefits of cold plasma is also getting rid of scars, kuperoze, stretch marks and other skin defects, plasma allows to get rid of acne, seborrhea, skin fungus and even heals ulcers. The cold plasma method makes it possible to achieve a result similar to blepharoplasty. Carried out on the skin of the eyelids, the procedure allows non-surgical correction of the eyelid line in 3-4 sessions. One of the undoubted advantages of this method is a short rehabilitation and rapid healing of the skin.

Keywords: wrinkles, telangiectasia, pigmentation, pore closing

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Authors: Isabel Gouveia

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Antimicrobial textile materials may significantly reduce the risk of infections and because they are able to absorb substances from the skin and release therapeutic compounds to the skin, they can also find applications as complementary therapy of skin-diseases as part of standard management. Although functional textiles may be a promising area in skin disease/injury management, as part of standard management, few offer complementary treatment even though they are well known to reduce scratching and aiding emollient absorption, reducing infection, and alleviating pruritus. The reason for this may rely on the low quality of supporting evidence and negative effect that antimicrobial agents may exert on skin microbiome, as for example additional irritation of the vulnerable skin, and by causing resistant bacteria. Several antimicrobial agents have been tested in textiles: quaternary ammonium compounds, silver, polyhexamethylene-biguanides and triclosan have been used, with success. They have powerful bactericidal activity but the majority have a reduce spectrum of microbial inhibition and may cause skin irritation, ecotoxicity and bacteria resistance. Furthermore, the rising flow of strains resistant to last-resort antibiotics rekindles interest in alternative strategies. In this regard, new functional textiles incorporating highly specific antimicrobial agents towards pathogenic bacteria, are required. Recent research has been conducted on naturally occurring antimicrobials as novel alternatives to antibiotics. Conscious of this need our team firstly reported new approaches using L-cysteine and antimicrobial peptides (AMP). Briefly, we were able to develop different immobilization processes towards 6 Log Reduction against bacteria such as S. aureus and K. pneumoniae. Therefore, here we present several innovative antimicrobial textiles incorporating AMP and L-Cysteine which may open new avenues for the medical textiles market and biomaterials in general. Team references will be discussed as an overview and for comparison purposes in terms of potential therapeutic applications.

Keywords: Antimicrobials, Antimicrobial Textiles, Biomedical Textiles, Biomimetic surface functionalization

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Authors: G. Kontochristopoulos, T. Spiliopoulos, V. Markantoni, E. Platsidaki, A. Kouris, E. Balamoti, C. Bokotas, G. Haidemenos

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Introduction: There is a high patient demand for periorbital rejuvenation since the facial area is often the first to show visible signs of aging. With advancing age, there are sometimes marked changes that occur in the skin, fat, muscle and bone of the periorbital region, resulting to wrinkles and skin laxity. These changes are among the easiest areas to correct using several minimally invasive techniques, which have become increasingly popular over the last decade. Lasers, radiofrequency, botulinum toxin, fat grafting and fillers are available treatments sometimes in combination to traditional blepharoplasty. This study attempts to show the benefits of a minimally invasive approach to periorbital wrinkles and skin laxity that combine microneedling and 10% trichloroacetic acid (TCA) peels. Method: Eleven female patients aged 34-72 enrolled in the study. They all gave informed consent after receiving detailed information regarding the treatment procedure. Exclusion criteria in the study were previous treatment for the same condition in the past six months, pregnancy, allergy or hypersensitivity to the components, infection, inflammation and photosensitivity on the affected region. All patients had diffuse periorbital wrinkles and mild to moderate upper or lower eyelid skin laxity. They were treated with Automatic Microneedle Therapy System-Handhold and topical application of 10% trichloroacetic acid solution to each periorbital area for five minutes. Needling at a 0,25 mm depth was performed in both latelar (x-y) directions. Subsequently, the peeling agent was applied to each periorbital area for five minutes. Patients were subjected to the above combination every two weeks for a series of four treatments. Subsequently they were followed up regularly every month for two months. The effect was photo-documented. A Physician's and a Patient's Global Assessment Scale was used to evaluate the efficacy of the treatment (0-25% indicated poor response, 25%-50% fair, 50%-75% good and 75%-100% excellent response). Safety was assessed by monitoring early and delayed adverse events. Results: At the end of the study, almost all patients demonstrated significant aesthetic improvement. Physicians assessed a fair and a good improvement in 9(81.8% of patients) and 2(18.1% of patients) participants respectively. Patients Global Assessment rated a fair and a good response in 6 (54.5%) and 5 (45.4%) participants respectively. The procedure was well tolerated and all patients were satisfied. Mild discomfort and transient erythema were quite common during or immediately after the procedure, however only temporary. During the monthly follow up, no complications or scars were observed. Conclusions: Microneedling is known as a simple, office–based collagen induction therapy. Low concentration TCA solution applied to the epidermis that has been more permeable by microneedling, can reach the dermis more effectively. In the present study, chemical peels with 10% TCA acted as an adjuvant to microneedling, as it causes controlled skin damage, promoting regeneration and rejuvenation of tissues. This combined therapy improved periorbital fine lines, wrinkles, and overall appearance of the skin. Thus it constitutes an alternative treatment of periorbital skin aging, with encouraging results and minor side-effects.

Keywords: chemical peels, microneedling, periorbital wrinkles, skin laxity

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Authors: Ayat E. Ali, Christeen R. Aziz, Merna A. Helmy, Mohammed M. Malek, Sherif H. El-Gohary

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Goal: Purpose of the project was to make a plastic surgery prediction by using pre-operative images for the plastic surgeries’ patients and to show this prediction on a screen to compare between the current case and the appearance after the surgery. Methods: To this aim, we implemented a software which used data from the internet for facial skin diseases, skin burns, pre-and post-images for plastic surgeries then the post- surgical prediction is done by using K-nearest neighbor (KNN). So we designed and fabricated a smart mirror divided into two parts a screen and a reflective mirror so patient's pre- and post-appearance will be showed at the same time. Results: We worked on some skin diseases like vitiligo, skin burns and wrinkles. We classified the three degrees of burns using KNN classifier with accuracy 60%. We also succeeded in segmenting the area of vitiligo. Our future work will include working on more skin diseases, classify them and give a prediction for the look after the surgery. Also we will go deeper into facial deformities and plastic surgeries like nose reshaping and face slim down. Conclusion: Our project will give a prediction relates strongly to the real look after surgery and decrease different diagnoses among doctors. Significance: The mirror may have broad societal appeal as it will make the distance between patient's satisfaction and the medical standards smaller.

Keywords: k-nearest neighbor (knn), face detection, vitiligo, bone deformity

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Authors: Lavrentiadou S. N., Angelou V., Chatzimisios K., Papazoglou L.

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The aim of this study was the isolation and culture of keratinocytes and fibroblasts from feline skin to ultimately create an artificial engineered skin (including dermis and epidermis) useful for the effective treatment of large cutaneous deficits in cats. Epidermal keratinocytes and dermal fibroblasts were freshly isolated from skin biopsies using an 8 mm biopsy punch obtained from 8 healthy cats that had undergone ovariohysterectomy. The owner’s consent was obtained. All cats had a complete blood count and a serum biochemical analysis and were screened for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) preoperatively. The samples were cut into small pieces and incubated with collagenase (2 mg/ml) for 5-6 hours. Following digestion, cutaneous cells were filtered through a 100 μm cell strainer, washed with DMEM, and grown in DMEM supplemented with 10% FBS. The undigested epidermis was washed with DMEM and incubated with 0.05% Trypsin/0.02% EDTA (TE) solution. Keratinocytes recovered in the TE solution were filtered through a 100 μm and a 40 μm cell strainer and, following washing, were grown on a collagen type I matrix in DMEM: F12 (3:1) medium supplemented with 10% FΒS, 1 μm hydrocortisone, 1 μm isoproterenol and 0.1 μm insulin. Both fibroblasts and keratinocytes were grown in a humidified atmosphere with 5% CO2 at 37oC. The medium was changed twice a week and cells were cultured up to passage 4. Cells were grown to 70-85% confluency, at which point they were trypsinized and subcultured in a 1:4 dilution. The majority of the cells in each passage were transferred to a freezing medium and stored at -80oC. Fibroblasts were frozen in DMEM supplemented with 30% FBS and 10% DMSO, whereas keratinocytes were frozen in a complete keratinocyte growth medium supplemented with 10% DMSO. Both cell types were thawed and successfully grown as described above. Therefore, we can create a bank of fibroblasts and keratinocytes, from which we can recover cells for further culture and use for the generation of skin equivalent in vitro. In conclusion, cutaneous cell isolation and cell culture and expansion were successfully developed. To the authors’ best knowledge, this is the first study reporting isolation and culture of keratinocytes and fibroblasts from feline skin. However, these are preliminary results and thus, the development of autologous-engineered feline skin is still in process.

Keywords: cat, fibroblasts, keratinocytes, skin equivalent, wound

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Authors: Alice Huffman, Joseph Hartland, Sam Gibbs

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Dermatology is often a neglected specialty in low-resource settings, despite the high morbidity associated with skin disease. This becomes even more significant when associated with HIV infection, as dermatological conditions are more common and aggressive in HIV positive patients. African countries have the highest HIV infection rates and skin conditions are frequently misdiagnosed and mismanaged, because of a lack of dermatological training and educational material. The frequent lack of diagnostic tests in the African setting renders basic clinical skills all the more vital. This project aimed to improve diagnosis and treatment of skin disease in the HIV population in a district hospital in Malawi. A basic dermatological clinical tool was developed and produced in collaboration with local staff and based on available literature and data collected from clinics. The aim was to improve diagnostic accuracy and provide guidance for the treatment of skin disease in HIV positive patients. A literature search within Embase, Medline and Google scholar was performed and supplemented through data obtained from attending 5 Antiretroviral clinics. From the literature, conditions were selected for inclusion in the resource if they were described as specific, more prevalent, or extensive in the HIV population or have more adverse outcomes if they develop in HIV patients. Resource-appropriate treatment options were decided using Malawian Ministry of Health guidelines and textbooks specific to African dermatology. After the collection of data and discussion with local clinical and pharmacy staff a list of 15 skin conditions was included and a booklet created using the simple layout of a picture, a diagnostic description of the disease and treatment options. Clinical photographs were collected from local clinics (with full consent of the patient) or from the book ‘Common Skin Diseases in Africa’ (permission granted if fully acknowledged and used in a not-for-profit capacity). This tool was evaluated by the local staff, alongside an educational teaching session on skin disease. This project aimed to reduce uncertainty in diagnosis and provide guidance for appropriate treatment in HIV patients by gathering information into one practical and manageable resource. To further this project, we hope to review the effectiveness of the tool in practice.

Keywords: dermatology, HIV, Malawi, skin disease

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Authors: Phuriwat Laomethakorn, Siritron Samosorn, Ramida Watanapokasin

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Cancer metastasis is the major cause of cancer-related death. Therefore searching for a compound that could inhibit cancer metastasis is necessary. 13-Butoxyberberine bromide is a berberine derivative that has not been reported an anti-metastatic effect on skin cancer cells. This study aimed to investigate the anti-metastatic effect of 13-butoxyberberine bromide on skin cancer A431 cells. The effect of 13-butoxyberberine bromide on A431 cell viability was examined by MTT assay. Suppression of cell migration and invasion in A431 cells were determined by wound healing assay, transwell migration assay, and transwell invasion assay. Metastasis proteins were determined by western blotting. The results demonstrated that 13-butoxyberberine bromide decreased A431 cell viability in a dose-dependent manner. In addition, sub-toxic concentrations of 13-butoxyberberine bromide suppressed cell migration and invasion in A431 cells. In addition, 13-butoxyberberine bromide showed anti-metastatic effects by down-regulated MMP-2 and MMP-9 expression. These findings may be useful in the development of 13-butoxyberberine bromide as an anti-metastatic drug in the future.

Keywords: 13-butoxyberberine bromide, metastasis, skin cancer, MMP

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Authors: Alhage Drammeh

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The research is on the occurrence of certain diseases among children in rural and far-flung parts of the Gambia and the extent to which they are caused by lack of access to clean water. A baseline survey was used to discover, describe, and explain the actual processes. The paper explains the purpose of the research, which is majorly to improve the health condition of children, especially those living in rural communities. The paper also gives a brief overview of the socio-economic situation of The Gambia, emphasizing its status as a Least Developed Country (LDC) and the majority of its population living below the poverty line, with women and children hardest hit. The research used as case studies of two rural communities in the Gambia -Basse Dampha Kunda Village and Foni Besse. Data was collected through oral interviews and medical tests conducted among people in both villages, with an emphasis on children. The demographic detail of those tested is tabulated for a clearer understanding. The results were compared, revealing that skin rashes, hepatitis, and certain other diseases are more prevalent in communities lacking access to safe drinking water. These results were also presented in a tabular form. The study established how some policy failures and neglect on the part of the Government of The Gambia are imperiling the health of many rural dwellers in the country, the most glaring being that the research team was unable to test water samples collected from the two communities, as there are no laboratory reagents for testing water anywhere in The Gambia. Many rural communities lack basic amenities, especially clean and potable water, as well as health facilities. The study findings also highlighted the need for healthcare providers and medical NGOs to voice the plight of rural dwellers and collaborate with the government to set up health facilities in rural areas of The Gambia.

Keywords: jaundice, skin rashes, children, rural communities, the Gambia, causes

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Authors: H. Niranjan, S. Sivasankaran

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Heat and mass transfer near a steady stagnation point boundary layer flow of viscous incompressible fluid through porous media investigates along a vertical plate is thoroughly studied under the presence of magneto hydrodynamic (MHD) effects. The fluid flow is steady, laminar, incompressible and in two-dimensional. The nonlinear differential coupled parabolic partial differential equations of continuity, momentum, energy and specie diffusion are converted into the non-similar boundary layer equations using similarity transformation, which are then solved numerically using the Runge-Kutta method along with shooting method. The effects of the conjugate heat transfer parameter, the porous medium parameter, the permeability parameter, the mixed convection parameter, the magnetic parameter, and the thermal radiation on the velocity and temperature profiles as well as on the local skin friction and local heat transfer are presented and analyzed. The validity of the methodology and analysis is checked by comparing the results obtained for some specific cases with those available in the literature. The various parameters on local skin friction, heat and mass transfer rates are presented in tabular form.

Keywords: MHD, porous medium, slip, convective boundary condition, stagnation point

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Authors: Ormanee Patarathipakorn

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Background: Stress was the major psychological problem that affecting to physical and mental health among undergraduate students. Aim of study was to determine the effective of meditation training program (MTP) for stress reduction measured by biofeedback (BB) machine. Material and Methods: This was quasi-experimental study conducted in Faculty of Dentistry, Thammasat University, Thailand. Study period was between August and December 2023. Participants were the first-year Dentistry students. MTP was concentration meditation (Anapana meditation). Stress measurement was evaluated by using Thai version perceived stress scale (T-PSS-10) was performed at one week before study, 14 and 18 weeks. Stress evaluation by biofeedback machine (skin conductance: SC and skin temperature: ST) were performed at one week before study, 4, 8, 14 and 18 weeks. Data from T-PSS-10 and SC/ST biofeedback were collected and analyzed. Results: A total of 28 subjects were recruited. The mean age of participant was 18.4 years old. Two-thirds (19/28) was female. Stress reduction from MTP was detected since 4 and 8 weeks by STBB and SCBB, respectively. T-PSS 10 scores before MTP, 14 and 18 weeks were 17.7± 5.4, 9.8 ± 3.1 and 8.4 ± 3.1 with statistical significance. Conclusion: Meditation training program could reduce stress and measured by skin conductance and temperature biofeedback.

Keywords: stress, meditation, biofeedback, student

Procedia PDF Downloads 37

Authors: N. Garrós, P. Bustos, N. Beirampour, R. Mohammadi, M. Mallandrich, A.C. Calpena, H. Colom

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Atopic dermatitis (AD) is a persistent skin condition characterized by chronic inflammation caused by an autoimmune response. It is a prevalent clinical issue that requires continual treatment to enhance the patient's quality of life. Systemic therapy often involves the use of glucocorticoids or immunosuppressants to manage symptoms. Our objective was to create and assess topical liposomal formulations containing Baricitinib (BNB), a reversible inhibitor of Janus-associated kinase (JAK), which is involved in various immune responses. These formulations were intended to address flare-ups and improve treatment outcomes for AD. We created three distinct liposomal formulations by combining different amounts of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC), cholesterol (CHOL), and ceramide (CER): (i) pure POPC, (ii) POPC mixed with CHOL (at a ratio of 8:2, mol/mol), and (iii) POPC mixed with CHOL and CER (at a ratio of 3.6:2.4:4.0 mol/mol/mol). We conducted various tests to determine the formulations' skin tolerance, irritancy capacity, and their ability to cause erythema and edema on altered skin. We also assessed the transepidermal water loss (TEWL) and skin hydration of rabbits to evaluate the efficacy of the formulations. Histological analysis, the HET-CAM test, and the modified Draize test were all used in the evaluation process. The histological analysis revealed that liposome POPC and POPC:CHOL avoided any damage to the tissues structures. The HET-CAM test showed no irritation effect caused by any of the three liposomes, and the modified Draize test showed a good Draize score for erythema and edema. Liposome POPC effectively counteracted the impact of xylol on the skin, and no erythema or edema was observed during the study. TEWL values were constant for all the liposomes with similar values to the negative control (within the range 8 - 15 g/h·m2, which means a healthy value for rabbits), whereas the positive control showed a significant increase. The skin hydration values were constant and followed the trend of the negative control, while the positive control showed a steady increase during the tolerance study. In conclusion, the developed formulations containing BNB exhibited no harmful or irritating effects, they did not demonstrate any irritant potential in the HET-CAM test and liposomes POPC and POPC:CHOL did not cause any structural alteration according to the histological analysis. These positive findings suggest that additional research is necessary to evaluate the efficacy of these liposomal formulations in animal models of the disease, including mutant animals. Furthermore, before proceeding to clinical trials, biochemical investigations should be conducted to better understand the mechanisms of action involved in these formulations.

Keywords: baricitinib, HET-CAM test, histological study, JAK inhibitor, liposomes, modified draize test

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Authors: Reena Aggarwal

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The use of textile chemicals in the various pre and post-textile manufacturing processes has made the textile industry conscious of its negative contribution to environmental pollution. Popular environmentally friendly fibers such as recycled polyester and organic cotton have been now increasingly used by fabrics and apparel manufacturers. However, after these textiles or the finished apparel are manufactured, they have to be dyed in the same chemical dyes that are harmful and toxic to the environment. Dyeing is a major area of concern for the environment as well as for people who have chemical sensitivities as it may cause nausea, breathing difficulties, seizures, etc. Ayurvastra or herbal medical textiles are one step ahead of the organic lifestyle, which supports the core concept of holistic well-being and also eliminates the impact of harmful chemicals and pesticides. There is a wide range of herbs that can be used not only for dyeing but also for providing medicinal properties to the textiles like antibacterial, antifungal, antiseptic, antidepressant and for treating insomnia, skin diseases, etc. The concept of herbal dyeing of fabric is to manifest herbal essence in every aspect of clothing, i.e., from production to end-use, additionally to eliminate the impact of harmful chemical dyes and chemicals which are known to result in problems like skin rashes, headache, trouble concentrating, nausea, diarrhea, fatigue, muscle and joint pain, dizziness, difficulty breathing, irregular heartbeat and seizures. Herbal dyeing or finishing on textiles will give an extra edge to the textiles as it adds an extra function to the fabric. The herbal extracts can be applied to the textiles by a simple process like the pad dry cure method and mainly acts on the human body through the skin for aiding in the treatment of disease or managing the medical condition through its herbal properties. This paper, therefore, delves into producing Ayurvastra, which is a perfect amalgamation of cloth and wellness. The aim of the paper is to design and create herbal disposable and non-disposable medical textile products acting mainly topically (through the skin) for providing medicinal properties/managing medical conditions. Keeping that in mind, a range of antifungal socks and antibacterial napkins treated with turmeric and aloe vera were developed, which are recommended for the treatment of fungal and bacterial infections, respectively. Both Herbal Antifungal socks and Antibacterial napkins have proved to be efficient enough in managing and treating fungal and bacterial infections of the skin, respectively.

Keywords: ayurvastra, ayurveda, herbal, pandemic, sustainable

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Authors: Margherita Cardellini

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To our knowledge, dark skinned children are often victims of discrimination from adults and society, but few studies specifically focus on skin color discrimination on children coming from the same children. Even today, the 'color blind children' ideology is widespread among adults, teachers, and educators and maybe also among scholars, which seem really careful about study expressions of racism in childhood. This social and cultural belief let people think that all the children, because of their age and their brief experience in the world, are disinterested in skin color. Sometimes adults think that children are even incapable of perceiving skin colors and that it could be dangerous to talk about melaninic differences with them because they finally could notice this difference, producing prejudices and racism. Psychology and neurology research projects are showing for many years that even the newborns are already capable of perceiving skin color and ethnic differences by the age of 3 months. Starting from this theoretical framework we conducted a research project to understand if and how primary school children talk about skin colors, picking up any stereotypes or prejudices. Choosing to use the focus group as a methodology to stimulate the group dimension and interaction, several stories about skin color discrimination's episodes within their classroom or school have emerged. Using the photo elicitation technique we chose to stimulate talk about the research object, which is the skin color, asking the children what was ‘the first two things that come into your mind’ when they look the photographs presented during the focus group, which represented dark and light skinned women and men. So, this paper will present some of these stories about episodes of discrimination with an escalation grade of proximity related to the discriminatory act. It will be presented a story of discrimination happened within the school, in an after-school daycare, in the classroom and even episode of discrimination that children tell during the focus groups in the presence of the discriminated child. If it is true that the Declaration of the Right of the Child state that every child should be discrimination free, it’s also true that every adult should protect children from every form of discrimination. How, as adults, can we defend children against discrimination if we cannot admit that even children are potential discrimination’s actors? Without awareness, we risk to devalue these episodes, implicitly confident that the only way to fight against discrimination is to keep her quiet. The right not to be discriminated goes through the right to talk about its own experiences of discrimination and the right to perceive the unfairness of the constant depreciation about skin color or any element of physical diversity. Intercultural education could act as spokesperson for this mission in the belief that difference and plurality could really become elements of potential enrichment for humanity, starting from children.

Keywords: colorism, experiences of discrimination, primary school children, skin color discrimination

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Authors: Afolabi O.J, Simon-Oke I.A., Oniya M.O., Okaka C.E.

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River blindness is a skin, and an eye disease caused by Onchocerca volvulus and vectored by a female hematophagous blackfly. The study aims to evaluate the distribution of the clinical signs of river blindness and the efficacy of ivermectin in the treatment of river blindness in Idogun. Observational studies in epidemiology that involve the use of a structured questionnaire to obtain useful epidemiological information from the respondents, physical assessment via palpation from head to ankle was used to assess clinical signs from the respondents and skin snip test was used to evaluate the prevalence of the disease. The efficacy of the drug was evaluated and expressed in percentages. One hundred and ninety-two (192) out of the 384 respondents examined, showed various signs of river blindness. However, it was only 108 (28.1%) respondents with the clinical signs that demonstrated Onchocerca volvulus microfilariae in their skin snips. The clinical signs observed among the respondents include skin depigmentation such as dermatitis, leopard skin, papules, pruritus and self-inflicted injury, while ocular symptoms include cataract, ocular lesion and partial blindness. Among these clinical signs, papules, and pruritus were the most dominant in the community. The prevalence of the clinical signs was observed to vary significantly among the age groups and gender (P<0.05). The efficacy of the drug after 6 and 12 months of treatments shows that the drug is more effective at age groups 10-50 years than the age groups 51-90 years. Ivermectin is observed to be efficacious in the treatment of the disease. However, to achieve eradication of the disease, the drug may be administered at 0.15mg/kg twice a year.

Keywords: riverblindness, clinical signs, ivermectin, Idogun

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Authors: D. Glamowska, K. Szymkowska, K. Mojsiewicz- Pieńkowska, K. Cal, Z. Jankowski

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Introduction: The integrity of the outermost layer of skin (stratum corneum) is vital to the penetration of various compounds, including toxic substances. Barrier function of skin depends of its structure. The barrier function of the stratum corneum is provided by patterned lipid lamellae (binlayer). However, a lot of substances, including the low molecular methyl siloxanes (volatile methyl siloxanes, VMS) have an impact on alteration the skin barrier due to damage of stratum corneum structure. VMS belong to silicones. They are widely used in the pharmaceutical as well as cosmetic industry. Silicones fulfill the role of ingredient or excipient in medicinal products and the excipient in personal care products. Due to the significant human exposure to this group of compounds, an important aspect is toxicology of the compounds and safety assessment of products. Silicones in general opinion are considered as a non-toxic substances, but there are some data about their negative effect on living organisms through the inhaled or oral application. However, the transdermal route has not been described in the literature as a possible alternative route of penetration. The aim of the study was to verify the possibility of penetration of the stratum corneum, further permeation into the deeper layers of the skin (epidermis and dermis) as well as to the fluid acceptor by VMS. Methods: Research methodology was developed based on the OECD and WHO guidelines. In ex-vivo study, the fluorescence microscope and ATR FT-IR spectroscopy was used. The Franz- type diffusion cells were used to application of the VMS on the sample of human skin (A=0.65 cm) for 24h. The stratum corneum at the application site was tape-stripped. After separation of epidermis, relevant dyes: fluorescein, sulforhodamine B, rhodamine B hexyl ester were put on and observations were carried in the microscope. To confirm the penetration and permeation of the cyclic or linear VMS and thus the presence of silicone in the individual layers of the skin, spectra ATR FT-IR of the sample after application of silicone and H2O (control sample) were recorded. The research included comparison of the intesity of bands in characteristic positions for silicones (1263 cm-1, 1052 cm-1 and 800 cm-1). Results: and Conclusions The results present that cyclic and linear VMS are able to overcome the barrier of the skin. Influence of them on damage of corneocytes of the stratum corneum was observed. This phenomenon was due to distinct disturbances in the lipid structure of the stratum corneum. The presence of cyclic and linear VMS were identified in the stratum corneum, epidermis as well as in the dermis by both fluorescence microscope and ATR FT-IR spectroscopy. This confirms that the cyclic and linear VMS can penetrate to stratum corneum and permeate through the human skin layers. Apart from this they cause changes in the structure of the skin. Results show to possible absorption into the blood and lymphathic vessels by the VMS with linear and cyclic structure.

Keywords: low molecular methyl siloxanes, volatile methyl siloxanes, linear and cyclic siloxanes, skin penetration, skin permeation

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Authors: Hanan M. Taleb

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Energy consumption associated with buildings has a significant impact on the environment. To that end, and as a transaction between the inside and outside and between the building and urban space, the building skin plays an especially important role. It provides protection from the elements; demarcates private property and creates privacy. More importantly, it controls the admission of solar radiation. Therefore, designing the building skin sustainably will help to achieve optimal performance in terms of both energy consumption and thermal comfort. Unfortunately, with accelerating construction expansion, many recent buildings do not pay attention to the importance of the envelope design. This piece of research will highlight the importance of this part of the creation of buildings by providing evidence of a significant reduction in energy consumption if the envelopes are redesigned. Consequently, the aim of this paper is to enhance the performance of the hospital envelope in order to achieve sustainable performance. A hospital building sited in Abu Dhabi, in the UAE, has been chosen to act as a case study. A detailed analysis of the annual energy performance of the case study will be performed with the use of a computerised simulation; this is in order to explore their energy performance shortcomings. The energy consumption of the base case will then be compared with that resulting from the new proposed building skin. The results will inform architects and designers of the savings potential from various strategies.

Keywords: ASHREA, building skin, building envelopes, hospitals, Abu Dhabi, UAE, IES software

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Authors: Sunil Kumar, Rajesh Sharma

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Toxic epidermal necrolysis, pruritis, rashes, lichen planus like eruption, hyper pigmentation of skin are rare toxic effects of choloroquine used over a long time. Skin and mucus membrane hyper pigmentation is generally of a bluish black or grayish color and irreversible after discontinuation of the drug. According to Ayurveda, Dushivisha is the name given to any poisonous substance which is not fully endowed with the qualities of poison by nature (i.e. it acts as an impoverished or weak poison) and because of its mild potency, it remains in the body for many years causing various symptoms, one among them being discoloration of skin.The objective of this case report is to investigate the effect of Ayurvedic management of chloroquine induced hyper-pigmentation on the line of treatment of Dushivisha. Case Report: A 26-year-old female was suffering from hyper-pigmentation of the skin over the neck, forehead, temporo-mandibular joints, upper back and posterior aspect of both the arms since 8 years had history of taking Chloroquine came to Out Patient Department of National Institute of Ayurveda, Jaipur, India in Jan. 2015. The routine investigations (CBC, ESR, Eosinophil count) were within normal limits. Punch biopsy skin studied for histopathology under hematoxylin and eosin staining showed epidermis with hyper-pigmentation of the basal layer. In the papillary dermis as well as deep dermis there were scattered melanophages along with infiltration by mononuclear cells. There was no deposition of amyloid-like substances. These histopathological findings were suggestive of Chloroquine induced hyper-pigmentation. The case was treated on the line of treatment of Dushivisha and was given Vamana and Virechana (therapeutic emesis and purgation) every six months followed by Snehana karma (oleation therapy) with Panchatikta Ghrit and Swedana (sudation). Arogyavardhini Vati -1 g, Dushivishari Vati 500 mg, Mahamanjisthadi Quath 20 ml were given twelve hourly and Aragwadhadi Quath 25 ml at bed time orally. The patient started showing lightening of the pigments after six months and almost complete remission after 12 months of the treatment. Conclusion: This patient presented with the Dushivisha effect of Chloroquineandwas administered two relevant procedures from Panchakarma viz. Vamana and Virechana. Both Vamana and Virechanakarma here referred to Shodhana karma (purification procedures) eliminates accumulated toxins from the body. In this process, oleation dislodge the toxins from the tissues and sudation helps to bring them to the alimentary tract. The line of treatment did not target direct hypo pigmentary effects; rather aimed to eliminate the Dushivisha. This gave promising results in this condition.

Keywords: Ayurveda, chloroquine, Dushivisha, hyper-pigmentation

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Authors: Aurea C. L. Lacerda, Paulo R. H. Moreno, Bruna M. P. Vianna, Cristina H. R. Serra, Airton Martin, André R. Baby, Vladi O. Consiglieri, Telma M. Kaneko

Abstract:

The modified Franz cell is the most widely used model for in vitro permeation studies, however it still presents some disadvantages. Thus, some alternative methods have been developed such as Skin PAMPA, which is a bio- artificial membrane that has been applied for skin penetration estimation of xenobiotics based on HT permeability model consisting. Skin PAMPA greatest advantage is to carry out more tests, in a fast and inexpensive way. The membrane system mimics the stratum corneum characteristics, which is the primary skin barrier. The barrier properties are given by corneocytes embedded in a multilamellar lipid matrix. This layer is the main penetration route through the paracellular permeation pathway and it consists of a mixture of cholesterol, ceramides, and fatty acids as the dominant components. However, there is no consensus on the membrane composition. The objective of this work was to compare the performance among different bio-artificial membranes for studying the permeation in skin PAMPA system. Material and methods: In order to mimetize the lipid composition`s present in the human stratum corneum six membranes were developed. The membrane composition was equimolar mixture of cholesterol, ceramides 1-O-C18:1, C22, and C20, plus fatty acids C20 and C24. The membrane integrity assay was based on the transport of Brilliant Cresyl Blue, which has a low permeability; and Lucifer Yellow with very poor permeability and should effectively be completely rejected. The membrane characterization was performed using Confocal Laser Raman Spectroscopy, using stabilized laser at 785 nm with 10 second integration time and 2 accumulations. The membrane behaviour results on the PAMPA system were statistically evaluated and all of the compositions have shown integrity and permeability. The confocal Raman spectra were obtained in the region of 800-1200 cm-1 that is associated with the C-C stretches of the carbon scaffold from the stratum corneum lipids showed similar pattern for all the membranes. The ceramides, long chain fatty acids and cholesterol in equimolar ratio permitted to obtain lipid mixtures with self-organization capability, similar to that occurring into the stratum corneum. Conclusion: The artificial biological membranes studied for Skin PAMPA showed to be similar and with comparable properties to the stratum corneum.

Keywords: bio-artificial membranes, comparison, confocal Raman, skin PAMPA

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Authors: Sayed Ahmed El Sayed, Osama M. Mesalhy, Mohamed A. Abdelatief

Abstract:

A numerical study has been conducted to clarify fluid flow characteristics, pressure distributions, and skin friction coefficient over a wing-shaped tubes bundle in staggered arrangement with the placement of longitudinal fins (LF) at downstream position of the tube. The air-side Rea were at 1.8 x 103 to 9.7 x 103. The tubes bundle were employed with various fin height [hf] and fin thickness (δ) from (2 mm ≤ hf ≤ 12 mm) and (1.5 mm ≤ δ ≤ 3.5 mm) respectively at the considered Rea range. The flow pattern around the staggered wing-shaped tubes bundle was predicted using the commercial CFD FLUENT 6.3.26 software package. The distribution of average skin friction coefficient around wing-shaped tubes bundle is studied. Correlation of pressure drop coefficient Pdc and skin friction coefficient (Cf) in terms of Rea, design parameters for the studied cases were presented. Results indicated that the values of Pdc for hf = 6 mm are lower than these of NOF and hf = 2 mm by about 11 % and 13 % respectively for considered Rea range. Cf decreases as Rea increases. LFTH with hf = 6 mm offers lower form drag than that with hf = 12 mm and that of NOF. The lowest values of the pumping power are achieved for arrangements of hf = 6 mm for the considered Rea range. δ has negligible effect on skin friction coefficient, while has a slightly variation in ∆Pa. The wing-shaped tubes bundle heat exchanger with hf = 6 mm has the lowest values of ∆Pa, Pdc, Cf, and pumping power and hence the best performance comparing with the other bundles. Comparisons between the experimental and numerical results of the present study and those obtained by similar previous studies showed good agreements.

Keywords: longitudinal fins, skin friction, flow characteristics, FLUENT, wing-shaped tubes

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Authors: Sara Mota Carmo

Abstract:

Nowadays, there is an increasing demand for buildings to be energetically autonomous through energy generation systems from renewable sources, according to the concept of a net zero energy building (NZEB). In this sense, the present study aims to study the integration of wind energy through piezoelectricity applied to the building skin. As a methodology, a reduced-scale prototype of a building was developed and tested in a wind tunnel, with the four façades monitored by recording the energy produced by each. The applied wind intensities varied between 2m/s and 8m/s and the four façades were compared with each other regarding the energy produced according to the intensity of wind and position in the wind. The results obtained concluded that it was not a sufficient system to generate sources to cover family residential buildings' energy needs. However, piezoelectricity is expanding and can be a promising path for a wind energy system in architecture as a complement to other renewable energy sources.

Keywords: adaptative building skin, kinetic façade, wind energy in architecture, NZEB

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Authors: Minjung Park, Jimin Park, Youngwoon Kim, Hyungseop Han, Myoungryul Ok, Hojeong Jeon, Hyunkwang Seok, Yuchan Kim

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Magnesium is an essential element in human body and has unique characteristics such as bioabsorbable and biodegradable properties. Therefore, there has been much attention on studies on the implants based on magnesium to avoid subsequent surgery. However, high amount of hydrogen gas is generated by relatively severe corrosion of magnesium especially in aqueous condition with chloride ions. And it contributes to the causes of swelling of skin and causes consequent inflammation of soft tissue where is directly in contact with implants. Therefore, there is still concern about the safety of the using biodegradable magnesium alloys, which is limited to various applications. In this study, we analyzed the influence of coenzyme on corrosion behavior of magnesium. The analysis of corrosion rate was held by using Hanks’ balanced salt solution (HBSS) as a body stimulated fluid and in condition of 37°C. Thus, with deferring the concentration of the coenzyme used in this study, corrosion rates from 0.0654ml/ cm² to 0.0438ml/cm² were observed in immersion tests. Also, comparable results were obtained in electrochemical tests. Results showed that hydrogen gas produced from corrosion of magnesium can be controlled.

Keywords: biodegradable magnesium, biomaterials, coenzyme, corrosion

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Authors: S. Zith Dey Babu, S. Kour, S. Verma, C. Verma, V. Pathania, A. Agrawal, V. Chaudhary, A. Manoj Puthur, R. Goyal, A. Pal, T. Danti Dey, A. Kumar, K. Wadhwa, O. Ved

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Background: Skin cancer is now is the buzzing button in the field of medical science. The cyst's pandemic is drastically calibrating the body and well-being of the global village. Methods: The extracted image of the skin tumor cannot be used in one way for diagnosis. The stored image contains anarchies like the center. This approach will locate the forepart of an extracted appearance of skin. Partitioning image models has been presented to sort out the disturbance in the picture. Results: After completing partitioning, feature extraction has been formed by using genetic algorithm and finally, classification can be performed between the trained and test data to evaluate a large scale of an image that helps the doctors for the right prediction. To bring the improvisation of the existing system, we have set our objectives with an analysis. The efficiency of the natural selection process and the enriching histogram is essential in that respect. To reduce the false-positive rate or output, GA is performed with its accuracy. Conclusions: The objective of this task is to bring improvisation of effectiveness. GA is accomplishing its task with perfection to bring down the invalid-positive rate or outcome. The paper's mergeable portion conflicts with the composition of deep learning and medical image processing, which provides superior accuracy. Proportional types of handling create the reusability without any errors.

Keywords: computer-aided system, detection, image segmentation, morphology

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Authors: Giriprasath Ramanathan, Sivakumar Singaravelu, M. D. Raja, Uma Tirichurapalli Sivagnanam

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Collagen is the abundant protein found in the skin of the animal body that has been designed to provide adequate structural support for the adhesion of cells. The dressing material widely used for tissue engineering and biomedical application has to posses good swelling and biological property for the absorption of exudates and cell proliferation. Acid solubilised collagen from the fish skin of the Arothron stellatus was extracted. The collagen with hydroxypropyl and carboxy methyl cellulose has the better biological property to enhance the healing efficiency. The inter property of collagen with interesting perspectives in the tissue engineering process leads to the development of biomaterial with natural polymer with biologically derived collagen. Keeping this as an objective, the composite biomaterial was fabricated to improve the wound healing and biological properties. In this study the collagen from Arothron stellatus fish skin (ACO) was uniformly blended separately with hydroxypropyl methyl cellulose (HPMC) and carboxyl methyl cellulose (CMC) as biosheets. The casted biosheets were impregnated with mupirocin to get rid of infection from the microbes. Further, the results obtained from differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile studies and biocompatibility of the biosheets were assessed. The swelling, porosity and degradation of the casted biosheets were studied to make the biosheets as a suitable wound dressing material. ACO-HPMC and ACO-CMC biosheets both showed good results, but ACO-HPMC biosheet showed better results than ACO-CMC and hence it can be used as a potential dermal substitute in skin tissue engineering.

Keywords: arothron stellatus, biocompatibility, collagen, tensile strenght

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Authors: K. M. Somawathie, V. Rizliya, H. A. M. Wickrmasinghe, Terrence Madhujith

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The main objective of our study was to determine the in vitro antioxidant and DNA protectant activity of aqueous extract of S. melongena with different skin colors; dark purple (DP), moderately purple (MP), light purple (LP) and purple and green (PG). The antioxidant activity was evaluated using the DPPH and ABTS free radical scavenging assay, ferric reducing antioxidant power (FRAP), ferric thiocyanate (FTC) and the egg yolk model. The effectiveness of eggplant extracts against radical induced DNA damage was also determined. There was a significant difference (p < 0.0001) between the skin color and antioxidant activity. TPC and FRAP values of eggplant extracts ranged from 48.67±0.27-61.11±0.26 (mg GAE/100 g fresh weight) and 4.19±0.11-7.46±0.26 (mmol of FeS04/g of fresh weight) respectively. MP displayed the highest percentage of DPPH radical scavenging activity while, DP demonstrated the strongest total antioxidant capacity. In the FTC and egg yolk model, DP and MP showed better antioxidant activity than PG and LP. All eggplant extracts showed potent antioxidant activity in retaining DNA against AAPH mediated radical damage. DP and MP demonstrated better antioxidant activity which may be attributed to the higher phenolic content since a positive correlation was observed between the TPC and the antioxidant parameters.

Keywords: Solanum melongena, skin color, antioxidant, DNA protection, lipid peroxidation

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Authors: Sihao Lin

Abstract:

Objectives: Infrared thermography (IRT) has been little documented in the objective measurement of ergonomic exposure. We aimed to examine the association between different ergonomic exposures and low back skin temperature measured by IRT. Methods: A total of 114 subjects among sedentary students, sports students and cleaning workers were selected as different ergonomic exposure levels. Low back skin temperature was measured by infrared thermography before and post ergonomic exposure. Ergonomic exposure was assessed by Quick Exposure Check (QEC) and quantitative scores were calculated on the low back. Multiple regressions were constructed to examine the possible associations between ergonomic risk exposures and the skin temperature over the low back. Results: Compared to the two student groups, clean workers had significantly higher ergonomic exposure scores on the low back. The low back temperature variations were different among the three groups. The temperature decreased significantly among students with ergonomic exposure (P < 0.01), while it increased among cleaning workers. With adjustment of confounding, the post-exposure temperature and the temperature changes after exposure showed a significantly negative association with ergonomic exposure scores. For maximum temperature, one increasing ergonomic score decreased -0.23◦C (95% CI -0.37, -0.10) of temperature after ergonomic exposure over the low back. Conclusion: There was a significant association between ergonomic exposures and infrared thermal temperature over low back. IRT could be used as an objective assessment of ergonomic exposure on the low back.

Keywords: ergonomic exposure, infrared thermography, musculoskeletal disorders, skin temperature, low back

Procedia PDF Downloads 103

Authors: Shivankar Agrawal, Sunil Kumar Deshmukh, Colin Barrow, Alok Adholeya

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Millions of people worldwide are affected by infectious diseases caused by bacteria and fungi. Skin and skin structure infections (SSSI) represent a significant category of infectious disease. Unexpectedly, many pathogens have developed resistance towards current antibiotics and over the time this problem has become more and more serious. All these new problems necessitate the continuous search for novel and alternative antibiotics and antifungals. The aim of our research is the screening of extracts of marine fungi for their antibacterial activity against bacteria causing skin and wound infection in humans. A total of 40 marine samples were collected from west coast and Andaman Island of India and 35 morphologically different marine fungi were isolated using natural sea water medium. Among 35 marine fungi, eight isolates exhibited significant antimicrobial activity against human pathogens. In the course of systematic screening program for bioactive marine fungi, strain 'D5' was found to be most potent strain with MIC value of 1 mg/mL, which was morphologically identified as Simplicillium lamellicola. The effects of the most active crude extracts against their susceptible test microorganisms were also investigated by SEM analysis. Purification and characterization of crude extracts for identification of active lead molecule is under process. The results of diversity and antimicrobial activity have increased the scope of finding industrially important marine fungi from Indian marine environments and these organisms could be vital sources for the discovery of pharmaceutically useful molecules.

Keywords: antimicrobial activity, antibiotic, marine fungi, skin infections

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Authors: O. Hakim, K. Hart, P. McCabe, J. Berry, L. E. Rhodes, N. Spyrou, A. Alfuraih, S. Lanham-New

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It is known that skin pigmentation reduces the penetration of ultraviolet radiation (UVR) and thus photosynthesis of 25(OH)D. However, the ethnic differences in 25(OH)D production remain to be fully elucidated. This study aimed to investigate the differences in vitamin D production between Asian and Caucasian postmenopausal women, in response to a defined, controlled UVB exposure. Seventeen women; nine white Caucasian (skin phototype II and III), eight South Asian women (skin phototype IV and V) participated in the study, acting as their controls. Three blood samples were taken for measurement of 25(OH)D during the run-in period (nine days, no sunbed exposure) after which all subjects underwent an identical UVR exposure protocol irrespective of skin colour (nine days, three sunbed sessions: 6, 8 and 8 minutes respectively with approximately 80% of body surface exposed). Skin tone was measured four times during the study. Both groups showed a gradual increase in 25(OH)D with final levels significantly higher than baseline (p<0.01). 25(OH)D concentration mean from a baseline of 43.58±19.65 to 57.80±17.11 nmol/l among Caucasian and from 27.03±23.92 to 44.73±17.74 nmol/l among Asian women. The baseline status of vitamin D was classified as deficient among the Asian women and insufficient among the Caucasian women. The percentage increase in vitamin D3 among Caucasians was 39.86% (21.02) and 207.78% (286.02) in Asian subjects respectively. This greater response to UVR exposure reflects the lower baseline levels of the Asian subjects. The mixed linear model analysis identified a significant effect of duration of UVR exposure on the production of 25(OH)D. However, the model shows no significant effect of ethnicity and skin tone on the production of 25(OH)D. These novel findings indicate that people of Asian ethnicity have the full capability to produce a similar amount of vitamin D compared to the Caucasian group; initial vitamin D concentration influences the amount of UVB needed to reach equal serum concentrations.

Keywords: ethnicity, Caucasian, South Asian, vitamin D, ultraviolet radiation, UVR

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Authors: Saleh Alshehri

Abstract:

Human skin detection is a vital step in many applications. Some of the applications are critical especially those related to security. This leverages the importance of a high-performance detection algorithm. To validate the accuracy of the algorithm, image databases are usually used. However, the suitability of these image databases is still questionable. It is suggested that the suitability can be measured mainly by the span the database covers of the color space. This research investigates the validity of three famous image databases.

Keywords: image databases, image processing, pattern recognition, neural networks

Procedia PDF Downloads 271

Authors: K. K. Balavenkatraman, B. Bertschi, K. Bigot, A. Grevot, A. Doelemeyer, S. D. Chibout, A. Wolf, F. Pognan, N. Manevski, O. Kretz, P. Swart, K. Litherland, J. Ashton-Chess, B. Ling, R. Wettstein, D. J. Schaefer

Abstract:

Skin toxicity is poorly detected during preclinical studies, and drug-induced side effects in humans such as rashes, hyperplasia or more serious events like bullous pemphigus or toxic epidermal necrolysis represent an important hurdle for clinical development. In vitro keratinocyte-based epidermal skin models are suitable for the detection of chemical-induced irritancy, but do not recapitulate the biological complexity of full skin and fail to detect potential serious side-effects. Normal healthy skin explants may represent a valuable complementary tool, having the advantage of retaining the full skin architecture and the resident immune cell diversity. This study investigated several conditions for the maintenance of good morphological structure after several days of culture and the retention of phase II metabolism for 24 hours in skin explants in vitro. Human skin samples were collected with informed consent from patients undergoing plastic surgery and immediately transferred and processed in our laboratory by removing the underlying dermal fat. Punch biopsies of 4 mm diameter were cultured in an air-liquid interface using transwell filters. Different cultural conditions such as the effect of calcium, temperature and cultivation media were tested for a period of 14 days and explants were histologically examined after Hematoxylin and Eosin staining. Our results demonstrated that the use of Williams E Medium at 32°C maintained the physiological integrity of the skin for approximately one week. Upon prolonged incubation, the upper layers of the epidermis become thickened and some dead cells are present. Interestingly, these effects were prevented by addition of EGFR inhibitors such as Afatinib or Erlotinib. Phase II metabolism of the skin such as glucuronidation (4-methyl umbeliferone), sulfation (minoxidil), N-acetyltransferase (p-toluidene), catechol methylation (2,3-dehydroxy naphthalene), and glutathione conjugation (chlorodinitro benzene) were analyzed by using LCMS. Our results demonstrated that the human skin explants possess metabolic activity for a period of at least 24 hours for all the substrates tested. A time course for glucuronidation with 4-methyl umbeliferone was performed and a linear correlation was obtained over a period of 24 hours. Longer-term culture studies will indicate the possible evolution of such metabolic activities. In summary, these results demonstrate that human skin explants maintain a normal structure for several days in vitro and are metabolically active for at least the first 24 hours. Hence, with further characterisation, this model may be suitable for the study of drug-induced toxicity.

Keywords: human skin explant, phase II metabolism, epidermal growth factor receptor, toxicity

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