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Sample records for skin sensitization based

  1. Infrared sensing based sensitive skin

    Institute of Scientific and Technical Information of China (English)

    CAO Zheng-cai; FU Yi-li; WANG Shu-guo; JIN Bao

    2006-01-01

    Developed robotics sensitive skin is a modularized, flexible, mini-type array of infrared sensors with data processing capabilities, which can be used to cover the body of a robot. Depending on the infrared sensors and periphery processing circuit, robotics sensitive skin can in real-time provide existence and distance information about obstacles for robots within sensory areas. The methodology of designing sensitive skin and the algorithm of a mass of IR data fusion are presented. The experimental results show that the multi-joint robot with this sensitive skin can work autonomously in an unknown environment.

  2. Skin sensitization: Modeling based on skin metabolism simulation and formation of protein conjugates

    DEFF Research Database (Denmark)

    Dimitrov, Sabcho; Low, Lawrence; Patlewicz, Grace

    2005-01-01

    alerting groups, three-dimensional (3D)-QSARs were developed to describe the multiplicity of physicochemical, steric, and electronic parameters. These 3D-QSARs, so-called pattern recognition-type models, were applied each time a latent alerting group was identified in a parent chemical or its generated...... in the model building. The TIssue MEtabolism Simulator (TIMES) software was used to integrate a skin metabolism simulator and 3D-QSARs to evaluate the reactivity of chemicals thus predicting their likely skin sensitization potency....

  3. A cell-based in vitro alternative to identify skin sensitizers by gene expression

    International Nuclear Information System (INIS)

    Hooyberghs, Jef; Schoeters, Elke; Lambrechts, Nathalie; Nelissen, Inge; Witters, Hilda; Schoeters, Greet; Heuvel, Rosette van den

    2008-01-01

    The ethical and economic burden associated with animal testing for assessment of skin sensitization has triggered intensive research effort towards development and validation of alternative methods. In addition, new legislation on the registration and use of cosmetics and chemicals promote the use of suitable alternatives for hazard assessment. Our previous studies demonstrated that human CD34 + progenitor-derived dendritic cells from cord blood express specific gene profiles upon exposure to low molecular weight sensitizing chemicals. This paper presents a classification model based on this cell type which is successful in discriminating sensitizing chemicals from non-sensitizing chemicals based on transcriptome analysis of 13 genes. Expression profiles of a set of 10 sensitizers and 11 non-sensitizers were analyzed by RT-PCR using 9 different exposure conditions and a total of 73 donor samples. Based on these data a predictive dichotomous classifier for skin sensitizers has been constructed, which is referred to as . In a first step the dimensionality of the input data was reduced by selectively rejecting a number of exposure conditions and genes. Next, the generalization of a linear classifier was evaluated by a cross-validation which resulted in a prediction performance with a concordance of 89%, a specificity of 97% and a sensitivity of 82%. These results show that the present model may be a useful human in vitro alternative for further use in a test strategy towards the reduction of animal use for skin sensitization

  4. Development of an in vitro skin sensitization test based on ROS production in THP-1 cells.

    Science.gov (United States)

    Saito, Kazutoshi; Miyazawa, Masaaki; Nukada, Yuko; Sakaguchi, Hitoshi; Nishiyama, Naohiro

    2013-03-01

    Recently, it has been reported that reactive oxygen species (ROS) produced by contact allergens can affect dendritic cell migration and contact hypersensitivity. The aim of the present study was to develop a new in vitro assay that could predict the skin sensitizing potential of chemicals by measuring ROS production in THP-1 (human monocytic leukemia cell line) cells. THP-1 cells were pre-loaded with a ROS sensitive fluorescent dye, 5-(and 6-)-chloromethyl-2', 7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA), for 15min, then incubated with test chemicals for 30min. The fluorescence intensity was measured by flow cytometry. For the skin sensitizers, 25 out of 30 induced over a 2-fold ROS production at more than 90% of cell viability. In contrast, increases were only seen in 4 out of 20 non-sensitizers. The overall accuracy for the local lymph node assay (LLNA) was 82% for 50 chemicals tested. A correlation was found between the estimated concentration showing 2-fold ROS production in the ROS assay and the EC3 values (estimated concentration required to induce positive response) of the LLNA. These results indicated that the THP-1 cell-based ROS assay was a rapid and highly sensitive detection system able to predict skin sensitizing potentials and potency of chemicals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Performance of a novel keratinocyte-based reporter cell line to screen skin sensitizers in vitro

    International Nuclear Information System (INIS)

    Emter, Roger; Ellis, Graham; Natsch, Andreas

    2010-01-01

    In vitro tests are needed to replace animal tests to screen for the skin sensitization potential of chemicals. Skin sensitizers are electrophilic molecules and the Nrf2-electrophile-sensing pathway comprising the repressor protein Keap1, the transcription factor Nrf2 and the antioxidant response element (ARE) is emerging as a toxicity pathway induced by skin sensitizers. Previously, we screened a large set of chemicals in the reporter cell line AREc32, which contains an eight-fold repeat of the rat GSTA2 ARE-sequence upstream of a luciferase reporter gene in the human breast cancer cell line MCF7. This approach was now further developed to bring it closer to the conditions in the human skin and to propose a fully standardized assay. To this end, a luciferase reporter gene under control of a single copy of the ARE-element of the human AKR1C2 gene was stably inserted into HaCaT keratinocytes. A standard operating procedure was developed whereby chemicals are routinely tested at 12 concentrations in triplicate for significant induction of gene activity. We report results from this novel assay on (i) a list of reference chemicals published by ECVAM, (ii) the ICCVAM list of chemicals for validation of alternative endpoints in the LLNA and (iii) on a more general list of 67 chemicals derived from the ICCVAM database. For comparison, peptide reactivity data are presented for the same chemicals. The results indicate a good predictive value of this approach for hazard identification. Its technical simplicity, the high-throughput format and the good predictivity may make this assay a candidate for rapid validation to meet the tight deadline to replace animal tests for skin sensitization by 2013 set by the European authorities.

  6. Wavenumber selection based analysis in Raman spectroscopy improves skin cancer diagnostic specificity at high sensitivity levels (Conference Presentation)

    Science.gov (United States)

    Zhao, Jianhua; Zeng, Haishan; Kalia, Sunil; Lui, Harvey

    2017-02-01

    Background: Raman spectroscopy is a non-invasive optical technique which can measure molecular vibrational modes within tissue. A large-scale clinical study (n = 518) has demonstrated that real-time Raman spectroscopy could distinguish malignant from benign skin lesions with good diagnostic accuracy; this was validated by a follow-up independent study (n = 127). Objective: Most of the previous diagnostic algorithms have typically been based on analyzing the full band of the Raman spectra, either in the fingerprint or high wavenumber regions. Our objective in this presentation is to explore wavenumber selection based analysis in Raman spectroscopy for skin cancer diagnosis. Methods: A wavenumber selection algorithm was implemented using variably-sized wavenumber windows, which were determined by the correlation coefficient between wavenumbers. Wavenumber windows were chosen based on accumulated frequency from leave-one-out cross-validated stepwise regression or least and shrinkage selection operator (LASSO). The diagnostic algorithms were then generated from the selected wavenumber windows using multivariate statistical analyses, including principal component and general discriminant analysis (PC-GDA) and partial least squares (PLS). A total cohort of 645 confirmed lesions from 573 patients encompassing skin cancers, precancers and benign skin lesions were included. Lesion measurements were divided into training cohort (n = 518) and testing cohort (n = 127) according to the measurement time. Result: The area under the receiver operating characteristic curve (ROC) improved from 0.861-0.891 to 0.891-0.911 and the diagnostic specificity for sensitivity levels of 0.99-0.90 increased respectively from 0.17-0.65 to 0.20-0.75 by selecting specific wavenumber windows for analysis. Conclusion: Wavenumber selection based analysis in Raman spectroscopy improves skin cancer diagnostic specificity at high sensitivity levels.

  7. Is skin penetration a determining factor in skin sensitization ...

    Science.gov (United States)

    Summary:Background. It is widely accepted that substances that cannot penetrate through the skin will not be sensitisers. Thresholds based on relevant physicochemical parameters such as a LogKow > 1 and a MW 1 is a true requirement for sensitisation.Methods. A large dataset of substances that had been evaluated for their skin sensitisation potential, together with measured LogKow values was compiled from the REACH database. The incidence of skin sensitisers relative to non-skin sensitisers below and above the LogKow = 1 threshold was evaluated. Results. 1482 substances with associated skin sensitisation outcomes and measured LogKow values were identified. 305 substances had a measured LogKow self-evident truth borne out from the widespread misconception that the ability to efficiently penetrate the stratum corneum is a key determinant of skin sensitisation potential and potency. Using the REACH data extracted to test out the validity of common assumptions in the skin sensitization AOP. Builds on trying to develop a proof of concept IATA

  8. High sensitivity optical measurement of skin gloss

    NARCIS (Netherlands)

    Ezerskaia, A.; Ras, Arno; Bloemen, Pascal; Pereira, S.F.; Urbach, Paul; Varghese, Babu

    2017-01-01

    We demonstrate a low-cost optical method for measuring the gloss properties with improved sensitivity in the low gloss regime, relevant for skin gloss properties. The gloss estimation method is based on, on the one hand, the slope of the intensity gradient in the transition regime between

  9. A genomic biomarker signature can predict skin sensitizers using a cell-based in vitro alternative to animal tests

    Directory of Open Access Journals (Sweden)

    Albrekt Ann-Sofie

    2011-08-01

    Full Text Available Abstract Background Allergic contact dermatitis is an inflammatory skin disease that affects a significant proportion of the population. This disease is caused by an adverse immune response towards chemical haptens, and leads to a substantial economic burden for society. Current test of sensitizing chemicals rely on animal experimentation. New legislations on the registration and use of chemicals within pharmaceutical and cosmetic industries have stimulated significant research efforts to develop alternative, human cell-based assays for the prediction of sensitization. The aim is to replace animal experiments with in vitro tests displaying a higher predictive power. Results We have developed a novel cell-based assay for the prediction of sensitizing chemicals. By analyzing the transcriptome of the human cell line MUTZ-3 after 24 h stimulation, using 20 different sensitizing chemicals, 20 non-sensitizing chemicals and vehicle controls, we have identified a biomarker signature of 200 genes with potent discriminatory ability. Using a Support Vector Machine for supervised classification, the prediction performance of the assay revealed an area under the ROC curve of 0.98. In addition, categorizing the chemicals according to the LLNA assay, this gene signature could also predict sensitizing potency. The identified markers are involved in biological pathways with immunological relevant functions, which can shed light on the process of human sensitization. Conclusions A gene signature predicting sensitization, using a human cell line in vitro, has been identified. This simple and robust cell-based assay has the potential to completely replace or drastically reduce the utilization of test systems based on experimental animals. Being based on human biology, the assay is proposed to be more accurate for predicting sensitization in humans, than the traditional animal-based tests.

  10. A genomic biomarker signature can predict skin sensitizers using a cell-based in vitro alternative to animal tests

    Science.gov (United States)

    2011-01-01

    Background Allergic contact dermatitis is an inflammatory skin disease that affects a significant proportion of the population. This disease is caused by an adverse immune response towards chemical haptens, and leads to a substantial economic burden for society. Current test of sensitizing chemicals rely on animal experimentation. New legislations on the registration and use of chemicals within pharmaceutical and cosmetic industries have stimulated significant research efforts to develop alternative, human cell-based assays for the prediction of sensitization. The aim is to replace animal experiments with in vitro tests displaying a higher predictive power. Results We have developed a novel cell-based assay for the prediction of sensitizing chemicals. By analyzing the transcriptome of the human cell line MUTZ-3 after 24 h stimulation, using 20 different sensitizing chemicals, 20 non-sensitizing chemicals and vehicle controls, we have identified a biomarker signature of 200 genes with potent discriminatory ability. Using a Support Vector Machine for supervised classification, the prediction performance of the assay revealed an area under the ROC curve of 0.98. In addition, categorizing the chemicals according to the LLNA assay, this gene signature could also predict sensitizing potency. The identified markers are involved in biological pathways with immunological relevant functions, which can shed light on the process of human sensitization. Conclusions A gene signature predicting sensitization, using a human cell line in vitro, has been identified. This simple and robust cell-based assay has the potential to completely replace or drastically reduce the utilization of test systems based on experimental animals. Being based on human biology, the assay is proposed to be more accurate for predicting sensitization in humans, than the traditional animal-based tests. PMID:21824406

  11. High sensitivity optical measurement of skin gloss.

    Science.gov (United States)

    Ezerskaia, Anna; Ras, Arno; Bloemen, Pascal; Pereira, Silvania F; Urbach, H Paul; Varghese, Babu

    2017-09-01

    We demonstrate a low-cost optical method for measuring the gloss properties with improved sensitivity in the low gloss regime, relevant for skin gloss properties. The gloss estimation method is based on, on the one hand, the slope of the intensity gradient in the transition regime between specular and diffuse reflection and on the other on the sum over the intensities of pixels above threshold, derived from a camera image obtained using unpolarized white light illumination. We demonstrate the improved sensitivity of the two proposed methods using Monte Carlo simulations and experiments performed on ISO gloss calibration standards with an optical prototype. The performance and linearity of the method was compared with different professional gloss measurement devices based on the ratio of specular to diffuse intensity. We demonstrate the feasibility for in-vivo skin gloss measurements by quantifying the temporal evolution of skin gloss after application of standard paraffin cream bases on skin. The presented method opens new possibilities in the fields of cosmetology and dermatopharmacology for measuring the skin gloss and resorption kinetics and the pharmacodynamics of various external agents.

  12. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    International Nuclear Information System (INIS)

    Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2015-01-01

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R 2 = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q 2 ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin sensitization and

  13. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Vinicius M. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Muratov, Eugene [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Laboratory of Theoretical Chemistry, A.V. Bogatsky Physical–Chemical Institute NAS of Ukraine, Odessa 65080 (Ukraine); Fourches, Denis [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Strickland, Judy; Kleinstreuer, Nicole [ILS/Contractor supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), P.O. Box 13501, Research Triangle Park, NC 27709 (United States); Andrade, Carolina H. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States)

    2015-04-15

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R{sup 2} = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q{sup 2}{sub ext} = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin

  14. High sensitivity optical measurement of skin gloss

    OpenAIRE

    Ezerskaia, Anna; Ras, Arno; Bloemen, Pascal; Pereira, Silvania F.; Urbach, H. Paul; Varghese, Babu

    2017-01-01

    We demonstrate a low-cost optical method for measuring the gloss properties with improved sensitivity in the low gloss regime, relevant for skin gloss properties. The gloss estimation method is based on, on the one hand, the slope of the intensity gradient in the transition regime between specular and diffuse reflection and on the other on the sum over the intensities of pixels above threshold, derived from a camera image obtained using unpolarized white light illumination. We demonstrate the...

  15. An in vitro human skin test for assessing sensitization potential.

    Science.gov (United States)

    Ahmed, S S; Wang, X N; Fielding, M; Kerry, A; Dickinson, I; Munuswamy, R; Kimber, I; Dickinson, A M

    2016-05-01

    Sensitization to chemicals resulting in an allergy is an important health issue. The current gold-standard method for identification and characterization of skin-sensitizing chemicals was the mouse local lymph node assay (LLNA). However, for a number of reasons there has been an increasing imperative to develop alternative approaches to hazard identification that do not require the use of animals. Here we describe a human in-vitro skin explant test for identification of sensitization hazards and the assessment of relative skin sensitizing potency. This method measures histological damage in human skin as a readout of the immune response induced by the test material. Using this approach we have measured responses to 44 chemicals including skin sensitizers, pre/pro-haptens, respiratory sensitizers, non-sensitizing chemicals (including skin-irritants) and previously misclassified compounds. Based on comparisons with the LLNA, the skin explant test gave 95% specificity, 95% sensitivity, 95% concordance with a correlation coefficient of 0.9. The same specificity and sensitivity were achieved for comparison of results with published human sensitization data with a correlation coefficient of 0.91. The test also successfully identified nickel sulphate as a human skin sensitizer, which was misclassified as negative in the LLNA. In addition, sensitizers and non-sensitizers identified as positive or negative by the skin explant test have induced high/low T cell proliferation and IFNγ production, respectively. Collectively, the data suggests the human in-vitro skin explant test could provide the basis for a novel approach for characterization of the sensitizing activity as a first step in the risk assessment process. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Sensitization to Food Additives in Patients with Allergy: A Study Based on Skin Test and Open Oral Challenge.

    Science.gov (United States)

    Moghtaderi, Mozhgan; Hejrati, Zinatosadat; Dehghani, Zahra; Dehghani, Faranak; Kolahi, Niloofar

    2016-06-01

    There has been a great increase in the consumption of various food additives in recent years. The purpose of this study was to identify the incidence of sensitization to food additives by using skin prick test in patients with allergy and to determine the concordance rate between positive skin tests and oral challenge in hypersensitivity to additives. This cross-sectional study included 125 (female 71, male 54) patients aged 2-76 years with allergy and 100 healthy individuals. Skin tests were performed in both patient and control groups with 25 fresh food additives. Among patients with allergy, 22.4% showed positive skin test at least to one of the applied materials. Skin test was negative to all tested food additives in control group. Oral food challenge was done in 28 patients with positive skin test, in whom 9 patients showed reaction to culprit (Concordance rate=32.1%). The present study suggested that about one-third of allergic patients with positive reaction to food additives showed positive oral challenge; it may be considered the potential utility of skin test to identify the role of food additives in patients with allergy.

  17. Probabilistic derivation of the interspecies assessment factor for skin sensitization.

    NARCIS (Netherlands)

    Bil, W; Schuur, A G; Ezendam, J; Bokkers, B G H

    An interspecies sensitization assessment factor (SAF) is used in the quantitative risk assessment (QRA) for skin sensitization when a murine-based NESIL (No Expected Sensitization Induction Level) is taken as point of departure. Several studies showed that, on average, the murine sensitization

  18. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    Science.gov (United States)

    Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2015-01-01

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R2=0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q2ext = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. PMID:25560673

  19. Electrocutaneous sensitivity: effects of skin temperature.

    Science.gov (United States)

    Larkin, W D; Reilly, J P

    1986-01-01

    The effect of human skin temperature on electrocutaneous sensitivity was examined using brief capacitive discharges. Stimuli were designed to ensure that sensory effects would be independent of skin resistance and would reflect underlying neural excitability as closely as possible. Skin temperature was manipulated by immersing the forearm in circulating hot or cold air. Detection thresholds on the arm and fingertip were raised by cooling, but were not altered by heating. Temperature-related sensitivity shifts were described by the same multiplicative factors for both threshold and suprathreshold levels. The temperature coefficient (Q10) for cutaneous sensitivity under these conditions was approximately 1.3.

  20. Multivariate Models for Prediction of Human Skin Sensitization ...

    Science.gov (United States)

    One of the lnteragency Coordinating Committee on the Validation of Alternative Method's (ICCVAM) top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary to produce skin sensitization suggests that no single alternative method will replace the currently accepted animal tests. ICCVAM is evaluating an integrated approach to testing and assessment based on the adverse outcome pathway for skin sensitization that uses machine learning approaches to predict human skin sensitization hazard. We combined data from three in chemico or in vitro assays - the direct peptide reactivity assay (DPRA), human cell line activation test (h-CLAT) and KeratinoSens TM assay - six physicochemical properties and an in silico read-across prediction of skin sensitization hazard into 12 variable groups. The variable groups were evaluated using two machine learning approaches , logistic regression and support vector machine, to predict human skin sensitization hazard. Models were trained on 72 substances and tested on an external set of 24 substances. The six models (three logistic regression and three support vector machine) with the highest accuracy (92%) used: (1) DPRA, h-CLAT and read-across; (2) DPRA, h-CLAT, read-across and KeratinoSens; or (3) DPRA, h-CLAT, read-across, KeratinoSens and log P. The models performed better at predicting human skin sensitization hazard than the murine

  1. 4D-Fingerprint Categorical QSAR Models for Skin Sensitization Based on Classification Local Lymph Node Assay Measures

    Science.gov (United States)

    Li, Yi; Tseng, Yufeng J.; Pan, Dahua; Liu, Jianzhong; Kern, Petra S.; Gerberick, G. Frank; Hopfinger, Anton J.

    2008-01-01

    Currently, the only validated methods to identify skin sensitization effects are in vivo models, such as the Local Lymph Node Assay (LLNA) and guinea pig studies. There is a tremendous need, in particular due to novel legislation, to develop animal alternatives, eg. Quantitative Structure-Activity Relationship (QSAR) models. Here, QSAR models for skin sensitization using LLNA data have been constructed. The descriptors used to generate these models are derived from the 4D-molecular similarity paradigm and are referred to as universal 4D-fingerprints. A training set of 132 structurally diverse compounds and a test set of 15 structurally diverse compounds were used in this study. The statistical methodologies used to build the models are logistic regression (LR), and partial least square coupled logistic regression (PLS-LR), which prove to be effective tools for studying skin sensitization measures expressed in the two categorical terms of sensitizer and non-sensitizer. QSAR models with low values of the Hosmer-Lemeshow goodness-of-fit statistic, χHL2, are significant and predictive. For the training set, the cross-validated prediction accuracy of the logistic regression models ranges from 77.3% to 78.0%, while that of PLS-logistic regression models ranges from 87.1% to 89.4%. For the test set, the prediction accuracy of logistic regression models ranges from 80.0%-86.7%, while that of PLS-logistic regression models ranges from 73.3%-80.0%. The QSAR models are made up of 4D-fingerprints related to aromatic atoms, hydrogen bond acceptors and negatively partially charged atoms. PMID:17226934

  2. Pred-Skin: A Fast and Reliable Web Application to Assess Skin Sensitization Effect of Chemicals.

    Science.gov (United States)

    Braga, Rodolpho C; Alves, Vinicius M; Muratov, Eugene N; Strickland, Judy; Kleinstreuer, Nicole; Trospsha, Alexander; Andrade, Carolina Horta

    2017-05-22

    Chemically induced skin sensitization is a complex immunological disease with a profound impact on quality of life and working ability. Despite some progress in developing alternative methods for assessing the skin sensitization potential of chemical substances, there is no in vitro test that correlates well with human data. Computational QSAR models provide a rapid screening approach and contribute valuable information for the assessment of chemical toxicity. We describe the development of a freely accessible web-based and mobile application for the identification of potential skin sensitizers. The application is based on previously developed binary QSAR models of skin sensitization potential from human (109 compounds) and murine local lymph node assay (LLNA, 515 compounds) data with good external correct classification rate (0.70-0.81 and 0.72-0.84, respectively). We also included a multiclass skin sensitization potency model based on LLNA data (accuracy ranging between 0.73 and 0.76). When a user evaluates a compound in the web app, the outputs are (i) binary predictions of human and murine skin sensitization potential; (ii) multiclass prediction of murine skin sensitization; and (iii) probability maps illustrating the predicted contribution of chemical fragments. The app is the first tool available that incorporates quantitative structure-activity relationship (QSAR) models based on human data as well as multiclass models for LLNA. The Pred-Skin web app version 1.0 is freely available for the web, iOS, and Android (in development) at the LabMol web portal ( http://labmol.com.br/predskin/ ), in the Apple Store, and on Google Play, respectively. We will continuously update the app as new skin sensitization data and respective models become available.

  3. Safety Evaluation of Cosmetic Ingredients Regarding Their Skin Sensitization Potential

    Directory of Open Access Journals (Sweden)

    Winfried Steiling

    2016-03-01

    Full Text Available Up to today, product safety evaluation in the EU is predominantly based on data/information on their individual ingredients. Consequently, the quality and reliability of individual ingredient data is of vital interest. In this context, the knowledge about skin sensitization potential is an explicit need for both hazard and risk assessment. Proper skin sensitization data of the individual chemicals is essential, especially when dermal contact is intended, like for cosmetics. In some cases, e.g., in the presence of irritating chemicals, the combination of individual ingredients may also need to be evaluated to cover possible mixture effects. Today, it seems unlikely or even impossible that skin sensitization in humans can be adequately described by a single test result or even by a simple combination of a few data points (in vivo or in vitro. It is becoming evident that a set of data (including human data and market data and knowledge about the ingredient’s specific sensitizing potency needs to be taken into account to enable a reliable assessment of skin sensitization. A more in-depth understanding on mechanistic details of the Adverse-Outcome-Pathway of skin sensitization could contribute key data for a robust conclusion on skin sensitization.

  4. CADRE-SS, an in Silico Tool for Predicting Skin Sensitization Potential Based on Modeling of Molecular Interactions.

    Science.gov (United States)

    Kostal, Jakub; Voutchkova-Kostal, Adelina

    2016-01-19

    Using computer models to accurately predict toxicity outcomes is considered to be a major challenge. However, state-of-the-art computational chemistry techniques can now be incorporated in predictive models, supported by advances in mechanistic toxicology and the exponential growth of computing resources witnessed over the past decade. The CADRE (Computer-Aided Discovery and REdesign) platform relies on quantum-mechanical modeling of molecular interactions that represent key biochemical triggers in toxicity pathways. Here, we present an external validation exercise for CADRE-SS, a variant developed to predict the skin sensitization potential of commercial chemicals. CADRE-SS is a hybrid model that evaluates skin permeability using Monte Carlo simulations, assigns reactive centers in a molecule and possible biotransformations via expert rules, and determines reactivity with skin proteins via quantum-mechanical modeling. The results were promising with an overall very good concordance of 93% between experimental and predicted values. Comparison to performance metrics yielded by other tools available for this endpoint suggests that CADRE-SS offers distinct advantages for first-round screenings of chemicals and could be used as an in silico alternative to animal tests where permissible by legislative programs.

  5. Multivariate Models for Prediction of Human Skin Sensitization Hazard

    Science.gov (United States)

    Strickland, Judy; Zang, Qingda; Paris, Michael; Lehmann, David M.; Allen, David; Choksi, Neepa; Matheson, Joanna; Jacobs, Abigail; Casey, Warren; Kleinstreuer, Nicole

    2016-01-01

    One of ICCVAM’s top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary to produce skin sensitization suggests that no single alternative method will replace the currently accepted animal tests. ICCVAM is evaluating an integrated approach to testing and assessment based on the adverse outcome pathway for skin sensitization that uses machine learning approaches to predict human skin sensitization hazard. We combined data from three in chemico or in vitro assays—the direct peptide reactivity assay (DPRA), human cell line activation test (h-CLAT), and KeratinoSens™ assay—six physicochemical properties, and an in silico read-across prediction of skin sensitization hazard into 12 variable groups. The variable groups were evaluated using two machine learning approaches, logistic regression (LR) and support vector machine (SVM), to predict human skin sensitization hazard. Models were trained on 72 substances and tested on an external set of 24 substances. The six models (three LR and three SVM) with the highest accuracy (92%) used: (1) DPRA, h-CLAT, and read-across; (2) DPRA, h-CLAT, read-across, and KeratinoSens; or (3) DPRA, h-CLAT, read-across, KeratinoSens, and log P. The models performed better at predicting human skin sensitization hazard than the murine local lymph node assay (accuracy = 88%), any of the alternative methods alone (accuracy = 63–79%), or test batteries combining data from the individual methods (accuracy = 75%). These results suggest that computational methods are promising tools to effectively identify potential human skin sensitizers without animal testing. PMID:27480324

  6. The local lymph node assay and skin sensitization testing.

    Science.gov (United States)

    Kimber, Ian; Dearman, Rebecca J

    2010-01-01

    The mouse local lymph node assay (LLNA) is a method for the identification and characterization of skin sensitization hazards. In this context the method can be used both to identify contact allergens, and also determine the relative skin sensitizing potency as a basis for derivation of effective risk assessments.The assay is based on measurement of proliferative responses by draining lymph node cells induced following topical exposure of mice to test chemicals. Such responses are known to be causally and quantitatively associated with the acquisition of skin sensitization and therefore provide a relevant marker for characterization of contact allergic potential.The LLNA has been the subject of exhaustive evaluation and validation exercises and has been assigned Organization for Economic Cooperation and Development (OECD) test guideline 429. Herein we describe the conduct and interpretation of the LLNA.

  7. Skin acceptability of a cosmetic moisturizer formulation in female subjects with sensitive skin

    Directory of Open Access Journals (Sweden)

    Nisbet SJ

    2018-04-01

    Full Text Available Stephanie J Nisbet Skin Health Medical Affairs, GSK Consumer Healthcare, Weybridge, Surrey, UK Purpose: This 3-week, open-label, noncomparative clinical study evaluated the skin acceptability of a cosmetic moisturizer in subjects with sensitive skin, by monitoring adverse events (AEs and cutaneous discomfort related to normal usage.Materials and methods: Female subjects aged between 18–60 years, with Fitzpatrick phototype classification I–IV and sensitive skin, verified by a positive reaction on the stinging test at screening, were included. Subjects applied the moisturizer to their face and body twice daily for 21±2 days at home and recorded study product usage and feelings of cutaneous discomfort (eg, dryness, prickling, stinging, and itching in a diary; any AEs were reported to the clinic. At study end, skin acceptability of the moisturizer was investigator-assessed based on the nature of AEs and subjects’ self-reported feelings of discomfort, and by clinical evaluation of skin reactions in the area of moisturizer application (appearance of erythema, formation of edema, and skin desquamation; scored according to an adapted Draize and Kligman scale. Only subjects with a treatment compliance of ≥80% were included in the final analysis.Results: In total, 35 subjects initiated and completed the study; all were compliant to the minimum study product usage. Per investigator clinical dermatological assessment at study end, none of the 35 subjects had skin reactions in the area of moisturizer application and there were no reported AEs. One subject reported sensations of mild prickling and itching immediately after applying the moisturizer (not classified as AEs, which spontaneously remitted after complete absorption of the product and were noted only in exposed areas. These events were considered by the investigator as being possibly/probably related to the use of study product; however, no clinical signs of skin reaction were observed in

  8. Categorical QSAR models for skin sensitization based on local lymph node assay measures and both ground and excited state 4D-fingerprint descriptors

    Science.gov (United States)

    Liu, Jianzhong; Kern, Petra S.; Gerberick, G. Frank; Santos-Filho, Osvaldo A.; Esposito, Emilio X.; Hopfinger, Anton J.; Tseng, Yufeng J.

    2008-06-01

    In previous studies we have developed categorical QSAR models for predicting skin-sensitization potency based on 4D-fingerprint (4D-FP) descriptors and in vivo murine local lymph node assay (LLNA) measures. Only 4D-FP derived from the ground state (GMAX) structures of the molecules were used to build the QSAR models. In this study we have generated 4D-FP descriptors from the first excited state (EMAX) structures of the molecules. The GMAX, EMAX and the combined ground and excited state 4D-FP descriptors (GEMAX) were employed in building categorical QSAR models. Logistic regression (LR) and partial least square coupled logistic regression (PLS-CLR), found to be effective model building for the LLNA skin-sensitization measures in our previous studies, were used again in this study. This also permitted comparison of the prior ground state models to those involving first excited state 4D-FP descriptors. Three types of categorical QSAR models were constructed for each of the GMAX, EMAX and GEMAX datasets: a binary model (2-state), an ordinal model (3-state) and a binary-binary model (two-2-state). No significant differences exist among the LR 2-state model constructed for each of the three datasets. However, the PLS-CLR 3-state and 2-state models based on the EMAX and GEMAX datasets have higher predictivity than those constructed using only the GMAX dataset. These EMAX and GMAX categorical models are also more significant and predictive than corresponding models built in our previous QSAR studies of LLNA skin-sensitization measures.

  9. Multivariate Models for Prediction of Human Skin Sensitization Hazard.

    Science.gov (United States)

    One of the lnteragency Coordinating Committee on the Validation of Alternative Method's (ICCVAM) top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary to produce skin sensiti...

  10. Decreased active vasodilator sensitivity in aged skin.

    Science.gov (United States)

    Kenney, W L; Morgan, A L; Farquhar, W B; Brooks, E M; Pierzga, J M; Derr, J A

    1997-04-01

    Older men and women respond to local and reflex-mediated heat stress with an attenuated increase in cutaneous vascular conductance (CVC). This study was performed to test the hypothesis that an augmented or sustained noradrenergic vasoconstriction (VC) may play a role in this age-related difference. Fifteen young (22 +/- 1 yr) and 15 older (66 +/- 1 yr) men exercised at 50% peak oxygen uptake in a 36 degrees C environment. Skin perfusion was monitored at two sites on the right forearm by laser-Doppler flowmetry: one site pretreated with bretylium tosylate (BT) to block the local release of norepinephrine and thus VC and an adjacent control site. Blockade of reflex VC was verified during whole body cooling using a water-perfused suit. CVC (perfusion divided by mean arterial pressure) at each site was reported as a percentage of the maximal CVC (%CVCmax) induced at the end of each experiment by prolonged local heating at 42 degrees C. Neither age nor BT affected the %CVCmax (75-86%) attained at high core temperatures. During the early rise phase of CVC, the %CVCmax-change in esophageal temperature (delta T(es)) curve was shifted to the right in the older men (effective delta T(es) associated with 50% CVC response for young, 0.22 +/- 0.04 and 0.39 +/- 0.04 degrees C and for older, 0.73 +/- 0.04 and 0.85 +/- 0.04 degrees C at control and BT sites, respectively). BT had no interactive effect on this age difference, suggesting a lack of involvement of the VC system in the attenuated CVC response of individuals over the age of 60 yr. Additionally, increases in skin vascular conductance were quantitatively compared by measuring increases in total forearm vascular conductance (FVC, restricted to the forearm skin under these conditions). After the initial approximately 0.2 degrees C increase in T(es), FVC was 40-50% lower in the older men (P < 0.01) for the remainder of the exercise. Decreased active vasodilator sensitivity to increasing core temperature, coupled with

  11. Prediction of Skin Sensitization Potency Using Machine Learning Approaches

    Science.gov (United States)

    Replacing animal tests currently used for regulatory hazard classification of skin sensitizers is one of ICCVAM’s top priorities. Accordingly, U.S. federal agency scientists are developing and evaluating computational approaches to classify substances as sensitizers or nons...

  12. Dermal safety assessment of Arm & Hammer laundry products formulated for sensitive skin.

    Science.gov (United States)

    Frederick, Douglas M; Vorwerk, Linda; Gupta, Archana; Ghassemi, Annahita

    2017-09-01

    The prevalence of sensitive skin among the general population in industrialized countries is reported to be over 50%. Sensitive skin subjects often report significant reactions to contact with cosmetics, soaps and other consumer products. This paper describes the overall skin compatibility and mildness program for a newly developed, lightly fragranced, colorant free laundry product (i.e. Arm & Hammer™ Sensitive Skin plus Skin-Friendly Fresh Scent), specially formulated for individuals with sensitive skin. The skin mildness of the product was compared to Arm & Hammer™ Free & Clear liquid laundry detergent with no fragrance or colorant, and an established history of safe use by sensitive skin consumers. The test material was a liquid laundry product with a light scent formulated for sensitive skin consumers (Arm & Hammer™ Sensitive Skin plus Skin-Friendly Fresh Scent). The product was compared to commercially marketed products for sensitive skin with a history of skin safety in the marketplace, including: a very similar product formulation (Arm & Hammer™ Free & Clear with no fragrance), and several selected competitors' products. Studies were conducted among individuals with self-assessed sensitive skin (based on a questionnaire) using standard protocols for the Human Repeat Insult Patch Test (HRIPT), 10-Day Cumulative Irritation, the Wrist Band Wear test, and the Safety In-Use testing. Responses in all protocols were evaluated by visual scoring of potential dermatologic reactions, and recording any sensory effects at the time of the examination. In addition, sensory effects collected from panelists' daily diaries were also evaluated. The HRIPT confirmed that neither the fragrance alone, nor the product formulation with fragrance, induced contact sensitization in sensitive skin subjects. The 10-Day cumulative irritation study conducted using sensitive skin subjects showed highly favorable skin compatibility, and the test product was comparable to the control

  13. Machine Learning Approaches for Predicting Human Skin Sensitization Hazard

    Science.gov (United States)

    One of ICCVAM’s top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary for a substance to elicit a skin sensitization reaction suggests that no single in chemico, in vit...

  14. Multivariate Models for Prediction of Skin Sensitization Hazard in Humans

    Science.gov (United States)

    One of ICCVAM’s highest priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary for a substance to elicit a skin sensitization reaction suggests that no single alternative me...

  15. Determinants of skin sensitivity to solar irradiation

    NARCIS (Netherlands)

    Broekmans, W.; Vink, A.A.; Boelsma, E.; Klöpping-Ketelaars, W.A.A.; Tijburg, L.B.M.; Veer, van 't P.; Poppel, van G.; Kardinaal, A.F.M.

    2003-01-01

    Background: Acute effects of UV irradiation include UV-induced erythema. Sunlight plays an important role in the development of skin cancer. Several predictive factors of UV-induced erythema could also be predictive for skin cancer. Objective: Our objective was to quantitatively assess phenotypical

  16. Sensitivity of Satellite-Based Skin Temperature to Different Surface Emissivity and NWP Reanalysis Sources Demonstrated Using a Single-Channel, Viewing-Angle-Corrected Retrieval Algorithm

    Science.gov (United States)

    Scarino, B. R.; Minnis, P.; Yost, C. R.; Chee, T.; Palikonda, R.

    2015-12-01

    Single-channel algorithms for satellite thermal-infrared- (TIR-) derived land and sea surface skin temperature (LST and SST) are advantageous in that they can be easily applied to a variety of satellite sensors. They can also accommodate decade-spanning instrument series, particularly for periods when split-window capabilities are not available. However, the benefit of one unified retrieval methodology for all sensors comes at the cost of critical sensitivity to surface emissivity (ɛs) and atmospheric transmittance estimation. It has been demonstrated that as little as 0.01 variance in ɛs can amount to more than a 0.5-K adjustment in retrieved LST values. Atmospheric transmittance requires calculations that employ vertical profiles of temperature and humidity from numerical weather prediction (NWP) models. Selection of a given NWP model can significantly affect LST and SST agreement relative to their respective validation sources. Thus, it is necessary to understand the accuracies of the retrievals for various NWP models to ensure the best LST/SST retrievals. The sensitivities of the single-channel retrievals to surface emittance and NWP profiles are investigated using NASA Langley historic land and ocean clear-sky skin temperature (Ts) values derived from high-resolution 11-μm TIR brightness temperature measured from geostationary satellites (GEOSat) and Advanced Very High Resolution Radiometers (AVHRR). It is shown that mean GEOSat-derived, anisotropy-corrected LST can vary by up to ±0.8 K depending on whether CERES or MODIS ɛs sources are used. Furthermore, the use of either NOAA Global Forecast System (GFS) or NASA Goddard Modern-Era Retrospective Analysis for Research and Applications (MERRA) for the radiative transfer model initial atmospheric state can account for more than 0.5-K variation in mean Ts. The results are compared to measurements from the Surface Radiation Budget Network (SURFRAD), an Atmospheric Radiation Measurement (ARM) Program ground

  17. Skin care products can aggravate epidermal function: studies in a murine model suggest a pathogenic role in sensitive skin

    OpenAIRE

    Li, Z; Hu, L; Elias, PM; Man, M-Q

    2018-01-01

    Sensitive skin is defined as a spectrum of unpleasant sensations in response to a variety of stimuli. However, only some skin care products provoke cutaneous symptoms in individuals with sensitive skin. Hence, it would be useful to identify products that could provoke cutaneous symptoms in individuals with sensitive skin.To assess whether vehicles, as well as certain branded skin care products, can alter epidermal function following topical applications to normal mouse skin.Following topical ...

  18. The choice of sensitive skin layer responsible for aftereffects of daily irradiation of the skin

    International Nuclear Information System (INIS)

    Keirim-Markus, I.B.

    1992-01-01

    The choice of sensitive human skin layer manifesting in delayed period after daily irradiation of the human skin (stochastic and determined effects) was evaluated. It was established that delayed aftereffects of daily radiation of the skin manifested as epidem damages. This layer of papilla derma of 10-15 mg/cm 2 thick situated at the great part of body surface, 15 mg/cm 2 on dorsal side of hands and 40 mg/cm 2 on palms and pillows of the fingers. Sensitive layer of skin dosimeter for a control of daily irradiation of people must have the same geometry

  19. Estimating skin sensitization potency from a single dose LLNA.

    Science.gov (United States)

    Roberts, David W

    2015-04-01

    Skin sensitization is an important aspect of safety assessment. The mouse local lymph node assay (LLNA) developed in the 1990 s is an in vivo test used for skin sensitization hazard identification and characterization. More recently a reduced version of the LLNA (rLLNA) has been developed as a means of identifying, but not quantifying, sensitization hazard. The work presented here is aimed at enabling rLLNA data to be used to give quantitative potency information that can be used, inter alia, in modeling and read-across approaches to non-animal based potency estimation. A probit function has been derived enabling estimation of EC3 from a single dose. This has led to development of a modified version of the rLLNA, whereby as a general principle the SI value at 10%, or at a lower concentration if 10% is not testable, is used to calculate the EC3. This version of the rLLNA has been evaluated against a selection of chemicals for which full LLNA data are available, and has been shown to give EC3 values in good agreement with those derived from the full LLNA. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. IATA-Bayesian Network Model for Skin Sensitization Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Since the publication of the Adverse Outcome Pathway (AOP) for skin sensitization, there have been many efforts to develop systematic approaches to integrate the...

  1. WE-DE-201-11: Sensitivity and Specificity of Verification Methods Based On Total Reference Air Kerma (TRAK) Or On User Provided Dose Points for Graphically Planned Skin HDR Brachytherapy

    International Nuclear Information System (INIS)

    Damato, A; Devlin, P; Bhagwat, M; Buzurovic, I; Hansen, J; O’Farrell, D; Cormack, R

    2016-01-01

    Purpose: To investigate the sensitivity and specificity of a novel verification methodology for image-guided skin HDR brachytherapy plans using a TRAK-based reasonableness test, compared to a typical manual verification methodology. Methods: Two methodologies were used to flag treatment plans necessitating additional review due to a potential discrepancy of 3 mm between planned dose and clinical target in the skin. Manual verification was used to calculate the discrepancy between the average dose to points positioned at time of planning representative of the prescribed depth and the expected prescription dose. Automatic verification was used to calculate the discrepancy between TRAK of the clinical plan and its expected value, which was calculated using standard plans with varying curvatures, ranging from flat to cylindrically circumferential. A plan was flagged if a discrepancy >10% was observed. Sensitivity and specificity were calculated using as a criteria for true positive that >10% of plan dwells had a distance to prescription dose >1 mm different than prescription depth (3 mm + size of applicator). All HDR image-based skin brachytherapy plans treated at our institution in 2013 were analyzed. Results: 108 surface applicator plans to treat skin of the face, scalp, limbs, feet, hands or abdomen were analyzed. Median number of catheters was 19 (range, 4 to 71) and median number of dwells was 257 (range, 20 to 1100). Sensitivity/specificity were 57%/78% for manual and 70%/89% for automatic verification. Conclusion: A check based on expected TRAK value is feasible for irregularly shaped, image-guided skin HDR brachytherapy. This test yielded higher sensitivity and specificity than a test based on the identification of representative points, and can be implemented with a dedicated calculation code or with pre-calculated lookup tables of ideally shaped, uniform surface applicators.

  2. WE-DE-201-11: Sensitivity and Specificity of Verification Methods Based On Total Reference Air Kerma (TRAK) Or On User Provided Dose Points for Graphically Planned Skin HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Damato, A; Devlin, P; Bhagwat, M; Buzurovic, I; Hansen, J; O’Farrell, D; Cormack, R [Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: To investigate the sensitivity and specificity of a novel verification methodology for image-guided skin HDR brachytherapy plans using a TRAK-based reasonableness test, compared to a typical manual verification methodology. Methods: Two methodologies were used to flag treatment plans necessitating additional review due to a potential discrepancy of 3 mm between planned dose and clinical target in the skin. Manual verification was used to calculate the discrepancy between the average dose to points positioned at time of planning representative of the prescribed depth and the expected prescription dose. Automatic verification was used to calculate the discrepancy between TRAK of the clinical plan and its expected value, which was calculated using standard plans with varying curvatures, ranging from flat to cylindrically circumferential. A plan was flagged if a discrepancy >10% was observed. Sensitivity and specificity were calculated using as a criteria for true positive that >10% of plan dwells had a distance to prescription dose >1 mm different than prescription depth (3 mm + size of applicator). All HDR image-based skin brachytherapy plans treated at our institution in 2013 were analyzed. Results: 108 surface applicator plans to treat skin of the face, scalp, limbs, feet, hands or abdomen were analyzed. Median number of catheters was 19 (range, 4 to 71) and median number of dwells was 257 (range, 20 to 1100). Sensitivity/specificity were 57%/78% for manual and 70%/89% for automatic verification. Conclusion: A check based on expected TRAK value is feasible for irregularly shaped, image-guided skin HDR brachytherapy. This test yielded higher sensitivity and specificity than a test based on the identification of representative points, and can be implemented with a dedicated calculation code or with pre-calculated lookup tables of ideally shaped, uniform surface applicators.

  3. Physicochemical properties of pH-sensitive hydrogels based on hydroxyethyl cellulose-hyaluronic acid and for applications as transdermal delivery systems for skin lesions.

    Science.gov (United States)

    Kwon, Soon Sik; Kong, Bong Ju; Park, Soo Nam

    2015-05-01

    We investigated the physicochemical properties of pH-sensitive hydroxyethyl cellulose (HEC)/hyaluronic acid (HA) complex hydrogels containing isoliquiritigenin (ILTG), and discussed potential applications as transdermal delivery systems for the treatment of skin lesions caused by pH imbalance. HA has skin compatibility and pH functional groups and HEC serves as scaffold to build hydrogels with varied HCE:HA mass ratio. Hydrogels were synthesized via chemical cross-linking, and three-dimensional network structures were characterized via scanning electron microscopy (SEM). The swelling properties and polymer ratios of the hydrogels were investigated at pH values in the range 1-13. HECHA13 (i.e., an HEC:HA mass ratio of 1:3) was found to have optimal rheological and adhesive properties, and was used to investigate the drug release efficiency as a function of pH; the efficiency was greater than 70% at pH 7. Antimicrobial activity assays against Propionibacterium acnes were conducted to take advantage of the pH-sensitive properties of HECHA13. At pH 7, we found that HECHA13, which contained ILTG, inhibited the growth of P. acnes. Furthermore, HECHA13 was found to exhibit excellent permeability into the skin, which penetrated mostly via the hair follicle. These results indicate that this pH-sensitive hydrogel is effective as a transdermal delivery system for antimicrobial therapeutics, with potential applications in the treatment of acne. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Non-animal methods to predict skin sensitization (II): an assessment of defined approaches *.

    Science.gov (United States)

    Kleinstreuer, Nicole C; Hoffmann, Sebastian; Alépée, Nathalie; Allen, David; Ashikaga, Takao; Casey, Warren; Clouet, Elodie; Cluzel, Magalie; Desprez, Bertrand; Gellatly, Nichola; Göbel, Carsten; Kern, Petra S; Klaric, Martina; Kühnl, Jochen; Martinozzi-Teissier, Silvia; Mewes, Karsten; Miyazawa, Masaaki; Strickland, Judy; van Vliet, Erwin; Zang, Qingda; Petersohn, Dirk

    2018-05-01

    Skin sensitization is a toxicity endpoint of widespread concern, for which the mechanistic understanding and concurrent necessity for non-animal testing approaches have evolved to a critical juncture, with many available options for predicting sensitization without using animals. Cosmetics Europe and the National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods collaborated to analyze the performance of multiple non-animal data integration approaches for the skin sensitization safety assessment of cosmetics ingredients. The Cosmetics Europe Skin Tolerance Task Force (STTF) collected and generated data on 128 substances in multiple in vitro and in chemico skin sensitization assays selected based on a systematic assessment by the STTF. These assays, together with certain in silico predictions, are key components of various non-animal testing strategies that have been submitted to the Organization for Economic Cooperation and Development as case studies for skin sensitization. Curated murine local lymph node assay (LLNA) and human skin sensitization data were used to evaluate the performance of six defined approaches, comprising eight non-animal testing strategies, for both hazard and potency characterization. Defined approaches examined included consensus methods, artificial neural networks, support vector machine models, Bayesian networks, and decision trees, most of which were reproduced using open source software tools. Multiple non-animal testing strategies incorporating in vitro, in chemico, and in silico inputs demonstrated equivalent or superior performance to the LLNA when compared to both animal and human data for skin sensitization.

  5. Experimental studies on the nature of sensitive skin.

    Science.gov (United States)

    Kligman, A M; Sadiq, Iqbal; Zhen, Yaxian; Crosby, Marilyn

    2006-11-01

    In the USA, Europe and Japan 40 to 50% of women report that they have sensitive skin, defined as abnormal sub-clinical sensory responses to drugs, cosmetics and toiletries in the absence of visible signs of irritation. Itching, burning, stinging and tightness are the commonest complaints, which mainly afflict women. Manufacturers of skin care products have made available a large variety of products which are designed for persons with sensitive skin. Such products are not required by regulatory agencies to submit evidence of safety and efficacy, allowing marketers to make claims that are often exaggerated, irrational and even preposterous. The consumer with self-assessed sensitive skin has no way of judging which products are likely to be most beneficial and least harmful. The marketplace is awash with products for which there is no evidence that the rosy claims have been substantiated by appropriate testing procedures. There is no internationally accepted consensus regarding the criteria which define sensitive skin. Many papers have been published in the last 15 years, mainly originating from industry, which express widely differing views regarding what constitutes sensitive skin. For some, any adverse reaction to a product topically applied to sensitive skin, including breakouts, redness, scaling etc., a panoply of adverse reactions which is virtually meaningless. Others include environmental factors as causative, including cold, dry wind, heat and high humidity, solar radiation, etc., which add to the manifest complexities of the subject. This is the first paper in a series which provides a comprehensive review of the subject, emphasizing the all too many controversies and confusions arising from the lack of a consensus regarding the identification, classification, epidemiology, prevalence and pathogenesis of sensitive skin. Sensitive skin is a biologic reality and not a psychological, fashionable fantasy on the part of impressionable women. There is an urgent

  6. Fabrics Protect Sensitive Skin from UV Rays

    Science.gov (United States)

    2009-01-01

    Late Johnson Space Center engineer Dr. Robert Dotts headed a team to develop cool suits for children suffering from life-threatening sun sensitivities. Dotts hoped to develop ultraviolet-blocking technology in a fabric that -- unlike in a bulky space suit -- could remain comfortable, light, and breathable in the sun and heat. The team worked with SPF 4 US LLC (SPF) of Madison, Wisconsin to design ultraviolet-blocking cool suits, which protect sun-sensitive patients and enable them to experience life outdoors safely. Using knowledge gained during the NASA collaboration, SPF created an entire line of ultraviolet-blocking apparel.

  7. In chemico skin sensitization risk assessment of botanical ingredients.

    Science.gov (United States)

    Avonto, Cristina; Chittiboyina, Amar G; Sadrieh, Nakissa; Vukmanovic, Stanislav; Khan, Ikhlas A

    2018-03-24

    Skin sensitization risk assessment of botanical ingredients is necessary for consumers' protection and occupational hazard identification. There are currently very few available alternative methods that can assist in the evaluation of complex mixtures. Chemical methods can provide essential information in a timely manner and thus help to reduce the need for in vivo testing, and they can complement and facilitate targeted in vitro assays. In the present work, the applicability of the high-throughput screening with dansyl cysteamine (DCYA) method for the systematic evaluation of skin sensitization of complex botanicals was explored. Botanical ingredients of four unrelated plant species were obtained and tested with the high-throughput fluorescence method at three concentrations. To illustrate the minimal matrix effects of the tested extracts on the developed method, the least DCYA-reactive extract (Rosa canina) was spiked with known sensitizers at different concentrations. The data obtained from the four plant extracts and the spiking experiments with known sensitizers, suggest that the high-throughput screening-DCYA method can be successfully applied for estimating the skin sensitization potential of complex botanical matrices. This is the first report of an attempt to develop a versatile in chemico method for the rapid detection of reactive skin sensitizers in complex botanical extracts, which could complement the battery of existing validated, non-animal methods. Copyright © 2018 John Wiley & Sons, Ltd.

  8. Quantitative relationship between the local lymph node assay and human skin sensitization assays.

    Science.gov (United States)

    Schneider, K; Akkan, Z

    2004-06-01

    The local lymph node assay (LLNA) is a new test method which allows for the quantitative assessment of sensitizing potency in the mouse. Here, we investigate the quantitative correlation between results from the LLNA and two human sensitization tests--specifically, human repeat insult patch tests (HRIPTs) and human maximization tests (HMTs). Data for 57 substances were evaluated, of which 46 showed skin sensitizing properties in human tests, whereas 11 yielded negative results in humans. For better comparability data from mouse and human tests were transformed to applied doses per skin area, which ranged over four orders of magnitude for the substances considered. Regression analysis for the 46 human sensitizing substances revealed a significant positive correlation between the LLNA and human tests. The correlation was better between LLNA and HRIPT data (n=23; r=0.77) than between LLNA and HMT data (n=38; r=0.65). The observed scattering of data points is related to various uncertainties, in part associated with insufficiencies of data from older HMT studies. Predominantly negative results in the LLNA for another 11 substances which showed no skin sensitizing activity in human maximization tests further corroborate the correspondence between LLNA and human tests. Based on this analysis, the LLNA can be considered a reliable basis for relative potency assessments for skin sensitizers. Proposals are made for the regulatory exploitation of the LLNA: four potency groups can be established, and assignment of substances to these groups according to the outcome of the LLNA can be used to characterize skin sensitizing potency in substance-specific assessments. Moreover, based on these potency groups, a more adequate consideration of sensitizing substances in preparations becomes possible. It is proposed to replace the current single concentration limit for skin sensitizers in preparations, which leads to an all or nothing classification of a preparation as sensitizing to

  9. Prognostic value of asymptomatic skin sensitization to aeroallergens

    DEFF Research Database (Denmark)

    Bødtger, Uffe

    2004-01-01

    condition affecting 8-30% of the population when using a local standard panel of aeroallergens. Clinically, immediate but not late-phase reactions are induced by allergen challenge. Absent eosinophil stimulation and migration and low IL-5 levels appear to be sentinel mechanisms. Prospective studies show...... positive skin test must be ruled out before allergen avoidance measures are initiated. SUMMARY: Surprisingly few papers exist on asymptomatic skin sensitization epidemiology and immunology, despite the intriguing question as to why symptoms do not develop in IgE-sensitized patients. It is a common...

  10. Prediction of skin sensitization potency using machine learning approaches.

    Science.gov (United States)

    Zang, Qingda; Paris, Michael; Lehmann, David M; Bell, Shannon; Kleinstreuer, Nicole; Allen, David; Matheson, Joanna; Jacobs, Abigail; Casey, Warren; Strickland, Judy

    2017-07-01

    The replacement of animal use in testing for regulatory classification of skin sensitizers is a priority for US federal agencies that use data from such testing. Machine learning models that classify substances as sensitizers or non-sensitizers without using animal data have been developed and evaluated. Because some regulatory agencies require that sensitizers be further classified into potency categories, we developed statistical models to predict skin sensitization potency for murine local lymph node assay (LLNA) and human outcomes. Input variables for our models included six physicochemical properties and data from three non-animal test methods: direct peptide reactivity assay; human cell line activation test; and KeratinoSens™ assay. Models were built to predict three potency categories using four machine learning approaches and were validated using external test sets and leave-one-out cross-validation. A one-tiered strategy modeled all three categories of response together while a two-tiered strategy modeled sensitizer/non-sensitizer responses and then classified the sensitizers as strong or weak sensitizers. The two-tiered model using the support vector machine with all assay and physicochemical data inputs provided the best performance, yielding accuracy of 88% for prediction of LLNA outcomes (120 substances) and 81% for prediction of human test outcomes (87 substances). The best one-tiered model predicted LLNA outcomes with 78% accuracy and human outcomes with 75% accuracy. By comparison, the LLNA predicts human potency categories with 69% accuracy (60 of 87 substances correctly categorized). These results suggest that computational models using non-animal methods may provide valuable information for assessing skin sensitization potency. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Plasmonic light-sensitive skins of nanocrystal monolayers

    Science.gov (United States)

    Akhavan, Shahab; Gungor, Kivanc; Mutlugun, Evren; Demir, Hilmi Volkan

    2013-04-01

    We report plasmonically coupled light-sensitive skins of nanocrystal monolayers that exhibit sensitivity enhancement and spectral range extension with plasmonic nanostructures embedded in their photosensitive nanocrystal platforms. The deposited plasmonic silver nanoparticles of the device increase the optical absorption of a CdTe nanocrystal monolayer incorporated in the device. Controlled separation of these metallic nanoparticles in the vicinity of semiconductor nanocrystals enables optimization of the photovoltage buildup in the proposed nanostructure platform. The enhancement factor was found to depend on the excitation wavelength. We observed broadband sensitivity improvement (across 400-650 nm), with a 2.6-fold enhancement factor around the localized plasmon resonance peak. The simulation results were found to agree well with the experimental data. Such plasmonically enhanced nanocrystal skins hold great promise for large-area UV/visible sensing applications.

  12. Integrated Computational Solution for Predicting Skin Sensitization Potential of Molecules.

    Directory of Open Access Journals (Sweden)

    Konda Leela Sarath Kumar

    Full Text Available Skin sensitization forms a major toxicological endpoint for dermatology and cosmetic products. Recent ban on animal testing for cosmetics demands for alternative methods. We developed an integrated computational solution (SkinSense that offers a robust solution and addresses the limitations of existing computational tools i.e. high false positive rate and/or limited coverage.The key components of our solution include: QSAR models selected from a combinatorial set, similarity information and literature-derived sub-structure patterns of known skin protein reactive groups. Its prediction performance on a challenge set of molecules showed accuracy = 75.32%, CCR = 74.36%, sensitivity = 70.00% and specificity = 78.72%, which is better than several existing tools including VEGA (accuracy = 45.00% and CCR = 54.17% with 'High' reliability scoring, DEREK (accuracy = 72.73% and CCR = 71.44% and TOPKAT (accuracy = 60.00% and CCR = 61.67%. Although, TIMES-SS showed higher predictive power (accuracy = 90.00% and CCR = 92.86%, the coverage was very low (only 10 out of 77 molecules were predicted reliably.Owing to improved prediction performance and coverage, our solution can serve as a useful expert system towards Integrated Approaches to Testing and Assessment for skin sensitization. It would be invaluable to cosmetic/ dermatology industry for pre-screening their molecules, and reducing time, cost and animal testing.

  13. QSAR Study of Skin Sensitization Using Local Lymph Node Assay Data

    Directory of Open Access Journals (Sweden)

    Eugene Demchuk

    2004-01-01

    Full Text Available Abstract: Allergic Contact Dermatitis (ACD is a common work-related skin disease that often develops as a result of repetitive skin exposures to a sensitizing chemical agent. A variety of experimental tests have been suggested to assess the skin sensitization potential. We applied a method of Quantitative Structure-Activity Relationship (QSAR to relate measured and calculated physical-chemical properties of chemical compounds to their sensitization potential. Using statistical methods, each of these properties, called molecular descriptors, was tested for its propensity to predict the sensitization potential. A few of the most informative descriptors were subsequently selected to build a model of skin sensitization. In this work sensitization data for the murine Local Lymph Node Assay (LLNA were used. In principle, LLNA provides a standardized continuous scale suitable for quantitative assessment of skin sensitization. However, at present many LLNA results are still reported on a dichotomous scale, which is consistent with the scale of guinea pig tests, which were widely used in past years. Therefore, in this study only a dichotomous version of the LLNA data was used. To the statistical end, we relied on the logistic regression approach. This approach provides a statistical tool for investigating and predicting skin sensitization that is expressed only in categorical terms of activity and nonactivity. Based on the data of compounds used in this study, our results suggest a QSAR model of ACD that is based on the following descriptors: nDB (number of double bonds, C-003 (number of CHR3 molecular subfragments, GATS6M (autocorrelation coefficient and HATS6m (GETAWAY descriptor, although the relevance of the identified descriptors to the continuous ACD QSAR has yet to be shown. The proposed QSAR model gives a percentage of positively predicted responses of 83% on the training set of compounds, and in cross validation it correctly identifies 79% of

  14. Measurements of skin friction in water using surface stress sensitive films

    International Nuclear Information System (INIS)

    Crafton, J W; Fonov, S D; Jones, E G; Goss, L P; Forlines, R A; Fontaine, A

    2008-01-01

    The measurement of skin friction on hydrodynamic surfaces is of significant value for the design of advanced naval technology, particularly at high Reynolds numbers. Here we report on the development of a new sensor for measurement of skin friction and pressure that operates in both air and water. This sensor is based on an elastic polymer film that deforms under the action of applied normal and tangential loads. Skin friction and pressure gradients are determined by monitoring these deformations and then solving an inverse problem using a finite element model of the elastic film. This technique is known as surface stress sensitive films. In this paper, we describe the development of a sensor package specifically designed for two-dimensional skin friction measurements at a single point. The package has been developed with the goal of making two-dimensional measurements of skin friction in water. Quantitative measurements of skin friction are performed on a high Reynolds number turbulent boundary layer in the 12 inch water tunnel at Penn State University. These skin friction measurements are verified by comparing them to measurements obtained with a drag plate as well as by performing two-dimensional velocity measurements above the sensor using a laser Doppler velocimetry system. The results indicate that the sensor skin friction measurements are accurate to better than 5% and repeatable to better than 2%. The directional sensitivity of the sensor is demonstrated by positioning the sensor at several orientations to the flow. A final interesting feature of this sensor is that it is sensitive to pressure gradients, not to static pressure changes. This feature should prove useful for monitoring the skin friction on a seafaring vessel as the operating depth is changed

  15. EPA Releases Draft Policy to Reduce Animal Testing for Skin Sensitization

    Science.gov (United States)

    The document, Draft Interim Science Policy: Use of Alternative Approaches for Skin Sensitization as a Replacement for Laboratory Animal Testing, describes the science behind the non-animal alternatives that can now be used to identify skin sensitization.

  16. Asymptomatic skin sensitization to birch predicts later development of birch pollen allergy in adults

    DEFF Research Database (Denmark)

    Bodtger, Uffe; Poulsen, Lars K.; Malling, Hans-Jørgen

    2003-01-01

    The skin prick test is the allergologic test of choice, but asymptomatic skin sensitization to aeroallergens is common. However, no data in the literature describe the clinical phenotype of asymptomatic sensitized adults.......The skin prick test is the allergologic test of choice, but asymptomatic skin sensitization to aeroallergens is common. However, no data in the literature describe the clinical phenotype of asymptomatic sensitized adults....

  17. Skin care products can aggravate epidermal function: studies in a murine model suggest a pathogenic role in sensitive skin.

    Science.gov (United States)

    Li, Zhengxiao; Hu, Lizhi; Elias, Peter M; Man, Mao-Qiang

    2018-02-01

    Sensitive skin is defined as a spectrum of unpleasant sensations in response to a variety of stimuli. However, only some skin care products provoke cutaneous symptoms in individuals with sensitive skin. Hence, it would be useful to identify products that could provoke cutaneous symptoms in individuals with sensitive skin. To assess whether vehicles, as well as certain branded skin care products, can alter epidermal function following topical applications to normal mouse skin. Following topical applications of individual vehicle or skin care product to C57BL/6J mice twice daily for 4 days, transepidermal water loss (TEWL) rates, stratum corneum (SC) hydration and skin surface pH were measured on treated versus untreated mouse skin with an MPA5 device and pH 900 pH meter. Our results show that all tested products induced abnormalities in epidermal functions of varying severity, including elevations in TEWL and skin surface pH, and reduced SC hydration. Our results suggest that mice can serve as a predictive model that could be used to evaluate the potential safety of skin care products in humans with sensitive skin. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Mechanistic applicability domain classification of a local lymph node assay dataset for skin sensitization.

    Science.gov (United States)

    Roberts, David W; Patlewicz, Grace; Kern, Petra S; Gerberick, Frank; Kimber, Ian; Dearman, Rebecca J; Ryan, Cindy A; Basketter, David A; Aptula, Aynur O

    2007-07-01

    The goal of eliminating animal testing in the predictive identification of chemicals with the intrinsic ability to cause skin sensitization is an important target, the attainment of which has recently been brought into even sharper relief by the EU Cosmetics Directive and the requirements of the REACH legislation. Development of alternative methods requires that the chemicals used to evaluate and validate novel approaches comprise not only confirmed skin sensitizers and non-sensitizers but also substances that span the full chemical mechanistic spectrum associated with skin sensitization. To this end, a recently published database of more than 200 chemicals tested in the mouse local lymph node assay (LLNA) has been examined in relation to various chemical reaction mechanistic domains known to be associated with sensitization. It is demonstrated here that the dataset does cover the main reaction mechanistic domains. In addition, it is shown that assignment to a reaction mechanistic domain is a critical first step in a strategic approach to understanding, ultimately on a quantitative basis, how chemical properties influence the potency of skin sensitizing chemicals. This understanding is necessary if reliable non-animal approaches, including (quantitative) structure-activity relationships (Q)SARs, read-across, and experimental chemistry based models, are to be developed.

  19. Skin subtype categorization based on a new questionnaire for Korean women.

    Science.gov (United States)

    Park, Byeong Jin; Kim, Jeong Eun; Ko, JooYeon; Kim, Myoung Shin; Park, Eun Joo; Lee, Ga Young; Lee, Jong Hee; Na, Jung Im; Chang, Sung Eun

    2018-03-02

    Several terms have been used to characterize skin types. However, these are not based on evident dermatologic definitions, which usually include subjective and psychological properties. The objective of this study is to establish a new practical questionnaire to classify skin subtypes in Korean women to establish treatment and skin care guidance. Eight experts developed consensus statements about skin types and created a questionnaire. The content was categorized into four major subtypes: dry or non-dry; oily or nonoily; sensitive or nonsensitive; and pigmented or nonpigmented. A total of 512 patients completed the questionnaire. Correlations with age, skin Fitzpatrick's phototypes, and dermatologic comorbidities were analyzed. Korean women commonly have oily skin but complain of dryness after cleansing. They are especially sensitive to skin care products and prone to developing pigmentary lesions. There was a trend in the proportion of dry skin subtype that increased as pigmented skin increased and oily skin decreased with advanced age. The proportion of sensitive skin was higher in patients with dermatologic comorbidities. The proportion of the pigmented skin was higher in darker Fitzpatrick skin phototypes. This is the first questionnaire established for Korean women to classify practical skin subtypes and may provide a basis for treating various skin conditions.

  20. Skin Sensitive Difference of Human Body Sections under Clothing-Smirnov Test of Skin Surface Temperatures' Dynamic Changing

    Institute of Scientific and Technical Information of China (English)

    LI Jun; WU Hai-yan; WANG Yun-yi

    2004-01-01

    Skin sensitive difference of human body sections under clothing is the theoretic foundation of thermal insulation clothing design.By a new method of researching on clothing comfort perception,the skin temperature live changing procedure of human body sections affected by the same cold stimulation is inspected.Furthermore with the Smirnov test the skin temperatures dynamic changing patterns of main human body sections are obtained.

  1. A Prototype Lip Balm: Summary of Three Dermatological Studies Demonstrating Safety and Acceptability for Sensitive Skin.

    Science.gov (United States)

    Nisbet, Stephanie

    Data were generated from three studies to assess the tolerability and acceptability of a prototype cosmetic lip balm. Dermatological assessments of topical compatibility (primary and cumulative irritability and sensitization), photoirritant and topical photosensitizer potential, and acceptability for safe use of a prototype cosmetic lip balm on sensitive skin are summarized. In Study 1, the product was applied to the volunteers' backs under a semiocclusive patch followed by patch removal/reapplication over 6 weeks to assess the irritant and allergic potential of the product. Dermatological assessments were performed at the beginning and end of the study or when there was evidence of positivity or adverse event. Study 2 was conducted by applying the product to the volunteers' backs under a semiocclusive patch, followed by patch removal/reapplication and irradiation of the test area with ultraviolet A (UVA) radiation at various intervals over 5 weeks. Dermatological assessments were performed to assess the product's role in the induction of photoirritancy and photosensitization. Clinical and subjective assessments for acceptability were obtained during Study 3 in volunteers with a diagnosis of sensitive skin and those who used the product as per instructions for use during the study period. The data generated from the three studies demonstrated no evidence of primary or cumulative dermal irritation or of dermal sensitization. In addition, no photoirritation potential or photosensitization potential was observed. As assessed by dermatologic monitoring and subject diary entries, the prototype lip balm did not cause irritation or sensitization reactions when used for 28 days in volunteers with a diagnosis of sensitive skin. Based on these findings, the prototype lip balm can be considered suitable for use for people with sensitive skin.

  2. Is skin penetration a determining factor in skin sensitization potential and potency? Refuting the notion of a LogKow threshold for Skin Sensitization

    Science.gov (United States)

    Summary:Background. It is widely accepted that substances that cannot penetrate through the skin will not be sensitisers. Thresholds based on relevant physicochemical parameters such as a LogKow > 1 and a MW < 500, are assumed and widely accepted as self-evident truths. Objective...

  3. Evaluation of the performance of the reduced local lymph node assay for skin sensitization testing.

    Science.gov (United States)

    Ezendam, Janine; Muller, Andre; Hakkert, Betty C; van Loveren, Henk

    2013-06-01

    The local lymph node assay (LLNA) is the preferred method for classification of sensitizers within REACH. To reduce the number of mice for the identification of sensitizers the reduced LLNA was proposed, which uses only the high dose group of the LLNA. To evaluate the performance of this method for classification, LLNA data from REACH registrations were used and classification based on all dose groups was compared to classification based on the high dose group. We confirmed previous examinations of the reduced LLNA showing that this method is less sensitive compared to the LLNA. The reduced LLNA misclassified 3.3% of the sensitizers identified in the LLNA and misclassification occurred in all potency classes and that there was no clear association with irritant properties. It is therefore not possible to predict beforehand which substances might be misclassified. Another limitation of the reduced LLNA is that skin sensitizing potency cannot be assessed. For these reasons, it is not recommended to use the reduced LLNA as a stand-alone assay for skin sensitization testing within REACH. In the future, the reduced LLNA might be of added value in a weight of evidence approach to confirm negative results obtained with non-animal approaches. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Discrimination of skin sensitizers from non-sensitizers by interleukin-1α and interleukin-6 production on cultured human keratinocytes.

    Science.gov (United States)

    Jung, Daun; Che, Jeong-Hwan; Lim, Kyung-Min; Chun, Young-Jin; Heo, Yong; Seok, Seung Hyeok

    2016-09-01

    In vitro testing methods for classifying sensitizers could be valuable alternatives to in vivo sensitization testing using animal models, such as the murine local lymph node assay (LLNA) and the guinea pig maximization test (GMT), but there remains a need for in vitro methods that are more accurate and simpler to distinguish skin sensitizers from non-sensitizers. Thus, the aim of our study was to establish an in vitro assay as a screening tool for detecting skin sensitizers using the human keratinocyte cell line, HaCaT. HaCaT cells were exposed to 16 relevant skin sensitizers and 6 skin non-sensitizers. The highest dose used was the dose causing 75% cell viability (CV75) that we determined by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The levels of extracellular production of interleukin-1α (IL-1α) and IL-6 were measured. The sensitivity of IL-1α was 63%, specificity was 83% and accuracy was 68%. In the case of IL-6, sensitivity: 69%, specificity: 83% and accuracy: 73%. Thus, this study suggests that measuring extracellular production of pro-inflammatory cytokines IL-1α and IL-6 by human HaCaT cells may potentially classify skin sensitizers from non-sensitizers. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  5. State of the art in non-animal approaches for skin sensitization testing: from individual test methods towards testing strategies.

    Science.gov (United States)

    Ezendam, Janine; Braakhuis, Hedwig M; Vandebriel, Rob J

    2016-12-01

    The hazard assessment of skin sensitizers relies mainly on animal testing, but much progress is made in the development, validation and regulatory acceptance and implementation of non-animal predictive approaches. In this review, we provide an update on the available computational tools and animal-free test methods for the prediction of skin sensitization hazard. These individual test methods address mostly one mechanistic step of the process of skin sensitization induction. The adverse outcome pathway (AOP) for skin sensitization describes the key events (KEs) that lead to skin sensitization. In our review, we have clustered the available test methods according to the KE they inform: the molecular initiating event (MIE/KE1)-protein binding, KE2-keratinocyte activation, KE3-dendritic cell activation and KE4-T cell activation and proliferation. In recent years, most progress has been made in the development and validation of in vitro assays that address KE2 and KE3. No standardized in vitro assays for T cell activation are available; thus, KE4 cannot be measured in vitro. Three non-animal test methods, addressing either the MIE, KE2 or KE3, are accepted as OECD test guidelines, and this has accelerated the development of integrated or defined approaches for testing and assessment (e.g. testing strategies). The majority of these approaches are mechanism-based, since they combine results from multiple test methods and/or computational tools that address different KEs of the AOP to estimate skin sensitization potential and sometimes potency. Other approaches are based on statistical tools. Until now, eleven different testing strategies have been published, the majority using the same individual information sources. Our review shows that some of the defined approaches to testing and assessment are able to accurately predict skin sensitization hazard, sometimes even more accurate than the currently used animal test. A few defined approaches are developed to provide an

  6. QSAR models of human data can enrich or replace LLNA testing for human skin sensitization

    OpenAIRE

    Alves, Vinicius M.; Capuzzi, Stephen J.; Muratov, Eugene; Braga, Rodolpho C.; Thornton, Thomas; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2016-01-01

    Skin sensitization is a major environmental and occupational health hazard. Although many chemicals have been evaluated in humans, there have been no efforts to model these data to date. We have compiled, curated, analyzed, and compared the available human and LLNA data. Using these data, we have developed reliable computational models and applied them for virtual screening of chemical libraries to identify putative skin sensitizers. The overall concordance between murine LLNA and human skin ...

  7. A fluorescence high throughput screening method for the detection of reactive electrophiles as potential skin sensitizers

    Science.gov (United States)

    Skin sensitization is an important toxicological end-point in the risk assessment of chemical allergens. Because of the complexity of the biological mechanisms associated with skin sensitization integrated approaches combining different chemical, biological and in silico methods are recommended to r...

  8. A fluorescence high throughput screening method for the detection of reactive electrophiles as potential skin sensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Avonto, Cristina; Chittiboyina, Amar G. [National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS 38677 (United States); Rua, Diego [The Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park, MD 20740 (United States); Khan, Ikhlas A., E-mail: ikhan@olemiss.edu [National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS 38677 (United States); Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS 38677 (United States)

    2015-12-01

    Skin sensitization is an important toxicological end-point in the risk assessment of chemical allergens. Because of the complexity of the biological mechanisms associated with skin sensitization, integrated approaches combining different chemical, biological and in silico methods are recommended to replace conventional animal tests. Chemical methods are intended to characterize the potential of a sensitizer to induce earlier molecular initiating events. The presence of an electrophilic mechanistic domain is considered one of the essential chemical features to covalently bind to the biological target and induce further haptenation processes. Current in chemico assays rely on the quantification of unreacted model nucleophiles after incubation with the candidate sensitizer. In the current study, a new fluorescence-based method, ‘HTS-DCYA assay’, is proposed. The assay aims at the identification of reactive electrophiles based on their chemical reactivity toward a model fluorescent thiol. The reaction workflow enabled the development of a High Throughput Screening (HTS) method to directly quantify the reaction adducts. The reaction conditions have been optimized to minimize solubility issues, oxidative side reactions and increase the throughput of the assay while minimizing the reaction time, which are common issues with existing methods. Thirty-six chemicals previously classified with LLNA, DPRA or KeratinoSens™ were tested as a proof of concept. Preliminary results gave an estimated 82% accuracy, 78% sensitivity, 90% specificity, comparable to other in chemico methods such as Cys-DPRA. In addition to validated chemicals, six natural products were analyzed and a prediction of their sensitization potential is presented for the first time. - Highlights: • A novel fluorescence-based method to detect electrophilic sensitizers is proposed. • A model fluorescent thiol was used to directly quantify the reaction products. • A discussion of the reaction workflow

  9. A fluorescence high throughput screening method for the detection of reactive electrophiles as potential skin sensitizers

    International Nuclear Information System (INIS)

    Avonto, Cristina; Chittiboyina, Amar G.; Rua, Diego; Khan, Ikhlas A.

    2015-01-01

    Skin sensitization is an important toxicological end-point in the risk assessment of chemical allergens. Because of the complexity of the biological mechanisms associated with skin sensitization, integrated approaches combining different chemical, biological and in silico methods are recommended to replace conventional animal tests. Chemical methods are intended to characterize the potential of a sensitizer to induce earlier molecular initiating events. The presence of an electrophilic mechanistic domain is considered one of the essential chemical features to covalently bind to the biological target and induce further haptenation processes. Current in chemico assays rely on the quantification of unreacted model nucleophiles after incubation with the candidate sensitizer. In the current study, a new fluorescence-based method, ‘HTS-DCYA assay’, is proposed. The assay aims at the identification of reactive electrophiles based on their chemical reactivity toward a model fluorescent thiol. The reaction workflow enabled the development of a High Throughput Screening (HTS) method to directly quantify the reaction adducts. The reaction conditions have been optimized to minimize solubility issues, oxidative side reactions and increase the throughput of the assay while minimizing the reaction time, which are common issues with existing methods. Thirty-six chemicals previously classified with LLNA, DPRA or KeratinoSens™ were tested as a proof of concept. Preliminary results gave an estimated 82% accuracy, 78% sensitivity, 90% specificity, comparable to other in chemico methods such as Cys-DPRA. In addition to validated chemicals, six natural products were analyzed and a prediction of their sensitization potential is presented for the first time. - Highlights: • A novel fluorescence-based method to detect electrophilic sensitizers is proposed. • A model fluorescent thiol was used to directly quantify the reaction products. • A discussion of the reaction workflow

  10. THP-1 monocytes but not macrophages as a potential alternative for CD34+ dendritic cells to identify chemical skin sensitizers

    International Nuclear Information System (INIS)

    Lambrechts, Nathalie; Verstraelen, Sandra; Lodewyckx, Hanne; Felicio, Ana; Hooyberghs, Jef; Witters, Hilda; Tendeloo, Viggo van; Cauwenberge, Paul van; Nelissen, Inge; Heuvel, Rosette van den; Schoeters, Greet

    2009-01-01

    Early detection of the sensitizing potential of chemicals is an emerging issue for chemical, pharmaceutical and cosmetic industries. In our institute, an in vitro classification model for prediction of chemical-induced skin sensitization based on gene expression signatures in human CD34 + progenitor-derived dendritic cells (DC) has been developed. This primary cell model is able to closely mimic the induction phase of sensitization by Langerhans cells in the skin, but it has drawbacks, such as the availability of cord blood. The aim of this study was to investigate whether human in vitro cultured THP-1 monocytes or macrophages display a similar expression profile for 13 predictive gene markers previously identified in DC and whether they also possess a discriminating capacity towards skin sensitizers and non-sensitizers based on these marker genes. To this end, the cell models were exposed to 5 skin sensitizers (ammonium hexachloroplatinate IV, 1-chloro-2,4-dinitrobenzene, eugenol, para-phenylenediamine, and tetramethylthiuram disulfide) and 5 non-sensitizers (L-glutamic acid, methyl salicylate, sodium dodecyl sulfate, tributyltin chloride, and zinc sulfate) for 6, 10, and 24 h, and mRNA expression of the 13 genes was analyzed using real-time RT-PCR. The transcriptional response of 7 out of 13 genes in THP-1 monocytes was significantly correlated with DC, whereas only 2 out of 13 genes in THP-1 macrophages. After a cross-validation of a discriminant analysis of the gene expression profiles in the THP-1 monocytes, this cell model demonstrated to also have a capacity to distinguish skin sensitizers from non-sensitizers. However, the DC model was superior to the monocyte model for discrimination of (non-)sensitizing chemicals.

  11. Prediction of skin sensitizers using alternative methods to animal experimentation.

    Science.gov (United States)

    Johansson, Henrik; Lindstedt, Malin

    2014-07-01

    Regulatory frameworks within the European Union demand that chemical substances are investigated for their ability to induce sensitization, an adverse health effect caused by the human immune system in response to chemical exposure. A recent ban on the use of animal tests within the cosmetics industry has led to an urgent need for alternative animal-free test methods that can be used for assessment of chemical sensitizers. To date, no such alternative assay has yet completed formal validation. However, a number of assays are in development and the understanding of the biological mechanisms of chemical sensitization has greatly increased during the last decade. In this MiniReview, we aim to summarize and give our view on the recent progress of method development for alternative assessment of chemical sensitizers. We propose that integrated testing strategies should comprise complementary assays, providing measurements of a wide range of mechanistic events, to perform well-educated risk assessments based on weight of evidence. © 2014 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  12. Immune sensitization to methylene diphenyl diisocyanate (MDI resulting from skin exposure: albumin as a carrier protein connecting skin exposure to subsequent respiratory responses

    Directory of Open Access Journals (Sweden)

    Redlich Carrie A

    2011-03-01

    Full Text Available Abstract Background Methylene diphenyl diisocyanate (MDI, a reactive chemical used for commercial polyurethane production, is a well-recognized cause of occupational asthma. The major focus of disease prevention efforts to date has been respiratory tract exposure; however, skin exposure may also be an important route for inducing immune sensitization, which may promote subsequent airway inflammatory responses. We developed a murine model to investigate pathogenic mechanisms by which MDI skin exposure might promote subsequent immune responses, including respiratory tract inflammation. Methods Mice exposed via the skin to varying doses (0.1-10% w/v of MDI diluted in acetone/olive oil were subsequently evaluated for MDI immune sensitization. Serum levels of MDI-specific IgG and IgE were measured by enzyme-linked immunosorbant assay (ELISA, while respiratory tract inflammation, induced by intranasal delivery of MDI-mouse albumin conjugates, was evaluated based on bronchoalveolar lavage (BAL. Autologous serum IgG from "skin only" exposed mice was used to detect and guide the purification/identification of skin proteins antigenically modified by MDI exposure in vivo. Results Skin exposure to MDI resulted in specific antibody production and promoted subsequent respiratory tract inflammation in animals challenged intranasally with MDI-mouse albumin conjugates. The degree of (secondary respiratory tract inflammation and eosinophilia depended upon the (primary skin exposure dose, and was maximal in mice exposed to 1% MDI, but paradoxically limited in mice receiving 10-fold higher doses (e.g. 10% MDI. The major antigenically-modified protein at the local MDI skin exposure site was identified as albumin, and demonstrated biophysical changes consistent with MDI conjugation. Conclusions MDI skin exposure can induce MDI-specific immune sensitivity and promote subsequent respiratory tract inflammatory responses and thus, may play an important role in MDI asthma

  13. QSAR models of human data can enrich or replace LLNA testing for human skin sensitization

    Science.gov (United States)

    Alves, Vinicius M.; Capuzzi, Stephen J.; Muratov, Eugene; Braga, Rodolpho C.; Thornton, Thomas; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2016-01-01

    Skin sensitization is a major environmental and occupational health hazard. Although many chemicals have been evaluated in humans, there have been no efforts to model these data to date. We have compiled, curated, analyzed, and compared the available human and LLNA data. Using these data, we have developed reliable computational models and applied them for virtual screening of chemical libraries to identify putative skin sensitizers. The overall concordance between murine LLNA and human skin sensitization responses for a set of 135 unique chemicals was low (R = 28-43%), although several chemical classes had high concordance. We have succeeded to develop predictive QSAR models of all available human data with the external correct classification rate of 71%. A consensus model integrating concordant QSAR predictions and LLNA results afforded a higher CCR of 82% but at the expense of the reduced external dataset coverage (52%). We used the developed QSAR models for virtual screening of CosIng database and identified 1061 putative skin sensitizers; for seventeen of these compounds, we found published evidence of their skin sensitization effects. Models reported herein provide more accurate alternative to LLNA testing for human skin sensitization assessment across diverse chemical data. In addition, they can also be used to guide the structural optimization of toxic compounds to reduce their skin sensitization potential. PMID:28630595

  14. Transfer of a two-tiered keratinocyte assay: IL-18 production by NCTC2544 to determine the skin sensitizing capacity and epidermal equivalent assay to determine sensitizer potency

    DEFF Research Database (Denmark)

    Teunis, Marc; Corsini, Emanuela; Smits, Mieke

    2013-01-01

    . The two tiered approach may offer an unique opportunity to provide an alternative method to the Local Lymph Node Assay (LLNA). These assays are both based on the use of human keratinocytes, which have been shown over the last two decades, to play a key role in all phases of skin sensitization....

  15. The local lymph node assay: current position in the regulatory classification of skin sensitizing chemicals.

    Science.gov (United States)

    Basketter, David A; Gerberick, G Frank; Kimber, Ian

    2007-01-01

    The local lymph node assay (LLNA) is being used increasingly in the identification of skin sensitizing chemicals for regulatory purposes. In the context of new chemicals legislation (REACH) in Europe, it is the preferred assay. The rationale for this is that the LLNA quantitative and objective approach to skin sensitization testing allied with the important animal welfare benefits that the method offers. However, as with certain guinea pig sensitization tests before it, this increasing use also brings experience with an increasingly wide range of industrial and other chemicals where the outcome of the assay does not always necessarily meet with the expectations of those conducting it. Sometimes, the result appears to be a false negative, but rather more commonly, the complaint is that the chemical represents a false positive. Against this background we have here reviewed a number of instances where false positive and false negative results have been described and have sought to reconcile science with expectation. Based on these analyses, it is our conclusion that false positives and false negatives do occur in the LLNA, as they do with any other skin sensitization assay (and indeed with all tests used for hazard identification), and that this occurs for a number of reasons. We further conclude, however, that false positive results in the LLNA, as with the guinea pig maximization test, arise most commonly via failure to distinguish what is scientifically correct from that which is unpalatable. The consequences of this confusion are discussed in the article, particularly in relation to the need to integrate both potency measurement and risk assessments into classification and labelling schemes that aim to manage potential risks to human health.

  16. Stress and skin disease quality of life: the moderating role of anxiety sensitivity social concerns.

    Science.gov (United States)

    Dixon, L J; Witcraft, S M; McCowan, N K; Brodell, R T

    2018-04-01

    Stress is an important factor in the onset, exacerbation and reoccurrence of many skin diseases. Little is known about psychological risk factors that affect the association between stress and dermatological conditions. One relevant factor that may modulate this link is anxiety sensitivity (AS) social concerns - the propensity to respond fearfully to anxiety-related sensations (e.g. sweating, flushing) owing to perceived social consequences (e.g. rejection or humiliation). To gain insight into psychological factors affecting skin disease, we examined the moderating role of AS social concerns in the relationship between stress and skin disease quality of life (QoL). Participants [n = 237 (161 female), mean ± SD age 34·18 ± 9·57 years] with active skin disease symptoms were recruited online and completed questionnaires assessing stress, AS social concerns, skin disease QoL and global skin disease symptom severity. AS social concerns moderated the association between stress and skin-related emotional and social functioning in adults with skin disease. Stress was a significant predictor of the impairment associated with skin disease. Stress was linked to skin disease-related emotional and functional impairment associated with skin disease among individuals with high AS social concerns. These results highlight the potential for AS reduction interventions to break the vicious cycle of stress and skin disease symptoms and to improve psychosocial well-being in dermatology patients. © 2017 British Association of Dermatologists.

  17. Tailoring force sensitivity and selectivity by microstructure engineering of multidirectional electronic skins

    Science.gov (United States)

    Park, Jonghwa; Kim, Jinyoung; Hong, Jaehyung; Lee, Hochan; Lee, Youngoh; Cho, Seungse; Kim, Sung-Woo; Kim, Jae Joon; Kim, Sung Youb; Ko, Hyunhyub

    2018-04-01

    Electronic skins (e-skins) with high sensitivity to multidirectional mechanical stimuli are crucial for healthcare monitoring devices, robotics, and wearable sensors. In this study, we present piezoresistive e-skins with tunable force sensitivity and selectivity to multidirectional forces through the engineered microstructure geometries (i.e., dome, pyramid, and pillar). Depending on the microstructure geometry, distinct variations in contact area and localized stress distribution are observed under different mechanical forces (i.e., normal, shear, stretching, and bending), which critically affect the force sensitivity, selectivity, response/relaxation time, and mechanical stability of e-skins. Microdome structures present the best force sensitivities for normal, tensile, and bending stresses. In particular, microdome structures exhibit extremely high pressure sensitivities over broad pressure ranges (47,062 kPa-1 in the range of <1 kPa, 90,657 kPa-1 in the range of 1-10 kPa, and 30,214 kPa-1 in the range of 10-26 kPa). On the other hand, for shear stress, micropillar structures exhibit the highest sensitivity. As proof-of-concept applications in healthcare monitoring devices, we show that our e-skins can precisely monitor acoustic waves, breathing, and human artery/carotid pulse pressures. Unveiling the relationship between the microstructure geometry of e-skins and their sensing capability would provide a platform for future development of high-performance microstructured e-skins.

  18. Analysis of Publically Available Skin Sensitization Data from REACH Registrations 2008–2014

    Science.gov (United States)

    Luechtefeld, Thomas; Maertens, Alexandra; Russo, Daniel P.; Rovida, Costanza; Zhu, Hao; Hartung, Thomas

    2017-01-01

    Summary The public data on skin sensitization from REACH registrations already included 19,111 studies on skin sensitization in December 2014, making it the largest repository of such data so far (1,470 substances with mouse LLNA, 2,787 with GPMT, 762 with both in vivo and in vitro and 139 with only in vitro data). 21% were classified as sensitizers. The extracted skin sensitization data was analyzed to identify relationships in skin sensitization guidelines, visualize structural relationships of sensitizers, and build models to predict sensitization. A chemical with molecular weight > 500 Da is generally considered non-sensitizing owing to low bioavailability, but 49 sensitizing chemicals with a molecular weight > 500 Da were found. A chemical similarity map was produced using PubChem’s 2D Tanimoto similarity metric and Gephi force layout visualization. Nine clusters of chemicals were identified by Blondel’s module recognition algorithm revealing wide module-dependent variation. Approximately 31% of mapped chemicals are Michael’s acceptors but alone this does not imply skin sensitization. A simple sensitization model using molecular weight and five ToxTree structural alerts showed a balanced accuracy of 65.8% (specificity 80.4%, sensitivity 51.4%), demonstrating that structural alerts have information value. A simple variant of k-nearest neighbors outperformed the ToxTree approach even at 75% similarity threshold (82% balanced accuracy at 0.95 threshold). At higher thresholds, the balanced accuracy increased. Lower similarity thresholds decrease sensitivity faster than specificity. This analysis scopes the landscape of chemical skin sensitization, demonstrating the value of large public datasets for health hazard prediction. PMID:26863411

  19. Repair of DNA damage in light sensitive human skin diseases

    Energy Technology Data Exchange (ETDEWEB)

    Horkay, I.; Varga, L.; Tam' asi P., Gundy, S.

    1978-12-01

    Repair of uv-light induced DNA damage and changes in the semiconservative DNA synthesis were studied by in vitro autoradiography in the skin of patients with lightdermatoses (polymorphous light eruption, porphyria cutanea tarda, erythropoietic protoporphyria) and xeroderma pigmentosum as well as in that of healthy controls. In polymorphous light eruption the semiconservative DNA replication rate was more intensive in the area of the skin lesions and in the repeated phototest site, the excision repair synthesis appeared to be unaltered. In cutaneous prophyrias a decreased rate of the repair incorporation could be detected. Xeroderma pigmentosum was characterized by a strongly reduced repair synthesis.

  20. 20170921 - An evaluation of selected (Q)SARs/expert systems for the Prediction of Skin Sensitization Potential (ASCCT)

    Science.gov (United States)

    Predictive testing to characterize substances for their skin sensitization potential has historically been based on animal models such as the Local Lymph Node Assay (LLNA) and the Guinea Pig Maximization Test (GPMT). In recent years, EU regulations have provided a strong incentiv...

  1. Dendritic cells and skin sensitization: Biological roles and uses in hazard identification

    International Nuclear Information System (INIS)

    Ryan, Cindy A.; Kimber, Ian; Basketter, David A.; Pallardy, Marc; Gildea, Lucy A.; Gerberick, G. Frank

    2007-01-01

    Recent advances have been made in our understanding of the roles played by cutaneous dendritic cells (DCs) in the induction of contact allergy. A number of associated changes in epidermal Langerhans cell phenotype and function required for effective skin sensitization are providing the foundations for the development of cellular assays (using DC and DC-like cells) for skin sensitization hazard identification. These alternative approaches to the identification and characterization of skin sensitizing chemicals were the focus of a Workshop entitled 'Dendritic Cells and Skin Sensitization: Biological Roles and Uses in Hazard Identification' that was given at the annual Society of Toxicology meeting held March 6-9, 2006 in San Diego, California. This paper reports information that was presented during the Workshop

  2. Influence of skin cold sensation threshold in the occurrence of dental sensitivity during dental bleaching: a placebo controlled clinical trial

    OpenAIRE

    Vanessa Rahal; Marjorie de Oliveira Gallinari; Juliana Stuginski Barbosa; Reynaldo Leite Martins-Junior; Paulo Henrique dos Santos; Luciano Tavares Angelo Cintra; André Luiz Fraga Briso

    2018-01-01

    Abstract Objective This study verified the occurrence of dental sensitivity in patients submitted to a 35% hydrogen peroxide based product (Whiteness HP Maxx 35% – FGM), skin cold sensation threshold (SCST) and its influence on dental sensitivity. Material and Methods Sixty volunteers were divided into 4 groups (n = 15), according to SCST (low: GI and GIII, and high: GII and IV) and bleaching treatment (hydrogen peroxide: GI and GII, and placebo: GIII and GIV). SCST was determined in the in...

  3. Human skin wetness perception: psychophysical and neurophysiological bases

    Science.gov (United States)

    Filingeri, Davide; Havenith, George

    2015-01-01

    The ability to perceive thermal changes in the surrounding environment is critical for survival. However, sensing temperature is not the only factor among the cutaneous sensations to contribute to thermoregulatory responses in humans. Sensing skin wetness (i.e. hygrosensation) is also critical both for behavioral and autonomic adaptations. Although much has been done to define the biophysical role of skin wetness in contributing to thermal homeostasis, little is known on the neurophysiological mechanisms underpinning the ability to sense skin wetness. Humans are not provided with skin humidity receptors (i.e., hygroreceptors) and psychophysical studies have identified potential sensory cues (i.e. thermal and mechanosensory) which could contribute to sensing wetness. Recently, a neurophysiological model of human wetness sensitivity has been developed. In helping clarifying the peripheral and central neural mechanisms involved in sensing skin wetness, this model has provided evidence for the existence of a specific human hygrosensation strategy, which is underpinned by perceptual learning via sensory experience. Remarkably, this strategy seems to be shared by other hygroreceptor-lacking animals. However, questions remain on whether these sensory mechanisms are underpinned by specific neuromolecular pathways in humans. Although the first study on human wetness perception dates back to more than 100 years, it is surprising that the neurophysiological bases of such an important sensory feature have only recently started to be unveiled. Hence, to provide an overview of the current knowledge on human hygrosensation, along with potential directions for future research, this review will examine the psychophysical and neurophysiological bases of human skin wetness perception. PMID:27227008

  4. Use of genotoxicity information in the development of integrated testing strategies (ITS) for skin sensitization.

    Science.gov (United States)

    Mekenyan, Ovanes; Patlewicz, Grace; Dimitrova, Gergana; Kuseva, Chanita; Todorov, Milen; Stoeva, Stoyanka; Kotov, Stefan; Donner, E Maria

    2010-10-18

    Skin sensitization is an end point of concern for various legislation in the EU, including the seventh Amendment to the Cosmetics Directive and Registration Evaluation, Authorisation and Restriction of Chemicals (REACH). Since animal testing is a last resort for REACH or banned (from 2013 onward) for the Cosmetics Directive, the use of intelligent/integrated testing strategies (ITS) as an efficient means of gathering necessary information from alternative sources (e.g., in vitro, (Q)SARs, etc.) is gaining widespread interest. Previous studies have explored correlations between mutagenicity data and skin sensitization data as a means of exploiting information from surrogate end points. The work here compares the underlying chemical mechanisms for mutagenicity and skin sensitization in an effort to evaluate the role mutagenicity information can play as a predictor of skin sensitization potential. The Tissue Metabolism Simulator (TIMES) hybrid expert system was used to compare chemical mechanisms of both end points since it houses a comprehensive set of established structure-activity relationships for both skin sensitization and mutagenicity. The evaluation demonstrated that there is a great deal of overlap between skin sensitization and mutagenicity structural alerts and their underlying chemical mechanisms. The similarities and differences in chemical mechanisms are discussed in light of available experimental data. A number of new alerts for mutagenicity were also postulated for inclusion into TIMES. The results presented show that mutagenicity information can provide useful insights on skin sensitization potential as part of an ITS and should be considered prior to any in vivo skin sensitization testing being initiated.

  5. Non-animal methods to predict skin sensitization (I): the Cosmetics Europe database.

    Science.gov (United States)

    Hoffmann, Sebastian; Kleinstreuer, Nicole; Alépée, Nathalie; Allen, David; Api, Anne Marie; Ashikaga, Takao; Clouet, Elodie; Cluzel, Magalie; Desprez, Bertrand; Gellatly, Nichola; Goebel, Carsten; Kern, Petra S; Klaric, Martina; Kühnl, Jochen; Lalko, Jon F; Martinozzi-Teissier, Silvia; Mewes, Karsten; Miyazawa, Masaaki; Parakhia, Rahul; van Vliet, Erwin; Zang, Qingda; Petersohn, Dirk

    2018-05-01

    Cosmetics Europe, the European Trade Association for the cosmetics and personal care industry, is conducting a multi-phase program to develop regulatory accepted, animal-free testing strategies enabling the cosmetics industry to conduct safety assessments. Based on a systematic evaluation of test methods for skin sensitization, five non-animal test methods (DPRA (Direct Peptide Reactivity Assay), KeratinoSens TM , h-CLAT (human cell line activation test), U-SENS TM , SENS-IS) were selected for inclusion in a comprehensive database of 128 substances. Existing data were compiled and completed with newly generated data, the latter amounting to one-third of all data. The database was complemented with human and local lymph node assay (LLNA) reference data, physicochemical properties and use categories, and thoroughly curated. Focused on the availability of human data, the substance selection resulted nevertheless resulted in a high diversity of chemistries in terms of physico-chemical property ranges and use categories. Predictivities of skin sensitization potential and potency, where applicable, were calculated for the LLNA as compared to human data and for the individual test methods compared to both human and LLNA reference data. In addition, various aspects of applicability of the test methods were analyzed. Due to its high level of curation, comprehensiveness, and completeness, we propose our database as a point of reference for the evaluation and development of testing strategies, as done for example in the associated work of Kleinstreuer et al. We encourage the community to use it to meet the challenge of conducting skin sensitization safety assessment without generating new animal data.

  6. Prediction of Skin Sensitization with a Particle Swarm Optimized Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Chenzhong Cao

    2009-07-01

    Full Text Available Skin sensitization is the most commonly reported occupational illness, causing much suffering to a wide range of people. Identification and labeling of environmental allergens is urgently required to protect people from skin sensitization. The guinea pig maximization test (GPMT and murine local lymph node assay (LLNA are the two most important in vivo models for identification of skin sensitizers. In order to reduce the number of animal tests, quantitative structure-activity relationships (QSARs are strongly encouraged in the assessment of skin sensitization of chemicals. This paper has investigated the skin sensitization potential of 162 compounds with LLNA results and 92 compounds with GPMT results using a support vector machine. A particle swarm optimization algorithm was implemented for feature selection from a large number of molecular descriptors calculated by Dragon. For the LLNA data set, the classification accuracies are 95.37% and 88.89% for the training and the test sets, respectively. For the GPMT data set, the classification accuracies are 91.80% and 90.32% for the training and the test sets, respectively. The classification performances were greatly improved compared to those reported in the literature, indicating that the support vector machine optimized by particle swarm in this paper is competent for the identification of skin sensitizers.

  7. Prediction of Skin Sensitization with a Particle Swarm Optimized Support Vector Machine

    Science.gov (United States)

    Yuan, Hua; Huang, Jianping; Cao, Chenzhong

    2009-01-01

    Skin sensitization is the most commonly reported occupational illness, causing much suffering to a wide range of people. Identification and labeling of environmental allergens is urgently required to protect people from skin sensitization. The guinea pig maximization test (GPMT) and murine local lymph node assay (LLNA) are the two most important in vivo models for identification of skin sensitizers. In order to reduce the number of animal tests, quantitative structure-activity relationships (QSARs) are strongly encouraged in the assessment of skin sensitization of chemicals. This paper has investigated the skin sensitization potential of 162 compounds with LLNA results and 92 compounds with GPMT results using a support vector machine. A particle swarm optimization algorithm was implemented for feature selection from a large number of molecular descriptors calculated by Dragon. For the LLNA data set, the classification accuracies are 95.37% and 88.89% for the training and the test sets, respectively. For the GPMT data set, the classification accuracies are 91.80% and 90.32% for the training and the test sets, respectively. The classification performances were greatly improved compared to those reported in the literature, indicating that the support vector machine optimized by particle swarm in this paper is competent for the identification of skin sensitizers. PMID:19742136

  8. Gentle cleansing and moisturizing for patients with atopic dermatitis and sensitive skin.

    Science.gov (United States)

    Cheong, Wai Kwong

    2009-01-01

    Atopic dermatitis is a common condition characterized by pruritus, inflammation, and dryness of the skin. Inflammation disrupts the barrier function of the stratum corneum, predisposing the skin to be dry, and increases susceptibility to irritants and secondary bacterial infection. Sensitive skin is common, reported by 40-50% of women and 30% of men in the US, Europe, and Japan. Basic requirements in managing eczema and sensitive skin include effective cleansers that do not compromise skin barrier integrity, alleviation of skin dryness, and restoration of skin barrier function through the use of therapeutic moisturizers. The selection of a skin cleanser is therefore an important part of managing these conditions. Studies have reported clinical improvement with the use of soap-free cleansers in combination with topical treatments. While topical corticosteroids and immunosuppressive agents are mainstays of treatment for atopic dermatitis, therapeutic moisturizers are important adjuncts. Moisturizers improve skin hydration, reduce susceptibility to irritation, restore the integrity of the stratum corneum, and enhance the efficacy of topical corticosteroids.

  9. Touch perceptions across skin sites: differences between sensitivity, direction discrimination and pleasantness

    Directory of Open Access Journals (Sweden)

    Rochelle eAckerley

    2014-02-01

    Full Text Available Human skin is innervated with different tactile afferents over the body, which are found at varying densities. We investigate how the relationships between tactile pleasantness, sensitivity and discrimination differ across the skin. Tactile pleasantness was assessed by stroking a soft brush over the skin, using five velocities (0.3, 1, 3, 10, 30 cm s-1, known to differentiate hedonic touch, and pleasantness ratings were gained. The ratings velocity-profile is known to correlate with firing in unmyelinated C-tactile afferents. Tactile sensitivity thresholds were determined using monofilament force detection and the tactile discrimination level was obtained in the direction discrimination of a moving probe; both tasks readily activate myelinated touch receptors. Perceptions were measured over five skin sites: forehead, arm, palm, thigh and shin. The assessment of tactile pleasantness over the skin resulted in a preference for the middle velocities (1-10 cm s-1, where higher ratings were gained compared to the slowest and fastest velocities. This preference in tactile pleasantness was found across all the skin sites, apart from at the palm, where no decrease in pleasantness for the faster stroking velocities was seen. We find that tactile sensitivity and discrimination vary across the skin, where the forehead and palm show increased acuity. Tactile sensitivity and discrimination levels also correlated significantly, although the tactile acuity did not relate to the perceived pleasantness of touch. Tactile pleasantness varied in a subtle way across skin sites, where the middle velocities were always rated as the most pleasant, but the ratings at hairy skin sites were more receptive to changes in stroking velocity. We postulate that although the mechanoreceptive afferent physiology may be different over the skin, the perception of pleasant touch can be interpreted using all of the available incoming somatosensory information in combination with

  10. Tolerance of fragranced and fragrance-free facial cleansers in adults with clinically sensitive skin.

    Science.gov (United States)

    Draelos, Zoe D; Fowler, Joseph; Larsen, Walter G; Hornby, Sidney; Walters, Russel M; Appa, Yohini

    2015-10-01

    Although mild, fragrance-free, nonfoaming cleansers generally are recommended for individuals with sensitive skin, many consumers choose fragranced foaming cleansers. The addition of hydrophobically modified polymers (HMPs) to mild facial cleansers has been shown to improve product tolerability in individuals with sensitive skin while facilitating foaming. The objective of the 2 studies reported here was to assess the tolerability of a mild, HMP-containing, foaming facial cleanser with a fragrance that was free of common allergens and irritating essential oils in patients with sensitive skin. In the first study, 8 participants with clinically diagnosed fragrance sensitivity used a gentle foaming HMP-containing facial cleanser with or without fragrance for 3 weeks. Both cleansers improved global disease severity, irritation, and erythema with similar cleansing effectiveness. The second study was a 3-week, prospective, double-blind, randomized, 2-center study of 153 participants with clinically diagnosed sensitive skin. In this study, the fragranced gentle foaming cleanser with HMP was as well tolerated as a benchmark gentle, fragrance-free, nonfoaming cleanser. Itching, irritation, and desquamation were most improved from baseline in both groups. The participant-rated effectiveness of the cleanser with HMP was similar or better than the benchmark cleanser after 3 weeks of use. In conclusion, the gentle facial cleanser with HMPs and a fragrance offers a new option for adults with sensitive skin who may prefer, and commonly use, a fragranced and foaming product.

  11. Two-tiered keratinocyte assay: IL-18 production by NCTC2544 cells to determine the skin sensitizing capacity and an epidermal equivalent assay to determine sensitizer potency

    DEFF Research Database (Denmark)

    Teunis, Marc; Corsini, Emanuela; Smits, Mieke

    2012-01-01

    the use of animals. The aim of the EU FP6 Integrated Project Sens-it-iv was to develop and optimize an integrated testing strategy consisting of in vitro, human cell based assays which will closely mimic sensitization mechanisms in vivo. These assays should be an alternative approach to the LLNA. The NCTC...... method to the LLNA. Both assays are based on the use of human keratinocytes, which have been shown, over the last two decades, to play a key role in all phases of skin sensitization. First, 4 known chemicals were tested during a transferability study in which 6 laboratories participated. Three...

  12. Predicting chemically-induced skin reactions. Part I: QSAR models of skin sensitization and their application to identify potentially hazardous compounds

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Vinicius M. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Muratov, Eugene [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Laboratory of Theoretical Chemistry, A.V. Bogatsky Physical-Chemical Institute NAS of Ukraine, Odessa 65080 (Ukraine); Fourches, Denis [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Strickland, Judy; Kleinstreuer, Nicole [ILS/Contractor Supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), P.O. Box 13501, Research Triangle Park, NC 27709 (United States); Andrade, Carolina H. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States)

    2015-04-15

    Repetitive exposure to a chemical agent can induce an immune reaction in inherently susceptible individuals that leads to skin sensitization. Although many chemicals have been reported as skin sensitizers, there have been very few rigorously validated QSAR models with defined applicability domains (AD) that were developed using a large group of chemically diverse compounds. In this study, we have aimed to compile, curate, and integrate the largest publicly available dataset related to chemically-induced skin sensitization, use this data to generate rigorously validated and QSAR models for skin sensitization, and employ these models as a virtual screening tool for identifying putative sensitizers among environmental chemicals. We followed best practices for model building and validation implemented with our predictive QSAR workflow using Random Forest modeling technique in combination with SiRMS and Dragon descriptors. The Correct Classification Rate (CCR) for QSAR models discriminating sensitizers from non-sensitizers was 71–88% when evaluated on several external validation sets, within a broad AD, with positive (for sensitizers) and negative (for non-sensitizers) predicted rates of 85% and 79% respectively. When compared to the skin sensitization module included in the OECD QSAR Toolbox as well as to the skin sensitization model in publicly available VEGA software, our models showed a significantly higher prediction accuracy for the same sets of external compounds as evaluated by Positive Predicted Rate, Negative Predicted Rate, and CCR. These models were applied to identify putative chemical hazards in the Scorecard database of possible skin or sense organ toxicants as primary candidates for experimental validation. - Highlights: • It was compiled the largest publicly-available skin sensitization dataset. • Predictive QSAR models were developed for skin sensitization. • Developed models have higher prediction accuracy than OECD QSAR Toolbox. • Putative

  13. Predicting chemically-induced skin reactions. Part I: QSAR models of skin sensitization and their application to identify potentially hazardous compounds

    International Nuclear Information System (INIS)

    Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2015-01-01

    Repetitive exposure to a chemical agent can induce an immune reaction in inherently susceptible individuals that leads to skin sensitization. Although many chemicals have been reported as skin sensitizers, there have been very few rigorously validated QSAR models with defined applicability domains (AD) that were developed using a large group of chemically diverse compounds. In this study, we have aimed to compile, curate, and integrate the largest publicly available dataset related to chemically-induced skin sensitization, use this data to generate rigorously validated and QSAR models for skin sensitization, and employ these models as a virtual screening tool for identifying putative sensitizers among environmental chemicals. We followed best practices for model building and validation implemented with our predictive QSAR workflow using Random Forest modeling technique in combination with SiRMS and Dragon descriptors. The Correct Classification Rate (CCR) for QSAR models discriminating sensitizers from non-sensitizers was 71–88% when evaluated on several external validation sets, within a broad AD, with positive (for sensitizers) and negative (for non-sensitizers) predicted rates of 85% and 79% respectively. When compared to the skin sensitization module included in the OECD QSAR Toolbox as well as to the skin sensitization model in publicly available VEGA software, our models showed a significantly higher prediction accuracy for the same sets of external compounds as evaluated by Positive Predicted Rate, Negative Predicted Rate, and CCR. These models were applied to identify putative chemical hazards in the Scorecard database of possible skin or sense organ toxicants as primary candidates for experimental validation. - Highlights: • It was compiled the largest publicly-available skin sensitization dataset. • Predictive QSAR models were developed for skin sensitization. • Developed models have higher prediction accuracy than OECD QSAR Toolbox. • Putative

  14. A simple in chemico method for testing skin sensitizing potential of chemicals using small endogenous molecules.

    Science.gov (United States)

    Nepal, Mahesh Raj; Shakya, Rajina; Kang, Mi Jeong; Jeong, Tae Cheon

    2018-06-01

    Among many of the validated methods for testing skin sensitization, direct peptide reactivity assay (DPRA) employs no cells or animals. Although no immune cells are involved in this assay, it reliably predicts the skin sensitization potential of a chemical in chemico. Herein, a new method was developed using endogenous small-molecular-weight compounds, cysteamine and glutathione, rather than synthetic peptides, to differentiate skin sensitizers from non-sensitizers with an accuracy as high as DPRA. The percent depletion of cysteamine and glutathione by test chemicals was measured by an HPLC equipped with a PDA detector. To detect small-size molecules, such as cysteamine and glutathione, a derivatization by 4-(4-dimethylaminophenylazo) benzenesulfonyl chloride (DABS-Cl) was employed prior to the HPLC analysis. Following test method optimization, a cut-off criterion of 7.14% depletion was applied to differentiate skin sensitizers from non-sensitizers in combination of the ratio of 1:25 for cysteamine:test chemical with 1:50 for glutathione:test chemical for the best predictivity among various single or combination conditions. Although overlapping HPLC peaks could not be fully resolved for some test chemicals, high levels of sensitivity (100.0%), specificity (81.8%), and accuracy (93.3%) were obtained for 30 chemicals tested, which were comparable or better than those achieved with DPRA. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Skin Segmentation Based on Graph Cuts

    Institute of Scientific and Technical Information of China (English)

    HU Zhilan; WANG Guijin; LIN Xinggang; YAN Hong

    2009-01-01

    Skin segmentation is widely used in many computer vision tasks to improve automated visualiza-tion. This paper presents a graph cuts algorithm to segment arbitrary skin regions from images. The detected face is used to determine the foreground skin seeds and the background non-skin seeds with the color probability distributions for the foreground represented by a single Gaussian model and for the background by a Gaussian mixture model. The probability distribution of the image is used for noise suppression to alle-viate the influence of the background regions having skin-like colors. Finally, the skin is segmented by graph cuts, with the regional parameter y optimally selected to adapt to different images. Tests of the algorithm on many real wodd photographs show that the scheme accurately segments skin regions and is robust against illumination variations, individual skin variations, and cluttered backgrounds.

  16. Adherence performances of pressure sensitive adhesives on a model viscoelastic synthetic film: a tool for the understanding of adhesion on the human skin.

    Science.gov (United States)

    Renvoise, Julien; Burlot, Delphine; Marin, Gérard; Derail, Christophe

    2009-02-23

    This work deals with the rheological behavior and adherence properties of pressure sensitive adhesive formulations dedicated to medical applications. We have developed a specific viscoelastic substrate which mimics adhesion on human skin to measure the adherence properties of PSAs when they are stuck on the human skin. By comparing peeling results of PSAs, dedicated to medical applications, stuck on human skin and on this viscoelastic substrate we show that this substrate, based on a blend of natural proteins, presents a better representation of the interactions occurring at the skin/adhesive interface than conventional substrates used for peel test (i.e. glass and steel).

  17. Filling the concept with data: integrating data from different in vitro and in silico assays on skin sensitizers to explore the battery approach for animal-free skin sensitization testing.

    Science.gov (United States)

    Natsch, Andreas; Emter, Roger; Ellis, Graham

    2009-01-01

    Tests for skin sensitization are required prior to the market launch of new cosmetic ingredients. Significant efforts are made to replace the current animal tests. It is widely recognized that this cannot be accomplished with a single in vitro test, but that rather the integration of results from different in vitro and in silico assays will be needed for the prediction of the skin sensitization potential of chemicals. This has been proposed as a theoretical scheme so far, but no attempts have been made to use experimental data to prove the validity of this concept. Here we thus try for the first time to fill this widely cited concept with data. To this aim, we integrate and report both novel and literature data on 116 chemicals of known skin sensitization potential on the following parameters: (1) peptide reactivity as a surrogate for protein binding, (2) induction of antioxidant/electrophile responsive element dependent luciferase activity as a cell-based assay; (3) Tissue Metabolism Simulator skin sensitization model in silico prediction; and (4) calculated octanol-water partition coefficient. The results of the in vitro assays were scaled into five classes from 0 to 4 to give an in vitro score and compared to the local lymph node assay (LLNA) data, which were also scaled from 0 to 4 (nonsensitizer/weak/moderate/strong/extreme). Different ways of evaluating these data have been assessed to rate the hazard of chemicals (Cooper statistics) and to also scale their potency. With the optimized model an overall accuracy for predicting sensitizers of 87.9% was obtained. There is a linear correlation between the LLNA score and the in vitro score. However, the correlation needs further improvement as there is still a relatively high variation in the in vitro score between chemicals belonging to the same sensitization potency class.

  18. Pressure sensitivity of flow oscillations in postocclusive reactive skin hyperemia.

    Science.gov (United States)

    Strucl, M; Peterec, D; Finderle, Z; Maver, J

    1994-05-01

    Skin blood flow was monitored using a laser-Doppler (LD) flowmeter in 21 healthy volunteers after an occlusion of the digital arteries. The peripheral vascular bed was exposed to occlusion ischemia of varying duration (1, 4, or 8 min) and to a change in digital arterial pressure produced by different positions of the arm above heart level to characterize the pattern of LD flow oscillations in postocclusive reactive hyperemia (PRH) and to elucidate the relevance of metabolic and myogenic mechanisms in governing its fundamental frequency. The descending part of the hyperemic flow was characterized by the appearance of conspicuous periodic oscillations with a mean fundamental frequency of 7.2 +/- 1.5 cycles/min (SD, n = 9), as assessed by a Fourier transform frequency analysis of 50-s sections of flow. The mean respiratory frequency during the periods of flow frequency analysis was 17.0 +/- 2.2 (SD, n = 9), and the PRH oscillations remained during apnea in all tested subjects. The area under the maximum flow curve increased significantly with prolongation of the occlusion (paired t test, P blood pressure in the digital arteries, which suggests the predominant role of a metabolic component in this part of the PRH response. In contrast, the fundamental frequency of PRH oscillations exhibited a significant decrease with a reduction in the estimated digital arterial pressure (linear regression, b = 0.08, P < 0.001; n = 12), but did not change with the prolongation of arterial occlusion despite a significant increase in mean LD flow (paired t test, P < 0.001; n = 9).(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Assessing the sensitivity of human skin hyperspectral responses to increasing anemia severity levels

    Science.gov (United States)

    Baranoski, Gladimir V. G.; Dey, Ankita; Chen, Tenn F.

    2015-09-01

    Anemia is a prevalent medical condition that seriously affects millions of people all over the world. In many regions, not only its initial detection but also its monitoring are hindered by limited access to laboratory facilities. This situation has motivated the development of a wide range of optical devices and procedures to assist physicians in these tasks. Although noticeable progress has been achieved in this area, the search for reliable, low-cost, and risk-free solutions still continues, and the strengthening of the knowledge base about this disorder and its effects is essential for the success of these initiatives. We contribute to these efforts by closely examining the sensitivity of human skin hyperspectral responses (within and outside the visible region of the light spectrum) to reduced hemoglobin concentrations associated with increasing anemia severity levels. This investigation, which involves skin specimens with distinct biophysical and morphological characteristics, is supported by controlled in silico experiments performed using a predictive light transport model and measured data reported in the biomedical literature. We also propose a noninvasive procedure to be employed in the monitoring of this condition at the point-of-care.

  20. Further development of LLNA:DAE method as stand-alone skin-sensitization testing method and applied for evaluation of relative skin-sensitizing potency between chemicals.

    Science.gov (United States)

    Yamashita, Kunihiko; Shinoda, Shinsuke; Hagiwara, Saori; Itagaki, Hiroshi

    2015-04-01

    To date, there has been no well-established local lymph node assay (LLNA) that includes an elicitation phase. Therefore, we developed a modified local lymph node assay with an elicitation phase (LLNA:DAE) to discriminate true skin sensitizers from chemicals that gave borderline positive results and previously reported this assay. To develop the LLNA:DAE method as a useful stand-alone testing method, we investigated the complete procedure for the LLNA:DAE method using hexyl cinnamic aldehyde (HCA), isoeugenol, and 2,4-dinitrochlorobenzene (DNCB) as test compounds. We defined the LLNA:DAE procedure as follows: in the dose-finding test, four concentrations of chemical applied to dorsum of the right ear on days 1, 2, and 3 and dorsum of both ears on day 10. Ear thickness and skin irritation score were measured on days 1, 3, 5, 10, and 12. Local lymph nodes were excised and weighed on day 12. The test dose for the primary LLNA:DAE study was selected as the dose that gave the highest left ear lymph node weight in the dose-finding study, or the lowest dose that produced a left ear lymph node of over 4 mg. This procedure was validated using nine different chemicals. Furthermore, qualitative relationship was observed between the degree of elicitation response in the left ear lymph node and the skin sensitizing potency of 32 chemicals tested in this study and the previous study. These results indicated that LLNA:DAE method was as first LLNA method that was able to evaluate the skin sensitizing potential and potency in elicitation response.

  1. Contactless physiological signals extraction based on skin color magnification

    Science.gov (United States)

    Suh, Kun Ha; Lee, Eui Chul

    2017-11-01

    Although the human visual system is not sufficiently sensitive to perceive blood circulation, blood flow caused by cardiac activity makes slight changes on human skin surfaces. With advances in imaging technology, it has become possible to capture these changes through digital cameras. However, it is difficult to obtain clear physiological signals from such changes due to its fineness and noise factors, such as motion artifacts and camera sensing disturbances. We propose a method for extracting physiological signals with improved quality from skin colored-videos recorded with a remote RGB camera. The results showed that our skin color magnification method reveals the hidden physiological components remarkably in the time-series signal. A Korea Food and Drug Administration-approved heart rate monitor was used for verifying the resulting signal synchronized with the actual cardiac pulse, and comparisons of signal peaks showed correlation coefficients of almost 1.0. In particular, our method can be an effective preprocessing before applying additional postfiltering techniques to improve accuracy in image-based physiological signal extractions.

  2. Influence of skin cold sensation threshold in the occurrence of dental sensitivity during dental bleaching: a placebo controlled clinical trial.

    Science.gov (United States)

    Rahal, Vanessa; Gallinari, Marjorie de Oliveira; Barbosa, Juliana Stuginski; Martins-Junior, Reynaldo Leite; Santos, Paulo Henrique Dos; Cintra, Luciano Tavares Angelo; Briso, André Luiz Fraga

    2018-01-18

    This study verified the occurrence of dental sensitivity in patients submitted to a 35% hydrogen peroxide based product (Whiteness HP Maxx 35% - FGM), skin cold sensation threshold (SCST) and its influence on dental sensitivity. Sixty volunteers were divided into 4 groups (n = 15), according to SCST (low: GI and GIII, and high: GII and IV) and bleaching treatment (hydrogen peroxide: GI and GII, and placebo: GIII and GIV). SCST was determined in the inner forearm for 6 different times using a neurosensory analyzer, the TSA II (Medoc Advanced Medical Systems, Ramat Yishai, Northern District, Israel). Dental sensitivity measurements were performed 10 different times using a thermal stimulus and an intraoral device attached to TSA II, positioned in the buccal surface of the upper right central incisor. Spontaneous dental sensitivity was also determined using the Visual Analogue Scale (VAS). Data were submitted to Student's t-test and Pearson's Correlation Test (α=0.05). SCST remained the same during bleaching treatment. Distinct responses of dental sensitivity were found in patients with low and high SCST during the first and third bleaching session (p≤0.05). The teeth submitted to the bleaching treatment became more sensitive to cold than those treated with placebo. Moreover, data obtained with TSA and VAS presented moderate correlation. Bleaching treatment increased dental sensitivity and skin cold sensation threshold might represent a determining factor in this occurrence, since low and high SCST patients had different responses to the thermal stimulus in the teeth.

  3. The pilosebaceous unit—a phthalate-induced pathway to skin sensitization

    Energy Technology Data Exchange (ETDEWEB)

    Simonsson, Carl, E-mail: carl.simonsson@chem.gu.se [Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96, Gothenburg (Sweden); Stenfeldt, Anna-Lena; Karlberg, Ann-Therese [Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96, Gothenburg (Sweden); Ericson, Marica B., E-mail: marica.ericson@physics.gu.se [Department of Physics, University of Gothenburg, SE-412 96, Gothenburg (Sweden); Jonsson, Charlotte A.M. [Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96, Gothenburg (Sweden)

    2012-10-01

    Allergic contact dermatitis (ACD) is caused by low-molecular weight compounds called haptens. It has been shown that the potency of haptens can depend on the formulation in which they are applied on the skin. Specifically the sensitization potency of isothiocyanates, a group of haptens which can be released from e.g. adhesive tapes and neoprene materials, increases with the presence of phthalates; however, the underlying mechanisms are not clear. A better understanding of the mechanisms governing the potency of haptens is important, e.g. to improve the risk assessment and the formulation of chemicals in consumer products. In this study we have explored phthalate-induced effects on the sensitization potency, skin distribution, and reactivity of fluorescent model isothiocyanate haptens using non-invasive two-photon microscopy to provide new insights regarding vehicle effects in ACD. The data presented in this paper indicate that the sensitization potency of isothiocyanates increases when applied in combination with dibutylphthalate due to a specific uptake via the pilosebaceous units. The results highlight the importance of shunt pathways when evaluating the bioavailability of skin sensitizers. The findings also indicate that vehicle-dependent hapten reactivity towards stratum corneum proteins regulates the bioavailability, and thus the potency, of skin sensitizers. -- Highlights: ► Vehicle effects on sensitization potency were investigated in the LLNA. ► In vivo cutaneous absorption of contact sensitizers was visualized using TPM. ► Sensitizing potency of isothiocyanates depends on the presence of a phthalate. ► Phthalate induced cutaneous absorption via the pilosebaceous units. ► Vehicle-dependent reactivity regulates sensitization potency.

  4. The pilosebaceous unit—a phthalate-induced pathway to skin sensitization

    International Nuclear Information System (INIS)

    Simonsson, Carl; Stenfeldt, Anna-Lena; Karlberg, Ann-Therese; Ericson, Marica B.; Jonsson, Charlotte A.M.

    2012-01-01

    Allergic contact dermatitis (ACD) is caused by low-molecular weight compounds called haptens. It has been shown that the potency of haptens can depend on the formulation in which they are applied on the skin. Specifically the sensitization potency of isothiocyanates, a group of haptens which can be released from e.g. adhesive tapes and neoprene materials, increases with the presence of phthalates; however, the underlying mechanisms are not clear. A better understanding of the mechanisms governing the potency of haptens is important, e.g. to improve the risk assessment and the formulation of chemicals in consumer products. In this study we have explored phthalate-induced effects on the sensitization potency, skin distribution, and reactivity of fluorescent model isothiocyanate haptens using non-invasive two-photon microscopy to provide new insights regarding vehicle effects in ACD. The data presented in this paper indicate that the sensitization potency of isothiocyanates increases when applied in combination with dibutylphthalate due to a specific uptake via the pilosebaceous units. The results highlight the importance of shunt pathways when evaluating the bioavailability of skin sensitizers. The findings also indicate that vehicle-dependent hapten reactivity towards stratum corneum proteins regulates the bioavailability, and thus the potency, of skin sensitizers. -- Highlights: ► Vehicle effects on sensitization potency were investigated in the LLNA. ► In vivo cutaneous absorption of contact sensitizers was visualized using TPM. ► Sensitizing potency of isothiocyanates depends on the presence of a phthalate. ► Phthalate induced cutaneous absorption via the pilosebaceous units. ► Vehicle-dependent reactivity regulates sensitization potency.

  5. Adaptive skin detection based on online training

    Science.gov (United States)

    Zhang, Ming; Tang, Liang; Zhou, Jie; Rong, Gang

    2007-11-01

    Skin is a widely used cue for porn image classification. Most conventional methods are off-line training schemes. They usually use a fixed boundary to segment skin regions in the images and are effective only in restricted conditions: e.g. good lightness and unique human race. This paper presents an adaptive online training scheme for skin detection which can handle these tough cases. In our approach, skin detection is considered as a classification problem on Gaussian mixture model. For each image, human face is detected and the face color is used to establish a primary estimation of skin color distribution. Then an adaptive online training algorithm is used to find the real boundary between skin color and background color in current image. Experimental results on 450 images showed that the proposed method is more robust in general situations than the conventional ones.

  6. Changes in the radiation sensitivity of mouse skin during fractionated and prolonged treatments

    International Nuclear Information System (INIS)

    Ruifrok, A.C.C.; Mason, K.A.; Hunter, N.; Thames, H.D.

    1994-01-01

    Reactions of the skin of the right thigh of mice were used as an experimental model to test possible changes in the radiosensitivity of mouse skin, as represented by changes in the linear-quadratic (LQ) model parameters α and β, as a function of fractionation interval and overall treatment time. In the first series of experiments, variable numbers of 3-Gy fractions with intervals of 6, 24 or 48 h were applied, followed by top-up doses to increase the skin damage to a level that could be scored. The results showed that mouse skin is more sensitive to 3-Gy fractions applied with 48-h intervals than to 3-Gy fractions applied with 6- or 24-h intervals. In the second series of experiments we used single-dose or fractonated test treatments for previously unirradiated mice and mice treated with priming doses of 10, 20 or 30 Gy given 1-18 days before the test treatment. The sensitivity appeared to be higher after intervals of 14-18 days than after 1-10 days after priming treatments of 20 and 30 Gy. The increased sensitivity 18 days after 20 Gy was mainly the result of an increase in the β component of the LQ model; higher values of α were also determined. We conclude that the radiosensitivity of mouse skin is higher during a radiation-induced proliferative response. 28 refs., 3 figs., 7 tabs

  7. Sensitive skin at menopause; dew point and electrometric properties of the stratum corneum.

    Science.gov (United States)

    Paquet, F; Piérard-Franchimont, C; Fumal, I; Goffin, V; Paye, M; Piérard, G E

    1998-01-12

    A number of menopausal women experience skin sensitive to various environmental threats. Two panels of 15 menopausal women on or without HRT were compared. We studied the response of their stratum corneum to variations in environmental humidity, either in air or in response to an emollient. Environment dew point and electrometric measurements on the skin were recorded to search for correlations. Data show that the baseline stratum corneum hydration is influenced by the dew point. HRT improves the barrier function of the skin. The use of emollient further extends the improvement in the functional properties of skin in menopausal women. Both HRT and an emollient can counteract in part some of the deleterious effects of cold and dry weather.

  8. Assessment of phototoxicity, skin irritation, and sensitization potential of polystyrene and TiO2 nanoparticles

    Science.gov (United States)

    Park, Yoon-Hee; Jeong, Sang Hoon; Yi, Sang Min; Hyeok Choi, Byeong; Kim, Yu-Ri; Kim, In-Kyoung; Kim, Meyoung-Kon; Son, Sang Wook

    2011-07-01

    The human skin equivalent model (HSEM) is well known as an attractive alternative model for evaluation of dermal toxicity. However, only limited data are available on the usefulness of an HSEM for nanotoxicity testing. This study was designed to investigate cutaneous toxicity of polystyrene and TiO2 nanoparticles using cultured keratinocytes, an HSEM, and an animal model. In addition, we also evaluated the skin sensitization potential of nanoparticles using a local lymph node assay with incorporation of BrdU. Findings from the present study indicate that polystyrene and TiO2 nanoparticles do not induce phototoxicity, acute cutaneous irritation, or skin sensitization. Results from evaluation of the HSEMs correspond well with those from animal models. Our findings suggest that the HSEM might be a useful alternative model for evaluation of dermal nanotoxicity.

  9. Assessment of phototoxicity, skin irritation, and sensitization potential of polystyrene and TiO2 nanoparticles

    International Nuclear Information System (INIS)

    Park, Yoon-Hee; Jeong, Sang Hoon; Yi, Sang Min; Choi, Byeong Hyeok; Son, Sang Wook; Kim, Yu-Ri; Kim, In-Kyoung; Kim, Meyoung-Kon

    2011-01-01

    The human skin equivalent model (HSEM) is well known as an attractive alternative model for evaluation of dermal toxicity. However, only limited data are available on the usefulness of an HSEM for nanotoxicity testing. This study was designed to investigate cutaneous toxicity of polystyrene and TiO 2 nanoparticles using cultured keratinocytes, an HSEM, and an animal model. In addition, we also evaluated the skin sensitization potential of nanoparticles using a local lymph node assay with incorporation of BrdU. Findings from the present study indicate that polystyrene and TiO 2 nanoparticles do not induce phototoxicity, acute cutaneous irritation, or skin sensitization. Results from evaluation of the HSEMs correspond well with those from animal models. Our findings suggest that the HSEM might be a useful alternative model for evaluation of dermal nanotoxicity.

  10. An Animal Model of Trichloroethylene-Induced Skin Sensitization in BALB/c Mice.

    Science.gov (United States)

    Wang, Hui; Zhang, Jia-xiang; Li, Shu-long; Wang, Feng; Zha, Wan-sheng; Shen, Tong; Wu, Changhao; Zhu, Qi-xing

    2015-01-01

    Trichloroethylene (TCE) is a major occupational hazard and environmental contaminant that can cause multisystem disorders in the form of occupational medicamentosa-like dermatitis. Development of dermatitis involves several proinflammatory cytokines, but their role in TCE-mediated dermatitis has not been examined in a well-defined experimental model. In addition, few animal models of TCE sensitization are available, and the current guinea pig model has apparent limitations. This study aimed to establish a model of TCE-induced skin sensitization in BALB/c mice and to examine the role of several key inflammatory cytokines on TCE sensitization. The sensitization rate of dorsal painted group was 38.3%. Skin edema and erythema occurred in TCE-sensitized groups, as seen in 2,4-dinitrochlorobenzene (DNCB) positive control. Trichloroethylene sensitization-positive (dermatitis [+]) group exhibited increased thickness of epidermis, inflammatory cell infiltration, swelling, and necrosis in dermis and around hair follicle, but ear painted group did not show these histological changes. The concentrations of serum proinflammatory cytokines including tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-2 were significantly increased in 24, 48, and 72 hours dermatitis [+] groups treated with TCE and peaked at 72 hours. Deposition of TNF-α, IFN-γ, and IL-2 into the skin tissue was also revealed by immunohistochemistry. We have established a new animal model of skin sensitization induced by repeated TCE stimulations, and we provide the first evidence that key proinflammatory cytokines including TNF-α, IFN-γ, and IL-2 play an important role in the process of TCE sensitization. © The Author(s) 2015.

  11. An evaluation of costs and effects of a nutrient-based skin care program as a component of prevention of skin tears in an extended convalescent center.

    Science.gov (United States)

    Groom, Marjorie; Shannon, Ronald J; Chakravarthy, Debashish; Fleck, Cynthia A

    2010-01-01

    A decision model was developed in a pilot study comparing a regimen using a skin care product line containing active ingredients and nutrients with a commercially available alternative skin care regimen in an elderly convalescent care hospital-based center. Using a decision-tree model, skin treatment with a nutrient-based skin care (NBSC) formulation was compared with products without nutrients. The number of skin-tear-free days was the primary outcome measure. A cost-effectiveness ratio was calculated for each skin treatment as the average cost for reaching a particular outcome. Incidence of skin tear data was collected from residents in a convalescent center from 2004 to 2005. An independent t test was used to compare differences in the number of skin tears between periods when NBSC and other formulations were used. All costs in the decision model were adjusted to 2007 dollars. Sensitivity analysis was used to test uncertain data. The NBSC provided more skin-tear-free days and was less costly than the use of non-NBSC products. The expected skin-tear-free days for a patient in the model treated with NBSC were 179.7 days compared with 154.6 days for non-NBSC products, yielding an incremental effect of 25.1 days. The expected cost of preventing skin tears and treatment via skin treatment per patient in the NBSC group was $281.00 versus $324.10 for periods when other products were used. The NBSC had a lower projected cost for prevention of skin tears and more skin-tear-free days when compared with non-NBSC products.

  12. Biodegradable Polymers Induce CD54 on THP-1 Cells in Skin Sensitization Test.

    Science.gov (United States)

    Jung, Yeon Suk; Kato, Reiko; Tsuchiya, Toshie

    2011-01-01

    Currently, nonanimal methods of skin sensitization testing for various chemicals, biodegradable polymers, and biomaterials are being developed in the hope of eliminating the use of animals. The human cell line activation test (h-CLAT) is a skin sensitization assessment that mimics the functions of dendritic cells (DCs). DCs are specialized antigen-presenting cells, and they interact with T cells and B cells to initiate immune responses. Phenotypic changes in DCs, such as the production of CD86 and CD54 and internalization of MHC class II molecules, have become focal points of the skin sensitization test. In this study, we used h-CLAT to assess the effects of biodegradable polymers. The results showed that several biodegradable polymers increased the expression of CD54, and the relative skin sensitizing abilities of biodegradable polymers were PLLG (75 : 25) < PLLC (40 : 60) < PLGA (50 : 50) < PCG (50 : 50). These results may contribute to the creation of new guidelines for the use of biodegradable polymers in scaffolds or allergenic hazards.

  13. Biodegradable Polymers Induce CD54 on THP-1 Cells in Skin Sensitization Test

    Directory of Open Access Journals (Sweden)

    Yeon Suk Jung

    2011-01-01

    Full Text Available Currently, nonanimal methods of skin sensitization testing for various chemicals, biodegradable polymers, and biomaterials are being developed in the hope of eliminating the use of animals. The human cell line activation test (h-CLAT is a skin sensitization assessment that mimics the functions of dendritic cells (DCs. DCs are specialized antigen-presenting cells, and they interact with T cells and B cells to initiate immune responses. Phenotypic changes in DCs, such as the production of CD86 and CD54 and internalization of MHC class II molecules, have become focal points of the skin sensitization test. In this study, we used h-CLAT to assess the effects of biodegradable polymers. The results showed that several biodegradable polymers increased the expression of CD54, and the relative skin sensitizing abilities of biodegradable polymers were PLLG (75 : 25 < PLLC (40 : 60 < PLGA (50 : 50 < PCG (50 : 50. These results may contribute to the creation of new guidelines for the use of biodegradable polymers in scaffolds or allergenic hazards.

  14. Comparison of the skin sensitizing potential of unsaturated compounds as assessed by the murine local lymph node assay (LLNA) and the guinea pig maximization test (GPMT).

    Science.gov (United States)

    Kreiling, R; Hollnagel, H M; Hareng, L; Eigler, D; Lee, M S; Griem, P; Dreessen, B; Kleber, M; Albrecht, A; Garcia, C; Wendel, A

    2008-06-01

    The skin sensitization potential of eight unsaturated and one saturated lipid (bio)chemicals was tested in both the LLNA and the GPMT to address the hypothesis that chemicals with unsaturated carbon-carbon double bonds may result in a higher number of unspecific (false positive) results in the LLNA compared to the GPMT. Seven substances (oleic acid, linoleic acid, linolenic acid, undecylenic acid, maleic acid, squalene and octinol) gave clear positive results in the LLNA (stimulation index (SI)> or = 3) and thus would require labelling as skin sensitizer. Fumaric acid and succinic acid gave clearly negative results. In the GPMT, besides some sporadic skin reactions, reproducible skin reactions indicating an allergic response were found in a few animals for four test substances. Based on the GPMT results, only undecylenic acid would have to be classified and labelled as a skin sensitizer according to the European Dangerous Substance Directive (67/548/EEC) (results for linoleic acid were inconclusive), while the other seven test substances would not require labelling. Possible mechanisms for unspecific skin cell stimulation and lymph node responses are discussed. In conclusion, the suitability of the LLNA for unsaturated compounds bearing structural similarity to the tested substances should be carefully considered and the GPMT should remain available as an accepted test method for skin sensitization hazard identification.

  15. Predicting chemically-induced skin reactions. Part I: QSAR models of skin sensitization and their application to identify potentially hazardous compounds

    Science.gov (United States)

    Alves, Vinicius M.; Muratov, Eugene; Fourches, Denis; Strickland, Judy; Kleinstreuer, Nicole; Andrade, Carolina H.; Tropsha, Alexander

    2015-01-01

    Repetitive exposure to a chemical agent can induce an immune reaction in inherently susceptible individuals that leads to skin sensitization. Although many chemicals have been reported as skin sensitizers, there have been very few rigorously validated QSAR models with defined applicability domains (AD) that were developed using a large group of chemically diverse compounds. In this study, we have aimed to compile, curate, and integrate the largest publicly available dataset related to chemically-induced skin sensitization, use this data to generate rigorously validated and QSAR models for skin sensitization, and employ these models as a virtual screening tool for identifying putative sensitizers among environmental chemicals. We followed best practices for model building and validation implemented with our predictive QSAR workflow using random forest modeling technique in combination with SiRMS and Dragon descriptors. The Correct Classification Rate (CCR) for QSAR models discriminating sensitizers from non-sensitizers were 71–88% when evaluated on several external validation sets, within a broad AD, with positive (for sensitizers) and negative (for non-sensitizers) predicted rates of 85% and 79% respectively. When compared to the skin sensitization module included in the OECD QSAR toolbox as well as to the skin sensitization model in publicly available VEGA software, our models showed a significantly higher prediction accuracy for the same sets of external compounds as evaluated by Positive Predicted Rate, Negative Predicted Rate, and CCR. These models were applied to identify putative chemical hazards in the ScoreCard database of possible skin or sense organ toxicants as primary candidates for experimental validation. PMID:25560674

  16. Contrasting effects of ultraviolet-A and ultraviolet B exposure on induction of contact sensitivity in human skin

    DEFF Research Database (Denmark)

    Skov, Lone; Hansen, Henrik; Barker, J. N.

    1997-01-01

    Ultraviolet-B (UVB), in addition to direct effects on DNA, induces immunological changes in the skin that predispose to the development of skin cancer. Whether ultraviolet-A (UVA) induces similar changes is unknown. This effect can be investigated in humans in vivo using epicutaneous antigens...... as a model of tumour antigens. Volunteers (n = 46) were randomly assigned to received no sensitization, sensitization with the allergen diphenylcyclopropenone (DPCP) on non-UV-exposed normal skin, or sensitization with DPCP on skin exposed to three minimal erythema doses (MED) of either UVA or UVB radiation...... the immunization rate compared with sensitization on non-irradiated skin (P UVA radiation did not result in a decreased immunization rate compared with non-irradiated skin. These results indicate that in humans erythemagenic...

  17. Roughness based perceptual analysis towards digital skin imaging system with haptic feedback.

    Science.gov (United States)

    Kim, K

    2016-08-01

    To examine psoriasis or atopic eczema, analyzing skin roughness by palpation is essential to precisely diagnose skin diseases. However, optical sensor based skin imaging systems do not allow dermatologists to touch skin images. To solve the problem, a new haptic rendering technology that can accurately display skin roughness must be developed. In addition, the rendering algorithm must be able to filter spatial noises created during 2D to 3D image conversion without losing the original roughness on the skin image. In this study, a perceptual way to design a noise filter that will remove spatial noises and in the meantime recover maximized roughness is introduced by understanding human sensitivity on surface roughness. A visuohaptic rendering system that can provide a user with seeing and touching digital skin surface roughness has been developed including a geometric roughness estimation method from a meshed surface. In following, a psychophysical experiment was designed and conducted with 12 human subjects to measure human perception with the developed visual and haptic interfaces to examine surface roughness. From the psychophysical experiment, it was found that touch is more sensitive at lower surface roughness, and vice versa. Human perception with both senses, vision and touch, becomes less sensitive to surface distortions as roughness increases. When interact with both channels, visual and haptic interfaces, the performance to detect abnormalities on roughness is greatly improved by sensory integration with the developed visuohaptic rendering system. The result can be used as a guideline to design a noise filter that can perceptually remove spatial noises while recover maximized roughness values from a digital skin image obtained by optical sensors. In addition, the result also confirms that the developed visuohaptic rendering system can help dermatologists or skin care professionals examine skin conditions by using vision and touch at the same time. © 2015

  18. Increased Sensitization to Mold Allergens Measured by Intradermal Skin Testing following Hurricanes.

    Science.gov (United States)

    Saporta, Diego; Hurst, David

    2017-01-01

    Objective . To report on changes in sensitivity to mold allergens determined by changes in intradermal skin testing reactivity, after exposure to two severe hurricanes. Methods . A random, retrospective allergy charts review divided into 2 groups of 100 patients each: Group A, patients tested between 2003 and 2010 prior to hurricanes, and Group B, patients tested in 2014 and 2015 following hurricanes. Reactivity to eighteen molds was determined by intradermal skin testing. Test results, age, and respiratory symptoms were recorded. Chi-square test determined reactivity/sensitivity differences between groups. Results . Posthurricane patients had 34.6 times more positive results ( p hurricanes ( p hurricanes ( p hurricanes. This supports climatologists' hypothesis that environmental changes resulting from hurricanes can be a health risk as reflected in increased allergic sensitivities and symptoms and has significant implications for physicians treating patients from affected areas.

  19. Polyvalent type IV sensitizations to multiple fragrances and a skin protection cream in a metal worker.

    Science.gov (United States)

    Tanko, Zita; Shab, Arna; Diepgen, Thomas Ludwig; Weisshaar, Elke

    2009-06-01

    Fragrances are very common in everyday products. A metalworker with chronic hand eczema and previously diagnosed type IV sensitizations to epoxy resin, balsam of Peru, fragrance mix and fragrance mix II was diagnosed with additional type IV sensitizations to geraniol, hydroxycitronellal, lilial, tree moss, oak moss absolute, citral, citronellol, farnesol, Lyral, fragrance mix II and fragrance mix (with sorbitan sesquioleate). In addition, a type IV sensitization to the skin protection cream containing geraniol and citronellol used at the workplace was detected, and deemed occupationally relevant in this case. The patient could have had contact to fragrances through private use of cosmetics and detergents. On the other hand, the fragrance-containing skin protection cream supports occupational exposure. This case report demonstrates that fragrance contact allergy has to be searched for and clarified individually, which requires a thorough history and a detailed analysis of the work place.

  20. The abdominal skin of female Sprague-Dawley rats is more sensitive than the back skin to drug-induced phototoxicity.

    Science.gov (United States)

    Kuga, Kazuhiro; Yasuno, Hironobu; Sakai, Yumi; Harada, Yumiko; Shimizu, Fumi; Miyamoto, Yumiko; Takamatsu, Yuki; Miyamoto, Makoto; Sato, Keiichiro

    2017-11-01

    In vivo phototoxicity studies are important to predict drug-induced phototoxicity in humans; however, a standard methodology has not established. To determine differences in sensitivity to drug-induced phototoxicity among various skin sites, we evaluated phototoxic reactions in the back and abdominal skin of female Sprague-Dawley rats orally dosed with phototoxic drugs (pirfenidone, 8-methoxysoraren, doxycycline, and lomefloxacin) or a non-phototoxic drug (gatifloxacin) followed by solar-simulated light irradiation comprising 18J/cm 2 ultraviolet A. Tissue reactions were evaluated by macroscopic and microscopic examination and immunohistochemistry for γ-H2AX, and tissue concentrations of pirfenidone, doxycycline, and lomefloxacin were measured by tandem mass spectrometry. In addition, the thicknesses of the skin layers at both sites were measured in drug-naïve rats. The abdominal skin showed more severe reactions to all phototoxic drugs than the back skin, whereas the minimal erythema dose in drug-naïve rats and skin concentrations of each drug were comparable between the sites. Furthermore, histopathological lesions and γ-H2AX-positive cells in the abdominal skin were detected in deeper layers than in the back skin. The stratum corneum and dermis in the abdominal skin were significantly thinner than in the back skin, indicating a difference in the depth of light penetration and potentially contributing to the site differences observed in sensitivity to phototoxicity. Gatifloxacin did not induce any phototoxic reactions at either site. In conclusion, the abdominal skin is more sensitive to drug-induced phototoxicity than the back skin and may represent a preferable site for irradiation in this rat phototoxicity model. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Are basophil histamine release and high affinity IgE receptor expression involved in asymptomatic skin sensitization?

    DEFF Research Database (Denmark)

    Jensen, Bettina Margrethe; Assing, K; Jensen, Lone Hummelshøj

    2006-01-01

    Immunoglobulin (Ig)E-sensitized persons with positive skin prick test, but no allergy symptoms, are classified as being asymptomatic skin sensitized (AS). The allergic type 1 disease is dependant on IgE binding to the high affinity IgE-receptor (FcepsilonRI) expressed on basophils and mast cells....

  2. Migration of human antigen-presenting cells in a human skin graft onto nude mice model after contact sensitization

    NARCIS (Netherlands)

    Hoefakker, S.; Balk, H.P.; Boersma, W.J.A.; Joost, T. van; Notten, W.R.F.; Claassen, E.

    1995-01-01

    Fluorescent contact chemical allergens provoke sensitization after application on both syngeneic and allogeneic skin grafts in mice. We attempted to determine whether the functional activity in a contact sensitization response of human skin graft was affected at the level of antigen uptake and

  3. Asymptomatic skin sensitization to birch predicts later development of birch pollen allergy in adults

    DEFF Research Database (Denmark)

    Bødtger, Uffe; Poulsen, Lars K; Malling, Hans-Jørgen

    2003-01-01

    = 6) were followed through use of daily diary cards during 3 consecutive birch pollen seasons. At inclusion and at the 3-year follow-up visit, conjunctival and nasal challenges, intradermal late-phase reaction evaluation, and measurement of specific IgE were performed. RESULTS: Asymptomatic sensitized...... a clinical characterization of skin test-positive subjects without symptoms and to ascertain the predictive values of common allergologic tests. METHODS: Asymptomatic adults with positive skin prick test results for birch (n = 15), nonatopic control subjects (n = 25), and birch pollen-allergic patients (n...

  4. Sensitivity of light interaction computer model to the absorption properties of skin

    Science.gov (United States)

    Karsten, A. E.; Singh, A.

    2011-06-01

    Light based treatments offer major benefits to patients. Many of the light based treatments or diagnostic techniques need to penetrate the skin to reach the site of interest. Human skin is a highly scattering medium and the melanin in the epidermal layer of the skin is a major absorber of light in the visible and near infrared wavelength bands. The effect of increasing absorption in the epidermis is tested on skin simulating phantoms as well as on a computer model. Changing the absorption coefficient between 0.1 mm-1 and 1.0 mm-1 resulted in a decrease of light reaching 1 mm into the sample. Transmission through a 1 mm thick sample decreased from 48% to 13% and from 31% to 2% for the different scattering coefficients.

  5. An Adhesive Patch-Based Skin Biopsy Device for Molecular Diagnostics and Skin Microbiome Studies.

    Science.gov (United States)

    Yao, Zuxu; Moy, Ronald; Allen, Talisha; Jansen, Burkhard

    2017-10-01

    A number of diagnoses in clinical dermatology are currently histopathologically confirmed and this image recognition-based confirmation generally requires surgical biopsies. The increasing ability of molecular pathology to corroborate or correct a clinical diagnosis based on objective gene expression, mutation analysis, or molecular microbiome data is on the horizon and would be further supported by a tool or procedure to collect samples non-invasively. This study characterizes such a tool in form of a 'bladeless' adhesive patch-based skin biopsy device. The performance of this device was evaluated through a variety of complementary technologies including assessment of sample biomass, electron microscopy demonstrating the harvesting of layers of epidermal tissue, and isolation of RNA and DNA from epidermal skin samples. Samples were obtained by application of adhesive patches to the anatomical area of interest. Biomass assessment demonstrated collection of approximately 0.3mg of skin tissue per adhesive patch and electron microscopy confirmed the nature of the harvested epidermal skin tissue. The obtained tissue samples are stored in a stable fashion on adhesive patches over a wide range of temperatures (-80oC to +60oC) and for extended periods of time (7 days or more). Total human RNA, human genomic DNA and microbiome DNA yields were 23.35 + 15.75ng, 27.72 + 20.71ng and 576.2 + 376.8pg, respectively, in skin samples obtained from combining 4 full patches collected non-invasively from the forehead of healthy volunteers. The adhesive patch skin sampling procedure is well tolerated and provides robust means to obtain skin tissue, RNA, DNA, and microbiome samples without involving surgical biopsies. The non-invasively obtained skin samples can be shipped cost effectively at ambient temperature by mail or standard courier service, and are suitable for a variety of molecular analyses of the skin microbiome as well as of keratinocytes, T cells, dendritic cells

  6. Demonstration of tyrosinase in the vitiligo skin of human beings by a sensitive fluorometric method as well as by 14C(U)-L-tyrosine incorporation into melanin

    International Nuclear Information System (INIS)

    Husain, I.; Vijayan, E.; Ramaiah, A.; Pasricha, J.S.; Madan, N.C.

    1982-01-01

    Tyrosinase activity (Monophenol, dihydroxyphenylalanine: oxygen oxidoreductase EC 1.14.18.1) in vitiligo and normal epidermal homogenates of skin from human beings was measured by estimating beta 3,4-dihydroxyphenylalanine (dopa) by a highly sensitive fluorometric method described in this paper. The tyrosine activity in the vitiligo skin was about 4 to 37% of corresponding normal skin. The activity of tyrosinase in normal human skin from different individuals and from different regions of the body was in the range of 4 to 140 picomoles of beta 3,4-dihydroxyphenylalanine formed per min/mg protein of epidermal homogenate. The enzyme from vitiligo and normal skin was severely inhibited by substance(s) of low molecular weight. The enzyme exhibits a lag of about 4 hr in the absence of added beta 3,4-dihydroxyphenylalanine and 1 hr in presence of 5 microM dopa. Tyrosinase from the normal and vitiligo skin was inhibited by excess concentration of tyrosine. The homogenates from vitiligo skin could synthesize melanin from C14(U)-L-Tyrosine. The rate of tyrosine incorporation into melanin by the epidermal homogenates is increased by 3,4-dihydroxyphenylalanine (dopa) disproportionate to its effect on tyrosinase activity. Based on the data presented in this paper it is concluded that melanocytes are present in the vitiligo skin. A tentative hypothesis is put forward to explain the lack of melanin synthesis by the vitiligo skin under in vivo conditions, although melanocytes are present

  7. GA(2)LEN skin test study II: clinical relevance of inhalant allergen sensitizations in Europe

    DEFF Research Database (Denmark)

    Burbach, G J; Heinzerling, L M; Edenharter, G

    2009-01-01

    BACKGROUND: Skin prick testing is the standard for diagnosing IgE-mediated allergies. A positive skin prick reaction, however, does not always correlate with clinical symptoms. A large database from a Global Asthma and Allergy European Network (GA(2)LEN) study with data on clinical relevance was ...... the clinical relevance of positive skin prick tests and calls for further studies, which may, ultimately, help increase the positive predictive value of allergy testing.......BACKGROUND: Skin prick testing is the standard for diagnosing IgE-mediated allergies. A positive skin prick reaction, however, does not always correlate with clinical symptoms. A large database from a Global Asthma and Allergy European Network (GA(2)LEN) study with data on clinical relevance...... was used to determine the clinical relevance of sensitizations against the 18 most frequent inhalant allergens in Europe. The study population consisted of patients referred to one of the 17 allergy centres in 14 European countries (n = 3034, median age = 33 years). The aim of the study was to assess...

  8. A spectrofluorimetric sensor based on grape skin tissue for ...

    African Journals Online (AJOL)

    A spectrofluorimetric method based on the grape skin has been developed for the determination of Fe3+ at pH 5.0. The emission wavelength of the grape skin sensor occurs at 680 nm and the excitation wavelength at 421 nm. The fluorescence of sensor could be quenched by Fe3+ due to the complexing ability of ...

  9. Evaluation of a topical treatment for the relief of sensitive skin

    Directory of Open Access Journals (Sweden)

    Heinicke IR

    2015-07-01

    Full Text Available Ingrid R Heinicke,1 Damian H Adams,2 Tanya M Barnes,1 Kerryn A Greive1 1Ego Pharmaceuticals, Braeside, VIC, Australia; 2Mawson Institute, University of South Australia, Mawson Lakes, SA, Australia Background: Approximately, 50% of the population claim to have sensitive skin, which has created an important challenge for dermatologists and the cosmetic industry. This study evaluates the properties of QV Face Rescue Gel (Rescue Gel that contains a combination of moisturizing and anti-irritant ingredients, and which is used to relieve the symptoms of sensitive facial skin. Methods: The ability of Rescue Gel to induce collagen types I and III in cultured neonatal human foreskin fibroblasts compared to transforming growth factor beta 1, a known potent inducer of collagen types I and III, was measured using immunofluorescence staining. Furthermore, healthy volunteers were recruited to measure the potential for Rescue Gel to reduce erythema induced by solar-simulated ultraviolet radiation on the skin compared to 0.5% hydrocortisone cream (positive control as well as it's ability to decrease transepidermal water loss compared to baseline levels. In addition, the formulation was tested for its potential to be 1 nonstinging using a facial sting/discomfort assay performed on volunteers who reacted positively to lactic acid, 2 nonirritating as determined by repeat insult patch tests, and 3 noncomedogenic. Results: Rescue Gel significantly induced collagen types I and III in cultured human foreskin fibroblasts similarly to transforming growth factor beta 1. In volunteers, Rescue Gel was shown to significantly reduce erythema induced by solar-simulated ultraviolet radiation similarly to 0.5% hydrocortisone, and to significantly reduce transepidermal water loss compared to baseline levels. Further, the formulation was found to be nonstinging, nonirritating, and noncomedogenic. No adverse events were observed. Conclusion: In this study, Rescue Gel has been shown

  10. A mechanics approach to the study of pressure sensitive adhesives and human skin for transdermal drug delivery applications

    Science.gov (United States)

    Taub, Marc Barry

    Transdermal drug delivery is an alternative approach to the systemic delivery of pharmaceuticals where drugs are administered through the skin and absorbed percutaneously. This method of delivery offers several advantages over more traditional routes; most notably, the avoidance of the fast-pass metabolism of the liver and gut, the ability to offer controlled release rates, and the possibility for novel devices. Pressure sensitive adhesives (PSAs) are used to bond transdermal drug delivery devices to the skin because of their good initial and long-term adhesion, clean removability, and skin and drug compatibility. However, an understanding of the mechanics of adhesion to the dermal layer, together with quantitative and reproducible test methods for measuring adhesion, have been lacking. This study utilizes a mechanics-based approach to quantify the interfacial adhesion of PSAs bonded to selected substrates, including human dermal tissue. The delamination of PSA layers is associated with cavitation in the PSA followed by the formation of an extensive cohesive zone behind the debond tip. A quantitative metrology was developed to assess the adhesion and delamination of PSAs, such that it could be possible to easily distinguish between the adhesive characteristics of different PSA compositions and to provide a quantitative basis from which the reliability of adhesive layers bonded to substrates could be studied. A mechanics-based model was also developed to predict debonding in terms of the relevant energy dissipation mechanisms active during this process. As failure of transdermal devices may occur cohesively within the PSA layer, adhesively at the interface between the PSA and the skin, or cohesively between the corneocytes that comprise the outermost layer of the skin, it was also necessary to explore the mechanical and fracture properties of human skin. The out-of-plane delamination of corneocytes was studied by determining the strain energy release rate during

  11. Potential natural sensitizers extracted from the skin of Canarium odontophyllum fruits for dye-sensitized solar cells

    Science.gov (United States)

    Lim, Andery; Kumara, N. T. R. N.; Tan, Ai Ling; Mirza, Aminul Huq; Chandrakanthi, R. L. N.; Petra, Mohammad Iskandar; Ming, Lim Chee; Senadeera, G. K. R.; Ekanayake, Piyasiri

    2015-03-01

    Possibility of use of dye extract from skin samples of a seasonal, indigenous fruit from Borneo, namely Canarium odontophyllum, in dye sensitized solar cells (DSSCs) are explored. Three main groups of flavonoid pigments are detected and these pigments exhibit different UV-vis absorption properties, and hence showing different light harvesting capabilities. When applied in DSSCs. The detected pigment constituents of the extract consist of aurone (maritimein), anthocyanidin (pelargonidin) and anthocyanidin (cyanidin derivatives). When tested in DSSC, the highest conversion efficiency of 1.43% is exhibited by cyanidin derivatives, and this is followed by conversion efficiencies of 0.51% and 0.79% for aurone and pelargonidin, respectively. It is shown that individual pigments, like cyanidin derivatives and pelargonidin, exhibit higher power conversion efficiency when compared to that of C.odontophyllum skin pigment mixture (with a conversion efficiency of only 0.68%). The results indicate a possibility of masking effects of the pigments when used as a mixture. The acidification of C.odontophyllum skin pigments with concentrated hydrochloric acid improves the conversion efficiency of the mixture from 0.68% to 0.99%. The discussion in this paper will draw data and observations from the variation in absorption and adsorption properties, the HOMO-LUMO levels, the energy band gaps and the functional group compositions of the detected flavonoids.

  12. Estimation of Thermal Sensation Based on Wrist Skin Temperatures

    Science.gov (United States)

    Sim, Soo Young; Koh, Myung Jun; Joo, Kwang Min; Noh, Seungwoo; Park, Sangyun; Kim, Youn Ho; Park, Kwang Suk

    2016-01-01

    Thermal comfort is an essential environmental factor related to quality of life and work effectiveness. We assessed the feasibility of wrist skin temperature monitoring for estimating subjective thermal sensation. We invented a wrist band that simultaneously monitors skin temperatures from the wrist (i.e., the radial artery and ulnar artery regions, and upper wrist) and the fingertip. Skin temperatures from eight healthy subjects were acquired while thermal sensation varied. To develop a thermal sensation estimation model, the mean skin temperature, temperature gradient, time differential of the temperatures, and average power of frequency band were calculated. A thermal sensation estimation model using temperatures of the fingertip and wrist showed the highest accuracy (mean root mean square error [RMSE]: 1.26 ± 0.31). An estimation model based on the three wrist skin temperatures showed a slightly better result to the model that used a single fingertip skin temperature (mean RMSE: 1.39 ± 0.18). When a personalized thermal sensation estimation model based on three wrist skin temperatures was used, the mean RMSE was 1.06 ± 0.29, and the correlation coefficient was 0.89. Thermal sensation estimation technology based on wrist skin temperatures, and combined with wearable devices may facilitate intelligent control of one’s thermal environment. PMID:27023538

  13. Flexible polymer transistors with high pressure sensitivity for application in electronic skin and health monitoring.

    Science.gov (United States)

    Schwartz, Gregor; Tee, Benjamin C-K; Mei, Jianguo; Appleton, Anthony L; Kim, Do Hwan; Wang, Huiliang; Bao, Zhenan

    2013-01-01

    Flexible pressure sensors are essential parts of an electronic skin to allow future biomedical prostheses and robots to naturally interact with humans and the environment. Mobile biomonitoring in long-term medical diagnostics is another attractive application for these sensors. Here we report the fabrication of flexible pressure-sensitive organic thin film transistors with a maximum sensitivity of 8.4 kPa(-1), a fast response time of 15,000 cycles and a low power consumption of monitoring, which may lead to the use of flexible pressure sensors in mobile health monitoring and remote diagnostics in cardiovascular medicine.

  14. Optimization of PIXE-sensitivity for detection of Ti in thin human skin sections

    International Nuclear Information System (INIS)

    Pallon, Jan; Garmer, Mats; Auzelyte, Vaida; Elfman, Mikael; Kristiansson, Per; Malmqvist, Klas; Nilsson, Christer; Shariff, Asad; Wegden, Marie

    2005-01-01

    Modern sunscreens contain particles like TiO 2 having sizes of 25-70 nm and acting as a reflecting substance. For cosmetic reasons the particle size is minimized. Questions have been raised to what degree these nano particles penetrate the skin barrier, and how they do affect the human. The EU funded project 'Quality of skin as a barrier to ultra-fine particles' - NANODERM has started with the purpose to evaluate the possible risks of TiO 2 penetration into vital skin layers. The purpose of the work presented here was to find the optimal conditions for micro-PIXE analysis of Ti in thin skin sections. In the skin region where Ti is expected to be found, the naturally occurring major elements phosphorus, chlorine, sulphur and potassium have steep gradients and thus influence the X-ray background in a non-predictable manner. Based on experimental studies of Ti-exposed human skin sections using proton energies ranging from 1.8-2.55 MeV, the corresponding PIXE detection limits for Ti were calculated. The energy that was found to be the most favourable, 1.9 MeV, was then selected for future studies

  15. Hyperspectral Based Skin Detection for Person of Interest Identification

    Science.gov (United States)

    2015-03-01

    short-wave infrared VIS visible spectrum PCA principal component analysis FCBF Fast Correlation- Based Filter POI person of interest ANN artificial neural...an artificial neural network (ANN) that is created in MATLAB® using the Neural Network Toolbox to identify a POI based on their skin spectral data. A...identifying a POI based on skin spectral data. She identified an optimal feature subset to be used with the hyperspectral data she collected using a

  16. Influence of skin cold sensation threshold in the occurrence of dental sensitivity during dental bleaching: a placebo controlled clinical trial

    Directory of Open Access Journals (Sweden)

    Vanessa Rahal

    2018-01-01

    Full Text Available Abstract Objective This study verified the occurrence of dental sensitivity in patients submitted to a 35% hydrogen peroxide based product (Whiteness HP Maxx 35% – FGM, skin cold sensation threshold (SCST and its influence on dental sensitivity. Material and Methods Sixty volunteers were divided into 4 groups (n = 15, according to SCST (low: GI and GIII, and high: GII and IV and bleaching treatment (hydrogen peroxide: GI and GII, and placebo: GIII and GIV. SCST was determined in the inner forearm for 6 different times using a neurosensory analyzer, the TSA II (Medoc Advanced Medical Systems, Ramat Yishai, Northern District, Israel. Dental sensitivity measurements were performed 10 different times using a thermal stimulus and an intraoral device attached to TSA II, positioned in the buccal surface of the upper right central incisor. Spontaneous dental sensitivity was also determined using the Visual Analogue Scale (VAS. Data were submitted to Student's t-test and Pearson's Correlation Test (α=0.05. SCST remained the same during bleaching treatment. Results Distinct responses of dental sensitivity were found in patients with low and high SCST during the first and third bleaching session (p≤0.05. The teeth submitted to the bleaching treatment became more sensitive to cold than those treated with placebo. Moreover, data obtained with TSA and VAS presented moderate correlation. Conclusions Bleaching treatment increased dental sensitivity and skin cold sensation threshold might represent a determining factor in this occurrence, since low and high SCST patients had different responses to the thermal stimulus in the teeth.

  17. The sensitization potential of sunscreen after ablative fractional skin resurfacing using modified human repeated insult patch test.

    Science.gov (United States)

    Boonchai, Waranya; Sathaworawong, Angkana; Wongpraparut, Chanisada; Wanitphakdeedecha, Rungsima

    2015-10-01

    Ablative fractional skin resurfacing has become popular and proven to be useful in treating scars, photoaging and wrinkles. Although post-inflammatory hyperpigmentation (PIH) is the most common complication especially in dark-skinned patients like Asian. Several modalities have been used to overcome the PIH. To determine the sensitization potential of sunscreen applied immediately after ablative fractional skin resurfacing. Sixty volunteers were recruited. Of these 30 subjects were from previous ablative fractional skin resurfacing study who applied broad-spectrum sunscreen containing anti-inflammatory agent starting on the first day after resurfacing and another 30 non-resurfacing subjects had applied the same sunscreen on the intact skin. All subjects were patch/photopatch tested for sensitization study by using modified human repeated insult patch test (HRIPT). There were significantly higher sensitization rate of UV-filter, octocrylene and the sunscreen in resurfacing group than in non-resurfacing group. Early application of sunscreen after ablative fractional skin resurfacing has increased the incidence of sensitization potential of sunscreen. The sunscreen is recommended to start using from D3 after fractional ablative skin resurfacing to ensure the complete recovery of skin barrier and minimize the risk of sensitization.

  18. Sensitivity and specificity of skin tests in the diagnosis of clarithromycin allergy.

    Science.gov (United States)

    Mori, Francesca; Barni, Simona; Pucci, Neri; Rossi, Elisabetta; Azzari, Chiara; de Martino, Maurizio; Novembre, Elio

    2010-05-01

    Clarithromycin is one of the most frequently prescribed oral macrolidic antibiotics in the pediatric population. Suspected adverse reactions to clarithromycin have been frequently described by parents of children examined in pediatric allergy units, but there is a lack of reliable methods available in detecting the presence of specific IgE antibodies. To investigate the prevalence of a clarithromycin allergy in children seen in a pediatric allergy unit using standardized skin tests and oral provocation tests (OPTs). Sixty-four children were referred with a history of a clarithromycin-associated adverse drug reaction. All these children underwent skin tests and OPTs. The nonirritating intradermal skin test concentration for clarithromycin was determined in a control group of 18 children who had tolerated clarithromycin in the previous month. The threshold nonirritating intradermal concentration was established at the 10:2 dilution (0.5 mg/mL). Nine of the 64 children had an immediately positive intradermal response to the 10:2 dilution and only 1 child to the 10:3 dilution (0.05 mg/mL). None had positive skin prick test results or delayed skin responses to intradermal tests. Four of 64 children (6%) with previously described adverse reactions due to clarithromycin intake had a positive OPT reaction. When we correlated the intradermal skin test results to the OPT results, intradermal test sensitivity and specificity were 75% and 90%, respectively. Intradermal tests seem to be useful in allergologic workup in children with suspected clarithromycin hypersensitivity and may help reduce the need for OPTs.

  19. An evaluation of selected in silico models for the assessment of skin sensitization potential – performance and practical utility considerations (QSAR conference)

    Science.gov (United States)

    Skin sensitization remains an important endpoint for consumers, manufacturers and regulators. Although the development of alternative approaches to assess skin sensitization potential has been extremely active over many years, the implication of regulations such as REACH and the ...

  20. Evaluation of the skin sensitizing potency of chemicals by using the existing methods and considerations of relevance for elicitation

    DEFF Research Database (Denmark)

    Basketter, David A; Andersen, Klaus E; Liden, Carola

    2005-01-01

    be translated into practical thresholds and whether these could be set for both induction and elicitation. Examples are given for substances falling into various potency groups for skin sensitization relating to results from the local lymph node assay, the guinea pig maximization test, the Buehler method...... products, cosmetics, food and feeding stuffs, which are subject to specific community legislation. The main questions that are answered in this report are whether it would be possible to give detailed guidance on how to grade allergen potency based on the existing methods, whether such grading could...

  1. Skin Bleaching and Dermatologic Health of African and Afro-Caribbean Populations in the US: New Directions for Methodologically Rigorous, Multidisciplinary, and Culturally Sensitive Research.

    Science.gov (United States)

    Benn, Emma K T; Alexis, Andrew; Mohamed, Nihal; Wang, Yan-Hong; Khan, Ikhlas A; Liu, Bian

    2016-12-01

    Skin-bleaching practices, such as using skin creams and soaps to achieve a lighter skin tone, are common throughout the world and are triggered by cosmetic reasons that oftentimes have deep historical, economic, sociocultural, and psychosocial roots. Exposure to chemicals in the bleaching products, notably, mercury (Hg), hydroquinone, and steroids, has been associated with a variety of adverse health effects, such as Hg poisoning and exogenous ochronosis. In New York City (NYC), skin care product use has been identified as an important route of Hg exposure, especially among Caribbean-born blacks and Dominicans. However, surprisingly sparse information is available on the epidemiology of the health impacts of skin-bleaching practices among these populations. We highlight the dearth of large-scale, comprehensive, community-based, clinical, and translational research in this area, especially the limited skin-bleaching-related research among non-White populations in the US. We offer five new research directions, including investigating the known and under-studied health consequences among populations for which the skin bleach practice is newly emerging at an alarming rate using innovative laboratory and statistical methods. We call for conducting methodologically rigorous, multidisciplinary, and culturally sensitive research in order to provide insights into the root and the epidemiological status of the practice and provide evidence of exposure-outcome associations, with an ultimate goal of developing potential intervention strategies to reduce the health burdens of skin-bleaching practice.

  2. Design of flexible skin based on a mixed cruciform honeycomb

    Science.gov (United States)

    Rong, Jiaxin; Zhou, Li

    2017-04-01

    As the covering of morphing wings, flexible skin is required to provide adequate cooperation deformation, keep the smoothness of the aerodynamic configuration and bear the air load. The non-deformation direction of flexible skin is required to be restrained to keep the smoothness during morphing. This paper studies the deformation mechanisms of a cruciform honeycomb under zero Poisson's ratio constraint. The morphing capacity and in-plane modulus of the cruciform honeycomb are improved by optimizing the shape parameters of honeycomb unit. To improve the out-of-plane bending capacity, a zero Poisson's ratio mixed cruciform honeycomb is proposed by adding ribs into cruciform honeycomb, which can be used as filling material of flexible skin. The mechanical properties of the mixed honeycomb are studied by theoretical analysis and simulation. The local deformation of flexible skin under air load is also analyzed. Targeting the situation of non-uniform air load, a gradient density design scheme is referred. According to the design requirements of the variable camber trailing edge wing flexible skin, the specific design parameters and performance parameters of the skin based on the mixed honeycomb are given. The results show that the zero Poisson's ratio mixed cruciform honeycomb has a large bending rigidity itself and can have a better deformation capacity in-plane and a larger bending rigidity out-of-plane by optimizing the shape parameters. Besides, the designed skin also has advantages in driving force, deformation capacity and quality compared with conventional skin.

  3. Regression-based model of skin diffuse reflectance for skin color analysis

    Science.gov (United States)

    Tsumura, Norimichi; Kawazoe, Daisuke; Nakaguchi, Toshiya; Ojima, Nobutoshi; Miyake, Yoichi

    2008-11-01

    A simple regression-based model of skin diffuse reflectance is developed based on reflectance samples calculated by Monte Carlo simulation of light transport in a two-layered skin model. This reflectance model includes the values of spectral reflectance in the visible spectra for Japanese women. The modified Lambert Beer law holds in the proposed model with a modified mean free path length in non-linear density space. The averaged RMS and maximum errors of the proposed model were 1.1 and 3.1%, respectively, in the above range.

  4. Screening for skin-sensitizing allergens among patients with clinically suspected allergic contact dermatitis

    Directory of Open Access Journals (Sweden)

    Zahid Shakoor

    2017-09-01

    Full Text Available Objectives: To detect common skin-sensitizing agents among patients experiencing allergic contact dermatitis (ACD. Methods: This was a retrospective study of 152 patients with clinically suspected ACD who underwent patch testing in an allergy clinic at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia between January 2012 and February 2015. Of these patients, only 74 (48% patients reacted to one or more contact allergens. This group of patients included 58 (78.4% women and 16 (21.6% men (mean age: 37.8±13.8 years. Patch testing was performed using the thin-layer rapid-use epicutaneous patch test panels. Results: Nickel sulfate was the most common sensitizing agent, with 26 (35.1% patients yielding a positive result; followed by p-phenylenediamine in 17 (22.9%, butyl-tetra-phenol formaldehyde in 12 (16.2%, gold sodium thiosulfate in 10 (13.5%, and thimerosal in 6 (8.1% patients. Nickel reactivity was significantly higher among women (41.4% than among men (12.5% (p less than 0.0001. Similarly, gold reactivity among women (15.5% was also higher than among men (6.2% (p≤0.02. Conclusion: The high level of skin sensitization due to nickel, PPD, and gold in patients with ACD emphasizes the need for measures to decrease exposure to these sensitizing agents.

  5. Skin sensitization quantitative risk assessment for occupational exposure of hairdressers to hair dye ingredients.

    Science.gov (United States)

    Goebel, Carsten; Diepgen, Thomas L; Blömeke, Brunhilde; Gaspari, Anthony A; Schnuch, Axel; Fuchs, Anne; Schlotmann, Kordula; Krasteva, Maya; Kimber, Ian

    2018-06-01

    Occupational exposure of hairdressers to hair dyes has been associated with the development of allergic contact dermatitis (ACD) involving the hands. p-Phenylenediamine (PPD) and toluene-2,5-diamine (PTD) have been implicated as important occupational contact allergens. To conduct a quantitative risk assessment for the induction of contact sensitization to hair dyes in hairdressers, available data from hand rinsing studies following typical occupational exposure conditions to PPD, PTD and resorcinol were assessed. By accounting for wet work, uneven exposure and inter-individual variability for professionals, daily hand exposure concentrations were derived. Secondly, daily hand exposure was compared with the sensitization induction potency of the individual hair dye defined as the No Expected Sensitization Induction Levels (NESIL). For PPD and PTD hairdresser hand exposure levels were 2.7 and 5.9 fold below the individual NESIL. In contrast, hand exposure to resorcinol was 50 fold below the NESIL. Correspondingly, the risk assessment for PPD and PTD indicates that contact sensitization may occur, when skin protection and skin care are not rigorously applied. We conclude that awareness of health risks associated with occupational exposure to hair dyes, and of the importance of adequate protective measures, should be emphasized more fully during hairdresser education and training. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Assessment of Irritation and Sensitization Potential of Eight Baby Skin Care Products.

    Science.gov (United States)

    Galzote, Carlos; Thomas, Mini; Sachdev, Mukta

    2016-10-01

    Ethnic differences in skin sensitivity suggest that greater emphasis be focused on understanding a product's effect in diverse populations. The irritation and/or sensitization potential of 8 baby skin care products in Indian adults were evaluated using cumulative irritation tests (CIT) and human repeat insult patch testing (HRIPT) protocols. Healthy males or females aged 18 to 65 years of Indian ethnicity were treated with each of 6 products (cream, hair oil, lotion, body wash, shampoo, and baby soap) using CIT (n = 25) and HRIPT (n = 200). Baby powder and baby oil were evaluated by CIT (n = 25) and HRIPT (n = 107) in separate studies. CITs were conducted over 14 days; HRIPTs were conducted over 10 weeks. In both CIT and HRIPT, most products were considered mild, with no irritation. Baby soap and powder elicited reactions in the HRIPT induction phase, with positive challenge phase reactions (3 subjects), but were affirmed to be nonallergenic in the rechallenge phase. In these studies, 8 baby skin care products were evaluated by both CIT and HRIPT in Indian adults. The results of the studies indicated that all of the tested products were nonallergenic and nonirritating. J Drugs Dermatol. 2016;15(10):1244-1248.

  7. Food Sensitivity in Children with Acute Urticaria in Skin Prick Test: Single Center Experience

    Directory of Open Access Journals (Sweden)

    Hatice Eke Gungor

    2015-11-01

    Full Text Available Aim: Families of children with acute urticaria often think that there is food allergy in children with urticaria and insist for skin tests. In this study, it was aimed to determine whether skin prick tests are necessary in cases presented with acute urticaria, in whom other causes of acute urticaria are excluded. Material and Method: A test panel involving cow milk, egg white, wheat, hazelnut, peanut, soybean, walnut, sesame, and tuna fish antigens was applied to the children presented with acute urticaria between 1 August 2013 and 1 August 2014, in whom other causes of acute urticaria were excluded and suspected food allergy was reported by parents. Results: Overall, 574 children aged 1-14 years were included to the study. Of the patients, sensitization against at least one food antigen was detected in 22.3% (128/574 of the patients. This rate was found to be 31.9% among those younger than 3 years, while 19.3% in those older than 3 years. Overall, sensitization rates against food allergen in panel were as follows: egg white, 7.3%; wheat, 3.3%; cow milk, 2.7%,; sesame, 2.8%; hazelnut, 2.4%; soybean, 2.3%; peanut, 1.9%, walnut, 1.6%; tuna fish, 1.6%. In general, the history of patients wasn%u2019t compatible with food sensitization detected. Discussion: Sensitization to food allergens is infrequent in children presented with acute urticaria, particularly among those older than 3 years despite expressions of parent and skin prick tests seems to be unnecessary unless strongly suggestive history is present.

  8. Relevance of Cat and Dog Sensitization by Skin Prick Testing in Childhood Eczema and Asthma.

    Science.gov (United States)

    Hon, Kam Lun; Tsang, Kathy Yin Ching; Pong, Nga Hin Henry; Leung, Ting Fan

    2017-01-01

    Household animal dander has been implicated as aeroallergen in childhood atopic diseases. Many parents seek healthcare advice if household pet keeping may be detrimental in atopic eczema (AE), allergic rhinitis and asthma. We investigated if skin sensitization by cat/dog dander was associated with disease severity and quality of life in children with AE. Demographics, skin prick test (SPT) results, disease severity (Nottingham eczema severity score NESS), Children Dermatology Life Quality Index (CDLQI), blood IgE and eosinophil counts of a cohort of AE patients were reviewed. 325 AE patients followed at a pediatric dermatology clinic were evaluated. Personal history of asthma was lowest (20%) in the dog-dander-positive-group but highest (61%) in bothcat- and-dog-dander-positive group (p=0.007). Binomial logistic regression ascertained that catdander sensitization was associated with increasing age (adjusted odds ratio [aOR], 1.056; 95% Confidence Interval [CI], 1.006 to 1.109; p=0.029), dust-mite sensitization (aOR, 4.625; 95% CI, 1.444 to 14.815; p=0.010), food-allergen sensitization (aOR, 2.330; 95% CI, 1.259 to 4.310; p=0.007) and keeping-cat-ever (aOR, 7.325; 95% CI, 1.193 to 44.971; p=0.032); whereas dogdander sensitization was associated with dust-mite sensitization (aOR, 9.091; 95% CI, 1.148 to 71.980; p=0.037), food-allergen sensitization (aOR, 3.568; 95% CI, 1.341 to 9.492; p=0.011) and keeping-dog-ever (aOR, 6.809; 95% CI, 2.179 to 21.281; p=0.001). However, neither cat nor dog sensitization were associated with asthma, allergic rhinitis, parental or sibling atopic status, disease severity or quality of life. Physicians should advise parents that there is no direct correlation between AE severity, quality of life, asthma or allergic rhinitis with cutaneous sensitization to cats or dogs. Sensitized patients especially those with concomitant asthma and severe symptoms may consider non-furry alternatives if they plan to have a pet. Highly sensitized

  9. Assessment of the skin sensitization potency of eugenol and its dimers using a non-radioisotopic modification of the local lymph node assay.

    Science.gov (United States)

    Takeyoshi, Masahiro; Noda, Shuji; Yamazaki, Shunsuke; Kakishima, Hiroshi; Yamasaki, Kanji; Kimber, Ian

    2004-01-01

    Allergic contact dermatitis is a serious health problem. There is a need to identify and characterize skin sensitization hazards, particularly with respect to relative potency, so that accurate risk assessments can be developed. For these purposes the murine local lymph node assay (LLNA) was developed. Here, we have investigated further a modi fi cation of this assay, non-radioisotopic LLNA, which in place of tritiated thymidine to measure lymph node cell proliferation employs incorporation of 5-bromo-2'-deoxyuridine. Using this method we have examined the skin sensitizing activity of eugenol, a known human contact allergen, and its dimers 2,2'-dihydroxyl-3,3'-dimethoxy-5,5'-diallyl-biphenyl (DHEA) and 4,5'-diallyl-2'-hydroxy-2,3'-dimethoxy phenyl ether (DHEB). Activity in the guinea pig maximization test (GPMT) also measured. On the basis of GPMT assays, eugenol was classified as a mild skin sensitizer, DHEA as a weak skin sensitizer and DHEB as an extreme skin sensitizer. In the non-radioisotopic LLNA all chemicals were found to give positive responses insofar as each was able to provoke a stimulation index (SI) of >or=3 at one or more test concentrations. The relative skin sensitizing potency of these chemicals was evaluated in the non-radioisotopic LLNA by derivation of an ec(3) value (the concentration of chemical required to provoke an SI of 3). The ec(3) values calculated were 25.1% for eugenol, >30% for DHEA and 2.3% for DHEB. Collectively these data suggest that assessments of relative potency deriving from non-radioisotopic LLNA responses correlate well with evaluations based on GPMT results. These investigations provide support for the proposal that the non-radioisotopic LLNA may serve as an effective alternative to the GPMT where there is a need to avoid the use of radioisotopes. Copyright 2004 John Wiley & Sons, Ltd.

  10. Niacin Skin Sensitivity Is Increased in Adolescents at Ultra-High Risk for Psychosis.

    Directory of Open Access Journals (Sweden)

    Gregor E Berger

    Full Text Available Most studies provide evidence that the skin flush response to nicotinic acid (niacin stimulation is impaired in schizophrenia. However, only little is known about niacin sensitivity in the ultra-high risk (UHR phase of psychotic disorders.We compared visual ratings of niacin sensitivity between adolescents at UHR for psychosis according to the one year transition outcome (UHR-T n = 11; UHR-NT n = 55 with healthy controls (HC n = 25 and first episode schizophrenia patients (FEP n = 25 treated with atypical antipsychotics.Contrary to our hypothesis niacin sensitivity of the entire UHR group was not attenuated, but significantly increased compared to the HC group, whereas no difference could be found between the UHR-T and UHR-NT groups. As expected, niacin sensitivity of FEP was attenuated compared to HC group. In UHR individuals niacin sensitivity was inversely correlated with omega-6 and -9 fatty acids (FA, but positively correlated with phospholipase A2 (inPLA2 activity, a marker of membrane lipid repair/remodelling.Increased niacin sensitivity in UHR states likely indicates an impaired balance of eicosanoids and omega-6/-9 FA at a membrane level. Our findings suggest that the emergence of psychosis is associated with an increased mobilisation of eicosanoids prior to the transition to psychosis possibly reflecting a "pro-inflammatory state", whereas thereafter eicosanoid mobilisation seems to be attenuated. Potential treatment implications for the UHR state should be further investigated.

  11. In vitro assessment of skin sensitization, photosensitization and phototoxicity potential of commercial glyphosate-containing formulations.

    Science.gov (United States)

    de Ávila, Renato Ivan; Teixeira, Gabriel Campos; Veloso, Danillo Fabrini Maciel Costa; Moreira, Larissa Cleres; Lima, Eliana Martins; Valadares, Marize Campos

    2017-12-01

    This study evaluated the applicability of a modified Direct Peptide Reactivity Assay (DPRA) (OECD N° 442C, 2015) through the 10-fold reduction of reaction volume (micro-DPRA, mDPRA) for skin sensitization evaluation of six commercial glyphosate-containing formulations. In addition, another modification of DPRA was proposed by adding a UVA (5J/cm 2 ) irradiation step, namely photo-mDPRA, to better characterize (photo)sensitizer materials. The phototoxicity profile of pesticides was also evaluated using the 3T3 Neutral Red Uptake Phototoxicity Test (3T3-NRU-PT) (OECD N° 432, 2004). The mDPRA could represent an environmentally acceptable test approach, since it reduces costs and organic waste. Peptide depletion was greater in photo-mDPRA and changed the reactivity class of each test material, in comparison to mDPRA. Thus, the association of mDPRA with photo-mDPRA was better for correctly characterizing human (photo)sensitizer substances and pesticides. In general, cysteine depletion was greater than that of lysine for all materials tested in both mDPRA and photo-mDPRA. Furthermore, while 3T3-NRU-PT is unable to predict (photo)sensitizers, it was capable of correctly identifying the phototoxic potential of the tested agrochemical formulations. In conclusion, mDPRA plus photo-mDPRA and 3T3-NRU-PT seem to be preliminary non-animal test batteries for skin (photo)sensitization/phototoxicity assessment of chemicals, agrochemical formulations and their ingredients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Reproducibility of the heat/capsaicin skin sensitization model in healthy volunteers

    Directory of Open Access Journals (Sweden)

    Cavallone LF

    2013-11-01

    Full Text Available Laura F Cavallone,1 Karen Frey,1 Michael C Montana,1 Jeremy Joyal,1 Karen J Regina,1 Karin L Petersen,2 Robert W Gereau IV11Department of Anesthesiology, Washington University in St Louis, School of Medicine, St Louis, MO, USA; 2California Pacific Medical Center Research Institute, San Francisco, CA, USAIntroduction: Heat/capsaicin skin sensitization is a well-characterized human experimental model to induce hyperalgesia and allodynia. Using this model, gabapentin, among other drugs, was shown to significantly reduce cutaneous hyperalgesia compared to placebo. Since the larger thermal probes used in the original studies to produce heat sensitization are now commercially unavailable, we decided to assess whether previous findings could be replicated with a currently available smaller probe (heated area 9 cm2 versus 12.5–15.7 cm2.Study design and methods: After Institutional Review Board approval, 15 adult healthy volunteers participated in two study sessions, scheduled 1 week apart (Part A. In both sessions, subjects were exposed to the heat/capsaicin cutaneous sensitization model. Areas of hypersensitivity to brush stroke and von Frey (VF filament stimulation were measured at baseline and after rekindling of skin sensitization. Another group of 15 volunteers was exposed to an identical schedule and set of sensitization procedures, but, in each session, received either gabapentin or placebo (Part B.Results: Unlike previous reports, a similar reduction of areas of hyperalgesia was observed in all groups/sessions. Fading of areas of hyperalgesia over time was observed in Part A. In Part B, there was no difference in area reduction after gabapentin compared to placebo.Conclusion: When using smaller thermal probes than originally proposed, modifications of other parameters of sensitization and/or rekindling process may be needed to allow the heat/capsaicin sensitization protocol to be used as initially intended. Standardization and validation of

  13. Skin Sensitive Difference of Human Body Sections under Clothing--Multiple Analysis of Skin Surface Temperature Changes

    Institute of Scientific and Technical Information of China (English)

    李俊; 吴海燕; 张渭源

    2003-01-01

    A new researching method on clothing comfort perception is developed.By it the skin surface temperature changes and subjective psychological perception of human body sections stimulated by the same cold stimulation are studied.With the multiple comparison analysis method the changing laws of skin temperature of main human body sections is obtained.

  14. Proposal of abolition of the skin sensitivity test before equine rabies immune globulin application

    Directory of Open Access Journals (Sweden)

    CUPO Palmira

    2001-01-01

    Full Text Available An epizootic outbreak of rabies occurred in 1995 in Ribeirão Preto, SP, with 58 cases of animal rabies (54 dogs, 3 cats and 1 bat confirmed by the Pasteur Institute of São Paulo, and one human death. The need to provide care to a large number of people for the application of equine rabies immune globulin (ERIG prevented the execution of the skin sensitivity test (SST and often also the execution of desensitization, procedures routinely used up to that time at the Emergency Unit of the University Hospital of the Faculty of Medicine of Ribeirão Preto, University of São Paulo (EU-UHFMRP-USP, a reference hospital for the application of heterologous sera. In view of our positive experience of several years with the abolition of SST and of the use of premedication before the application of antivenom sera, we used a similar schedule for ERIG application. Of the 1489 victims of animal bites, 1054 (71% received ERIG; no patient was submitted to SST and all received intravenously anti-histamines (anti-H1 + anti-H2 and corticosteroids before the procedure. The patients were kept under observation for 60 to 180 minutes and no adverse reaction was observed. On the basis of these results, since December 1995 ERIG application has been decentralized in Ribeirão Preto and has become the responsibility of the Emergency Unit of the University Hospital and the Central Basic Health Unit, where the same routine is used. Since then, 4216 patients have received ERIG (1818 at the Basic Health Unit and 2398 at the EU-UHFMRP, with no problems. The ideal would be the routine use of human rabies immune globulin (HRIG in public health programs, but this is problematic, because of their high cost. However, while this does not occur, the use of SST is no longer justified at the time of application of ERIG, in view of the clinical evidence of low predictive value and low sensitivity of SST involving the application of heterologous sera. It is very important to point out

  15. Micro-patterned graphene-based sensing skins for human physiological monitoring

    Science.gov (United States)

    Wang, Long; Loh, Kenneth J.; Chiang, Wei-Hung; Manna, Kausik

    2018-03-01

    Ultrathin, flexible, conformal, and skin-like electronic transducers are emerging as promising candidates for noninvasive and nonintrusive human health monitoring. In this work, a wearable sensing membrane is developed by patterning a graphene-based solution onto ultrathin medical tape, which can then be attached to the skin for monitoring human physiological parameters and physical activity. Here, the sensor is validated for monitoring finger bending/movements and for recognizing hand motion patterns, thereby demonstrating its future potential for evaluating athletic performance, physical therapy, and designing next-generation human-machine interfaces. Furthermore, this study also quantifies the sensor’s ability to monitor eye blinking and radial pulse in real-time, which can find broader applications for the healthcare sector. Overall, the printed graphene-based sensing skin is highly conformable, flexible, lightweight, nonintrusive, mechanically robust, and is characterized by high strain sensitivity.

  16. The biological mechanisms and behavioral functions of opsin-based light detection by the skin

    Directory of Open Access Journals (Sweden)

    Jennifer L Kelley

    2016-08-01

    Full Text Available Light detection not only forms the basis of vision (via visual retinal photoreceptors, but can also occur in other parts of the body, including many non-rod/non-cone ocular cells, the pineal complex, the deep brain, and the skin. Indeed, many of the photopigments (an opsin linked to a light-sensitive 11-cis retinal chromophore that mediate color vision in the eyes of vertebrates are also present in the skin of animals such as reptiles, amphibians, crustaceans and fishes (with related photoreceptive molecules present in cephalopods, providing a localized mechanism for light detection across the surface of the body. This form of non-visual photosensitivity may be particularly important for animals that can change their coloration by altering the dispersion of pigments within the chromatophores (pigment containing cells of the skin. Thus, skin coloration may be directly color matched or tuned to both the luminance and spectral properties of the local background environment, thereby facilitating behavioral functions such as camouflage, thermoregulation, and social signaling. This review examines the diversity and sensitivity of opsin-based photopigments present in the skin and considers their putative functional roles in mediating animal behavior. Furthermore, it discusses the potential underlying biochemical and molecular pathways that link shifts in environmental light to both photopigment expression and chromatophore photoresponses. Although photoreception that occurs independently of image formation remains poorly understood, this review highlights the important role of non-visual light detection in facilitating the multiple functions of animal coloration.

  17. LLNA variability: An essential ingredient for a comprehensive assessment of non-animal skin sensitization test methods and strategies.

    Science.gov (United States)

    Hoffmann, Sebastian

    2015-01-01

    The development of non-animal skin sensitization test methods and strategies is quickly progressing. Either individually or in combination, the predictive capacity is usually described in comparison to local lymph node assay (LLNA) results. In this process the important lesson from other endpoints, such as skin or eye irritation, to account for variability reference test results - here the LLNA - has not yet been fully acknowledged. In order to provide assessors as well as method and strategy developers with appropriate estimates, we investigated the variability of EC3 values from repeated substance testing using the publicly available NICEATM (NTP Interagency Center for the Evaluation of Alternative Toxicological Methods) LLNA database. Repeat experiments for more than 60 substances were analyzed - once taking the vehicle into account and once combining data over all vehicles. In general, variability was higher when different vehicles were used. In terms of skin sensitization potential, i.e., discriminating sensitizer from non-sensitizers, the false positive rate ranged from 14-20%, while the false negative rate was 4-5%. In terms of skin sensitization potency, the rate to assign a substance to the next higher or next lower potency class was approx.10-15%. In addition, general estimates for EC3 variability are provided that can be used for modelling purposes. With our analysis we stress the importance of considering the LLNA variability in the assessment of skin sensitization test methods and strategies and provide estimates thereof.

  18. Skin sensitizer identification by IL-8 secretion and CD86 expression on THP-1 cells.

    Science.gov (United States)

    Parise, Carolina Bellini; Sá-Rocha, Vanessa Moura; Moraes, Jane Zveiter

    2015-12-25

    Substantial progress has been made in the development of alternative methods for skin sensitization in the last decade in several countries around the world. Brazil is experiencing an increasing concern about using animals for product development, since the publication of the Law 9605/1998, which prohibits the use of animals when an alternative method is available. In this way, an in vitro test to evaluate allergenic potential is a pressing need.This preliminary study started setting the use of myelomonocytic THP-1 cell line, according to the human cell line activation test (h-CLAT), already under validation process. We found that 48-h chemical exposure was necessary to identify 22 out of 23 sensitizers by the analyses of CD86 expression. In addition, the CD54 expression analyses presented a poor efficiency to discriminate sensitizers from non-sensitizers in our conditions. In view of these results, we looked for changes of pro-inflammatory interleukin profile. The IL-8 secretion analyses after 24-h chemical incubation seemed to be an alternative for CD54 expression assessing.Altogether, our findings showed that the combination of the analyses of CD86 expression and IL-8 secretion allowed predicting allergenicity.

  19. β-Adrenergic blockade does not impair the skin blood flow sensitivity to local heating in burned and nonburned skin under neutral and hot environments in children.

    Science.gov (United States)

    Rivas, Eric; McEntire, Serina J; Herndon, David N; Mlcak, Ronald P; Suman, Oscar E

    2017-05-01

    We tested the hypothesis that propranolol, a drug given to burn patients to reduce hypermetabolism/cardiac stress, may inhibit heat dissipation by changing the sensitivity of skin blood flow (SkBF) to local heating under neutral and hot conditions. In a randomized double-blind study, a placebo was given to eight burned children, while propranolol was given to 13 burned children with similar characteristics (mean±SD: 11.9±3 years, 147±20 cm, 45±23 kg, 56±12% Total body surface area burned). Nonburned children (n=13, 11.4±3 years, 152±15 cm, 52±13 kg) served as healthy controls. A progressive local heating protocol characterized SkBF responses in burned and unburned skin and nonburned control skin under the two environmental conditions (23 and 34°C) via laser Doppler flowmetry. Resting SkBF was greater in burned and unburned skin compared to the nonburned control (main effect: skin, Pburned; 38±36 unburned vs 9±8 control %SkBF max ). No difference was found for maximal SkBF capacity to local heating between groups. Additionally, dose-response curves for the sensitivity of SkBF to local heating were not different among burned or unburned skin, and nonburned control skin (EC 50 , P>.05) under either condition. Therapeutic propranolol does not negatively affect SkBF under neutral or hot environmental conditions and further compromise temperature regulation in burned children. © 2017 John Wiley & Sons Ltd.

  20. Skin

    International Nuclear Information System (INIS)

    Hunter, R.D.

    1985-01-01

    Malignant disease involving the skin represents a significant work load to the general radiotherapist and can involve interesting diagnostic and therapeutic decisions. Primary skin cancer is also relatively common and there is a need to provide an efficient service in which the first treatment is successful in the majority of patients. The reward for careful attention to technique is very considerable both in terms of clinical cancer control and functional results. Squamous cell carcinoma, basal cell carcinoma, and intra-epidermal carcinoma constitute the majority of the lesions dealt with clinically, but metastatic disease, lymphomas, and malignant melanomas are also referred regularly for opinions and may require radiotherapy. The general principle of the techniques of assessment and radiotherapeutic management to be described are equally applicable to any malignant skin tumour once the decision has been made to accept it for radiotherapy. Dosage and fractionation may have to be adjusted to allow for the nature of the disease process and the intent of the treatment

  1. Application of the KeratinoSens™ assay for assessing the skin sensitization potential of agrochemical active ingredients and formulations.

    Science.gov (United States)

    Settivari, Raja S; Gehen, Sean C; Amado, Ricardo Acosta; Visconti, Nicolo R; Boverhof, Darrell R; Carney, Edward W

    2015-07-01

    Assessment of skin sensitization potential is an important component of the safety evaluation process for agrochemical products. Recently, non-animal approaches including the KeratinoSens™ assay have been developed for predicting skin sensitization potential. Assessing the utility of the KeratinoSens™ assay for use with multi-component mixtures such as agrochemical formulations has not been previously evaluated and is a significant need. This study was undertaken to evaluate the KeratinoSens™ assay prediction potential for agrochemical formulations. The assay was conducted for 8 agrochemical active ingredients (AIs) including 3 sensitizers (acetochlor, meptyldinocap, triclopyr), 5 non-sensitizers (aminopyralid, clopyralid, florasulam, methoxyfenozide, oxyfluorfen) and 10 formulations for which in vivo sensitization data were available. The KeratinoSens™ correctly predicted the sensitization potential of all the AIs. For agrochemical formulations it was necessary to modify the standard assay procedure whereby the formulation was assumed to have a common molecular weight. The resultant approach correctly predicted the sensitization potential for 3 of 4 sensitizing formulations and all 6 non-sensitizing formulations when compared to in vivo data. Only the meptyldinocap-containing formulation was misclassified, as a result of high cytotoxicity. These results demonstrate the promising utility of the KeratinoSens™ assay for evaluating the skin sensitization potential of agrochemical AIs and formulations. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. IgE Sensitization Patterns to Commonly Consumed Foods Determined by Skin Prick Test in Korean Adults

    OpenAIRE

    Kim, Sung Ryeol; Park, Hye Jung; Park, Kyung Hee; Lee, Jae-Hyun; Park, Jung-Won

    2016-01-01

    Offending food allergens can vary with regional preferences in food consumption. In this study, we analysed sensitization rates to commonly consumed foods in Korean adults suspected of having food allergy. One hundred and thirty four subjects underwent a skin prick test (SPT) with 55 food allergens, of which 13 were made by our laboratory and the rest were commercially purchased. Of the 134 patients, 73 (54.5%) were sensitized to one or more food allergens. Sensitization to chrysalis was dete...

  3. The respiratory allergen glutaraldehyde in the local lymph node assay: sensitization by skin exposure, but not by inhalation.

    Science.gov (United States)

    van Triel, Jos J; van Bree, Bianca W J; Roberts, David W; Muijser, Hans; Duistermaat, Evert; Woutersen, Ruud A; Kuper, C Frieke

    2011-01-11

    Previously, a selection of low molecular weight contact and respiratory allergens had tested positive in both a skin and a respiratory local lymph node assay (LLNA), but formaldehyde was negative for sensitization by inhalation. To investigate whether this was due to intrinsic properties of aldehyde sensitizers, the structurally related allergen glutaraldehyde (GA) was tested. BALB/c mice were exposed by inhalation to 6 or 18ppm GA (respiratory LLNA), both generated as a vapor and as an aerosol. Other groups received 0.25% or 2.5% GA on the skin of the ears (skin LLNA). Lymphocyte proliferation and cytokine production were measured in the draining lymph nodes. GA was positive in the skin LLNA and its cytokine profile (IL-4/IFN-γ) skewed towards a Th2-type immune response with increasing dose. Inhalation exposure did not result in increased lymphocyte proliferation or increased cytokine levels, despite comparable tissue damage (irritation) in the skin and respiratory tract. We hypothesize that the highly reactive and hydrophilic GA oligomerizes in the protein-rich mucous layer of the respiratory tract, which impedes sensitization but still facilitates local irritation. Within the context of risk assessment in respiratory allergy, our results stress the importance of prevention of skin--besides inhalation-- exposure to aldehydes like GA. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  4. The respiratory allergen glutaraldehyde in the local lymph node assay: Sensitization by skin exposure, but not by inhalation

    International Nuclear Information System (INIS)

    Triel, Jos J. van; Bree, Bianca W.J. van; Roberts, David W.; Muijser, Hans; Duistermaat, Evert; Woutersen, Ruud A.; Kuper, C. Frieke

    2011-01-01

    Previously, a selection of low molecular weight contact and respiratory allergens had tested positive in both a skin and a respiratory local lymph node assay (LLNA), but formaldehyde was negative for sensitization by inhalation. To investigate whether this was due to intrinsic properties of aldehyde sensitizers, the structurally related allergen glutaraldehyde (GA) was tested. BALB/c mice were exposed by inhalation to 6 or 18 ppm GA (respiratory LLNA), both generated as a vapor and as an aerosol. Other groups received 0.25% or 2.5% GA on the skin of the ears (skin LLNA). Lymphocyte proliferation and cytokine production were measured in the draining lymph nodes. GA was positive in the skin LLNA and its cytokine profile (IL-4/IFN-γ) skewed towards a Th2-type immune response with increasing dose. Inhalation exposure did not result in increased lymphocyte proliferation or increased cytokine levels, despite comparable tissue damage (irritation) in the skin and respiratory tract. We hypothesize that the highly reactive and hydrophilic GA oligomerizes in the protein-rich mucous layer of the respiratory tract, which impedes sensitization but still facilitates local irritation. Within the context of risk assessment in respiratory allergy, our results stress the importance of prevention of skin - besides inhalation - exposure to aldehydes like GA.

  5. Skin fibroblasts from a D-deletion type retinoblastoma patient are abnormally X-ray sensitive

    International Nuclear Information System (INIS)

    Weichselbaum, R.R.; Nove, J.; Little, J.B.

    1977-01-01

    Retinoblastoma is a rare malignant eye tumour that appears either spontaneously or in genetically predisposed persons. The latter group is composed of persons who inherit the tumour with a dominant mode of transmission (the familial type) and those who have a deletion in the long arm of chromosome 13 referred to as the D-deletion type. When this deletion is present it is observed in many somatic cells and is often associated with structural defects. Survivors of the genetic forms of retinoblastoma have an increased risk of the development of cancers at other sites. A single genetic locus is unlikely to predispose many somatic cells to tumour formation unless a fundamental molecular defect, possibly related to DNA repair, is present. In order to investigate this hypothesis a study was made of the in vitro X-ray sensitivity of skin fibroblasts derived from three retinoblastoma patients, comprising a pair of twins with the familial type accompanied by no gross chromosome abnormalities, and a patient with the D-deletion type. It was found that fibroblasts derived from the D-deletion patient were significantly more radiosensitive than those from the other two patients. X-ray survival curves are shown. It is concluded that skin fibroblasts derived from a patient with the D-deletion variant of retinoblastoma are abnormally radiosensitive. Future investigations may indicate a specific defect in molecular repair of DNA that will explain the predisposition of these patients to the development of other tumours. (U.K.)

  6. Quantification of Eosinophilic Granule Protein Deposition in Biopsies of Inflammatory Skin Diseases by Automated Image Analysis of Highly Sensitive Immunostaining

    Directory of Open Access Journals (Sweden)

    Peter Kiehl

    1999-01-01

    Full Text Available Eosinophilic granulocytes are major effector cells in inflammation. Extracellular deposition of toxic eosinophilic granule proteins (EGPs, but not the presence of intact eosinophils, is crucial for their functional effect in situ. As even recent morphometric approaches to quantify the involvement of eosinophils in inflammation have been only based on cell counting, we developed a new method for the cell‐independent quantification of EGPs by image analysis of immunostaining. Highly sensitive, automated immunohistochemistry was done on paraffin sections of inflammatory skin diseases with 4 different primary antibodies against EGPs. Image analysis of immunostaining was performed by colour translation, linear combination and automated thresholding. Using strictly standardized protocols, the assay was proven to be specific and accurate concerning segmentation in 8916 fields of 520 sections, well reproducible in repeated measurements and reliable over 16 weeks observation time. The method may be valuable for the cell‐independent segmentation of immunostaining in other applications as well.

  7. Mechano-sensitive nociceptors are required to detect heat pain thresholds and cowhage itch in human skin.

    Science.gov (United States)

    Weinkauf, B; Dusch, M; van der Ham, J; Benrath, J; Ringkamp, M; Schmelz, M; Rukwied, R

    2016-02-01

    Mechano-sensitive and mechano-insensitive C-nociceptors in human skin differ in receptive field sizes and electrical excitation thresholds, but their distinct functional roles are yet unclear. After blocking the lateral femoral cutaneous nerve (NCFL) in eight healthy male subjects (3-mL Naropin(®) 1%), we mapped the skin innervation territory being anaesthetic to mechanical pin prick but sensitive to painful transcutaneous electrical stimuli. Such 'differentially anaesthetic zones' indicated that the functional innervation with mechano-sensitive nociceptors was absent but the innervation with mechano-insensitive nociceptors remained intact. In these areas, we explored heat pain thresholds, low pH-induced pain, cowhage- and histamine-induced itch, and axon reflex flare. In differentially anaesthetic skin, heat pain thresholds were above the cut-off of 50°C (non-anaesthetized skin 47 ± 0.4°C). Pain ratings to 30 μL pH 4 injections were reduced compared to non-anaesthetized skin (48 ± 9 vs. 79 ± 6 VAS; p pain. The mechano-sensitive nociceptors are crucial for cowhage-induced itch and for the assessment of heat pain thresholds. © 2015 European Pain Federation - EFIC®

  8. Dye-sensitized solar cells based on purple corn sensitizers

    International Nuclear Information System (INIS)

    Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

    2016-01-01

    Graphical abstract: - Highlights: • Extract from husk, cob and silk of purple corn was used as a photosensitizer in DSSC. • Effect of solvents i.e. acetone, ethanol and DI water on DSSC efficiency was studied. • The highest efficiency of 1.06% was obtained in DSSC based on acetone extraction. - Abstract: Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  9. Dye-sensitized solar cells based on purple corn sensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Phinjaturus, Kawin [Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Maiaugree, Wasan [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Suriharn, Bhalang [Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002 (Thailand); Pimanpaeng, Samuk; Amornkitbamrung, Vittaya [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Integrated Nanotechnology Research Center (INRC), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Swatsitang, Ekaphan, E-mail: ekaphan@kku.ac.th [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Integrated Nanotechnology Research Center (INRC), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Nanotec-KKU Center of Excellence on Advanced Nanomaterials for Energy Production and Storage, Khon Kaen 40002 (Thailand)

    2016-09-01

    Graphical abstract: - Highlights: • Extract from husk, cob and silk of purple corn was used as a photosensitizer in DSSC. • Effect of solvents i.e. acetone, ethanol and DI water on DSSC efficiency was studied. • The highest efficiency of 1.06% was obtained in DSSC based on acetone extraction. - Abstract: Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  10. Nanowire FET Based Neural Element for Robotic Tactile Sensing Skin

    Directory of Open Access Journals (Sweden)

    William Taube Navaraj

    2017-09-01

    Full Text Available This paper presents novel Neural Nanowire Field Effect Transistors (υ-NWFETs based hardware-implementable neural network (HNN approach for tactile data processing in electronic skin (e-skin. The viability of Si nanowires (NWs as the active material for υ-NWFETs in HNN is explored through modeling and demonstrated by fabricating the first device. Using υ-NWFETs to realize HNNs is an interesting approach as by printing NWs on large area flexible substrates it will be possible to develop a bendable tactile skin with distributed neural elements (for local data processing, as in biological skin in the backplane. The modeling and simulation of υ-NWFET based devices show that the overlapping areas between individual gates and the floating gate determines the initial synaptic weights of the neural network - thus validating the working of υ-NWFETs as the building block for HNN. The simulation has been further extended to υ-NWFET based circuits and neuronal computation system and this has been validated by interfacing it with a transparent tactile skin prototype (comprising of 6 × 6 ITO based capacitive tactile sensors array integrated on the palm of a 3D printed robotic hand. In this regard, a tactile data coding system is presented to detect touch gesture and the direction of touch. Following these simulation studies, a four-gated υ-NWFET is fabricated with Pt/Ti metal stack for gates, source and drain, Ni floating gate, and Al2O3 high-k dielectric layer. The current-voltage characteristics of fabricated υ-NWFET devices confirm the dependence of turn-off voltages on the (synaptic weight of each gate. The presented υ-NWFET approach is promising for a neuro-robotic tactile sensory system with distributed computing as well as numerous futuristic applications such as prosthetics, and electroceuticals.

  11. An improvement of LLNA:DA to assess the skin sensitization potential of chemicals.

    Science.gov (United States)

    Zhang, Hongwei; Shi, Ying; Wang, Chao; Zhao, Kangfeng; Zhang, Shaoping; Wei, Lan; Dong, Li; Gu, Wen; Xu, Yongjun; Ruan, Hongjie; Zhi, Hong; Yang, Xiaoyan

    2017-01-01

    We developed a modified local lymph node assay based on ATP (LLNA:DA), termed the Two-Stage LLNA:DA, to further reduce the animal numbers in the identification of sensitizers. In the Two-Stage LLNA:DA procedure, 13 chemicals ranging from non-sensitizers to extreme sensitizers were selected. The first stage used reduced LLNA:DA (rLLNA:DA) to screen out sensitive chemicals. The second stage used LLNA:DA based on OECD 442 (A) to classify those potential sensitizers screened out in the first stage. In the first stage, the SIs of the methyl methacrylate, salicylic acid, methyl salicylate, ethyl salicylate, isopropanol and propanediol were below 1.8 and need not to be tested in the second step. Others continued to be tested by LLNA:DA. In the second stage, sodium lauryl sulphate and xylene were classified as weak sensitizers. a-hexyl cinnamic aldehyde and eugenol were moderate sensitizers. Benzalkonium chloride and glyoxal were strong sensitizers, and phthalic anhydride was an extreme sensitizer. The 9/9, 11/12, 10/11, and 8/13 (positive or negative only) categories of the Two-Stage LLNA:DA were consistent with those from the other methods (LLNA, LLNA:DA, GPMT/BT and HMT/HPTA), suggesting that Two-Stage LLNA:DA have a high coincidence rate with reported data. In conclusion, The Two-Stage LLNA:DA is in line with the "3R" rules, and can be a modification of LLNA:DA but needs more study.

  12. Assessment of phototoxicity, skin irritation, and sensitization potential of polystyrene and TiO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yoon-Hee; Jeong, Sang Hoon; Yi, Sang Min; Choi, Byeong Hyeok; Son, Sang Wook [Laboratory of Cell Signaling and Nanomedicine, Department of Dermatology and Division of Brain Korea 21 Project for Biomedical Science, Korea University College of Medicine, Seoul (Korea, Republic of); Kim, Yu-Ri; Kim, In-Kyoung; Kim, Meyoung-Kon [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of)

    2011-07-06

    The human skin equivalent model (HSEM) is well known as an attractive alternative model for evaluation of dermal toxicity. However, only limited data are available on the usefulness of an HSEM for nanotoxicity testing. This study was designed to investigate cutaneous toxicity of polystyrene and TiO{sub 2} nanoparticles using cultured keratinocytes, an HSEM, and an animal model. In addition, we also evaluated the skin sensitization potential of nanoparticles using a local lymph node assay with incorporation of BrdU. Findings from the present study indicate that polystyrene and TiO{sub 2} nanoparticles do not induce phototoxicity, acute cutaneous irritation, or skin sensitization. Results from evaluation of the HSEMs correspond well with those from animal models. Our findings suggest that the HSEM might be a useful alternative model for evaluation of dermal nanotoxicity.

  13. Seasonal dynamics of chemokine receptors and CD62L in subjects with asymptomatic skin sensitization to birch and grass pollen

    DEFF Research Database (Denmark)

    Assing, K; Bødtger, Uffe; Poulsen, L K

    2006-01-01

    BACKGROUND: Asymptomatic skin sensitization (AS) has been shown to be a risk factor for respiratory allergic disease. CCR4, CXCR1 and CD62L have all been assigned a role in the immunopathogenesis of allergy. Memory T-cell expression of CCR4, CXCR1 and CD62L has not hitherto been investigated in s...

  14. Risk factors associated with sensitive skin and potential role of lifestyle habits: a cross-sectional study

    NARCIS (Netherlands)

    Falcone, D.; Richters, R.J.H.; Uzunbajakava, N.E.; Erp, P.E.J. van; Kerkhof, P.C.M. van de

    2017-01-01

    Sensitive skin (SS) is a widespread condition, but still not completely understood. To identify risk factors that increase the likelihood of SS, 258 women aged between 20 and 65 years old and resident in the Netherlands were surveyed by questionnaire, which included questions on sociodemographic

  15. The respiratory allergen glutaraldehyde in the local lymph node assay: Sensitization by skin exposure, but not by inhalation

    NARCIS (Netherlands)

    Triel, J.J. van; Bree, B.W.J. van; Roberts, D.W.; Muijser, H.; Duistermaat, E.; Woutersen, R.A.; Kuper, C.F.

    2011-01-01

    Previously, a selection of low molecular weight contact and respiratory allergens had tested positive in both a skin and a respiratory local lymph node assay (LLNA), but formaldehyde was negative for sensitization by inhalation. To investigate whether this was due to intrinsic properties of aldehyde

  16. Cows Milk-Dependent Exercise- Induced Anaphylaxis under the Condition of a Premenstrual or Ovulatory Phase Following Skin Sensitization

    Directory of Open Access Journals (Sweden)

    Toshinori Bito

    2008-01-01

    Discussion: The symptoms against cows milk began when she took baths with bath salts containing cows milk as its main ingredient for one year at the age 15 years. Sensitization to cows milk through eczematous skin is indicated from this history. Hormonal change during a premenstrual or ovulatory phase is also an important factor for the development of FDEIA in this case.

  17. Estimating material parameters of a structurally based constitutive relation for skin mechanics

    KAUST Repository

    Jor, Jessica W. Y.; Nash, Martyn P.; Nielsen, Poul M. F.; Hunter, Peter J.

    2010-01-01

    This paper presents a structurally based modeling framework to characterize the structure-function relation in skin tissues, based upon biaxial tensile experiments performed in vitro on porcine skin. Equi-axial deformations were imposed

  18. Suitability of macrophage inflammatory protein-1beta production by THP-1 cells in differentiating skin sensitizers from irritant chemicals.

    Science.gov (United States)

    Lim, Yeon-Mi; Moon, Seong-Joon; An, Su-Sun; Lee, Soo-Jin; Kim, Seo-Young; Chang, Ih-Seop; Park, Kui-Lea; Kim, Hyoung-Ah; Heo, Yong

    2008-04-01

    Worldwide restrictions in animal use for research have driven efforts to develop alternative methods. The study aimed to test the efficacy of the macrophage inflammatory protein-1beta (MIP-1beta) assay for testing chemicals' skin-sensitizing capacity. The assay was performed using 9 chemicals judged to be sensitizing and 7 non-sensitizing by the standard in vivo assays. THP-1 cells were cultured in the presence or absence of 4 doses, 0.01x, 0.1x, 0.5x, or 1x IC(50) (50% inhibitory concentration for THP-1 cell proliferation) of these chemicals for 24 hr, and the MIP-1beta level in the supernatants was determined. Skin sensitization by the test chemicals was determined by MIP-1beta production rates. The MIP-1beta production rate was expressed as the relative increase in MIP-1beta production in response to chemical treatment compared with vehicle treatment. When the threshold MIP-1beta production rate used was 100% or 105% of dimethyl sulfoxide, all the sensitizing chemicals tested (dinitrochlorobenzene, hexyl cinnamic aldehyde, eugenol, hydroquinone, dinitrofluorobenzene, benzocaine, nickel, chromium, and 5-chloro-2-methyl-4-isothiazolin-3-one) were positive, and all the non-sensitizing chemicals (methyl salicylate, benzalkonium chloride, lactic acid, isopropanol, and salicylic acid), with the exception of sodium lauryl sulfate, were negative for MIP-1beta production. These results indicate that MIP-1beta could be a biomarker for classification of chemicals as sensitizers or non-sensitizers.

  19. Three-Dimensional In Vitro Skin and Skin Cancer Models Based on Human Fibroblast-Derived Matrix.

    Science.gov (United States)

    Berning, Manuel; Prätzel-Wunder, Silke; Bickenbach, Jackie R; Boukamp, Petra

    2015-09-01

    Three-dimensional in vitro skin and skin cancer models help to dissect epidermal-dermal and tumor-stroma interactions. In the model presented here, normal human dermal fibroblasts isolated from adult skin self-assembled into dermal equivalents with their specific fibroblast-derived matrix (fdmDE) over 4 weeks. The fdmDE represented a complex human extracellular matrix that was stabilized by its own heterogeneous collagen fiber meshwork, largely resembling a human dermal in vivo architecture. Complemented with normal human epidermal keratinocytes, the skin equivalent (fdmSE) thereof favored the establishment of a well-stratified and differentiated epidermis and importantly allowed epidermal regeneration in vitro for at least 24 weeks. Moreover, the fdmDE could be used to study the features of cutaneous skin cancer. Complementing fdmDE with HaCaT cells in different stages of malignancy or tumor-derived cutaneous squamous cell carcinoma cell lines, the resulting skin cancer equivalents (fdmSCEs) recapitulated the respective degree of tumorigenicity. In addition, the fdmSCE invasion phenotypes correlated with their individual degree of tissue organization, disturbance in basement membrane organization, and presence of matrix metalloproteinases. Together, fdmDE-based models are well suited for long-term regeneration of normal human epidermis and, as they recapitulate tumor-specific growth, differentiation, and invasion profiles of cutaneous skin cancer cells, also provide an excellent human in vitro skin cancer model.

  20. Evaluation of a novel very high sun-protection-factor moisturizer in adults with rosacea-prone sensitive skin.

    Science.gov (United States)

    Grivet-Seyve, Mathieu; Santoro, Francine; Lachmann, Nadège

    2017-01-01

    Rosacea-prone sensitive skin requires high sun-protection factor (SPF) moisturizers. This study evaluated Daylong Extreme SPF 50+ lotion, a novel cream containing five ultraviolet filters, two emollients, and three skin conditioners. This was an open-label, single-center study. On day 1, before treatment, subjects answered a questionnaire on their skin conditions and sunscreen habits, and both subjects and dermatologist evaluated skin status. Subjects applied the product once daily in the morning to the face for 21 days, and after approximately 3-5 minutes they assessed tolerability and short-term cosmetic acceptability in a questionnaire and daily diary. On day 22, the dermatologist and subjects evaluated skin status for long-term tolerance and cosmetic acceptability. The study enrolled 44 individuals (mean age 58.8 years, 91% female). At baseline, most subjects (39 of 44) showed erythema, and ~30% showed dryness and scaling. Dermatologists noted four cases of pustules and one case of papules. After 21 days' treatment with the product, the dermatologist reported significantly less erythema, dryness and scaling, three cases of pustules and two cases of papules. At baseline, ~75% of subjects noted a feeling of dryness, >50% reported tension, and nearly 25% reported tickling. After using the product for 21 days, subjects reported significantly less tension, dryness, and tickling. Some subjects noted itching and burning before and after using the product. One subject noted papules during treatment. Most subjects said that the product was pleasant, did not irritate the skin or cause stinging/burning, was easy to apply, quickly absorbed, and nongreasy, improved skin moisturization, helped prevent sun-provoked facial redness, did not worsen rosacea, and was easily incorporated into their skincare regimen. Half would switch to the product, and 80% of subjects would buy and recommend the product. The product was well tolerated in rosacea-prone subjects, producing objective

  1. Characterising the variations in ethnic skin colours: a new calibrated data base for human skin.

    Science.gov (United States)

    Xiao, K; Yates, J M; Zardawi, F; Sueeprasan, S; Liao, N; Gill, L; Li, C; Wuerger, S

    2017-02-01

    Accurate skin colour measurements are important for numerous medical applications including the diagnosis and treatment of cutaneous disorders and the provision of maxillofacial soft tissue prostheses. In this study, we obtained accurate skin colour measurements from four different ethnic groups (Caucasian, Chinese, Kurdish, Thai) and at four different body locations (Forehead, cheek, inner arm, back of hand) with a view of establishing a new skin colour database for medical and cosmetic applications. Skin colours are measured using a spectrophotometer and converted to a device-independent standard colour appearance space (CIELAB) where skin colour is expressed as values along the three dimensions: Lightness L*, Redness a* and Yellowness b*. Skin colour differences and variation are then evaluated as a function of ethnicity and body location. We report three main results: (1) When plotted in a standard colour appearance space (CIELAB), skin colour distributions for the four ethnic groups overlap significantly, although there are systematic mean differences. Between ethnicities, the most significant skin colour differences occur along the yellowness dimension, with Thai skin exhibiting the highest yellowness (b*) value and Caucasian skin the lowest value. Facial redness (a*) is invariant across the four ethnic groups. (2) Between different body locations, there are significant variations in redness (a*), with the forehead showing the highest redness value and the inner arm the lowest. (3) The colour gamut is smallest in the Chinese sample and largest in the Caucasian sample, with the Chinese gamut lying entirely the Caucasian gamut. Similarly, the largest variability in skin tones is found in the Caucasian group, and the smallest in the Chinese group. Broadly speaking, skin colour variation can be explained by two main factors: individual differences in lightness and yellowness are mostly due to ethnicity, whereas differences in redness are primarily due to

  2. Water-Based Pressure-Sensitive Paints

    Science.gov (United States)

    Jordan, Jeffrey D.; Watkins, A. Neal; Oglesby, Donald M.; Ingram, JoAnne L.

    2006-01-01

    Water-based pressure-sensitive paints (PSPs) have been invented as alternatives to conventional organic-solvent-based pressure-sensitive paints, which are used primarily for indicating distributions of air pressure on wind-tunnel models. Typically, PSPs are sprayed onto aerodynamic models after they have been mounted in wind tunnels. When conventional organic-solvent-based PSPs are used, this practice creates a problem of removing toxic fumes from inside the wind tunnels. The use of water-based PSPs eliminates this problem. The waterbased PSPs offer high performance as pressure indicators, plus all the advantages of common water-based paints (low toxicity, low concentrations of volatile organic compounds, and easy cleanup by use of water).

  3. Pyridoxylamine reactivity kinetics as an amine based nucleophile for screening electrophilic dermal sensitizers

    Science.gov (United States)

    Chipinda, Itai; Mbiya, Wilbes; Adigun, Risikat Ajibola; Morakinyo, Moshood K.; Law, Brandon F.; Simoyi, Reuben H.; Siegel, Paul D.

    2015-01-01

    Chemical allergens bind directly, or after metabolic or abiotic activation, to endogenous proteins to become allergenic. Assessment of this initial binding has been suggested as a target for development of assays to screen chemicals for their allergenic potential. Recently we reported a nitrobenzenethiol (NBT) based method for screening thiol reactive skin sensitizers, however, amine selective sensitizers are not detected by this assay. In the present study we describe an amine (pyridoxylamine (PDA)) based kinetic assay to complement the NBT assay for identification of amine-selective and non-selective skin sensitizers. UV-Vis spectrophotometry and fluorescence were used to measure PDA reactivity for 57 chemicals including anhydrides, aldehydes, and quinones where reaction rates ranged from 116 to 6.2 × 10−6 M−1 s−1 for extreme to weak sensitizers, respectively. No reactivity towards PDA was observed with the thiol-selective sensitizers, non-sensitizers and prohaptens. The PDA rate constants correlated significantly with their respective murine local lymph node assay (LLNA) threshold EC3 values (R2 = 0.76). The use of PDA serves as a simple, inexpensive amine based method that shows promise as a preliminary screening tool for electrophilic, amine-selective skin sensitizers. PMID:24333919

  4. The impact of vehicle on the relative potency of skin-sensitizing chemicals in the local lymph node assay.

    Science.gov (United States)

    Jowsey, Ian R; Clapp, Catherine J; Safford, Bob; Gibbons, Ben T; Basketter, David A

    2008-01-01

    The identification and characterization of chemicals that possess skin-sensitizing potential are typically performed using predictive tests. However, human exposure to skin-sensitizing chemicals often occurs via a matrix (vehicle) that differs from that used in these tests. It is thus important to account for the potential impact of vehicle differences when undertaking quantitative risk assessment for skin sensitization. This is achieved through the application of a specific sensitization assessment factor (SAF), scaled between 1 and 10, when identifying an acceptable exposure level. The objective of the analysis described herein is to determine the impact of vehicle differences on local lymph node assay (LLNA) EC3 values (concentrations of test chemical required to provoke a 3-fold increase in lymph node cell proliferation). Initially, the inherent variability of the LLNA was investigated by examining the reproducibility of EC3 values for 14 chemicals that have been tested more than once in the same vehicle (4:1 acetone:olive oil, AOO). This analysis reveals that the variability in EC3 value for these chemicals following multiple assessments is LLNA using at least 2 of 15 different vehicles. These data demonstrate that often the variability in EC3 values observed for a given chemical in different vehicles is no greater than the 5-fold inherent variability observed when assessing a chemical in the same vehicle on multiple occasions. However, there are examples where EC3 values for a chemical differ by a factor of more than 10 between different vehicles. These observations were often associated with an apparent underestimation of potency (higher EC3 values) with predominantly aqueous vehicles or propylene glycol. These data underscore the need to consider vehicle effects in the context of skin-sensitization risk assessments.

  5. Evaluation of a novel very high sun-protection-factor moisturizer in adults with rosacea-prone sensitive skin

    Directory of Open Access Journals (Sweden)

    Grivet-Seyve M

    2017-06-01

    Full Text Available Mathieu Grivet-Seyve,1 Francine Santoro,2 Nadège Lachmann2 1Galderma Research and Development, Sophia Antipolis, France; 2Galderma Research and Development, Egerkingen, Switzerland Background/objective: Rosacea-prone sensitive skin requires high sun-protection factor (SPF moisturizers. This study evaluated Daylong Extreme SPF 50+ lotion, a novel cream containing five ultraviolet filters, two emollients, and three skin conditioners.Subjects and methods: This was an open-label, single-center study. On day 1, before treatment, subjects answered a questionnaire on their skin conditions and sunscreen habits, and both subjects and dermatologist evaluated skin status. Subjects applied the product once daily in the morning to the face for 21 days, and after approximately 3–5 minutes they assessed tolerability and short-term cosmetic acceptability in a questionnaire and daily diary. On day 22, the dermatologist and subjects evaluated skin status for long-term tolerance and cosmetic acceptability.Results: The study enrolled 44 individuals (mean age 58.8 years, 91% female. At baseline, most subjects (39 of 44 showed erythema, and ~30% showed dryness and scaling. Dermatologists noted four cases of pustules and one case of papules. After 21 days’ treatment with the product, the dermatologist reported significantly less erythema, dryness and scaling, three cases of pustules and two cases of papules. At baseline, ~75% of subjects noted a feeling of dryness, >50% reported tension, and nearly 25% reported tickling. After using the product for 21 days, subjects reported significantly less tension, dryness, and tickling. Some subjects noted itching and burning before and after using the product. One subject noted papules during treatment. Most subjects said that the product was pleasant, did not irritate the skin or cause stinging/burning, was easy to apply, quickly absorbed, and nongreasy, improved skin moisturization, helped prevent sun-provoked facial

  6. High sensitivity MOSFET-based neutron dosimetry

    International Nuclear Information System (INIS)

    Fragopoulou, M.; Konstantakos, V.; Zamani, M.; Siskos, S.; Laopoulos, T.; Sarrabayrouse, G.

    2010-01-01

    A new dosemeter based on a metal-oxide-semiconductor field effect transistor sensitive to both neutrons and gamma radiation was manufactured at LAAS-CNRS Laboratory, Toulouse, France. In order to be used for neutron dosimetry, a thin film of lithium fluoride was deposited on the surface of the gate of the device. The characteristics of the dosemeter, such as the dependence of its response to neutron dose and dose rate, were investigated. The studied dosemeter was very sensitive to gamma rays compared to other dosemeters proposed in the literature. Its response in thermal neutrons was found to be much higher than in fast neutrons and gamma rays.

  7. Blebbistatin, a myosin II inhibitor, suppresses Ca(2+)-induced and "sensitized"-contraction of skinned tracheal muscles from guinea pig.

    Science.gov (United States)

    Yumoto, Masatoshi; Watanabe, Masaru

    2013-01-01

    Blebbistatin, a potent inhibitor of myosin II, has inhibiting effects on Ca(2+)-induced contraction and contractile filament organization without affecting the Ca(2+)-sensitivity to the force and phosphorylation level of myosin regulatory light chain (MLC20) in skinned (cell membrane permeabilized) taenia cecum from the guinea pig (Watanabe et al., Am J Physiol Cell Physiol. 2010; 298: C1118-26). In the present study, we investigated blebbistatin effects on the contractile force of skinned tracheal muscle, in which myosin filaments organization is more labile than that in the taenia cecum. Blebbistatin at 10 μM or higher suppressed Ca(2+)-induced tension development at any given Ca(2+) concentration, but had little effects on the Ca(2+)- induced myosin light chain phosphorylation. Also blebbistatin at 10 μM and higher significantly suppressed GTP-γS-induced "sensitized" force development. Since the force inhibiting effects of blebbistatin on the skinned trachea were much stronger than those in skinned taenia cecum, blebbistatin might directly affect myosin filaments organization.

  8. Advanced Materials for Health Monitoring with Skin-Based Wearable Devices.

    Science.gov (United States)

    Jin, Han; Abu-Raya, Yasmin Shibli; Haick, Hossam

    2017-06-01

    Skin-based wearable devices have a great potential that could result in a revolutionary approach to health monitoring and diagnosing disease. With continued innovation and intensive attention to the materials and fabrication technologies, development of these healthcare devices is progressively encouraged. This article gives a concise, although admittedly non-exhaustive, didactic review of some of the main concepts and approaches related to recent advances and developments in the scope of skin-based wearable devices (e.g. temperature, strain, biomarker-analysis werable devices, etc.), with an emphasis on emerging materials and fabrication techniques in the relevant fields. To give a comprehensive statement, part of the review presents and discusses different aspects of these advanced materials, such as the sensitivity, biocompatibility and durability as well as the major approaches proposed for enhancing their chemical and physical properties. A complementary section of the review linking these advanced materials with wearable device technologies is particularly specified. Some of the strong and weak points in development of each wearable material/device are highlighted and criticized. Several ideas regarding further improvement of skin-based wearable devices are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Estimating material parameters of a structurally based constitutive relation for skin mechanics

    KAUST Repository

    Jor, Jessica W. Y.

    2010-11-25

    This paper presents a structurally based modeling framework to characterize the structure-function relation in skin tissues, based upon biaxial tensile experiments performed in vitro on porcine skin. Equi-axial deformations were imposed by stretching circular skin specimens uniformly along twelve directions, and the resultant loads at the membrane attachment points were measured. Displacement fields at each deformation step were tracked using an image 2D cross-correlation technique. A modeling framework was developed to simulate the experiments, whereby measured forces were applied to finite element models that were created to represent the geometry and structure of the tissue samples. Parameters of a structurally based constitutive relation were then identified using nonlinear optimization. Results showed that the ground matrix stiffness ranged from 5 to 32 kPa, fiber orientation mean from 2 to 13. from the torso midline, fiber undulation mean from 1.04 to 1.34 and collagen fiber stiffness from 48 to 366 MPa. It was concluded that the objective function was highly sensitive to the mean orientation and that a priori information about fiber orientation mean was important for the reliable identification of constitutive parameters. © Springer-Verlag 2010.

  10. Sensitivity of the electric dipole polarizability to the neutron skin thickness in {sup 208}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Roca-Maza, X.; Agrawal, B. K.; Colo, G.; Nazarewicz, W.; Paar, N.; Piekarewicz, J.; Reinhard, P.-G.; Vretenar, D. [INFN, sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Saha Institute of Nuclear Physics, Kolkata 700064 (India); Dipartimento di Fisica, Universita degli Studi di Milano and INFN, Sezione di Milano, 20133 Milano (Italy); Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States) and Institute of Theoretical Physics, University of Warsaw, Hoza 69, PL-00-681 Warsaw (Poland); Physics Department, Faculty of Science, University of Zagreb, Zagreb (Croatia); Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Institut fuer Theoretische Physik II, Universitaet Erlangen-Nuernberg, Staudtstrasse 7, D-91058 Erlangen (Germany); Physics Department, Faculty of Science, University of Zagreb, Zagreb (Croatia)

    2012-10-20

    The static dipole polarizability, {alpha}{sub D}, in {sup 208}Pb has been recently measured with highresolution via proton inelastic scattering at the Research Center for Nuclear Physics (RCNP) [1]. This observable is thought to be intimately connected with the neutron skin thickness, r{sub skin}, of the same nucleus and, more fundamentally, it is believed to be associated with the density dependence of the nuclear symmetry energy. The impact of r{sub skin} on {alpha}{sub D} in {sup 208}Pb is investigated and discussed on the basis of a large and representative set of relativistic and non-relativistic nuclear energy density functionals (EDF) [2].

  11. Innovative Natural Ingredients-Based Multiple Emulsions: The Effect on Human Skin Moisture, Sebum Content, Pore Size and Pigmentation

    Directory of Open Access Journals (Sweden)

    Ugne Cizauskaite

    2018-06-01

    Full Text Available The increased interest in natural cosmetics has resulted in a higher market demand for preservative-free products based on herbal ingredients. An innovative W/O/W type emulsions containing herbal extracts were prepared directly; its cation form was induced by an ethanolic rosemary extract and stabilized using weak herbal gels. Due to the wide phytochemical composition of herbal extracts and the presence of alcohol in the emulsion system, which can cause skin irritation, sensitization or dryness when applied topically, the safety of the investigated drug delivery system is necessary. The aim of our study was to estimate the potential of W/O/W emulsions based on natural ingredients for skin irritation and phototoxicity using reconstructed 3D epidermis models in vitro and to evaluate in vivo its effect on human skin moisture, sebum content and pigmentation by biomedical examination using a dermatoscopic camera and corneometer. According to the results obtained after in vitro cell viability test the investigated emulsion was neither irritant nor phototoxic to human skin keratinocytes. W/O/W emulsion did not cause skin dryness in vivo, despite the fact that it contained ethanol. We can conclude that the emulsion is safe for use as a leave-on product due to the positive effect on human skin characteristics or as a semisolid pharmaceutical base where active compounds could be encapsulated.

  12. Emu oil-based lotion effects on neonatal skin barrier during transition from intrauterine to extrauterine life

    Directory of Open Access Journals (Sweden)

    Zanardo V

    2017-08-01

    Full Text Available Vincenzo Zanardo,1 David Giarrizzo,2 Francesca Volpe,1 Lara Giliberti,1 Gianluca Straface1 1Division of Perinatal Medicine, Policlinico Abano Terme, Abano Terme, 2CALANTHA Physiology of Lactation Laboratory, Padua, Italy Abstract: Both appropriate hydration and skin surface pH are fundamental in preventing baby skin barrier damage during transition from intrauterine to extrauterine life. However, effects of topical moisturizers on neonatal stratum corneum temperature, pH, hydration, and elasticity have not been scientifically evaluated in vivo. We checked 31 full-term breastfeeding neonates by non-invasive bioengineering method, which is able to evaluate the basal skin barrier (left heel, and assessed at 6±1 hours after birth, and at 1 and 24 hours after emu oil-based topical treatment. The basal skin barrier of right heel (no oil exposure of each newborn was considered as control. We found that a single application of an emu oil-based lotion was effective in improving heel stratum corneum hydration, which increases both skin pH and elasticity without any effect on temperature. Further studies are needed to confirm long-term beneficial effects of this treatment in a very sensitive patient population. Keywords: skin barrier, neonate, emu oil-based lotion, topical treatment

  13. Skin-Inspired Hierarchical Polymer Architectures with Gradient Stiffness for Spacer-Free, Ultrathin, and Highly Sensitive Triboelectric Sensors.

    Science.gov (United States)

    Ha, Minjeong; Lim, Seongdong; Cho, Soowon; Lee, Youngoh; Na, Sangyun; Baig, Chunggi; Ko, Hyunhyub

    2018-04-24

    The gradient stiffness between stiff epidermis and soft dermis with interlocked microridge structures in human skin induces effective stress transmission to underlying mechanoreceptors for enhanced tactile sensing. Inspired by skin structure and function, we fabricate hierarchical nanoporous and interlocked microridge structured polymers with gradient stiffness for spacer-free, ultrathin, and highly sensitive triboelectric sensors (TESs). The skin-inspired hierarchical polymers with gradient elastic modulus enhance the compressibility and contact areal differences due to effective transmission of the external stress from stiff to soft layers, resulting in highly sensitive TESs capable of detecting human vital signs and voice. In addition, the microridges in the interlocked polymers provide an effective variation of gap distance between interlocked layers without using the bulk spacer and thus facilitate the ultrathin and flexible design of TESs that could be worn on the body and detect a variety of pressing, bending, and twisting motions even in humid and underwater environments. Our TESs exhibit the highest power density (46.7 μW/cm 2 ), pressure (0.55 V/kPa), and bending (∼0.1 V/°) sensitivities ever reported on flexible TESs. The proposed design of hierarchical polymer architectures for the flexible and wearable TESs can find numerous applications in next-generation wearable electronics.

  14. Correlation between sensitivity to acid hydrolysis and skin-core differentiation in viscose rayon

    NARCIS (Netherlands)

    Hermans, P.H.; Heikens, D.

    1952-01-01

    It is shown that the extent of hydrolysis in a given set of conditions is qualitatively related to the thickness of the rayon skin. This interpretation is preferable to that of relating extent of hydrolysis to crystalline amorphous ratio.

  15. [Effect of ionizing radiation and other factors on the thermal sensitivity of mouse skin].

    Science.gov (United States)

    Kurpeshev, O K; Konopliannikov, A G

    1987-03-01

    A study was made of the effect of various agents on skin injury by hyperthermia in experiments on noninbred albino mice. The effects of heating were assessed by the frequency of skin necrosis development. The results of the study showed that irradiation of the skin (30 Gy) before heating did not influence its thermosensitivity whereas heating 45-180 days after irradiation proved more effective. Ethanol, metronidazole, thyrocalcitonin and actinomycin D decreased skin thermosensitivity, and cyclohexamide, serotonin, hyperglycemia and applying a tourniquet increased it. The DMF value for actinomycin D depended on the temperature of heating. One should distinguish between true modification of tissue thermosensitivity (determined by cellular factors) and indirect modification (associated with change in volumetric circulation rate).

  16. Polarization-Sensitive Hyperspectral Imaging in vivo: A Multimode Dermoscope for Skin Analysis

    Science.gov (United States)

    Vasefi, Fartash; MacKinnon, Nicholas; Saager, Rolf B.; Durkin, Anthony J.; Chave, Robert; Lindsley, Erik H.; Farkas, Daniel L.

    2014-05-01

    Attempts to understand the changes in the structure and physiology of human skin abnormalities by non-invasive optical imaging are aided by spectroscopic methods that quantify, at the molecular level, variations in tissue oxygenation and melanin distribution. However, current commercial and research systems to map hemoglobin and melanin do not correlate well with pathology for pigmented lesions or darker skin. We developed a multimode dermoscope that combines polarization and hyperspectral imaging with an efficient analytical model to map the distribution of specific skin bio-molecules. This corrects for the melanin-hemoglobin misestimation common to other systems, without resorting to complex and computationally intensive tissue optical models. For this system's proof of concept, human skin measurements on melanocytic nevus, vitiligo, and venous occlusion conditions were performed in volunteers. The resulting molecular distribution maps matched physiological and anatomical expectations, confirming a technologic approach that can be applied to next generation dermoscopes and having biological plausibility that is likely to appeal to dermatologists.

  17. Skin-Inspired Multifunctional Autonomic-Intrinsic Conductive Self-Healing Hydrogels with Pressure Sensitivity, Stretchability, and 3D Printability.

    Science.gov (United States)

    Darabi, Mohammad Ali; Khosrozadeh, Ali; Mbeleck, Rene; Liu, Yuqing; Chang, Qiang; Jiang, Junzi; Cai, Jun; Wang, Quan; Luo, Gaoxing; Xing, Malcolm

    2017-08-01

    The advent of conductive self-healing (CSH) hydrogels, a class of novel materials mimicking human skin, may change the trajectory of the industrial process because of their potential applications in soft robots, biomimetic prostheses, and health-monitoring systems. Here, the development of a mechanically and electrically self-healing hydrogel based on physically and chemically cross-linked networks is reported. The autonomous intrinsic self-healing of the hydrogel is attained through dynamic ionic interactions between carboxylic groups of poly(acrylic acid) and ferric ions. A covalent cross-linking is used to support the mechanical structure of the hydrogel. Establishing a fair balance between the chemical and physical cross-linking networks together with the conductive nanostructure of polypyrrole networks leads to a double network hydrogel with bulk conductivity, mechanical and electrical self-healing properties (100% mechanical recovery in 2 min), ultrastretchability (1500%), and pressure sensitivity. The practical potential of CSH hydrogels is further revealed by their application in human motion detection and their 3D-printing performance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. In vitro activation of the neuro-transduction mechanism in sensitive organotypic human skin model.

    Science.gov (United States)

    Martorina, Francesca; Casale, Costantino; Urciuolo, Francesco; Netti, Paolo A; Imparato, Giorgia

    2017-01-01

    Recent advances in tissue engineering have encouraged researchers to endeavor the production of fully functional three-dimensional (3D) thick human tissues in vitro. Here, we report the fabrication of a fully innervated human skin tissue in vitro that recapitulates and replicates skin sensory function. Previous attempts to innervate in vitro 3D skin models did not demonstrate an effective functionality of the nerve network. In our approach, we initially engineer functional human skin tissue based on fibroblast-generated dermis and differentiated epidermis; then, we promote rat dorsal root ganglion (DRG) neurons axon ingrowth in the de-novo developed tissue. Neurofilaments network infiltrates the entire native dermis extracellular matrix (ECM), as demonstrated by immunofluorescence and second harmonic generation (SHG) imaging. To prove sensing functionality of the tissue, we use topical applications of capsaicin, an agonist of transient receptor protein-vanilloid 1 (TRPV1) channel, and quantify calcium currents resulting from variations of Ca ++ concentration in DRG neurons innervating our model. Calcium currents generation demonstrates functional cross-talking between dermis and epidermis compartments. Moreover, through a computational fluid dynamic (CFD) analysis, we set fluid dynamic conditions for a non-planar skin equivalent growth, as proof of potential application in creating skin grafts tailored on-demand for in vivo wound shape. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Tactile surface classification for limbed robots using a pressure sensitive robot skin

    International Nuclear Information System (INIS)

    Shill, Jacob J; Collins Jr, Emmanuel G; Coyle, Eric; Clark, Jonathan

    2015-01-01

    This paper describes an approach to terrain identification based on pressure images generated through direct surface contact using a robot skin constructed around a high-resolution pressure sensing array. Terrain signatures for classification are formulated from the magnitude frequency responses of the pressure images. The initial experimental results for statically obtained images show that the approach yields classification accuracies >98%. The methodology is extended to accommodate the dynamic pressure images anticipated when a robot is walking or running. Experiments with a one-legged hopping robot yield similar identification accuracies ≈99%. In addition, the accuracies are independent with respect to changing robot dynamics (i.e., when using different leg gaits). The paper further shows that the high-resolution capabilities of the sensor enables similarly textured surfaces to be distinguished. A correcting filter is developed to accommodate for failures or faults that inevitably occur within the sensing array with continued use. Experimental results show using the correcting filter can extend the effective operational lifespan of a high-resolution sensing array over 6x in the presence of sensor damage. The results presented suggest this methodology can be extended to autonomous field robots, providing a robot with crucial information about the environment that can be used to aid stable and efficient mobility over rough and varying terrains. (paper)

  20. Fabrication of strain gauge based sensors for tactile skins

    Science.gov (United States)

    Baptist, Joshua R.; Zhang, Ruoshi; Wei, Danming; Saadatzi, Mohammad Nasser; Popa, Dan O.

    2017-05-01

    Fabricating cost effective, reliable and functional sensors for electronic skins has been a challenging undertaking for the last several decades. Application of such skins include haptic interfaces, robotic manipulation, and physical human-robot interaction. Much of our recent work has focused on producing compliant sensors that can be easily formed around objects to sense normal, tension, or shear forces. Our past designs have involved the use of flexible sensors and interconnects fabricated on Kapton substrates, and piezoresistive inks that are 3D printed using Electro Hydro Dynamic (EHD) jetting onto interdigitated electrode (IDE) structures. However, EHD print heads require a specialized nozzle and the application of a high-voltage electric field; for which, tuning process parameters can be difficult based on the choice of inks and substrates. Therefore, in this paper we explore sensor fabrication techniques using a novel wet lift-off photolithographic technique for patterning the base polymer piezoresistive material, specifically Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) or PEDOT:PSS. Fabricated sensors are electrically and thermally characterized, and temperaturecompensated designs are proposed and validated. Packaging techniques for sensors in polymer encapsulants are proposed and demonstrated to produce a tactile interface device for a robot.

  1. Reconstructing Carotenoid-Based and Structural Coloration in Fossil Skin.

    Science.gov (United States)

    McNamara, Maria E; Orr, Patrick J; Kearns, Stuart L; Alcalá, Luis; Anadón, Pere; Peñalver, Enrique

    2016-04-25

    Evidence of original coloration in fossils provides insights into the visual communication strategies used by ancient animals and the functional evolution of coloration over time [1-7]. Hitherto, all reconstructions of the colors of reptile integument and the plumage of fossil birds and feathered dinosaurs have been of melanin-based coloration [1-6]. Extant animals also use other mechanisms for producing color [8], but these have not been identified in fossils. Here we report the first examples of carotenoid-based coloration in the fossil record, and of structural coloration in fossil integument. The fossil skin, from a 10 million-year-old colubrid snake from the Late Miocene Libros Lagerstätte (Teruel, Spain) [9, 10], preserves dermal pigment cells (chromatophores)-xanthophores, iridophores, and melanophores-in calcium phosphate. Comparison with chromatophore abundance and position in extant reptiles [11-15] indicates that the fossil snake was pale-colored in ventral regions; dorsal and lateral regions were green with brown-black and yellow-green transverse blotches. Such coloration most likely functioned in substrate matching and intraspecific signaling. Skin replicated in authigenic minerals is not uncommon in exceptionally preserved fossils [16, 17], and dermal pigment cells generate coloration in numerous reptile, amphibian, and fish taxa today [18]. Our discovery thus represents a new means by which to reconstruct the original coloration of exceptionally preserved fossil vertebrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. The local lymph node assay and skin sensitization: a cut-down screen to reduce animal requirements?

    Science.gov (United States)

    Kimber, Ian; Dearman, Rebecca J; Betts, Catherine J; Gerberick, G Frank; Ryan, Cindy A; Kern, Petra S; Patlewicz, Grace Y; Basketter, David A

    2006-04-01

    The local lymph node assay (LLNA), an alternative approach to skin-sensitizing testing, has made a significant contribution to animal welfare by permitting a reduction and refinement of animal use. Although there is clearly an aspiration to eliminate the use of animals in such tests, it is appropriate also to consider other opportunities for refinement and reduction of animal use. We have therefore explored the use of a modified version of the LLNA for screening purposes when there is a need to evaluate the sensitizing activity of a large number of chemicals, as will be the case under the auspices of registration, evaluation and authorization of chemicals (REACH). Using an existing LLNA database of 211 chemicals, we have examined whether a cut-down assay comprising a single high-dose group and a concurrent vehicle control would provide a realistic approach for screening chemicals for sensitizing potential. The analyses reported here suggest this is the case. We speculate that the animal welfare benefits may be enhanced further by reducing the number of animals per experimental group. However, a detailed evaluation will be necessary to provide reassurance that a reduction in group size would provide adequate sensitivity across a range of skin sensitization potencies.

  3. Dye-sensitized solar cells based on purple corn sensitizers

    Science.gov (United States)

    Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

    2016-09-01

    Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  4. Optical indicators based on environment sensitive fluorophors

    Energy Technology Data Exchange (ETDEWEB)

    Shakhsher, Z.M.; Seitz, W.R. (Univ. of New Hampshire, Durham, NC (USA))

    1990-01-01

    The authors are interested in the development of optical indicators based on environment sensitive fluorophors. The fluorophor is immobilized on a solid substrate. Interaction with analyte modifies the fluorophor environment, leading to a shift in the distribution of emission wavelengths. Because the indicator is based on spectral shift, it is possible to relate analyte concentration to a ratio of intensities at two different wavelengths. This parameter is insensitive to instrumental drift and slow loss of indicator. Two indicator systems have been investigated. Both involve dansyl derivation, i.e., derivatives of 5-dimethylamino-1-naphthalene sulfonic acid.

  5. Water-Based Pressure Sensitive Paint

    Science.gov (United States)

    Oglesby, Donald M.; Ingram, JoAnne L.; Jordan, Jeffrey D.; Watkins, A. Neal; Leighty, Bradley D.

    2004-01-01

    Preparation and performance of a water-based pressure sensitive paint (PSP) is described. A water emulsion of an oxygen permeable polymer and a platinum porphyrin type luminescent compound were dispersed in a water matrix to produce a PSP that performs well without the use of volatile, toxic solvents. The primary advantages of this PSP are reduced contamination of wind tunnels in which it is used, lower health risk to its users, and easier cleanup and disposal. This also represents a cost reduction by eliminating the need for elaborate ventilation and user protection during application. The water-based PSP described has all the characteristics associated with water-based paints (low toxicity, very low volatile organic chemicals, and easy water cleanup) but also has high performance as a global pressure sensor for PSP measurements in wind tunnels. The use of a water-based PSP virtually eliminates the toxic fumes associated with the application of PSPs to a model in wind tunnels.

  6. Comparison of sensitivity of quantiferon-tb gold test and tuberculin skin test in active pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Khalil, K.F.; Ambreen, A.; Butt, T.

    2013-01-01

    Objective: To compare the sensitivity of tuberculin skin test (TST) and quantiFERON-TB gold test (QFT-G) in active pulmonary tuberculosis. Study Design: Analytical study. Place and Duration of Study: Department of Pulmonology, Fauji Foundation Hospital, Rawalpindi, from July 2011 to January 2012. Methodology: QuantiFERON-TB gold test (QFT-G) was evaluated and compared it with tuberculin skin test (TST) in 50 cases of active pulmonary tuberculosis, in whom tuberculous infection was suspected on clinical, radiological and microbiological grounds. Sensitivity was determined against positive growth for Mycobacterium tuberculosis. Results: Out of 50 cases, 43 were females and 7 were males. The mean age was 41.84 A+- 19.03 years. Sensitivity of QFT-G was 80% while that of TST was 28%. Conclusion: QFT-G has much higher sensitivity than TST for active pulmonary tuberculosis. It is unaffected by prior BCG administration and prior exposure to atypical mycobacteria. A positive QFT-G result can be an adjunct to diagnosis in patients having clinical and radiological data compatible with pulmonary tuberculosis. (author)

  7. Integrating non-animal test information into an adaptive testing strategy - skin sensitization proof of concept case.

    Science.gov (United States)

    Jaworska, Joanna; Harol, Artsiom; Kern, Petra S; Gerberick, G Frank

    2011-01-01

    There is an urgent need to develop data integration and testing strategy frameworks allowing interpretation of results from animal alternative test batteries. To this end, we developed a Bayesian Network Integrated Testing Strategy (BN ITS) with the goal to estimate skin sensitization hazard as a test case of previously developed concepts (Jaworska et al., 2010). The BN ITS combines in silico, in chemico, and in vitro data related to skin penetration, peptide reactivity, and dendritic cell activation, and guides testing strategy by Value of Information (VoI). The approach offers novel insights into testing strategies: there is no one best testing strategy, but the optimal sequence of tests depends on information at hand, and is chemical-specific. Thus, a single generic set of tests as a replacement strategy is unlikely to be most effective. BN ITS offers the possibility of evaluating the impact of generating additional data on the target information uncertainty reduction before testing is commenced.

  8. Local lymph node assay (LLNA): comparison of different protocols by testing skin-sensitizing epoxy resin system components.

    Science.gov (United States)

    Gamer, Armin O; Nies, Eberhard; Vohr, Hans-Werner

    2008-12-01

    Thirteen epoxy resin system components were tested in the LLNA with regard to their sensitizing potency. Lymph node stimulation was quantified not only by measuring the incorporation of [3H]-thymidine into the ear lymph nodes but also the counts of cells recovered from these organs. Equivalent figures were obtained with both endpoints used for the evaluation of lymph node cell proliferation if the reference stimulation indices were adjusted. When dissolved in acetone, all test substances showed skin-sensitizing potential, mainly on the boundary between "strong" and "moderate" according to common potency evaluation schemes. Replacing acetone with acetone/olive oil (4:1) as a vehicle for four selected test items, resulted in considerably lower estimated concentrations for sensitization induction. The challenges in comparing the results obtained by different LLNA variations are discussed.

  9. A link between skin and airways regarding sensitivity to fragrance products?

    DEFF Research Database (Denmark)

    Elberling, J; Linneberg, A; Mosbech, Holger Fausbøll

    2004-01-01

    Exposure to volatile fragrances is commonplace and may be related to various eye and airway symptoms. Skin exposure to fragrances is known to cause perfume contact allergy and eczema, but it is unknown whether eye or airway symptoms elicited by fragrance products are associated with contact allergy...

  10. In vivo observation of age-related structural changes of dermal collagen in human facial skin using collagen-sensitive second harmonic generation microscope equipped with 1250-nm mode-locked Cr:Forsterite laser

    Science.gov (United States)

    Yasui, Takeshi; Yonetsu, Makoto; Tanaka, Ryosuke; Tanaka, Yuji; Fukushima, Shu-ichiro; Yamashita, Toyonobu; Ogura, Yuki; Hirao, Tetsuji; Murota, Hiroyuki; Araki, Tsutomu

    2013-03-01

    In vivo visualization of human skin aging is demonstrated using a Cr:Forsterite (Cr:F) laser-based, collagen-sensitive second harmonic generation (SHG) microscope. The deep penetration into human skin, as well as the specific sensitivity to collagen molecules, achieved by this microscope enables us to clearly visualize age-related structural changes of collagen fiber in the reticular dermis. Here we investigated intrinsic aging and/or photoaging in the male facial skin. Young subjects show dense distributions of thin collagen fibers, whereas elderly subjects show coarse distributions of thick collagen fibers. Furthermore, a comparison of SHG images between young and elderly subjects with and without a recent life history of excessive sun exposure show that a combination of photoaging with intrinsic aging significantly accelerates skin aging. We also perform image analysis based on two-dimensional Fourier transformation of the SHG images and extracted an aging parameter for human skin. The in vivo collagen-sensitive SHG microscope will be a powerful tool in fields such as cosmeceutical sciences and anti-aging dermatology.

  11. Grass pollen symptoms interfere with the recollection of birch pollen symptoms - a prospective study of suspected, asymptomatic skin sensitization

    DEFF Research Database (Denmark)

    Assing, K; Bødtger, Uffe; Poulsen, L K

    2007-01-01

    of seasonal allergic symptoms and prospective seasonal symptom registration among subjects with AS. METHODS: On the basis of a population survey, autumn 2002, including skin prick tests (positive if > or =3 mm) and a screening questionnaire, 87 subjects with AS to birch and/or grass pollen, birch and/or grass...... days. RESULTS: Eleven AS subjects (birch: n = 10) subsequently developed allergic symptoms, yet nine admitted, at follow up, to have had symptoms before inclusion, or even denied pollen-related symptoms despite a significant diary. Compared with AS subjects sensitized to grass pollen, AS subjects...

  12. All Organic Polymers Based Morphing Skin with Controllable Surface Texture

    KAUST Repository

    Favero Bolson, Natanael

    2018-05-01

    Smart skins are integrating an increasing number of functionalities in order to improve the interaction between the systems they equip and their ambient environment. Here we have developed an electromechanical soft actuator with controlled surface texture due to applied thermal gradient via electrical voltage. The device was fabricated and integrated with optimized process parameters for a prepared heater element [doped PEDOT: PSS (poly-(3, 4 ethylenedioxythiophene): poly (styrene sulfonic acid))], a soft actuator (Ecoflex 00-50/ethanol) and overall packaging case [PDMS (polydimethylsiloxane)]. To study a potential application of the proposed smart skin, we analyze the fluid drag reduction in a texture controlled water flow unit. As a result, we obtained a reduction of approximately 14% in the skin drag friction coefficient during the actuation. We conclude that the proposed soft actuator device is a preferred option for a texture-controlled skin that reduces the skin drag friction coefficient.

  13. A constriction resistance model of conjugated polymer based piezoresistive sensors for electronic skin applications.

    Science.gov (United States)

    Khalili, N; Naguib, H E; Kwon, R H

    2016-05-14

    Human intervention can be replaced through the development of tools resulting from utilization of sensing devices possessing a wide range of applications including humanoid robots or remote and minimally invasive surgeries. Similar to the five human senses, sensors interface with their surroundings to stimulate a suitable response or action. The sense of touch which arises in human skin is among the most challenging senses to emulate due to its ultra high sensitivity. This has brought forth novel challenging issues to consider in the field of biomimetic robotics. In this work, using a multiphase reaction, a polypyrrole (PPy) based hydrogel is developed as a resistive type pressure sensor with an intrinsically elastic microstructure stemming from three dimensional hollow spheres. It is shown that the electrical conductivity of the fabricated PPy based piezoresistive sensors is enhanced as a result of adding conductive fillers and therefore, endowing the sensors with a higher sensitivity. A semi-analytical constriction resistance based model accounting for the real contact area between the PPy hydrogel sensors and the electrode along with the dependency of the contact resistance change on the applied load is developed. The model is then solved using a Monte Carlo technique and its corresponding sensitivity is obtained. Comparing the results with their experimental counterparts, the proposed modeling methodology offers a good tracking ability.

  14. Quantitative evaluation methods of skin condition based on texture feature parameters

    Directory of Open Access Journals (Sweden)

    Hui Pang

    2017-03-01

    Full Text Available In order to quantitatively evaluate the improvement of the skin condition after using skin care products and beauty, a quantitative evaluation method for skin surface state and texture is presented, which is convenient, fast and non-destructive. Human skin images were collected by image sensors. Firstly, the median filter of the 3 × 3 window is used and then the location of the hairy pixels on the skin is accurately detected according to the gray mean value and color information. The bilinear interpolation is used to modify the gray value of the hairy pixels in order to eliminate the negative effect of noise and tiny hairs on the texture. After the above pretreatment, the gray level co-occurrence matrix (GLCM is calculated. On the basis of this, the four characteristic parameters, including the second moment, contrast, entropy and correlation, and their mean value are calculated at 45 ° intervals. The quantitative evaluation model of skin texture based on GLCM is established, which can calculate the comprehensive parameters of skin condition. Experiments show that using this method evaluates the skin condition, both based on biochemical indicators of skin evaluation methods in line, but also fully consistent with the human visual experience. This method overcomes the shortcomings of the biochemical evaluation method of skin damage and long waiting time, also the subjectivity and fuzziness of the visual evaluation, which achieves the non-destructive, rapid and quantitative evaluation of skin condition. It can be used for health assessment or classification of the skin condition, also can quantitatively evaluate the subtle improvement of skin condition after using skin care products or stage beauty.

  15. Quantitative evaluation methods of skin condition based on texture feature parameters.

    Science.gov (United States)

    Pang, Hui; Chen, Tianhua; Wang, Xiaoyi; Chang, Zhineng; Shao, Siqi; Zhao, Jing

    2017-03-01

    In order to quantitatively evaluate the improvement of the skin condition after using skin care products and beauty, a quantitative evaluation method for skin surface state and texture is presented, which is convenient, fast and non-destructive. Human skin images were collected by image sensors. Firstly, the median filter of the 3 × 3 window is used and then the location of the hairy pixels on the skin is accurately detected according to the gray mean value and color information. The bilinear interpolation is used to modify the gray value of the hairy pixels in order to eliminate the negative effect of noise and tiny hairs on the texture. After the above pretreatment, the gray level co-occurrence matrix (GLCM) is calculated. On the basis of this, the four characteristic parameters, including the second moment, contrast, entropy and correlation, and their mean value are calculated at 45 ° intervals. The quantitative evaluation model of skin texture based on GLCM is established, which can calculate the comprehensive parameters of skin condition. Experiments show that using this method evaluates the skin condition, both based on biochemical indicators of skin evaluation methods in line, but also fully consistent with the human visual experience. This method overcomes the shortcomings of the biochemical evaluation method of skin damage and long waiting time, also the subjectivity and fuzziness of the visual evaluation, which achieves the non-destructive, rapid and quantitative evaluation of skin condition. It can be used for health assessment or classification of the skin condition, also can quantitatively evaluate the subtle improvement of skin condition after using skin care products or stage beauty.

  16. IgE Sensitization Patterns to Commonly Consumed Foods Determined by Skin Prick Test in Korean Adults.

    Science.gov (United States)

    Kim, Sung Ryeol; Park, Hye Jung; Park, Kyung Hee; Lee, Jae-Hyun; Park, Jung-Won

    2016-08-01

    Offending food allergens can vary with regional preferences in food consumption. In this study, we analysed sensitization rates to commonly consumed foods in Korean adults suspected of having food allergy. One hundred and thirty four subjects underwent a skin prick test (SPT) with 55 food allergens, of which 13 were made by our laboratory and the rest were commercially purchased. Of the 134 patients, 73 (54.5%) were sensitized to one or more food allergens. Sensitization to chrysalis was detected most frequently, at a rate of 25.4%. Sensitization rates to other food allergens were as follows: maize grain (13.4%), shrimp (11.9%), almond (11.1%), wheat flour (8.2%), lobster (8.2%), buckwheat (8.2%), mackerel (5.2%), pollack (5.2%), halibut (4.5%), peanut (4.5%), anchovy (4.4%), squid (3.7%), saury (3.0%), common eel (3.0%), yellow corvina (3.0%), hairtail (2.2%), octopus (2.2%), and others. In addition to well-known food allergens, sensitivity to mackerel, chrysalis, pollack, and halibut, which are popular foods in Korea, was observed at high rates in Korean adults. We suggest that the SPT panel for food allergy in Korea should include these allergens.

  17. IgE Sensitization Patterns to Commonly Consumed Foods Determined by Skin Prick Test in Korean Adults

    Science.gov (United States)

    2016-01-01

    Offending food allergens can vary with regional preferences in food consumption. In this study, we analysed sensitization rates to commonly consumed foods in Korean adults suspected of having food allergy. One hundred and thirty four subjects underwent a skin prick test (SPT) with 55 food allergens, of which 13 were made by our laboratory and the rest were commercially purchased. Of the 134 patients, 73 (54.5%) were sensitized to one or more food allergens. Sensitization to chrysalis was detected most frequently, at a rate of 25.4%. Sensitization rates to other food allergens were as follows: maize grain (13.4%), shrimp (11.9%), almond (11.1%), wheat flour (8.2%), lobster (8.2%), buckwheat (8.2%), mackerel (5.2%), pollack (5.2%), halibut (4.5%), peanut (4.5%), anchovy (4.4%), squid (3.7%), saury (3.0%), common eel (3.0%), yellow corvina (3.0%), hairtail (2.2%), octopus (2.2%), and others. In addition to well-known food allergens, sensitivity to mackerel, chrysalis, pollack, and halibut, which are popular foods in Korea, was observed at high rates in Korean adults. We suggest that the SPT panel for food allergy in Korea should include these allergens. PMID:27478328

  18. Skin tightening.

    Science.gov (United States)

    Woolery-Lloyd, Heather; Kammer, Jenna N

    2011-01-01

    Skin tightening describes the treatment of skin laxity via radiofrequency (RF), ultrasound, or light-based devices. Skin laxity on the face is manifested by progressive loss of skin elasticity, loosening of the connective tissue framework, and deepening of skin folds. This results in prominence of submandibular and submental tissues. Genetic factors (chronological aging) and extrinsic factors (ultraviolet radiation) both contribute to skin laxity. There are many RF, ultrasound, and light-based devices directed at treating skin laxity. All of these devices target and heat the dermis to induce collagen contraction. Heating of the dermis causes collagen denaturation and immediate collagen contraction in addition to long-term collagen remodeling. Via RF, light, or ultrasound, these skin tightening devices deliver heat to the dermis to create new collagen and induce skin tightening. This chapter will provide an overview of the various skin tightening devices. Copyright © 2011 S. Karger AG, Basel.

  19. Evaluation of human skin tests for potential dermal irritant and contact sensitizing products: a position paper

    NARCIS (Netherlands)

    Loveren H van; Jong WH de; Garssen J; LPI

    1998-01-01

    Prediction of human cutaneous irritation and sensitization in view of hazard identification has primarily relied on the use of laboratory animals. Such studies in laboratory animals have been very instrumental in the detection of potential contact sensitizing agents. There are however many

  20. Skin fluorescence model based on the Monte Carlo technique

    Science.gov (United States)

    Churmakov, Dmitry Y.; Meglinski, Igor V.; Piletsky, Sergey A.; Greenhalgh, Douglas A.

    2003-10-01

    The novel Monte Carlo technique of simulation of spatial fluorescence distribution within the human skin is presented. The computational model of skin takes into account spatial distribution of fluorophores following the collagen fibers packing, whereas in epidermis and stratum corneum the distribution of fluorophores assumed to be homogeneous. The results of simulation suggest that distribution of auto-fluorescence is significantly suppressed in the NIR spectral region, while fluorescence of sensor layer embedded in epidermis is localized at the adjusted depth. The model is also able to simulate the skin fluorescence spectra.

  1. Natural evolution of skin-test sensitivity in patients with IgE-mediated hypersensitivity to cephalosporins.

    Science.gov (United States)

    Romano, A; Gaeta, F; Valluzzi, R L; Zaffiro, A; Caruso, C; Quaratino, D

    2014-06-01

    There are studies demonstrating that skin-test sensitivity to penicillins can decrease over time and that allergic patients may lose sensitivity if the responsible compounds are avoided. With regard to subjects with IgE-mediated hypersensitivity to cephalosporins, however, such studies are lacking. We evaluated prospectively in a 5-year follow-up 72 cephalosporin-allergic patients. After the first evaluation, patients were classified into two groups according to their patterns of allergologic-test positivity: to both penicillins and cephalosporins (group A), or only to cephalosporins (group B). Skin tests and serum-specific IgE assays were repeated 1 year later and, in case of persistent positivity, 3 and 5 years after the first allergologic examination. Seven (43.7%) of the 16 subjects of group A and 38 (67.8%) of the 56 patients of group B became negative; one was lost to follow-up. Patients of group B became negative sooner and more frequently than group A subjects. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Touch sensitive electrorheological fluid based tactile display

    Science.gov (United States)

    Liu, Yanju; Davidson, Rob; Taylor, Paul

    2005-12-01

    A tactile display is programmable device whose controlled surface is intended to be investigated by human touch. It has a great number of potential applications in the field of virtual reality and elsewhere. In this research, a 5 × 5 tactile display array including electrorheological (ER) fluid has been developed and investigated. Force responses of the tactile display array have been measured while a probe was moved across the upper surface. The purpose of this was to simulate the action of touch performed by human finger. Experimental results show that the sensed surface information could be controlled effectively by adjusting the voltage activation pattern imposed on the tactels. The performance of the tactile display is durable and repeatable. The touch sensitivity of this ER fluid based tactile display array has also been investigated in this research. The results show that it is possible to sense the touching force normal to the display's surface by monitoring the change of current passing through the ER fluid. These encouraging results are helpful for constructing a new type of tactile display based on ER fluid which can act as both sensor and actuator at the same time.

  3. Mobile phone based mini-spectrometer for rapid screening of skin cancer

    Science.gov (United States)

    Das, Anshuman; Swedish, Tristan; Wahi, Akshat; Moufarrej, Mira; Noland, Marie; Gurry, Thomas; Aranda-Michel, Edgar; Aksel, Deniz; Wagh, Sneha; Sadashivaiah, Vijay; Zhang, Xu; Raskar, Ramesh

    2015-06-01

    We demonstrate a highly sensitive mobile phone based spectrometer that has potential to detect cancerous skin lesions in a rapid, non-invasive manner. Earlier reports of low cost spectrometers utilize the camera of the mobile phone to image the field after moving through a diffraction grating. These approaches are inherently limited by the closed nature of mobile phone image sensors and built in optical elements. The system presented uses a novel integrated grating and sensor that is compact, accurate and calibrated. Resolutions of about 10 nm can be achieved. Additionally, UV and visible LED excitation sources are built into the device. Data collection and analysis is simplified using the wireless interfaces and logical control on the smart phone. Furthermore, by utilizing an external sensor, the mobile phone camera can be used in conjunction with spectral measurements. We are exploring ways to use this device to measure endogenous fluorescence of skin in order to distinguish cancerous from non-cancerous lesions with a mobile phone based dermatoscope.

  4. All Organic Polymers Based Morphing Skin with Controllable Surface Texture

    KAUST Repository

    Favero Bolson, Natanael

    2018-01-01

    Smart skins are integrating an increasing number of functionalities in order to improve the interaction between the systems they equip and their ambient environment. Here we have developed an electromechanical soft actuator with controlled surface

  5. Anchoring molecular mechanisms to the adverse outcome pathway for skin sensitization: Analysis of existing data

    NARCIS (Netherlands)

    Veen, J.W. van der; Soeteman-Hernández, L.G.; Ezendam, J.; Stierum, R.; Kuper, F.C.; Loveren, H. van

    2014-01-01

    Allergic contact dermatitis (ACD) is a hypersensitivity immune response induced by small protein-reactive chemicals. Currently, the murine local lymph node assay (LLNA) provides hazard identification and quantitative estimation of sensitizing potency. Given the complexity of ACD, a single

  6. Minimal erythema dose and minimal melanogenesis dose relate better to objectively measured skin type than to Fitzpatricks skin type

    DEFF Research Database (Denmark)

    Wulf, Hans Christian; Philipsen, Peter A; Ravnbak, Mette H

    2010-01-01

    Fitzpatrick skin type (FST I-IV) is a subjective expression of ultraviolet (UV) sensitivity based on erythema and tanning reactivity after a single exposure. Pigment protection factor (PPF) is an objective measurement of skin sensitivity in all skin types after a single exposure....

  7. Structural and dynamical aspects of skin studied by multiphoton excitation fluorescence microscopy-based methods

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Brewer, Jonathan R.; Bagatolli, Luis

    2013-01-01

    ' parameters. Specifically, by applying these methods, spatially resolved maps of water dipolar relaxation (generalized polarization function using the 6-lauroyl-2-(N,N-dimethylamino)naphthale probe), activity of protons (fluorescence lifetime imaging using a proton sensitive fluorescence probe--2,7-bis-(2......-carboxyethyl)-5-(and-6)-carboxyfluorescein) and diffusion coefficients of distinct fluorescence probes (raster imaging correlation spectroscopy) can be obtained from different regions of the tissue. Comparative studies of different tissue strata, but also between equivalent regions of normal and abnormal......This mini-review reports on applications of particular multiphoton excitation microscopy-based methodologies employed in our laboratory to study skin. These approaches allow in-depth optical sectioning of the tissue, providing spatially resolved information on specific fluorescence probes...

  8. Latest laser and light-based advances for ethnic skin rejuvenation

    Directory of Open Access Journals (Sweden)

    Elsaie Mohamed

    2008-01-01

    Full Text Available Background: Advances in nonablative skin rejuvenation technologies have sparked a renewed interest in the cosmetic treatment of aging skin. More options exist now than ever before to reverse cutaneous changes caused by long-term exposure to sunlight. Although Caucasian skin is more prone to ultraviolet light injury, ethnic skin (typically classified as types IV to VI also exhibits characteristic photoaging changes. Widespread belief that inevitable or irreversible textural changes or dyspigmentation occurs following laser- or light-based treatments, has been challenged in recent years by new classes of devices capable of protecting the epidermis from injury during treatment. Objective: The purpose of this article is to review recent clinical advances in the treatment of photoaging changes in ethnic skin. This article provides a basis for the classification of current advances in nonablative management of ethnic skin.

  9. Assessment of a Protein Cocktail-Based Skin Test for Bovine Tuberculosis in a Double-Blind Field Test in Cattle

    Science.gov (United States)

    Xin, Ting; Jia, Hong; Ding, Jiabo; Li, Pingjun; Yang, Hongjun; Hou, Shaohua; Yuan, Weifeng; Guo, Xiaoyu; Wang, Haichun; Liang, Qianqian; Li, Ming

    2013-01-01

    Bovine tuberculosis (bTB) is a worldwide zoonosis caused mainly by Mycobacterium bovis. The traditional diagnostic method used often is the tuberculin skin test, which uses bovine purified protein derivatives (PPD-B). However, it is difficult to maintain uniformity of PPD-B from batch to batch, and it shares common antigens with nonpathogenic environmental mycobacteria. To overcome these problems, M. bovis-specific antigens that showed good T cell stimulation, such as CFP-10, ESAT-6, Rv3615c, etc., have been used in the skin test, but there have been no large-scale clinical studies on these antigens. In this study, two combinations (CFP-10/ESAT-6/TB10.4 protein cocktail and CFP-10/ESAT-6/Rv3872/MPT63 protein cocktail) were developed and used as stimuli in the skin test. Cattle were double-blind tested to assess the efficiency of the protein cocktail-based skin tests. The results showed that the CFP-10/ESAT-6/TB10.4 protein cocktail-based skin test can differentiate TB-infected cattle from Mycobacterium avium-infected ones and that it shows a high degree of agreement with the traditional tuberculin skin test (κ = 0.8536) and gamma interferon (IFN-γ) release assay (κ = 0.8154). Compared to the tuberculin skin test, the relative sensitivity and relative specificity of the CFP-10/ESAT-6/TB10.4-based skin test were 87% and 97%, respectively., The relative sensitivity and relative specificity of the CFP-10/ESAT-6/TB10.4-based skin test were 93% and 92%, respectively, on comparison with the IFN-γ release assay. The correlation between the increases in skin thickness observed after the inoculation of stimuli was high (PPD-B versus CFP-10/ESAT-6/TB10.4, Spearman r of 0.8435). The correlation between the optical density at 450 nm (OD450) obtained after blood stimulation with PPD-B and the increase in skin thickness observed after inoculation of the CFP-10/ESAT-6/TB10.4 protein cocktail was high (Spearman r = 0.7335). Therefore, the CFP-10/ESAT-6/TB10.4-based skin test

  10. Is Cytox 3522 (10% methylene-bis-thiocyanate) a human skin sensitizer?

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Hamann, K

    1983-01-01

    Methylene-bis-thiocyanate is an antimicrobial agent in Cytox 3522 (American Cyanamid Corporation) and Nalco 206 (Nalco Chemical Company). Both are wide-spectrum industrial biocides. Cytox 3522 showed a strong sensitization potential in guineau pigs using the Guinea Pig Maximization Test and the O...... and the Open Epicutaneous Test procedures. In spite of this, human sensitization has not been reported. This may be explained by several factors such as limited exposure, low-use concentration and a lack of diagnostic patch tests in selected patients....

  11. In situ visualization of glucocerebrosidase in human skin tissue: zymography versus activity-based probe labeling.

    Science.gov (United States)

    van Smeden, Jeroen; Dijkhoff, Irini M; Helder, Richard W J; Al-Khakany, Hanin; Boer, Daphne E C; Schreuder, Anne; Kallemeijn, Wouter W; Absalah, Samira; Overkleeft, Herman S; Aerts, Johannes M F G; Bouwstra, Joke A

    2017-12-01

    Epidermal β-glucocerebrosidase (GBA1), an acid β-glucosidase normally located in lysosomes, converts (glucosyl)ceramides into ceramides, which is crucial to generate an optimal barrier function of the outermost skin layer, the stratum corneum (SC). Here we report on two developed in situ methods to localize active GBA in human epidermis: i ) an optimized zymography method that is less labor intensive and visualizes enzymatic activity with higher resolution than currently reported methods using either substrate 4-methylumbelliferyl-β-D-glucopyranoside or resorufin-β-D-glucopyranoside; and ii ) a novel technique to visualize active GBA1 molecules by their specific labeling with a fluorescent activity-based probe (ABP), MDW941. The latter method pro-ved to be more robust and sensitive, provided higher resolution microscopic images, and was less prone to sample preparation effects. Moreover, in contrast to the zymography substrates that react with various β-glucosidases, MDW941 specifically labeled GBA1. We demonstrate that active GBA1 in the epidermis is primarily located in the extracellular lipid matrix at the interface of the viable epidermis and the lower layers of the SC. With ABP-labeling, we observed reduced GBA1 activity in 3D-cultured skin models when supplemented with the reversible inhibitor, isofagomine, irrespective of GBA expression. This inhibition affected the SC ceramide composition: MS analysis revealed an inhibitor-dependent increase in the glucosylceramide:ceramide ratio. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  12. Skin entrance dose with and without lead apron in digital panoramic radiography for selected sensitive body regions.

    Science.gov (United States)

    Schulze, Ralf Kurt Willy; Cremers, Catrin; Karle, Heiko; de Las Heras Gala, Hugo

    2017-05-01

    The aim of this study was to compare the dose at skin level at five significant anatomical regions for panoramic radiography devices with and without lead apron by means of a highly sensitive dosimeter. A female RANDO-phantom was exposed in five different digital panoramic radiography systems, and the dose at skin level was assessed tenfold for each measurement region by means of a highly sensitive solid-state-dosimeter. The five measurement regions selected were the thyroid, both female breasts, the gonads, and a central region in the back of the phantom. For each panoramic machine, the measurements were performed in two modes: with and without a commercial lead apron specifically designed for panoramic radiography. Reproducibility of the measurements was expressed by absolute differences and the coefficient of variation. Values between shielded and unshielded doses were pooled for each region and compared by means of the paired Wilcoxon tests (p ≤ 0.05). Reproducibility as represented by the mean CV was 22 ± 52 % (median 2.3 %) with larger variations for small dose values. Doses at skin level ranged between 0.00 μGy at the gonads and 85.39 μGy at the unshielded thyroid (mean ± SD 15 ± 24 μGy). Except for the gonads, the dose in all the other regions was significantly lower (p < 0.001) when a lead apron was applied. Unshielded doses were between 1.02-fold (thyroid) and 112-fold (at the right breast) higher than those with lead apron shielding (mean: 14-fold ± 18-fold). Although the doses were entirely very low, we observed a significant increase in dose in the radiation-sensitive female breast region when no lead apron was used. Future discussions on shielding requirements for panoramic radiography should focus on these differences in the light of the linear non-threshold (LNT) theory which is generally adopted in medical imaging.

  13. Mouse allergen-specific immunoglobulin G4 and risk of mouse skin test sensitivity

    NARCIS (Netherlands)

    Matsui, E. C.; Diette, G. B.; Krop, E. J. M.; Aalberse, R. C.; Smith, A. L.; Eggleston, P. A.

    2006-01-01

    High serum levels of cat-specific IgG and IgG4 are associated with protection against allergic sensitization to cat, but whether this association applies to other animal allergens remains unclear. To determine if high levels of mouse-specific IgG and IgG4 are associated with a decreased risk of

  14. 78 FR 68076 - Request for Information on Alternative Skin Sensitization Test Methods and Testing Strategies and...

    Science.gov (United States)

    2013-11-13

    ... Laboratory for Alternatives to Animal Testing (EURL ECVAM), and by the industry organization Cosmetics Europe... products. Pesticides and other marketed chemicals, including cosmetic ingredients, are routinely tested for... sensitization. NICEATM collaboration with industry scientists to develop an open-source Bayesian network as an...

  15. Evaluation of a high-throughput peptide reactivity format assay for assessment of the skin sensitization potential of chemicals

    Directory of Open Access Journals (Sweden)

    Chin Lin eWong

    2016-03-01

    Full Text Available The direct peptide reactivity assay (DPRA is a validated method for in vitro assessment of the skin sensitization potential of chemicals. In the present work, we describe a peptide reactivity assay using 96-well plate format and systematically identified the optimal assay conditions for accurate and reproducible classification of chemicals with known sensitizing capacity. The aim of the research is to ensure that the analytical component of the peptide reactivity assay is robust, accurate and reproducible in accordance with criteria that are used for the validation of bioanalytical methods. Analytical performance was evaluated using quality control samples (QCs; heptapeptides at low, medium and high concentrations and incubation of control chemicals (chemicals with known sensitization capacity, weak, moderate, strong, extreme and non-sensitizers with each of three synthetic heptapeptides, viz Cor1-C420 (Ac-NKKCDLF, cysteine- (Ac-RFAACAA and lysine- (Ac-RFAAKAA containing heptapeptides. The optimal incubation temperature for all three heptapeptides was 25°C. Apparent heptapeptide depletion was affected by vial material composition. Incubation of test chemicals with Cor1-C420, showed that peptide depletion was unchanged in polypropylene vials over 3-days storage in an autosampler but this was not the case for borosilicate glass vials. For cysteine-containing heptapeptide, the concentration was not stable by day 3 post-incubation in borosilicate glass vials. Although the lysine-containing heptapeptide concentration was unchanged in both polypropylene and borosilicate glass vials, the apparent extent of lysine-containing heptapeptide depletion by ethyl acrylate, differed between polypropylene (24.7% and glass (47.3% vials. Additionally, the peptide-chemical complexes for Cor1-C420-cinnamaldehyde and cysteine-containing heptapeptide-2,4-dinitrochlorobenzene were partially reversible during 3-days of autosampler storage. These observations further

  16. Nonablative Fractional Laser Resurfacing in Skin of Color: Evidence-based Review.

    Science.gov (United States)

    Kaushik, Shivani B; Alexis, Andrew F

    2017-06-01

    Background: Nonablative laser resurfacing represents one of the major advances in procedural dermatology over the past decade. However, its use in darker skin types is limited by safety concerns and a relative lack of available data. Aim: To provide evidence-based recommendations for the use of fractional lasers in darker skin types. Evidence review: A broad literature search of PubMed/Medline database was conducted in April 2016 using the term fractional lasers. A free text search of keywords including fractional resurfacing, nonablative lasers, skin type, skin of color, ethnic skin, Fitzpatrick skin type, Asian skin, African Americans, Afro-Caribbean, and Hispanics was also executed. An in-depth review of all the relevant articles fitting the authors' inclusion/exclusion criteria was performed. Thereafter, each study was assigned levels of evidence per the Modified Criteria by Oxford Center of Evidence Based Medicine. A recommendation was made for a specific treatment based on the presence of at least one Level 1 study or more than three Level 2 or 3 studies that had concordant results. Findings: The available evidence strongly suggests that fractional lasers are a favorable treatment option for a variety of dermatological diseases in Fitzpatrick skin phototypes IV to VI. Level 1 evidence was found for the use of fractional lasers for treating acne, striae and skin rejuvenation. Level 2 evidence was found for their use in acne scars, melasma, and surgical/traumatic scars. Conclusion: Fractional resurfacing is a safe and efficacious treatment option for various dermatological disorders in darker skin types; however, there is a paucity of high-quality studies involving skin types V and VI.

  17. Derivative based sensitivity analysis of gamma index

    Directory of Open Access Journals (Sweden)

    Biplab Sarkar

    2015-01-01

    boundary values for evaluating the STTP against the RP. Even though the STTP passed the simple gamma pass criteria, it was found failing at many locations when the derivatives were used as the boundary values. The proposed derivative-based method can identify a noisy curve and can prove to be a useful tool for improving the sensitivity of the gamma index.

  18. Electrical impedance tomography-based sensing skin for quantitative imaging of damage in concrete

    International Nuclear Information System (INIS)

    Hallaji, Milad; Pour-Ghaz, Mohammad; Seppänen, Aku

    2014-01-01

    This paper outlines the development of a large-area sensing skin for damage detection in concrete structures. The developed sensing skin consists of a thin layer of electrically conductive copper paint that is applied to the surface of the concrete. Cracking of the concrete substrate results in the rupture of the sensing skin, decreasing its electrical conductivity locally. The decrease in conductivity is detected with electrical impedance tomography (EIT) imaging. In previous works, electrically based sensing skins have provided only qualitative information on the damage on the substrate surface. In this paper, we study whether quantitative imaging of the damage is possible. We utilize application-specific models and computational methods in the image reconstruction, including a total variation (TV) prior model for the damage and an approximate correction of the modeling errors caused by the inhomogeneity of the painted sensing skin. The developed damage detection method is tested experimentally by applying the sensing skin to polymeric substrates and a reinforced concrete beam under four-point bending. In all test cases, the EIT-based sensing skin provides quantitative information on cracks and/or other damages on the substrate surface: featuring a very low conductivity in the damage locations, and a reliable indication of the lengths and shapes of the cracks. The results strongly support the applicability of the painted EIT-based sensing skin for damage detection in reinforced concrete elements and other substrates. (paper)

  19. An ultra-sensitive biophysical risk assessment of light effect on skin cells.

    Science.gov (United States)

    Bennet, Devasier; Viswanath, Buddolla; Kim, Sanghyo; An, Jeong Ho

    2017-07-18

    The aim of this study was to analyze photo-dynamic and photo-pathology changes of different color light radiations on human adult skin cells. We used a real-time biophysical and biomechanics monitoring system for light-induced cellular changes in an in vitro model to find mechanisms of the initial and continuous degenerative process. Cells were exposed to intermittent, mild and intense (1-180 min) light with On/Off cycles, using blue, green, red and white light. Cellular ultra-structural changes, damages, and ECM impair function were evaluated by up/down-regulation of biophysical, biomechanical and biochemical properties. All cells exposed to different color light radiation showed significant changes in a time-dependent manner. Particularly, cell growth, stiffness, roughness, cytoskeletal integrity and ECM proteins of the human dermal fibroblasts-adult (HDF-a) cells showed highest alteration, followed by human epidermal keratinocytes-adult (HEK-a) cells and human epidermal melanocytes-adult (HEM-a) cells. Such changes might impede the normal cellular functions. Overall, the obtained results identify a new insight that may contribute to premature aging, and causes it to look aged in younger people. Moreover, these results advance our understanding of the different color light-induced degenerative process and help the development of new therapeutic strategies.

  20. Assessing the effectiveness of knowledge-based interventions in increasing skin cancer awareness, knowledge, and protective behaviors in skin of color populations.

    Science.gov (United States)

    Kailas, Ajay; Botwin, Ariel L; Pritchett, Ellen N; Jackson-Richards, Diane; Lewis, Suzanna; Sadhwani, Divya; Desai, Seemal R; Taylor, Susan C

    2017-10-01

    Skin of color (SOC) populations (ie, blacks, Hispanics, Asians) are at a notably higher risk for mortality from skin cancers such as melanoma than white individuals. In this article, we seek to answer the following question: Do knowledge-based interventions increase skin cancer awareness among SOC patients? Following an extensive literature search, a total of 4 articles were analyzed and discussed in this review.

  1. Comparative analysis of skin sensitization potency of acrylates (methyl acrylate, ethyl acrylate, butyl acrylate, and ethylhexyl acrylate) using the local lymph node assay.

    Science.gov (United States)

    Dearman, Rebecca J; Betts, Catherine J; Farr, Craig; McLaughlin, James; Berdasco, Nancy; Wiench, Karin; Kimber, Ian

    2007-10-01

    There are currently available no systematic experimental data on the skin sensitizing properties of acrylates that are of relevance in occupational settings. Limited information from previous guinea-pig tests or from the local lymph node assay (LLNA) is available; however, these data are incomplete and somewhat contradictory. For those reasons, we have examined in the LLNA 4 acrylates: butyl acrylate (BA), ethyl acrylate (EA), methyl acrylate (MA), and ethylhexyl acrylate (EHA). The LLNA data indicated that all 4 compounds have some potential to cause skin sensitization. In addition, the relative potencies of these acrylates were measured by derivation from LLNA dose-response analyses of EC3 values (the effective concentration of chemical required to induce a threefold increase in proliferation of draining lymph node cells compared with control values). On the basis of 1 scheme for the categorization of skin sensitization potency, BA, EA, and MA were each classified as weak sensitizers. Using the same scheme, EHA was considered a moderate sensitizer. However, it must be emphasized that the EC3 value for this chemical of 9.7% is on the borderline between moderate (10%) categories. Thus, the judicious view is that all 4 chemicals possess relatively weak skin sensitizing potential.

  2. Reducing skin cancer risk: an intervention based on protection motivation theory.

    Science.gov (United States)

    McClendon, B T; Prentice-Dunn, S

    2001-05-01

    Caucasian college students who intentionally tanned participated in a brief skin cancer intervention based on protection motivation theory (PMT). This intervention targeted skin appearance and consisted of brief lectures, a comprehensive essay, video clips about a young man who died of melanoma, and short discussions. Compared to a waitlist control group, the intervention group showed increases on PMT variables and intentions at post-test. The waitlist group later received the intervention and showed similar increases. Additionally, all but one PMT variable maintained post-test levels at a one-month follow-up. Photographs taken at post-test and at the one-month follow-up were judged by raters blind to the hypothesis. Seventy-two percent of participants were judged to have lighter skin whereas only 16 percent had darker skin. These results provide additional support for theory-based methods for changing maladaptive attitudes and behaviors associated with skin cancer risk.

  3. Rheological and sensory properties of hydrophilic skin protection gels based on polyacrylates.

    Science.gov (United States)

    Kulawik-Pióro, Agnieszka; Kurpiewska, Joanna; Kułaszka, Agnieszka

    2018-03-01

    With the current increases in occupational skin diseases, literature data attesting the decreasing efficiency of barrier creams with respect to the manufacturer's declarations and legal regulations granting skin protection gels for employees, research is required to analyse and evaluate the recipes used for hydrophilic skin protection gels based on polyacrylates. This study investigated the rheological properties, pH and sensory perception of hydrophilic barrier gels based on polyacrylates. The acrylic acid derivatives used were good thickeners, and helped to form transparent gels of adequate durability. They could be used to create hydrophilic films on the surface of the skin to protect it against hydrophobic substances. A correlation was shown between the results of the rheological properties and the barrier properties of the gels. This confirms the possibility of monitoring the quality of the gels at the stage of recipe development. Polyacrylates are viable for use in industry to produce hydrophilic barrier creams suitable for skin protection.

  4. Going skin deep: A direct comparison of penetration potential of lipid-based nanovesicles on the isolated perfused human skin flap model.

    Science.gov (United States)

    Ternullo, Selenia; de Weerd, Louis; Holsæter, Ann Mari; Flaten, Gøril Eide; Škalko-Basnet, Nataša

    2017-12-01

    Phospholipid-based nanocarriers are attractive drug carriers for improved local skin therapy. In the present study, the recently developed isolated perfused human skin flap (IPHSF) model was used to directly compare the skin penetration enhancing potential of the three commonly used nanocarriers, namely conventional liposomes (CLs), deformable liposomes (DLs) and solid lipid nanoparticles (SLNs). Two fluorescent markers, calcein (hydrophilic) or rhodamine (lipophilic), were incorporated individually in the three nanosystems. The nanocarrier size ranged between 200 and 300nm; the surface charge and entrapment efficiency for both markers were dependent on the lipid composition and the employed surfactant. Both carrier-associated markers could not penetrate the full thickness human skin, confirming their suitability for dermal drug delivery. CLs exhibited higher retention of both markers on the skin surface compared to DLs and SLNs, indicating a depo formation. DLs and SLNs enabled the deeper penetration of the two markers into the skin layers. In vitro and ex vivo skin penetration studies performed on the cellophane membrane and full thickness pig/human skin, respectively, confirmed the findings. In conclusion, efficient dermal drug delivery can be achieved by optimization of a lipid nanocarrier on the suitable skin-mimicking model to assure system's accumulation in the targeted skin layer. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Skin Cancer Treatment

    Science.gov (United States)

    ... Unusual Cancers of Childhood Treatment Genetics of Skin Cancer Skin color and being exposed to sunlight can increase ... is based on the type of nonmelanoma skin cancer or other skin condition diagnosed: Basal cell carcinoma Enlarge Basal cell ...

  6. Stages of Skin Cancer

    Science.gov (United States)

    ... Unusual Cancers of Childhood Treatment Genetics of Skin Cancer Skin color and being exposed to sunlight can increase ... is based on the type of nonmelanoma skin cancer or other skin condition diagnosed: Basal cell carcinoma Enlarge Basal cell ...

  7. Abnormal sensitivity of skin fibroblasts from familial polyposis patients to DNA alkylating agents

    International Nuclear Information System (INIS)

    Barfknecht, T.R.; Little, J.B.

    1982-01-01

    Fibroblast cell strains derived from different patients all afflicted with genetic predisposing to the development of intestinal polyposis and cancer were tested for their sensitivity to the lethal effects of the DNA alkylating agents methylmethanesulfonate (MMS), ethyl methanesulfonate, N-methyl-N'-nitro-N-nitrosoguanidine, and 4-nitroquinoline 1-oxide. The genetic syndromes studied were: (a) adenomatosis of the colon and rectum only, an autosomal dominant trait; (b) Turcot's syndrome, a rare autosomal recessive polyposis syndrome also characterized by central nervous system tumors; and (c) Gardner's syndrome, an autosomal dominant syndrome which, in addition to intestinal polyposis, is also clinically characterized by osteomas and soft tissue tumors. Fibroblasts from a patient with Turcot's syndrome were hypersensitive to MMS, having a D0 value of 0.24 mM (p less than 0.01) versus the normal average D0 of 0.36 mM and a D10 value of 0.95 mM (p less than 0.01) compared with the normal average value of 1.3 mM. Fibroblasts from the Gardner's syndrome proband were moderately sensitive to MMS, ethyl methanesulfonate, and N-methyl-N'-nitro-N-nitrosoguanidine due to significant differences of D10 values of 0.60 mM (p less than 0.01), 15 mM (p less than 0.01), and 4.8 microM (p less than 0.025), respectively, versus the normal average values of 1.3 mM, 28 mM, and 9.4 microM. Fibroblasts from the clinically affected Gardner's syndrome daughter of the proband were significantly more sensitive to MMS treatment, D0 of 0.22 mM (p less than 0.01) versus the normal average D0 of 0.36 mM and a D10 of 0.97 mM (p less than 0.01) versus the normal average. This differential sensitivity to the several DNA alkylating agents suggests that different mechanisms of hypersensitivity to these chemicals may be associated with fibroblasts from the various forms of familial polyposis

  8. Development of an artificial neural network model for risk assessment of skin sensitization using human cell line activation test, direct peptide reactivity assay, KeratinoSens™ and in silico structure alert parameter.

    Science.gov (United States)

    Hirota, Morihiko; Ashikaga, Takao; Kouzuki, Hirokazu

    2018-04-01

    It is important to predict the potential of cosmetic ingredients to cause skin sensitization, and in accordance with the European Union cosmetic directive for the replacement of animal tests, several in vitro tests based on the adverse outcome pathway have been developed for hazard identification, such as the direct peptide reactivity assay, KeratinoSens™ and the human cell line activation test. Here, we describe the development of an artificial neural network (ANN) prediction model for skin sensitization risk assessment based on the integrated testing strategy concept, using direct peptide reactivity assay, KeratinoSens™, human cell line activation test and an in silico or structure alert parameter. We first investigated the relationship between published murine local lymph node assay EC3 values, which represent skin sensitization potency, and in vitro test results using a panel of about 134 chemicals for which all the required data were available. Predictions based on ANN analysis using combinations of parameters from all three in vitro tests showed a good correlation with local lymph node assay EC3 values. However, when the ANN model was applied to a testing set of 28 chemicals that had not been included in the training set, predicted EC3s were overestimated for some chemicals. Incorporation of an additional in silico or structure alert descriptor (obtained with TIMES-M or Toxtree software) in the ANN model improved the results. Our findings suggest that the ANN model based on the integrated testing strategy concept could be useful for evaluating the skin sensitization potential. Copyright © 2017 John Wiley & Sons, Ltd.

  9. An in vitro method for detecting chemical sensitization using human reconstructed skin models and its applicability to cosmetic, pharmaceutical, and medical device safety testing.

    Science.gov (United States)

    McKim, James M; Keller, Donald J; Gorski, Joel R

    2012-12-01

    Chemical sensitization is a serious condition caused by small reactive molecules and is characterized by a delayed type hypersensitivity known as allergic contact dermatitis (ACD). Contact with these molecules via dermal exposure represent a significant concern for chemical manufacturers. Recent legislation in the EU has created the need to develop non-animal alternative methods for many routine safety studies including sensitization. Although most of the alternative research has focused on pure chemicals that possess reasonable solubility properties, it is important for any successful in vitro method to have the ability to test compounds with low aqueous solubility. This is especially true for the medical device industry where device extracts must be prepared in both polar and non-polar vehicles in order to evaluate chemical sensitization. The aim of this research was to demonstrate the functionality and applicability of the human reconstituted skin models (MatTek Epiderm(®) and SkinEthic RHE) as a test system for the evaluation of chemical sensitization and its potential use for medical device testing. In addition, the development of the human 3D skin model should allow the in vitro sensitization assay to be used for finished product testing in the personal care, cosmetics, and pharmaceutical industries. This approach combines solubility, chemical reactivity, cytotoxicity, and activation of the Nrf2/ARE expression pathway to identify and categorize chemical sensitizers. Known chemical sensitizers representing extreme/strong-, moderate-, weak-, and non-sensitizing potency categories were first evaluated in the skin models at six exposure concentrations ranging from 0.1 to 2500 µM for 24 h. The expression of eight Nrf2/ARE, one AhR/XRE and two Nrf1/MRE controlled gene were measured by qRT-PCR. The fold-induction at each exposure concentration was combined with reactivity and cytotoxicity data to determine the sensitization potential. The results demonstrated that

  10. Expression of CD73 slows down migration of skin dendritic cells, affecting the sensitization phase of contact hypersensitivity reactions in mice.

    Science.gov (United States)

    Neuberger, A; Ring, S; Silva-Vilches, C; Schrader, J; Enk, A; Mahnke, K

    2017-09-01

    Application of haptens to the skin induces release of immune stimulatory ATP into the extracellular space. This "danger" signal can be converted to immunosuppressive adenosine (ADO) by the action of the ectonucleotidases CD39 and CD73, expressed by skin and immune cells. Thus, the expression and regulation of CD73 by skin derived cells may have crucial influence on the outcome of contact hypersensitivity (CHS) reactions. To investigate the role of CD73 expression during 2,4,6-trinitrochlorobenzene (TNCB) induced CHS reactions. Wild type (wt) and CD73 deficient mice were subjected to TNCB induced CHS. In the different mouse strains the resulting ear swelling reaction was recorded along with a detailed phenotypic analysis of the skin migrating subsets of dendritic cells (DC). In CD73 deficient animals the motility of DC was higher as compared to wt animals and in particular after sensitization we found increased migration of Langerin + DC from skin to draining lymph nodes (LN). In the TNCB model this led to a stronger sensitization as indicated by increased frequency of interferon-γ producing T cells in the LN and an increased ear thickness after challenge. CD73 derived ADO production slows down migration of Langerin + DC from skin to LN. This may be a crucial mechanism to avoid over boarding immune reactions against haptens. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

  11. Actively Perceiving and Responsive Soft Robots Enabled by Self-Powered, Highly Extensible, and Highly Sensitive Triboelectric Proximity- and Pressure-Sensing Skins.

    Science.gov (United States)

    Lai, Ying-Chih; Deng, Jianan; Liu, Ruiyuan; Hsiao, Yung-Chi; Zhang, Steven L; Peng, Wenbo; Wu, Hsing-Mei; Wang, Xingfu; Wang, Zhong Lin

    2018-06-04

    Robots that can move, feel, and respond like organisms will bring revolutionary impact to today's technologies. Soft robots with organism-like adaptive bodies have shown great potential in vast robot-human and robot-environment applications. Developing skin-like sensory devices allows them to naturally sense and interact with environment. Also, it would be better if the capabilities to feel can be active, like real skin. However, challenges in the complicated structures, incompatible moduli, poor stretchability and sensitivity, large driving voltage, and power dissipation hinder applicability of conventional technologies. Here, various actively perceivable and responsive soft robots are enabled by self-powered active triboelectric robotic skins (tribo-skins) that simultaneously possess excellent stretchability and excellent sensitivity in the low-pressure regime. The tribo-skins can actively sense proximity, contact, and pressure to external stimuli via self-generating electricity. The driving energy comes from a natural triboelectrification effect involving the cooperation of contact electrification and electrostatic induction. The perfect integration of the tribo-skins and soft actuators enables soft robots to perform various actively sensing and interactive tasks including actively perceiving their muscle motions, working states, textile's dampness, and even subtle human physiological signals. Moreover, the self-generating signals can drive optoelectronic devices for visual communication and be processed for diverse sophisticated uses. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Sensitivity Comparison of the Skin Prick Test and Serum and Fecal Radio Allergosorbent Test (RAST in Diagnosis of Food Allergy in Children

    Directory of Open Access Journals (Sweden)

    Hamid Reza Kianifar

    2016-05-01

    Full Text Available Background: Diagnosis of food allergy is difficult in children. Food allergies are diagnosed using several methods that include medical histories, clinical examinations, skin prick and serum-specific immunoglobulin E (IgE tests, radio-allergosorbent test (RAST, food challenge, and supervised elimination diets. In this study we evaluated allergies to cow's milk, egg, peanut, and fish in children with suspected food allergies with skin prick tests and serum and feces RAST. Methods: Forty-one children with clinical symptoms of food allergies were enrolled in the study. Skin prick tests and serum and fecal RAST were performed and compared with challenge tests. Results: The most common sites of food allergy symptoms were gastrointestinal (82.9% and skin (48.8%. 100% of the patients responded to the challenge tests with cow’s milk, egg, peanut, and fish. 65% of the patients tested positive with the skin prick test, 12.1% tested positive with serum RAST, and 29.2% tested positive with fecal RAST. Conclusions: The skin prick test was more sensitive than serum or fecal RAST, and fecal RAST was more than twice as sensitive as serum RAST.

  13. PKCepsilon overexpression, irrespective of genetic background, sensitizes skin to UVR-induced development of squamous-cell carcinomas.

    Science.gov (United States)

    Sand, Jordan M; Aziz, Moammir H; Dreckschmidt, Nancy E; Havighurst, Thomas C; Kim, KyungMann; Oberley, Terry D; Verma, Ajit K

    2010-01-01

    Chronic exposure to UVR is the major etiologic factor in the development of human skin cancers including squamous-cell carcinoma (SCC). We have previously shown that protein Kinase C epsilon (PKCepsilon) transgenic mice on FVB/N background, which overexpress PKCepsilon protein approximately eightfold over endogenous levels in epidermis, exhibit about threefold more sensitivity than wild-type littermates to UVR-induced development of SCC. To determine whether it is PKCepsilon and not the mouse genetic background that determines susceptibility to UVR carcinogenesis, we cross-bred PKCepsilon FVB/N transgenic mice with SKH-1 hairless mice to generate PKCepsilon-overexpressing SKH-1 hairless mice. To evaluate the susceptibility of PKCepsilon SKH-1 hairless transgenic mice to UVR carcinogenesis, the mice were exposed to UVR (1-2 KJ m(-2)) three times weekly from a bank of six kodacel-filtered FS40 sunlamps. As compared with the wild-type hairless mice, PKCepsilon overexpression in SKH-1 hairless mice decreased the latency (12 weeks), whereas it increased the incidence (twofold) and multiplicity (fourfold) of SCC. The SKH hairless transgenic mice were observed to be as sensitive as FVB/N transgenic mice to UVR-induced development of SCC and expression of proliferative markers (proliferating cell nuclear antigen, signal transducers and activators of transcription 3, and extracellular signal-regulated kinase 1/2). The results indicate that PKCepsilon level dictates susceptibility, irrespective of genetic background, to UVR carcinogenesis.

  14. Coordinate sensitive detectors based on microchannel plates

    International Nuclear Information System (INIS)

    Gruntman, M.A.

    1984-01-01

    Coordinate-sensitive detectors (CSD) on the basis of microchannel plates permit to determine in a digital form the coordinates of every recorded particle and they are used in different fields of physical experiment. The sensitive surface diameter of such detectors can reach 10 cm, and spatial resolution - 10 μm. In the review provided CSD with microchannel plates are classified according to the ways of coordinate determination, different types of the detectors, pecUliarities of their design and electron flowsheet are described. It is pointed out that there are reasons for introduction of CSD into practice of laboratory physical investigations in various fields, where the particle recorded is electron or is able to form a secondary electron. It is attributed to nuclear physics, physics of electron and atom collisions, optics, mass-spectrometry, electron microscopy, X-ray analysis, investigation of surfaces

  15. β-adrenergic blockade does not impair the skin blood flow sensitivity to local heating in burned and non-burned skin under neutral and hot environments in children

    Science.gov (United States)

    Rivas, Eric; McEntire, Serina J.; Herndon, David N.; Mlcak, Ronald P.; Suman, Oscar E.

    2017-01-01

    Objective Tested the hypothesis that propranolol, a drug given to burn patients to reduce hypermetabolism/cardiac stress, may inhibit heat dissipation by changing the sensitivity of skin blood flow (SkBF) to local heating under neutral and hot conditions. Methods In a randomized double-blind study, a placebo was given to 8 burned children while propranolol was given to 13 burned children with similar characteristics (mean ± SD: 11.9±3y, 147±20cm, 45±23kg, 56±12% TBSA). Non-burned children (n=13, 11.4±3y, 152±15cm, 52±13kg) served as healthy controls. A progressive local heating protocol characterized SkBF responses in burned and unburned skin and non-burned control skin under the two environmental conditions (23°C and 34°C) via laser-Doppler flowmetry. Results Resting SkBF was greater in burned and unburned skin compared to the non-burned control (main effect: skin, Pburned; 38±36 unburned vs 9±8 control %SkBFmax). No difference was found for maximal SkBF capacity to local heating between groups. Additionally, dose response curves for the sensitivity of SkBF to local heating were not different among burned or unburned skin, and non-burned control skin (EC50, P>0.05) under either condition. Conclusion Therapeutic propranolol does not negatively affect SkBF under neutral or hot environmental conditions and further compromise temperature regulation in burned children. PMID:28071840

  16. mHealth App for Risk Assessment of Pigmented and Nonpigmented Skin Lesions-A Study on Sensitivity and Specificity in Detecting Malignancy.

    Science.gov (United States)

    Thissen, Monique; Udrea, Andreea; Hacking, Michelle; von Braunmuehl, Tanja; Ruzicka, Thomas

    2017-12-01

    With the advent of smartphone devices, an increasing number of mHealth applications that target melanoma identification have been developed, but none addresses the general context of melanoma and nonmelanoma skin cancer identification. In this study a smartphone application using fractal and classical image analysis for the risk assessment of skin lesions is systematically evaluated to determine its sensitivity and specificity in the diagnosis of melanoma and nonmelanoma skin cancer along with actinic keratosis and Bowen's disease. In the Department of Dermatology, Catharina Hospital Eindhoven, The Netherlands, 341 melanocytic and nonmelanocytic lesions were imaged using SkinVision app; 239 underwent histopathological examination, while the rest of 102 lesions were clinically diagnosed as clearly benign and not removed. The algorithm has been calibrated using the images of the first 233 lesions. The calibrated version of the algorithm was used in a subset of 108 lesions, and the obtained results were compared with the medical findings. On the 108 cases used for evaluation the algorithm scored 80% sensitivity and 78% specificity in detecting (pre)malignant conditions. Although less accurate than the dermatologist's clinical eye, the app may offer support to other professionals who are less familiar with differentiating between benign and malignant lesions. An mHealth application for the risk assessment of skin lesions was evaluated. It adds value to diagnosis tools of its type by taking into consideration pigmented and nonpigmented lesions all together and detecting signs of malignancy with high sensitivity.

  17. Subjective facial skin type, based on the sebum related symptoms, can reflect the objective casual sebum level in acne patients.

    Science.gov (United States)

    Choi, C W; Choi, J W; Youn, S W

    2013-05-01

    The relationship between the subjective skin type and the casual sebum level was not fully clarified. To investigate the characteristics of subjective skin type and to find the relationship between the subjective skin types and the skin type-related symptoms, casual sebum level, along with the objective skin type. Seven hundred and nine patients, clinically diagnosed with acne, were included. The questionnaire and the casual sebum level measurement were performed. The determining symptoms of each subjective skin type were investigated. The 95% confidence interval of casual sebum level of each subjective skin type was calculated. The most frequent subjective skin type was the combination type. The dryness, tightness, and oiliness can be conclusive symptoms in determining the subjective skin type. The mean and the 95% confidence interval of the casual sebum level was highest in the oily skin type, followed by the combination, normal, and dry skin type. We found that the subjective skin type was determined by the skin type-related symptoms. The 95% confidence intervals of the casual sebum level of each subjective skin type were established. Based on the skin type-related symptoms, the casual sebum level of acne patients can be estimated. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  18. Efficacy and dermal tolerance of a novel alcohol-based skin antiseptic in horses.

    Science.gov (United States)

    Tannahill, Victoria J; Cogan, Tristan; Allen, Kate; Acutt, Elizabeth; Busschers, Evita

    2018-04-14

    To determine the efficacy and dermal tolerance of a novel alcohol-based skin antiseptic (ABSA) in horses. Experimental study. Systemically healthy horses (n = 25) with no history or clinical signs of skin disease. Four clipped sites on the abdomen were randomly assigned to a skin preparation protocol: saline (negative control; NC), chlorhexidine gluconate followed by isopropyl alcohol (positive control; PC), saline followed by the ABSA (ABSA A), or a commercially available horse shampoo followed by the ABSA (ABSA B). Microbiological swabs were obtained from each site and cultured on MacConkey and mannitol salt agar plates. Colony-forming units were counted 18-24 hours later. All sites were scored for signs of skin reaction before, immediately after, 1 hour after, and 24 hours after skin preparation. The PC, ABSA A, and ABSA B methods reduced skin microbial burden compared with the NC method (P horses required veterinary treatment. The ABSA preparations tested in this study were as effective and well tolerated as a chlorhexidine gluconate-based method, but required less time in healthy horses. The ABSA tested here provides an efficacious, fast-acting, and well-tolerated alternative to achieve skin antisepsis in healthy horses. These results justify further investigation in clinical cases. © 2018 The American College of Veterinary Surgeons.

  19. Gene expression profiles in auricle skin as a possible additional endpoint for determination of sensitizers: A multi-endpoint evaluation of the local lymph node assay.

    Science.gov (United States)

    Tsuchiyama, Hiromi; Maeda, Akihisa; Nakajima, Mayumi; Kitsukawa, Mika; Takahashi, Kei; Miyoshi, Tomoya; Mutsuga, Mayu; Asaoka, Yoshiji; Miyamoto, Yohei; Oshida, Keiyu

    2017-10-05

    The murine local lymph node assay (LLNA) is widely used to test chemicals to induce skin sensitization. Exposure of mouse auricle skin to a sensitizer results in proliferation of local lymph node T cells, which has been measured by in vivo incorporation of H 3 -methyl thymidine or 5-bromo-2'-deoxyuridine (BrdU). The stimulation index (SI), the ratio of the mean proliferation in each treated group to that in the concurrent vehicle control group, is frequently used as a regulatory-authorized endpoint for LLNA. However, some non-sensitizing irritants, such as sodium dodecyl sulfate (SDS) or methyl salicylate (MS), have been reported as false-positives by this endpoint. In search of a potential endpoint to enhance the specificity of existing endpoints, we evaluated 3 contact sensitizers; (hexyl cinnamic aldehyde [HCA], oxazolone [OXA], and 2,4-dinitrochlorobenzene [DNCB]), 1 respiratory sensitizer (toluene 2,4-diisocyanate [TDI]), and 2 non-sensitizing irritants (MS and SDS) by several endpoints in LLNA. Each test substance was applied to both ears of female CBA/Ca mice daily for 3 consecutive days. The ears and auricle lymph node cells were analyzed on day 5 for endpoints including the SI value, lymph node cell count, cytokine release from lymph node cells, and histopathological changes and gene expression profiles in auricle skin. The SI values indicated that all the test substances induced significant proliferation of lymph node cells. The lymph node cell counts showed no significant changes by the non-sensitizers assessed. The inflammatory findings of histopathology were similar among the auricle skins treated by sensitizers and irritants. Gene expression profiles of cytokines IFN-γ, IL-4, and IL-17 in auricle skin were similar to the cytokine release profiles in draining lymph node cells. In addition, the gene expression of the chemokine CXCL1 and/or CXCL2 showed that it has the potential to discriminate sensitizers and non-sensitizing irritants. Our results

  20. SKIN SENSITIZATION AND ALLERGIC CONTACT DERMATITIS (BASIC COURSE): THE GLOBAL REGULATORY ENVIRONMENT - CONTINUING EDUCATION COURSE; 1 OF 4 SPEAKERS FOR AN SOT BASIC COURSE

    Science.gov (United States)

    New regulations have emerged in recent years giving guidance on how best to conduct skin sensitization testing on new chemical entities. For example, recently The Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) in the U.S. and the European Ce...

  1. Low sensitivity of type VII collagen enzyme-linked immunosorbent assay in epidermolysis bullosa acquisita : serration pattern analysis on skin biopsy is required for diagnosis

    NARCIS (Netherlands)

    Terra, J. B.; Jonkman, M. F.; Diercks, G. F. H.; Pas, H. H.

    BackgroundThe type VII collagen (coll VII) enzyme-linked immunosorbent assay (ELISA) has been reported to have high sensitivity (>93%) and specificity (>96%) for diagnosing epidermolysis bullosa acquisita (EBA) in patients who are seropositive on indirect immunofluorescence on salt-split skin (SSS).

  2. Comparison of Skin Moisturizer: Consumer-Based Brand Equity (CBBE Factors in Clusters Based on Consumer Ethnocentrism

    Directory of Open Access Journals (Sweden)

    Yossy Hanna Garlina

    2014-09-01

    Full Text Available This research aims to analyze relevant factors contributing to the four dimensions of consumer-based brand equity in skin moisturizer industry. It is then followed by the clustering of female consumers of skin moisturizer based on ethnocentrism and differentiating each cluster’s consumer-based brand equity dimensions towards a domestic skin moisturizer brand Mustika Ratu, skin moisturizer. Research used descriptive survey method analysis. Primary data was obtained through questionnaire distribution to 70 female respondents for factor analysis and 120 female respondents for cluster analysis and one way analysis of variance (ANOVA. This research employed factor analysis to obtain relevant factors contributing to the five dimensions of consumer-based brand equity in skin moisturizer industry. Cluster analysis and one way analysis of variance (ANOVA were to see the difference of consumer-based brand equity between highly ethnocentric consumer and low ethnocentric consumer towards the same skin moisturizer domestic brand, Mustika Ratu skin moisturizer. Research found in all individual dimension analysis, all variable means and individual means show distinct difference between the high ethnocentric consumer and the low ethnocentric consumer. The low ethnocentric consumer cluster tends to be lower in mean score of Brand Loyalty, Perceived Quality, Brand Awareness, Brand Association, and Overall Brand Equity than the high ethnocentric consumer cluster. Research concludes consumer ethnocentrism is positively correlated with preferences towards domestic products and negatively correlated with foreign-made product preference. It is, then, highly ethnocentric consumers have positive perception towards domestic product.

  3. Less skin irritation from alcohol-based disinfectant than from detergent used for hand disinfection

    DEFF Research Database (Denmark)

    Pedersen, L K; Held, E; Johansen, J D

    2005-01-01

    and forearms of 17 healthy volunteers. A control area was included. After 4 weeks an SLS patch was applied to each area. Irritant reactions were quantified with a visual score recording and measurements of transepidermal water loss (TEWL) and skin colour were performed on days 1, 5, 11, 38 and 40. RESULTS...... was found on the disinfectant-treated area compared with the control area and detergent area, and a similar trend was found for TEWL, although it was not statistically significant. CONCLUSION: Alcohol-based disinfectant caused less visible skin irritation and less skin barrier disruption than the use...

  4. Current application of phytocompound-based nanocosmeceuticals for beauty and skin therapy.

    Science.gov (United States)

    Ganesan, Palanivel; Choi, Dong-Kug

    2016-01-01

    Phytocompounds have been used in cosmeceuticals for decades and have shown potential for beauty applications, including sunscreen, moisturizing and antiaging, and skin-based therapy. The major concerns in the usage of phyto-based cosmeceuticals are lower penetration and high compound instability of various cosmetic products for sustained and enhanced compound delivery to the beauty-based skin therapy. To overcome these disadvantages, nanosized delivery technologies are currently in use for sustained and enhanced delivery of phyto-derived bioactive compounds in cosmeceutical sectors and products. Nanosizing of phytocompounds enhances the aseptic feel in various cosmeceutical products with sustained delivery and enhanced skin protecting activities. Solid lipid nanoparticles, transfersomes, ethosomes, nanostructured lipid carriers, fullerenes, and carbon nanotubes are some of the emerging nanotechnologies currently in use for their enhanced delivery of phytocompounds in skin care. Aloe vera, curcumin, resveratrol, quercetin, vitamins C and E, genistein, and green tea catechins were successfully nanosized using various delivery technologies and incorporated in various gels, lotions, and creams for skin, lip, and hair care for their sustained effects. However, certain delivery agents such as carbon nanotubes need to be studied for their roles in toxicity. This review broadly focuses on the usage of phytocompounds in various cosmeceutical products, nanodelivery technologies used in the delivery of phytocompounds to various cosmeceuticals, and various nanosized phytocompounds used in the development of novel nanocosmeceuticals to enhance skin-based therapy.

  5. A spectrofluorimetric sensor based on grape skin tissue for

    African Journals Online (AJOL)

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    Spectrofluorimetry has received considerable attention because of its rapid, simple, highly sensitive and selective advantages [1]. At present, some ... Unfortunately, Fe2+, Co2+, Sm3+ and Y3+ ions could cause interference [2]. A selective.

  6. Highly sensitive wearable strain sensor based on silver nanowires and nanoparticles

    Science.gov (United States)

    Shengbo, Sang; Lihua, Liu; Aoqun, Jian; Qianqian, Duan; Jianlong, Ji; Qiang, Zhang; Wendong, Zhang

    2018-06-01

    Here, we propose a highly sensitive and stretchable strain sensor based on silver nanoparticles and nanowires (Ag NPs and NWs), advancing the rapid development of electronic skin. To improve the sensitivity of strain sensors based on silver nanowires (Ag NWs), Ag NPs and NWs were added to polydimethylsiloxane (PDMS) as an aid filler. Silver nanoparticles (Ag NPs) increase the conductive paths for electrons, leading to the low resistance of the resulting sensor (14.9 Ω). The strain sensor based on Ag NPs and NWs showed strong piezoresistivity with a tunable gauge factor (GF) at 3766, and a change in resistance as the strain linearly increased from 0% to 28.1%. The high GF demonstrates the irreplaceable role of Ag NPs in the sensor. Moreover, the applicability of our high-performance strain sensor has been demonstrated by its ability to sense movements caused by human talking, finger bending, wrist raising and walking.

  7. Variance-based sensitivity indices for models with dependent inputs

    International Nuclear Information System (INIS)

    Mara, Thierry A.; Tarantola, Stefano

    2012-01-01

    Computational models are intensively used in engineering for risk analysis or prediction of future outcomes. Uncertainty and sensitivity analyses are of great help in these purposes. Although several methods exist to perform variance-based sensitivity analysis of model output with independent inputs only a few are proposed in the literature in the case of dependent inputs. This is explained by the fact that the theoretical framework for the independent case is set and a univocal set of variance-based sensitivity indices is defined. In the present work, we propose a set of variance-based sensitivity indices to perform sensitivity analysis of models with dependent inputs. These measures allow us to distinguish between the mutual dependent contribution and the independent contribution of an input to the model response variance. Their definition relies on a specific orthogonalisation of the inputs and ANOVA-representations of the model output. In the applications, we show the interest of the new sensitivity indices for model simplification setting. - Highlights: ► Uncertainty and sensitivity analyses are of great help in engineering. ► Several methods exist to perform variance-based sensitivity analysis of model output with independent inputs. ► We define a set of variance-based sensitivity indices for models with dependent inputs. ► Inputs mutual contributions are distinguished from their independent contributions. ► Analytical and computational tests are performed and discussed.

  8. Smartphone-based fluorescence spectroscopy device aiding in preliminary skin screening

    Science.gov (United States)

    Sahoo, Aparajita; Wahi, Akshat; Das, Anshuman

    2018-02-01

    Preliminary diagnosis of closely resembling skin conditions can be highly subjective for dermatologists. In ambiguous cases, it often leads to performing invasive procedures like biopsies. Different skin conditions, however, have varying concentrations of fluorophores (like collagen, NADH) and chromophores (like melanin, hemoglobin) which can alter their fluorescence spectra. We demonstrate a handheld, portable, smartphone-based spectrometer that leverages these alterations in skin autofluorescence spectra for rapid screening of skin conditions. This methodology involves excitation of affected skin areas with ultraviolet (UV-A) 385 nm light, capturing the generated fluorescence spectra and sending the data wirelessly to a companion mobile application for data storage, analysis and visualization. By collecting the fluorescence spectral signals from healthy and unhealthy skin conditions, we establish that the signals collected using this portable device can be used to develop a classification method to help in differentially diagnosing these conditions. It shows promise as a useful skin screening tool for both dermatologists and primary health care workers. This device can enable quick, non-invasive and a more objective preliminary examination. We envision the device to be especially useful in primary healthcare centers of developing countries where availability of dermatologists is limited.

  9. X ray sensitivity of diploid skin fibroblasts from patients with Fanconi's anemia

    Science.gov (United States)

    Kale, Ranjini

    1989-01-01

    Experiments were performed on Fanconi's anemia and normal human fibroblast cell lines growing in culture in an attempt to correlate cell cycle kinetics with genomic damage and determine their bearing on the mechanism of chromosome aberration induction. FA fibroblasts showed a significantly increased susceptibility to chromosomal breakage by x rays in the G2 phase of the cell cycle. No such response was observed in fibroblasts irradiated in the G0 phase. The observed increases in achromatic lesions and in chromatid deletions in FA cells as compared with normal cells appear to indicate that FA cells are deficient in strand break repair and also possibly in base damage excision repair. Experiments are now in progress to further elucidate the mechanisms involved.

  10. Developing context sensitive BIM based applications

    NARCIS (Netherlands)

    Hartmann, Timo; Underwood, J.; Isikdag, U.

    2010-01-01

    Current Building Information Model (BIM) based applications do not integrate well with the varying and frequently changing work processes of Architectural, Engineering, and Construction (AEC) professionals. One cause for this problem is that traditionally software developers apply software design

  11. Chemical stability and in chemico reactivity of 24 fragrance ingredients of concern for skin sensitization risk assessment.

    Science.gov (United States)

    Avonto, Cristina; Wang, Mei; Chittiboyina, Amar G; Vukmanovic, Stanislav; Khan, Ikhlas A

    2018-02-01

    Twenty-four pure fragrance ingredients have been identified as potential concern for skin sensitization. Several of these compounds are chemically unstable and convert into reactive species upon exposure to air or light. In the present work, a systematic investigation of the correlation between chemical stability and reactivity has been undertaken. The compounds were subjected to forced photodegradation for three months and the chemical changes were studied with GC-MS. At the end of the stability study, two-thirds of the samples were found to be unstable. The generation of chemically reactive species was investigated using the in chemico HTS-DCYA assay. Eleven and fourteen compounds were chemically reactive before and after three months, respectively. A significant increase in reactivity upon degradation was found for isoeugenol, linalool, limonene, lyral, citronellol and geraniol; in the same conditions, the reactivity of hydroxycitronellal decreased. The non-reactive compounds α-isomethyl ionone, benzyl alcohol, amyl cinnamal and farnesol became reactive after photo-oxidative degradation. Overall, forced degradation resulted in four non-reactive fragrance compounds to display in chemico thiol reactivity, while ten out of 24 compounds remained inactive. Chemical degradation does not necessarily occur with generation of reactive species. Non-chemical activation may be involved for the 10 stable unreactive compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. A sensitization effect of hematoporphyrin oligomer (HpO) and caffeine for X-ray radiation of skin cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ishiguro, Kazumori; Ueda, Keiichi; Miyoshi, Norio; Nakanishi, Kazuo; Fukuda, Masaru (Fukui Medical School, Matsuoka (Japan))

    1990-05-01

    Human malignant melanoma cells (G-361) were irradiated with X-ray for different irradiation times. The amount of DNA damage was much increased by the treatment of the cells with hematoporphyrin oligomer (HpO) before X-ray irradiation. Furthermore, it was found that the caffeine inhibited effectively the repair of the damaged DNA. Furthermore, HpO was administered before X-ray irradiation of transplantable skin tumor in C3H mice and/or caffeine was to be given the mouse after X-ray irradiation. The growth of the irradiated tumor combined with HpO and/or caffeine was more inhibited, and the necrotic area was more expanded than that of the tumor irradiated with X-ray only. Labeling Index utilizing bromodeoxyuridine (BrdU) in the viable area of the treated tumor decreased when HpO and/or caffeine were administered. The amount of DNA damage more increased in the irradiated tumor cells given HpO than the only irradiated cells. And, the repair of the damaged DNA was more delayed in the irradiated tumor cells combined with HpO and caffeine than those with other treatments. In conclusion, it was considered that HpO might be a radioactive sensitizer and caffeine enhanced the inhibition of the repair of DNA damaged. We hope that the treatment of X-ray radiation combined with HpO and caffeine is useful for clinical treatment of human malignant tumor. (author) 54 refs.

  13. A sensitization effect of hematoporphyrin oligomer (HpO) and caffeine for X-ray radiation of skin cancer

    International Nuclear Information System (INIS)

    Ishiguro, Kazumori; Ueda, Keiichi; Miyoshi, Norio; Nakanishi, Kazuo; Fukuda, Masaru

    1990-01-01

    Human malignant melanoma cells (G-361) were irradiated with X-ray for different irradiation times. The amount of DNA damage was much increased by the treatment of the cells with hematoporphyrin oligomer (HpO) before X-ray irradiation. Furthermore, it was found that the caffeine inhibited effectively the repair of the damaged DNA. Furthermore, HpO was administered before X-ray irradiation of transplantable skin tumor in C3H mice and/or caffeine was to be given the mouse after X-ray irradiation. The growth of the irradiated tumor combined with HpO and/or caffeine was more inhibited, and the necrotic area was more expanded than that of the tumor irradiated with X-ray only. Labeling Index utilizing bromodeoxyuridine (BrdU) in the viable area of the treated tumor decreased when HpO and/or caffeine were administered. The amount of DNA damage more increased in the irradiated tumor cells given HpO than the only irradiated cells. And, the repair of the damaged DNA was more delayed in the irradiated tumor cells combined with HpO and caffeine than those with other treatments. In conclusion, it was considered that HpO might be a radioactive sensitizer and caffeine enhanced the inhibition of the repair of DNA damaged. We hope that the treatment of X-ray radiation combined with HpO and caffeine is useful for clinical treatment of human malignant tumor. (author) 54 refs

  14. Skin sensitization potency of isoeugenol and its dimers evaluated by a non-radioisotopic modification of the local lymph node assay and guinea pig maximization test.

    Science.gov (United States)

    Takeyoshi, Masahiro; Iida, Kenji; Suzuki, Keiko; Yamazaki, Shunsuke

    2008-05-01

    Allergic contact dermatitis is the serious unwanted effect arising from the use of consumer products such as cosmetics. Isoeugenol is a fragrance chemical with spicy, carnation-like scent, is used in many kinds of cosmetics and is a well-known moderate human sensitizer. It was previously reported that the dimerization of eugenol yielded two types of dimer possessing different sensitization potencies. This study reports the differences in skin sensitization potencies for isoeugenol and two types of dimer, beta-O-4-dilignol and dehydrodiisoeugenol (DIEG), as evaluated by the non-radioisotopic local lymph node assay (non-RI LLNA) and guinea pig maximization test. In the guinea pig maximization test, isoeugenol, beta-O-4-dilignol and DIEG were classified as extreme, weak and moderate sensitizers, respectively. As for the results of non-RI LLNA, the EC3 for isoeugenol, beta-O-4-dilignol and DIEG were calculated as 12.7%, >30% and 9.4%, respectively. The two types of isoeugenol dimer showed different sensitizing activities similar to the case for eugenol dimers. A reduction of sensitization potency achieved by dimerization may lead to developing safer cosmetic ingredients. Isoeugenol dimers are not currently used for fragrance chemicals. However, the dimerization of isoeugenol may yield a promising candidate as a cosmetic ingredient with low sensitization risk. The data may also provide useful information for the structure-activity relationship (SAR) in skin sensitization. Copyright (c) 2007 John Wiley & Sons, Ltd.

  15. Cyanex based uranyl sensitive polymeric membrane electrodes.

    Science.gov (United States)

    Badr, Ibrahim H A; Zidan, W I; Akl, Z F

    2014-01-01

    Novel uranyl selective polymeric membrane electrodes were prepared using three different low-cost and commercially available Cyanex extractants namely, bis(2,4,4-trimethylpentyl) phosphinic acid [L1], bis(2,4,4-trimethylpentyl) monothiophosphinic acid [L2] and bis(2,4,4-trimethylpentyl) dithiophosphinic acid [L3]. Optimization and performance characteristics of the developed Cyanex based polymer membrane electrodes were determined. The influence of membrane composition (e.g., amount and type of ionic sites, as well as type of plasticizer) on potentiometric responses of the prepared membrane electrodes was studied. Optimized Cyanex-based membrane electrodes exhibited Nernstian responses for UO₂(2+) ion over wide concentration ranges with fast response times. The optimized membrane electrodes based on L1, L2 and L3 exhibited Nernstian responses towards uranyl ion with slopes of 29.4, 28.0 and 29.3 mV decade(-1), respectively. The optimized membrane electrodes based on L1-L3 showed detection limits of 8.3 × 10(-5), 3.0 × 10(-5) and 3.3 × 10(-6) mol L(-1), respectively. The selectivity studies showed that the optimized membrane electrodes exhibited high selectivity towards UO₂(2+) ion over large number of other cations. Membrane electrodes based on L3 exhibited superior potentiometric response characteristics compared to those based on L1 and L2 (e.g., widest linear range and lowest detection limit). The analytical utility of uranyl membrane electrodes formulated with Cyanex extractant L3 was demonstrated by the analysis of uranyl ion in different real samples for nuclear safeguards verification purposes. The results obtained using direct potentiometry and flow-injection methods were compared with those measured using the standard UV-visible and inductively coupled plasma spectroscopic methods. © 2013 Published by Elsevier B.V.

  16. Low Power and High Sensitivity MOSFET-Based Pressure Sensor

    International Nuclear Information System (INIS)

    Zhang Zhao-Hua; Ren Tian-Ling; Zhang Yan-Hong; Han Rui-Rui; Liu Li-Tian

    2012-01-01

    Based on the metal-oxide-semiconductor field effect transistor (MOSFET) stress sensitive phenomenon, a low power MOSFET pressure sensor is proposed. Compared with the traditional piezoresistive pressure sensor, the present pressure sensor displays high performances on sensitivity and power consumption. The sensitivity of the MOSFET sensor is raised by 87%, meanwhile the power consumption is decreased by 20%. (cross-disciplinary physics and related areas of science and technology)

  17. Sensitivity Enhancement of FBG-Based Strain Sensor.

    Science.gov (United States)

    Li, Ruiya; Chen, Yiyang; Tan, Yuegang; Zhou, Zude; Li, Tianliang; Mao, Jian

    2018-05-17

    A novel fiber Bragg grating (FBG)-based strain sensor with a high-sensitivity is presented in this paper. The proposed FBG-based strain sensor enhances sensitivity by pasting the FBG on a substrate with a lever structure. This typical mechanical configuration mechanically amplifies the strain of the FBG to enhance overall sensitivity. As this mechanical configuration has a high stiffness, the proposed sensor can achieve a high resonant frequency and a wide dynamic working range. The sensing principle is presented, and the corresponding theoretical model is derived and validated. Experimental results demonstrate that the developed FBG-based strain sensor achieves an enhanced strain sensitivity of 6.2 pm/με, which is consistent with the theoretical analysis result. The strain sensitivity of the developed sensor is 5.2 times of the strain sensitivity of a bare fiber Bragg grating strain sensor. The dynamic characteristics of this sensor are investigated through the finite element method (FEM) and experimental tests. The developed sensor exhibits an excellent strain-sensitivity-enhancing property in a wide frequency range. The proposed high-sensitivity FBG-based strain sensor can be used for small-amplitude micro-strain measurement in harsh industrial environments.

  18. Face Liveness Detection Based on Skin Blood Flow Analysis

    Directory of Open Access Journals (Sweden)

    Shun-Yi Wang

    2017-12-01

    Full Text Available Face recognition systems have been widely adopted for user authentication in security systems due to their simplicity and effectiveness. However, spoofing attacks, including printed photos, displayed photos, and replayed video attacks, are critical challenges to authentication, and these spoofing attacks allow malicious invaders to gain access to the system. This paper proposes two novel features for face liveness detection systems to protect against printed photo attacks and replayed attacks for biometric authentication systems. The first feature obtains the texture difference between red and green channels of face images inspired by the observation that skin blood flow in the face has properties that enable distinction between live and spoofing face images. The second feature estimates the color distribution in the local regions of face images, instead of whole images, because image quality might be more discriminative in small areas of face images. These two features are concatenated together, along with a multi-scale local binary pattern feature, and a support vector machine classifier is trained to discriminate between live and spoofing face images. The experimental results show that the performance of the proposed method for face spoof detection is promising when compared with that of previously published methods. Furthermore, the proposed system can be implemented in real time, which is valuable for mobile applications.

  19. Large-proportional shrunken bio-replication of shark skin based on UV-curing shrinkage

    International Nuclear Information System (INIS)

    Chen, Huawei; Che, Da; Zhang, Xin; Yue, Yue; Zhang, Deyuan

    2015-01-01

    The shark skin effect has attracted worldwide attention because of its superior drag reduction. As the product of natural selection, the maximum drag reduction of shark skin is found in its normal living environment. Large-proportional shrinkage of shark skin morphology is greatly anticipated for its adaptation to faster fluid flow. One novel approach, large-proportional shrunken bio-replication, is proposed as a method to adjust the optimal drag reduction region of shark skin based on the shrinkage of UV-cured material. The shark skin is taken as a replica template to allow large-proportional shrinking in the drag reduction morphology by taking advantage of the shrinkage of UV-curable material. The accuracy of the large-proportional shrunken bio-replication approach is verified by a comparison between original and shrunken bio-replicated shark skin, which shows that the shrinking ratio can reach 23% and the bio-replication accuracy is higher than 95%. In addition, the translation of the optimum drag reduction peak of natural surface function to various applications and environments is proved by drag reduction experiments. (technical note)

  20. Resurfacing glabrous skin defects in the hand: the thenar base donor site.

    Science.gov (United States)

    Milner, Chris S; Thirkannad, Sunil M

    2014-06-01

    Defects of the glabrous skin surfaces of the palm and fingers result from numerous causes including larger fingertip injuries, unhealed burns, and after surgery for diverse pathologies. The qualities of glabrous skin are specifically tailored to the functional requirements of high-shear strength and robustness. Despite these unique properties, graft reconstruction of defects in the glabrous regions of the hand is frequently achieved with skin from nonglabrous donor sites such as the medial forearm. Nonglabrous skin has a poor color and texture match for such applications and is frequently associated with tender and unsightly donor scars. We describe our experiences of harvesting full-thickness grafts from the glabrous skin centered over the proximal flexion crease at the level of the metacarpophalangeal joint of the thumb. We have utilized this site to harvest skin grafts of up to 2 cm in width for the resurfacing of small-sized to medium-sized defects on the palmar surfaces of the hands and fingers in 28 patients under both traumatic and elective circumstances. The skin has an excellent type-match to the defect and is quick and easy to harvest due to its adjacent location to the defect. The donor scar matures quickly, and as it lies along the thumb base crease, it runs along one of the least used contact surfaces, thereby limiting the potential discomfort associated with FTSG harvest sites from other areas. Patient satisfaction with the procedure has been high, and it represents a useful alternative to traditional nonglabrous skin graft donor sites for small-sized to medium-sized defects.

  1. Hydrogel-based ultra-moisturizing cream formulation for skin hydration and enhanced dermal drug delivery.

    Science.gov (United States)

    Lee, Sang Gon; Kim, Sung Rae; Cho, Hye In; Kang, Mean Hyung; Yeom, Dong Woo; Lee, Seo Hyun; Lee, Sangkil; Choi, Young Wook

    2014-01-01

    To develop an external vehicle for skin hydration and enhanced dermal drug delivery, a hydrogel-based ultra-moisturizing cream (HUMC) was successfully formulated with carbopol 934P, urea, Tinocare GL, grape seed oil, and other excipients. The HUMC showed plastic flow behavior due to a gel structure with a cream base. Different types of drug-free vehicles such as a hydrogel, conventional cream (CC), and three HUMCs were prepared and subjected to an in vivo skin hydration test on a hairless mouse using a corneometer. Hydration effect (∆AU) was in the order of HUMC2>HUMC1 ≥ CC>HUMC3>hydrogel. Using nile red (NR) and 5-carboxyfluorescein (5-CF) as lipophilic and hydrophilic fluorescent probes, respectively, in vitro skin permeation and accumulation studies were conducted using Franz diffusion cells. The values of steady-state flux (Jss, ng/h/cm(2)) were obtained: 74.8 (CC), 145.6 (HUMC1), and 161.9 (HUMC2) for NR delivery; 6.8 (CC), 8.3 (HUMC1), and 10.9 (HUMC2) for 5-CF delivery. The amounts retained in the skin at 12 h (Qr, ng/cm(2)) were determined: 86.4 (CC) and 102.0 (HUMC2) for NR; and 70.1 (CC) and 195.6 (HUMC2) for 5-CF. Confocal microscopy was used to visualize the distribution of the fluorescent probes. NR tended to be localized into the deeper part of the skin with adipose tissue whereas 5-CF localized in the upper layer of the skin. Thus we propose that HUMC2 is an efficacious vehicle for skin hydration and enhances dermal delivery of lipophilic and hydrophilic drugs.

  2. On-Skin Interaction Using Body Landmarks

    DEFF Research Database (Denmark)

    Steimle, Juergen; Bergstrom-Lehtovirta, Joanna; Weigel, Martin

    2017-01-01

    The human skin is a promising surface for input to computing devices but differs fundamentally from existing touch-sensitive devices. The authors propose the use of skin landmarks, which offer unique tactile and visual cues, to enhance body-based user interfaces....

  3. Flexible, highly sensitive pressure sensor with a wide range based on graphene-silk network structure

    Science.gov (United States)

    Liu, Ying; Tao, Lu-Qi; Wang, Dan-Yang; Zhang, Tian-Yu; Yang, Yi; Ren, Tian-Ling

    2017-03-01

    In this paper, a flexible, simple-preparation, and low-cost graphene-silk pressure sensor based on soft silk substrate through thermal reduction was demonstrated. Taking silk as the support body, the device had formed a three-dimensional structure with ordered multi-layer structure. Through a simple and low-cost process technology, graphene-silk pressure sensor can achieve the sensitivity value of 0.4 kPa - 1 , and the measurement range can be as high as 140 kPa. Besides, pressure sensor can have a good combination with knitted clothing and textile product. The signal had good reproducibility in response to different pressures. Furthermore, graphene-silk pressure sensor can not only detect pressure higher than 100 kPa, but also can measure weak body signals. The characteristics of high-sensitivity, good repeatability, flexibility, and comfort for skin provide the high possibility to fit on various wearable electronics.

  4. Feasibility Study on a Microwave-Based Sensor for Measuring Hydration Level Using Human Skin Models.

    Science.gov (United States)

    Brendtke, Rico; Wiehl, Michael; Groeber, Florian; Schwarz, Thomas; Walles, Heike; Hansmann, Jan

    2016-01-01

    Tissue dehydration results in three major types of exsiccosis--hyper-, hypo-, or isonatraemia. All three types entail alterations of salt concentrations leading to impaired biochemical processes, and can finally cause severe morbidity. The aim of our study was to demonstrate the feasibility of a microwave-based sensor technology for the non-invasive measurement of the hydration status. Electromagnetic waves at high frequencies interact with molecules, especially water. Hence, if a sample contains free water molecules, this can be detected in a reflected microwave signal. To develop the sensor system, human three-dimensional skin equivalents were instituted as a standardized test platform mimicking reproducible exsiccosis scenarios. Therefore, skin equivalents with a specific hydration and density of matrix components were generated and microwave measurements were performed. Hydration-specific spectra allowed deriving the hydration state of the skin models. A further advantage of the skin equivalents was the characterization of the impact of distinct skin components on the measured signals to investigate mechanisms of signal generation. The results demonstrate the feasibility of a non-invasive microwave-based hydration sensor technology. The sensor bears potential to be integrated in a wearable medical device for personal health monitoring.

  5. Feasibility Study on a Microwave-Based Sensor for Measuring Hydration Level Using Human Skin Models.

    Directory of Open Access Journals (Sweden)

    Rico Brendtke

    Full Text Available Tissue dehydration results in three major types of exsiccosis--hyper-, hypo-, or isonatraemia. All three types entail alterations of salt concentrations leading to impaired biochemical processes, and can finally cause severe morbidity. The aim of our study was to demonstrate the feasibility of a microwave-based sensor technology for the non-invasive measurement of the hydration status. Electromagnetic waves at high frequencies interact with molecules, especially water. Hence, if a sample contains free water molecules, this can be detected in a reflected microwave signal. To develop the sensor system, human three-dimensional skin equivalents were instituted as a standardized test platform mimicking reproducible exsiccosis scenarios. Therefore, skin equivalents with a specific hydration and density of matrix components were generated and microwave measurements were performed. Hydration-specific spectra allowed deriving the hydration state of the skin models. A further advantage of the skin equivalents was the characterization of the impact of distinct skin components on the measured signals to investigate mechanisms of signal generation. The results demonstrate the feasibility of a non-invasive microwave-based hydration sensor technology. The sensor bears potential to be integrated in a wearable medical device for personal health monitoring.

  6. Current application of phytocompound-based nanocosmeceuticals for beauty and skin therapy

    Directory of Open Access Journals (Sweden)

    Ganesan P

    2016-05-01

    Full Text Available Palanivel Ganesan,1,2 Dong-Kug Choi1,2 1Department of Applied Life Science, Nanotechnology Research Center, 2Department of Biotechnology, College of Biomedical and Health Science, Konkuk University, Chungju, Republic of Korea Abstract: Phytocompounds have been used in cosmeceuticals for decades and have shown potential for beauty applications, including sunscreen, moisturizing and antiaging, and skin-based therapy. The major concerns in the usage of phyto-based cosmeceuticals are lower penetration and high compound instability of various cosmetic products for sustained and enhanced compound delivery to the beauty-based skin therapy. To overcome these disadvantages, nanosized delivery technologies are currently in use for sustained and enhanced delivery of phyto-derived bioactive compounds in cosmeceutical sectors and products. Nanosizing of phytocompounds enhances the aseptic feel in various cosmeceutical products with sustained delivery and enhanced skin protecting activities. Solid lipid nanoparticles, transfersomes, ethosomes, nanostructured lipid carriers, fullerenes, and carbon nanotubes are some of the emerging nanotechnologies currently in use for their enhanced delivery of phytocompounds in skin care. Aloe vera, curcumin, resveratrol, quercetin, vitamins C and E, genistein, and green tea catechins were successfully nanosized using various delivery technologies and incorporated in various gels, lotions, and creams for skin, lip, and hair care for their sustained effects. However, certain delivery agents such as carbon nanotubes need to be studied for their roles in toxicity. This review broadly focuses on the usage of phytocompounds in various cosmeceutical products, nanodelivery technologies used in the delivery of phytocompounds to various cosmeceuticals, and various nanosized phytocompounds used in the development of novel nanocosmeceuticals to enhance skin-based therapy. Keywords: nanodelivery technologies, skincare

  7. Assessment of skin sensitization under REACH: A case report on vehicle choice in the LLNA and its crucial role preventing false positive results.

    Science.gov (United States)

    Watzek, Nico; Berger, Franz; Kolle, Susanne Noreen; Kaufmann, Tanja; Becker, Matthias; van Ravenzwaay, Bennard

    2017-04-01

    In the EU, chemicals with a production or import volume in quantities of one metric ton per year or more have to be tested for skin sensitizing properties under the REACH regulation. The murine Local Lymph Node Assay (LLNA) and its modifications are widely used to fulfil the data requirement, as it is currently considered the first-choice method for in vivo testing to cover this endpoint. This manuscript describes a case study highlighting the importance of understanding the chemistry of the test material during testing for 'skin sensitization' of MCDA (mixture of 2,4- and 2,6-diamino-methylcyclohexane) with particular focus on the vehicle used. While the BrdU-ELISA modification of the LLNA using acetone/olive oil (AOO) as vehicle revealed expectable positive results. However, the concentration control analysis unexpectedly revealed an instability of MCDA in the vehicle AOO. Further studies on the reactivity showed MCDA to rapidly react with AOO under formation of various imine structures, which might have caused the positive LLNA result. The repetition of the LLNA using propylene glycol (PG) as vehicle did not confirm the positive results of the LLNA using AOO. Finally, a classification of MCDA as skin sensitizer according to the Globally Harmonized System (GHS) was not justified. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Risk of sensitization in healthy adults following repeated administration of rdESAT-6 skin test reagent by the Mantoux injection technique

    DEFF Research Database (Denmark)

    Lillebaek, Troels; Bergstedt, Winnie; Tingskov, Pernille N

    2009-01-01

    1 open clinical trial was to assess the sensitization risk and safety of repeated administration of rdESAT-6 reagent in 31 healthy adult volunteers. Three groups of volunteers received two fixed doses of 0.1 microg rdESAT-6 28, 56 or 112 days apart, respectively. After the second injection...... of 31 (3%) volunteers showed a positive skin reaction (sensitization) upon a second injection of rdESAT-6 after 28days and an increased IFN-gamma response to ESAT-6. For 7 (23%) of the volunteers, local adverse reactions related to the product were registered, but all reactions were mild and predictable...

  9. A Quantitative Risk Assessment of the Skin Sensitization Induction Potential of the Kathon CG Preservative in Rinse-off and Leave-on Personal Care and Cosmetic Products.

    Science.gov (United States)

    Towle, Kevin M; Drechsel, Derek A; Warshaw, Erin M; Fung, Ernest S; Novick, Rachel M; Paustenbach, Dennis J; Monnot, Andrew D

    2018-03-22

    Kathon CG is a commonly used cosmetic-grade preservative that contains active ingredients methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI). The aim of the study was to perform a skin sensitization induction risk assessment of daily exposure to Kathon CG after use of various personal care and cosmetic products. We calculated an estimated daily consumer exposure level for rinse-off and leave-on products using the amount of product applied per application, number of applications per day, a retention factor, the MCI/MI concentration, and body surface area values. We assumed that the products contained the maximum recommended safe concentration of MCI/MI: 15 ppm in rinse-off products and 7.5 ppm in leave-on products. We compared estimated consumer exposure levels with the no expected sensitization induction level for MCI/MI and applied sensitization assessment factors to calculate product-specific margins of safety (MOSs). The MOSs for rinse-off products ranged from 5 to 63, whereas the MOSs for leave-on products ranged from 0.03 to 1.49. Overall, our results provide evidence that some leave-on products containing the maximum recommended safe concentration of Kathon CG may increase the risk of sensitization induction due to exposure to MCI/MI. In contrast, rinse-off products were not associated with a potential increased risk of skin sensitization induction.

  10. N -annulated perylene-based push-pull-type sensitizers

    KAUST Repository

    Qi, Qingbiao; Wang, Xingzhu; Fan, Li; Zheng, Bin; Zeng, Wangdong; Luo, Jie; Huang, Kuo-Wei; Wang, Qing; Wu, Jishan

    2015-01-01

    Alkoxy-wrapped N-annulated perylene (NP) was synthesized and used as a rigid and coplanar π-linker for three push-pull type metal-free sensitizers QB1-QB3. Their optical and electrochemical properties were tuned by varying the structure of acceptor. These new dyes were applied in Co(II)/(III) based dye-sensitized solar cells, and power conversion efficiency up to 6.95% was achieved, indicating that NP could be used as a new building block for the design of high-performance sensitizers in the future.

  11. N -annulated perylene-based push-pull-type sensitizers

    KAUST Repository

    Qi, Qingbiao

    2015-02-06

    Alkoxy-wrapped N-annulated perylene (NP) was synthesized and used as a rigid and coplanar π-linker for three push-pull type metal-free sensitizers QB1-QB3. Their optical and electrochemical properties were tuned by varying the structure of acceptor. These new dyes were applied in Co(II)/(III) based dye-sensitized solar cells, and power conversion efficiency up to 6.95% was achieved, indicating that NP could be used as a new building block for the design of high-performance sensitizers in the future.

  12. Variable screening and ranking using sampling-based sensitivity measures

    International Nuclear Information System (INIS)

    Wu, Y-T.; Mohanty, Sitakanta

    2006-01-01

    This paper presents a methodology for screening insignificant random variables and ranking significant important random variables using sensitivity measures including two cumulative distribution function (CDF)-based and two mean-response based measures. The methodology features (1) using random samples to compute sensitivities and (2) using acceptance limits, derived from the test-of-hypothesis, to classify significant and insignificant random variables. Because no approximation is needed in either the form of the performance functions or the type of continuous distribution functions representing input variables, the sampling-based approach can handle highly nonlinear functions with non-normal variables. The main characteristics and effectiveness of the sampling-based sensitivity measures are investigated using both simple and complex examples. Because the number of samples needed does not depend on the number of variables, the methodology appears to be particularly suitable for problems with large, complex models that have large numbers of random variables but relatively few numbers of significant random variables

  13. Multilayer detector for skin absorbed dose measuring

    International Nuclear Information System (INIS)

    Osanov, D.P.; Panova, V.P.; Shaks, A.I.

    1985-01-01

    A method for skin dosimetry based on utilization of multilayer detectors and permitting to estimate distribution of absorbed dose by skin depth is described. The detector represents a set of thin sensitive elements separated by tissue-equivalent absorbers. Quantitative evaluation and forecasting the degree of radiation injury of skin are determined by the formula based on determination of the probability of the fact that cells are not destroyed and they can divide further on. The given method ensures a possibility of quantitative evaluation of radiobiological effect and forecasting clinical consequences of skin irradiation by results of corresponding measurements of dose by means of the miultilayer detector

  14. Universal in vivo Textural Model for Human Skin based on Optical Coherence Tomograms.

    Science.gov (United States)

    Adabi, Saba; Hosseinzadeh, Matin; Noei, Shahryar; Conforto, Silvia; Daveluy, Steven; Clayton, Anne; Mehregan, Darius; Nasiriavanaki, Mohammadreza

    2017-12-20

    Currently, diagnosis of skin diseases is based primarily on the visual pattern recognition skills and expertise of the physician observing the lesion. Even though dermatologists are trained to recognize patterns of morphology, it is still a subjective visual assessment. Tools for automated pattern recognition can provide objective information to support clinical decision-making. Noninvasive skin imaging techniques provide complementary information to the clinician. In recent years, optical coherence tomography (OCT) has become a powerful skin imaging technique. According to specific functional needs, skin architecture varies across different parts of the body, as do the textural characteristics in OCT images. There is, therefore, a critical need to systematically analyze OCT images from different body sites, to identify their significant qualitative and quantitative differences. Sixty-three optical and textural features extracted from OCT images of healthy and diseased skin are analyzed and, in conjunction with decision-theoretic approaches, used to create computational models of the diseases. We demonstrate that these models provide objective information to the clinician to assist in the diagnosis of abnormalities of cutaneous microstructure, and hence, aid in the determination of treatment. Specifically, we demonstrate the performance of this methodology on differentiating basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) from healthy tissue.

  15. Skin Autofluorescence Based Decision Tree in Detection of Impaired Glucose Tolerance and Diabetes

    NARCIS (Netherlands)

    Smit, Andries J.; Smit, Jitske M.; Botterblom, Gijs J.; Mulder, Douwe

    2013-01-01

    Aim: Diabetes (DM) and impaired glucose tolerance (IGT) detection are conventionally based on glycemic criteria. Skin autofluorescence (SAF) is a noninvasive proxy of tissue accumulation of advanced glycation endproducts (AGE) which are considered to be a carrier of glycometabolic memory. We

  16. A library based fitting method for visual reflectance spectroscopy of human skin

    Energy Technology Data Exchange (ETDEWEB)

    Verkruysse, Wim [Beckman Laser Institute, University of California, Irvine, CA 92612 (United States); Zhang Rong [Beckman Laser Institute, University of California, Irvine, CA 92612 (United States); Choi, Bernard [Beckman Laser Institute, University of California, Irvine, CA 92612 (United States); Lucassen, Gerald [Personal Care Institute, Philips Research, Prof Holstlaan 4, Eindhoven (Netherlands); Svaasand, Lars O [Department of Physical Electronics Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Nelson, J Stuart [Beckman Laser Institute, University of California, Irvine, CA 92612 (United States)

    2005-01-07

    The diffuse reflectance spectrum of human skin in the visible region (400-800 nm) contains information on the concentrations of chromophores such as melanin and haemoglobin. This information may be extracted by fitting the reflectance spectrum with an optical diffusion based analytical expression applied to a layered skin model. With the use of the analytical expression, it is assumed that light transport is dominated by scattering. For port wine stain (PWS) and highly pigmented human skin, however, this assumption may not be valid resulting in a potentially large error in visual reflectance spectroscopy (VRS). Monte Carlo based techniques can overcome this problem but are currently too computationally intensive to be combined with previously used fitting procedures. The fitting procedure presented herein is based on a library search which enables the use of accurate reflectance spectra based on forward Monte Carlo simulations or diffusion theory. This allows for accurate VRS to characterize chromophore concentrations in PWS and highly pigmented human skin. The method is demonstrated using both simulated and measured reflectance spectra. An additional advantage of the method is that the fitting procedure is very fast.

  17. A library based fitting method for visual reflectance spectroscopy of human skin

    International Nuclear Information System (INIS)

    Verkruysse, Wim; Zhang Rong; Choi, Bernard; Lucassen, Gerald; Svaasand, Lars O; Nelson, J Stuart

    2005-01-01

    The diffuse reflectance spectrum of human skin in the visible region (400-800 nm) contains information on the concentrations of chromophores such as melanin and haemoglobin. This information may be extracted by fitting the reflectance spectrum with an optical diffusion based analytical expression applied to a layered skin model. With the use of the analytical expression, it is assumed that light transport is dominated by scattering. For port wine stain (PWS) and highly pigmented human skin, however, this assumption may not be valid resulting in a potentially large error in visual reflectance spectroscopy (VRS). Monte Carlo based techniques can overcome this problem but are currently too computationally intensive to be combined with previously used fitting procedures. The fitting procedure presented herein is based on a library search which enables the use of accurate reflectance spectra based on forward Monte Carlo simulations or diffusion theory. This allows for accurate VRS to characterize chromophore concentrations in PWS and highly pigmented human skin. The method is demonstrated using both simulated and measured reflectance spectra. An additional advantage of the method is that the fitting procedure is very fast

  18. A library based fitting method for visual reflectance spectroscopy of human skin

    Science.gov (United States)

    Verkruysse, Wim; Zhang, Rong; Choi, Bernard; Lucassen, Gerald; Svaasand, Lars O.; Nelson, J. Stuart

    2005-01-01

    The diffuse reflectance spectrum of human skin in the visible region (400-800 nm) contains information on the concentrations of chromophores such as melanin and haemoglobin. This information may be extracted by fitting the reflectance spectrum with an optical diffusion based analytical expression applied to a layered skin model. With the use of the analytical expression, it is assumed that light transport is dominated by scattering. For port wine stain (PWS) and highly pigmented human skin, however, this assumption may not be valid resulting in a potentially large error in visual reflectance spectroscopy (VRS). Monte Carlo based techniques can overcome this problem but are currently too computationally intensive to be combined with previously used fitting procedures. The fitting procedure presented herein is based on a library search which enables the use of accurate reflectance spectra based on forward Monte Carlo simulations or diffusion theory. This allows for accurate VRS to characterize chromophore concentrations in PWS and highly pigmented human skin. The method is demonstrated using both simulated and measured reflectance spectra. An additional advantage of the method is that the fitting procedure is very fast.

  19. Non-animal assessment of skin sensitization hazard: Is an integrated testing strategy needed, and if so what should be integrated?

    Science.gov (United States)

    Roberts, David W; Patlewicz, Grace

    2018-01-01

    There is an expectation that to meet regulatory requirements, and avoid or minimize animal testing, integrated approaches to testing and assessment will be needed that rely on assays representing key events (KEs) in the skin sensitization adverse outcome pathway. Three non-animal assays have been formally validated and regulatory adopted: the direct peptide reactivity assay (DPRA), the KeratinoSens™ assay and the human cell line activation test (h-CLAT). There have been many efforts to develop integrated approaches to testing and assessment with the "two out of three" approach attracting much attention. Here a set of 271 chemicals with mouse, human and non-animal sensitization test data was evaluated to compare the predictive performances of the three individual non-animal assays, their binary combinations and the "two out of three" approach in predicting skin sensitization potential. The most predictive approach was to use both the DPRA and h-CLAT as follows: (1) perform DPRA - if positive, classify as sensitizing, and (2) if negative, perform h-CLAT - a positive outcome denotes a sensitizer, a negative, a non-sensitizer. With this approach, 85% (local lymph node assay) and 93% (human) of non-sensitizer predictions were correct, whereas the "two out of three" approach had 69% (local lymph node assay) and 79% (human) of non-sensitizer predictions correct. The findings are consistent with the argument, supported by published quantitative mechanistic models that only the first KE needs to be modeled. All three assays model this KE to an extent. The value of using more than one assay depends on how the different assays compensate for each other's technical limitations. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  20. In vitro assessment of skin irritation potential of surfactant-based formulations by using a 3-D skin reconstructed tissue model and cytokine response.

    Science.gov (United States)

    Walters, Russel M; Gandolfi, Lisa; Mack, M Catherine; Fevola, Michael; Martin, Katharine; Hamilton, Mathew T; Hilberer, Allison; Barnes, Nicole; Wilt, Nathan; Nash, Jennifer R; Raabe, Hans A; Costin, Gertrude-Emilia

    2016-12-01

    The personal care industry is focused on developing safe, more efficacious, and increasingly milder products, that are routinely undergoing preclinical and clinical testing before becoming available for consumer use on skin. In vitro systems based on skin reconstructed equivalents are now established for the preclinical assessment of product irritation potential and as alternative testing methods to the classic Draize rabbit skin irritation test. We have used the 3-D EpiDerm™ model system to evaluate tissue viability and primary cytokine interleukin-1α release as a way to evaluate the potential dermal irritation of 224 non-ionic, amphoteric and/or anionic surfactant-containing formulations, or individual raw materials. As part of our testing programme, two representative benchmark materials with known clinical skin irritation potential were qualified through repeated testing, for use as references for the skin irritation evaluation of formulations containing new surfactant ingredients. We have established a correlation between the in vitro screening approach and clinical testing, and are continually expanding our database to enhance this correlation. This testing programme integrates the efforts of global manufacturers of personal care products that focus on the development of increasingly milder formulations to be applied to the skin, without the use of animal testing. 2016 FRAME.

  1. Illuminant color estimation based on pigmentation separation from human skin color

    Science.gov (United States)

    Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

    2015-03-01

    Human has the visual system called "color constancy" that maintains the perceptive colors of same object across various light sources. The effective method of color constancy algorithm was proposed to use the human facial color in a digital color image, however, this method has wrong estimation results by the difference of individual facial colors. In this paper, we present the novel color constancy algorithm based on skin color analysis. The skin color analysis is the method to separate the skin color into the components of melanin, hemoglobin and shading. We use the stationary property of Japanese facial color, and this property is calculated from the components of melanin and hemoglobin. As a result, we achieve to propose the method to use subject's facial color in image and not depend on the individual difference among Japanese facial color.

  2. Noninvasive spectral imaging of skin chromophores based on multiple regression analysis aided by Monte Carlo simulation

    Science.gov (United States)

    Nishidate, Izumi; Wiswadarma, Aditya; Hase, Yota; Tanaka, Noriyuki; Maeda, Takaaki; Niizeki, Kyuichi; Aizu, Yoshihisa

    2011-08-01

    In order to visualize melanin and blood concentrations and oxygen saturation in human skin tissue, a simple imaging technique based on multispectral diffuse reflectance images acquired at six wavelengths (500, 520, 540, 560, 580 and 600nm) was developed. The technique utilizes multiple regression analysis aided by Monte Carlo simulation for diffuse reflectance spectra. Using the absorbance spectrum as a response variable and the extinction coefficients of melanin, oxygenated hemoglobin, and deoxygenated hemoglobin as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of melanin and total blood are then determined from the regression coefficients using conversion vectors that are deduced numerically in advance, while oxygen saturation is obtained directly from the regression coefficients. Experiments with a tissue-like agar gel phantom validated the method. In vivo experiments with human skin of the human hand during upper limb occlusion and of the inner forearm exposed to UV irradiation demonstrated the ability of the method to evaluate physiological reactions of human skin tissue.

  3. Enhancing Skin Permeation of Biphenylacetic Acid (BPA) Using Salt Formation with Organic and Alkali Metal Bases.

    Science.gov (United States)

    Pawar, Vijay; Naik, Prashant; Giridhar, Rajani; Yadav, Mange Ram

    2015-01-01

    In the present study, a series of organic and alkali metal salts of biphenylacetic acid (BPA) have been prepared and evaluated in vitro for percutaneous drug delivery. The physicochemical properties of BPA salts were determined using solubility measurements, DSC, and IR. The DSC thermogram and FTIR spectra confirmed the salt formation with organic and alkali metal bases. Among the series, salts with organic amines (ethanolamine, diethanolamine, triethanolamine, and diethylamine) had lowered melting points while the alkali metal salt (sodium) had a higher melting point than BPA. The in vitro study showed that salt formation improves the physicochemical properties of BPA, leading to improved permeability through the skin. Amongst all the prepared salts, ethanolamine salt (1b) showed 7.2- and 5.4-fold higher skin permeation than the parent drug at pH 7.4 and 5.0, respectively, using rat skin.

  4. Dithiafulvene-based organic sensitizers using pyridine as the acceptor for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jun; Cao, Yaxiong; Liang, Xiaozhong; Zheng, Jingxia; Zhang, Fang [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Wei, Shuxian; Lu, Xiaoqing [College of Science, China University of Petroleum, Qingdao, Shandong 266555 (China); Guo, Kunpeng, E-mail: guokunpeng@tyut.edu.cn [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Yang, Shihe, E-mail: chsyang@ust.hk [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

    2017-05-01

    Three dithiafulvene-based metal-free organic sensitizers all using pyridine as the acceptor but with different π-bridges of phenyl (DTF-Py1), thienyl (DTF-Py2) and phenyl-thienyl (DTF-Py3) have been designed, synthesized and used as photosensitizers for dye-sensitized solar cells (DSCs). Introducing thienyl unit into the π-bridge, as well as extension of the π-bridge can dramatically improve their light harvesting ability and suppress the electron recombination, thus uplifting the performance of DSCs. The overall power conversion efficiency of DSC based on DTF-Py3 shows the highest efficiency of 2.61% with a short-circuit photocurrent density of 7.99 mA cm{sup -2}, an open-circuit photovoltage of 630 mV, and a fill factor of 0.52, under standard global AM 1.5 solar light condition. More importantly, the long-term stability of the DTF-Py3 based DSCs under 500 h light-soaking has been demonstrated. - Highlights: • Dithiafulvene sensitizers using pyridine ring as the acceptor were synthesized for the first time. • The power conversion efficiency of 2.61% was obtained for DTF-Py3 sensitized cell. • DTF-Py3 loaded TiO{sub 2} film shows improved light harvesting ability and suppressed electron recombination.

  5. Continuous integration congestion cost allocation based on sensitivity

    International Nuclear Information System (INIS)

    Wu, Z.Q.; Wang, Y.N.

    2004-01-01

    Congestion cost allocation is a very important topic in congestion management. Allocation methods based on the Aumann-Shapley value use the discrete numerical integration method, which needs to solve the incremented OPF solution many times, and as such it is not suitable for practical application to large-scale systems. The optimal solution and its sensitivity change tendency during congestion removal using a DC optimal power flow (OPF) process is analysed. A simple continuous integration method based on the sensitivity is proposed for the congestion cost allocation. The proposed sensitivity analysis method needs a smaller computation time than the method based on using the quadratic method and inner point iteration. The proposed congestion cost allocation method uses a continuous integration method rather than discrete numerical integration. The method does not need to solve the incremented OPF solutions; which allows it use in large-scale systems. The method can also be used for AC OPF congestion management. (author)

  6. Chimeric superficial temporal artery based skin and temporal fascia flap plus temporalis muscle flap - An alternative to free flap for suprastructure maxillectomy with external skin defect

    Directory of Open Access Journals (Sweden)

    Dushyant Jaiswal

    2011-01-01

    Full Text Available Flaps from temporal region have been used for mid face, orbital and peri-orbital reconstruction. The knowledge of the vascular anatomy of the region helps to dissect and harvest the muscle/fascia/skin/combined tissue flaps from that region depending upon the requirement. Suprastructure maxillectomy defects are usually covered with free flaps to fill the cavity. Here we report an innovative idea in which a patient with a supra structure maxillectomy with external skin defect was covered with chimeric flap based on the parietal and frontal branches of superficial temporal artery and the temporalis muscle flap based on deep temporal artery.

  7. Oily skin: specific features in Chinese women.

    Science.gov (United States)

    Nouveau-Richard, S; Zhu, W; Li, Y H; Zhang, Y Z; Yang, F Z; Yang, Z L; Lian, S; Qian, B Y; Ran, Y P; Bouillon, C; Chen, H D; de Lacharrière, O

    2007-02-01

    Inconsistent data are available on the various types of skin, their prevalence and characterization, particularly regarding Asian skins. This observation prompted to conduct a large study in China to assess the prevalence of oily skin and identify the specific factors related to that type of skin. The multicentre trial involved 1787 Chinese women in Shenyang, Harbin, Beijing, Chengdu and Suzhou, between 18 and 65 years of age. Data on history of acne, the presence of environmental factors and a detailed self-evaluation of the skin were collected using a standardized questionnaire. A clinical evaluation of facial skin oiliness was carried-out by a dermatologist at each centre. Sebum secretion was measured on the forehead using Sebumeter SM810. Statistical analysis (multiple correspondence analysis) of typology was conducted based on self-evaluation data. According to self-evaluation data, oily skin prevalence in the overall Chinese population of the study was 25.6%. Self-evaluation results were quite consistent with sebum measurements and with clinical assessment by dermatologist. Parameters associated with oily skin were (i) shiny skin and a past history of acne, (ii) irregular menstruation, and (iii) highly reactive or sensitive skin. Moreover, a clear and significant link was noted between oily skin and the ingestion of spicy or sweet food. Lastly, sebum levels were found to be twice as high in Beijing as in the other cities and were correlated to higher oily skin prevalence. The study demonstrated the capacity of women for proper self-evaluation of their skin type. It also suggests a potential link between nutritional factors such as spicy and/or sweet diets and oily skin as well as between sensitive and oily skin in this population.

  8. Cloud-based Monte Carlo modelling of BSSRDF for the rendering of human skin appearance (Conference Presentation)

    Science.gov (United States)

    Doronin, Alexander; Rushmeier, Holly E.; Meglinski, Igor; Bykov, Alexander V.

    2016-03-01

    We present a new Monte Carlo based approach for the modelling of Bidirectional Scattering-Surface Reflectance Distribution Function (BSSRDF) for accurate rendering of human skin appearance. The variations of both skin tissues structure and the major chromophores are taken into account correspondingly to the different ethnic and age groups. The computational solution utilizes HTML5, accelerated by the graphics processing units (GPUs), and therefore is convenient for the practical use at the most of modern computer-based devices and operating systems. The results of imitation of human skin reflectance spectra, corresponding skin colours and examples of 3D faces rendering are presented and compared with the results of phantom studies.

  9. Skin sensitization potency of methyl methacrylate in the local lymph node assay: comparisons with guinea-pig data and human experience.

    Science.gov (United States)

    Betts, Catherine J; Dearman, Rebecca J; Heylings, Jon R; Kimber, Ian; Basketter, David A

    2006-09-01

    There is compelling evidence that contact allergens differ substantially (by 4 or 5 orders of magnitude) with respect to their inherent skin-sensitizing potency. Relative potency can now be measured effectively using the mouse local lymph node assay (LLNA) and such data form the basis of risk assessment and risk management strategies. Such determinations also facilitate distinctions being drawn between the prevalence of skin sensitization to a particular contact allergen and inherent potency. The distinction is important because chemicals that are implicated as common causes of contact allergy are not necessarily potent sensitizers. One example is provided by nickel that is undoubtedly a common cause of allergic contact dermatitis, but is a comparatively weak sensitizer in predictive tests. In an attempt to explore other examples of contact allergens where there may exist a discrepancy between prevalence and potency, we describe here analyses conducted with methyl methacrylate (MMA). Results of LLNA studies have been interpreted in the context of historical clinical data on occupational allergic contact dermatitis associated with exposure to MMA.

  10. An in vitro test to screen skin sensitizers using a stable THP-1-derived IL-8 reporter cell line, THP-G8.

    Science.gov (United States)

    Takahashi, Toshiya; Kimura, Yutaka; Saito, Rumiko; Nakajima, Yoshihiro; Ohmiya, Yoshihiro; Yamasaki, Kenshi; Aiba, Setsuya

    2011-12-01

    Several studies have suggested that interleukin (IL)-8 can serve as a biomarker for discrimination of skin sensitizers from nonsensitizers. We established a stable THP-1-derived IL-8 reporter cell line, THP-G8, which harbors SLO and SLR luciferase genes under the control of IL-8 and glyceraldehyde 3-phosphate dehydrogenase promoters, respectively. After 6 h treatment with chemicals, normalized SLO luciferase activity (nSLO-LA) was calculated by dividing SLO-LA by SLR-LA, and the fold induction of nSLO-LA (FInSLO-LA) was calculated by dividing nSLO-LA of chemically treated cells by that of nontreated cells. The nSLO-LA of THP-G8 cells increased in response to lipopolysaccharide (LPS) and several sensitizers. The FInSLO-LA in THP-G8 cells induced by LPS or sensitizers positively correlated with their induction of IL-8 messenger RNA in THP-1 cells. The nSLO-LA value of THP-G8 cells was significantly increased (FInSLO-LA ≥ 1.4) by 13 of the 15 sensitizers as well as by 5 of the 7 nonsensitizers. Interestingly, pretreatment with N-acetylcysteine suppressed the increase in FInSLO-LA induced by all sensitizers (inhibition index (II) ≤ 0.8) but did not suppress that induced by most of the nonsensitizers. We then evaluated the performance of this assay using values of FInSLO-LA ≥ 1.4 and II ≤ 0.8 in at least two of three independent experiments as the criteria of a sensitizer, which resulted in test accuracies of 82% for the 22 chemicals used and of 88% for the chemicals proposed by European Center for the Validation of Alternative Methods. This newly developed assay is a candidate replacement for animal tests of skin sensitization because of its accuracy, convenience, and high throughput performance.

  11. Monte Carlo evaluation of derivative-based global sensitivity measures

    Energy Technology Data Exchange (ETDEWEB)

    Kucherenko, S. [Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ (United Kingdom)], E-mail: s.kucherenko@ic.ac.uk; Rodriguez-Fernandez, M. [Process Engineering Group, Instituto de Investigaciones Marinas, Spanish Council for Scientific Research (C.S.I.C.), C/ Eduardo Cabello, 6, 36208 Vigo (Spain); Pantelides, C.; Shah, N. [Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ (United Kingdom)

    2009-07-15

    A novel approach for evaluation of derivative-based global sensitivity measures (DGSM) is presented. It is compared with the Morris and the Sobol' sensitivity indices methods. It is shown that there is a link between DGSM and Sobol' sensitivity indices. DGSM are very easy to implement and evaluate numerically. The computational time required for numerical evaluation of DGSM is many orders of magnitude lower than that for estimation of the Sobol' sensitivity indices. It is also lower than that for the Morris method. Efficiencies of Monte Carlo (MC) and quasi-Monte Carlo (QMC) sampling methods for calculation of DGSM are compared. It is shown that the superiority of QMC over MC depends on the problem's effective dimension, which can also be estimated using DGSM.

  12. Monte Carlo evaluation of derivative-based global sensitivity measures

    International Nuclear Information System (INIS)

    Kucherenko, S.; Rodriguez-Fernandez, M.; Pantelides, C.; Shah, N.

    2009-01-01

    A novel approach for evaluation of derivative-based global sensitivity measures (DGSM) is presented. It is compared with the Morris and the Sobol' sensitivity indices methods. It is shown that there is a link between DGSM and Sobol' sensitivity indices. DGSM are very easy to implement and evaluate numerically. The computational time required for numerical evaluation of DGSM is many orders of magnitude lower than that for estimation of the Sobol' sensitivity indices. It is also lower than that for the Morris method. Efficiencies of Monte Carlo (MC) and quasi-Monte Carlo (QMC) sampling methods for calculation of DGSM are compared. It is shown that the superiority of QMC over MC depends on the problem's effective dimension, which can also be estimated using DGSM.

  13. Use of a smart phone based thermo camera for skin prick allergy testing: a feasibility study (Conference Presentation)

    Science.gov (United States)

    Barla, Lindi; Verdaasdonk, Rudolf M.; Rustemeyer, Thomas; Klaessens, John; van der Veen, Albert

    2016-02-01

    Allergy testing is usually performed by exposing the skin to small quantities of potential allergens on the inner forearm and scratching the protective epidermis to increase exposure. After 15 minutes the dermatologist performs a visual check for swelling and erythema which is subjective and difficult for e.g. dark skin types. A small smart phone based thermo camera (FLIR One) was used to obtain quantitative images in a feasibility study of 17 patients Directly after allergen exposure on the forearm, thermal images were captured at 30 seconds interval and processed to a time lapse movie over 15 minutes. Considering the 'subjective' reading of the dermatologist as golden standard, in 11/17 pts (65%) the evaluation of dermatologist was confirmed by the thermo camera including 5 of 6 patients without allergic response. In 7 patients thermo showed additional spots. Of the 342 sites tested, the dermatologist detected 47 allergies of which 28 (60%) were confirmed by thermo imaging while thermo imaging showed 12 additional spots. The method can be improved with user dedicated acquisition software and better registration between normal and thermal images. The lymphatic reaction seems to shift from the original puncture site. The interpretation of the thermal images is still subjective since collecting quantitative data is difficult due to motion patient during 15 minutes. Although not yet conclusive, thermal imaging shows to be promising to improve the sensitivity and selectivity of allergy testing using a smart phone based camera.

  14. A spectrofluorimetric sensor based on grape skin tissue for determination of iron(III

    Directory of Open Access Journals (Sweden)

    Minghui Zhang

    2010-04-01

    Full Text Available A spectrofluorimetric method based on the grape skin has been developed for the determination of Fe3+ at pH 5.0. The emission wavelength of the grape skin sensor occurs at 680 nm and the excitation wavelength at 421 nm. The fluorescence of sensor could be quenched by Fe3+ due to the complexing ability of anthocyanin with the metal ions. Anthocyanin, the main pigment in the grape skin, has been found fluorescence sensing material. The sensor based on the grape skin exhibited a calibration response for Fe3+ in two concentration ranges of 1.0 × 10-8 - 1.0 × 10-5 M (r2 = 0.9888 and 3.2 × 10-5 - 3.2 × 10-4 (r2 = 0.9856 M at 60 oC. The detection limit was found to be 7.5×10-9 M, and the other common ions did not interfere.

  15. Design and manufacturing of skins based on composite corrugated laminates for morphing aerodynamic surfaces

    Science.gov (United States)

    Airoldi, Alessandro; Fournier, Stephane; Borlandelli, Elena; Bettini, Paolo; Sala, Giuseppe

    2017-04-01

    The paper discusses the approaches for the design and manufacturing of morphing skins based on rectangular-shaped composite corrugated laminates and proposes a novel solution to prevent detrimental effects of corrugation on aerodynamic performances. Additionally, more complex corrugated shapes are presented and analysed. The manufacturing issues related to the production of corrugated laminates are discussed and tests are performed to compare different solutions and to assess the validity of analytical and numerical predictions. The solution presented to develop an aerodynamically efficient skin consists in the integration of an elastomeric cover in the corrugated laminate. The related manufacturing process is presented and assessed, and a fully nonlinear numerical model is developed and characterized to study the behaviour of this skin concept in different load conditions. Finally, configurations based on combinations of individual rectangular-shaped corrugated panels are considered. Their structural properties are numerically investigated by varying geometrical parameters. Performance indices are defined to compare structural stiffness contributions in non-morphing directions with the ones of conventional panels of the same weight. Numerical studies also show that the extension of the concept to complex corrugated shapes may improve both the design flexibility and some specific performances with respect to rectangular shaped corrugations. The overall results validate the design approaches and manufacturing processes to produce corrugated laminates and indicate that the solution for the integration of an elastomeric cover is a feasible and promising method to enhance the aerodynamic efficiency of corrugated skins.

  16. Highly sensitive strain sensors based on fragmentized carbon nanotube/polydimethylsiloxane composites

    Science.gov (United States)

    Gao, Yang; Fang, Xiaoliang; Tan, Jianping; Lu, Ting; Pan, Likun; Xuan, Fuzhen

    2018-06-01

    Wearable strain sensors based on nanomaterial/elastomer composites have potential applications in flexible electronic skin, human motion detection, human–machine interfaces, etc. In this research, a type of high performance strain sensors has been developed using fragmentized carbon nanotube/polydimethylsiloxane (CNT/PDMS) composites. The CNT/PDMS composites were ground into fragments, and a liquid-induced densification method was used to fabricate the strain sensors. The strain sensors showed high sensitivity with gauge factors (GFs) larger than 200 and a broad strain detection range up to 80%, much higher than those strain sensors based on unfragmentized CNT/PDMS composites (GF composite particles during mechanical deformation, which causes significant resistance change in the strain sensors. The strain sensors can differentiate mechanical stimuli and monitor various human body motions, such as bending of the fingers, human breathing, and blood pulsing.

  17. Highly sensitive strain sensors based on fragmentized carbon nanotube/polydimethylsiloxane composites.

    Science.gov (United States)

    Gao, Yang; Fang, Xiaoliang; Tan, Jianping; Lu, Ting; Pan, Likun; Xuan, Fuzhen

    2018-06-08

    Wearable strain sensors based on nanomaterial/elastomer composites have potential applications in flexible electronic skin, human motion detection, human-machine interfaces, etc. In this research, a type of high performance strain sensors has been developed using fragmentized carbon nanotube/polydimethylsiloxane (CNT/PDMS) composites. The CNT/PDMS composites were ground into fragments, and a liquid-induced densification method was used to fabricate the strain sensors. The strain sensors showed high sensitivity with gauge factors (GFs) larger than 200 and a broad strain detection range up to 80%, much higher than those strain sensors based on unfragmentized CNT/PDMS composites (GF sensors is ascribed to the sliding of individual fragmentized-CNT/PDMS-composite particles during mechanical deformation, which causes significant resistance change in the strain sensors. The strain sensors can differentiate mechanical stimuli and monitor various human body motions, such as bending of the fingers, human breathing, and blood pulsing.

  18. Differential Search Coils Based Magnetometers: Conditioning, Magnetic Sensitivity, Spatial Resolution

    Directory of Open Access Journals (Sweden)

    Timofeeva Maria

    2012-03-01

    Full Text Available A theoretical and experimental comparison of optimized search coils based magnetometers, operating either in the Flux mode or in the classical Lenz-Faraday mode, is presented. The improvements provided by the Flux mode in terms of bandwidth and measuring range of the sensor are detailed. Theory, SPICE model and measurements are in good agreement. The spatial resolution of the sensor is studied which is an important parameter for applications in non destructive evaluation. A general expression of the magnetic sensitivity of search coils sensors is derived. Solutions are proposed to design magnetometers with reduced weight and volume without degrading the magnetic sensitivity. An original differential search coil based magnetometer, made of coupled coils, operating in flux mode and connected to a differential transimpedance amplifier is proposed. It is shown that this structure is better in terms of volume occupancy than magnetometers using two separated coils without any degradation in magnetic sensitivity. Experimental results are in good agreement with calculations.

  19. A high sensitivity nanomaterial based SAW humidity sensor

    Energy Technology Data Exchange (ETDEWEB)

    Wu, T-T; Chou, T-H [Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan (China); Chen, Y-Y [Department of Mechanical Engineering, Tatung University, Taipei 104, Taiwan (China)], E-mail: wutt@ndt.iam.ntu.edu.tw

    2008-04-21

    In this paper, a highly sensitive humidity sensor is reported. The humidity sensor is configured by a 128{sup 0}YX-LiNbO{sub 3} based surface acoustic wave (SAW) resonator whose operating frequency is at 145 MHz. A dual delay line configuration is realized to eliminate external temperature fluctuations. Moreover, for nanostructured materials possessing high surface-to-volume ratio, large penetration depth and fast charge diffusion rate, camphor sulfonic acid doped polyaniline (PANI) nanofibres are synthesized by the interfacial polymerization method and further deposited on the SAW resonator as selective coating to enhance sensitivity. The humidity sensor is used to measure various relative humidities in the range 5-90% at room temperature. Results show that the PANI nanofibre based SAW humidity sensor exhibits excellent sensitivity and short-term repeatability.

  20. Sensitizing Clostridium difficile Spores With Germinants on Skin and Environmental Surfaces Represents a New Strategy for Reducing Spores via Ambient Mechanisms

    Directory of Open Access Journals (Sweden)

    Michelle Marie Nerandzic

    2017-10-01

    Full Text Available Background: Clostridium difficile is a leading cause of healthcare-associated infections worldwide. Prevention of C. difficile transmission is challenging because spores are not killed by alcohol-based hand sanitizers or many commonly used disinfectants. One strategy to control spores is to induce germination, thereby rendering the spores more susceptible to benign disinfection measures and ambient stressors. Methods/Results: C. difficile spores germinated on skin after a single application of cholic acid-class bile salts and co-germinants; for 4 C. difficile strains, recovery of viable spores from skin was reduced by ~0.3 log10CFU to 2 log10CFU after 2 hours and ~1 log10CFU to >2.5 log 10CFU after 24 hours. The addition of taurocholic acid to 70% and 30% ethanol significantly enhanced reduction of viable spores on skin and on surfaces. Desiccation, and to a lesser extent the presence of oxygen, were identified as the stressors responsible for reductions of germinated spores on skin and surfaces. Additionally, germinated spores became susceptible to killing by pH 1.5 hydrochloric acid, suggesting that germinated spores that remain viable on skin and surfaces might be killed by gastric acid after ingestion. Antibiotic-treated mice did not become colonized after exposure to germinated spores, whereas 100% of mice became colonized after exposure to the same quantity of dormant spores. Conclusions: Germination could provide a new approach to reduce C. difficile spores on skin and in the environment and to render surviving spores less capable of causing infection. Our findings suggest that it may be feasible to develop alcohol-based hand sanitizers containing germinants that reduce spores on hands.

  1. Sensitivity-based research prioritization through stochastic characterization modeling

    DEFF Research Database (Denmark)

    Wender, Ben A.; Prado-Lopez, Valentina; Fantke, Peter

    2018-01-01

    to guide research efforts in data refinement and design of experiments for existing and emerging chemicals alike. This study presents a sensitivity-based approach for estimating toxicity characterization factors given high input data uncertainty and using the results to prioritize data collection according...

  2. Examining Appearance-Based Rejection Sensitivity during Early Adolescence

    Science.gov (United States)

    Bowker, Julie C.; Thomas, Katelyn K.; Spencer, Sarah V.; Park, Lora E.

    2013-01-01

    The present study of 150 adolescents ("M" age = 13.05 years) examined the associations between appearance-based rejection sensitivity (Appearance-RS) and psychological adjustment during early adolescence, and evaluated three types of other-gender peer experiences (other-gender friendship, peer acceptance, and romantic relationships) as…

  3. Content sensitivity based access control framework for Hadoop

    Directory of Open Access Journals (Sweden)

    T.K. Ashwin Kumar

    2017-11-01

    Full Text Available Big data technologies have seen tremendous growth in recent years. They are widely used in both industry and academia. In spite of such exponential growth, these technologies lack adequate measures to protect data from misuse/abuse. Corporations that collect data from multiple sources are at risk of liabilities due to the exposure of sensitive information. In the current implementation of Hadoop, only file-level access control is feasible. Providing users with the ability to access data based on the attributes in a dataset or the user’s role is complicated because of the sheer volume and multiple formats (structured, unstructured and semi-structured of data. In this paper, we propose an access control framework, which enforces access control policies dynamically based on the sensitivity of the data. This framework enforces access control policies by harnessing the data context, usage patterns and information sensitivity. Information sensitivity changes over time with the addition and removal of datasets, which can lead to modifications in access control decisions. The proposed framework accommodates these changes. The proposed framework is automated to a large extent as the data itself determines the sensitivity with minimal user intervention. Our experimental results show that the proposed framework is capable of enforcing access control policies on non-multimedia datasets with minimal overhead.

  4. Application of water-soluble polyvinyl alcohol-based film patches on laser microporated skin facilitates intradermal macromolecule and nanoparticle delivery.

    Science.gov (United States)

    Engelke, Laura; Winter, Gerhard; Engert, Julia

    2018-07-01

    The intradermal delivery of biologics has long been recognized as attractive approach for cutaneous immunotherapy, particularly vaccination. Although intradermal (i.d.) or subcutaneous (s.c.) injection provide reproducible dosing and good cost- and delivery efficiency, the major objective to avoid sharps and the need for enhanced storage stability have renewed the interest in alternative needle-free delivery strategies. This study presents a new concept for the delivery of macromolecules and nanoparticles to viable skin layers with a high density of professional antigen-presenting cells (APCs). Stable polyvinyl alcohol (PVA) polymer films as well as PVA blends with carboxymethyl cellulose (CMC) or cross-linked carbomer were prepared using an easily-scalable film casting technique. Fluorescein isothiocyanate (FITC) and rhodamine B-labeled dextrane 70 kDa (RD70), used as small and macromolecular model substances, or polystyrene (PS)-nano- and microparticles with diameters of 0.5 µm and 5 µm were directly incorporated into the polymer formulations at varying concentrations. The assembly of the polymer films with an occlusive backing tape created a film patch that provided a fast drug release upon dissolution of the water-soluble film and facilitated an intradermal drug delivery on laser microporated skin. The minimally-invasive P.L.E.A.S.E.® laser poration system (Pantec Biosolutions, Ruggell, Liechtenstein) provided access to viable skin layers by thermally ablating the superficial tissue with a pulsed Er:YAG laser (λ = 2.94 µm). In our in vitro study using excised pig skin, laser microporation induced a 4- to 5-fold increase of water transport (TEWL) through excised skin in a Franz diffusion cell compared to intact skin. The TEWL values detected were comparable to in vivo human skin. The increased water transport facilitated the dissolution of all topically applied dry PVA-based film formulations within 6 h. No dissolution of the films was seen on

  5. Real-Time Digital Signal Processing Based on FPGAs for Electronic Skin Implementation †

    Directory of Open Access Journals (Sweden)

    Ali Ibrahim

    2017-03-01

    Full Text Available Enabling touch-sensing capability would help appliances understand interaction behaviors with their surroundings. Many recent studies are focusing on the development of electronic skin because of its necessity in various application domains, namely autonomous artificial intelligence (e.g., robots, biomedical instrumentation, and replacement prosthetic devices. An essential task of the electronic skin system is to locally process the tactile data and send structured information either to mimic human skin or to respond to the application demands. The electronic skin must be fabricated together with an embedded electronic system which has the role of acquiring the tactile data, processing, and extracting structured information. On the other hand, processing tactile data requires efficient methods to extract meaningful information from raw sensor data. Machine learning represents an effective method for data analysis in many domains: it has recently demonstrated its effectiveness in processing tactile sensor data. In this framework, this paper presents the implementation of digital signal processing based on FPGAs for tactile data processing. It provides the implementation of a tensorial kernel function for a machine learning approach. Implementation results are assessed by highlighting the FPGA resource utilization and power consumption. Results demonstrate the feasibility of the proposed implementation when real-time classification of input touch modalities are targeted.

  6. A Preliminary Test for Skin Gas Assessment Using a Porphyrin Based Evanescent Wave Optical Fiber Sensor

    Directory of Open Access Journals (Sweden)

    Roman SELYANCHYN

    2011-02-01

    Full Text Available An evanescent-wave optical fibre sensor modified with tetrakis-(4-sulfophenyl porphine (TSPP and poly(allylamine hydrochloride (PAH bilayers using layer-by-layer (LbL electrostatic self-assembly was tested to measure the gas emitted from human skin. Optical intensity changes at different wavelengths in the transmission spectrum of the porphyrin-based film were induced by the human skin gas and measured as sensor response. Influence of relative humidity, which can be a major interference to sensor response, was thoroughly studied and shown to be significantly different when compared to the influence of skin emanations. Responses of the current optical sensor system could be considered as composite sensor array, where different optical wavelengths act as channels that have selective response to specific volatile compounds. Data obtained from the sensor system was analyzed using principal component analysis (PCA. This approach enabled to distinguish skin odors of different people and their altered physiological conditions after alcohol consumption.

  7. Obsessive-compulsive skin disorders: a novel classification based on degree of insight.

    Science.gov (United States)

    Zhu, Tian Hao; Nakamura, Mio; Farahnik, Benjamin; Abrouk, Michael; Reichenberg, Jason; Bhutani, Tina; Koo, John

    2017-06-01

    Individuals with obsessive-compulsive features frequently visit dermatologists for complaints of the skin, hair or nails, and often progress towards a chronic relapsing course due to the challenge associated with accurate diagnosis and management of their psychiatric symptoms. The current DSM-5 formally recognizes body dysmorphic disorder, trichotillomania, neurotic excoriation and body focused repetitive behavior disorder as psychodermatological disorders belonging to the category of Obsessive-Compulsive and Related Disorders. However there is evidence that other relevant skin diseases such as delusions of parasitosis, dermatitis artefacta, contamination dermatitis, AIDS phobia, trichotemnomania and even lichen simplex chronicus possess prominent obsessive-compulsive characteristics that do not necessarily fit the full diagnostic criteria of the DSM-5. Therefore, to increase dermatologists' awareness of this unique group of skin disorders with OCD features, we propose a novel classification system called Obsessive-Compulsive Insight Continuum. Under this new classification system, obsessive-compulsive skin manifestations are categorized along a continuum based on degree of insight, from minimal insight with delusional obsessions to good insight with minimal obsessions. Understanding the level of insight is thus an important first step for clinicians who routinely interact with these patients.

  8. Transfer of a two-tiered keratinocyte assay: IL-18 production by NCTC2544 to determine the skin sensitizing capacity and epidermal equivalent assay to determine sensitizer potency

    NARCIS (Netherlands)

    Teunis, M.; Corsini, E.; Smits, M.; Madsen, C.B.; Eltze, T.; Ezendam, J.; Galbiati, V.; Gremmer, E.; Krul, C.A.M.; Landin, A.; Landsiedel, R.; Pieters, R.; Rasmussen, T.F.; Reinders, J.; Roggen, E.; Spiekstra, S.; Gibbs, S.

    2013-01-01

    At present, the identification of potentially sensitizing chemicals is carried out using animal models. However, it is very important from ethical, safety and economic point of view to have biological markers to discriminate allergy and irritation events, and to be able to classify sensitizers

  9. Skin graft

    Science.gov (United States)

    Skin transplant; Skin autografting; FTSG; STSG; Split thickness skin graft; Full thickness skin graft ... donor site. Most people who are having a skin graft have a split-thickness skin graft. This takes ...

  10. Skin autofluorescence based decision tree in detection of impaired glucose tolerance and diabetes.

    Directory of Open Access Journals (Sweden)

    Andries J Smit

    Full Text Available Diabetes (DM and impaired glucose tolerance (IGT detection are conventionally based on glycemic criteria. Skin autofluorescence (SAF is a noninvasive proxy of tissue accumulation of advanced glycation endproducts (AGE which are considered to be a carrier of glycometabolic memory. We compared SAF and a SAF-based decision tree (SAF-DM with fasting plasma glucose (FPG and HbA1c, and additionally with the Finnish Diabetes Risk Score (FINDRISC questionnaire±FPG for detection of oral glucose tolerance test (OGTT- or HbA1c-defined IGT and diabetes in intermediate risk persons.Participants had ≥1 metabolic syndrome criteria. They underwent an OGTT, HbA1c, SAF and FINDRISC, in adition to SAF-DM which includes SAF, age, BMI, and conditional questions on DM family history, antihypertensives, renal or cardiovascular disease events (CVE.218 persons, age 56 yr, 128M/90F, 97 with previous CVE, participated. With OGTT 28 had DM, 46 IGT, 41 impaired fasting glucose, 103 normal glucose tolerance. SAF alone revealed 23 false positives (FP, 34 false negatives (FN (sensitivity (S 68%; specificity (SP 86%. With SAF-DM, FP were reduced to 18, FN to 16 (5 with DM (S 82%; SP 89%. HbA1c scored 48 FP, 18 FN (S 80%; SP 75%. Using HbA1c-defined DM-IGT/suspicion ≥6%/42 mmol/mol, SAF-DM scored 33 FP, 24 FN (4 DM (S76%; SP72%, FPG 29 FP, 41 FN (S71%; SP80%. FINDRISC≥10 points as detection of HbA1c-based diabetes/suspicion scored 79 FP, 23 FN (S 69%; SP 45%.SAF-DM is superior to FPG and non-inferior to HbA1c to detect diabetes/IGT in intermediate-risk persons. SAF-DM's value for diabetes/IGT screening is further supported by its established performance in predicting diabetic complications.

  11. An improved strategy for skin lesion detection and classification using uniform segmentation and feature selection based approach.

    Science.gov (United States)

    Nasir, Muhammad; Attique Khan, Muhammad; Sharif, Muhammad; Lali, Ikram Ullah; Saba, Tanzila; Iqbal, Tassawar

    2018-02-21

    Melanoma is the deadliest type of skin cancer with highest mortality rate. However, the annihilation in early stage implies a high survival rate therefore, it demands early diagnosis. The accustomed diagnosis methods are costly and cumbersome due to the involvement of experienced experts as well as the requirements for highly equipped environment. The recent advancements in computerized solutions for these diagnoses are highly promising with improved accuracy and efficiency. In this article, we proposed a method for the classification of melanoma and benign skin lesions. Our approach integrates preprocessing, lesion segmentation, features extraction, features selection, and classification. Preprocessing is executed in the context of hair removal by DullRazor, whereas lesion texture and color information are utilized to enhance the lesion contrast. In lesion segmentation, a hybrid technique has been implemented and results are fused using additive law of probability. Serial based method is applied subsequently that extracts and fuses the traits such as color, texture, and HOG (shape). The fused features are selected afterwards by implementing a novel Boltzman Entropy method. Finally, the selected features are classified by Support Vector Machine. The proposed method is evaluated on publically available data set PH2. Our approach has provided promising results of sensitivity 97.7%, specificity 96.7%, accuracy 97.5%, and F-score 97.5%, which are significantly better than the results of existing methods available on the same data set. The proposed method detects and classifies melanoma significantly good as compared to existing methods. © 2018 Wiley Periodicals, Inc.

  12. Fines Classification Based on Sensitivity to Pore-Fluid Chemistry

    KAUST Repository

    Jang, Junbong

    2015-12-28

    The 75-μm particle size is used to discriminate between fine and coarse grains. Further analysis of fine grains is typically based on the plasticity chart. Whereas pore-fluid-chemistry-dependent soil response is a salient and distinguishing characteristic of fine grains, pore-fluid chemistry is not addressed in current classification systems. Liquid limits obtained with electrically contrasting pore fluids (deionized water, 2-M NaCl brine, and kerosene) are combined to define the soil "electrical sensitivity." Liquid limit and electrical sensitivity can be effectively used to classify fine grains according to their fluid-soil response into no-, low-, intermediate-, or high-plasticity fine grains of low, intermediate, or high electrical sensitivity. The proposed methodology benefits from the accumulated experience with liquid limit in the field and addresses the needs of a broader range of geotechnical engineering problems. © ASCE.

  13. Fines classification based on sensitivity to pore-fluid chemistry

    Science.gov (United States)

    Jang, Junbong; Santamarina, J. Carlos

    2016-01-01

    The 75-μm particle size is used to discriminate between fine and coarse grains. Further analysis of fine grains is typically based on the plasticity chart. Whereas pore-fluid-chemistry-dependent soil response is a salient and distinguishing characteristic of fine grains, pore-fluid chemistry is not addressed in current classification systems. Liquid limits obtained with electrically contrasting pore fluids (deionized water, 2-M NaCl brine, and kerosene) are combined to define the soil “electrical sensitivity.” Liquid limit and electrical sensitivity can be effectively used to classify fine grains according to their fluid-soil response into no-, low-, intermediate-, or high-plasticity fine grains of low, intermediate, or high electrical sensitivity. The proposed methodology benefits from the accumulated experience with liquid limit in the field and addresses the needs of a broader range of geotechnical engineering problems.

  14. Abnormal sensitivity of diploid skin fibroblasts from a family with Gardner's syndrome to the lethal effects of X-irradiation, ultraviolet light and mitomycin-C

    International Nuclear Information System (INIS)

    Little, J.B.; Nove, J.; Weichselbaum, R.R.

    1980-01-01

    Skin fibroblasts isolated from two members of the same family with the cancer-prone disease Gardner's Syndrome (intestinal polyposis, colon cancer, bone and soft tissue tumors) showed enhanced sensitivity to the lethal effects of X-irradiation, ultraviolet light and mitomycin-C. These cells showed no liquid-holding type recovery following UV-irradiation of confluent cultures, but were normal in their capacity for UV-induced unscheduled DNA synthesis. UV survival was not influenced by post-irradiation incubation with caffeine. (orig.)

  15. Generic Reliability-Based Inspection Planning for Fatigue Sensitive Details

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Straub, Daniel; Faber, Michael Havbro

    2005-01-01

    of fatigue sensitive details in fixed offshore steel jacket platforms and FPSO ship structures. Inspection and maintenance activities are planned such that code based requirements to the safety of personnel and environment for the considered structure are fulfilled and at the same time such that the overall......The generic approach for planning of in-service NDT inspections is extended to cover the case where the fatigue load is modified during the design lifetime of the structure. Generic reliability-based inspection planning has been developed as a practical approach to perform inspection planning...... expected costs for design, inspections, repairs and failures are minimized. The method is based on the assumption of “no-finds” of cracks during inspections. Each fatigue sensitive detail is categorized according to their type of details (SN curves), FDF values, RSR values, inspection, repair and failure...

  16. Effect of compression stockings on cutaneous microcirculation: Evaluation based on measurements of the skin thermal conductivity.

    Science.gov (United States)

    Grenier, E; Gehin, C; McAdams, E; Lun, B; Gobin, J-P; Uhl, J-F

    2016-03-01

    To study of the microcirculatory effects of elastic compression stockings. In phlebology, laser Doppler techniques (flux or imaging) are widely used to investigate cutaneous microcirculation. It is a method used to explore microcirculation by detecting blood flow in skin capillaries. Flux and imaging instruments evaluate, non-invasively in real-time, the perfusion of cutaneous micro vessels. Such tools, well known by the vascular community, are not really suitable to our protocol which requires evaluation through the elastic compression stockings fabric. Therefore, we involve another instrument, called the Hematron (developed by Insa-Lyon, Biomedical Sensor Group, Nanotechnologies Institute of Lyon), to investigate the relationship between skin microcirculatory activities and external compression provided by elastic compression stockings. The Hematron measurement principle is based on the monitoring of the skin's thermal conductivity. This clinical study examined a group of 30 female subjects, aged 42 years ±2 years, who suffer from minor symptoms of chronic venous disease, classified as C0s, and C1s (CEAP). The resulting figures show, subsequent to the pressure exerted by elastic compression stockings, an improvement of microcirculatory activities observed in 83% of the subjects, and a decreased effect was detected in the remaining 17%. Among the total population, the global average increase of the skin's microcirculatory activities is evaluated at 7.63% ± 1.80% (p compression stockings has a direct influence on the skin's microcirculation within this female sample group having minor chronic venous insufficiency signs. Further investigations are required for a deeper understanding of the elastic compression stockings effects on the microcirculatory activity in venous diseases at other stages of pathology. © The Author(s) 2014.

  17. Skin Stem Cell Hypotheses and Long Term Clone Survival - Explored Using Agent-based Modelling

    OpenAIRE

    Li, X.; Upadhyay, A.K.; Bullock, A.J.; Dicolandrea, T.; Xu, J.; Binder, R.L.; Robinson, M.K.; Finlay, D.R.; Mills, K.J.; Bascom, C.C.; Kelling, C.K.; Isfort, R.J.; Haycock, J.W.; MacNeil, S.; Smallwood, R.H.

    2013-01-01

    Epithelial renewal in skin is achieved by the constant turnover and differentiation of keratinocytes. Three popular hypotheses have been proposed to explain basal keratinocyte regeneration and epidermal homeostasis: 1) asymmetric division (stem-transit amplifying cell); 2) populational asymmetry (progenitor cell with stochastic fate); and 3) populational asymmetry with stem cells. In this study, we investigated lineage dynamics using these hypotheses with a 3D agent-based model of the epiderm...

  18. A comparison of scaffold-free and scaffold-based reconstructed human skin models as alternatives to animal use.

    Science.gov (United States)

    Kinikoglu, Beste

    2017-12-01

    Tissue engineered full-thickness human skin substitutes have various applications in the clinic and in the laboratory, such as in the treatment of burns or deep skin defects, and as reconstructed human skin models in the safety testing of drugs and cosmetics and in the fundamental study of skin biology and pathology. So far, different approaches have been proposed for the generation of reconstructed skin, each with its own advantages and disadvantages. Here, the classic tissue engineering approach, based on cell-seeded polymeric scaffolds, is compared with the less-studied cell self-assembly approach, where the cells are coaxed to synthesise their own extracellular matrix (ECM). The resulting full-thickness human skin substitutes were analysed by means of histological and immunohistochemical analyses. It was found that both the scaffold-free and the scaffold-based skin equivalents successfully mimicked the functionality and morphology of native skin, with complete epidermal differentiation (as determined by the expression of filaggrin), the presence of a continuous basement membrane expressing collagen VII, and new ECM deposition by dermal fibroblasts. On the other hand, the scaffold-free model had a thicker epidermis and a significantly higher number of Ki67-positive proliferative cells, indicating a higher capacity for self-renewal, as compared to the scaffold-based model. 2017 FRAME.

  19. An extremely sensitive monoboronic acid based fluorescent sensor for glucose

    International Nuclear Information System (INIS)

    Sun Xiangying; Liu Bin; Jiang Yunbao

    2004-01-01

    An extremely sensitive monoboronic acid based fluorescent sensor for glucose was developed. This was carried out by assembling a fluorescent monoboronic acid, 3-aminophenylboronic acid (PBA) indirectly onto gold surface via its electrostatic interaction with cysteine (Cys) that was directly assembled on the gold surface. The formation of self-assembled bilayers (SAB) was confirmed and primarily characterized by cyclic voltammetry and X-ray photoelectron spectra (XPS). The SAB containing PBA was found fluorescent and its fluorescence showed an extremely high sensitivity to the presence of glucose and other monosaccharides such as galactose and fructose with quenching constants at 10 8 M -1 order of magnitude compared to those at 10 2 M -1 in bulk solutions. The quenching constants were found to vary in the order of D-glucose>D-galactose>D-fructose>D-mannose that is different from that in bulk solution which shows the highest binding affinity toward D-fructose and very low sensitivity toward glucose. The reported monoboronic acid based SAB fluorescent sensor showed the highest sensitivity towards glucose with the capacity of detecting saccharides of concentration down to nanomolar level. It was also demonstrated that the fluorescence from PBA/Cys/Au can be easily recovered after each measurement event and therefore also represents a new reusable method for immobilizing reagent in fabricating chemosensors

  20. Environmentally Sensitive Fluorescent Sensors Based on Synthetic Peptides

    Directory of Open Access Journals (Sweden)

    Laurence Choulier

    2010-03-01

    Full Text Available Biosensors allow the direct detection of molecular analytes, by associating a biological receptor with a transducer able to convert the analyte-receptor recognition event into a measurable signal. We review recent work aimed at developing synthetic fluorescent molecular sensors for a variety of analytes, based on peptidic receptors labeled with environmentally sensitive fluorophores. Fluorescent indicators based on synthetic peptides are highly interesting alternatives to protein-based sensors, since they can be synthesized chemically, are stable, and can be easily modified in a site-specific manner for fluorophore coupling and for immobilization on solid supports.

  1. Comparative DNA microarray analysis of human monocyte derived dendritic cells and MUTZ-3 cells exposed to the moderate skin sensitizer cinnamaldehyde

    International Nuclear Information System (INIS)

    Python, Francois; Goebel, Carsten; Aeby, Pierre

    2009-01-01

    The number of studies involved in the development of in vitro skin sensitization tests has increased since the adoption of the EU 7th amendment to the cosmetics directive proposing to ban animal testing for cosmetic ingredients by 2013. Several studies have recently demonstrated that sensitizers induce a relevant up-regulation of activation markers such as CD86, CD54, IL-8 or IL-1β in human myeloid cell lines (e.g., U937, MUTZ-3, THP-1) or in human peripheral blood monocyte-derived dendritic cells (PBMDCs). The present study aimed at the identification of new dendritic cell activation markers in order to further improve the in vitro evaluation of the sensitizing potential of chemicals. We have compared the gene expression profiles of PBMDCs and the human cell line MUTZ-3 after a 24-h exposure to the moderate sensitizer cinnamaldehyde. A list of 80 genes modulated in both cell types was obtained and a set of candidate marker genes was selected for further analysis. Cells were exposed to selected sensitizers and non-sensitizers for 24 h and gene expression was analyzed by quantitative real-time reverse transcriptase-polymerase chain reaction. Results indicated that PIR, TRIM16 and two Nrf2-regulated genes, CES1 and NQO1, are modulated by most sensitizers. Up-regulation of these genes could also be observed in our recently published DC-activation test with U937 cells. Due to their role in DC activation, these new genes may help to further refine the in vitro approaches for the screening of the sensitizing properties of a chemical.

  2. A co-cultured skin model based on cell support membranes

    International Nuclear Information System (INIS)

    Dai, N.-T.; Yeh, M.-K.; Liu, Demeral David; Adams, E.F.; Chiang, C.-H.; Yen, C.-Y.; Shih, C.-M.; Sytwu, H.-K.; Chen, Tim-Mo; Wang, H.-J.; Williamson, M.R.; Coombes, A.G.A.

    2005-01-01

    Tissue engineering of skin based on collagen: PCL biocomposites using a designed co-culture system is reported. The collagen: PCL biocomposites having collagen: PCL (w/w) ratios of 1:4, 1:8, and 1:20 have been proven to be biocompatible materials to support both adult normal human epidermal Keratinocyte (NHEK) and mouse 3T3 fibroblast growth in cell culture, respectively, by Dai, Coombes, et al. in 2004. Films of collagen: PCL biocomposites were prepared using non-crosslinking method by impregnation of lyophilized collagen mats with PCL/dichloromethane solutions followed by solvent evaporation. To mimic the dermal/epidermal structure of skin, the 1:20 collagen: PCL biocomposites were selected for a feasibility study of a designed co-culture technique that would subsequently be used for preparing fibroblast/biocomposite/keratinocyte skin models. A 55.3% increase in cell number was measured in the designed co-culture system when fibroblasts were seeded on both sides of a biocomposite film compared with cell culture on one surface of the biocomposite in the feasibility study. The co-culture of human keratinocytes and 3T3 fibroblasts on each side of the membrane was therefore studied using the same co-culture system by growing keratinocytes on the top surface of membrane for 3 days and 3T3 fibroblasts underneath the membrane for 6 days. Scanning electron microscopy (SEM) and immunohistochemistry assay revealed good cell attachment and proliferation of both human keratinocytes and 3T3 fibroblasts with these two types of cells isolated well on each side of the membrane. Using a modified co-culture technique, a co-cultured skin model presenting a confluent epidermal sheet on one side of the biocomposite film and fibroblasts populated on the other side of the film was developed successfully in co-culture system for 28 days under investigations by SEM and immunohistochemistry assay. Thus, the design of a co-culture system based on 1:20 (w/w) collagen: PCL biocomposite

  3. Multiclass classification for skin cancer profiling based on the integration of heterogeneous gene expression series.

    Science.gov (United States)

    Gálvez, Juan Manuel; Castillo, Daniel; Herrera, Luis Javier; San Román, Belén; Valenzuela, Olga; Ortuño, Francisco Manuel; Rojas, Ignacio

    2018-01-01

    Most of the research studies developed applying microarray technology to the characterization of different pathological states of any disease may fail in reaching statistically significant results. This is largely due to the small repertoire of analysed samples, and to the limitation in the number of states or pathologies usually addressed. Moreover, the influence of potential deviations on the gene expression quantification is usually disregarded. In spite of the continuous changes in omic sciences, reflected for instance in the emergence of new Next-Generation Sequencing-related technologies, the existing availability of a vast amount of gene expression microarray datasets should be properly exploited. Therefore, this work proposes a novel methodological approach involving the integration of several heterogeneous skin cancer series, and a later multiclass classifier design. This approach is thus a way to provide the clinicians with an intelligent diagnosis support tool based on the use of a robust set of selected biomarkers, which simultaneously distinguishes among different cancer-related skin states. To achieve this, a multi-platform combination of microarray datasets from Affymetrix and Illumina manufacturers was carried out. This integration is expected to strengthen the statistical robustness of the study as well as the finding of highly-reliable skin cancer biomarkers. Specifically, the designed operation pipeline has allowed the identification of a small subset of 17 differentially expressed genes (DEGs) from which to distinguish among 7 involved skin states. These genes were obtained from the assessment of a number of potential batch effects on the gene expression data. The biological interpretation of these genes was inspected in the specific literature to understand their underlying information in relation to skin cancer. Finally, in order to assess their possible effectiveness in cancer diagnosis, a cross-validation Support Vector Machines (SVM)-based

  4. Time-sensitive Customer Churn Prediction based on PU Learning

    OpenAIRE

    Wang, Li; Chen, Chaochao; Zhou, Jun; Li, Xiaolong

    2018-01-01

    With the fast development of Internet companies throughout the world, customer churn has become a serious concern. To better help the companies retain their customers, it is important to build a customer churn prediction model to identify the customers who are most likely to churn ahead of time. In this paper, we propose a Time-sensitive Customer Churn Prediction (TCCP) framework based on Positive and Unlabeled (PU) learning technique. Specifically, we obtain the recent data by shortening the...

  5. Design, fabrication and skin-electrode contact analysis of polymer microneedle-based ECG electrodes

    Science.gov (United States)

    O'Mahony, Conor; Grygoryev, Konstantin; Ciarlone, Antonio; Giannoni, Giuseppe; Kenthao, Anan; Galvin, Paul

    2016-08-01

    Microneedle-based ‘dry’ electrodes have immense potential for use in diagnostic procedures such as electrocardiography (ECG) analysis, as they eliminate several of the drawbacks associated with the conventional ‘wet’ electrodes currently used for physiological signal recording. To be commercially successful in such a competitive market, it is essential that dry electrodes are manufacturable in high volumes and at low cost. In addition, the topographical nature of these emerging devices means that electrode performance is likely to be highly dependent on the quality of the skin-electrode contact. This paper presents a low-cost, wafer-level micromoulding technology for the fabrication of polymeric ECG electrodes that use microneedle structures to make a direct electrical contact to the body. The double-sided moulding process can be used to eliminate post-process via creation and wafer dicing steps. In addition, measurement techniques have been developed to characterize the skin-electrode contact force. We perform the first analysis of signal-to-noise ratio dependency on contact force, and show that although microneedle-based electrodes can outperform conventional gel electrodes, the quality of ECG recordings is significantly dependent on temporal and mechanical aspects of the skin-electrode interface.

  6. Design, fabrication and skin-electrode contact analysis of polymer microneedle-based ECG electrodes

    International Nuclear Information System (INIS)

    O’Mahony, Conor; Grygoryev, Konstantin; Ciarlone, Antonio; Giannoni, Giuseppe; Kenthao, Anan; Galvin, Paul

    2016-01-01

    Microneedle-based ‘dry’ electrodes have immense potential for use in diagnostic procedures such as electrocardiography (ECG) analysis, as they eliminate several of the drawbacks associated with the conventional ‘wet’ electrodes currently used for physiological signal recording. To be commercially successful in such a competitive market, it is essential that dry electrodes are manufacturable in high volumes and at low cost. In addition, the topographical nature of these emerging devices means that electrode performance is likely to be highly dependent on the quality of the skin-electrode contact.This paper presents a low-cost, wafer-level micromoulding technology for the fabrication of polymeric ECG electrodes that use microneedle structures to make a direct electrical contact to the body. The double-sided moulding process can be used to eliminate post-process via creation and wafer dicing steps. In addition, measurement techniques have been developed to characterize the skin-electrode contact force. We perform the first analysis of signal-to-noise ratio dependency on contact force, and show that although microneedle-based electrodes can outperform conventional gel electrodes, the quality of ECG recordings is significantly dependent on temporal and mechanical aspects of the skin-electrode interface. (paper)

  7. Skin Stem Cell Hypotheses and Long Term Clone Survival – Explored Using Agent-based Modelling

    Science.gov (United States)

    Li, X.; Upadhyay, A. K.; Bullock, A. J.; Dicolandrea, T.; Xu, J.; Binder, R. L.; Robinson, M. K.; Finlay, D. R.; Mills, K. J.; Bascom, C. C.; Kelling, C. K.; Isfort, R. J.; Haycock, J. W.; MacNeil, S.; Smallwood, R. H.

    2013-01-01

    Epithelial renewal in skin is achieved by the constant turnover and differentiation of keratinocytes. Three popular hypotheses have been proposed to explain basal keratinocyte regeneration and epidermal homeostasis: 1) asymmetric division (stem-transit amplifying cell); 2) populational asymmetry (progenitor cell with stochastic fate); and 3) populational asymmetry with stem cells. In this study, we investigated lineage dynamics using these hypotheses with a 3D agent-based model of the epidermis. The model simulated the growth and maintenance of the epidermis over three years. The offspring of each proliferative cell was traced. While all lineages were preserved in asymmetric division, the vast majority were lost when assuming populational asymmetry. The third hypothesis provided the most reliable mechanism for self-renewal by preserving genetic heterogeneity in quiescent stem cells, and also inherent mechanisms for skin ageing and the accumulation of genetic mutation. PMID:23712735

  8. Skin stem cell hypotheses and long term clone survival--explored using agent-based modelling.

    Science.gov (United States)

    Li, X; Upadhyay, A K; Bullock, A J; Dicolandrea, T; Xu, J; Binder, R L; Robinson, M K; Finlay, D R; Mills, K J; Bascom, C C; Kelling, C K; Isfort, R J; Haycock, J W; MacNeil, S; Smallwood, R H

    2013-01-01

    Epithelial renewal in skin is achieved by the constant turnover and differentiation of keratinocytes. Three popular hypotheses have been proposed to explain basal keratinocyte regeneration and epidermal homeostasis: 1) asymmetric division (stem-transit amplifying cell); 2) populational asymmetry (progenitor cell with stochastic fate); and 3) populational asymmetry with stem cells. In this study, we investigated lineage dynamics using these hypotheses with a 3D agent-based model of the epidermis. The model simulated the growth and maintenance of the epidermis over three years. The offspring of each proliferative cell was traced. While all lineages were preserved in asymmetric division, the vast majority were lost when assuming populational asymmetry. The third hypothesis provided the most reliable mechanism for self-renewal by preserving genetic heterogeneity in quiescent stem cells, and also inherent mechanisms for skin ageing and the accumulation of genetic mutation.

  9. Polymer-based candle-shaped microneedle electrodes for electroencephalography on hairy skin

    Science.gov (United States)

    Arai, Miyako; Kudo, Yuta; Miki, Norihisa

    2016-06-01

    In this paper, we report on the optimization of the shape of dry microneedle electrodes for electroencephalography (EEG) on hairy locations and compare the electrodes we developed with conventional wet electrodes. We propose the use of SU-8-based candle-shaped microneedle electrodes (CMEs), which have pillars of 1.0 mm height and 0.4 mm diameter with a gap of 0.43 mm between pillars. Microneedles are formed on the top of the pillars. The shape was determined by how well the pillars can avoid hairs and support the microneedles to penetrate through the stratum corneum. The skin-electrode contact impedances of the fabricated CMEs were found to be higher and less stable than those of conventional wet electrodes. However, the CMEs successfully acquired signals with qualities as good as those of conventional wet electrodes. Given the usability of the CMEs, which do not require skin preparation or gel, they are promising alternatives to conventional wet electrodes.

  10. Probabilistic hazard assessment for skin sensitization potency by dose–response modeling using feature elimination instead of quantitative structure–activity relationships

    Science.gov (United States)

    McKim, James M.; Hartung, Thomas; Kleensang, Andre; Sá-Rocha, Vanessa

    2016-01-01

    Supervised learning methods promise to improve integrated testing strategies (ITS), but must be adjusted to handle high dimensionality and dose–response data. ITS approaches are currently fueled by the increasing mechanistic understanding of adverse outcome pathways (AOP) and the development of tests reflecting these mechanisms. Simple approaches to combine skin sensitization data sets, such as weight of evidence, fail due to problems in information redundancy and high dimension-ality. The problem is further amplified when potency information (dose/response) of hazards would be estimated. Skin sensitization currently serves as the foster child for AOP and ITS development, as legislative pressures combined with a very good mechanistic understanding of contact dermatitis have led to test development and relatively large high-quality data sets. We curated such a data set and combined a recursive variable selection algorithm to evaluate the information available through in silico, in chemico and in vitro assays. Chemical similarity alone could not cluster chemicals’ potency, and in vitro models consistently ranked high in recursive feature elimination. This allows reducing the number of tests included in an ITS. Next, we analyzed with a hidden Markov model that takes advantage of an intrinsic inter-relationship among the local lymph node assay classes, i.e. the monotonous connection between local lymph node assay and dose. The dose-informed random forest/hidden Markov model was superior to the dose-naive random forest model on all data sets. Although balanced accuracy improvement may seem small, this obscures the actual improvement in misclassifications as the dose-informed hidden Markov model strongly reduced "false-negatives" (i.e. extreme sensitizers as non-sensitizer) on all data sets. PMID:26046447

  11. Beyond the GUM: variance-based sensitivity analysis in metrology

    International Nuclear Information System (INIS)

    Lira, I

    2016-01-01

    Variance-based sensitivity analysis is a well established tool for evaluating the contribution of the uncertainties in the inputs to the uncertainty in the output of a general mathematical model. While the literature on this subject is quite extensive, it has not found widespread use in metrological applications. In this article we present a succinct review of the fundamentals of sensitivity analysis, in a form that should be useful to most people familiarized with the Guide to the Expression of Uncertainty in Measurement (GUM). Through two examples, it is shown that in linear measurement models, no new knowledge is gained by using sensitivity analysis that is not already available after the terms in the so-called ‘law of propagation of uncertainties’ have been computed. However, if the model behaves non-linearly in the neighbourhood of the best estimates of the input quantities—and if these quantities are assumed to be statistically independent—sensitivity analysis is definitely advantageous for gaining insight into how they can be ranked according to their importance in establishing the uncertainty of the measurand. (paper)

  12. Skin sensitisation quantitative risk assessment (QRA) based on aggregate dermal exposure to methylisothiazolinone in personal care and household cleaning products.

    NARCIS (Netherlands)

    Ezendam, J; Bokkers, B G H; Bil, W; Delmaar, J E

    2017-01-01

    Contact allergy to preservatives is an important public health problem. Ideally, new substances should be evaluated for the risk on skin sensitization before market entry, for example by using a quantitative risk assessment (QRA) as developed for fragrances. As a proof-of-concept, this QRA was

  13. GABA and GABA-Alanine from the Red Microalgae Rhodosorus marinus Exhibit a Significant Neuro-Soothing Activity through Inhibition of Neuro-Inflammation Mediators and Positive Regulation of TRPV1-Related Skin Sensitization

    Science.gov (United States)

    Scandolera, Amandine; Hubert, Jane; Humeau, Anne; Lambert, Carole; De Bizemont, Audrey; Winkel, Chris; Kaouas, Abdelmajid; Renault, Jean-Hugues; Reynaud, Romain

    2018-01-01

    The aim of the present study was to investigate the neuro-soothing activity of a water-soluble hydrolysate obtained from the red microalgae Rhodosorus marinus Geitler (Stylonemataceae). Transcriptomic analysis performed on ≈100 genes related to skin biological functions firstly revealed that the crude Rhodosorus marinus extract was able to significantly negatively modulate specific genes involved in pro-inflammation (interleukin 1α encoding gene, IL1A) and pain detection related to tissue inflammation (nerve growth factor NGF and its receptor NGFR). An in vitro model of normal human keratinocytes was then used to evaluate the ability of the Rhodosorus marinus extract to control the release of neuro-inflammation mediators under phorbol myristate acetate (PMA)-induced inflammatory conditions. The extract incorporated at 1% and 3% significantly inhibited the release of IL-1α and NGF secretion. These results were confirmed in a co-culture system of reconstructed human epithelium and normal human epidermal keratinocytes on which a cream formulated with the Rhodosorus marinus extract at 1% and 3% was topically applied after systemic induction of neuro-inflammation. Finally, an in vitro model of normal human astrocytes was developed for the evaluation of transient receptor potential vanilloid 1 (TRPV1) receptor modulation, mimicking pain sensing related to neuro-inflammation as observed in sensitive skins. Treatment with the Rhodosorus marinus extract at 1% and 3% significantly decreased PMA-mediated TRPV1 over-expression. In parallel with these biological experiments, the crude Rhodosorus marinus extract was fractionated by centrifugal partition chromatography (CPC) and chemically profiled by a recently developed 13C NMR-based dereplication method. The CPC-generated fractions as well as pure metabolites were tested again in vitro in an attempt to identify the biologically active constituents involved in the neuro-soothing activity of the Rhodosorus marinus extract

  14. GABA and GABA-Alanine from the Red Microalgae Rhodosorus marinus Exhibit a Significant Neuro-Soothing Activity through Inhibition of Neuro-Inflammation Mediators and Positive Regulation of TRPV1-Related Skin Sensitization

    Directory of Open Access Journals (Sweden)

    Amandine Scandolera

    2018-03-01

    Full Text Available The aim of the present study was to investigate the neuro-soothing activity of a water-soluble hydrolysate obtained from the red microalgae Rhodosorus marinus Geitler (Stylonemataceae. Transcriptomic analysis performed on ≈100 genes related to skin biological functions firstly revealed that the crude Rhodosorus marinus extract was able to significantly negatively modulate specific genes involved in pro-inflammation (interleukin 1α encoding gene, IL1A and pain detection related to tissue inflammation (nerve growth factor NGF and its receptor NGFR. An in vitro model of normal human keratinocytes was then used to evaluate the ability of the Rhodosorus marinus extract to control the release of neuro-inflammation mediators under phorbol myristate acetate (PMA-induced inflammatory conditions. The extract incorporated at 1% and 3% significantly inhibited the release of IL-1α and NGF secretion. These results were confirmed in a co-culture system of reconstructed human epithelium and normal human epidermal keratinocytes on which a cream formulated with the Rhodosorus marinus extract at 1% and 3% was topically applied after systemic induction of neuro-inflammation. Finally, an in vitro model of normal human astrocytes was developed for the evaluation of transient receptor potential vanilloid 1 (TRPV1 receptor modulation, mimicking pain sensing related to neuro-inflammation as observed in sensitive skins. Treatment with the Rhodosorus marinus extract at 1% and 3% significantly decreased PMA-mediated TRPV1 over-expression. In parallel with these biological experiments, the crude Rhodosorus marinus extract was fractionated by centrifugal partition chromatography (CPC and chemically profiled by a recently developed 13C NMR-based dereplication method. The CPC-generated fractions as well as pure metabolites were tested again in vitro in an attempt to identify the biologically active constituents involved in the neuro-soothing activity of the Rhodosorus

  15. Texture-based characterization of subskin features by specified laser speckle effects at λ = 650 nm region for more accurate parametric 'skin age' modelling.

    Science.gov (United States)

    Orun, A B; Seker, H; Uslan, V; Goodyer, E; Smith, G

    2017-06-01

    The textural structure of 'skin age'-related subskin components enables us to identify and analyse their unique characteristics, thus making substantial progress towards establishing an accurate skin age model. This is achieved by a two-stage process. First by the application of textural analysis using laser speckle imaging, which is sensitive to textural effects within the λ = 650 nm spectral band region. In the second stage, a Bayesian inference method is used to select attributes from which a predictive model is built. This technique enables us to contrast different skin age models, such as the laser speckle effect against the more widely used normal light (LED) imaging method, whereby it is shown that our laser speckle-based technique yields better results. The method introduced here is non-invasive, low cost and capable of operating in real time; having the potential to compete against high-cost instrumentation such as confocal microscopy or similar imaging devices used for skin age identification purposes. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  16. CLASSIFICATION OF SEVERAL SKIN CANCER TYPES BASED ON AUTOFLUORESCENCE INTENSITY OF VISIBLE LIGHT TO NEAR INFRARED RATIO

    Directory of Open Access Journals (Sweden)

    Aryo Tedjo

    2009-12-01

    Full Text Available Skin cancer is a malignant growth on the skin caused by many factors. The most common skin cancers are Basal Cell Cancer (BCC and Squamous Cell Cancer (SCC. This research uses a discriminant analysis to classify some tissues of skin cancer based on criterion number of independent variables. An independent variable is variation of excitation light sources (LED lamp, filters, and sensors to measure Autofluorescence Intensity (IAF of visible light to near infrared (VIS/NIR ratio of paraffin embedded tissue biopsy from BCC, SCC, and Lipoma. From the result of discriminant analysis, it is known that the discriminant function is determined by 4 (four independent variables i.e., Blue LED-Red Filter, Blue LED-Yellow Filter, UV LED-Blue Filter, and UV LED-Yellow Filter. The accuracy of discriminant in classifying the analysis of three skin cancer tissues is 100 %.

  17. Evaluation of the skin sensitization potential of chemicals using expression of co-stimulatory molecules, CD54 and CD86, on the naive THP-1 cell line.

    Science.gov (United States)

    Yoshida, Y; Sakaguchi, H; Ito, Y; Okuda, M; Suzuki, H

    2003-04-01

    It has been known that dendritic cells (DCs) including Langerhans cells (LCs) play a critical role in the skin sensitization process. Many attempts have been made to develop in vitro sensitization tests that employ DCs derived from peripheral blood mononuclear cells (PBMC-DC) or CD34+ hematopoietic progenitor cells (CD34+ HPC) purified from cord blood or bone marrow. However, the use of the DCs in in vitro methods has been difficult due to the nature of these cells such as low levels in the source and/or donor-to-donor variability. In our studies, we employed the human monocytic leukemia cell line, THP-1, in order to avoid some of these difficulties. At the start, we examined whether treatment of the cells with various cytokines could produce DCs from THP-1. Treatment of THP-1 cells with cytokines such as GM-CSF, IL-4, TNF-alpha, and/or PMA did induce some phenotypic changes in THP-1 cells that were characteristic of DCs. Subsequently, responses to a known sensitizer, dinitrochlorobenzene (DNCB), and a non-sensitizer, dimethyl sulfoxide (DMSO) or sodium lauryl sulfate (SLS), on the expression of co-stimulatory molecules, CD54 and CD86, were examined between the naive cells and the cytokine-treated cells. Interestingly, the naive THP-1 cells responded only to DNCB and the response to the sensitizer was more distinct than cytokine-treated THP-1 cells. Similar phenomena were also observed in the human myeloid leukemia cell line, KG-1. Furthermore, with treatment of DNCB, naive THP-1 cells showed augmented expression of HLA, CD80 and secretion of IL-1 beta. The response of THP-1 cells to a sensitizer was similar to that of LCs/DCs. Upon demonstrating the differentiation of monocyte cells in our system, we then evaluated a series of chemicals, including known sensitizers and non-sensitizers, for their potential to augment CD54 and CD86 expression on naive THP-1 cells. Indeed, known sensitizers such as PPD and 2-MBT significantly augmented CD54 and CD86 expression in a

  18. Optical Fiber Sensors Based on Polymeric Sensitive Coatings

    Directory of Open Access Journals (Sweden)

    Pedro J. Rivero

    2018-03-01

    Full Text Available Polymer technology is one of the fastest growing fields of contemporary research due to the possibility of using a wide variety of synthetic chemical routes for obtaining a polymeric network with a well-defined structure, resulting in materials with outstanding macroscopic properties. Surface engineering techniques based on the implementation of polymeric structures can be used as an interesting tool for the design of materials with functional properties. In this sense, the use of fabrication techniques for the design of nanostructured polymeric coatings is showing an important growth due to the intrinsic advantages of controlling the structure at a nanoscale level because physical, chemical, or optical properties can be considerably improved in comparison with the bulk materials. In addition, the presence of these sensitive polymeric coatings on optical fiber is a hot topic in the scientific community for its implementation in different market niches because a wide variety of parameters can be perfectly measured with a high selectivity, sensitivity, and fast response time. In this work, the two main roles that a polymeric sensitive matrix can play on an optical fiber for sensing applications are evaluated. In a first section, the polymers are used as a solid support for the immobilization of specific sensitive element, whereas in the second section the polymeric matrix is used as the chemical transducer itself. Additionally, potential applications of the optical fiber sensors in fields as diverse as biology, chemistry, engineering, environmental, industry or medicine will be presented in concordance with these two main roles of the polymeric sensitive matrices.

  19. Skin Diseases: Skin Health and Skin Diseases

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Skin Health and Skin Diseases Past Issues / Fall 2008 Table of Contents ... acne to wrinkles Did you know that your skin is the largest organ of your body? It ...

  20. Evaluation of bacterial nanocellulose-based uniform wound dressing for large area skin transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Lina [Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); National Engineering Research Center for Nano-Medicine, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhou, Ping [Institute of Organ Transplant of Tongji Hospital, Huazhong University of Science and Technology, Wuhan (China); Zhang, Shengmin [Advanced Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan (China); Yang, Guang, E-mail: yang_sunny@yahoo.com [Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); National Engineering Research Center for Nano-Medicine, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2013-07-01

    Bacterial nanocellulose (BNC) was biosynthesized by Gluconacetobacter xylinus. The surface area, physicochemical structure and morphology of the materials were characterized. Here provides a method for an efficient production of uniform BNC, which is beneficial for the fast characterization and evaluation of BNC. In vitro cytotoxicity of the materials was evaluated by the proliferation, the adhesion, the viability and the morphology of NIH/3T3 cells. Low cytotoxicity of the BNC was observed, and micrographs demonstrate a good proliferation and adhesion of NIH/3T3 cells on BNC. Large area full-thickness skin defects were made on the back of C57BL/6 mice in animal surgery. The wounds were transplanted with BNC films and the results compared to those in a control group. The rehabilitation of the wound surfaces and the pathological sections of mice were investigated and are discussed. Histological examinations demonstrated faster and better healing effect and lower inflammatory response in the BNC group than those in the control group. Preliminary results on wound dressings from BNC show a curative effect promoting the healing of epithelial tissue. BNC is a promising natural polymer with medical applications in wound dressings. - Highlights: • BNC is expected to be a promising material in wound healing and skin transplantation. • We studied surface area, physicochemical structures and morphology of uniform BNC. • Cyto-evaluation results of BNC-based wound dressing show a good biocompatibility. • Large area skin transplantation experiments suggest a good performance of healing.

  1. Evaluation of bacterial nanocellulose-based uniform wound dressing for large area skin transplantation

    International Nuclear Information System (INIS)

    Fu, Lina; Zhou, Ping; Zhang, Shengmin; Yang, Guang

    2013-01-01

    Bacterial nanocellulose (BNC) was biosynthesized by Gluconacetobacter xylinus. The surface area, physicochemical structure and morphology of the materials were characterized. Here provides a method for an efficient production of uniform BNC, which is beneficial for the fast characterization and evaluation of BNC. In vitro cytotoxicity of the materials was evaluated by the proliferation, the adhesion, the viability and the morphology of NIH/3T3 cells. Low cytotoxicity of the BNC was observed, and micrographs demonstrate a good proliferation and adhesion of NIH/3T3 cells on BNC. Large area full-thickness skin defects were made on the back of C57BL/6 mice in animal surgery. The wounds were transplanted with BNC films and the results compared to those in a control group. The rehabilitation of the wound surfaces and the pathological sections of mice were investigated and are discussed. Histological examinations demonstrated faster and better healing effect and lower inflammatory response in the BNC group than those in the control group. Preliminary results on wound dressings from BNC show a curative effect promoting the healing of epithelial tissue. BNC is a promising natural polymer with medical applications in wound dressings. - Highlights: • BNC is expected to be a promising material in wound healing and skin transplantation. • We studied surface area, physicochemical structures and morphology of uniform BNC. • Cyto-evaluation results of BNC-based wound dressing show a good biocompatibility. • Large area skin transplantation experiments suggest a good performance of healing

  2. Dye-sensitized solar cells based on nanostructured zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Conradt, Jonas; Maier-Flaig, Florian; Sartor, Janos; Fallert, Johannes [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Szmytkowski, Jedrzej; Kalt, Heinz [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Reinhard, Manuel; Colsmann, Alexander [Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Lemmer, Uli [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Lichttechnisches Institut, Karlsruhe (Germany); Balaban, Teodor Silviu [Center for Functional Nanostructures (CFN), Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology, Karlsruhe (Germany)

    2009-07-01

    Hybrid solar cells represent a promising (cost-efficient) alternative to pure inorganic solar cells. We present dye-sensitized solar cells (DSSC) which are based on a zinc oxide (ZnO) electrode covered with a ruthenium dye. Our work focuses on the morphology of the ZnO electrode and its impact on the photovoltaic performance of the solar cell. Nanocrystalline ZnO powder layers and arrays of nanorods are incorporated into the DSSCs. The ZnO nanorods are grown by vapor transport deposition. The morphology and doping concentration of the rods can be controlled by the choice of substrate material, growth condition and catalytic metal layers. The nanorod arrays are expected to fasten the electron transport towards the anode and thereby improve the solar cell efficiency. In addition, novel self-assembling (porphyrin) dyes are tested as sensitizer within a DSSC.

  3. CCD-Based Skinning Injury Recognition on Potato Tubers (Solanum tuberosum L.): A Comparison between Visible and Biospeckle Imaging.

    Science.gov (United States)

    Gao, Yingwang; Geng, Jinfeng; Rao, Xiuqin; Ying, Yibin

    2016-10-18

    Skinning injury on potato tubers is a kind of superficial wound that is generally inflicted by mechanical forces during harvest and postharvest handling operations. Though skinning injury is pervasive and obstructive, its detection is very limited. This study attempted to identify injured skin using two CCD (Charge Coupled Device) sensor-based machine vision technologies, i.e., visible imaging and biospeckle imaging. The identification of skinning injury was realized via exploiting features extracted from varied ROIs (Region of Interests). The features extracted from visible images were pixel-wise color and texture features, while region-wise BA (Biospeckle Activity) was calculated from biospeckle imaging. In addition, the calculation of BA using varied numbers of speckle patterns were compared. Finally, extracted features were implemented into classifiers of LS-SVM (Least Square Support Vector Machine) and BLR (Binary Logistic Regression), respectively. Results showed that color features performed better than texture features in classifying sound skin and injured skin, especially for injured skin stored no less than 1 day, with the average classification accuracy of 90%. Image capturing and processing efficiency can be speeded up in biospeckle imaging, with captured 512 frames reduced to 125 frames. Classification results obtained based on the feature of BA were acceptable for early skinning injury stored within 1 day, with the accuracy of 88.10%. It is concluded that skinning injury can be recognized by visible and biospeckle imaging during different stages. Visible imaging has the aptitude in recognizing stale skinning injury, while fresh injury can be discriminated by biospeckle imaging.

  4. Reliability Coupled Sensitivity Based Design Approach for Gravity Retaining Walls

    Science.gov (United States)

    Guha Ray, A.; Baidya, D. K.

    2012-09-01

    Sensitivity analysis involving different random variables and different potential failure modes of a gravity retaining wall focuses on the fact that high sensitivity of a particular variable on a particular mode of failure does not necessarily imply a remarkable contribution to the overall failure probability. The present paper aims at identifying a probabilistic risk factor ( R f ) for each random variable based on the combined effects of failure probability ( P f ) of each mode of failure of a gravity retaining wall and sensitivity of each of the random variables on these failure modes. P f is calculated by Monte Carlo simulation and sensitivity analysis of each random variable is carried out by F-test analysis. The structure, redesigned by modifying the original random variables with the risk factors, is safe against all the variations of random variables. It is observed that R f for friction angle of backfill soil ( φ 1 ) increases and cohesion of foundation soil ( c 2 ) decreases with an increase of variation of φ 1 , while R f for unit weights ( γ 1 and γ 2 ) for both soil and friction angle of foundation soil ( φ 2 ) remains almost constant for variation of soil properties. The results compared well with some of the existing deterministic and probabilistic methods and found to be cost-effective. It is seen that if variation of φ 1 remains within 5 %, significant reduction in cross-sectional area can be achieved. But if the variation is more than 7-8 %, the structure needs to be modified. Finally design guidelines for different wall dimensions, based on the present approach, are proposed.

  5. Influential Factors of Mother-Infant Skin-to-Skin Contact Based on the Precede-Proceed Model from the Perspective of Midwives in Torbat Heydariyeh Hospitals

    Directory of Open Access Journals (Sweden)

    Mohadeseh Adeli

    2016-07-01

    Full Text Available Background & aim: Skin-to-skin contact immediately after birth plays a pivotal role in proper breastfeeding and mother-infant interaction. Despite numerous benefits of mother-infant skin-to-skin contact, this health behavior is not performed by many midwives. This study aimed to evaluate the influential factors for mother-infant skin-to-skin contact based on the Precede-Proceed model from the perspective of midwives in Torbat Heydariyeh hospitals. Methods:This cross-sectional study was conducted on 50 midwives working in hospitals of Torbat Heydariyeh, Iran in 2015. Demographic data of all participants were collected, and Mother-Newborn Skin-to-Skin Contact Questionnaire was also used based on the Precede-Proceed model. Data analysis was performed in SPSS V.16 using descriptive statistics, tables and graphs. Results: In this study, 88.1% of the midwives had positive attitudes towards skin-to-skin contact, and 90.5% had high perceived self-efficacy in performing the procedure. Major obstacles against establishing proper skin-to-skin contact were neonatal diseases and maternal fatigue (83.3% from the perspective of midwives. Moreover, 87.5% and 90.5% of the midwives emphasized the pivotal role of social support and motivation, respectively in implementing skin-to-skin contact. Also, more than 90% of the midwives considered training programs, service access and adequate facilities to be influential in the proper establishment of skin-to-skin contact. Conclusion: According to the results of this study, the majority of midwives believed that enabling and reinforcing factors had significant effects on the proper establishment of mother-infant skin-to-skin contact. Therefore, it is recommended thateducational interventions be planned for parents, their family members and health care personnel involved in processes of childbirth and infant care. Furthermore, organizational planning and executive procedures should be developed to study the

  6. In vivo wide-field multispectral dosimeter for use in ALA-PpIX based photodynamic therapy of skin

    Science.gov (United States)

    LaRochelle, Ethan P. M.; Davis, Scott C.; de Souza, Ana Luiza Ribeiro; Pogue, Brian W.

    2017-02-01

    Photodynamic therapy (PDT) for Actinic Kertoses (AK) using aminoluvelinic acid (ALA) is an FDA-approved treatment, which is generally effective, yet response rates vary. The origin of the variability is not well characterized, but may be related to inter-patient variability in the production of protoporphyrin IX (PpIX). While fiber-based point probe systems provide a method for measuring PpIX production, these measurements have demonstrated large spatial and inter-operator variability. Thus, in an effort to improve patient-specific dosimetry and treatment it is important to develop a robust system that accounts for spatial variability and reduces the chance of operator errors. To address this need, a wide-field multispectral imaging system was developed that is capable of quantifying maps of PpIX in both liquid phantoms and in vivo experiments, focusing on high sensitivity light signals. The system uses both red and blue excitation to elicit a fluorescent response at varying skin depths. A ten-position filter wheel with bandpass filters ranging from 635nm to 710nm are used to capture images along the emission band. A linear least-square spectral fitting algorithm provides the ability to decouple background autofluorescence from PpIX fluorescence, which has improved the system sensitivity by an order of magnitude, detecting nanomolar PpIX concentrations in liquid phantoms in the presence of 2% whole blood and 2% intralipid.

  7. Skin protective behavior amongst girl students; based on health belief model.

    Directory of Open Access Journals (Sweden)

    Ali Davati

    2013-09-01

    Full Text Available Skin cancer is the most prevalent type of cancer in most of the countries and more than 90% of cancer cases are related to ultra violet rays of the sun. Therefore protective behaviors against sunlight are considered the most essential measures for skin cancer prevention. This study has been conducted to determine the frequency of protective behavior against sunlight among female students of Tehran city high schools. The Health Belief Model has been used for this cross-sectional study to analyze the factors related to protective behaviors. A multi-phase sampling method was used. 941 female student of Tehran city high schools were studied using a probed question form. The data were then analyzed using SPSS software. During the study of protective behaviors against the sunlight, 24.7% of participants mentioned that they always use sunscreen. The behavior of using sunscreen is related to perceived sensitivity, severity and benefit amongst the students (P<0.05. Also 3.8% of the students who participated in our study were always using gloves in summer to protect against sunlight. The behavior of using gloves in summer was also related to perceived sensitivity, severity and benefit (P<0.05. Physicians were the most effective influencing people with 84.9% influence on the appropriate decision making by these students. There is a low frequency of protective behavior against sunlight among the female students of Tehran city high schools. These findings show the necessity of training the students in this regard and promote the protective behaviors amongst them.

  8. Full-field ultrasonic inspection for a composite sandwich plate skin-core debonding detection using laser-based ultrasonics

    Science.gov (United States)

    Chong, See Yenn; Victor, Jared J.; Todd, Michael D.

    2017-04-01

    In this paper, a full-field ultrasonic guided wave method is proposed to inspect a composite sandwich specimen made for an aircraft engine nacelle. The back skin/core interface of the specimen is built with two fabricated disbond defects (diameters of 12.7 mm and 25.4 mm) by removing areas of the adhesive used to bond the back skin to the core. A laser ultrasonic interrogation system (LUIS) incorporated with a disbond detection algorithm is developed. The system consists of a 1-kHz laser ultrasonic scanning system and a single fixed ultrasonic sensor to interrogate ultrasonic guided waves in the sandwich specimen. The interest area of 400 mm × 400 mm is scanned at a 0.5 mm scan interval. The corresponding full-field ultrasonic data is obtained and generated in the three-dimensional (3-D) space-time domain. Then, the 3-D full-field ultrasonic data is Fourier transformed and the ultrasonic frequency spectra are analyzed to determine the dominant frequency that is sensitive to the disbond defects. Continuous wavelet transform (CWT) based on fast Fourier transform (FFT) is implemented as a single-frequency bandpass filter to filter the full-field ultrasonic data in the 3-D space-time domain at the selected dominant frequency. The LUIS has shown the ability to detect the disbond with diameters of 11 mm and 23 mm which match to the pre-determined disbond sizes well. For future research, a robust signal processing algorithm and a model-based matched filter will be investigated to make the detection process autonomous and improve detectability

  9. Application of BALB/c mouse in the local lymph node assay:BrdU-ELISA for the prediction of the skin sensitizing potential of chemicals.

    Science.gov (United States)

    Hou, Fenxia; Xing, Caihong; Li, Bin; Cheng, Juan; Chen, Wei; Zhang, Man

    2015-01-01

    Allergic contact dermatitis (ACD) is a skin disease characterized by eczema and itching. A considerable proportion of chemicals induce ACD in humans. More than 10,000 substances should be tested for skin sensitization potential under the Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) regulation. The Local Lymph Node Assay (LLNA) has been designated as the first-choice in vivo assay for sensitization testing by REACH. The LLNA:BrdU-ELISA is a validated non-radioactive modification to the LLNA. For both the LLNA and the LLNA:BrdU-ELISA, CBA/JN mouse is the preferred mouse strain recommended in the regulatory guidelines. However, the availability of CBA/JN mouse in China is only limited to a few animal suppliers, which makes the mouse difficult to obtain. BALB/c mouse, which is widely commercially available, is considered for alternative use but it can only be used in the assay after it has been evaluated by formal validation study. Thus, a validation study was conducted in our laboratory to determine if BALB/c mouse could also be used in the LLNA:BrdU-ELISA. Forty-three test substances including 32 LLNA sensitizers and 11 LLNA non-sensitizers, their vehicles and each concentration used were the same as that used in the formal validation study for the LLNA:BrdU-ELISA using CBA/JN mouse. Female BALB/c mice of 8-10 weeks old were randomly allocated to groups (four mice per group). The test substance (25 μl) or the vehicle alone was applied to the dorsum of both ears daily for 3 consecutive days. A single intraperitoneal injection of 0.5 ml of BrdU (10mg/ml) solution was given on day 5. On day 6, a pair of auricular lymph nodes from each mouse was excised, weighed and stored at -20°C until BrdU-ELISA was conducted. This validation study for the LLNA:BrdU-ELISA using BALB/c mouse correctly identified 30 of 31 sensitizers and 8 of 11 non-sensitizers. The accuracy, sensitivity, specificity, false positive rate, false negative rate

  10. Parameter uncertainty effects on variance-based sensitivity analysis

    International Nuclear Information System (INIS)

    Yu, W.; Harris, T.J.

    2009-01-01

    In the past several years there has been considerable commercial and academic interest in methods for variance-based sensitivity analysis. The industrial focus is motivated by the importance of attributing variance contributions to input factors. A more complete understanding of these relationships enables companies to achieve goals related to quality, safety and asset utilization. In a number of applications, it is possible to distinguish between two types of input variables-regressive variables and model parameters. Regressive variables are those that can be influenced by process design or by a control strategy. With model parameters, there are typically no opportunities to directly influence their variability. In this paper, we propose a new method to perform sensitivity analysis through a partitioning of the input variables into these two groupings: regressive variables and model parameters. A sequential analysis is proposed, where first an sensitivity analysis is performed with respect to the regressive variables. In the second step, the uncertainty effects arising from the model parameters are included. This strategy can be quite useful in understanding process variability and in developing strategies to reduce overall variability. When this method is used for nonlinear models which are linear in the parameters, analytical solutions can be utilized. In the more general case of models that are nonlinear in both the regressive variables and the parameters, either first order approximations can be used, or numerically intensive methods must be used

  11. Variance-based sensitivity analysis for wastewater treatment plant modelling.

    Science.gov (United States)

    Cosenza, Alida; Mannina, Giorgio; Vanrolleghem, Peter A; Neumann, Marc B

    2014-02-01

    Global sensitivity analysis (GSA) is a valuable tool to support the use of mathematical models that characterise technical or natural systems. In the field of wastewater modelling, most of the recent applications of GSA use either regression-based methods, which require close to linear relationships between the model outputs and model factors, or screening methods, which only yield qualitative results. However, due to the characteristics of membrane bioreactors (MBR) (non-linear kinetics, complexity, etc.) there is an interest to adequately quantify the effects of non-linearity and interactions. This can be achieved with variance-based sensitivity analysis methods. In this paper, the Extended Fourier Amplitude Sensitivity Testing (Extended-FAST) method is applied to an integrated activated sludge model (ASM2d) for an MBR system including microbial product formation and physical separation processes. Twenty-one model outputs located throughout the different sections of the bioreactor and 79 model factors are considered. Significant interactions among the model factors are found. Contrary to previous GSA studies for ASM models, we find the relationship between variables and factors to be non-linear and non-additive. By analysing the pattern of the variance decomposition along the plant, the model factors having the highest variance contributions were identified. This study demonstrates the usefulness of variance-based methods in membrane bioreactor modelling where, due to the presence of membranes and different operating conditions than those typically found in conventional activated sludge systems, several highly non-linear effects are present. Further, the obtained results highlight the relevant role played by the modelling approach for MBR taking into account simultaneously biological and physical processes. © 2013.

  12. Sun Exposure Prevalence and Associated Skin Health Habits: Results from the Austrian Population-Based UVSkinRisk Survey

    Directory of Open Access Journals (Sweden)

    Daniela Haluza

    2016-01-01

    Full Text Available Recreational sun exposure accounts for a large number of acute and chronic dermatological diseases, including skin cancer. This study aimed at estimating the one-year prevalence of sun exposure and skin health-associated knowledge and attitudes among Austrian citizens. The population-based UVSkinRisk survey investigated a representative sample of Austrian adults using a structured questionnaire. In total, 1500 study subjects (median age 33.0 years, 50.5% females participated in this questionnaire survey. Among study participants, prevalence of sun exposure was 47%, with slightly higher rates in males (48% compared to females (46%. Younger age, lower professional category, darker skin type, motives to tan, sunbed use, sunburn, and outdoor sport activity increased the odds for prevalent sun exposure. This is the first population-based study evaluating the prevailing sun exposure and recreational habits influencing skin health among Austrian citizens. Despite public media campaigns educating on the harmful effects of sunlight exposure, we found a high prevalence of self-reported sunlight exposure. The results suggest that multifaceted socio-cultural characteristics stimulate recreational sun exposure and tanning habits. Communicating individualized Public (Skin Health messages might be the key to prevent photo-induced skin health hazards in light-skinned populations. The practical and theoretical implications of these findings are discussed.

  13. Thermodynamics-based Metabolite Sensitivity Analysis in metabolic networks.

    Science.gov (United States)

    Kiparissides, A; Hatzimanikatis, V

    2017-01-01

    The increasing availability of large metabolomics datasets enhances the need for computational methodologies that can organize the data in a way that can lead to the inference of meaningful relationships. Knowledge of the metabolic state of a cell and how it responds to various stimuli and extracellular conditions can offer significant insight in the regulatory functions and how to manipulate them. Constraint based methods, such as Flux Balance Analysis (FBA) and Thermodynamics-based flux analysis (TFA), are commonly used to estimate the flow of metabolites through genome-wide metabolic networks, making it possible to identify the ranges of flux values that are consistent with the studied physiological and thermodynamic conditions. However, unless key intracellular fluxes and metabolite concentrations are known, constraint-based models lead to underdetermined problem formulations. This lack of information propagates as uncertainty in the estimation of fluxes and basic reaction properties such as the determination of reaction directionalities. Therefore, knowledge of which metabolites, if measured, would contribute the most to reducing this uncertainty can significantly improve our ability to define the internal state of the cell. In the present work we combine constraint based modeling, Design of Experiments (DoE) and Global Sensitivity Analysis (GSA) into the Thermodynamics-based Metabolite Sensitivity Analysis (TMSA) method. TMSA ranks metabolites comprising a metabolic network based on their ability to constrain the gamut of possible solutions to a limited, thermodynamically consistent set of internal states. TMSA is modular and can be applied to a single reaction, a metabolic pathway or an entire metabolic network. This is, to our knowledge, the first attempt to use metabolic modeling in order to provide a significance ranking of metabolites to guide experimental measurements. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier

  14. Pigmented skin lesion detection using random forest and wavelet-based texture

    Science.gov (United States)

    Hu, Ping; Yang, Tie-jun

    2016-10-01

    The incidence of cutaneous malignant melanoma, a disease of worldwide distribution and is the deadliest form of skin cancer, has been rapidly increasing over the last few decades. Because advanced cutaneous melanoma is still incurable, early detection is an important step toward a reduction in mortality. Dermoscopy photographs are commonly used in melanoma diagnosis and can capture detailed features of a lesion. A great variability exists in the visual appearance of pigmented skin lesions. Therefore, in order to minimize the diagnostic errors that result from the difficulty and subjectivity of visual interpretation, an automatic detection approach is required. The objectives of this paper were to propose a hybrid method using random forest and Gabor wavelet transformation to accurately differentiate which part belong to lesion area and the other is not in a dermoscopy photographs and analyze segmentation accuracy. A random forest classifier consisting of a set of decision trees was used for classification. Gabor wavelets transformation are the mathematical model of visual cortical cells of mammalian brain and an image can be decomposed into multiple scales and multiple orientations by using it. The Gabor function has been recognized as a very useful tool in texture analysis, due to its optimal localization properties in both spatial and frequency domain. Texture features based on Gabor wavelets transformation are found by the Gabor filtered image. Experiment results indicate the following: (1) the proposed algorithm based on random forest outperformed the-state-of-the-art in pigmented skin lesions detection (2) and the inclusion of Gabor wavelet transformation based texture features improved segmentation accuracy significantly.

  15. Quantitatively characterizing microstructural variations of skin tissues during ultraviolet radiation damaging process based on Mueller matrix polarimetry

    Science.gov (United States)

    Sheng, Wei; He, Honghui; Dong, Yang; Ma, Hui

    2018-02-01

    As one of the most fundamental features of light, polarization can be used to develop imaging techniques which can provide insight into the optical and structural properties of tissues. Especially, the Mueller matrix polarimetry is suitable to detect the changes in collagen and elastic fibres, which are the main compositions of skin tissue. Here we demonstrate a novel quantitative, non-contact and in situ technique to monitor the microstructural variations of skin tissue during ultraviolet radiation (UVR) induced photoaging based on Mueller matrix polarimetry. Specifically, we measure the twodimensional (2D) backscattering Mueller matrices of nude mouse skin samples, then calculate and analyze the Mueller matrix derived parameters during the skin photoaging and self-repairing processes. To induce three-day skin photoaging, the back skin of each mouse is irradiated with UVR (0.05J/cm2) for five minutes per day. After UVR, the microstructures of the nude mouse skin are damaged. During the process of UV damage, we measure the backscattering Mueller matrices of the mouse skin samples and examine the relationship between the Mueller matrix parameters and the microstructural variations of skin tissue quantitatively. The comparisons between the UVR damaged groups with and without sunscreens show that the Mueller matrix derived parameters are potential indicators for fibrous microstructure variation in skin tissue. The pathological examinations and Monte Carlo simulations confirm the relationship between the values of Mueller matrix parameters and the changes of fibrous structures. Combined with smart phones or wearable devices, this technique may have a good application prospect in the fields of cosmetics and dermatological health.

  16. Improved Extreme Learning Machine based on the Sensitivity Analysis

    Science.gov (United States)

    Cui, Licheng; Zhai, Huawei; Wang, Benchao; Qu, Zengtang

    2018-03-01

    Extreme learning machine and its improved ones is weak in some points, such as computing complex, learning error and so on. After deeply analyzing, referencing the importance of hidden nodes in SVM, an novel analyzing method of the sensitivity is proposed which meets people’s cognitive habits. Based on these, an improved ELM is proposed, it could remove hidden nodes before meeting the learning error, and it can efficiently manage the number of hidden nodes, so as to improve the its performance. After comparing tests, it is better in learning time, accuracy and so on.

  17. Highly Sensitive Flexible Magnetic Sensor Based on Anisotropic Magnetoresistance Effect.

    Science.gov (United States)

    Wang, Zhiguang; Wang, Xinjun; Li, Menghui; Gao, Yuan; Hu, Zhongqiang; Nan, Tianxiang; Liang, Xianfeng; Chen, Huaihao; Yang, Jia; Cash, Syd; Sun, Nian-Xiang

    2016-11-01

    A highly sensitive flexible magnetic sensor based on the anisotropic magnetoresistance effect is fabricated. A limit of detection of 150 nT is observed and excellent deformation stability is achieved after wrapping of the flexible sensor, with bending radii down to 5 mm. The flexible AMR sensor is used to read a magnetic pattern with a thickness of 10 μm that is formed by ferrite magnetic inks. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Sun Protection and Skin Examination Practices in a Setting of High Ambient Solar Radiation: A Population-Based Cohort Study.

    Science.gov (United States)

    Olsen, Catherine M; Thompson, Bridie S; Green, Adèle C; Neale, Rachel E; Whiteman, David C

    2015-09-01

    Primary prevention and early detection are integral strategies to reduce the burden of skin cancer. To describe the prevalence of sun protection and skin examination practices in a population exposed to high levels of ambient solar radiation and to identify associated factors. Cross-sectional analyses of baseline data from a prospective cohort of 40,172 adults aged 40 through 69 years from Queensland, Australia, recruited in 2011. We obtained data on all melanoma diagnoses through 2009 via record linkage with the Queensland Cancer Registry (notifications have been mandatory since 1982). We calculated prevalence proportion ratios to compare prevalence of sun protection and skin examination practices in 3 separate groups: those with a history of melanoma (group 1), those with a self-reported history of treated actinic lesions (group 2), and those without either (group 3). We used multivariate generalized linear models to identify factors associated with each practice. Participants with a previously confirmed melanoma (group 1; n = 1433) and/or treated actinic lesions (group 2; n = 24,006) were more likely than those without (group 3; n = 14,733) to report sun protection practices, including regular use of sunscreen (53.3%, 45.1%, and 38.1%, respectively) and wearing hats (74.7%, 68.2%, and 58.2%, respectively). They were also more likely to have had a whole-body skin examination by a physician in the past 3 years (93.7%, 83.4%, and 52.1%, respectively). Within all 3 groups, the strongest association with sun protection practices was with sun-sensitive skin type. Within group 3 (no history of treated skin lesions), the strongest factor associated with clinical skin examinations was self-reported nevus density at 21 years of age, whereas a family history of melanoma was a significant factor in groups 2 and 3. In this large sample exposed to high levels of ambient solar radiation, sun protection and skin examination practices were most frequent among those

  19. Immediate and long-term effects of polysaccharides-based formulations on human skin

    Directory of Open Access Journals (Sweden)

    Flavio Bueno de Camargo Junior

    2012-09-01

    Full Text Available A new trend in cosmetic formulations is the use of biotechnological raw materials as the polysaccharides from Klebsiella pneumoniae, which are supposed to enhance cell renewal, improve skin hydration and micro-relief. Botanical extracts of Myrtus communis leaves contain different sugars, which may provide the same benefits. Thus, the objective of this study was to evaluate through objective and subjective analysis the immediate and long-term effects of cosmetic formulations containing polysaccharides biotechnologically-originated and / or the ones contained in Myrtus communis extracts. Three polysaccharide-based and placebo formulations were applied on the forearm skin of 40 volunteers. Skin hydration, transepidermal water loss (TEWL, viscoelasticity and skin micro-relief measurements were made before and 2 hours after a single application and after 15 and 30 day-periods of daily applications. Answers to a questionnaire about perceptions of formulation cosmetic features constituted the subjective analysis. All polysaccharide-based formulations enhanced skin hydration. Formulations with isolated or combined active substances improved skin barrier function as compared to placebo, in the short and long term studies. Formulations containing Myrtus communis extracts had the highest acceptance. Results suggest that daily use of formulations containing these substances is important for protection of the skin barrier function.Uma nova tendência em formulações cosméticas é a utilização de matérias-primas biotecnológicas como os polissacarídeos de Klebsiella pneumoniae, que pode aumentar a renovação celular e melhor a hidratação e micro-relevo da pele. Por outro lado, o extrato vegetal de Myrtus communis contém diferentes polissacarídeos, que também podem proporcionar benefícios à pele. Assim, o objetivo do estudo foi a avaliação dos efeitos imediatos e em longo prazo, de formulações cosméticas contendo polissacarídeos obtidos por

  20. Nanoparticle-based photodynamic therapy on non-melanoma skin cancer

    Science.gov (United States)

    Fanjul-Vélez, F.; Arce-Diego, J. L.

    2018-02-01

    There are several advantages of Photodynamic Therapy (PDT) for nonmelanoma skin cancer treatment compared to conventional treatment techniques such as surgery, radiotherapy or chemotherapy. Among these advantages its noninvasive nature, the use of non ionizing radiation and its high selectivity can be mentioned. Despite all these advantages, the therapeutic efficiency of the current clinical protocol is not complete in all the patients and depends on the type of pathology. An adequate dosimetry is needed in order to personalize the protocol. There are strategies that try to overcome the current PDT shortcomings, such as the improvement of the photosensitizer accumulation in the target tissue, optical radiation distribution optimization or photochemical reactions maximization. These strategies can be further complemented by the use of nanostructures with conventional PDT. Customized dosimetry for nanoparticle-based PDT requires models in order to adjust parameters of different nature to get an optimal tumor removal. In this work, a predictive model of nanoparticle-based PDT is proposed and analyzed. Dosimetry in nanoparticle-based PDT is going to be influenced by photosensitizer-nanoparticle distribution in the malignant tissue, its influence in the optical radiation distribution and the subsequent photochemical reactions. Nanoparticles are considered as photosensitizer carriers on several types of non-melanoma skin cancer. Shielding effects are taken into account. The results allow to compare the estimated treatment outcome with and without nanoparticles.

  1. Sensitivity studies for a space-based methane lidar mission

    Directory of Open Access Journals (Sweden)

    C. Kiemle

    2011-10-01

    Full Text Available Methane is the third most important greenhouse gas in the atmosphere after water vapour and carbon dioxide. A major handicap to quantify the emissions at the Earth's surface in order to better understand biosphere-atmosphere exchange processes and potential climate feedbacks is the lack of accurate and global observations of methane. Space-based integrated path differential absorption (IPDA lidar has potential to fill this gap, and a Methane Remote Lidar Mission (MERLIN on a small satellite in polar orbit was proposed by DLR and CNES in the frame of a German-French climate monitoring initiative. System simulations are used to identify key performance parameters and to find an advantageous instrument configuration, given the environmental, technological, and budget constraints. The sensitivity studies use representative averages of the atmospheric and surface state to estimate the measurement precision, i.e. the random uncertainty due to instrument noise. Key performance parameters for MERLIN are average laser power, telescope size, orbit height, surface reflectance, and detector noise. A modest-size lidar instrument with 0.45 W average laser power and 0.55 m telescope diameter on a 506 km orbit could provide 50-km averaged methane column measurement along the sub-satellite track with a precision of about 1% over vegetation. The use of a methane absorption trough at 1.65 μm improves the near-surface measurement sensitivity and vastly relaxes the wavelength stability requirement that was identified as one of the major technological risks in the pre-phase A studies for A-SCOPE, a space-based IPDA lidar for carbon dioxide at the European Space Agency. Minimal humidity and temperature sensitivity at this wavelength position will enable accurate measurements in tropical wetlands, key regions with largely uncertain methane emissions. In contrast to actual passive remote sensors, measurements in Polar Regions will be possible and biases due to aerosol

  2. Correlation between endogenous glutathione content and sensitivity of cultured human skin cells to radiation at defined wavelengths in the solar ultraviolet range

    International Nuclear Information System (INIS)

    Tyrrell, R.M.; Pidoux, M.

    1988-01-01

    Glutathione depletion of cultured human skin fibroblasts by treatment with buthionine-S.R.-sulfoximine (BSO) sensitises them to solar UV radiation. We now show that there is a close quantitative correlation between cellular glutathione content and sensitivity to radiation at 365 nm. A weaker correlation is observed when cells are depleted of glutathione using diethylmaleimide. Both fibroblasts and epidermal keratinocytes derived from the same foreskin biopsy are sensitised to radiation at 313 nm by glutathione depletion. At low to intermediate fluence levels, 10 mM cysteamine present during irradiation at 302 nm is able to almost completely reverse the sensitising effects of glutathione depletion suggesting that the endogenous thiol protects against radiation at this wavelength by a free radical scavenging mechanism. At 313 nm, the sensitisation is not reversed by cysteamine suggesting that glutathione plays a more specific role in protection against radiation at longer wavelengths. Xeroderma pigmentosum group A fibroblasts (excision deficient) are also sensitised to radiation at 313 and 365 nm by depletion of glutathione. The results provide further evidence that endogenous glutathione is involved in protecting human skin cells against a wide range of solar radiation damage. (author)

  3. Sensitivity analysis practices: Strategies for model-based inference

    International Nuclear Information System (INIS)

    Saltelli, Andrea; Ratto, Marco; Tarantola, Stefano; Campolongo, Francesca

    2006-01-01

    Fourteen years after Science's review of sensitivity analysis (SA) methods in 1989 (System analysis at molecular scale, by H. Rabitz) we search Science Online to identify and then review all recent articles having 'sensitivity analysis' as a keyword. In spite of the considerable developments which have taken place in this discipline, of the good practices which have emerged, and of existing guidelines for SA issued on both sides of the Atlantic, we could not find in our review other than very primitive SA tools, based on 'one-factor-at-a-time' (OAT) approaches. In the context of model corroboration or falsification, we demonstrate that this use of OAT methods is illicit and unjustified, unless the model under analysis is proved to be linear. We show that available good practices, such as variance based measures and others, are able to overcome OAT shortcomings and easy to implement. These methods also allow the concept of factors importance to be defined rigorously, thus making the factors importance ranking univocal. We analyse the requirements of SA in the context of modelling, and present best available practices on the basis of an elementary model. We also point the reader to available recipes for a rigorous SA

  4. Sensitivity analysis practices: Strategies for model-based inference

    Energy Technology Data Exchange (ETDEWEB)

    Saltelli, Andrea [Institute for the Protection and Security of the Citizen (IPSC), European Commission, Joint Research Centre, TP 361, 21020 Ispra (Vatican City State, Holy See,) (Italy)]. E-mail: andrea.saltelli@jrc.it; Ratto, Marco [Institute for the Protection and Security of the Citizen (IPSC), European Commission, Joint Research Centre, TP 361, 21020 Ispra (VA) (Italy); Tarantola, Stefano [Institute for the Protection and Security of the Citizen (IPSC), European Commission, Joint Research Centre, TP 361, 21020 Ispra (VA) (Italy); Campolongo, Francesca [Institute for the Protection and Security of the Citizen (IPSC), European Commission, Joint Research Centre, TP 361, 21020 Ispra (VA) (Italy)

    2006-10-15

    Fourteen years after Science's review of sensitivity analysis (SA) methods in 1989 (System analysis at molecular scale, by H. Rabitz) we search Science Online to identify and then review all recent articles having 'sensitivity analysis' as a keyword. In spite of the considerable developments which have taken place in this discipline, of the good practices which have emerged, and of existing guidelines for SA issued on both sides of the Atlantic, we could not find in our review other than very primitive SA tools, based on 'one-factor-at-a-time' (OAT) approaches. In the context of model corroboration or falsification, we demonstrate that this use of OAT methods is illicit and unjustified, unless the model under analysis is proved to be linear. We show that available good practices, such as variance based measures and others, are able to overcome OAT shortcomings and easy to implement. These methods also allow the concept of factors importance to be defined rigorously, thus making the factors importance ranking univocal. We analyse the requirements of SA in the context of modelling, and present best available practices on the basis of an elementary model. We also point the reader to available recipes for a rigorous SA.

  5. Variance decomposition-based sensitivity analysis via neural networks

    International Nuclear Information System (INIS)

    Marseguerra, Marzio; Masini, Riccardo; Zio, Enrico; Cojazzi, Giacomo

    2003-01-01

    This paper illustrates a method for efficiently performing multiparametric sensitivity analyses of the reliability model of a given system. These analyses are of great importance for the identification of critical components in highly hazardous plants, such as the nuclear or chemical ones, thus providing significant insights for their risk-based design and management. The technique used to quantify the importance of a component parameter with respect to the system model is based on a classical decomposition of the variance. When the model of the system is realistically complicated (e.g. by aging, stand-by, maintenance, etc.), its analytical evaluation soon becomes impractical and one is better off resorting to Monte Carlo simulation techniques which, however, could be computationally burdensome. Therefore, since the variance decomposition method requires a large number of system evaluations, each one to be performed by Monte Carlo, the need arises for possibly substituting the Monte Carlo simulation model with a fast, approximated, algorithm. Here we investigate an approach which makes use of neural networks appropriately trained on the results of a Monte Carlo system reliability/availability evaluation to quickly provide with reasonable approximation, the values of the quantities of interest for the sensitivity analyses. The work was a joint effort between the Department of Nuclear Engineering of the Polytechnic of Milan, Italy, and the Institute for Systems, Informatics and Safety, Nuclear Safety Unit of the Joint Research Centre in Ispra, Italy which sponsored the project

  6. Towards highly sensitive strain sensing based on nanostructured materials

    International Nuclear Information System (INIS)

    Dao, Dzung Viet; Nakamura, Koichi; Sugiyama, Susumu; Bui, Tung Thanh; Dau, Van Thanh; Yamada, Takeo; Hata, Kenji

    2010-01-01

    This paper presents our recent theoretical and experimental study of piezo-effects in nanostructured materials for highly sensitive, high resolution mechanical sensors. The piezo-effects presented here include the piezoresistive effect in a silicon nanowire (SiNW) and single wall carbon nanotube (SWCNT) thin film, as well as the piezo-optic effect in a Si photonic crystal (PhC) nanocavity. Firstly, the electronic energy band structure of the silicon nanostructure is discussed and simulated by using the First-Principles Calculations method. The result showed a remarkably different energy band structure compared with that of bulk silicon. This difference in the electronic state will result in different physical, chemical, and therefore, sensing properties of silicon nanostructures. The piezoresistive effects of SiNW and SWCNT thin film were investigated experimentally. We found that, when the width of ( 110 ) p-type SiNW decreases from 500 to 35 nm, the piezoresistive effect increases by more than 60%. The longitudinal piezoresistive coefficient of SWCNT thin film was measured to be twice that of bulk p-type silicon. Finally, theoretical investigations of the piezo-optic effect in a PhC nanocavity based on Finite Difference Time Domain (FDTD) showed extremely high resolution strain sensing. These nanostructures were fabricated based on top-down nanofabrication technology. The achievements of this work are significant for highly sensitive, high resolution and miniaturized mechanical sensors

  7. Investigation of graphene-based nanoscale radiation sensitive materials

    Science.gov (United States)

    Robinson, Joshua A.; Wetherington, Maxwell; Hughes, Zachary; LaBella, Michael, III; Bresnehan, Michael

    2012-06-01

    Current state-of-the-art nanotechnology offers multiple benefits for radiation sensing applications. These include the ability to incorporate nano-sized radiation indicators into widely used materials such as paint, corrosion-resistant coatings, and ceramics to create nano-composite materials that can be widely used in everyday life. Additionally, nanotechnology may lead to the development of ultra-low power, flexible detection systems that can be embedded in clothing or other systems. Graphene, a single layer of graphite, exhibits exceptional electronic and structural properties, and is being investigated for high-frequency devices and sensors. Previous work indicates that graphene-oxide (GO) - a derivative of graphene - exhibits luminescent properties that can be tailored based on chemistry; however, exploration of graphene-oxide's ability to provide a sufficient change in luminescent properties when exposed to gamma or neutron radiation has not been carried out. We investigate the mechanisms of radiation-induced chemical modifications and radiation damage induced shifts in luminescence in graphene-oxide materials to provide a fundamental foundation for further development of radiation sensitive detection architectures. Additionally, we investigate the integration of hexagonal boron nitride (hBN) with graphene-based devices to evaluate radiation induced conductivity in nanoscale devices. Importantly, we demonstrate the sensitivity of graphene transport properties to the presence of alpha particles, and discuss the successful integration of hBN with large area graphene electrodes as a means to provide the foundation for large-area nanoscale radiation sensors.

  8. Cultivar Diversity of Grape Skin Polyphenol Composition and Changes in Response to Drought Investigated by LC-MS Based Metabolomics

    Directory of Open Access Journals (Sweden)

    Lucie Pinasseau

    2017-10-01

    Full Text Available Phenolic compounds represent a large family of plant secondary metabolites, essential for the quality of grape and wine and playing a major role in plant defense against biotic and abiotic stresses. Phenolic composition is genetically driven and greatly affected by environmental factors, including water stress. A major challenge for breeding of grapevine cultivars adapted to climate change and with high potential for wine-making is to dissect the complex plant metabolic response involved in adaptation mechanisms. A targeted metabolomics approach based on ultra high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QqQ-MS analysis in the Multiple Reaction Monitoring (MRM mode has been developed for high throughput profiling of the phenolic composition of grape skins. This method enables rapid, selective, and sensitive quantification of 96 phenolic compounds (anthocyanins, phenolic acids, stilbenoids, flavonols, dihydroflavonols, flavan-3-ol monomers, and oligomers…, and of the constitutive units of proanthocyanidins (i.e., condensed tannins, giving access to detailed polyphenol composition. It was applied on the skins of mature grape berries from a core-collection of 279 Vitis vinifera cultivars grown with or without watering to assess the genetic variation for polyphenol composition and its modulation by irrigation, in two successive vintages (2014–2015. Distribution of berry weights and δ13C values showed that non irrigated vines were subjected to a marked water stress in 2014 and to a very limited one in 2015. Metabolomics analysis of the polyphenol composition and chemometrics analysis of this data demonstrated an influence of water stress on the biosynthesis of different polyphenol classes and cultivar differences in metabolic response to water deficit. Correlation networks gave insight on the relationships between the different polyphenol metabolites and related biosynthetic pathways. They also

  9. Perceived Relevance of Educative Information on Public (Skin Health: Results of a Representative, Population-Based Telephone Survey

    Directory of Open Access Journals (Sweden)

    Daniela Haluza

    2015-11-01

    Full Text Available Individual skin health attitudes are influenced by various factors, including public education campaigns, mass media, family, and friends. Evidence-based, educative information materials assist communication and decision-making in doctor-patient interactions. The present study aims at assessing the prevailing use of skin health information material and sources and their impact on skin health knowledge, motives to tan, and sun protection. We conducted a questionnaire survey among a representative sample of Austrian residents. Print media and television were perceived as the two most relevant sources for skin health information, whereas the source physician was ranked third. Picking the information source physician increased participants’ skin health knowledge (p = 0.025 and sun-protective behavior (p < 0.001. The study results highlight the demand for targeted health messages to attain lifestyle changes towards photo-protective habits. Providing resources that encourage pro-active counseling in every-day doctor-patient communication could increase skin health knowledge and sun-protective behavior, and thus, curb the rise in skin cancer incidence rates.

  10. Accounting for data variability, a key factor in in vivo/in vitro relationships: application to the skin sensitization potency (in vivo LLNA versus in vitro DPRA) example.

    Science.gov (United States)

    Dimitrov, S; Detroyer, A; Piroird, C; Gomes, C; Eilstein, J; Pauloin, T; Kuseva, C; Ivanova, H; Popova, I; Karakolev, Y; Ringeissen, S; Mekenyan, O

    2016-12-01

    When searching for alternative methods to animal testing, confidently rescaling an in vitro result to the corresponding in vivo classification is still a challenging problem. Although one of the most important factors affecting good correlation is sample characteristics, they are very rarely integrated into correlation studies. Usually, in these studies, it is implicitly assumed that both compared values are error-free numbers, which they are not. In this work, we propose a general methodology to analyze and integrate data variability and thus confidence estimation when rescaling from one test to another. The methodology is demonstrated through the case study of rescaling the in vitro Direct Peptide Reactivity Assay (DPRA) reactivity to the in vivo Local Lymph Node Assay (LLNA) skin sensitization potency classifications. In a first step, a comprehensive statistical analysis evaluating the reliability and variability of LLNA and DPRA as such was done. These results allowed us to link the concept of gray zones and confidence probability, which in turn represents a new perspective for a more precise knowledge of the classification of chemicals within their in vivo OR in vitro test. Next, the novelty and practical value of our methodology introducing variability into the threshold optimization between the in vitro AND in vivo test resides in the fact that it attributes a confidence probability to the predicted classification. The methodology, classification and screening approach presented in this study are not restricted to skin sensitization only. They could be helpful also for fate, toxicity and health hazard assessment where plenty of in vitro and in chemico assays and/or QSARs models are available. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Predicting skin sensitization potential and inter-laboratory reproducibility of a human Cell Line Activation Test (h-CLAT) in the European Cosmetics Association (COLIPA) ring trials.

    Science.gov (United States)

    Sakaguchi, Hitoshi; Ryan, Cindy; Ovigne, Jean-Marc; Schroeder, Klaus R; Ashikaga, Takao

    2010-09-01

    Regulatory policies in Europe prohibited the testing of cosmetic ingredients in animals for a number of toxicological endpoints. Currently no validated non-animal test methods exist for skin sensitization. Evaluation of changes in cell surface marker expression in dendritic cell (DC)-surrogate cell lines represents one non-animal approach. The human Cell Line Activation Test (h-CLAT) examines the level of CD86 and CD54 expression on the surface of THP-1 cells, a human monocytic leukemia cell line, following 24h of chemical exposure. To examine protocol transferability, between-lab reproducibility, and predictive capacity, the h-CLAT has been evaluated by five independent laboratories in several ring trials (RTs) coordinated by the European Cosmetics Association (COLIPA). The results of the first and second RTs demonstrated that the protocol was transferable and basically had good between-lab reproducibility and predictivity, but there were some false negative data. To improve performance, protocol and prediction model were modified. Using the modified prediction model in the first and second RT, accuracy was improved. However, about 15% of the outcomes were not correctly identified, which exposes some of the limitations of the assay. For the chemicals evaluated, the limitation may due to chemical being a weak allergen or having low solubility (ex. alpha-hexylcinnamaldehyde). The third RT evaluated the modified prediction model and satisfactory results were obtained. From the RT data, the feasibility of utilizing cell lines as surrogate DC in development of in vitro skin sensitization methods shows promise. The data also support initiating formal pre-validation of the h-CLAT in order to fully understand the capabilities and limitations of the assay. Copyright 2010 Elsevier Ltd. All rights reserved.

  12. Primary mucinous carcinoma of the skin: a population-based study

    DEFF Research Database (Denmark)

    Breiting, L.; Dahlstrom, K.; Breiting, V.

    2008-01-01

    Background Primary mucinous carcinoma of the skin (PMCS) is a rare malignant tumor deriving from the sweat glands. It is typically located on the head and is often mistaken for a metastasis from a more common primary tumor of the breast or gastrointestinal tract. We present the first population......-based study of PMCS. Materials and methods Data on PMCS was obtained from the Danish Cancer Registry, which has recorded incident cases of cancer on a nationwide basis since 1943. We extracted all patients diagnosed 1978-2003 with PMCS. Results Fifteen cases of PMCS have been registered during the study...... or PMCS related deaths were reported. Conclusion PMCS is a rare, slow-growing tumor which rarely metastasizes and is associated with low mortality. The age-standardized incidence rate, based on data from a population-based cancer registry of high quality and validity, is less than 0.1 per million. However...

  13. Sensitive determination of citrinin based on molecular imprinted electrochemical sensor

    Energy Technology Data Exchange (ETDEWEB)

    Atar, Necip [Department of Chemical Engineering, Faculty of Engineering, Pamukkale University, Denizli (Turkey); Yola, Mehmet Lütfi, E-mail: mehmetyola@gmail.com [Department of Metallurgical and Materials Engineering, Faculty of Engineering, Sinop University, Sinop (Turkey); Eren, Tanju [Department of Chemical Engineering, Faculty of Engineering, Pamukkale University, Denizli (Turkey)

    2016-01-30

    Graphical abstract: - Highlights: • Citrinin-imprinted electrochemical sensor is developed for the sensitive detection of citrinin. • The nanomaterial and citrinin-imprinted surfaces were characterized by several methods. • Citrinin-imprinted electrochemical sensor is sensitive and selective in analysis of food. • Citrinin-imprinted electrochemical sensor is preferred to the other methods. - Abstract: In this report, a novel molecular imprinted voltammetric sensor based on glassy carbon electrode (GCE) modified with platinum nanoparticles (PtNPs) involved in a polyoxometalate (H{sub 3}PW{sub 12}O{sub 40}, POM) functionalized reduced graphene oxide (rGO) was prepared for the determination of citrinin (CIT). The developed surfaces were characterized by using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) method. CIT imprinted GCE was prepared via electropolymerization process of 80.0 mM pyrrole as monomer in the presence of phosphate buffer solution (pH 6.0) containing 20.0 mM CIT. The linearity range and the detection limit of the developed method were calculated as 1.0 × 10{sup −12}–1.0 × 10{sup −10} M and 2.0 × 10{sup −13} M, respectively. In addition, the voltammetric sensor was applied to rye samples. The stability and selectivity of the voltammetric sensor were also reported.

  14. Sensitive determination of citrinin based on molecular imprinted electrochemical sensor

    International Nuclear Information System (INIS)

    Atar, Necip; Yola, Mehmet Lütfi; Eren, Tanju

    2016-01-01

    Graphical abstract: - Highlights: • Citrinin-imprinted electrochemical sensor is developed for the sensitive detection of citrinin. • The nanomaterial and citrinin-imprinted surfaces were characterized by several methods. • Citrinin-imprinted electrochemical sensor is sensitive and selective in analysis of food. • Citrinin-imprinted electrochemical sensor is preferred to the other methods. - Abstract: In this report, a novel molecular imprinted voltammetric sensor based on glassy carbon electrode (GCE) modified with platinum nanoparticles (PtNPs) involved in a polyoxometalate (H_3PW_1_2O_4_0, POM) functionalized reduced graphene oxide (rGO) was prepared for the determination of citrinin (CIT). The developed surfaces were characterized by using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) method. CIT imprinted GCE was prepared via electropolymerization process of 80.0 mM pyrrole as monomer in the presence of phosphate buffer solution (pH 6.0) containing 20.0 mM CIT. The linearity range and the detection limit of the developed method were calculated as 1.0 × 10"−"1"2–1.0 × 10"−"1"0 M and 2.0 × 10"−"1"3 M, respectively. In addition, the voltammetric sensor was applied to rye samples. The stability and selectivity of the voltammetric sensor were also reported.

  15. Cross-covariance based global dynamic sensitivity analysis

    Science.gov (United States)

    Shi, Yan; Lu, Zhenzhou; Li, Zhao; Wu, Mengmeng

    2018-02-01

    For identifying the cross-covariance source of dynamic output at each time instant for structural system involving both input random variables and stochastic processes, a global dynamic sensitivity (GDS) technique is proposed. The GDS considers the effect of time history inputs on the dynamic output. In the GDS, the cross-covariance decomposition is firstly developed to measure the contribution of the inputs to the output at different time instant, and an integration of the cross-covariance change over the specific time interval is employed to measure the whole contribution of the input to the cross-covariance of output. Then, the GDS main effect indices and the GDS total effect indices can be easily defined after the integration, and they are effective in identifying the important inputs and the non-influential inputs on the cross-covariance of output at each time instant, respectively. The established GDS analysis model has the same form with the classical ANOVA when it degenerates to the static case. After degeneration, the first order partial effect can reflect the individual effects of inputs to the output variance, and the second order partial effect can reflect the interaction effects to the output variance, which illustrates the consistency of the proposed GDS indices and the classical variance-based sensitivity indices. The MCS procedure and the Kriging surrogate method are developed to solve the proposed GDS indices. Several examples are introduced to illustrate the significance of the proposed GDS analysis technique and the effectiveness of the proposed solution.

  16. Topological sensitivity based far-field detection of elastic inclusions

    Directory of Open Access Journals (Sweden)

    Tasawar Abbas

    2018-03-01

    Full Text Available The aim of this article is to present and rigorously analyze topological sensitivity based algorithms for detection of diametrically small inclusions in an isotropic homogeneous elastic formation using single and multiple measurements of the far-field scattering amplitudes. A L2-cost functional is considered and a location indicator is constructed from its topological derivative. The performance of the indicator is analyzed in terms of the topological sensitivity for location detection and stability with respect to measurement and medium noises. It is established that the location indicator does not guarantee inclusion detection and achieves only a low resolution when there is mode-conversion in an elastic formation. Accordingly, a weighted location indicator is designed to tackle the mode-conversion phenomenon. It is substantiated that the weighted function renders the location of an inclusion stably with resolution as per Rayleigh criterion. 2000 MSC: 35R30, 35L05, 74B05, 47A52, 65J20, Keywords: Inverse elastic scattering, Elasticity imaging, Topological derivative, Resolution analysis, Stability analysis

  17. A sensitive, handheld vapor sensor based on microcantilevers

    Science.gov (United States)

    Pinnaduwage, L. A.; Hedden, D. L.; Gehl, A.; Boiadjiev, V. I.; Hawk, J. E.; Farahi, R. H.; Thundat, T.; Houser, E. J.; Stepnowski, S.; McGill, R. A.; Deel, L.; Lareau, R. T.

    2004-11-01

    We report the development of a handheld sensor based on piezoresistive microcantilevers that does not depend on optical detection, yet has high detection sensitivity. The sensor is able to detect vapors from the plastic explosives pentaerythritol tetranitrate and hexahydro-1,3,5-triazine at levels below 10 parts per trillion within few seconds of exposure under ambient conditions. A differential measurement technique has yielded a rugged sensor that is unaffected by vibration and is able to function as a "sniffer." The microelectromechanical system sensor design allows for the incorporation of hundreds of microcantilevers with suitable coatings in order to achieve sufficient selectivity in the future, and thus could provide an inexpensive, unique platform for the detection of chemical, biological, and explosive materials.

  18. Solar cells with perovskite-based light sensitization layers

    Science.gov (United States)

    Kanatzidis, Mercouri G.; Chang, Robert P.H.; Stoumpos, Konstantinos; Lee, Byunghong

    2018-05-08

    Solar cells are provided which comprise an electron transporting layer and a light sensitizing layer of perovskite disposed over the surface of the electron transporting layer. The perovskite may have a formula selected from the group consisting of A2MX6, Z2MX6 or YMX6, wherein A is an alkali metal, M is a metal or a metalloid, X is a halide, Z is selected from the group consisting of a primary ammonium, an iminium, a secondary ammonium, a tertiary ammonium, and a quaternary ammonium, and Y has formula Mb(L)3, wherein Mb is a transition metal in the 2+ oxidation state L is an N--N neutral chelating ligand. Methods of making the solar cells are also provided, including methods based on electrospray deposition.

  19. Context sensitivity and ambiguity in component-based systems design

    Energy Technology Data Exchange (ETDEWEB)

    Bespalko, S.J.; Sindt, A.

    1997-10-01

    Designers of components-based, real-time systems need to guarantee to correctness of soft-ware and its output. Complexity of a system, and thus the propensity for error, is best characterized by the number of states a component can encounter. In many cases, large numbers of states arise where the processing is highly dependent on context. In these cases, states are often missed, leading to errors. The following are proposals for compactly specifying system states which allow the factoring of complex components into a control module and a semantic processing module. Further, the need for methods that allow for the explicit representation of ambiguity and uncertainty in the design of components is discussed. Presented herein are examples of real-world problems which are highly context-sensitive or are inherently ambiguous.

  20. One-dimensional position sensitive detector based on photonic crystals

    International Nuclear Information System (INIS)

    Xi Feng; Qin Lan; Xue Lian; Duan Ying

    2013-01-01

    Position sensitive detectors (PSDs) are an important class of optical sensors which utilizes the lateral photovoltaic effect (LPVE). According to the operation principle of PSD, we demonstrate that LPVE can be enhanced by lengthening the lifetime of photo-generated carriers. A PSD based on photonic crystals (PCs) composed of MgF 2 and InP is proposed and designed. The transmittances of the defect PC and the reflectance of the perfect PC in the PSD are obtained with transfer matrix method. The theoretical research on the designed device shows that LPVE is enhanced by improving the transmittance of the defect PC and the reflectance of the perfect PC to lengthen the lifetime of photo-generated carriers. (authors)

  1. Your Skin

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Your Skin KidsHealth / For Kids / Your Skin What's in this ... body) are really dead skin cells. Bye-Bye Skin Cells These old cells are tough and strong, ...

  2. A Deformable Smart Skin for Continuous Sensing Based on Electrical Impedance Tomography.

    Science.gov (United States)

    Visentin, Francesco; Fiorini, Paolo; Suzuki, Kenji

    2016-11-16

    In this paper, we present a low-cost, adaptable, and flexible pressure sensor that can be applied as a smart skin over both stiff and deformable media. The sensor can be easily adapted for use in applications related to the fields of robotics, rehabilitation, or costumer electronic devices. In order to remove most of the stiff components that block the flexibility of the sensor, we based the sensing capability on the use of a tomographic technique known as Electrical Impedance Tomography. The technique allows the internal structure of the domain under study to be inferred by reconstructing its conductivity map. By applying the technique to a material that changes its resistivity according to applied forces, it is possible to identify these changes and then localise the area where the force was applied. We tested the system when applied to flat and curved surfaces. For all configurations, we evaluate the artificial skin capabilities to detect forces applied over a single point, over multiple points, and changes in the underlying geometry. The results are all promising, and open the way for the application of such sensors in different robotic contexts where deformability is the key point.

  3. Performance Based Envelopes: A Theory of Spatialized Skins and the Emergence of the Integrated Design Professional

    Directory of Open Access Journals (Sweden)

    Franca Trubiano

    2013-10-01

    Full Text Available Realigning the design of building envelopes within the measures of air, light and heat has rendered possible an inventive form of practice whose benefits are far in excess of the metrics of data and analysis. For many of its most advanced practitioners, the contemporary design of facades engages the true potential of “performance” when it deepens, broadens and complicates the theoretical dimension of this most liminal of surfaces. Of particular interest to this paper is a discussion of new theoretical paradigms associated with the design and operation of high performance envelopes of which four characteristics of this emergent sub-discipline are herein examined. To begin with, the way in which building envelopes are no longer separators, dividers and barriers between a building’s interior and exterior conditions, but rather, “spatially” defined environments that fully engage the totality of a building’s engineering systems, is discussed. Cantilevered Louvers, Double Skin Facades and Hybrid Conditioned Atria are representative of this new paradigm as is the use of Responsive Technologies to optimize their behaviors. Lastly, the paper examines the rise of the new integrated design building envelope professional called upon to deliver ever-better performing skins, whether in the guise of energy modeler, climate engineer or façade construction specialist. Hence, this paper develops a theoretical structure within which to describe, analyze and interpret the values made possible by this new and expanding field of performance based envelopes.

  4. Skin cancer preventive behaviors among rural farmers: An intervention based on protection motivation theory.

    Science.gov (United States)

    Babazadeh, Towhid; Kamran, Aziz; Dargahi, Abdollah; Moradi, Fatemeh; Shariat, Fariba; Rezakhani Moghaddam, Hamed

    2016-01-01

    Background: Skin cancer is a serious public health problem in the world. Its prevalence in many countries has been increased in recent years. This study aimed to assess the effects of a theory-based educational intervention to promote skin cancer preventive behaviors (SCPBs) among rural farmers in Chalderan County, Iran. Methods: This was a quasi-randomized controlled field trial study conducted on 238 rural farmers. The data were collected by a questionnaire containing the constructs of the Protection Motivation Theory (PMT) as well as the items of SCPBs. The differences between the groups before and 3 months after the intervention were determined by independent t-test, paired t-test, and chi-square applying SPSS software. Results: Before the intervention, no significant difference was found in the scores of the PMT constructs between the two groups (p>0.05). However, significant differences were found between the scores of all the variables, as well as SCPBs, in the two groups after the intervention (p<0.05). Conclusion: The PMT was found to be an appropriate framework for designing educational interventions aiming at promoting SCPBs among rural farmers. It was concluded that designing an educational program with a focus on promoting perceived susceptibility increased the level of performing SCPBs among the rural farmers.

  5. Long-term repeatability of the skin prick test is high when supported by history or allergen-sensitivity tests

    DEFF Research Database (Denmark)

    Bødtger, Uffe; Jacobsen, C R; Poulsen, L K

    2003-01-01

    subjects. An SPT was positive when > or =3 mm, and repeatable if either persistently positive or negative. Clinical sensitivity to birch pollen was used as model for inhalation allergy, and was investigated at inclusion and at study termination by challenge tests, intradermal test, titrated SPT and Ig......E measurements. Birch pollen symptoms were confirmed in diaries. RESULTS: The repeatability of a positive SPT was 67%, increasing significantly to 100% when supported by the history. When not supported by history, the presence of specific IgE was significantly associated with a repeatable SPT. Allergen....... CONCLUSION: SPT changes are clinically relevant. Further studies using other allergens are needed. Long-term repeatability of SPT is high in the presence of a supportive history....

  6. Sensitization to cereals and peanut evidenced by skin prick test and specific IgE in food-tolerant, grass pollen allergic patients

    Directory of Open Access Journals (Sweden)

    Martens Maria

    2011-12-01

    Full Text Available Abstract Background The botanical relation between grass and cereal grains may be relevant when diagnosing food allergy to cereals. The aim was to investigate the diagnostic specificity of skin prick test (SPT and specific immunoglobulin E (sIgE tests to cereals and peanut in grass pollen allergic subjects without history of, and clinically reactions to foods botanically related to grass. Methods 70 subjects (41 females; mean age 32 years and 20 healthy controls (13 females; mean age 24 years were tested by open food challenge (OFC with cereals and peanut. SPT and sIgE both with Immulite® (Siemens and ImmunoCAP® (Phadia to grass and birch pollen, cereals, peanut and bromelain were performed. Results Of the 65 OFC-negative subjects 29-46% (SPT, depending on cut-off, 20% (Immulite and 38% (ImmunoCAP had positive results to one or more of the foods tested. Controls were negative in all tests. Cross-reactive carbohydrate determinants (CCD as evidenced by reaction to bromelain could explain only a minority of the measured IgE-sensitizations. Conclusion Grass pollen allergic patients with documented food tolerance to cereals and peanut may express significant sensitization. False-positive cereal or peanut allergy diagnoses may be a quantitatively important problem both in routine clinical work and epidemiological studies.

  7. UV Radiation and the Skin

    Directory of Open Access Journals (Sweden)

    Timothy Scott

    2013-06-01

    Full Text Available UV radiation (UV is classified as a “complete carcinogen” because it is both a mutagen and a non-specific damaging agent and has properties of both a tumor initiator and a tumor promoter. In environmental abundance, UV is the most important modifiable risk factor for skin cancer and many other environmentally-influenced skin disorders. However, UV also benefits human health by mediating natural synthesis of vitamin D and endorphins in the skin, therefore UV has complex and mixed effects on human health. Nonetheless, excessive exposure to UV carries profound health risks, including atrophy, pigmentary changes, wrinkling and malignancy. UV is epidemiologically and molecularly linked to the three most common types of skin cancer, basal cell carcinoma, squamous cell carcinoma and malignant melanoma, which together affect more than a million Americans annually. Genetic factors also influence risk of UV-mediated skin disease. Polymorphisms of the melanocortin 1 receptor (MC1R gene, in particular, correlate with fairness of skin, UV sensitivity, and enhanced cancer risk. We are interested in developing UV-protective approaches based on a detailed understanding of molecular events that occur after UV exposure, focusing particularly on epidermal melanization and the role of the MC1R in genome maintenance.

  8. Long ranging swept-source optical coherence tomography-based angiography outperforms its spectral-domain counterpart in imaging human skin microcirculations

    Science.gov (United States)

    Xu, Jingjiang; Song, Shaozhen; Men, Shaojie; Wang, Ruikang K.

    2017-11-01

    There is an increasing demand for imaging tools in clinical dermatology that can perform in vivo wide-field morphological and functional examination from surface to deep tissue regions at various skin sites of the human body. The conventional spectral-domain optical coherence tomography-based angiography (SD-OCTA) system is difficult to meet these requirements due to its fundamental limitations of the sensitivity roll-off, imaging range as well as imaging speed. To mitigate these issues, we demonstrate a swept-source OCTA (SS-OCTA) system by employing a swept source based on a vertical cavity surface-emitting laser. A series of comparisons between SS-OCTA and SD-OCTA are conducted. Benefiting from the high system sensitivity, long imaging range, and superior roll-off performance, the SS-OCTA system is demonstrated with better performance in imaging human skin than the SD-OCTA system. We show that the SS-OCTA permits remarkable deep visualization of both structure and vasculature (up to ˜2 mm penetration) with wide field of view capability (up to 18×18 mm2), enabling a more comprehensive assessment of the morphological features as well as functional blood vessel networks from the superficial epidermal to deep dermal layers. It is expected that the advantages of the SS-OCTA system will provide a ground for clinical translation, benefiting the existing dermatological practice.

  9. Computer Breakdown as a Stress Factor during Task Completion under Time Pressure: Identifying Gender Differences Based on Skin Conductance

    Directory of Open Access Journals (Sweden)

    René Riedl

    2013-01-01

    Full Text Available In today’s society, as computers, the Internet, and mobile phones pervade almost every corner of life, the impact of Information and Communication Technologies (ICT on humans is dramatic. The use of ICT, however, may also have a negative side. Human interaction with technology may lead to notable stress perceptions, a phenomenon referred to as technostress. An investigation of the literature reveals that computer users’ gender has largely been ignored in technostress research, treating users as “gender-neutral.” To close this significant research gap, we conducted a laboratory experiment in which we investigated users’ physiological reaction to the malfunctioning of technology. Based on theories which explain that men, in contrast to women, are more sensitive to “achievement stress,” we predicted that male users would exhibit higher levels of stress than women in cases of system breakdown during the execution of a human-computer interaction task under time pressure, if compared to a breakdown situation without time pressure. Using skin conductance as a stress indicator, the hypothesis was confirmed. Thus, this study shows that user gender is crucial to better understanding the influence of stress factors such as computer malfunctions on physiological stress reactions.

  10. Skin Bleaching and Dermatologic Health of African and Afro-Caribbean Populations in the US: New Directions for Methodologically Rigorous, Multidisciplinary, and Culturally Sensitive Research

    OpenAIRE

    Benn, Emma K. T.; Alexis, Andrew; Mohamed, Nihal; Wang, Yan-Hong; Khan, Ikhlas A.; Liu, Bian

    2016-01-01

    Skin-bleaching practices, such as using skin creams and soaps to achieve a lighter skin tone, are common throughout the world and are triggered by cosmetic reasons that oftentimes have deep historical, economic, sociocultural, and psychosocial roots. Exposure to chemicals in the bleaching products, notably, mercury (Hg), hydroquinone, and steroids, has been associated with a variety of adverse health effects, such as Hg poisoning and exogenous ochronosis. In New York City (NYC), skin care pro...

  11. Non-invasive Oil-Based Method to Increase Topical Delivery of Nucleic Acids to Skin.

    Science.gov (United States)

    Vij, Manika; Alam, Shamshad; Gupta, Nidhi; Gotherwal, Vishvabandhu; Gautam, Hemlata; Ansari, Kausar M; Santhiya, Deenan; Natarajan, Vivek T; Ganguli, Munia

    2017-06-07

    Topical delivery of nucleic acids to skin has huge prospects in developing therapeutic interventions for cutaneous disorders. In spite of initial success, clinical translation is vastly impeded by the constraints of bioavailability as well as stability in metabolically active environment of skin. Various physical and chemical methods used to overcome these limitations involve invasive procedures or compounds that compromise skin integrity. Hence, there is an increasing demand for developing safe skin penetration enhancers for efficient nucleic acid delivery to skin. Here, we demonstrate that pretreatment of skin with silicone oil can increase the transfection efficiency of non-covalently associated peptide-plasmid DNA nanocomplexes in skin ex vivo and in vivo. The method does not compromise skin integrity, as indicated by microscopic evaluation of cellular differentiation, tissue architecture, enzyme activity assessment, dye penetration tests using Franz assay, and cytotoxicity and immunogenicity analyses. Stability of nanocomplexes is not hampered on pretreatment, thereby avoiding nuclease-mediated degradation. The mechanistic insights through Fourier transform infrared (FTIR) spectroscopy reveal some alterations in the skin hydration status owing to possible occlusion effects of the enhancer. Overall, we describe a topical, non-invasive, efficient, and safe method that can be used to increase the penetration and delivery of plasmid DNA to skin for possible therapeutic applications. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  12. Long-term retention of gadolinium in the skin of rodents following the administration of gadolinium-based contrast agents

    International Nuclear Information System (INIS)

    Pietsch, Hubertus; Jost, Gregor; Frenzel, Thomas; Huetter, Joachim; Sieber, Martin A.; Lengsfeld, Philipp

    2009-01-01

    Several publications suggest a potential association between the administration of Gadolinium-based contrast agents (GBCAs) and the onset of a rare but serious disease, Nephrogenic Systemic Fibrosis (NSF). The aim of this study was to determine the elimination time-course of Gadolinium (Gd) from skin tissue after application of GBCAs in rats. Seven different marketed GBCAs were injected on five consecutive days at a dose of 2.5 mmol/kg bodyweight into the tail vein of Han-Wistar rats and the Gd concentrations were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in skin biopsies taken at various time-points up to a year after the last injection. Most of the administered Gd was eliminated from the skin within a time-period of about 2 months. However, the repeated administration of linear GBCAs resulted in long-term retention of a small portion of the administered Gd in the skin tissue of rats, with substantially higher values observed in animals treated with non-ionic linear agents than in those that received ionic linear GBCAs. Following treatment with macrocyclic GBCAs, Gd values in the skin were in the same range as observed in the controls from day 24 post-injection onwards. In summary, we observed a correlation between the complex stability of GBCAs and the amount of residual Gd in the skin up to a year after application of GBCAs. (orig.)

  13. Long-term retention of gadolinium in the skin of rodents following the administration of gadolinium-based contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Pietsch, Hubertus; Jost, Gregor; Frenzel, Thomas; Huetter, Joachim; Sieber, Martin A. [Media Research, Bayer Schering Pharma AG Contrast, Berlin (Germany); Lengsfeld, Philipp [Bayer Schering Pharma AG, Global Medical Affairs Diagnostic Imaging, Berlin (Germany)

    2009-06-15

    Several publications suggest a potential association between the administration of Gadolinium-based contrast agents (GBCAs) and the onset of a rare but serious disease, Nephrogenic Systemic Fibrosis (NSF). The aim of this study was to determine the elimination time-course of Gadolinium (Gd) from skin tissue after application of GBCAs in rats. Seven different marketed GBCAs were injected on five consecutive days at a dose of 2.5 mmol/kg bodyweight into the tail vein of Han-Wistar rats and the Gd concentrations were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in skin biopsies taken at various time-points up to a year after the last injection. Most of the administered Gd was eliminated from the skin within a time-period of about 2 months. However, the repeated administration of linear GBCAs resulted in long-term retention of a small portion of the administered Gd in the skin tissue of rats, with substantially higher values observed in animals treated with non-ionic linear agents than in those that received ionic linear GBCAs. Following treatment with macrocyclic GBCAs, Gd values in the skin were in the same range as observed in the controls from day 24 post-injection onwards. In summary, we observed a correlation between the complex stability of GBCAs and the amount of residual Gd in the skin up to a year after application of GBCAs. (orig.)

  14. Regenerative Skin Wound Healing in Mammals: State-of-the-Art on Growth Factor and Stem Cell Based Treatments

    Directory of Open Access Journals (Sweden)

    Bizunesh M. Borena

    2015-04-01

    Full Text Available Mammal skin has a crucial function in several life-preserving processes such as hydration, protection against chemicals and pathogens, initialization of vitamin D synthesis, excretion and heat regulation. Severe damage of the skin may therefore be life-threatening. Skin wound repair is a multiphased, yet well-orchestrated process including the interaction of various cell types, growth factors and cytokines aiming at closure of the skin and preferably resulting in tissue repair. Regardless various therapeutic modalities targeting at enhancing wound healing, the development of novel approaches for this pathology remains a clinical challenge. The time-consuming conservative wound management is mainly restricted to wound repair rather than restitution of the tissue integrity (the so-called “restitutio ad integrum”. Therefore, there is a continued search towards more efficacious wound therapies to reduce health care burden, provide patients with long-term relief and ultimately scarless wound healing. Recent in vivo and in vitro studies on the use of skin wound regenerative therapies provide encouraging results, but more protracted studies will have to determine whether the effect of observed effects are clinically significant and whether regeneration rather than repair can be achieved. For all the aforementioned reasons, this article reviews the emerging field of regenerative skin wound healing in mammals with particular emphasis on growth factor- and stem cell-based therapies.

  15. Biologic activities of molecular chaperones and pharmacologic chaperone imidazole-containing dipeptide-based compounds: natural skin care help and the ultimate challenge: implication for adaptive responses in the skin.

    Science.gov (United States)

    Babizhayev, Mark A; Nikolayev, Gennady M; Nikolayeva, Juliana G; Yegorov, Yegor E

    2012-03-01

    Accumulation of molecular damage and increased molecular heterogeneity are hallmarks of photoaged skin and pathogenesis of human cutaneous disease. Growing evidence demonstrates the ability of molecular chaperone proteins and of pharmacologic chaperones to decrease the environmental stress and ameliorate the oxidation stress-related and glycation disease phenotypes, suggesting that the field of chaperone therapy might hold novel treatments for skin diseases and aging. In this review, we examine the evidence suggesting a role for molecular chaperone proteins in the skin and their inducer and protecting agents: pharmacologic chaperone imidazole dipeptide-based agents (carcinine and related compounds) in cosmetics and dermatology. Furthermore, we discuss the use of chaperone therapy for the treatment of skin photoaging diseases and other skin pathologies that have a component of increased glycation and/or free radical-induced oxidation in their genesis. We examine biologic activities of molecular and pharmacologic chaperones, including strategies for identifying potential chaperone compounds and for experimentally demonstrating chaperone activity in in vitro and in vivo models of human skin disease. This allows the protein to function and traffic to the appropriate location in the skin, thereby increasing protein activity and cellular function and reducing stress on skin cells. The benefits of imidazole dipeptide antioxidants with transglycating activity (such as carcinine) in skin care are that they help protect and repair cell membrane damage and help retain youthful, younger-looking skin. All skin types will benefit from daily, topical application of pharmacologic chaperone antioxidants, anti-irritants, in combination with water-binding protein agents that work to mimic the structure and function of healthy skin. General strategies are presented addressing ground techniques to improve absorption of usually active chaperone proteins and dipeptide compounds, include

  16. Assessment of dermal exposure and skin condition of workers exposed to nickel at a South African base metal refinery.

    Science.gov (United States)

    Du Plessis, Johannes L; Eloff, Frederik C; Badenhorst, Casper J; Olivier, Johretha; Laubscher, Petrus J; Van Aarde, Michiel N; Franken, Anja

    2010-01-01

    The objectives of this study were to assess dermal exposure of cell workers to nickel at a South African base metal refinery and to characterize their skin condition by measuring the skin hydration and trans epidermal water loss (TEWL) indices. The skin hydration index of the index finger, palm, neck, and forehead was measured before, during and at the end of the shift. The TEWL index was measured before and at the end of the shift. Dermal exposure samples were collected with Ghostwipes from the index finger and palm of the dominant hand, before, during, and at the end of the shift. Neck and forehead samples were collected before and at the end of the shift. Wipe samples of various surfaces in the workplace were also collected. Wipes were analyzed for nickel according to NIOSH method 9102, using inductively coupled plasma-atomic emission spectrometry. Hydration indices measured on the hands decreased significantly during the shift, but recovered to normal levels by the end of the shift. TEWL indices for the index finger and palm of the hands are indicative of a low barrier function even before commencement of the shift, which further deteriorated significantly during the shift. During the shift, substantial nickel skin loading occurred on the index finger and palm of the hand. Levels on the neck and forehead were much lower. Various workplace surfaces, which workers come into contact with, were also contaminated with nickel. The skin condition and high levels of nickel on the skin were most probably caused by inadequate chemical protection provided by protective gloves. Although, the permeability of nickel through intact skin is considered to be low, a decreased barrier function of dehydrated or slightly damaged skin will increase its permeability for nickel. The ethnicity of these exposed workers may contribute significantly toward the low incidence of allergic contact dermatitis observed. Several measures to lower dermal exposure to nickel are also recommended.

  17. Design and Characterization of a Three-Axis Hall Effect-Based Soft Skin Sensor

    Directory of Open Access Journals (Sweden)

    Tito Pradhono Tomo

    2016-04-01

    Full Text Available This paper presents an easy means to produce a 3-axis Hall effect–based skin sensor for robotic applications. It uses an off-the-shelf chip and is physically small and provides digital output. Furthermore, the sensor has a soft exterior for safe interactions with the environment; in particular it uses soft silicone with about an 8 mm thickness. Tests were performed to evaluate the drift due to temperature changes, and a compensation using the integral temperature sensor was implemented. Furthermore, the hysteresis and the crosstalk between the 3-axis measurements were evaluated. The sensor is able to detect minimal forces of about 1 gf. The sensor was calibrated and results with total forces up to 1450 gf in the normal and tangential directions of the sensor are presented. The test revealed that the sensor is able to measure the different components of the force vector.

  18. Molecular characterisation of lumpy skin disease virus and sheeppox virus based on P32 gene

    Directory of Open Access Journals (Sweden)

    P.M.A.Rashid

    2017-06-01

    Full Text Available Lumpy skin disease virus (LSDV and sheeppox virus (SPV have a considerable economic impact on the cattle and small ruminant industry. They are listed in group A of contagious disease by the World Organization for Animal Health (OIE. This study addressed molecular characterisation of first LSDV outbreak and an endemic SPV in Kurdistan region of Iraq based on P32 gene. The results indicated that P32 gene can be successfully used for diagnosis of LSDV. The phylogenic and molecular analysis showed that there may be a new LSDV isolate circulating in Kurdistan which uniquely shared the same characteristic amino acid sequence with SPV and GPV, leucine at amino acid position 51 in P32 gene as well as few genetically distinct SPV causing pox disease in Kurdistan sheep. This study provided sequence information of P32 gene for several LSDV isolates, which positively affects the epidemiological study of Capripoxvirus

  19. Characterisation and Skin Distribution of Lecithin-Based Coenzyme Q10-Loaded Lipid Nanocapsules

    Science.gov (United States)

    Zhou, Huafeng; Yue, Yang; Liu, Guanlan; Li, Yan; Zhang, Jing; Yan, Zemin; Duan, Mingxing

    2010-10-01

    The purpose of this study was to investigate the influence of the inner lipid ratio on the physicochemical properties and skin targeting of surfactant-free lecithin-based coenzyme Q10-loaded lipid nanocapsules (CoQ10-LNCs). The smaller particle size of CoQ10-LNCs was achieved by high pressure and a lower ratio of CoQ10/GTCC (Caprylic/capric triglyceride); however, the zeta potential of CoQ10-LNCs was above /- 60 mV/ with no distinct difference among them at different ratios of CoQ10/GTCC. Both the crystallisation point and the index decreased with the decreasing ratio of CoQ10/GTCC and smaller particle size; interestingly, the supercooled state of CoQ10-LNCs was observed at particle size below about 200 nm, as verified by differential scanning calorimetry (DSC) in one heating-cooling cycle. The lecithin monolayer sphere structure of CoQ10-LNCs was investigated by cryogenic transmission electron microscopy (Cryo-TEM). The skin penetration results revealed that the distribution of Nile red-loaded CoQ10-LNCs depended on the ratio of inner CoQ10/GTCC; moreover, epidermal targeting and superficial dermal targeting were achieved by the CoQ10-LNCs application. The highest fluorescence response was observed at a ratio of inner CoQ10/GTCC of 1:1. These observations suggest that lecithin-based LNCs could be used as a promising topical delivery vehicle for lipophilic compounds.

  20. Characterisation and Skin Distribution of Lecithin-Based Coenzyme Q10-Loaded Lipid Nanocapsules

    Directory of Open Access Journals (Sweden)

    Yan Zemin

    2010-01-01

    Full Text Available Abstract The purpose of this study was to investigate the influence of the inner lipid ratio on the physicochemical properties and skin targeting of surfactant-free lecithin-based coenzyme Q10-loaded lipid nanocapsules (CoQ10-LNCs. The smaller particle size of CoQ10-LNCs was achieved by high pressure and a lower ratio of CoQ10/GTCC (Caprylic/capric triglyceride; however, the zeta potential of CoQ10-LNCs was above /− 60 mV/ with no distinct difference among them at different ratios of CoQ10/GTCC. Both the crystallisation point and the index decreased with the decreasing ratio of CoQ10/GTCC and smaller particle size; interestingly, the supercooled state of CoQ10-LNCs was observed at particle size below about 200 nm, as verified by differential scanning calorimetry (DSC in one heating–cooling cycle. The lecithin monolayer sphere structure of CoQ10-LNCs was investigated by cryogenic transmission electron microscopy (Cryo-TEM. The skin penetration results revealed that the distribution of Nile red-loaded CoQ10-LNCs depended on the ratio of inner CoQ10/GTCC; moreover, epidermal targeting and superficial dermal targeting were achieved by the CoQ10-LNCs application. The highest fluorescence response was observed at a ratio of inner CoQ10/GTCC of 1:1. These observations suggest that lecithin-based LNCs could be used as a promising topical delivery vehicle for lipophilic compounds.

  1. Sensitivity Analysis Based on Markovian Integration by Parts Formula

    Directory of Open Access Journals (Sweden)

    Yongsheng Hang

    2017-10-01

    Full Text Available Sensitivity analysis is widely applied in financial risk management and engineering; it describes the variations brought by the changes of parameters. Since the integration by parts technique for Markov chains is well developed in recent years, in this paper we apply it for computation of sensitivity and show the closed-form expressions for two commonly-used time-continuous Markovian models. By comparison, we conclude that our approach outperforms the existing technique of computing sensitivity on Markovian models.

  2. UV irradiation-induced methionine oxidation in human skin keratins: Mass spectrometry-based non-invasive proteomic analysis.

    Science.gov (United States)

    Lee, Seon Hwa; Matsushima, Keita; Miyamoto, Kohei; Oe, Tomoyuki

    2016-02-05

    Ultraviolet (UV) radiation is the major environmental factor that causes oxidative skin damage. Keratins are the main constituents of human skin and have been identified as oxidative target proteins. We have recently developed a mass spectrometry (MS)-based non-invasive proteomic methodology to screen oxidative modifications in human skin keratins. Using this methodology, UV effects on methionine (Met) oxidation in human skin keratins were investigated. The initial screening revealed that Met(259), Met(262), and Met(296) in K1 keratin were the most susceptible oxidation sites upon UVA (or UVB) irradiation of human tape-stripped skin. Subsequent liquid chromatography/electrospray ionization-MS and tandem MS analyses confirmed amino acid sequences and oxidation sites of tryptic peptides D(290)VDGAYMTK(298) (P1) and N(258)MQDMVEDYR(267) (P2). The relative oxidation levels of P1 and P2 increased in a time-dependent manner upon UVA irradiation. Butylated hydroxytoluene was the most effective antioxidant for artifactual oxidation of Met residues. The relative oxidation levels of P1 and P2 after UVA irradiation for 48 h corresponded to treatment with 100mM hydrogen peroxide for 15 min. In addition, Met(259) was oxidized by only UVA irradiation. The Met sites identified in conjunction with the current proteomic methodology can be used to evaluate skin damage under various conditions of oxidative stress. We demonstrated that the relative Met oxidation levels in keratins directly reflected UV-induced damages to human tape-stripped skin. Human skin proteins isolated by tape stripping were analyzed by MS-based non-invasive proteomic methodology. Met(259), Met(262), and Met(296) in K1 keratin were the most susceptible oxidation sites upon UV irradiation. Met(259) was oxidized by only UVA irradiation. Quantitative LC/ESI-SRM/MS analyses confirmed a time-dependent increase in the relative oxidation of target peptides (P1 and P2) containing these Met residues, upon UVA irradiation

  3. Formulation and Evaluation of Exotic Fat Based Cosmeceuticals for Skin Repair

    OpenAIRE

    Mandawgade, S. D.; Patravale, Vandana B.

    2008-01-01

    Mango butter was explored as a functional, natural supplement and active skin ingredient in skin care formulations. A foot care cream was developed with mango butter to evaluate its medicinal value and protective function in skin repair. Qualitative comparison and clinical case studies of the product were carried out. Wound healing potential of foot care cream was investigated on the rat excision and incision wound models. Results of the clinical studies demonstrated complete repair of worn a...

  4. Novel approach for classifying chemicals according to skin sensitizing potency by non-radioisotopic modification of the local lymph node assay.

    Science.gov (United States)

    Takeyoshi, Masahiro; Iida, Kenji; Shiraishi, Keiji; Hoshuyama, Satsuki

    2005-01-01

    The murine local lymph node assay (LLNA) is currently recognized as a stand-alone sensitization test for determining the sensitizing potential of chemicals, and it has the advantage of yielding a quantitative endpoint that can be used to predict the sensitization potency of chemicals. The EC3 has been proposed as a parameter for classifying chemicals according to the sensitization potency. We previously developed a non-radioisotopic endpoint for the LLNA based on 5-bromo-2'-deoxyuridine (BrdU) incorporation (non-RI LLNA), and we are proposing a new procedure to predict the sensitization potency of chemicals based on comparisons with known human contact allergens. Nine chemicals (i.e. diphencyclopropenone, p-phenylenediamine, glutaraldehyde, cinnamicaldehyde, citral, eugenol, isopropyl myristate, propyleneglycol and hexane) categorized as human contact allergen classes 1-5 were tested by the non-RI LLNA with the following reference allergens: 2,4-dinitrochlorobenzene (DNCB) as a class 1 human contact allergen, isoeugenol as a class 2 human contact allergen and alpha-hexylcinnamic aldehyde (HCA) as a class 3 human contact allergen. Consequently, nine test chemicals were almost assigned to their correct allergen class. The results suggested that the new procedure for non-RI LLNA can provide correct sensitization potency data. Sensitization potency data are useful for evaluating the sensitization risk to humans of exposure to new chemical products. Accordingly, this approach would be an effective modification of LLNA with regard to its experimental design. Moreover, this procedure can be applied also to the standard LLNA with radioisotopes and to other modifications of the LLNA. Copyright 2005 John Wiley & Sons, Ltd.

  5. Guideline values for skin decontamination measures based on nuclidspecific dose equivalent rate factors

    International Nuclear Information System (INIS)

    Pfob, H.; Heinemann, G.

    1992-01-01

    Corresponding dose equivalent rate factors for various radionuclides are now available for determining the skin dose caused by skin contamination. These dose equivalent rate factors take into account all contributions from the types of radiation emitted. Any limits for skin decontamination measures are nowhere contained or determined yet. However, radiological protection does in practice require at least guideline values in order to prevent unsuitable or detrimental measures that can be noticed quite often. New calculations of dose equivalent rate factors for the skin now make the recommendation of guideline values possible. (author)

  6. Few Associations Found between Mold and Other Allergen Concentrations in the Home versus Skin Sensitivity from Children with Asthma after Hurricane Katrina in the Head-Off Environmental Asthma in Louisiana Study

    Directory of Open Access Journals (Sweden)

    L. F. Grimsley

    2012-01-01

    Full Text Available Mold and other allergen exposures exacerbate asthma symptoms in sensitized individuals. We evaluated allergen concentrations, skin test sensitivities, and asthma morbidity for 182 children, aged 4–12 years, with moderate to severe asthma, enrolled 18 months after Katrina, from the city of New Orleans and the surrounding parishes that were impacted by the storm, into the Head-off Environmental Asthma in Louisiana (HEAL observational study. Dust (indoor and air (indoor and outdoor samples were collected at baseline of 6 and 12 months. Dust samples were evaluated for dust mite, cockroach, mouse, and Alternaria by immunoassay. Air samples were evaluated for airborne mold spore concentrations. Overall, 89% of the children tested positive to ≥1 indoor allergen, with allergen-specific sensitivities ranging from 18% to 67%. Allergen concentration was associated with skin sensitivity for 1 of 10 environmental triggers analyzed (cat. Asthma symptom days did not differ with skin test sensitivity, and surprisingly, increased symptoms were observed in children whose baseline indoor airborne mold concentrations were below median levels. This association was not observed in follow-up assessments. The lack of relationship among allergen levels (including mold, sensitivities, and asthma symptoms points to the complexity of attempting to assess these associations during rapidly changing social and environmental conditions.

  7. Sensitivity kernels for viscoelastic loading based on adjoint methods

    Science.gov (United States)

    Al-Attar, David; Tromp, Jeroen

    2014-01-01

    Observations of glacial isostatic adjustment (GIA) allow for inferences to be made about mantle viscosity, ice sheet history and other related parameters. Typically, this inverse problem can be formulated as minimizing the misfit between the given observations and a corresponding set of synthetic data. When the number of parameters is large, solution of such optimization problems can be computationally challenging. A practical, albeit non-ideal, solution is to use gradient-based optimization. Although the gradient of the misfit required in such methods could be calculated approximately using finite differences, the necessary computation time grows linearly with the number of model parameters, and so this is often infeasible. A far better approach is to apply the `adjoint method', which allows the exact gradient to be calculated from a single solution of the forward problem, along with one solution of the associated adjoint problem. As a first step towards applying the adjoint method to the GIA inverse problem, we consider its application to a simpler viscoelastic loading problem in which gravitationally self-consistent ocean loading is neglected. The earth model considered is non-rotating, self-gravitating, compressible, hydrostatically pre-stressed, laterally heterogeneous and possesses a Maxwell solid rheology. We determine adjoint equations and Fréchet kernels for this problem based on a Lagrange multiplier method. Given an objective functional J defined in terms of the surface deformation fields, we show that its first-order perturbation can be written δ J = int _{MS}K_{η }δ ln η dV +int _{t0}^{t1}int _{partial M}K_{dot{σ }} δ dot{σ } dS dt, where δ ln η = δη/η denotes relative viscosity variations in solid regions MS, dV is the volume element, δ dot{σ } is the perturbation to the time derivative of the surface load which is defined on the earth model's surface ∂M and for times [t0, t1] and dS is the surface element on ∂M. The `viscosity

  8. Highly sensitive DNA sensors based on cerium oxide nanorods

    Science.gov (United States)

    Nguyet, Nguyen Thi; Hai Yen, Le Thi; Van Thu, Vu; lan, Hoang; Trung, Tran; Vuong, Pham Hung; Tam, Phuong Dinh

    2018-04-01

    In this work, a CeO2 nanorod (NR)-based electrochemical DNA sensor was developed to identify Salmonella that causes food-borne infections. CeO2 NRs were synthesized without templates via a simple and unexpensive hydrothermal approach at 170 °C for 12 h by using CeO(NO3)3·6H2O as a Ce source. The DNA probe was immobilized onto the CeO2 NR-modified electrode through covalent attachment. The characteristics of the hybridized DNA were analyzed through electrochemical impedance spectroscopy (EIS) with [Fe(CN)6]3-/4- as a redox probe. Experimental results showed that electron transfer resistance (Ret) increased after the DNA probe was attached to the electrode surface and increased further after the DNA probe hybridized with its complementary sequence. A linear response of Ret to the target DNA concentration was found from 0.01 μM to 2 μM. The detection limit and sensitivity of the DNA sensor were 0.01 μM and 3362.1 Ω μM-1 cm-2, respectively. Various parameters, such as pH value, ionic strength, DNA probe concentration, and hybridization time, influencing DNA sensor responses were also investigated.

  9. Tuning pentacene based dye-sensitized solar cells.

    Science.gov (United States)

    Kunzmann, Andreas; Gruber, Marco; Casillas, Rubén; Tykwinski, Rik R; Costa, Rubén D; Guldi, Dirk M

    2018-05-10

    We report on the synthesis, as well as photophysical and electrochemical characterization of a new family of pentacene derivatives, which are applied in n-type dye-sensitized solar cells (DSSCs). As far as the molecular structure of the pentacene is concerned, the synthetic design focuses on cyano acrylic tethered at the 13-position of the pentacene chromophore. The electrolyte composition features increasing amounts of Li+ ions as an additive. In general, the increase of Li+ concentrations extrinsically reduces the quasi Fermi level of the photoanode and as such facilitates the electron injection process. We demonstrate that pentacene derivatives give rise to a unique charge injection process, which is controlled by the positioning of the quasi Fermi level energies as a function of the Li+ concentration. As a result of the enhanced charge injection, device efficiencies as high as 1.5% are achieved, representing a 3-fold increase from previously reported efficiencies in pentacene-based DSSCs. These findings are supported by device analysis in combination with transient absorption and electrochemical impedance spectroscopy assays.

  10. Method of characteristics - Based sensitivity calculations for international PWR benchmark

    International Nuclear Information System (INIS)

    Suslov, I. R.; Tormyshev, I. V.; Komlev, O. G.

    2013-01-01

    Method to calculate sensitivity of fractional-linear neutron flux functionals to transport equation coefficients is proposed. Implementation of the method on the basis of MOC code MCCG3D is developed. Sensitivity calculations for fission intensity for international PWR benchmark are performed. (authors)

  11. A sensitive nonenzymatic hydrogen peroxide sensor based on ...

    Indian Academy of Sciences (India)

    ple, H2O2 is useful for food production, sterilization, clin- ical applications and environmental analyses.1–4 Further, ... and showed a fast response and high sensitivity.9. Gu et al10 have synthesized Cu–. Ni(OH)2 nanocomposites and applied it as the fast and sensitive H2O2 sensor material. Ag nanoparticles were. ∗.

  12. Oromandibular reconstruction with chimeric double-skin paddle flap based on peroneal vessel axis for synchronous opposite double oral cancer.

    Science.gov (United States)

    Huang, Shih-Tsai; Liu, Wen-Chung; Chen, Lee-Wei; Yang, Kuo-Chung

    2015-05-01

    Synchronous double oral cancer represents the minority of cases of head and neck cancer. After tumor ablation, 2 separate oromandibular defects, even combined with a through-and-through oral defect, pose a serious reconstructive challenge. The ideal method for reconstruction remains controversial. Based on the peroneal vessel axis, a chimeric double-skin paddle peroneal fasciocutaneous or fibular osteomyocutaneous flap could be designed to accomplish the difficult reconstruction. Six male patients, each with 2 separate oromandibular defects after tumor ablation of synchronous double oral cancer, received double-skin paddle flap reconstruction with 3 peroneal fasciocutaneous and 3 fibular osteomyocutaneous flaps. All 6 flaps survived; however, complications included 1 skin paddle lost due to insufficient perfusion of a visible perforator, and 1 superficial necrosis occurring over the tip of a longer skin paddle. One postoperative intraoral infection and 1 donor site infection were also reported. During follow-up, 3 months later, 1 patient succumbed to local recurrence and bony metastasis. One patient developed a new cancer in the maxillary gingiva, and another had osteoradionecrosis 8 months later. Four patients gained acceptable cosmesis with good oral competence. A chimeric flap based on the peroneal artery could provide a segment of fibular bone, 1 or 2 skin paddles, and a cuff of the flexor hallucis longus muscle simultaneously. For 1-stage reconstruction of separate oromandibular defects after tumor ablation of synchronous double oral cancer, this design could provide all components at 1 transfer.

  13. Does lactobionic acid affect the colloidal structure and skin moisturizing potential of the alkyl polyglucoside-based emulsion systems?

    Science.gov (United States)

    Tasic-Kostov, M Z; Reichl, S; Lukic, M Z; Jaksic, I N; Savic, S D

    2011-11-01

    Moisturizing creams are the most prescribed products in dermatology, essential in maintaining healthy skin as well as in the topical treatment of some diseases. The irritation potential of commonly used emulsifiers and moisturizing ingredients, but also their mutual interactions, could affect the functionality and safety of those dermopharmaceutics. The aim of this study was to promote moisturizing alkyl polyglucoside (APG)-based emulsion as vehicle for lactobionic acid (LA), advantageous representative of the alphahydroxyacids (AHAs)-multifunctional moisturizers, assessing the safety for use (in vitro acute skin irritation test using cytotoxicity assay compared with in vivo data obtained using skin bioengineering methods) and in vivo moisturizing capacity (bioengineering of the skin). In order to investigate possible interactions between APG mild natural emulsifier-based emulsion and LA, a deeper insight into the colloidal structure of the placebo and the emulsion with LA was given using polarization and transmission electron microscopy, rheology, thermal and texture analysis. This study showed that APG-based emulsions could be promoted as safe cosmetic/dermopharmaceutical vehicles and carriers for extremely acidic and hygroscopic AHA class of actives (specifically LA); prospective safety for human use of both APG and LA with the correlation between in vivo and in vitro findings was shown. However, it was revealed that LA strongly influenced the colloidal structure of the emulsion based on APGs and promoted the formation of lamellar structures which reflects onto the mode of water distribution within the cream. The advantageous skin hydrating potential of LA-containing emulsion vs. placebo was unlikely to be achieved, pointing that emulsions stabilized by lamellar liquid crystalline structures probably are not satisfying carriers for highly hygroscopic actives in order to reach the full moisturizing potential. Safe and effective use on dry skin is presumed.

  14. Peristomal Skin Complications Are Common, Expensive, and Difficult to Manage: A Population Based Cost Modeling Study

    Science.gov (United States)

    Meisner, Søren; Lehur, Paul-Antoine; Moran, Brendan; Martins, Lina; Jemec, Gregor Borut Ernst

    2012-01-01

    Background Peristomal skin complications (PSCs) are the most common post-operative complications following creation of a stoma. Living with a stoma is a challenge, not only for the patient and their carers, but also for society as a whole. Due to methodological problems of PSC assessment, the associated health-economic burden of medium to longterm complications has been poorly described. Aim The aim of the present study was to create a model to estimate treatment costs of PSCs using the standardized assessment Ostomy Skin Tool as a reference. The resultant model was applied to a real-life global data set of stoma patients (n = 3017) to determine the prevalence and financial burden of PSCs. Methods Eleven experienced stoma care nurses were interviewed to get a global understanding of a treatment algorithm that formed the basis of the cost analysis. The estimated costs were based on a seven week treatment period. PSC costs were estimated for five underlying diagnostic categories and three levels of severity. The estimated treatment costs of severe cases of PSCs were increased 2–5 fold for the different diagnostic categories of PSCs compared with mild cases. French unit costs were applied to the global data set. Results The estimated total average cost for a seven week treatment period (including appliances and accessories) was 263€ for those with PSCs (n = 1742) compared to 215€ for those without PSCs (n = 1172). A co-variance analysis showed that leakage level had a significant impact on PSC cost from ‘rarely/never’ to ‘always/often’ p<0.00001 and from ‘rarely/never’ to ‘sometimes’ p = 0.0115. Conclusion PSCs are common and troublesome and the consequences are substantial, both for the patient and from a health economic viewpoint. PSCs should be diagnosed and treated at an early stage to prevent long term, debilitating and expensive complications. PMID:22679479

  15. Peristomal skin complications are common, expensive, and difficult to manage: a population based cost modeling study.

    Directory of Open Access Journals (Sweden)

    Søren Meisner

    Full Text Available BACKGROUND: Peristomal skin complications (PSCs are the most common post-operative complications following creation of a stoma. Living with a stoma is a challenge, not only for the patient and their carers, but also for society as a whole. Due to methodological problems of PSC assessment, the associated health-economic burden of medium to longterm complications has been poorly described. AIM: The aim of the present study was to create a model to estimate treatment costs of PSCs using the standardized assessment Ostomy Skin Tool as a reference. The resultant model was applied to a real-life global data set of stoma patients (n = 3017 to determine the prevalence and financial burden of PSCs. METHODS: Eleven experienced stoma care nurses were interviewed to get a global understanding of a treatment algorithm that formed the basis of the cost analysis. The estimated costs were based on a seven week treatment period. PSC costs were estimated for five underlying diagnostic categories and three levels of severity. The estimated treatment costs of severe cases of PSCs were increased 2-5 fold for the different diagnostic categories of PSCs compared with mild cases. French unit costs were applied to the global data set. RESULTS: The estimated total average cost for a seven week treatment period (including appliances and accessories was 263€ for those with PSCs (n = 1742 compared to 215€ for those without PSCs (n = 1172. A co-variance analysis showed that leakage level had a significant impact on PSC cost from 'rarely/never' to 'always/often' p<0.00001 and from 'rarely/never' to 'sometimes' p = 0.0115. CONCLUSION: PSCs are common and troublesome and the consequences are substantial, both for the patient and from a health economic viewpoint. PSCs should be diagnosed and treated at an early stage to prevent long term, debilitating and expensive complications.

  16. Mesenchymal stem cells delivered in a microsphere-based engineered skin contribute to cutaneous wound healing and sweat gland repair.

    Science.gov (United States)

    Huang, Sha; Lu, Gang; Wu, Yan; Jirigala, Enhe; Xu, Yongan; Ma, Kui; Fu, Xiaobing

    2012-04-01

    Bone-marrow-derived mesenchymal stem cells (BM-MSCs) can contribute to wound healing after skin injury. However, the role of BM-MSCs on repairing skin appendages in renewal tissues is incompletely explored. Moreover, most preclinical studies suggest that the therapeutic effects afforded by BM-MSCs transplantation are short-lived and relatively unstable. To assess whether engrafted bone-marrow-derived mesenchymal stem cells via a delivery system can participate in cutaneous wound healing and sweat-gland repair in mice. For safe and effective delivery of BM-MSCs to wounds, epidermal growth factor (EGF) microspheres were firstly developed to both support cells and maintain appropriate stimuli, then cell-seeded microspheres were incorporated with biomimetic scaffolds and thus fabricated an engineered skin construct with epithelial differentiation and proliferative potential. The applied efficacy was examined by implanting them into excisional wounds on both back and paws of hind legs in mice. After 3 weeks, BM-MSC-engineered skin (EGF loaded) treated wounds exhibited accelerated healing with increased re-epithelialization rates and less skin contraction. Furthermore, histological and immunofluorescence staining analysis revealed sweat glands-like structures became more apparent in BM-MSC-engineered skin (EGF loaded) treated wounds but the number of implanted BM-MSCs were decreased gradually in later phases of healing progression. Our study suggests that BM-MSCs delivered by this EGF microspheres-based engineered skin model may be a promising strategy to repair sweat glands and improve cutaneous wound healing after injury and success in this study might provide a potential benefit for BM-MSCs administration clinically. Copyright © 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  17. Image-based non-contact monitoring of skin texture changed by piloerection for emotion estimation

    Science.gov (United States)

    Uchida, Mihiro; Akaho, Rina; Ogawa, Keiko; Tsumura, Norimichi

    2018-02-01

    In this paper, we find the effective feature values of skin textures captured by non-contact camera to monitor piloerection on the skin for emotion estimation. Recently, emotion estimation is required for service robots to interact with human more naturally. There are a lot of researches of estimating emotion and additional methods are required to improve emotion estimation because using only a few methods may not give enough information for emotion estimation. In the previous study, it is necessary to fix a device on the subject's arm for detecting piloerection, but the contact monitoring can be stress itself and distract the subject from concentrating in the stimuli and evoking strong emotion. So, we focused on the piloerection as the object obtained with non-contact methods. The piloerection is observed as goose bumps on the skin when the subject is emotionally moved, scared and so on. This phenomenon is caused by contraction of arrector pili muscles with the activation of sympathetic nervous system. This piloerection changes skin texture. Skin texture is important in the cosmetic industry to evaluate skin condition. Therefore, we thought that it will be effective to evaluate the condition of skin texture for emotion estimation. The evaluations were performed by extracting the effective feature values from skin textures captured with a high resolution camera. The effective feature values should have high correlation with the degree of piloerection. In this paper, we found that standard deviation of short-line inclination angles in the texture is well correlated with the degree of piloerection.

  18. Collagen/chitosan based two-compartment and bi-functional dermal scaffolds for skin regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feng [Department of Plastic Surgery and Burns, Shenzhen Second People' s Hospital, Shenzhen 518035 (China); Wang, Mingbo [Key Laboratory of Biomedical Materials and Implants, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); She, Zhending [Key Laboratory of Biomedical Materials and Implants, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Shenzhen Lando Biomaterials Co., Ltd., Shenzhen 518057 (China); Fan, Kunwu; Xu, Cheng [Department of Plastic Surgery and Burns, Shenzhen Second People' s Hospital, Shenzhen 518035 (China); Chu, Bin; Chen, Changsheng [Key Laboratory of Biomedical Materials and Implants, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Shi, Shengjun, E-mail: shengjunshi@yahoo.com [The Burns Department of Zhujiang Hospital, Southern Medical University, Guangzhou 510280 (China); Tan, Rongwei, E-mail: tanrw@landobiom.com [Key Laboratory of Biomedical Materials and Implants, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Shenzhen Lando Biomaterials Co., Ltd., Shenzhen 518057 (China)

    2015-07-01

    Inspired from the sophisticated bilayer structures of natural dermis, here, we reported collagen/chitosan based two-compartment and bi-functional dermal scaffolds. Two functions refer to mediating rapid angiogenesis based on recombinant human vascular endothelial growth factor (rhVEGF) and antibacterial from gentamicin, which were encapsulated in PLGA microspheres. The gentamicin and rhVEGF encapsulated PLGA microspheres were further combined with collagen/chitosan mixtures in low (lower layer) and high (upper layer) concentrations, and molded to generate the two-compartment and bi-functional scaffolds. Based on morphology and pore structure analyses, it was found that the scaffold has a distinct double layered porous and connective structure with PLGA microspheres encapsulated. Statistical analysis indicated that the pores in the upper layer and in the lower layer have great variations in diameter, indicative of a two-compartment structure. The release profiles of gentamicin and rhVEGF exceeded 28 and 49 days, respectively. In vitro culture of mouse fibroblasts showed that the scaffold can facilitate cell adhesion and proliferation. Moreover, the scaffold can obviously inhibit proliferation of Staphylococcus aureus and Serratia marcescens, exhibiting its unique antibacterial effect. The two-compartment and bi-functional dermal scaffolds can be a promising candidate for skin regeneration. - Highlights: • The dermal scaffold is inspired from the bilayer structures of natural dermis. • The dermal scaffold has two-compartment structures. • The dermal scaffold containing VEGF and gentamicin encapsulated PLGA microspheres • The dermal scaffold can facilitate cell adhesion and proliferation.

  19. Collagen/chitosan based two-compartment and bi-functional dermal scaffolds for skin regeneration

    International Nuclear Information System (INIS)

    Wang, Feng; Wang, Mingbo; She, Zhending; Fan, Kunwu; Xu, Cheng; Chu, Bin; Chen, Changsheng; Shi, Shengjun; Tan, Rongwei

    2015-01-01

    Inspired from the sophisticated bilayer structures of natural dermis, here, we reported collagen/chitosan based two-compartment and bi-functional dermal scaffolds. Two functions refer to mediating rapid angiogenesis based on recombinant human vascular endothelial growth factor (rhVEGF) and antibacterial from gentamicin, which were encapsulated in PLGA microspheres. The gentamicin and rhVEGF encapsulated PLGA microspheres were further combined with collagen/chitosan mixtures in low (lower layer) and high (upper layer) concentrations, and molded to generate the two-compartment and bi-functional scaffolds. Based on morphology and pore structure analyses, it was found that the scaffold has a distinct double layered porous and connective structure with PLGA microspheres encapsulated. Statistical analysis indicated that the pores in the upper layer and in the lower layer have great variations in diameter, indicative of a two-compartment structure. The release profiles of gentamicin and rhVEGF exceeded 28 and 49 days, respectively. In vitro culture of mouse fibroblasts showed that the scaffold can facilitate cell adhesion and proliferation. Moreover, the scaffold can obviously inhibit proliferation of Staphylococcus aureus and Serratia marcescens, exhibiting its unique antibacterial effect. The two-compartment and bi-functional dermal scaffolds can be a promising candidate for skin regeneration. - Highlights: • The dermal scaffold is inspired from the bilayer structures of natural dermis. • The dermal scaffold has two-compartment structures. • The dermal scaffold containing VEGF and gentamicin encapsulated PLGA microspheres • The dermal scaffold can facilitate cell adhesion and proliferation

  20. Quantitative Sasang Constitution Diagnosis Method for Distinguishing between Tae-eumin and Soeumin Types Based on Elasticity Measurements of the Skin of the Human Hand

    OpenAIRE

    Song, Han Wook; Lee, SungJun; Park, Yon Kyu; Woo, Sam Yong

    2009-01-01

    The usefulness of constitutional diagnoses based on skin measurements has been established in oriental medicine. However, it is very difficult to standardize traditional diagnosis methods. According to Sasang constitutional medicine, humans can be distinguished based on properties of the skin, including its texture, roughness, hardness and elasticity. The elasticity of the skin was previously used to distinguish between people with Tae-eumin (TE) and Soeumin (SE) constitutions. The present st...

  1. Long period grating based refractometer with polarization-sensitive interrogation

    International Nuclear Information System (INIS)

    Eftimov, T; Bock, W; Mikulic, P; Nikolova, K

    2010-01-01

    We propose a new scheme for the interrogation of long-period fiber gratings (LPGs) which makes use of their polarization properties. Polarization-sensitive interrogation was applied to detect changes due to changes of the external refractive index by using three wavelengths on the International Telecommunication Union (ITU) grid. We show that the new approach can allow for a greater sensitivity and can be used in combination with spectral multiplexing schemes

  2. Sensitive Data Protection Based on Intrusion Tolerance in Cloud Computing

    OpenAIRE

    Jingyu Wang; xuefeng Zheng; Dengliang Luo

    2011-01-01

    Service integration and supply on-demand coming from cloud computing can significantly improve the utilization of computing resources and reduce power consumption of per service, and effectively avoid the error of computing resources. However, cloud computing is still facing the problem of intrusion tolerance of the cloud computing platform and sensitive data of new enterprise data center. In order to address the problem of intrusion tolerance of cloud computing platform and sensitive data in...

  3. Skin carotenoids as biomarker for vegetable and fruit intake: Validation of the reflection-spectroscopy based “Veggie Meter”

    Science.gov (United States)

    Skin is a relatively stable storage medium for carotenoids; non-invasive optical measurements of carotenoids in this tissue via Resonance Raman spectroscopy (RRS) serve as a non-invasive biomarker for fruit and vegetable (F/V) intake. The RRS method has been validated with HPLC-based measurements of...

  4. Self-powered gustation electronic skin for mimicking taste buds based on piezoelectric-enzymatic reaction coupling process

    Science.gov (United States)

    Zhao, Tianming; Fu, Yongming; He, Haoxuan; Dong, Chuanyi; Zhang, Linlin; Zeng, Hui; Xing, Lili; Xue, Xinyu

    2018-02-01

    A new self-powered wearable gustation electronic skin for mimicking taste buds has been realized based on enzyme-modified/ZnO nanowire arrays on patterned-electrode flexible substrate. The e-skin can actively taste beverages or fruits without any external electric power. Through the piezoelectric-enzymatic reaction coupling effect, the nanowires can harvest the mechanical energy of body movement and output piezoelectric signal. The piezoelectric output is significantly dependent on the concentration of target analyte. The response for detecting 2 × 10-2 M ascorbic acid (ascorbate acid oxidase@ZnO) is up to 171.747, and the selectivity is high. The response for detecting 50% alcohol (alcohol oxidase@ZnO) is up to 45.867. Our results provide a new research direction for the development of multifunctional e-skin and expand the study scope for self-powered bionic systems.

  5. Carbon Nanofiber versus Graphene-Based Stretchable Capacitive Touch Sensors for Artificial Electronic Skin.

    Science.gov (United States)

    Cataldi, Pietro; Dussoni, Simeone; Ceseracciu, Luca; Maggiali, Marco; Natale, Lorenzo; Metta, Giorgio; Athanassiou, Athanassia; Bayer, Ilker S

    2018-02-01

    Stretchable capacitive devices are instrumental for new-generation multifunctional haptic technologies particularly suited for soft robotics and electronic skin applications. A majority of elongating soft electronics still rely on silicone for building devices or sensors by multiple-step replication. In this study, fabrication of a reliable elongating parallel-plate capacitive touch sensor, using nitrile rubber gloves as templates, is demonstrated. Spray coating both sides of a rubber piece cut out of a glove with a conductive polymer suspension carrying dispersed carbon nanofibers (CnFs) or graphene nanoplatelets (GnPs) is sufficient for making electrodes with low sheet resistance values (≈10 Ω sq -1 ). The electrodes based on CnFs maintain their conductivity up to 100% elongation whereas the GnPs-based ones form cracks before 60% elongation. However, both electrodes are reliable under elongation levels associated with human joints motility (≈20%). Strikingly, structural damages due to repeated elongation/recovery cycles could be healed through annealing. Haptic sensing characteristics of a stretchable capacitive device by wrapping it around the fingertip of a robotic hand (ICub) are demonstrated. Tactile forces as low as 0.03 N and as high as 5 N can be easily sensed by the device under elongation or over curvilinear surfaces.

  6. Mastectomy Skin Necrosis After Breast Reconstruction: A Comparative Analysis Between Autologous Reconstruction and Implant-Based Reconstruction.

    Science.gov (United States)

    Sue, Gloria R; Lee, Gordon K

    2018-05-01

    Mastectomy skin necrosis is a significant problem after breast reconstruction. We sought to perform a comparative analysis on this complication between patients undergoing autologous breast reconstruction and patients undergoing 2-stage expander implant breast reconstruction. A retrospective review was performed on consecutive patients undergoing autologous breast reconstruction or 2-stage expander implant breast reconstruction by the senior author from 2006 through 2015. Patient demographic factors including age, body mass index, history of diabetes, history of smoking, and history of radiation to the breast were collected. Our primary outcome measure was mastectomy skin necrosis. Fisher exact test was used for statistical analysis between the 2 patient cohorts. The treatment patterns of mastectomy skin necrosis were then analyzed. We identified 204 patients who underwent autologous breast reconstruction and 293 patients who underwent 2-stage expander implant breast reconstruction. Patients undergoing autologous breast reconstruction were older, heavier, more likely to have diabetes, and more likely to have had prior radiation to the breast compared with patients undergoing implant-based reconstruction. The incidence of mastectomy skin necrosis was 30.4% of patients in the autologous group compared with only 10.6% of patients in the tissue expander group (P care in the autologous group, only 3.2% were treated with local wound care in the tissue expander group (P skin necrosis is significantly more likely to occur after autologous breast reconstruction compared with 2-stage expander implant-based breast reconstruction. Patients with autologous reconstructions are more readily treated with local wound care compared with patients with tissue expanders, who tended to require operative treatment of this complication. Patients considering breast reconstruction should be counseled appropriately regarding the differences in incidence and management of mastectomy skin

  7. Skin Conditions

    Science.gov (United States)

    Your skin is your body's largest organ. It covers and protects your body. Your skin Holds body fluids in, preventing dehydration Keeps harmful ... it Anything that irritates, clogs, or inflames your skin can cause symptoms such as redness, swelling, burning, ...

  8. Topical Curcumin-Based Cream Is Equivalent to Dietary Curcumin in a Skin Cancer Model

    International Nuclear Information System (INIS)

    Sonavane, K.; Phillips, J.; Lakshmaiah, R. R.; Ekshyyan, O.; Moore-Medlin, T.; Rong, X.; Nathan, C. O.; Ekshyyan, O.; Moore-Medlin, T.; Rong, X.; Nathan, C.O.; Gill, J. R.; Clifford, J. L.; Abreo, F.; Boudreaux, D.; Nathan, C. O.

    2012-01-01

    Skin squamous cell carcinoma (SCC), the most common cancer in the USA, is a growing problem with the use of tanning booths causing sun-damaged skin. Antiproliferative effects of curcumin were demonstrated in an aggressive skin cancer cell line SRB12-p9 (ρ< 0.05 compared to control). Topical formulation was as effective as oral curcumin at suppressing tumor growth in a mouse skin cancer model. Curcumin at 15 mg administered by oral, topical, or combined formulation significantly reduced tumor growth compared to control (ρ=0.004). Inhibition of pAKT, pS6, p-4EBP1, pSTAT3, and pERK 1/2 was noted in SRB12-p9 cells post-curcumin treatment compared to control (ρ<0.05). Inhibition of pSTAT3 and pERK 1/2 was also noted in curcumin-treated groups in vivo. IHC analysis revealed human tumor specimens that expressed significantly more activated pERK ( ρ=0.006) and pS6 (ρ< 0.0001) than normal skin samples. This is the first study to compare topical curcumin to oral curcumin. Our data supports the use of curcumin as a chemo preventive for skin SCC where condemned skin is a significant problem. Prevention strategies offer the best hope of future health care costs in a disease that is increasing in incidence due to increased sun exposure.

  9. Self reported skin morbidity and ethnicity: a population-based study in a Western community

    Directory of Open Access Journals (Sweden)

    Kumar Bernadette

    2007-06-01

    Full Text Available Abstract Background Recent studies have shown ethnic differences concerning cardio-vascular disease, diabetes and mental health. Little is known about ethnic differences in skin morbidity. The purpose of this study was to describe possible ethnic differences in self-reported skin morbidity in a Western urban community. Methods The design was cross sectional. 40 888 adults in Oslo, Norway, received a postal questionnaire providing information on socio-demographic factors and self-reported health, including items on skin complaints. Results 18770 individuals answered the questionnaire. In the sample 84% were from Norway. The largest immigrant group was from Western countries (5% and the Indian Subcontinent (3%. Itch was the most prevalent reported skin symptom (7%, and was significantly more reported by men from East Asia (18% and Middle East/North Africa (13%. The same observations were seen for reported dry and sore skin. Hair loss was a dominating complaint for men from the Indian Subcontinent and the Middle East/North Africa (23% and 25% and for women from the same ethnic groups. Women from Sub-Saharan Africa reported significantly more pimples than in the other groups (17%. Conclusion The study showed that there were significant differences in self-reported skin complaints among ethnic groups. Issues concerning the cultural value of some skin symptoms should be examined further.

  10. An ICA-based method for the segmentation of pigmented skin lesions in macroscopic images.

    Science.gov (United States)

    Cavalcanti, Pablo G; Scharcanski, Jacob; Di Persia, Leandro E; Milone, Diego H

    2011-01-01

    Segmentation is an important step in computer-aided diagnostic systems for pigmented skin lesions, since that a good definition of the lesion area and its boundary at the image is very important to distinguish benign from malignant cases. In this paper a new skin lesion segmentation method is proposed. This method uses Independent Component Analysis to locate skin lesions in the image, and this location information is further refined by a Level-set segmentation method. Our method was evaluated in 141 images and achieved an average segmentation error of 16.55%, lower than the results for comparable state-of-the-art methods proposed in literature.

  11. A Flexible Temperature Sensor Based on Reduced Graphene Oxide for Robot Skin Used in Internet of Things.

    Science.gov (United States)

    Liu, Guanyu; Tan, Qiulin; Kou, Hairong; Zhang, Lei; Wang, Jinqi; Lv, Wen; Dong, Helei; Xiong, Jijun

    2018-05-02

    Flexible electronics, which can be distributed on any surface we need, are highly demanded in the development of Internet of Things (IoT), robot technology and electronic skins. Temperature is a fundamental physical parameter, and it is an important indicator in many applications. Therefore, a flexible temperature sensor is required. Here, we report a simple method to fabricate three lightweight, low-cost and flexible temperature sensors, whose sensitive materials are reduced graphene oxide (r-GO), single-walled carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes (MWCNTs). By comparing linearity, sensitive and repeatability, we found that the r-GO temperature sensor had the most balanced performance. Furthermore, the r-GO temperature sensor showed good mechanical properties and it could be bent in different angles with negligible resistance change. In addition, the performance of the r-GO temperature sensor remained stable under different kinds of pressure and was unaffected by surrounding environments, like humidity or other gases, because of the insulating layer on its sensitive layer. The easy-fabricated process and economy, together with the remarkable performance of the r-GO temperature sensor, suggest that it is suitable for use as a robot skin or used in the environment of IoT.

  12. A Flexible Temperature Sensor Based on Reduced Graphene Oxide for Robot Skin Used in Internet of Things

    Directory of Open Access Journals (Sweden)

    Guanyu Liu

    2018-05-01

    Full Text Available Flexible electronics, which can be distributed on any surface we need, are highly demanded in the development of Internet of Things (IoT, robot technology and electronic skins. Temperature is a fundamental physical parameter, and it is an important indicator in many applications. Therefore, a flexible temperature sensor is required. Here, we report a simple method to fabricate three lightweight, low-cost and flexible temperature sensors, whose sensitive materials are reduced graphene oxide (r-GO, single-walled carbon nanotubes (SWCNTs and multi-wall carbon nanotubes (MWCNTs. By comparing linearity, sensitive and repeatability, we found that the r-GO temperature sensor had the most balanced performance. Furthermore, the r-GO temperature sensor showed good mechanical properties and it could be bent in different angles with negligible resistance change. In addition, the performance of the r-GO temperature sensor remained stable under different kinds of pressure and was unaffected by surrounding environments, like humidity or other gases, because of the insulating layer on its sensitive layer. The easy-fabricated process and economy, together with the remarkable performance of the r-GO temperature sensor, suggest that it is suitable for use as a robot skin or used in the environment of IoT.

  13. Skin abscess

    Science.gov (United States)

    Abscess - skin; Cutaneous abscess; Subcutaneous abscess; MRSA - abscess; Staph infection - abscess ... Skin abscesses are common and affect people of all ages. They occur when an infection causes pus ...

  14. From Molecular Design to Co-sensitization; High performance indole based photosensitizers for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Babu, Dickson D.; Su, Rui; El-Shafei, Ahmed; Adhikari, Airody Vasudeva

    2016-01-01

    Highlights: • First report on the effect of anchoring groups on co-sensitization performance. • Two novel co-adsorbers have been designed and synthesized. • Barbituric acid has emerged as a good anchoring group for co-sensitizers. • Co-sensitized device displayed an enhanced efficiency of 8.06%. - Abstract: Herein, we report the molecular design and synthesis of two novel organic co-adsorbers DBA-1((Z)-2-cyano-3-(5-(4-(cyclohexa-1,5-dien-3-ynyl(phenyl)amino)phenyl) -1-hexyl-1H-indol-3-yl)acrylic acid) and (DBA-2) 5-((5-(4-(diphenylamino)phenyl)-1-hexyl-1H-indol-3-yl)methylene) pyrimidine-2,4,6(1H,3H,5H)-trione with D-D-A (donor-donor-acceptor) architecture. We have combined the strong electron donating triphenylamine group with indole moiety attached to different acceptors/anchoring groups, as co-adsorbers for dye-sensitized solar cells and we present for the first time, the role of anchoring/acceptor unit on their co-adsorption properties. In this study, cyanoacetic acid and barbituric acid are employed as anchoring groups in the co-sensitizers DBA-1 and DBA-2, respectively_. Their electrochemical and photo-physical properties along with molecular geometries, obtained from Density Functional Theory (DFT) are employed to vindicate the effect of co-sensitizer structures on photovoltaic properties of DSSCs. We have demonstrated that the co-sensitization effect is profoundly dependent upon the anchoring/acceptor unit in the co-adsorber molecule. Devices co-sensitized using DBA-1 and DBA-2 along with HD-2 (Ru-complex of 4, 4'-bis-(1,4-benzodioxan-5-yl-vinyl)-[2,2']bipyridine), displayed higher power conversion efficiencies (PCEs) than the device sensitized using only HD-2. In the present work, ruthenium based sensitizer, HD-2, has been chosen due to its better solar-to-power conversion efficiency and impressively higher photocurrent densities than that of standard N719. Among them, co-adsorber DBA-2, containing barbituric acid as the acceptor/anchoring group

  15. Nonablative Fractional Laser Resurfacing in Skin of Color: Evidence-based Review

    OpenAIRE

    Kaushik, Shivani B.; Alexis, Andrew F.

    2017-01-01

    Background: Nonablative laser resurfacing represents one of the major advances in procedural dermatology over the past decade. However, its use in darker skin types is limited by safety concerns and a relative lack of available data.

  16. Is story-based blended learning a promising avenue for skin and sexual health education? Results from the PAEDIMED project.

    Science.gov (United States)

    Apfelbacher, Christian J; Deimling, Erika; Wulfhorst, Britta; Adler, Frederic; Diepgen, Thomas L; Linder, Dennis; Blenk, Holger; Stosiek, Nikolaus; Reinmann, Gabi

    2010-03-01

    The PAEDIMED study group developed a learning and teaching scenario for school health education in the area of skin and sexual health in Italy, Romania and Germany, combining web-based and traditional learning ("blended learning"). A questionnaire-based needs assessment and context analysis were conducted, based on which an education scenario was designed. Particular emphasis was put on emotional and motivational aspects, using narrative components in the didactic concept. The design process occupied a central role in the project (design-based research). Evaluation was both formative and summative. Continuous feedback was obtained from relevant stakeholders. Following a prototypical implementation, the scenario was evaluated using questionnaires. The results revealed a high level of acceptance of the education scenario as well as an increase in students' knowledge concerning skin and sexual health. Evaluation also suggested that health education is highly influenced by cultural background and habits as well as diverse contextual and personal conditions.

  17. The relationship between CD86/CD54 expression and THP-1 cell viability in an in vitro skin sensitization test--human cell line activation test (h-CLAT).

    Science.gov (United States)

    Sakaguchi, Hitoshi; Ashikaga, Takao; Miyazawa, Masaaki; Kosaka, Nanae; Ito, Yuichi; Yoneyama, Katsurako; Sono, Sakiko; Itagaki, Hiroshi; Toyoda, Hidekazu; Suzuki, Hiroyuki

    2009-04-01

    Recent regulations for cosmetics in Europe prohibit animal testing for evaluating the sensitization potential of chemicals to improve animal welfare. Yet, there is not an acceptable Organization for Economic Co-operation and Development non-animal skin sensitization test method. Several in vitro skin sensitization methods that focus on the activation of Langerhans cells, including human cell lines, are being evaluated as possible alternatives. In our previous study, we optimized our human cell line activation test (h-CLAT) using THP-1 cells (monocytic leukemia cell line) and conducted an inter-laboratory study. We found that measuring CD86/CD54 expression may be useful for predicting skin sensitization. The aim of this study was to confirm the relationship between CD86/CD54 expression and THP-1 cell viability in the h-CLAT. In this study, 21 allergens (e.g., dinitrochlorobenzene, p-phenylenediamine, Ni) and 8 non-allergens (e.g., SLS, lactic acid) were evaluated. For each chemical, more than 10 concentrations that gave a predicted cell viability range of 20-95% were used. The data showed that expression patterns of CD86/CD54 differed depending on chemical. For most allergens, cytotoxicity (65-90% cell viability) was needed for enhancement of CD86/CD54 expression. The criteria of "CD86 > or = 150 or CD54 > or = 200" resulted in an accuracy of 93%, which confirms appropriate cut-off criteria for h-CLAT. Furthermore, a good correlation was observed between EC3 of local lymph node assay and EC150(CD86) or EC200(CD54) of h-CLAT (12 or 16 chemicals, respectively), which would provide a useful estimate of allergic potency. These findings suggest that h-CLAT would be a good robust in vitro skin sensitization test.

  18. [Improvement of rosacea treatment based on the morphological and functional features of the skin].

    Science.gov (United States)

    Tsiskarishvili, N V; Katsitadze, A G; Tsiskarishvili, Ts I

    2013-10-01

    Rosacea - a widespread disease sometimes aleak with severe complications, mainly affecting the skin. Irrational and inadequate treatment leads to chronicity of diseases and psychosocial disadaptation of patients. Lately, a clear upward trend in the number of patients in whom in the process of complex treatment manifestations (with the varying degrees of severity) of impaired barrier function of the skin are observed and they need the protection and restoration of the damaged stratum corneum. In patients with rosacea in order to study the function of the facial skin's horny layer we used the skin analyzer BIA (bioimpedance analysis, which in duration of 6 seconds determines the moisture content, oiliness and the softness of the skin) and significant deviations from the norm (decrease in moisture content, fatness and increased roughness) was revealed. These changes were most clearly pronounced in patients with steroid rosacea. To restore the skin barrier the drug "Episofit A" (Laboratory of Evolutionary Dermatology, France) has been used (1-2 times a day for 6 weeks). Evaluation of treatment efficacy was conducted every 2 weeks by means of a scale from 0 to 5 for parameters of dryness, erythema, peeling and expression of subjective feelings. In accordance with received results, using of Episofit A emulsion, especially on the baсkground of long-term treatment with topical steroids, had a pronounced therapeutic effect. Thus, treatment of patients with consideration of morphological and functional features of facial skin, helps to improve the results traditional therapy, and the drug is highly effective means of the new direction in skin care - corneotherapy aimed to reconstruct and protect damaged stratum corneum.

  19. Influence of palm oil and glycerol on properties of fish skin gelatin-based films.

    Science.gov (United States)

    Nilsuwan, Krisana; Benjakul, Soottawat; Prodpran, Thummanoon

    2016-06-01

    Properties of fish skin gelatin film incorporated with palm oil at 50 and 75 % (w/w) as affected by glycerol at 0-30 % (w/w) were investigated. Increases in water vapour permeability and elongation at break along with decrease in tensile strength were noticed when levels of glycerol were increased (p fish skin gelatin films without drastic alteration of mechanical properties.

  20. Eraser-based eco-friendly fabrication of a skin-like large-area matrix of flexible carbon nanotube strain and pressure sensors.

    Science.gov (United States)

    Sahatiya, Parikshit; Badhulika, Sushmee

    2017-03-03

    This paper reports a new type of electronic, recoverable skin-like pressure and strain sensor, produced on a flexible, biodegradable pencil-eraser substrate and fabricated using a solvent-free, low-cost and energy efficient process. Multi-walled carbon nanotube (MWCNT) film, the strain sensing element, was patterned on pencil eraser with a rolling pin and a pre-compaction mechanical press. This induces high interfacial bonding between the MWCNTs and the eraser substrate, which enables the sensor to achieve recoverability under ambient conditions. The eraser serves as a substrate for strain sensing, as well as acting as a dielectric for capacitive pressure sensing, thereby eliminating the dielectric deposition step, which is crucial in capacitive-based pressure sensors. The strain sensing transduction mechanism is attributed to the tunneling effect, caused by the elastic behavior of the MWCNTs and the strong mechanical interlock between MWCNTs and the eraser substrate, which restricts slippage of MWCNTs on the eraser thereby minimizing hysteresis. The gauge factor of the strain sensor was calculated to be 2.4, which is comparable to and even better than most of the strain and pressure sensors fabricated with more complex designs and architectures. The sensitivity of the capacitive pressure sensor was found to be 0.135 MPa -1 .To demonstrate the applicability of the sensor as artificial electronic skin, the sensor was assembled on various parts of the human body and corresponding movements and touch sensation were monitored. The entire fabrication process is scalable and can be integrated into large areas to map spatial pressure distributions. This low-cost, easily scalable MWCNT pin-rolled eraser-based pressure and strain sensor has huge potential in applications such as artificial e-skin in flexible electronics and medical diagnostics, in particular in surgery as it provides high spatial resolution without a complex nanostructure architecture.

  1. Weighting-Based Sensitivity Analysis in Causal Mediation Studies

    Science.gov (United States)

    Hong, Guanglei; Qin, Xu; Yang, Fan

    2018-01-01

    Through a sensitivity analysis, the analyst attempts to determine whether a conclusion of causal inference could be easily reversed by a plausible violation of an identification assumption. Analytic conclusions that are harder to alter by such a violation are expected to add a higher value to scientific knowledge about causality. This article…

  2. The Study of Factors Relevant to Skin Cancer Preventive Behavior in Female High School Students in Yazd Based on Protection Motivation Theory

    OpenAIRE

    mohammad hosein baghiyanimoghadam; soheila mohammadi; mohammad taghi norbala; seed saeed mazlomi

    2010-01-01

    Introduction: Skin cancer is the most prevalent type of cancer in Yazd, and childhood and adolescence are particularly important time for preventing later skin cancer risk. The goal of this study is to assess the factors relevant to skin cancer preventive behavior in female high school students in Yazd based on protection motivation theory. Methods: Participants in this cross- sectional study were 360 female students from 4 high schools in Yazd. Data were gathered through a self- report quest...

  3. Topical retinoids in the management of photodamaged skin: from theory to evidence-based practical approach.

    Science.gov (United States)

    Darlenski, R; Surber, C; Fluhr, J W

    2010-12-01

    Skin, being exposed directly to the environment, represents a unique model for demonstrating the synergistic effects of intrinsic and extrinsic factors on the ageing process. Ultraviolet radiation (UVR) is the major factor among exogenous stressors responsible for premature skin ageing. The problem of skin ageing has captured public attention and has an important social impact. Different therapeutic approaches have been developed to treat cutaneous ageing and to diminish or prevent the negative effects of UVR. Topical retinoids represent an important and powerful class of molecules in the dermatologist's hands for the treatment of photodamaged skin. Since their introduction more than 20 years ago, topical retinoids have shown beneficial efficacy and good safety profiles in the management of photodamaged skin, and as therapeutic anti-ageing agents. This review provides a brief retrospective of the development of topical retinoids in the treatment of photodamaged skin, elucidates their mechanism of action, delineates their use and addresses clinical, pharmaceutical and regulatory issues in connection with their intended use. © 2010 The Authors. BJD © 2010 British Association of Dermatologists.

  4. Factors that affect skin aging: a cohort-based survey on twins.

    Science.gov (United States)

    Martires, Kathryn J; Fu, Pingfu; Polster, Amy M; Cooper, Kevin D; Baron, Elma D

    2009-12-01

    To identify environmental factors that correlate with skin photoaging, controlling for genetic susceptibility by using a questionnaire administered to twins. The survey collected information about each participant's Fitzpatrick type, history of skin cancer, smoking and drinking habits, and weight from a cohort of twins. Clinicians then assigned a clinical photodamage score to each participant. The annual Twins Days Festival in Twinsburg, Ohio. A voluntary cohort of twins from the general community, mostly from Ohio, Pennsylvania, and the northeastern United States. The survey was completed on a voluntary basis by sets of monozygotic (MZ) and dizygotic (DZ) twins. A total of 130 surveys taken by 65 complete twin pairs were analyzed. Skin aging was assessed using a validated photographic scale of photodamage, graded by such characteristics as wrink